Assessing outcomes of tinnitus intervention.

J Am Acad Audiol 25:76–105 (2014)

Review Assessing Outcomes of Tinnitus Intervention DOI: 10.3766/jaaa.25.1.6 Craig W. Newman* Sharon A. Sandridge* Gary P. Jacobson†

Abstract Background: It has been estimated that as many as 50 million Americans do experience or have experienced tinnitus. For approximately 12 million of these individuals, tinnitus makes it impossible for them to carry out normal everyday activities without limitation. These are the patients that present to audiology clinics for assessment and management. The tinnitus evaluation includes the measurement of acoustical characteristics of tinnitus and the impact that this impairment has on health-related quality of life (HRQoL). Tinnitus is a disorder that often occurs as a result of auditory system impairment. The impairment for some can impart an activity limitation and a participation restriction (i.e., tinnitus-related disability or handicap, respectively). The goal of tinnitus management is to reduce, or eliminate, activity limitations and participation restrictions by reducing or eliminating a patient’s perception of tinnitus or their reaction to tinnitus. Implicit in this statement is the assumption that there exist standardized measures for quantifying the patient’s tinnitus perception and their reaction to it. If there existed stable and responsive standardized tinnitus measures, then it would be possible to compare a patient’s tinnitus experience at different time points (e.g., before and after treatment) to assess, for example, treatment efficacy. Purpose: The purposes of the current review are to (1) describe psychometric standards used to select outcome measurement tools; (2) discuss available measurement techniques and their application to tinnitus evaluation and treatment-related assessment within the domains established by the World Health Organization’s International Classification of Functioning, Disability and Health; (3) list and briefly describe self-report tinnitus questionnaires; (4) describe how valuation of tinnitus treatment can be assessed using economic models of treatment effectiveness; and (5) provide future directions including the development of a tinnitus outcomes test battery and treatment-related study designs. Research Design: Retrospective literature review Conclusions: Although psychometrically robust measures of tinnitus HRQoL do exist, there is no unanimity in, for example, what tests should be included in the tinnitus assessment, and how studies of HRQoL should be conducted. The current authors suggest that future studies employ more rigorous designs and contain (minimally) the following characteristics: (1) utilization of randomized control groups and blinding; (2) appropriate statistical testing including “dropouts” that should be used in an “intention to treat” analysis rather than elimination from the final data set; (3) long-term follow-up assessment to evaluate responsiveness; (4) appropriate inclusion criteria to avoid “ceiling” and “floor” effects; and (5) suitable sample sizes based on the application of power analyses. Key Words: Cost-effectiveness, health-related quality of life, outcomes, responsiveness, tinnitus Abbreviations: BDI 5 Beck Depression Inventory; C/E 5 cost-effectiveness ratio; CI 5 confidence interval; CUA 5 cost-utility analysis; GAD-7 5 Generalized Anxiety Disorder-7; HADS 5 Hospital Anxiety and Depression Scale; HRQoL 5 health-related quality of life; NRS 5 numeric rating scale; NTC 5 Nottingham Tinnitus Clinic; NTT 5 Neuromonics Tinnitus Treatment; PCS 5 percentage change score; PGIC 5 Patient’s Global Impression of Change; PHQ-9 5 Patient Health Questionniare-9; PSQI 5 Pittsburgh Sleep Quality Index; QALY 5 quality-adjusted life years; rxx 5

*Head and Neck Institute, Cleveland Clinic; †Division of Audiology, Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences Craig W. Newman, Ph.D., Head and Neck Institute/A71, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; E-mail: [email protected]

76 Delivered by Ingenta to: University of Massachusetts - Amherst IP : 128.119.168.112 On: Wed, 03 Sep 2014 15:48:38

Tinnitus Outcomes/Newman et al

retest/stability coefficient; SE 5 standard error of measurement; SF-36 5 Medical Outcomes Study Short Form 36; SG 5 sound generator; TFI 5 Tinnitus Functional Index; THI 5 Tinnitus Handicap Inventory; THQ 5 Tinnitus Handicap Questionnaire; TPQ 5 Tinnitus Problems Questionnaire; TRI 5 Tinnitus Research Initiative; TRQ 5 Tinnitus Reaction Questionnaire; VAS 5 visual analogue scale; WHOICF 5 World Health Organization International Classification of Functioning, Disability and Health

C

linical outcomes serve as quantifiable indicators that gauge the impact of treatment on a patient’s symptoms, functioning, well-being, and healthrelated quality of life (HRQoL)—all of which are influenced by the individual’s experiences, beliefs, expectations, and perceptions (Crosby et al, 2003; Dworkin et al, 2008). In this connection, the importance of outcomes assessment continues to increase as the demand to document the efficacy and effectiveness of intervention efforts to patients, other clinicians, accreditation bodies, and policy makers escalates. In general, the aim of outcomes assessment is to detect true and meaningful treatment-related changes that are important to the patient (AHRQ, 2012). Specific to tinnitus, treatment outcome endpoints include perceived relief from the distressing consequences of this auditory symptom (e.g., sleep disturbance, anxiety, depression, irritation, concentration difficulty, loss of control) that affects sufferers’ HRQoL (Langguth, 2011). When evaluating clinical intervention outcomes, clinicians need to acknowledge that the patient may expect that the tinnitus ceases completely or at least becomes quieter. The assessment of tinnitus outcomes (i.e., changes in HRQoL that have occurred secondary to treatment) have implications for tracking clinically meaningful changes in patient function over time; improving “doctorpatient” communication; setting realistic treatment goals and expectations; and incorporating the patient’s perspective of clinical treatment into the overall management plan, thereby empowering the patient in the management process. Empowerment not only improves patient satisfaction with care but also serves to increase compliance with, and adherence to, the treatment plan (Greenhalgh and Meadows, 1999). The purposes of this review are to (1) describe psychometric standards used to select outcome measurement tools, focusing on the importance of responsiveness; (2) discuss available measurement techniques and their application to tinnitus evaluation and treatment-related assessment within the domains established by the World Health Organization’s International Classification of Functioning, Disability and Health (WHO-ICF; World Health Organization, 2001); (3) list and briefly describe viable self-report tinnitus questionnaires; (4) describe how valuation of tinnitus treatment can be assessed using economic models of treatment effectiveness; and (5) provide future directions including the development of a tinnitus outcomes test battery and treatment-related study designs.

WHO-ICF

W

ithin the context of a biopsychosocial model, the WHO-ICF (World Health Organization, 2001) provides a conceptual framework for evaluating HRQoL issues underlying tinnitus outcomes assessment (Tyler, 1993, 2000; Newman and Sandridge, 2004, 2009; Meikle et al, 2008; Ramkumar and Rangasayee, 2010). With this model in mind, the goals of tinnitus management are to improve an individual’s HRQoL by (1) extinguishing or habituating the sound/s associated with tinnitus impairment (i.e., dysfunction of the auditory system resulting in the sensory perception of tinnitus) and (2) reducing the negative psychosocial impact of tinnitus resulting in activity limitation (i.e., effect of impairment on reducing the individual’s ability to function in a normal manner) and participation restriction (i.e., psychosocial consequences of impairment and activity limitation resulting in the need for extra effort and reduced independence). Figure 1 summarizes the interaction among the individual domains of the WHO-ICF (World Health Organization, 2001) schema and how each domain relates to tinnitus and overall HRQoL acknowledging that all will be influenced by both personal and environmental factors.

Figure 1. Illustration of the interaction among the individual domains of the WHO-ICF (World Health Organization, 2001) schema and how each domain relates to tinnitus and overall health-related quality of life (HRQoL) within the context of personal and environmental factors.


Journal of the American Academy of Audiology/Volume 25, Number 1, 2014

A number of measurement tools have been used to evaluate tinnitus and assess treatment-related outcome for each of the three WHO-ICF (World Health Organization, 2001) domains related to the tinnitus experience (Table 1). Examination of outcomes data derived from one or more of these instrument types addresses questions of treatment effectiveness (e.g., Does the tinnitus treatment work in reducing tinnitus awareness or distress?), treatment efficiency (e.g., Does one type of tinnitus treatment work better than another in improving sleep and concentration difficulty?), and cost-effectiveness (e.g., Does one type of tinnitus treatment provide sufficient relief in relations to the cost/price of the treatment?) (Olswang, 1998; Johnson and Danhauer, 2002). For all stakeholders involved in the tinnitus management process, responses to these questions about treatment outcome have become an increasingly important part of clinical and policy decision making especially in our current health-care climate. PSYCHOMETRIC CONSIDERATIONS PRIOR TO SELECTING OUTCOME MEASUREMENT TOOLS

T

he clinical and research usefulness of instruments designed to evaluate tinnitus and assess treatmentrelated change is determined by their psychometric characteristics and adequacy (Demorest and Walden, 1984; Demorest and DeHaven, 1993; Hyde, 2000; Shum et al, 2006). The following lists a few key areas of psychometric standards that are important to consider when evaluating and selecting a “candidate” tinnitus assessment tool—most are well-known. For an in-depth discussion of these and other psychometric standards for patient-based outcome measurement development and usage, the interested reader is referred to Fitzpatrick et al (1998), Hyde (2000), and Langguth, Searchfield, et al (2011). One psychometric construct is relatively new

to audiology measurements, responsiveness, and will be discussed in more detail below. Appropriateness: Are the content domains (content validity) of the instrument appropriate to the concerns of the patient and clinician or to the questions that the clinical trial is designed to address? Reliability: Does the instrument produce results that are reproducible and internally consistent? Validity: Does the instrument measure what it claims to measure? Precision: How precise are the scores, or numerical properties, of the instrument? Interpretability: How interpretable, or meaningful, are the scores of the instrument? Acceptability: Is the instrument acceptable to the patient (e.g., method of administration; layout and appearance of questionnaire; length; translation and cultural applicability)? Feasibility: Is the instrument easy to administer and score? Responsiveness: Does the instrument detect changes over time that matter to the patient?

Responsiveness The psychometric property of responsiveness is of particular interest when selecting a tinnitus instrument that will be used to detect treatment-related changes in performance. The concept of responsiveness is based on the simple construct that the goal of treatment is to bring about a change in health status or HRQoL. Accordingly, the assessment tool’s ability to be responsive to clinically significant changes in treatment effects is an important prerequisite for the use of such instruments— especially in clinical trials (Norman et al, 1997). For studies focusing on treatment evaluation, Guyatt and colleagues (1993) distinguished between two types

Table 1. Primary Measurement Tools Used to Evaluate Three Domains of the World Health Organization’s International Classification of Functioning, Disability and Health Schema (WHO-ICF; World Health Organization, 2001) Measurement technique

Impairment

Psychoacoustic measures Pitch matching Loudness matching Minimum masking levels Residual inhibition Numeric rating scale Visual analog scale Open-ended questionnaire Diary/journal entry Patient global impression of change scale Disease/condition-specific measure Dimension-specific measure Generic instrument measure

X X X X X X X X

Activity limitation

Participation restriction

X X X X X X X

X X X X X X


X


of tools: discriminative instruments (tools used to measure HRQoL differences between patients at a point in time in order to establish their clinical status and treatment needs) and evaluative instruments (tools used to measure HRQoL differences within a patient during a period of time in order to determine treatment-related changes). If intervention results in a change in HRQoL, clinicians and researchers want to be confident that they will detect those differences, even if small (Guyatt et al, 1993). Thus, instruments utilized to detect changes must have a high sensitivity to change, or responsiveness. Several statistical approaches have been used to evaluate responsiveness (quantitative expressions of the magnitude and meaning of health status change). The following section focuses on two statistical approaches designed to detect clinically significant improvements, namely effect size (Kazis et al, 1989) and change scores (Demorest and Walden, 1984; Demorest and DeHaven, 1993; Hurst and Bolton, 2004). Effect Size Effect size is a statistical method used to compare outcomes by assessing the magnitude of treatmentrelated changes over time. Note that effect size calculations are used for evaluating group data and are not an appropriate metric for individual data. Several equivalent formulae have been used to calculate effect size (Norman et al, 1997). This statistical technique yields a value reflecting observed treatment effects in terms of standard deviation units of the item or questionnaire in use (Lipsey, 1990; Stewart and Archbold, 1992). More specifically, effect size may be calculated for treatment studies involving pre- and posttreatment measures using the equation seen in Table 2A (Meikle et al, 2007). For studies in which a treatment group is compared to a control group, effect size is calculated using the equation seen in Table 2B. Guidelines established for interpreting effect size values (Cohen’s d) as proposed (Cohen, 1988) for outcome studies are d , 0.20, inconsequential or nonsignificant; d 5 0.20– 0.50, small; d 5 0.5–0.80, moderate; and d . 0.80, large. Using these benchmarks, larger d scores are representative of outcome measures yielding greater responsiveness (i.e., larger treatment effects). It is important to determine

effect sizes in order to increase the statistical power of clinical studies and to develop questionnaires that demonstrate high responsiveness to treatment-related changes (Lipsey, 1990; Meikle et al, 2007). Unfortunately, developers of HRQoL tinnitus questionnaires have not routinely included calculations of effect size in their initial norming and standardization studies. Only recently have Meikle and colleagues (2012) designed a questionnaire, the Tinnitus Functional Index (TFI), with the objectives of not only assessing the severity and negative impact of tinnitus (discriminative function) but also measuring responsiveness to treatment (evaluative function) based on effect size data. The TFI will be discussed in more detail below.

Change Scores (Assessing Differences between Scores on Two Occasions) If a patient’s scores on two occasions are used to estimate whether a true change has occurred on a questionnaire, test-retest reliability/stability data, standard error of measurement (SE), and 95% confidences intervals (CIs) of the tool being used must be taken into account (Demorest and Walden, 1984; Demorest and DeHaven, 1993). Retest reliability is concerned with short-term, day-to-day fluctuations in scores whereas stability reflects the magnitude of agreement between two scores over longer durations (e.g., months). Although several current tinnitus questionnaires have test-retest reliability data available (e.g., Tinnitus Handicap Questionnaire [THQ], Kuk et al, 1990; Tinnitus Reaction Questionnaire [TRQ], Wilson et al, 1991; Tinnitus Handicap Inventory [THI], Newman et al, 1998), there is little information about long-term stability. This poses a problem for studies documenting effectiveness of treatment with precision over the long term (e.g., habituation therapy; cognitive-behavioral therapy). The 95% CI for a true change between two administrations of a questionnaire may be calculated by the formula (Demorest and Walden, 1984) seen in Table 2C. The standard error (SE; Table 2D) is obtained from an estimate of the retest reliability/stability coefficient (rxx) and the standard deviation (SD) of the scores (Demorest and Walden, 1984).

Table 2. Formulas for Calculating Responsiveness Description

Calculation

A. Effect size for pre- and posttreatment studies

Effect size ¼

Mean difference score for group Standard deviation of difference scores

B. Effect size for comparing control group and treatment group

Effect size ¼

Intervention group mean 2 Control group mean Average standard deviation

pffiffiffi CI ¼ 62 2SE pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi SE ¼ SD 1 rxx

C. Calculation for 95 percent confidence interval (CI) D. Calculation for standard error used in the CI formula E. Calculation for percentage change score (PCS)

PCS ¼

Pretreatment score2Posttreatment score 3100 Pretreatment score



Newman and colleagues (1998) applied the calculations proposed by Demorest and Walden (1984) to determine 95% CIs (critical differences scores) for data obtained on test-retest administration of the THI. Based on these calculations they determined that a $20 point difference score is necessary to use the THI as an index of change. Percentage change score (PCS) is an alternative standardized measure that is easily interpreted especially when different outcome measures are in use. In studies where there is variability in baseline scores, either as a function of different measurement tools or intersubject variability, PCS normalizes the difference score to allow easy clinical comparisons. That is, PCS reflects relative scores for comparison purposes rather than absolute difference scores. PCS are calculated using the equation seen in Table 2E. PCS have been used to evaluate clinical outcomes for the Neuromonics Tinnitus Treatment (NTT; Davis et al, 2007; Davis et al, 2008; Hanley and Davis, 2008). For example, Hanley and colleagues (2008) calculated PCS, based on pre- and posttreatment responses to the TRQ (Wilson et al, 1991), for fee-paying patients seen in seven different private practices in Australia. Patients were assigned to 1 of 3 cohorts based on a set of predetermined suitability criteria for NTT (e.g., Tier 1 = most suitable; Tier 3 = least suitable). The mean treatment-related improvements using PSC for the three cohorts studied (from most to least suitable) were 72%, 49%, and 32%, respectively. After 6 mo of treatment, 92% (Tier 1), 60% (Tier 2), and 39% (Tier 3) exceeded the criteria considered to indicate significant improvement (i.e., PCS [reduction] of at least 40% on the TRQ). The latter study illustrates the application of PCS for monitoring the effects of intervention for different subject samples. TYPES OF MEASUREMENT TECHNIQUES

A

s shown in Table 1, there are several types of measurement techniques that have been used to evaluate tinnitus and quantify tinnitus outcome along the dimensions of tinnitus impairment, activity limitation, and participation restriction (WHO-ICF; World Health Organization, 2001). These approaches are both qualitative (e.g., not score driven; open-ended and descriptive; not assigned a predetermined value per item) and quantitative (e.g., score driven; result of a psychophysical measurement procedure; response on a questionnaire that can be summed and/or averaged, resulting in a total or subscale score) in nature (Newman and Sandridge, 2004). Psychoacoustic Measurement Psychoacoustic measurement procedures provide the clinician and researcher a method for assessing the

sensory characteristics of the tinnitus experience. In the clinical setting, the following measurements are typically conducted as part of the tinnitus evaluation and may be used to document treatment-related tinnitus impairment changes: Pitch matching: Patients equate the pitch of an externally generated pure-tone or narrowband noise to the most prominently perceived tinnitus. Loudness matching: Patients equate the loudness of an externally generated pure-tone or narrowband noise to the overall perceived tinnitus. Minimum masking levels: Patients identify the minimum level of a broadband noise (BBN) required to completely mask the perceived tinnitus. If the tinnitus cannot be masked, patients report the minimum level of a BBN that changes the perception of the tinnitus (e.g., louder or softer). Residual inhibition: Patient reports the time between when the tinnitus has been partially or completely suppressed after the externally generated masking stimuli has been turned off. Tyler (2000) suggested that a primary reason for conducting psychoacoustic measurements of tinnitus is to help quantify treatment outcome and effectiveness. Additionally, he indicated that psychoacoustic data are helpful for reassuring the patient that the tinnitus is real; demonstrating the acoustic characteristics of the tinnitus to the patient and significant other; selecting specific treatment options (e.g., hearing aid, versus sound generator only, versus combination device); and assisting in medico-legal cases. Schaette et al (2010), on the other hand, demonstrated that sound therapy was more effective when tinnitus was matched to frequencies less than 6000 Hz, therefore suggesting that pitch matching may have clinical efficacy. The consensus statement from the Tinnitus Research Initiative meeting (Langguth et al, 2007) proposed that loudness matches and maskability should be considered primary psychoacoustic outcome measures in tinnitus treatment trials. Although measurement protocols for conducting the psychoacoustic battery are not currently standardized, several approaches have been recommended for clinical use (Henry and Meikle, 2000; Tyler, 2000; Vernon and Meikle, 2003). Meikle and colleagues (2008) suggested that loudness matching and minimum masking levels can document treatment effects because test-retest data are available. In this connection, Vernon (1996) indicated that patients are able to reliably perform loudness matching tasks because they have an “internal standard” to compare to the externally generated stimuli. In this way, loudness matches provide a psychoacoustic metric for evaluating treatment effects over time (Johnson et al, 1993). Jacobson et al (2000) also



reported that individuals without tinnitus can “imagine” a tinnitus signal that is stable and may serve as an “internal standard.” In addition to loudness matching, minimum masking level (MML) has also demonstrated adequate test-retest reliability as long as the patient does not experience residual inhibition during the testing period (Vernon and Meikle, 2003; Meikle et al, 2008). A major drawback in utilizing psychoacoustic measurement as an outcome method, however, is that there are currently no standardized protocols for conducting these tests, although a few computer-assisted techniques are being evaluated that hold promise for acquiring reliable data (Henry et al, 2009). Scaling Responses/Direct Estimation Techniques Scaling response techniques are easy to administer, brief in nature, economical in space, provide high measurement resolution, and are straightforward to score and interpret (Meikle et al, 2008). In general, direct estimation techniques are continuous judgment response scales designed to elicit a direct quantitative estimate of the magnitude of an attribute (Streiner and Norman, 1994) from the patient. Numeric Rating Scales (NRSs) Psychoacoustic attributes of tinnitus are commonly quantified using NRS. For example, the patient is asked to rate his or her judgment of tinnitus pitch and loudness on a 10-point scale (Figs. 2A and B). For each NRS, a descriptive anchor at each end of the scale is important to provide a context in which the patient can make the most appropriate judgment (e.g., for pitch, “very low” and “very high”; for loudness, “very faint” and “very loud”). Further, it may be helpful to the patient to present a short instructional set before each rating scale. For example, for the pitch NRS, the instructions might read: “Describe the most prominent PITCH (like piano keys from low to high) of your tinnitus by circling ONE of the numbers below. Number 1 is a very low pitch similar to a fog horn, and number 10 is like a very high pitched whistle.” Using NRS, Stouffer and Tyler (1990) reported that the average value for the subjective rating of tinnitus pitch was 7.12 (SD 5 2.3) on a 10-point scale while the average loudness rating was 6.3 (SD 5 2.3) on a 10-point scale. NRSs are also useful in providing numerical estimates of tinnitus severity or dimensions of HRQoL. Figures 2C and D show examples of how a 10-point NRS was used to quantify dimensions of activity limitation (e.g., example relates to sleep disturbance) and participation restriction (e.g., example relates to stress on personal relationships). NRSs have been used extensively to quantify and monitor treatment-related effects

Figure 2. Numeric rating scales (NRSs) for pitch, loudness, sleep disturbance, and personal relationships.

for chronic pain (Streiner and Norman, 1994), which is often compared to tinnitus (Møller, 2007). Unfortunately, there is a scarcity of data regarding reliability and responsiveness of this scaling technique as it relates to tinnitus. Visual Analog Scales (VASs) The VAS is an alternative scaling technique that employs a line of fixed length (typically 100 mm), with anchors at the end of the line appropriate for the attribute being measured. The patient is required to place a mark, such as an “X” or a vertical line, on the horizontal line corresponding to his or her perceived tinnitus judgment. In this way, the clinician or researcher is able to quantify the respondent’s judgment by simply measuring the distance (in mm) between the left anchor and the point at which the patient marked horizontal the line. Figures 3A–C illustrate the use of the VAS to evaluate impairment (e.g., loudness), activity limitation (e.g., annoyance), and participation restriction (e.g., interference with social/leisure activities), respectively. The VAS can also be a useful technique as a measurement of change (Scott and Huskisson, 1979). For example, the VAS could be used to evaluate the degree of a patient’s perceived improvement following a 6 mo treatment with sound therapy. The baseline VAS would be given to the patient who would be asked to indicate the



approaches that have been used by clinicians to obtain descriptive information about a patient’s reaction to and complaints about tinnitus before and after treatment, namely open-ended questionnaires and daily monitoring diaries/journals. Open-Ended Questionnaire

Figure 3. Visual analog scales (VASs) for loudness, annoyance, and interference with social/leisure activities.

change by placing a second “X” indicating their present state. The difference between the two marks would represent degree of improvement or worsening of tinnitus perception. Recently, the psychometric adequacy of the VAS was evaluated in a sample of patients with chronic tinnitus. Adamchic et al (2012) showed that the VAS not only had good test-retest reliability and convergent validity for measuring self-perceived tinnitus annoyance and loudness. In addition, they determined that a difference of at least 10 points, on a 100-point scale, was needed to detect a minimally clinically identifiable difference. Although the VAS provides some precision in measurement, there is no guarantee that the response accurately and precisely reflects the underlying perceptual attribute being measured (Streiner and Norman, 1994). Further, the VAS may be difficult for specific patient populations to complete, including the elderly and those with physical or visual problems (Gagliese, 2001), thereby limiting their applicability and test-retest reliability. Similar to the use of NRS, there are limited data available demonstrating the psychometric adequacy for quantifying clinically significant change on the VAS following tinnitus intervention. Patient-Based Outcome Measures A number of patient-based outcome measures have been developed that differ in content and intended purpose. As shown in Table 1, these measures are especially useful for evaluating tinnitus activity limitation and participation restriction. Individualized Measures Individualized tinnitus measures are qualitative in nature and are not score-driven. There are two

The Tinnitus Problems Questionnaire (TPQ; Tyler and Baker, 1983) uses an open-ended format where the patient is simply asked the following, “Please make a list of the difficulties that you have as a result of your tinnitus. List them in order of importance, starting with the biggest difficulties. Write down as many of them as you can.” Based on data obtained from 72 members of a tinnitus self-help group responding to the TPQ, the top five difficulties included getting to sleep (57% of respondents); persistence of tinnitus (49% of respondents); understanding speech (38% of respondents); despair, frustration, depression (36% of respondents); and annoyance, irritation, inability to relax (35% of respondents). A major advantage of the TPQ, or any open-ended tool, compared to fixed-item structured measures such as the THQ (Kuk et al, 1990) or THI (Newman et al, 1996) is that the patient is not limited by the items on the assessment or with the fixed response set (e.g., Yes, Sometimes, No). That is, patients may find items on the measurement tool not relevant to them personally or find the response options not representative of their particular answer. Conversely, a limitation associated with the application of the TPQ for outcomes assessment is that the responses cannot be quantified across time or patients (Tyler, 1993) since it is possible, for example, that 10 patients could volunteer 10 unique responses. Diary/Journal Entries An alternative individualized measure is the maintenance and completion of a diary/journal by patients. This technique is used to assess patterns of tinnitus complaints, both sensory (e.g., changes in pitch and loudness) and functional disturbances (changes in sleep patterns and tinnitus awareness) that may be associated with lifestyle changes (e.g., diet, exercise, medications, noise exposure, stress). The use of diaries/ journals may be particularly helpful for the psychologists on the tinnitus management team in designing cognitive-behavioral therapy treatment plans by identifying unhelpful thoughts (Hallam and McKenna, 2006). In addition, monitoring diary/journal entries before and after intervention may also provide insight into changing thoughts of the patient regarding selfappraisal of the consequences, meanings, and implications of tinnitus. In this connection, McKenna and



Daniel (2006) devised a sleep diary used in tinnitus management where data such as time in bed and time asleep are calculated and graphed as feedback to the patient over the course of treatment. There are a number of limitations, however, associated with keeping diaries/journals including response bias, exaggeration, and most potentially problematic from a rehabilitative perspective is the increasing attention given to the tinnitus that is part of the diary/journal entry process (Henry and Wilson, 2001). In fact, ongoing shifts in attention to the tinnitus throughout the day, or “self-checking” behavior by the patient, may actually be counterproductive to the habitation of the tinnitus response so important to psychologic (e.g., acceptance and commitment therapy) and audiological (e.g., sound therapy and counseling) management strategies. Moreover, the use of a diary/journal in outcomes assessment is limited by the lack of any psychometric data regarding validity, reliability, and responsiveness. Summary/Patient’s Global Impression of Change (PGIC) Scale A single summary (or overall global) item has potential for documenting the effects of tinnitus treatment outcome. To assess a patient’s own impression to change following intervention, the Patient’s Global Impression of Change (PGIC) scale can be used. This single question asks the patient to indicate the amount of change noted following intervention, from “much better” through “no change” (Hurst and Bolton, 2004). Because patients provide a self-report judgment about the meaning of change following treatment, a PGIC item has the potential to serve as an external criterion “gold standard” of clinically important overall changes (Farrar et al, 2001). The most obvious advantage of this type of self-report query is its brevity, requiring the least time demand on both the patient and clinician. Table 3 illustrates a PGIC scale that could be used to quantify a patient’s perception of overall treatment

effectiveness on quality of life. In this example, a seven-point scale is utilized to assess how using a sound generator affected patients’ ability to cope with their tinnitus. The scale values can be defined a priori to indicate from clinically significant improvement (scores of 5, 6, or 7 in this example) to minimal change in response to the treatment (scores of less than 3 in this example). The last column in Table 3 contains the number of observations for each category. In this example, the clinically improved values represent 25, 54, and 76% of tinnitus patients as clinically improved using cutoff scores on the PGIC of 7, $6, and $5, respectively. In contrast, only 6% fell within the minimal change categories (less than a 3 on the scale). The application of summary items designed to evaluate improvement in function has been found in the tinnitus literature including studies evaluating tinnitus masking (Hazell et al, 1985) and drugs (Dobie et al, 1993). Although a single item measure may give the clinician and researcher a quick “snapshot” about treatment-related changes, there are a number of limitations associated with this technique (Norman et al, 1997). These include a paucity of information about how well these measures perform in clinical trials (Hurst and Bolton, 2004); a lack of psychometric data including reliability, validity, and responsiveness such as effect size (Meikle, et al, 2008); psychological difficulty in the ability to make judgments of change by patients in that they must be able to quantify both their present state (i.e., posttreatment) and their initial state (i.e., pretreatment) and then perform a “mental subtraction” (Norman et al, 1997). Disease/Condition-Specific Measures Self-report tinnitus disease/condition-specific questionnaires have gained widespread recognition among clinicians as useful tools for quantifying activity limitation and participation restrictions, grading tinnitus severity, and monitoring outcome when used in a pre- and posttreatment paradigm (AHRQ, 2012). These

Table 3. Example of the Use of a Patient’s Global Impression of Change (PGIC) Scale Since you began using sound generators, how would you describe the change (if any) in your ABILITY TO COPE WITH YOUR TINNITUS? (Please check ONE box only.)

1. 2. 3. 4. 5. 6. 7.

No change (or worse). Almost the same, hardly any change at all. A little better, but no noticeable change. Somewhat better, but the change has not made any real difference. Moderately better, and a slight but noticeable change. Better, and a definite improvement that has made a real and worthwhile difference. A great deal better, and a considerable improvement that has made all the difference.

h h h h h h h

Number of patients in each improvement category (n = 100) 2 4 6 12 22 29 25

Source: Adapted from Hurst and Bolton, 2004.



HRQoL measurement tools provide information that may not be gleaned from tinnitus impairment assessment. That is, a low correlation has been shown to exist among psychoacoustic measures (e.g., pitch and loudness ratings) and perceived tinnitus severity and annoyance (Meikle et al, 1984; Jakes et al, 1985). For example, a loudness rating of 9 on a 10-point NRS, suggesting very loud tinnitus, may be associated with minimal annoyance. In contrast, a rating of 3 points (i.e., low loudness rating) on the NRS may be causing significant stress to the patient. Moreover, conducting an item-analysis of self-report questionnaire responses provides clinicians an opportunity to identify specific problems that can be addressed through counseling or referral to another provider. In addition to clinical application, tinnitus questionnaires have utility for the researcher in determining subject selection criteria (Langguth, Searchfield, et al, 2011). For example, inclusion criterion for a study based on a cutoff score for a particular questionnaire would be helpful for selecting only those patients demonstrating a given level of perceived tinnitus activity limitation/participation restriction. This would help to eliminate a “floor effect” when trying to show treatment-related changes. Moreover, assuming that equivalent measures are used, determination of a preselected level of severity is especially important for betweensubject study designs in order to reduce the threat to internal validity of treatment studies. That is, it is important that the composition of two or more treatments groups be comparable at the initiation of each treatment approach (e.g., drug versus sound therapy versus psychological) so that differences may be attributed to a treatment modality (Newman and Sandridge, 2004). Moreover, serial applications of self-report measures allow researchers to demonstrate changes in the functional status of patients over time, providing insight into the stability of intervention efforts. Over the past two decades, a number of questionnaires have been developed to evaluate the negative consequences of tinnitus on an individual’s HRQoL. Table 4 provides a summary of the major self-report questionnaires that evaluate the multidimensional domains of activity limitation, participation restriction as well as other dimensions such as cognitive reactions to tinnitus, coping ability, and self-efficacy (confidence individuals have in their abilities to perform specific tasks, goals, and behaviors). The array of questionnaires in Table 4 reflect the range of psychosocial effects of tinnitus, and many are well-suited to capture the aspects of an individual’s everyday life that might be negatively affected yet amenable to treatment. For a more detailed discussion of the individual questionnaires summarized in Table 4, the reader is referred to Newman and Sandridge (2004) and Langguth, Searchfield, et al (2011)

When used to assess outcome, administration of a self-report questionnaire must be conducted at the initiation of treatment in order to obtain a baseline measurement. Accordingly, a reduction in self-perceived HRQoL (which may or may not be accompanied by changes in tinnitus impairment) would be reflective of the subjective benefit obtained from a particular tinnitus treatment (e.g., sound therapy, medication, cognitive behavioral therapy [CBT]). In contrast, no change or an increase in perceived difficulties would suggest that intervention efforts are not providing sufficient benefit and that additional and/or alternative approaches should be considered. In order to make these clinical decisions, the tinnitus questionnaire should have, minimally, adequate test-retest reliability and be able to be responsive to the effects of treatment (Lipsey, 1990; Kazdin, 2003). Most of the questionnaires outlined in Table 4 are psychometrically robust showing high internal consistency reliability, construct validity, and high test-retest reliability, making them adequate for discriminative purposes at the time of the initial tinnitus assessment (Meikle et al, 2008). For example, the TRQ (Wilson et al, 1991) and the THQ (Kuk et al, 1990) are useful for grading tinnitus severity. Most of the questionnaires summarized in Table 4 were not originally designed nor validated to measure effectiveness; however, there is general consensus that questionnaire scores do indeed provide information about treatment-related changes and continue to remain as primary outcome measurement tools (Langguth, 2011). The THI (Newman et al, 1996, 1998) is one of the most widely used self-report tinnitus measures for documenting treatment effects due to the availability of change scores (Langguth, Searchfield, et al, 2011). As described earlier, Newman and colleagues (1998) determined that a change in the total THI score of at least 20 points (based on 95% confidence intervals) suggests that treatment is statistically and clinically effective. In addition, four severity categories were established (based on calculated quartiles): 0–16 points, no handicap; 18–26 points, mild handicap; 38–56 points, moderate handicap; 58–100 points, severe handicap. Subsequently, a fifth category (catastrophic) for scores greater than 76 points was proposed by McCombe et al (2001). The classification schemes offer an approach for clinicians to quantify treatment-related change. That is, the classifications make it possible to monitor movement from one category to another over time with and without intervention. This method provides the researcher an opportunity to evaluate group differences using nonparametric statistics such as a x2 analysis. More recently, in a sample of 210 patients from Argentina, Belgium, Brazil, and Germany, a minimum clinically significant change in the THI score was defined by a pre- and posttreatment difference of 7 points, based


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16

26

Subjective Tinnitus Severity Scale (STSS; Halford and Anderson, 1991)

Tinnitus Reaction Questionnaire (TRQ; Wilson et al, 1991)

Distress consequences including anger, confusion, annoyance, helplessness, activity avoidance, and panic

Intrusiveness, distress, hearing loss, sleep disturbance, and medication

15

Three factors: Factor 1 (15 items), physical, emotional, social consequences of tinnitus; Factor 2 (8 items), effects on hearing; Factor 3 (4 items), patient’s view of tinnitus

27

Tinnitus Handicap Questionnaire (THQ; Kuk et al, 1990)

Tinnitus Severity Scale (TSS; Sweetow and Levy, 1990)

Sleep disturbance, emotional distress, auditory perceptual difficulties, inappropriate or lack of coping skills

Content domains/factors/subscales

52

Number of items

Tinnitus Questionnaire (TQ; Hallam et al, 1988)

Questionnaire (authors)

Table 4. Summary of Tinnitus Questionnaires

Multiple choice format for each item ranging in score from 1 (no impact) to 4 (most impact) Each item weighted 1 to 3 points (total 5 39 points) Total score calculated by multiplying item score by weight and summing products Yes/no response format 10/16 items earn 1 point for yes response; 6/16 items earn 1 point for no response Scores range: 0–16 with high scores reflecting greater overall severity Five-point scale (0 5 not at all; 4 5 almost all of the time) Score range: 0–104 with higher scores reflecting greater distress

Level of agreement to each statement: true (2 points); partly true (1 point); not true (0 points) Score range: 0–104 points with higher scores reflecting greater tinnitus complaints Level of agreement to each statement between 0 (strongly disagrees) and 100 (strongly agrees) Mean scores calculated with higher scores reflecting greater handicap (need to invert scores from items 25 and 26) Individual scores can be compared against normative percentile data

Response format/scoring

High internal consistency reliability (Cronbach’s a 5 .84) Criterion validity determined by significant correlations with clinician rating of severity High internal consistency reliability (Cronbach’s a 5 .96) High test-retest reliability (r 5 .88) Construct validity supported by moderate to high correlations with clinician ratings and self-report measures of anxiety and depression

High internal consistency reliability for total scale (Cronbach’s a 5 .95), factor 1 (0 a 5 .95), and factor 2 (a 5 .88), with an a of only .47 for factor 3 High test-retest reliability for total (r 5 .89), factor 1 (r 5 .89), and factor 2 (r 5 .90); low for factor 3 (r 5 .50) Adequate construct validity (r . .50) with tinnitus loudness judgments, life satisfaction, hearing thresholds, depression, and general health status Adequate test-retest reliability (r 5 .86)

High internal consistency reliability (Cronbach’s a 5 .91–.95) High test-retest reliability (r 5 .91–.94) Convergent validity with the THQ and TRQ

Psychometric characteristics


85

Effects of tinnitus on work, social activities, and overall quality of life

Three subscales: Functional (11 items), role limitations in mental, social/occupational, physical functioning; Emotional (9 items), anger, frustration, irritability, depression; Catastrophic (5 items), desperation, loss of control, inability to cope and escape, fear of grave disease

Two subscales: Maladaptive coping (18 items); Effective coping (15 items)

25

33

Tinnitus Handicap Inventory (THI; Newman et al, 1996; Newman et al, 1998)

Tinnitus Coping Style Questionnaire (TCSQ; Budd and Pugh, 1996a, 1996b)

Three factors: Factor 1 (9 items), perceived attitudes or reactions of others; Factor 2 (10 items), social support; Factor 3 (9 items), personal and social handicaps

28

12


Number of items

Tinnitus Severity Index (TSI; Meikle, 1992; Meikle et al, 1995)

Tinnitus Handicap/Support Scale (TH/SS; Erlandsson et al, 1992)


Table 4. Continued

86

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Version 1: Three to four levels with varying response choices between items Version 2: Five levels with varying response choices between items Response format: yes (4 points); sometimes (2 points); no (0 points) Total score range: 0–100 points with higher scores reflecting greater handicap Handicap severity categories: no handicap (0–16 points); mild (18–36 points); moderate (38–56 points); severe (58–100 points) Catastrophic category proposed by McCombe et al (2001) for a score .76 points

Five-point scale (1 5 strongly disagree; 5 5 strongly disagree)


Excellent internal consistency reliability (Cronbach’s a 5 .96) High test-retest reliability: total (r 5 .92) and subscales (r 5 .84–.94) Convergent validity with THQ and TQ Construct validity with Beck Depression Inventory, Modified Somatic Perception Questionnaire, symptom rating scales (e.g., sleep, annoyance), tinnitus pitch and loudness 95% confidence interval 5 20 points for clinically significant change Overall responsiveness at detecting improvements from initial clinic visit to 3 and 6 mo postvisits were moderate (effect sizes 5 .56) and large (effect size 5 1.22), respectively (Meikle et al, 2012). Excellent internal consistency reliability for maladaptive subscale (Cronbach’s a 5 .90) and coping subscale (Cronbach’s a 5 .89) Two subscales not significantly correlated (r 5 .13)

Four factors emerged using principal components analysis: general distress, interference, severity, avoidance Construct validity assessed with the THQ showing significant relationships between tinnitus severity and perceived attitudes (factor 1) and between severity and personal and social handicaps (factor 3) Excellent internal consistency reliability (Cronbach’s a 5 .87) Good construct validity with THQ (r 5 .77)



8

40

Self-Efficacy for Tinnitus Management Questionnaire (SETMQ; Smith and Fagelson, 2011)

26

Number of items

International Tinnitus Inventory (ITI; Kennedy et al, 2005)

Tinnitus Cognitions Questionnaire (TCQ; Wilson and Henry, 1998)


Table 4. Continued

Five subscales: Routine tinnitus management (16 items); Emotional response (9 items); Internal thoughts and interaction with others (8 items); Tinnitus concepts (4 items); Devices (3 items)

Effects of tinnitus on hearing, health, sleep, peace of mind, other people, activities, enjoyment of life

Positive (13 items) and negative (13 items) thoughts of tinnitus


0–100 point (percentage) scale, 10-unit intervals. Anchors range from “Cannot do this at all” (no certainty) to “I am certain I can do this” (completely certainty)

Five-point scale (1 5 greater difficulty with tinnitus; 5 5 low difficulty) Low scores reflect more intrusive perception of tinnitus

Five-point scale (0 5 never; 4 5 very frequently) Negative items are scored 0 to 4 Positive items reverse scored 4 to 0 Total score range: 0–104 with higher scores reflecting greater tendency to engage in negative thoughts and low engagement in positive thoughts


Coping subscale significantly associated with measures of tinnitus severity, depression, and anxiety Effective coping subscale significantly associated with tinnitus adjustment measures Excellent internal consistency reliability (Cronbach’s a 5 .91) Excellent test-retest reliability (r 5 .88) Factor analysis supported positive and negative subscales Construct and convergent validity assessed: TCQ showed moderate correlations with TRQ, THQ, and TQ TCQ-negative subscale showed high correlations with tinnitus (tinnitus related distress, handicap, complaint behavior) and nontinnitus (general depression, automatic thoughts, locus of control) measures Excellent internal consistency reliability for English and French versions (Cronbach’s a 5 .91 and .87, respectively) High inter-item correlations (p < 0.05) Unifactorial based on factor analyses Good internal consistency reliability overall and for each subscale (Cronbach’s a 5 .74 to .98) Item-total correlations were moderate or better (.45 to .86) Excellent test-retest reliability for total and subscale scores (intraclass correlations .0.80) Convergent and divergent validity evaluated with a variety of tinnitusrelated measures (e.g., THI, tinnitus loudness ratings, tinnitus distress) were significant, with fair to good relations (range r 5 2.18 to 2.53)



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87

Excellent internal consistency reliability (Cronbach’s a 5 .97) High test-retest reliability (r 5 .78) Good convergent validity with THI (r 5 .86), visual analog scale for severity (r 5 .75), THQ (r 5 .83) Good discriminant validity with Beck Depression Inventory-Primary Care (r 5 .56) Overall responsiveness at detecting improvements from initial clinic visit to 3 and 6 mo postvisits were large (effect sizes 5 .83 and 1.46, respectively). Meaningful reduction to quantify treatment benefit is 13 points Source: Adapted from Newman and Sandridge (2009).

11-point scale (0 to 10) with anchors varying per item All responses summed, divided by number of questions answered, multiplied by 10 Total score range: 0–100 Eight subscales: Intrusive (3 items); Sense of control (3 item); Cognitive (3 items); Sleep (3 items); Auditory (3 items); Relaxation (3 items); Quality of life (4 items); Emotional (3 items) 25 Tinnitus Functional Index (TFI; Meikle et al, 2012)


Table 4. Continued

Number of items





on a calculated effect size of d = 0.5 (medium effect) (Zeman et al, 2011). Zeman and colleagues indicated that these observations serve as the basis for planning future tinnitus treatment studies; however, they cautioned that a number of potential covariables need to be considered when determining treatment-related changes such as THI baseline scores, age, etiology, and duration of tinnitus. In support of its widely accepted application as an outcome measure, Table 5 provides a summary of studies where the THI has been used to demonstrate treatmentrelated effects across a wide range of intervention modalities. Moreover, validated cultural adaptations and translations of the THI are published in at least 15 languages, attesting to its worldwide usage. These include: Danish (Zachariae et al, 2000), Spanish (Herraíz et al, 2001), Korean (Kim et al, 2002), Brazilian Portuguese (Ferreira et al, 2005; Schmidt et al, 2006), German (Kleinjung et al, 2007), Turkish (Aksoy et al, 2007), Italian (Monzani et al, 2008; Passi et al, 2008), Chinese (Cantonese) (Kam et al, 2009), French (GhulyanBe´dikian et al, 2010), Hebrew (Oron, et al, 2011), Japanese (Oishi et al, 2011), Persian (Mahmoudian et al, 2011), Tamil (Ramkumar and Swaminathan, 2011), Chinese (Mandarin) (Meng et al, 2012), and Thai (Limviriyakul and Supavanich, 2012). The THI also has demonstrated clinical utility for evaluating treatment effects when used with its companion questionnaires, namely the Hearing Handicap Inventory for the Elderly (HHIE; Ventry and Weinstein, 1982), Hearing Handicap Inventory for Adults (HHIA; Newman et al, 1990), and the Dizziness Handicap Inventory (DHI; Jacobson and Newman, 1990). For example, the battery of tinnitus, hearing, and dizziness questionnaires has been used in combination to quantify treatment-related effects for Meńie`re’s disease (Kinney et al, 1997; Storper et al, 1998; Moody-Antonio and House, 2003; Gardunõ-Anaya et al, 2005) and idiopathic sudden hearing loss (Slattery et al, 2005). Further, the coupling of the HHIE/A with the THI may be helpful from a clinical perspective in determining (1) whether it is the patient’s hearing loss or tinnitus that is causing the most difficulty (2) and selecting the most appropriate sound therapy option in the management of tinnitus. For example, if the patient’s hearing loss has little or no impact as indicated by a score of less than 18 points (out of a total of 100) on the HHIE/A, the use of sound generators may be an appropriate option. In contrast, if the HHIE/A reveals a more significant effect on the patient’s lifestyle, the use of hearing aids or combination devices (hearing aids and sound generators housed in the same device) may provide greater benefit by improving communication function and promoting tinnitus relief. These treatment effects could then be monitored efficiently using both the HHIE/A and THI in combination.



An alternative measure, namely the TFI (Meikle et al, 2012), holds great promise as an outcome measure in that it has documented validity both for scaling the severity and negative impact of tinnitus as well as for measuring treatment-related changes (responsiveness) to tinnitus intervention (AHRQ, 2012). The psychometrically robust TFI was developed by a team of 17 tinnitus researchers and clinicians. It is comprised of 25 items with eight subscales (based on factor analytic techniques): Intrusive; Sense of Control; Cognitive; Sleep; Auditory; Relaxation, Quality of Life; and Emotional. As shown in Table 4, the TFI yielded adequate reliability and validity. More importantly with regard to outcomes assessment, the TFI is the only self-report tinnitus questionnaire developed specifically to evaluate responsiveness, evaluated by computing effect sizes for responses at treatment follow-up. More specifically, for the total TFI scale, large effect sizes were demonstrated at both 3 mo (1.01, for “much or moderately improved” and 0.74 for “slightly improved”) and 6 mo (1.88 for “much or moderately improved” and 1.19 for “slightly improved”) follow-up visits (mixed treatment design). In addition, the authors indicated that a reduction of 13 points of the overall TFI score should be used as the criterion for a meaningful reduction in TFI outcome scores. Dimension-Specific Measures Dimension-specific tools evaluate only one specific aspect of health status. The principal advantage of dimension-specific questionnaire is that it offers a more detailed assessment in an area of concern over short summary scales or even longer disease/condition-specific questionnaires. In regard to problems associated with tinnitus, tools evaluating psychological well-being and sleep are of particular interest. The 14-item Hospital Anxiety and Depression Scale (HADS; Zigmond and Snaith, 1983) used to evaluate anxiety (7 items) and depression (7 items) was evaluated in a sample of patients with the primary complaint of tinnitus (Zo¨ger et al, 2004). Each item is scored using a 0–3 Likert scale, with scores ranging from 0–21 points. Based on receiver operating characteristic analyses, the authors indicated that the HADS was better at detecting depression than anxiety disorders in patients with tinnitus. Moreover, the optimal cutoff score for each subscale was #5 when anxiety and depression are being screened in the tinnitus assessment. The Beck Depression Inventory (BDI; Beck et al, 1961) is one of the most widely used self-report instruments for measuring the severity of depression both by clinicians and researchers. The 21-item questionnaire evaluates symptoms of depression including hopelessness, irritability, cognitions such as guilt or feelings

of being punished, and physical symptoms such as fatigue and weight loss. The BDI has been used in a number of tinnitus treatment studies including investigations of sound therapy (Andersson et al, 2002; Folmer and Carroll, 2006); comprehensive tinnitus management programs including audiological, psychologic, and medical treatment (Folmer, 2002); drug therapy (Johnson et al, 1993; Robinson et al, 2005; Robinson, 2007); repetitive transcranial magnetic stimulation (Frank et al, 2010); biofeedback (Haralambous et al, 1987); hypnosis (Kaye et al, 1994); and electrical cortical stimulation (Friedland et al, 2007). The Patient Health Questionnaire-9 (PHQ-9; Kroenke et al, 2001) and the Generalized Anxiety Disorder-7 (GAD-7; Spitzer et al, 2006) are short questionnaires that are used to quickly assess a patient’s emotional response to tinnitus. Responses to these questionnaires may alert a clinician that referral to a mental health care provider is warranted. Further, The PHQ-9 and/or GAD-7 could be used to help evaluate the discriminant validity of a tinnitus questionnaire. Sleep disturbance is ranked as one of the highest complaints among tinnitus sufferers (Tyler and Baker, 1983; McKenna and Daniel, 2006) causing significant distress (Axelsson and Ringdahl, 1989; Hallam, 1996; Folmer and Griest, 2000). In this connection, a variety of treatment protocols addressing insomnia have been developed including the provision of sleep education (e.g., sleep stages), relaxation therapy, cognitive therapy, and sleep hygiene (e.g., diet, sleep routines, use of sound in the bedroom, clock watching). The use of dimension-specific measures for sleep, such as the Pittsburgh Sleep Quality Index (PSQI; Buysse et al, 1989) has clinical utility in determining treatment-related effects for sleep quality. For example, Megwalu et al (2006) administered the PSQI in an open label study of 24 patients with tinnitus and sleep disturbance before and after treatment (8 wk interval from baseline to PSQI readministration) with 3 mg of melatonin (a hormone or supplement known to regulate the sleepwake cycle). A significant decrease on the PSQI was observed suggesting that melatonin was associated with improvement in sleep for the tinnitus sufferers. Handscomb (2006) also used the PSQI to assess sleep quality following the use of bedside sound generators. Changes in the PSQI scores indicated improved sleep quality for the majority of the patients who used these devices during the study. Generic Instruments Generic instruments are health profiles broad in scope, intended to capture a wide range of HRQoL issues. Although generic instruments apply to a variety of patient populations, they may be unresponsive to treatment changes for a specific condition such as


Medical Pharmacological

Treatment modality

To determine whether melatonin would result in a decrease in or resolution of tinnitus in a randomized, prospective, double-blind, placebo-controlled crossover trial. n 5 23

To evaluate the benefit of botulinum toxin A in the treatment of tinnitus with a prospective, double-blinded study design. n 5 30

To determine if melatonin improves tinnitus and if improvement is related to improved sleep (evaluated by the Pittsburgh Sleep Quality Index [PSQI; Buysse et al, 1989]) in a prospective open-label study. n 5 24

To assess the therapeutic benefit of gabapentin (Neurontin) for patients with idiopathic troublesome tinnitus in an 8 wk, double-blinded, randomized clinical trial. n 5 135

Stidham et al (2005)

Megwalu et al (2006)

Piccirillo et al (2007)

To determine the effectiveness of baclofen in ameliorating tinnitus in adults using a randomized double-blind placebo-controlled trial. n 5 63

Stated purpose of study and research design/sample size (n)

Rosenberg et al (1998)

Westerberg et al (1996)

Authors After 3 wk of treatment, within the baclofen group there was a marginally statistically significant improvement after intervention; however, reduction in mean THI scores was not clinically significant. No improvement was found for the placebo. Further, significant side effects (i.e., confusion, dizziness, drowsiness, gastrointestinal upset, weakness, and worsening of tinnitus) occurred in 26% of patients in the baclofen arm. After 30 days of treatment, the difference in THI scores between melatonin and placebo treatment were not statistically significant; however, patients with high THI scores and/or difficulty sleeping are most likely to benefit from treatment with melatonin. Although no pre- and posttreatment differences were found at 1 mo, a statistically significant decrease in THI scores was found at 4 mo post– botulinum toxin A injection for which the authors suggested the possibility of a delayed response in benefits of the treatment. The mean THI score decreased significantly between weeks 0 and 4 and between weeks 0 and 8. Melatonin use was associated with improvements in sleep quality and tinnitus. The authors concluded that melatonin may be a safe treatment for patients with idiopathic tinnitus, especially for those with sleep disturbance as a consequence of the tinnitus. No significant differences were found between baseline and posttreatment administrations of the THI for either the gabapentin or placebo groups.

THI outcome*

Table 5. Examples from a Broad Range of Treatment Outcome Studies Illustrating the Clinical Utility of the Tinnitus Handicap Inventory (THI)


90


Repetitive transcranial magnetic stimulation (rTMS)

Treatment modality

Table 5. Continued

To evaluate benefits of vestipitant (neurokinin-1 receptor antagonist) for tinnitus relief as a standalone treatment and in conjunction with paroxetine (selective serotonin reuptake inhibitor) in a randomized, double-blind, crossover study. n 5 24

Roberts et al (2011)

To determine if rTMS applied to the left superior temporal gyrus would decrease tinnitus complaints in veterans using a prospective, nonrandomized trial. n 5 7 To investigate immediate and long-term effects of low-frequency (1 Hz) rTMS in patients with tinnitus and normal hearing using a parallel, placebocontrolled randomized design. n 5 20

Lee et al (2008)

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To examine the effectiveness of low-frequency rTMS (2 wk) to the temporoparietal junction in patients with bothersome tinnitus using a crossover, doubleblind, randomized clinical trial. n 5 16

Khedr et al (2010)

Piccirillo et al (2011)

Marcondes et al (2010)

To compare the effect of different frequencies of rTMS (2 wk of treatment) and sham in a randomized, prospective study. n 5 66

Khedr et al (2008)

Jalali et al (2009)

To evaluate the efficacy and safety of memantine (NMDA inhibitor) in the treatment of tinnitus in a randomized, double-blind, placebo-controlled, prospective cross-over study. n 5 43 To evaluate the efficacy of alprazolam for relief of tinnitus using a cross-over, randomized, tripleblind, placebo-controlled trial. n 5 30


Figueiredo et al (2008)

Authors

Following 5 days of rTMS treatment, there was a significant reduction in THI scores as compared to sham for up to 6 mo after stimulation in patients with chronic tinnitus. Patients were followed after the last rTMS treatment at monthly intervals for 10 mo. rTMS contralateral stimulation revealed a greater reduction in THI scores in comparison to ipsilateral or left side stimulation. Daily low-frequency rTMS to the left temporoparietal junction is no more effective than placebo for patients with chronic tinnitus.

There was no significant improvement of THI scores after 3 mo of treatment with the memantine compared with placebo. Alprazolam in comparison with placebo did not result in statistically significant reductions in THI scores or perceived tinnitus loudness. Vestipitant alone or in combination with paroxetine did not yield improvements on the THI in comparison to placebo, suggesting that neither treatment regimen was effective in ameliorating tinnitus. There was a statistically significant decrease in THI scores for all treatment groups at 4 mo after treatment ended whereas no changed was observed for the sham group. Patients who had tinnitus for the longest period of time were least likely to respond to treatment. rTMS did not improve tinnitus in veterans.

THI outcome*


91

92

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Bartels et al (2007)

Friedland et al (2007)

Frank et al (2012)

Electrical stimulation

DiNardo et al (2009)

To investigate the effect of pulsed high-frequency electromagnetic therapy (30 min treatments, three times a week for 1 mo) on chronic tinnitus in a randomized, prospective, double-blind, placebocontrolled pilot study. n 5 37 To evaluate the long-term (3 and 42.5 mo after implantation) benefit of electrical stimulation of the vestibulocochlear nerve using a subcutaneously positioned pulse generator. n 5 4

To establish the efficacy of low-level laser therapy (20 min daily for 3 mo) for tinnitus in a prospective, randomized double-blind study. n 5 54

To evaluate low-power laser on the treatment of tinnitus in a randomized, prospective, doubleblind, placebo-controlled trial. n 5 49

To investigate the efficacy of theta-burst rTMS in patients with chronic tinnitus using a parallel randomized control study. n 5 22


Ghossaini et al (2004)

Teggi et al (2009)

Mirz et al (1999)

Chung et al (2012)

Authors

Electromagnetic therapy

Low-power laser

Treatment modality

Table 5. Continued

After 1 mo, THI scores were reduced in five patients (45.4%) and remained unchanged in the other six patients. Three weeks following treatment, there was no significant difference between preand postadministrations of the THI; however, inspection of individual subject data revealed 5 out of 32 patients (16%) reported a significant

Based on THI scores, the effect sizes of neurostimulation treatment at the 3 and 42.5 mo follow-ups were 0.7 (average effect size) and 1.75 (large), respectively. These findings suggest substantial responsiveness to treatment. Significant improvement on the THI was found, although objective measures of tinnitus loudness remained stable. No surgical or stimulation-related complications were observed.

THI scores were significantly lower 1 wk after treatment in comparison to the sham-stimulation group; however, after 1 mo THI score rose indicating that the positive effects of theta-burst rTMS may be temporary. There were no statistically significant differences in pre- and posttreatment THI scores for patients treated with active laser compared with those treated with placebo. No statistical differences on THI scores were detected for either the low-level later treatment or sham following treatment. There were no significant differences between pre- and posttreatment scores for either the treatment or placebo groups.

THI outcome*


Sound therapy Hearing aids

Alternative therapies

Treatment modality

Table 5. Continued

To investigate whether TRT with open ear hearing aids is as efficacious as sound generators using a randomized prospective parallel-group designed. n 5 91

Parazzini et al 2011

To assess the effect of ginko biloba and clonazepam (GABA-receptor agonist) on tinnitus in an open-label, randomized, crossover study. n 5 11

Han et al (2012)

To assess the effects of hearing aids on the perception of tinnitus. n 5 34

To investigate the long-term effects of acupuncture for treatment of tinnitus using a randomized, single-blind placebo-controlled pilot study. n 5 33

Jeon et al (2012)

Surr et al (1999)

To explore patient’s perceptions of outcome from acupuncture. A series of six n 5 1 (single subject design) controlled trials for patients with tinnitus was used.

To ascertain if ginko biloba benefits patients with tinnitus using a randomized placebo-controlled double-blind trial and meta-analysis of randomized trials. n 5 66 adult patients with tinnitus


Jackson et al (2006)

Rejali et al (2004)

Authors

Hearing aid use in new users after 6 wk showed statistically reduced THI scores, but typically the effect was small. Authors concluded, however, that the THI is a useful clinical tool in contributing to the overall profile of hearing aid benefit in new users with tinnitus. THI data revealed statistically significant improvements in both treatment groups at 3, 6, and 12 mo post–baseline measurement. Authors concluded that

reduction on the THI (defined as a minimum change of 7 points). After 3 mo, there was no significant difference for the ginko biloba or placebo between pre- and posttreatment. Further, a meta-analysis of five additional studies meeting inclusion criterion failed to yield evidence that ginko biloba provides benefit for patients with tinnitus. Authors reported that after treatment there is a tendency for a decrease in THI scores, although four subjects showed “little change” following treatment. THI showed significant reduction in scores at the end of treatment (5 wk), which was sustained at 3 mo after treatment for the acupuncture group. No significant differences pre-and posttreatment were observed for the sham-acupuncture group. Before and after treatment, THI scores showed a significant reduction for the clonzepam, whereas there was no difference for the ginkgo biloba.

THI outcome*



93

Cochlear implantation

Tinnitus retraining therapy (TRT)/ habituation/tinnitus masking (TM)

Treatment modality

Table 5. Continued

94

Delivered by Ingenta to: University of Massachusetts - Amherst IP : 128.119.168.112 On: Wed, 03 Sep 2014 15:48:38 To evaluate the effect of cochlear implantation on tinnitus evolution using a nonrandomized prospective study design. n 5 30

To confirm which tinnitus factors (e.g., age, gender, duration of tinnitus, hearing level, tinnitus pitch/ loudness, and THI score) influence the results of TRT. n 5 53

Koizumi et al (2009)

DiNardo et al (2007)

To evaluate the clinical efficacy of TRT and TM in a sample of veterans with severe tinnitus using a prospective quasi-randomized controlled trial. n 5 123

To demonstrate the efficacy of TRT for tinnitus relief compared to a waiting list group and partially treated group using a prospective nonrandomized clinical design. n 5 158

Herraiz et al (2005)

Henry et al (2006)

To determine the therapeutic efficacy of TRT in a nonrandomized prospective study. n 5 32


Berry et al (2002)

Authors tinnitus treatment was equally effective for sound generators and hearing aids. Following 6 mo of TRT, the total, emotional, functional, and catastrophic THI scores yielded significant improvements. THI showed a statistically significant improvement at 6 and 12 mo after the initiation of treatment compared with the control group. Sixty-eight percent of patients yielded a THI score difference of $20 points following 1 yr of treatment. Based on effect size calculations, both TRT and TM demonstrated improvement in perceived tinnitus handicap. TM effects remained constant over time while TRT effects improved incrementally. For the most severe patients (e.g., “very big problem”), TM provided the greatest improvement at 3 mo with comparable improvements at 6 mo. Improvement for TRT over TM was greater at 12 mo and yielded further gains at 18 mo, demonstrating greater long-term functional benefits. Tinnitus loudness and THI scores were related to the therapeutic effect of TRT. Initial THI scores $50 points showed greater decreases on the THI total score than scores ,50 pre-TRT. The authors concluded that TRT is more effective in patients with greater perceived tinnitus handicap and should be used as a tool for screening patients with tinnitus After 6 mo of implantation, a comparison between pre- and postimplant THI scores using a multicategory classification severity scheme showed

THI outcome*


Neuromonics Tinnitus Treatment (NTT)

Treatment modality

Table 5. Continued

Delivered by Ingenta to: University of Massachusetts - Amherst IP : 128.119.168.112 On: Wed, 03 Sep 2014 15:48:38 To evaluate the efficacy of the NTT over a 2 yr period (baseline, 2, 4, 6, 12, 24 mo) in patients with chronic tinnitus in a multi-institutional prospective study. n 5 52

To assess the effects of cochlear implants on the perception of tinnitus using the THI in a prospective, longitudinal study. n 5 142

To evaluate the effects of unilateral cochlear implants on bilaterally perceived tinnitus in a prospective study. n 5 41


Newman and Sandridge (2012) To determine perceived benefit and economic value between sound generators (SGs) and NTT using a retrospective between-subject clinical study. n 5 56

Wazen et al (2011)

Amoodi et al (2011)

Quaranta et al (2008)

Authors

decreased scores in 65% of the cases, unchanged scores in 30%, and increased scores in 5%. On average, postimplantation THI scores showed a statistically significant decrease. At least 3 mo after activation, there was a statistically significant reduction on the total and subscale THI scores. Two patients reported catastrophic THI scores after implantation. One patient presented with a preoperative score of 84 and postoperative score of 84; however, the other patient reported an initial score of 18 that increased to 78 following implantation. Twelve months postimplantation revealed statistically significant reductions on the THI total and subscale scores. The greatest improvement in tinnitus handicap was observed for patients demonstrating moderate to severe perceived handicap pre-implantation on the THI. Changes in THI scores were correlated with the Medical Outcomes Study Short Form 36 (SF-36) role limitations subscale (social functioning, emotional functioning, and general health). A statistically and clinically significant difference ($20 point decrease) was detected for the 6, 12, and 24 mo follow-up intervals. The THI showed the greatest improvements at 1 yr following baseline evaluation. THI scores revealed a statistically significant improvement for both forms of sound therapy between baseline and 6 mo postfitting; cost-effectiveness analysis (CEA) and cost-utility analysis (CUA), using the THI as the measure of perceived tinnitus benefit, suggested

THI outcome*


95

96

Delivered by Ingenta to: University of Massachusetts - Amherst IP : 128.119.168.112 On: Wed, 03 Sep 2014 15:48:38 Kaldo et al (2008)

Herraiz et al (2007)

Lipman and Lipman (2007)

Authors

Acceptance and commitment therapy (ACT) Hesser et al (2009)

Psychological/behavioral treatments Cognitive behavioral therapy (CBT)

Alternative sound therapies

Treatment modality

Table 5. Continued

To investigate the processes of change in reducing the negative impacts of tinnitus during and after the completion of ACT. n 5 19

To compare the efficacy of Internet-administered CBT self-help treatment for tinnitus distress with a traditional CBT face-to-face group treatment using a randomized controlled trial. n 5 51

To evaluate the benefits of auditory discrimination training (ADT) (procedure designed to increase cortical areas responding to trained frequencies [i.e., damaged cochlear areas with cortical misrepresentation] and to shrink neighboring overrepresented ones [i.e., tinnitus pitch] in a prospective controlled descriptive study in patients with high-frequency tinnitus). n 5 27

To evaluate the effectiveness of a phase-shift treatment (sound cancellation by using the patient’s tinnitus frequency to induce residual inhibition) for predominant tonal tinnitus in a single-blinded crossover study. n 5 61


Approximately 3 wk and 1 yr following both forms of CBT treatment, significant improvements on the THI were observed. There were no significant interactions between treatment modalities from posttreatment to follow-up. The authors suggested that the Internet method of providing CBT may be of practical benefit in that it was cost-effective and offered patients greater access to treatment. There a significant THI difference score between baseline and 6 mo follow-up, with a large within group effect size (Cohen’s d 5 .91). Although there was no significant difference between pretreatment and 2 wk following initiation of ACT, reductions in tinnitus

that the SGs may be more cost-effective in comparisons to NTT; however, the magnitude of economic value is dependent upon initial THI scores. Following 1 mo of treatment (2 wk of active treatment; 2 wk of placebo), 27% yielded a $20 point reduction on the THI. Using a graded severity classification system (slight, mild, moderate, severe, catastrophic handicap), 37% showed a decrease of one THI grade, 5% decreased by two THI grades, and 3% of patients increase by one THI grade. On average, THI scores decreased from 26.2 to 21.6%. The authors indicated that this was a statistically significant improvement; however, this reduction is not clinically significant.

THI outcome*


Westin et al (2011)

To evaluate the immediate effects of ACT in comparison to a wait list group and to compare the long-term effects of ACT with those of TRT across a period of 18 mo using a randomized prospective design. n 5 62

handicap occurred as early as 4 wk after the beginning of therapy. THI results suggested that ACT is more effective in reducing perceived tinnitus handicap in comparison to TRT or being on a wait list. ACT showed large immediate effect sizes at 10 wk, which were sustained at 6 and 18 mo.

*Many of the above-cited studies used additional disease-specific outcome measures (e.g., Tinnitus Handicap Questionnaire; Tinnitus Reaction Questionnaire), visual analog scales, and psychoacoustic tests (e.g., pitch and loudness matching; minimal masking level) to quantify treatment-related changes; however, only data from the THI are reported for illustrative purposes.

Treatment modality

Table 5. Continued

Authors


THI outcome*


tinnitus because they have fewer (if any) items relevant to the condition under study (Guyatt et al, 1993). To test this hypothesis, El Refaie et al (2004) administered the Medical Outcomes Study Short Form 36 (SF-36) health survey to a sample of patients who had attended and had been discharged from the Nottingham Tinnitus Clinic (NTC). The NTC used a patient-centered tinnitus management approach of counseling, relaxation therapy, and sound therapy. The SF-36 (Ware and Sherbourne, 1992) is a widely used multi-item global assessment of patient function that evaluates eight health domains including physical functioning (10 items), role limitation due to physical problems (four items), social functioning (two items), bodily pain (two items), general mental health (five items), role limitations due to emotional problems (three items), vitality (four items), and general health perceptions. El Refaie and colleagues (2004) reported that scores on the physical health and mental health scales improved significantly following NTC attendance and treatment. The authors concluded that the patients demonstrated significantly greater health utility after attending the NTC, providing evidence to support the benefit of tinnitus rehabilitation as measured by the SF-36. Further, they suggested that the SF-36 should be considered a robust and useful tool for assessing tinnitus intervention outcomes. ASSESSING ECONOMIC VALUATION OF TREATMENT OUTCOME

I

n this era of evidence-based practice, cost-containment, and shrinking health-care dollars, both clinically and fiscally responsible health-care practices are important to patients, providers, third-party payers, and policy makers. Accordingly, tinnitus treatment approaches should be developed not only to demonstrate reductions in activity limitation/ participation restriction but should also yield economic value. That is, econometric methods (Streiner and Norman, 1994; Gold et al, 1996) designed to evaluate cost/benefit are becoming increasingly more important given today’s health-care and economic environment. Although limited data are available about the costeffectiveness of otologic/audiological hearing device technology (Mulrow et al, 1990; Wyatt et al, 1996; Newman and Sandridge, 1998; Cheng and Niparko, 1999; Summerfield et al, 2002; Joore et al, 2003; Snik et al, 2006) and clinical programs (Abrams et al, 2002; Carroll and Downs, 2006), even fewer studies have been directed toward the economic valuation of tinnitus treatment (Tyler, 2012). In an exploratory study, Newman and Sandridge (2012) applied a cost-effectiveness analysis (CEA) and cost-utility analysis (CUA) to capture the



Table 6. Formulas Used to Calculate the CostEffectiveness of Alternative Sound Therapy Options (Sound Generators [SGs] versus Neuromonics Tinnitus Treatment [NTT]) Cost calculation: Incremental cost of treatment 5 IC Variables: •Total cost of SGs (i.e., cost of devices and follow-up services) 5 TC1 •Total cost of NTT (i.e., cost of device and follow-up services) 5 TC2 Formula: IC 5 TC1 – TC2 Effectiveness calculation: Incremental effectiveness of treatment (i.e., benefit of sound therapy determined by Tinnitus Handicap Inventory [THI] pre-/postfitting difference score) 5 IE Variables: •Total effectiveness of SGs (i.e., benefit based on improvements in THI score) 5 E1 •Total effectiveness of NTT (i.e., benefit based on improvements in THI score) 5 E2 Formula: IE 5 E1 – E2 Cost-effectiveness calculation: Cost-effectiveness ratio 5 C/E Variables: •Incremental cost of treatment (see above) 5 IC •Incremental effectiveness of treatment (see above) 5 IE Formula: C/E 5 IC/IE Source: Adapted from Gold et al (1996) and Newman and Sandridge (2012).

economic outcome of two sound therapy options currently used in clinical practice, namely ear-level broadband sound generators (SGs) and Neuromonics Tinnitus Treatment (NTT). CEA examines the incremental cost per unit of benefit on a standardized outcome measure (THI in the current example) that is achieved from choosing one treatment option over another. In contrast, CUA captures the cost per quality of life units gained expressed as quality-adjusted life years (QALY) (Detsky and Laupacis, 2007; Hnath Chisolm and Abrams, 2008). Accordingly, QALY is a measure of both the quality and quantity of life lived in relation to a particular disease/ condition burden (e.g., tinnitus). As shown in Table 6, CEA evaluates three separate treatment comparisons (Gold et al, 1996; Newman and Sandridge, 2012): total treatment cost; treatment effectiveness; and cost-effectiveness ratio (C/E) between the two sound therapy options. The C/E ratio reflects which treatment approach produces the greatest benefit for a given expenditure. CUA incorporates quality of outcome (i.e., treatment benefit) and survival information to determine the cost

per QALY gained (Abrams et al, 2002; Hnath Chisolm and Abrams, 2008). In this formula, adapted from Hnath Chisolm and Abrams (2008), cost of treatment includes retail price of device including follow-up services; obtained benefit is derived from pre-/posttreatment THI difference scores; and life expectancy is obtained from an actuarial table: Cost per QALY gained ¼

Cost of treatment ðObtained benefit 3 Life expectancyÞ

As shown in Figure 4, Newman and Sandridge (2012) found that SGs and NTT demonstrated statistically significant ( p , 0.001) reductions (i.e., improved benefit) on the THI between baseline and 6 mo posttreatment administrations of the THI. Yet CEA and CUA suggested that SGs were a more cost-effective treatment option, especially for patients with higher initial THI scores. Specifically, CEA showed that for the SGs, the cost per unit of improvement (treatment utility) on the 100-point THI was $74 per point whereas the cost for NTT was $189 per point. Moreover, CUA revealed that the overall SG option cost $604 per QALY gained, whereas NTT cost $1171 per QALY gained. In short, the CEA and CUA suggest that SGs appear to be just as effective as NTT while being less expensive to the end user. The observed aforementioned economic analyses may be helpful in assisting clinicians and patients in making a more informed decision about valuation of treatment in relation to expected outcomes; however, they should not and cannot be used in isolation (Newman and Sandridge, 2012). For example, when selecting a sound therapy option for a particular patient, a number of individualized, patient-centered factors need to be

Figure 4. Total scores on the Tinnitus Handicap Inventory (THI; Newman et al, 1996) comparing sound generators (SGs) to the Neuromonics Tinnitus Treatment (NTT) at baseline and 6 mo follow-up. Adapted from Newman and Sandridge (2012).



taken into account including the patient’s lifestyle; manual dexterity; sound stimuli acceptability (e.g., broadband noise versus music versus environmental sounds); cosmetics and sound stimulus delivery hardware/ technology (e.g., ear level devices; body worn devices; use of “apps” on personal music player/Smartphone); daily dosage of auditory stimuli (e.g., hours/day usage recommendations); and personal finances. Despite this host of cautionary variables, economic valuation of tinnitus treatment options should be pursued as it remains critical that clinicians justify the value of recommending one type of intervention option over another in relation to observed benefit. FUTURE DIRECTIONS AND CONCLUSIONS

C

urrently, the need still exists to develop an optimal test battery strategy that is both efficient and responsive to treatment-related change. A combination approach using a standardized methodology for obtaining the psychoacoustic attributes of tinnitus coupled with a disease-specific and generic measure would provide complementary evidence underlying the assessment of tinnitus impairment, activity limitation, and participation restriction. Using such a standardized core set of outcome measures allows for comparison of efficacy data across centers; clinical audits and the demands of managed health care; improved communication among clinical providers and scientists; and standardization of national and international epidemiological studies (Goldstein, 1997; Langguth, Kleinjung, et al, 2011).

Psychoacoustic measurement of tinnitus loudness would be especially beneficial for quantifying fastacting treatments (e.g., deep brain stimulation; intratympanic steroid injections). This is in contrast to questionnaires evaluating the psychosocial HRQoL consequences of tinnitus where a longer time interval is necessary to demonstrate patterns of change in everyday life activities (Meikle et al, 2008). Disease-specific tools are responsive to the effects of slow-acting treatments (e.g., cognitive-behavioral therapy) (Meikle et al, 2008) and produce evidence most relevant to the clinician (Fitzpatrick et al, 1998). A generic measure may provide information important to the policy community (e.g., evaluating interventions across different disease groups) and may reveal unexpected (both positive and negative) treatment effects of novel intervention strategies (Fitzpatrick et al, 1998). Accordingly, an outcomes assessment battery provides a range of data, evaluating a number of constructs underlying the sensory and functional consequences associated with the tinnitus experience. In an effort to develop a protocol for patient assessment and outcome measurement, a group of researchers and clinicians at a Tinnitus Research Initiative (TRI) meeting proposed a set of recommended instruments to be used in clinical trials (Langguth et al, 2007). With a standardized set of tools, it would be possible to make comparisons between studies conducted at different research centers around the world. A universally accepted outcomes battery would help promote evidence-based practice by facilitating completion of quantitative systematic reviewers, including the use of meta-analyses

Table 7. Recommended Outcome Measurements Based on Consensus Statement from the Tinnitus Research Initiative (TRI) Meeting (Langguth et al, 2007) Recommendation

Category

A

Validated questionnaire designed to assess tinnitus severity

B C C C

Assessment of tinnitus severity by additional measures Assessment of depressive symptoms Assessment of anxiety Assessment of quality of life

C C C C

Assessment of insomnia Assessment of loudness Assessment of maskability Objective measurement of brain function

Examples Tinnitus Handicap Inventory (THI; Newman et al, 1996), Tinnitus Handicap Questionnaire (THQ; Kuk et al, 1990), Tinnitus Reaction Questionnaire (TRQ; Wilson et al, 1991), Tinnitus Questionnaire (TQ; Hallam et al, 1988), Tinnitus Functional Index* (TFI; Meikle et al, 2012) THI recommended because of its availability in most languages Beck Depression Inventory (BDI; Beck et al, 1961) State-Trait Inventory (STAI; Spielberger et al, 1970) WHO Disability Assessment Schedule (WHO-DAS II; McArdle et al, 2005) Pittsburgh Sleep Quality Index (PSQI; Buysse et al, 1989) Psychoacoustic loudness-matching Psychoacoustic measurement of minimum masking level (MML) Functional imaging, electrophysiology

Note: A = essential recommendation; B = highly recommended; C = might be of interest. *TFI was not developed at the time of the TRI meeting; however, due to its robust psychoacoustic characteristics, including responsiveness (effect size), it should be considered as a primary tinnitus outcome measurement tool.



that allow for a more precise estimate of treatment effects (Chisolm et al, 2007). Table 7 summarizes the recommendations resulting from the TRI workshop regarding outcomes measurement. It is noteworthy that the consensus recommendations indicated that “in the future a better and more widely validated questionnaire was required to assess treatment-related outcomes.” To this end, the newly developed TFI (Meikle et al, 2012) serves as an appropriate instrument to add to the TRI recommended battery as it was specifically designed to evaluate responsiveness. If the TFI is used as a primary outcome measure for worldwide application, it will have to be subjected to appropriate methodologies (e.g., use of independent translations of the questionnaire that are compared against each other, backward translations, test of acceptability to respondents) to ensure high standards of questionnaire translation (Leplege and Verdier, 1995; Fitzpatrick et al, 1998). In addition to the use of standardized outcome measures, there is a strong need to apply more rigorous study designs when attempting to assess treatmentrelated change. For example, before-after designs where changes are measured at only two points in time (i.e., at baseline and at the end of treatment) provide limited information about performance stability and change in comparison to studies where performance is measured at multiple time intervals (i.e., baseline, during treatment, completion of treatment). Even with multiple assessments, it may be difficult to evaluate long-term changes in tinnitus and maintenance of the desired treatment effect (e.g., habituation of the tinnitus sensation). Moreover, many tinnitus protocols use combined approaches of counseling and treatment (e.g., sound therapy coupled with counseling), complicating the process of extracting evidence for or against the intervention strategy. In this connection, McKenna and Irwin (2008) have questioned the isolated benefits of sound therapy alone when psychologic counseling is used in the rehabilitation process. Accordingly, the singular effects of sound therapy distinguishable from counseling have not been adequately addressed (Hobson et al, 2010). In order to more fully understand tinnitus treatment benefits, it is imperative that future outcomes studies employ more rigorous designs and contain, minimally, the following characteristics: utilization of randomized control group(s) and blinding; appropriate statistical testing including “dropouts” that should be used in an “intention to treat” analysis rather than elimination from the final data set; long-term follow-up assessment to evaluate stability of treatment; use of validated outcome measures designed specifically to evaluate responsiveness; appropriate inclusion criteria to avoid “ceiling” and “floor” effects; and appropriate sample sizes based on a power analysis (Dobie, 2004; Newman and Sandridge, 2009).

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