Clinical Research
Improvement in Oral Health–related Quality of Life after Endodontic Treatment: A Prospective Longitudinal Study Pei Liu, BDS, MDS (Endo), PhD,* Colman McGrath, BA, BDentSci, DDPHRCS, MSc, FDSRCS, FFDRCSI, FFPH, MEd, PhD,*† and Gary Shun Pan Cheung, BDS, MSc, MDS, PhD, FCDSHK (Endo), FHKAM, FAMS, FRACDS, MRACDS (Endo)‡ Abstract Introduction: To date, evidence of the effectiveness of endodontic treatment and criteria of success have mainly been considered in terms of clinical outcome, and there is a lack of information of treatment outcomes from patients’ perspectives. This study aimed to assess changes in quality of life after endodontic treatment and to determine if changes in quality of life were associated with changes in patient-perceived oral health and clinical assessments of success. Methods: This longitudinal study involved 279 subjects. Patient-reported outcome measures based on oral health–related quality of life was assessed using the short form of the Oral Health Impact Profile (OHIP-14). The patients completed the assessments before endodontic treatment and 1 month and 6 months after root canal obturation. A global oral health transition assessment was ascertained by a single (global) item rating of oral health improvement and clinical assessment mainly based on the Periapical Index (PAI) of periapical radiographs. Results: There were significant changes in OHIP-14 scores over the study period after conventional orthograde endodontic treatment (from pretreatment–6 months postobturation) (P < .001). The magnitude of statistical change (effect size) was moderate (0.61) in the short-term (after 1 month) and large (0.71) in the longer-term (after 6 months). Changes in the OHIP-14 was associated with changes in patient self-rating oral health status (P < .001), which was also associated with changes in PAI scores (P < .05). Conclusions: Endodontic treatment improves quality of life. The OHIP-14 measure is both sensitive and responsive to endodontic treatment and is likely to be useful in understanding patients’ perspectives of outcomes from endodontic care. (J Endod 2014;-:1–6)
Key Words Longitudinal study, Oral Health Impact Profile, oral health, root canal therapy
E
ndodontic problems (with clinical evidence of pulp and/or periapical tissue problems) are common and key reasons why patients seek dental care (1, 2). Underpinning the demand for endodontic treatment is the growing recognition that endodontic problems have an impact on quality of life (3–5). Moreover, it is recognized that tooth loss is associated with impairment of quality of life and that the location and distribution of tooth loss affect the severity of impairment (6). Thus, retaining teeth whenever possible is important, and when the pulp and periapical tissues are affected, this typically requires endodontic treatment (7). To date, evidence of the effectiveness of endodontic treatment and criteria of success have largely been considered in terms of clinical outcome. Survival of teeth (at least in the short-term) is very high, and success rates based on strict radiographic criteria range from 30% to over 90% (8, 9). However, clinical parameters alone provide a limited understanding of oral health outcomes. There has been a paradigm shift in health care (including oral health care) to patient-reported outcomes of treatment and services (10, 11). Within the endodontic context, there has been limited study of patientreported outcomes aside from pain (12). This in part relates to the fact that although standardized (valid and reliable) measures of oral health–related quality of life (OHQoL) exist, there is scant evidence of the appropriateness of these measures to discriminate between patients with and without endodontic problems (5). Moreover, if patient-reported outcomes/quality of life measures are to be used to assess the outcome of endodontic care, it is important first to determine if the measures are sensitive to treatment (ie, their scores change [improve] after treatment, a concept referred to as ‘‘sensitivity’’) (13). Second, changes in scores should correspond with actual improvements in oral health (either clinical or subjective), a concept referred to as ‘‘responsiveness’’ (14). This study aimed to determine the sensitivity and responsiveness of a commonly used OHQoL measure with respect to orthograde endodontic treatment among adults presenting with pulp and/or periapical tissue problems.
From *Periodontology and Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China; †Center of Stomatology, The Second People’s Hospital of Shenzhen, The First Affiliated Hospital of Shenzhen University, Shenzhen, China; and ‡Comprehensive Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China. Address requests for reprints to Prof Colman McGrath, Periodontology and Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2014 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2014.02.008
JOE — Volume -, Number -, - 2014
Improvement in OHQoL after Endodontic Treatment
1
Clinical Research Materials and Methods Sample This prospective longitudinal study recruited subjects referred to the discipline of comprehensive dental care at a university teaching hospital in Southern China. The inclusion criteria of this study were as follows: 1. Patients with clinical evidence of pulp and/or periapical tissue problems deemed to require root canal therapy 2. Adults 18 years and older 3. Patients of Chinese ethnicity 4. Patients who could read traditional Chinese The exclusion criteria applied were as follows: 1. Patients with serious medical conditions for which they were hospitalized in the past year and/or taking medication for their condition that required consultation with a physician before dental treatment 2. Patients with physical disabilities 3. Patients with communication difficulties noted on their record In determining the sample size requirement, a reference was made to a case-control study of OHQoL among subjects requiring endodontic treatment versus a control group in periodontal maintenance (5). The case-control study identified that there was a 41% difference in the short form of the Oral Health Impact Profile (OHIP-14) scores between the case and control subjects. On the basis that after endodontic treatment subjects’ quality of life would be at least as good as the controls (and most likely better because the control sample was composed of periodontal maintenance patients), it was anticipated that there would be a 50% improvement in OHIP-14 scores. In setting a 5% significance level and 80% power for a pretreatment group with an OHIP-14 score of 13.9 (standard deviation = 9.9) and a 6-month post-treatment score of 6.9 (50% reduction), a sample size of 189 was estimated. Considering a potential dropout rate of 25% over the 6-month period, recruitment of 250 subjects into the study was planned. This patient-centered study was approved by the local institutional review board (HKU/HA HKW IRB UW 07-1177).
Data Collection Patient-reported Outcome Measures. Patients’ OHQoL was assessed by using 1 of the most sophisticated and widely used measures—the OHIP-14 (15). The OHIP-14 consists of 14 questions arranged over 7 domains (physical functioning, physical pain, physiological disability, physical disability, psychological disability, social disability, and handicap) based on the World Health Organization’s theoretic model of disease-impairmentdisability-handicap adapted for oral health by Locker (16). A cultural and linguistically valid and reliable version of the OHIP-14 was used (17). Patients self-completed assessments per treatment, at the 1-month review, and at the 6-month review. A global oral health transition assessment was ascertained by a single (global) item rating of oral health improvement on a 5-point Likert scale with responses ranging from ‘‘much better,’’ ‘‘somewhat better,’’ ‘‘no different,’’ ‘‘somewhat worse,’’ to ‘‘much worse’’ at the 6month review appointment (14). Information on sociodemographics was also collected, including age (in years), sex, formal educational attainment level (highest level attained: no formal/primary school, secondary school, or college/ university education), and personal monthly income level (Hong Kong dollars) (HK $0–$9999/month, HK $10,000–$19,999, HK $20,000–$29,999, or HK $30,000 or above [$1 US = $7.8 HK]). 2
Liu et al.
Clinical Assessments. Periapical radiographs obtained pretreatment and at the 6-month review appointment were rated according to the PAI system by a trained and calibrated examiner blind to the subjective patient reports (18). A radiograph with a PAI score of $3 can be classified as having periapical radiolucency. To assess intrarater agreement during the study, 10% of the radiographs were re-scored blind of the initial assessment. The kappa value for agreement of PAI score >3 was 0.87. Data Analyses The profile of those who completed the study compared with those who were initially recruited into the study (baseline subjects) was undertaken to determine any nonresponse bias using the chi-square statistical test for categoric data and the Mann-Whitney U test for continuous variables. Nonparametric analysis methods were adopted in exploring changes in quality of life as a result of endodontic treatment because the quality of life data were determined using Poisson distributions. Friedman 2-way analysis of variance (ANOVA) was used to compare the relative changes in quality of life scores at baseline, at the 1-month postobturation review visit, and at the 6-month postobturation review visit. To identify if there were significant changes in quality of life between the different assessments points (ie, baseline–1 month, baseline–6 months, and 1–6 months), the Wilcoxon signed rank test, a nonparametric test equivalent to the paired t test, was used. The magnitude of the statistical difference was determined between each time period by a nonparametric method of effect size (ES) (19) calculation. In this case (unlike a case-control or cross-section study), ES equals the mean difference between 2 independent groups/standard deviation of the baseline data. The global oral health transitional ratings of oral health was categorized into 3 groups to aid in statistical analysis because of the small numbers in the ‘‘worse’’ categories: Much better = 2 Somewhat better = 1 No different/worse = 0 PAI changes between baseline and the 6-month postobturation review visit were categorized as follows: No change = 0 PAI score change of 1 = 1 PAI score change of 2 = 2 Subsequently, the associations between changes in oral health (clinical: PAI score change and patient perceived: global ratings of improvement in oral health) and changes in OHIP-14 scores at the 6-month review were explored using Kruskal-Wallis 1-way ANOVA (nonparametric version of 1-way ANOVA). In addition, the gradient of changes in quality of life scores was examined relative to the gradient of improvement in oral health to provide information on the responsiveness of the quality of life measures.
Results Response Rate and Profile of the Group A consecutive sample of 279 patients with endodontic disease met with the inclusion and exclusion criteria, and 213 (76.3%) completed OHQoL assessments at all 3 time points (Fig. 1). There was no significant difference in the sociodemographic status or clinical oral health status of those who completed the study versus those recruited as baseline (Table 1). JOE — Volume -, Number -, - 2014
Clinical Research
Figure 1. A flow diagram of patient participation in the longitudinal study.
Sensitivity There was a significant difference in the OHIP-14 summary scores over time (P < .001). Over the 6-month period, the ES was 0.71 (Table 2). Multiple-comparison statistical tests identified a significant difference in the OHIP-14 summary scores between baseline and 1 month (P < .001, ES = 0.61) and a further significant reduction in the OHIP-14 summary scores between 1 and 6 months (P < .001, ES = 0.12). Across all 7 domains of the OHIP-14, there was a significant difference in the domain scores over time (P < .001). Over the 6-month period, the ES values ranged from 0.42 (functional limitation) to 0.77 (physical pain). Multiple-comparison statistical tests identified a significant difference in all OHIP-14 domain scores between baseline and 1 month (P < .001); the ES of domains ranged from 0.24 (functional limitation) to 0.65 (psychological discomfort). A further significant reduction in 4 of the 7 OHIP-14 domain scores between 1 and 6 months was observed (P < .05). The ES ranged from 0.10 (psychological disability) to 0.18 (physical pain) among domains that significantly changed.
JOE — Volume -, Number -, - 2014
Responsiveness At the 6-month postobturation review, 42.3% (90) of patients rated their oral health as ‘‘much better,’’ 37.6% (80) as ‘‘somewhat better,’’ and 20.2% (43) as ‘‘no different/worse.’’ There was a significant association between changes in the OHIP-14 summary scores and selfratings of improvement in oral health at the 6-month follow-up (P < .001). Furthermore, there was an observed gradient of change in the OHIP-14 summary scores with respect to perceived improvement in oral health at 6 months (Table 3). Changes in all OHIP-14 domain scores were associated with self-rating of improvements in oral health at 6 months (P < .05). There was also an observed gradient of change in the OHIP-14 domain scores with respect to perceived improvement in oral health at 6 months. Compared with baseline PAI ratings (highest value per subject), at 6 months postobturation, 27.7% (59) remained the same, 31.0% (66) decreased in PAI rating by 1, and 41.3% decreased in PAI rating by 2. There was a significant association between changes in the OHIP-14
Improvement in OHQoL after Endodontic Treatment
3
Clinical Research TABLE 1. Sociodemographic, Clinical Oral Health Status, Endodontic Characteristics, and Baseline OHQoL and HQoL Scores of the Longitudinal Study Group Sociodemographics Age, mean SD Sex, % (n) Male Female Education level, % (n) Up to primary school Secondary school Postsecondary school Declined to answer Income per month, % (n) HK $0–$9,999 HK $10,000–$19,999 HK $20,000 and above Declined to answer Clinical oral health indicators Dentition status, mean SD DMFT DT FT MT Periodontal health status, % (n) CPI score 3 1>2>3 1>2=3
0.61 0.24 0.61 0.65 0.39 0.52 0.46 0.55
0.71 0.42 0.77 0.72 0.43 0.60 0.57 0.61
0.12 0.11 0.18 0.07 0.05 0.10 0.13 0.08
P values in bold show a statistically significant difference ( 0.50) and ‘‘large’’ between pretreatment and 6 months (ie, ES > 0.70) but did not improve much between 1 and 6 months (19). It is of note that among individual domains of the OHIP the magnitude of statistical change varied considerably and over time. In this study, to establish responsiveness, 2 gold standards of successful endodontic outcomes (ie, transitional ratings of oral health and changes in PAI scores) were used as recommended when interpreting responsiveness (14). Although it is acknowledged that changes in PAI at 6 months do not provide a sufficient insight into healing/nonhealing, they do provide some insight into clinical change. Most patients did perceive that their oral health had improved, but a quarter (at 1 month) and 1 in 5 patients (at 6 months) perceived it to be no better. Nevertheless, there was an observed gradient of changes in the OHIP-14 with respect to perceived changes in oral health (although not always as expected at 1 month with respect to the OHIP-14) and with respect to PAI
changes observed at 6 months. These findings confirm the responsiveness of the measures but indicate that they are more responsive to patients’ perceptions of their oral health than the traditional clinical measure of endodontic success (ie, PAI ratings). This can be expected because subjective measures (self-reports) of oral health are not necessarily correlated or associated with clinical oral health status (23). It should be noted that no attempt was made in this study to determine what factors influence OHQoL or its changes. Clearly, there are many factors that may influence this and not merely clinical factors per se. Moreover, changes in OHQoL may be associated with oral rehabilitation (after root canal obturation), and no attempt was made to consider any individual effect; rather, we report on a group of patients’ OHQoL experiences after root canal therapy (in its broadest sense). Specific details as to tooth reduction, oral rehabilitation, and so on were not recorded, and we recognize this as a limitation of this study. Moving the research (and practice) forward, it would be of value to support or refute these claims in other settings. This in itself could help provide valuable information for informed consent for patients, audit, and evidence-based practice (11). In addition, it would be useful to determine the minimum important clinical difference that is ‘‘the subjective significant difference that is meaningful to the patients’’ (24), but this is likely to require a larger sample size and a more diverse outcome such that values for OHQoL could be determined for those with ‘‘minimal or little’’ improvement (23). Further studies are warranted to investigate the main sort of changes after endodontic treatment and the key clinical
TABLE 3. Association between Observed Changes at the 6-month Follow-up in QoL (OHIP-14) and Patients’ Global Rating of Changes or PAI Score Changes (N = 213) Global rating of change of oral health (mean ± SD) Much better (n = 90) OHIP-14 score 10.2 10.5 Functional limitation 0.8 1.5 Physical pain 1.7 2.1 Psychological discomfort 2.0 2.2 Physical disability 1.3 2.0 Psychological disability 1.7 2.0 Social disability 1.3 1.8 Handicap 1.4 1.6
PAI score change (mean ± SD)
Somewhat better No different/worse
PAI no change
PAI PAI decreased 1 decreased 2
(n = 80)
(n = 43)
P value
(n = 59)
(n = 66)
(n = 88)
P value
6.0 9.3 0.5 1.8 1.5 1.9 1.1 1.9 0.8 1.9 0.7 1.6 0.6 1.5 0.9 1.7
2.7 7.4 0.2 1.6 0.7 1.4 0.5 1.6 0.1 1.8 0.5 1.4 0.5 1.2 0.4 1.4
Improvement in Oral Health–related Quality of Life after Endodontic Treatment: A Prospective Longitudinal Study Pei Liu, BDS, MDS (Endo), PhD,* Colman McGrath, BA, BDentSci, DDPHRCS, MSc, FDSRCS, FFDRCSI, FFPH, MEd, PhD,*† and Gary Shun Pan Cheung, BDS, MSc, MDS, PhD, FCDSHK (Endo), FHKAM, FAMS, FRACDS, MRACDS (Endo)‡ Abstract Introduction: To date, evidence of the effectiveness of endodontic treatment and criteria of success have mainly been considered in terms of clinical outcome, and there is a lack of information of treatment outcomes from patients’ perspectives. This study aimed to assess changes in quality of life after endodontic treatment and to determine if changes in quality of life were associated with changes in patient-perceived oral health and clinical assessments of success. Methods: This longitudinal study involved 279 subjects. Patient-reported outcome measures based on oral health–related quality of life was assessed using the short form of the Oral Health Impact Profile (OHIP-14). The patients completed the assessments before endodontic treatment and 1 month and 6 months after root canal obturation. A global oral health transition assessment was ascertained by a single (global) item rating of oral health improvement and clinical assessment mainly based on the Periapical Index (PAI) of periapical radiographs. Results: There were significant changes in OHIP-14 scores over the study period after conventional orthograde endodontic treatment (from pretreatment–6 months postobturation) (P < .001). The magnitude of statistical change (effect size) was moderate (0.61) in the short-term (after 1 month) and large (0.71) in the longer-term (after 6 months). Changes in the OHIP-14 was associated with changes in patient self-rating oral health status (P < .001), which was also associated with changes in PAI scores (P < .05). Conclusions: Endodontic treatment improves quality of life. The OHIP-14 measure is both sensitive and responsive to endodontic treatment and is likely to be useful in understanding patients’ perspectives of outcomes from endodontic care. (J Endod 2014;-:1–6)
Key Words Longitudinal study, Oral Health Impact Profile, oral health, root canal therapy
E
ndodontic problems (with clinical evidence of pulp and/or periapical tissue problems) are common and key reasons why patients seek dental care (1, 2). Underpinning the demand for endodontic treatment is the growing recognition that endodontic problems have an impact on quality of life (3–5). Moreover, it is recognized that tooth loss is associated with impairment of quality of life and that the location and distribution of tooth loss affect the severity of impairment (6). Thus, retaining teeth whenever possible is important, and when the pulp and periapical tissues are affected, this typically requires endodontic treatment (7). To date, evidence of the effectiveness of endodontic treatment and criteria of success have largely been considered in terms of clinical outcome. Survival of teeth (at least in the short-term) is very high, and success rates based on strict radiographic criteria range from 30% to over 90% (8, 9). However, clinical parameters alone provide a limited understanding of oral health outcomes. There has been a paradigm shift in health care (including oral health care) to patient-reported outcomes of treatment and services (10, 11). Within the endodontic context, there has been limited study of patientreported outcomes aside from pain (12). This in part relates to the fact that although standardized (valid and reliable) measures of oral health–related quality of life (OHQoL) exist, there is scant evidence of the appropriateness of these measures to discriminate between patients with and without endodontic problems (5). Moreover, if patient-reported outcomes/quality of life measures are to be used to assess the outcome of endodontic care, it is important first to determine if the measures are sensitive to treatment (ie, their scores change [improve] after treatment, a concept referred to as ‘‘sensitivity’’) (13). Second, changes in scores should correspond with actual improvements in oral health (either clinical or subjective), a concept referred to as ‘‘responsiveness’’ (14). This study aimed to determine the sensitivity and responsiveness of a commonly used OHQoL measure with respect to orthograde endodontic treatment among adults presenting with pulp and/or periapical tissue problems.
From *Periodontology and Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China; †Center of Stomatology, The Second People’s Hospital of Shenzhen, The First Affiliated Hospital of Shenzhen University, Shenzhen, China; and ‡Comprehensive Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China. Address requests for reprints to Prof Colman McGrath, Periodontology and Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China. E-mail address: [email protected] 0099-2399/$ - see front matter Copyright ª 2014 American Association of Endodontists. http://dx.doi.org/10.1016/j.joen.2014.02.008
JOE — Volume -, Number -, - 2014
Improvement in OHQoL after Endodontic Treatment
1
Clinical Research Materials and Methods Sample This prospective longitudinal study recruited subjects referred to the discipline of comprehensive dental care at a university teaching hospital in Southern China. The inclusion criteria of this study were as follows: 1. Patients with clinical evidence of pulp and/or periapical tissue problems deemed to require root canal therapy 2. Adults 18 years and older 3. Patients of Chinese ethnicity 4. Patients who could read traditional Chinese The exclusion criteria applied were as follows: 1. Patients with serious medical conditions for which they were hospitalized in the past year and/or taking medication for their condition that required consultation with a physician before dental treatment 2. Patients with physical disabilities 3. Patients with communication difficulties noted on their record In determining the sample size requirement, a reference was made to a case-control study of OHQoL among subjects requiring endodontic treatment versus a control group in periodontal maintenance (5). The case-control study identified that there was a 41% difference in the short form of the Oral Health Impact Profile (OHIP-14) scores between the case and control subjects. On the basis that after endodontic treatment subjects’ quality of life would be at least as good as the controls (and most likely better because the control sample was composed of periodontal maintenance patients), it was anticipated that there would be a 50% improvement in OHIP-14 scores. In setting a 5% significance level and 80% power for a pretreatment group with an OHIP-14 score of 13.9 (standard deviation = 9.9) and a 6-month post-treatment score of 6.9 (50% reduction), a sample size of 189 was estimated. Considering a potential dropout rate of 25% over the 6-month period, recruitment of 250 subjects into the study was planned. This patient-centered study was approved by the local institutional review board (HKU/HA HKW IRB UW 07-1177).
Data Collection Patient-reported Outcome Measures. Patients’ OHQoL was assessed by using 1 of the most sophisticated and widely used measures—the OHIP-14 (15). The OHIP-14 consists of 14 questions arranged over 7 domains (physical functioning, physical pain, physiological disability, physical disability, psychological disability, social disability, and handicap) based on the World Health Organization’s theoretic model of disease-impairmentdisability-handicap adapted for oral health by Locker (16). A cultural and linguistically valid and reliable version of the OHIP-14 was used (17). Patients self-completed assessments per treatment, at the 1-month review, and at the 6-month review. A global oral health transition assessment was ascertained by a single (global) item rating of oral health improvement on a 5-point Likert scale with responses ranging from ‘‘much better,’’ ‘‘somewhat better,’’ ‘‘no different,’’ ‘‘somewhat worse,’’ to ‘‘much worse’’ at the 6month review appointment (14). Information on sociodemographics was also collected, including age (in years), sex, formal educational attainment level (highest level attained: no formal/primary school, secondary school, or college/ university education), and personal monthly income level (Hong Kong dollars) (HK $0–$9999/month, HK $10,000–$19,999, HK $20,000–$29,999, or HK $30,000 or above [$1 US = $7.8 HK]). 2
Liu et al.
Clinical Assessments. Periapical radiographs obtained pretreatment and at the 6-month review appointment were rated according to the PAI system by a trained and calibrated examiner blind to the subjective patient reports (18). A radiograph with a PAI score of $3 can be classified as having periapical radiolucency. To assess intrarater agreement during the study, 10% of the radiographs were re-scored blind of the initial assessment. The kappa value for agreement of PAI score >3 was 0.87. Data Analyses The profile of those who completed the study compared with those who were initially recruited into the study (baseline subjects) was undertaken to determine any nonresponse bias using the chi-square statistical test for categoric data and the Mann-Whitney U test for continuous variables. Nonparametric analysis methods were adopted in exploring changes in quality of life as a result of endodontic treatment because the quality of life data were determined using Poisson distributions. Friedman 2-way analysis of variance (ANOVA) was used to compare the relative changes in quality of life scores at baseline, at the 1-month postobturation review visit, and at the 6-month postobturation review visit. To identify if there were significant changes in quality of life between the different assessments points (ie, baseline–1 month, baseline–6 months, and 1–6 months), the Wilcoxon signed rank test, a nonparametric test equivalent to the paired t test, was used. The magnitude of the statistical difference was determined between each time period by a nonparametric method of effect size (ES) (19) calculation. In this case (unlike a case-control or cross-section study), ES equals the mean difference between 2 independent groups/standard deviation of the baseline data. The global oral health transitional ratings of oral health was categorized into 3 groups to aid in statistical analysis because of the small numbers in the ‘‘worse’’ categories: Much better = 2 Somewhat better = 1 No different/worse = 0 PAI changes between baseline and the 6-month postobturation review visit were categorized as follows: No change = 0 PAI score change of 1 = 1 PAI score change of 2 = 2 Subsequently, the associations between changes in oral health (clinical: PAI score change and patient perceived: global ratings of improvement in oral health) and changes in OHIP-14 scores at the 6-month review were explored using Kruskal-Wallis 1-way ANOVA (nonparametric version of 1-way ANOVA). In addition, the gradient of changes in quality of life scores was examined relative to the gradient of improvement in oral health to provide information on the responsiveness of the quality of life measures.
Results Response Rate and Profile of the Group A consecutive sample of 279 patients with endodontic disease met with the inclusion and exclusion criteria, and 213 (76.3%) completed OHQoL assessments at all 3 time points (Fig. 1). There was no significant difference in the sociodemographic status or clinical oral health status of those who completed the study versus those recruited as baseline (Table 1). JOE — Volume -, Number -, - 2014
Clinical Research
Figure 1. A flow diagram of patient participation in the longitudinal study.
Sensitivity There was a significant difference in the OHIP-14 summary scores over time (P < .001). Over the 6-month period, the ES was 0.71 (Table 2). Multiple-comparison statistical tests identified a significant difference in the OHIP-14 summary scores between baseline and 1 month (P < .001, ES = 0.61) and a further significant reduction in the OHIP-14 summary scores between 1 and 6 months (P < .001, ES = 0.12). Across all 7 domains of the OHIP-14, there was a significant difference in the domain scores over time (P < .001). Over the 6-month period, the ES values ranged from 0.42 (functional limitation) to 0.77 (physical pain). Multiple-comparison statistical tests identified a significant difference in all OHIP-14 domain scores between baseline and 1 month (P < .001); the ES of domains ranged from 0.24 (functional limitation) to 0.65 (psychological discomfort). A further significant reduction in 4 of the 7 OHIP-14 domain scores between 1 and 6 months was observed (P < .05). The ES ranged from 0.10 (psychological disability) to 0.18 (physical pain) among domains that significantly changed.
JOE — Volume -, Number -, - 2014
Responsiveness At the 6-month postobturation review, 42.3% (90) of patients rated their oral health as ‘‘much better,’’ 37.6% (80) as ‘‘somewhat better,’’ and 20.2% (43) as ‘‘no different/worse.’’ There was a significant association between changes in the OHIP-14 summary scores and selfratings of improvement in oral health at the 6-month follow-up (P < .001). Furthermore, there was an observed gradient of change in the OHIP-14 summary scores with respect to perceived improvement in oral health at 6 months (Table 3). Changes in all OHIP-14 domain scores were associated with self-rating of improvements in oral health at 6 months (P < .05). There was also an observed gradient of change in the OHIP-14 domain scores with respect to perceived improvement in oral health at 6 months. Compared with baseline PAI ratings (highest value per subject), at 6 months postobturation, 27.7% (59) remained the same, 31.0% (66) decreased in PAI rating by 1, and 41.3% decreased in PAI rating by 2. There was a significant association between changes in the OHIP-14
Improvement in OHQoL after Endodontic Treatment
3
Clinical Research TABLE 1. Sociodemographic, Clinical Oral Health Status, Endodontic Characteristics, and Baseline OHQoL and HQoL Scores of the Longitudinal Study Group Sociodemographics Age, mean SD Sex, % (n) Male Female Education level, % (n) Up to primary school Secondary school Postsecondary school Declined to answer Income per month, % (n) HK $0–$9,999 HK $10,000–$19,999 HK $20,000 and above Declined to answer Clinical oral health indicators Dentition status, mean SD DMFT DT FT MT Periodontal health status, % (n) CPI score 3 1>2>3 1>2=3
0.61 0.24 0.61 0.65 0.39 0.52 0.46 0.55
0.71 0.42 0.77 0.72 0.43 0.60 0.57 0.61
0.12 0.11 0.18 0.07 0.05 0.10 0.13 0.08
P values in bold show a statistically significant difference ( 0.50) and ‘‘large’’ between pretreatment and 6 months (ie, ES > 0.70) but did not improve much between 1 and 6 months (19). It is of note that among individual domains of the OHIP the magnitude of statistical change varied considerably and over time. In this study, to establish responsiveness, 2 gold standards of successful endodontic outcomes (ie, transitional ratings of oral health and changes in PAI scores) were used as recommended when interpreting responsiveness (14). Although it is acknowledged that changes in PAI at 6 months do not provide a sufficient insight into healing/nonhealing, they do provide some insight into clinical change. Most patients did perceive that their oral health had improved, but a quarter (at 1 month) and 1 in 5 patients (at 6 months) perceived it to be no better. Nevertheless, there was an observed gradient of changes in the OHIP-14 with respect to perceived changes in oral health (although not always as expected at 1 month with respect to the OHIP-14) and with respect to PAI
changes observed at 6 months. These findings confirm the responsiveness of the measures but indicate that they are more responsive to patients’ perceptions of their oral health than the traditional clinical measure of endodontic success (ie, PAI ratings). This can be expected because subjective measures (self-reports) of oral health are not necessarily correlated or associated with clinical oral health status (23). It should be noted that no attempt was made in this study to determine what factors influence OHQoL or its changes. Clearly, there are many factors that may influence this and not merely clinical factors per se. Moreover, changes in OHQoL may be associated with oral rehabilitation (after root canal obturation), and no attempt was made to consider any individual effect; rather, we report on a group of patients’ OHQoL experiences after root canal therapy (in its broadest sense). Specific details as to tooth reduction, oral rehabilitation, and so on were not recorded, and we recognize this as a limitation of this study. Moving the research (and practice) forward, it would be of value to support or refute these claims in other settings. This in itself could help provide valuable information for informed consent for patients, audit, and evidence-based practice (11). In addition, it would be useful to determine the minimum important clinical difference that is ‘‘the subjective significant difference that is meaningful to the patients’’ (24), but this is likely to require a larger sample size and a more diverse outcome such that values for OHQoL could be determined for those with ‘‘minimal or little’’ improvement (23). Further studies are warranted to investigate the main sort of changes after endodontic treatment and the key clinical
TABLE 3. Association between Observed Changes at the 6-month Follow-up in QoL (OHIP-14) and Patients’ Global Rating of Changes or PAI Score Changes (N = 213) Global rating of change of oral health (mean ± SD) Much better (n = 90) OHIP-14 score 10.2 10.5 Functional limitation 0.8 1.5 Physical pain 1.7 2.1 Psychological discomfort 2.0 2.2 Physical disability 1.3 2.0 Psychological disability 1.7 2.0 Social disability 1.3 1.8 Handicap 1.4 1.6
PAI score change (mean ± SD)
Somewhat better No different/worse
PAI no change
PAI PAI decreased 1 decreased 2
(n = 80)
(n = 43)
P value
(n = 59)
(n = 66)
(n = 88)
P value
6.0 9.3 0.5 1.8 1.5 1.9 1.1 1.9 0.8 1.9 0.7 1.6 0.6 1.5 0.9 1.7
2.7 7.4 0.2 1.6 0.7 1.4 0.5 1.6 0.1 1.8 0.5 1.4 0.5 1.2 0.4 1.4
