WORK A Journal of Prevention,
Assessment & Rehabilitation
ELSEVIER
Work 9 (1997) 3-11
Review paper
A review of functional capacity evaluation practice Libby Gibson*, Jenny Strong Department of Occupational Therapy, The University of Queensland, Brisbane, Queensland 4072, Australia
Received 3 September 1996; accepted 16 October 1996
Abstract
Objectives: This study evaluated the implementation of recommendations from a prior review of functional capacity evaluation practice in a regionalised rehabilitation service. The evaluation considered the acceptance of the recommendations and the current level of consistency of approach in practice. Study design: The study was qualitative in nature, using a descriptive survey and a focus group. Participants were occupational therapists of a major rehabilitation provider in Queensland, Australia. Eighteen of 48 therapists (38%) responded to the questionnaire. Eight therapists participated in the focus group. Results: The results indicated some acceptance of the recommendations for functional capacity evaluation in areas such as procedure, reporting, equipment and model of evaluation. Further research into the reliability and validity of functional capacity evaluation was indicated. Discussion: The low response rate did not allow conclusive results. However, the findings provided some evidence of consistency in functional capacity evaluation practice. The results are discussed in relation to current issues in functional capacity evaluation practice. © 1997 Elsevier Science Ireland Ltd. Keywords: Functional capacity evaluation; Models; Inter-rater reliability; Validity
1. Introduction
Functional capacity evaluation (FeE) is a tool used in occupational rehabilitation to evaluate a
* Corresponding author.
person's functional physical abilities for work (Lechner et aI., 1991). The evaluator observes the person performing physical, work-related tasks, including standing, lifting, carrying, reaching and kneeling. Recommendations are made about the functional impact of the person's disability or injury on work performance, including the need
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L. Gibson, J. Strong / Work 9 (1997) 3-11
for modifications of duties and/or the need for workplace aids or modifications (McGuire, 1995). There has been only limited scientific research on FCE (Lechner et aI., 1991, 1994; Isernhagen, 1992; Tramposh, 1992; Vasudevan, 1996), particularly of its reliability and validity. Despite this, FCE has been acknowledged as a potentially valuable tool in the evaluation of work capacity (Lechner et aI., 1991; Isernhagen, 1992; Tramposh, 1992; Pincus and Bampton, 1995). Rehabilitation providers, workers compensation and legal authorities as well as employment and social security departments in Australia use this tool to make major decisions about service provision and compensation. In 1994 the first author undertook a project for a major rehabilitation provider in Queensland. Australia that investigated and recommended an approach to FCE for use by occupational therapists and physiotherapists working for that provider. The investigations found that there was a large variety of practice in FCE in Australia, both within and across government and private rehabilitation sectors and private practice. There was also a high commercial interest in the development and sale of FCE tools. A review of the literature found that limited scientific research had been conducted on this widely used assessment approach and the commercial tools used, particularly the reliability and validity of approaches. The conclusion was that there was no clear indication in practice nor the literature for a demonstrated superior approach or tool (Gibson, 1994, unpublished manuscript). Five criteria established by the United States National Institute of Occupational Safety and Health (NIOSH) as guidelines for evaluation procedures and used as criteria for appraisal of FCEs (Matheson, 1990) were used in the 1994 review of FCE approaches. These were safety, reliability\ validity, practicality and utility. The following is a summary of the main issues in FCE practice with regard to these criteria. 1.1. Safety
Safety is given top priority in FCE approaches. Important safety issues include the need for a
qualified and well trained practitioner to conduct the evaluation (Dyson, 1990; Isernhagen, 1993; Abdel-Moty et aI., 1996), the use of a physical screening prior to the FCE to assess any underlying impairments which may be contraindicated for the FCE (Tramposh, 1992; Isernhagen, 1993), consideration of the medical precautions and contraindications for FCE (Hart et aI., 1993) and the technique used for manual handling components of the evaluation (Abdel-Moty et aI., 1996). Another key issue related to safety of FCEs is the model used to determine the end-points of the evaluation. There are three main models that have been adopted from the manual handling field, these being the biomechanical, the physiological (also known as the cardiovascular or metabolic) and the psychophysical. Matheson (1988) defined these in relation to work hardening but these definitions also fit well for FCE practice. Each model relates to how the individual works within the constraints of a particular body system. The biomechanical model relates to the musculoskeletal and neuromuscular systems, the cardiovascular or metabolic model relates to the cardiovascular, pulmonary and metabolic systems and the psychophysical model relates to the person's cognitive-perceptual system such as self-perception, beliefs and expectations (Matheson, 1988). There has been debate over the superiority of one model over another (Isernhagen, 1992). The psychophysical model is widely accepted in the design of manual handling tasks as being a satisfactory method of predicting lifting capacity (Mayer et aI., 1988; Chaffin and Anderson, 1991). Khalil et al. (1987) proposed a psychophysical model of acceptable maximum effort (AME) for assessing function in persons with chronic pain. This model allows the person to exert effort within a perceived acceptable level of pain (Khalil et aI., 1987). The psychophysical model has been supported as being the primary model to be used in FCEs to allow the person to nominate when their safe level of lifting has been reached (Ogden-Niemeyer, 1991). In opposition, Isernhagen (1993) has expressed concerns about allowing the person with an injury to determine their own safe limit of lifting. In response, she proposed the kinesiophysical model, which in-
L. Gibson,1. Strong / Work 9 (1997) 3-11
volves using observation of movement patterns to evaluate safe levels of function (Isernhagen, 1993). Use of the physiological model has also been advocated for safety reasons. Individuals undergoing FCE may be considerably deconditioned so monitoring of cardiovascular function, by heartrate and blood pressure monitoring, is advocated (Bhambani et aI., 1994). 1.2. Reliability
The reliability of a measure refers to its consistency (Rothstein, 1985). Inter-rater reliability is the consistency of results between trained observers and is essential for FCEs. At the time of the review in 1994, no known studies had been conducted on the inter-rater reliability of FCE procedures (Lechner et aI., 1991; Tramposh, 1992). Subsequent to the review, support for the inter-rater reliability of one criterion-referenced approach has been established (Lechner et aI., 1994). In addition, Smith (1994) demonstrated good inter-rater reliability for therapists' ability to determine safe vs. unsafe lifts and maximum lifting capacity in a kinesiophysical approach to FCE. Only the study by Lechner et aI. (1994) examined the inter-rater reliability of the whole battery and the overall determinations made in a FCE. 1.3. Validity
Validity of an evaluation is the extent to which it measures what it is intended to measure (Johnston et aI., 1992) and whether the judgements or inferences made from an evaluation can be made legitimately on the basis of the measurements obtained from the evaluation (Rothstein 1985). In 1994, at the time of the FCE review, no research had been completed on the validity of FCEs (Lechner et aI., 1991; Tramposh, 1992). Macdonald (1992) suggested that an ideal work capacity evaluation needed to firstly identify and measure the various demands of the work, then identify the levels of capacities needed to cope with these demands, and finally test the person's capacities in terms of the predetermined demands of the work. The best way to achieve this is by analysing
5
the job demands before conducting the FCE to set the performance criteria for the FCE. Predictive validity, or the extent to which a measure is able to predict a future event (Johnston et aI., 1992), is an important validity to establish for FCEs as the outcome of the FCE is a prediction of the person's physical work capacity. The predictive validity of an approach to FCE was examined by Smith et aI. (1986). Support was given to the ability of the FCE to predict return to work. However, this study had low follow-up rates and some design flaws (Lechner et aI., 1991). In addition to recently establishing the inter-rater reliability of their approach, Lechner et aI. (1994) demonstrated some convergent validity of the approach by comparing the level of work predicted by the FCE with the actual working level of the client. 1.4. Practicality
Practicality of an FCE requires that it is easy to administer and interpret, of reasonable cost in terms of equipment, space and training and acceptable to the person being evaluated (Matheson, 1990; Christiansen, 1993). 1.5. Utility
The utility or usefulness of an evaluation (Matheson et aI., 1996) refers to the suitability of the evaluation for the intended purpose, how it meets the needs of the client and referrer (Matheson et aI., 1996) and the ease of its use and its acceptance by the user and the person being evaluated. 2. Project outcome As indicated earlier, at the time of the FCE review in 1994, there was no scientific evidence for the superiority of anyone existing approach over another. The outcome of the project was that a framework for FCE practice was proposed, including recommendations for a non-commercial approach. One of the major recommendations was for use of a criterion-referenced approach
L Gibson, 1. Strong /Work 9 (1997) 3-11
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rather than the use of norms for determination of performance. For consistency in the content and criteria of the approach, use of the physical job demands and physical categories of work defined in the Dictionary of Occupational Titles (DOT) (1986) and Handbook of Analysing Jobs (1991) was recommended. Other FeE approaches have since been reported which are based on the physical demands in the DOT (Fishbain et at, 1994; Lechner et at, 1994). Lechneret at (1991) found that most commercially available FCE tools provide limited coverage of the job demands listed in the DOT or require a range of expensive equipment items to obtain adequate coverage. It was recommended that where the client has a job to which he or she can return, the specific job requirements provide the criteria and content for measurement. Use of job analysis prior to the FCE was advocated as a means of improving the validity of the evaluation. Where the client has no job to return to and therefore to be evaluated against, the use of the physical work categories from the DOT was advocated. Other recommendations from the review included: •
the use of heart-rate and blood pressure monitoring, primarily for safety purposes; • the use of a combination of models for evaluation, i.e. biomechanical, physiological and psychophysical; • the use of the following adjuncts to the FeE: • collection of background information; • client report of tolerances; • physical screening; • precautions and contraindications for FeE, including the need for medical stability to conduct the FeE and precautions regarding evaluation of clients with known cardiovascular, cardiopulmonary or hypertensive disease; • the use of a standard report format; and • the use of a range of equipment to cover evaluation of the physical demands from the DOT, including adjustable shelving, weights, weight container, ladder, trolley and hand function tests. In 1996 a descriptive study was undertaken to
evaluate the implementation of the recommendations from the 1994 review, in terms of acceptance of the recommendations and the current level of consistency of the approach in practice. This paper reports the results of this study and, in the process, describes many current issues relevant to FeE practice in general. 3. Materials and methods The study was qualitative in nature, using a descriptive survey and a focus group. The questionnaire aimed to evaluate specific elements of FCE practice while the focus group concentrated on more qualitative and conceptual areas of practice. All participants were occupational therapists, employed by the rehabilitation provider. The research was given ethical clearance and management approval before commencement. A questionnaire was distributed by electronic mail to 48 occupational therapists across Queensland, six of whom are male. A total of 18 (38%) completed questionnaires were received. The low response rate may be explained by two factors, the first being that it is known to the researchers that a number of the occupational therapists in the organisation do not personally conduct FeEs, so have a smaller interest in them, and secondly that the questionnaires were distributed at a time of major change in the organisation. The recipients of the questionnaire were also asked to supply a copy of a sample report of an FeE they had conducted and a copy of their Unit's protocol for conducting FeEs, if available. Thirteen reports and seven protocols were received for review. The results of the questionnaire were analysed by examination of the frequency of responses. The focus group consisted of eight occupational therapists, seven females and one male. The focus group utilised structured questions and also allowed free discussion. The group was moderated and transcribed by individuals independent of the rehabilitation provider, to ensure anonymity of responses. The focus group results were analysed initially by each question and then by theme (Krueger, 1988). Only the thematic analysis will be reported here.
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4. Results 4.1. Questionnaire
All but two of the therapists (88%) who conducted FCBs in their Units reported that they used a standard protocol. Similarly, 88% of the respondents conducting FCEs indicated that they used the physical categories of work from the DOT to make recommendations about the person's capacity for work. This was supported by review of the sample reports with 12 of the reports (92%) including reference to the physical categories of work from the DOT. Table 1 shows the topics that were commonly covered in the sample reports. The length of the reports ranged from 2 to 11 pages, with an average length of 4.5 A4 typed pages. The therapists were asked to list the indicators they commonly used to determine the person's level of pedormance in the FCB. All therapists reported using a combination of observed and reported data to determine pedormance. Nine of the therapists nominated a range of indicators which could be classed under two of the known models, primarily from the biomechanical and psychophysical models. The remaining eight therapists nominated a range of indicators from all
Table 1 Topics covered by the sample reports • reason for referral or purpose of the evaluation (62%) • background information about the disability or injury (62%) • client's perception of their capacities (85%) • current activity or exercise level (77%) • work history and/or job demands (92%) • consistency of performance (70%) • pain behaviour (61 %) • safety of technique /body mechanics used (70%) • functional abilities (92%) • functional restrictions (92%) • physical categories of work from the DOT (92%) • recommendations about the person's job or vocational goal (100%) • recommendations for the person's rehabilitation program (92%)
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three models, that is, the biomechanical, psychophysical and physiological. Eight respondents (47%) stated that they used heart-rate monitoring during the FCE but some of these also commented that this was not routinely used and used only for some cases, such as at risk clients. Only two therapists replied that they used blood-pressure monitoring. Therapists were asked to list equipment used in their Unit to conduct FCEs. All listed a range of equipment to cover evaluation of many of the physical demands from the DOT, including adjustable shelving, weight containers and weights, standardised upper limb function tests, ladders and trolleys. Seven (41%) stated that they used the Spinal Function Sort, a measure of perceived capacity for physical work-related tasks.
4.2. Focus group One of the major themes to emerge from the focus group was the conviction that FCE practice is much more consistent in the organisation than before the 1994 FCB project. However, there were concerns expressed about the consistency of interpretation of the results of the FCE and the rating of the person's pedormance in the FCE. The desire for greater consistency and structure in the interpretation process was tempered by the strong desire for flexibility of practice. Another issue of interest, which is related to the concern about consistency of interpretation, was the concern about the validity of the results from the FCB. There was concern too about the relevance of the testing situation to the actual workplace ~nd about assessing the cumulative effect of physIcal pedormance and generalisation of these results to actual capacity in the workplace. The participants gave strong support to the psychophysical model, that is the person's perception of their capacities, in evaluating pedormance. Although a combination of models was used, as recommended from the FCE review, the psychophysical is given the most credence in the final analysis, as there was a belief that this was most reflective of actual pedormance. Comments were that the biomechanical was originally the
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L. Gibson, J. Strong / Work 9 (1997) 3-11
model of preference but that there has been a shift to the psychophysical model. The therapists also firmly stated the need to use the purpose of the FeE and the nature of the person's disability to guide the criteria used in the FeE. In terms of improvements of the current approach, there was an identified need for attention to other elements of the person's function with regard to work capacities. These included cognitive, sensory and psychophysical areas of function. One participant commented that the incorporation of items for testing of maximum voluntary effort, particularly for external agency assessments, such as for insurance companies, would be a useful addition in some cases, 'just so that we can know what other issues are going on with the clients and why they may not be performing.' 4. Discussion The primary aim of this research was to evaluate the use of FeE by occupational therapists within the rehabilitation provider in terms of acceptance of the recommendations of the review conducted in 1994. The response rate for the questionnaire was low, so the outcomes of the survey cannot be conclusive. However, based on the responses received, supplemented by the results of the focus group, it appears that the recommendations of the 1994 review have been adopted, albeit at varying levels, and that there is greater consistency of FeE practice in the organisation currently rather than prior to the 1994 project. The following recommendations of the 1994 FeE project appear to have been implemented by the majority of respondents: use of a criterion-referenced approach based on the physical demands and physical work categories from the DOT, use of a combination of the psychophysical, biomechanical and physiological models to determine performance in the FeE, tailoring of the FeE to the client's job or vocational goal and use of a standard report format. Although the report samples were provided voluntarily and therefore self-selected by the therapists, there was evidence of some consistency in the headings used and the topics covered. The variation in the lengths, however, was indica-
tive of the variety in report-writing practice overall. In terms of the minimum requirements for FeE reports suggested by Vasudevan (1996), the sample reports provided appear sound. These requirements include reporting of observations about the person's motivation, consistency of performance, pain behaviours, safety of function, and specific abilities and deficits (Vasudevan, 1996). In terms of the model of evaluation, it appears that therapists are using a combination of the models, as recommended. The focus group discussion revealed that the psychophysical model, that is, the person's perceptions of their capacities, is given the ultimate credence in practice. This may be substantiated, in the case of clients with chronic back pain at least, by the strong evidence for psychosocial rather than physical factors predicting eventual outcome, including return to work (Gallagher et aI., 1989; Milhous et aI., 1989; Eklund, 1992; Frymoyer, 1992; Lancourt and Kettelhut, 1992). However, support for the use of the combination of models is evidenced by a recent comparison of perceived vs. observed capacity in a FeE by subjects with low back pain (Piela et aI., 1996). The results found a tendency for overestimation of lifting capacities and underestimation of standing tolerance, supporting use of observation of function rather than self-report alone (Piela et aI., 1996). The Borg Rating of Perceived Exertion (RPE) scale (Borg, 1982) has been used in evaluations to quantify the person's perceptions of their exertion (Jacobs et aI., 1988; Bhambani et aI., 1994; Matheson et aI., 1995) and may provide a quantifiable way of measuring psychophysical aspects of performance during the FeE. The practice of regular rating of subjective pain intensity throughout the FeE may be of questionable benefit, at least for assessing the person with chronic pain (Rudy et aI., 1996). This practice may negatively influence such a person's performance and may not provide a true indication of actual function (Rudy et aI., 1996). With regards to use of the physiological model, the use of heart-rate and blood-pressure monitoring by the therapists appears limited. This is not surprising as it is a relatively new development in FeE and specific guidelines for its use are not widely available. Training in the use of
L. Gibson,l Strong / Work 9 (1997) 3-11
the equipment and clearer guidelines for endpoints appears to be indicated. The primary reason for heart-rate and blood-pressure monitoring is precautionary, as individuals with disabilities or injuries can have poor levels of cardiorespiratory fitness and therefore require at least heart-rate monitoring during FCEs (Bhambani et aI., 1994). The use of heart-rate monitoring only if there is a history of cardiac problems is contrary to the recommendations of the FCE report, which recommended that evaluation of such clients is contraindicated in settings where there is no access to resuscitation equipment or personnel (Gibson 1994, unpublished manuscript). This is consistent with recommendations by Matheson et aI. (1995), who exclude testing of individuals on the EPIC Lift Capacity test who have known risk factors, without appropriate medical supervision and emergency response capabilities (Matheson et aI., 1995). Matheson et al. (1995) also use an upper limit of 85% of maximum heart rate for age (that is, 85% of 220 - age), as do other published accounts of lifting protocols (Mayer et aI., 1988; Hazard et aI., 1993) as a point for ceasing the evaluation. In an overview of the EPIC Lift Capacity (ELC) test, Matheson (1995) also described additional protocols for measuring physiological indicators of performance. These include guidelines for evaluation of individuals using heart rate-limiting medications. More research is required to establish clearer guidelines for heartrate and blood-pressure monitoring in terms of end-points for FCE. Although the therapists who participated in the study expressed concerns about consistency across raters and in determinations made from the FCEs, there appears to be greater consistency of FCE practice in the rehabilitation provider than prior to the project. Inter-rater reliability and predictive validity need to be established through formal research. There is a need to standardise the parameters of the determinations made from an FCE and examine the reliability of these determinations between assessors (Lechner et aI., 1991). Predictive validity of FCEs, probably the most important validity (Macdonald, 1992), remains to be established. Such validity needs to be determined by initially specifying the level of work a
9
person can perform (e.g. sedentary, light, medium or heavy), then seeing if they successfully do this on return to work (Lechner et aI., 1991). Actual performance on the job would be the 'gold standard' for validity testing. In terms of practicality and utility, the recommended approach appears to have some support. A criticism of the approach was the lack of normed data for the evaluation. Norm-referenced testing compares an individual's performance against that of a representative sample of people (Rothstein, 1985). To be confident of such a comparison, the sample must be specific to the population being tested, not only in terms of geographicallocation (Macdonald, 1992) but also variables such as disability type (Mathiowetz, 1993) and fitness level (Macdonald, 1992). The value of norm-referenced testing for FCE is questionable. Even if population-specific norms were available, their value in relating the person's performance to actual job demands is limited. Another perceived need amongst the therapists was for more formal testing of effort in the FCE. Procedures for testing whether the person provides full effort, called sincerity of effort or maximum voluntary effort testing, have been described in detail (Matheson, 1990). Use of the coefficient of variation (standard deviation divided by the mean) on tests designed to test voluntary maximal effort has been advocated (Matheson, 1990). Recent research of coefficient of variations on different isometric tests which found differences between tests has cautioned against the sole use of the coefficient of variation (Simonsen, 1995) for assessment of sincerity of effort. Examination of a commonly advocated technique using the curve shape of grip strength measurements on a dynamometer (Stokes, 1983) found that genuine weakness of grip can effect the curve shape (Hamilton Fairfax et aI., 1994). The authors cautioned about the use of this method as an indicator of sincerity of effort. A review of trunk strength testing using iso-machines by Newton and Waddell (1993) did not support their use for assessment of effort. In an examination of psychological factors and maximal effort of subjects with low back pain during a FCE, Kaplan et aI. (1996) found submax-
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L. Gibson, J. Strong / Work 9 (1997) 3-11
imal effort, as measured by the three methods of maximal effort testing, was associated with higher reported depression, perceived disability and anxiety and lower scores on perceived self-efficacy for performing the FCE and for return to work. These authors recommended thorough assessment of such psychological factors prior to a FCE. Particularly for the person with chronic pain, the use of a more cognitive-behaviourally oriented model for FCE has been advocated (Rudy et al., 1996). Use of reliable and valid measures of subjective data such as perceived capacity and self-efficacy, which may explain the discrepancy between actual and perceived function, has been reCommended (Papciak and Feuerstein, 1991; Gibson and Strong, 1996; Kaplan et al., 1996; Rudy et al., 1996). Similarly, Lechner et al. (1991) called for formal quantification of the person's perception of the tasks in FCE, such as the perceived effort to perform the task, the perceived difficulty of the task and the perceived importance of the task to the person's work situation. There are many issues surrounding FCE and its use in disability evaluation and occupational rehabilitation (Abdel-Moty, 1996; Vasudevan, 1996) which need to be considered, including the influence of behavioural and environmental factors (Velozo, 1993; Rudy et al., 1996). Greater consideration of workplace factors and their influence on return to work is required (Feuerstein and Thebarge, 1991; Velozo, 1993; Rudy et al., 1996). Further research and debate is needed to clarify the many issues and improve practice. In addition to the much called for research into the reliability and validity of FCE procedures, examination of the comparative predictive power of perceived capacity and observed capacity for work would be valuable. Acknowledgements
The authors gratefully acknowledge the therapists who participated in the study and the management of the Commonwealth Rehabilitation Service, Queensland for their support of this research.
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Assessment & Rehabilitation
ELSEVIER
Work 9 (1997) 3-11
Review paper
A review of functional capacity evaluation practice Libby Gibson*, Jenny Strong Department of Occupational Therapy, The University of Queensland, Brisbane, Queensland 4072, Australia
Received 3 September 1996; accepted 16 October 1996
Abstract
Objectives: This study evaluated the implementation of recommendations from a prior review of functional capacity evaluation practice in a regionalised rehabilitation service. The evaluation considered the acceptance of the recommendations and the current level of consistency of approach in practice. Study design: The study was qualitative in nature, using a descriptive survey and a focus group. Participants were occupational therapists of a major rehabilitation provider in Queensland, Australia. Eighteen of 48 therapists (38%) responded to the questionnaire. Eight therapists participated in the focus group. Results: The results indicated some acceptance of the recommendations for functional capacity evaluation in areas such as procedure, reporting, equipment and model of evaluation. Further research into the reliability and validity of functional capacity evaluation was indicated. Discussion: The low response rate did not allow conclusive results. However, the findings provided some evidence of consistency in functional capacity evaluation practice. The results are discussed in relation to current issues in functional capacity evaluation practice. © 1997 Elsevier Science Ireland Ltd. Keywords: Functional capacity evaluation; Models; Inter-rater reliability; Validity
1. Introduction
Functional capacity evaluation (FeE) is a tool used in occupational rehabilitation to evaluate a
* Corresponding author.
person's functional physical abilities for work (Lechner et aI., 1991). The evaluator observes the person performing physical, work-related tasks, including standing, lifting, carrying, reaching and kneeling. Recommendations are made about the functional impact of the person's disability or injury on work performance, including the need
1051-9815/97/$17.00 © 1997 Elsevier Science Ireland Ltd. All rights reserved. PI! S1051-9815(97) 00257-9
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for modifications of duties and/or the need for workplace aids or modifications (McGuire, 1995). There has been only limited scientific research on FCE (Lechner et aI., 1991, 1994; Isernhagen, 1992; Tramposh, 1992; Vasudevan, 1996), particularly of its reliability and validity. Despite this, FCE has been acknowledged as a potentially valuable tool in the evaluation of work capacity (Lechner et aI., 1991; Isernhagen, 1992; Tramposh, 1992; Pincus and Bampton, 1995). Rehabilitation providers, workers compensation and legal authorities as well as employment and social security departments in Australia use this tool to make major decisions about service provision and compensation. In 1994 the first author undertook a project for a major rehabilitation provider in Queensland. Australia that investigated and recommended an approach to FCE for use by occupational therapists and physiotherapists working for that provider. The investigations found that there was a large variety of practice in FCE in Australia, both within and across government and private rehabilitation sectors and private practice. There was also a high commercial interest in the development and sale of FCE tools. A review of the literature found that limited scientific research had been conducted on this widely used assessment approach and the commercial tools used, particularly the reliability and validity of approaches. The conclusion was that there was no clear indication in practice nor the literature for a demonstrated superior approach or tool (Gibson, 1994, unpublished manuscript). Five criteria established by the United States National Institute of Occupational Safety and Health (NIOSH) as guidelines for evaluation procedures and used as criteria for appraisal of FCEs (Matheson, 1990) were used in the 1994 review of FCE approaches. These were safety, reliability\ validity, practicality and utility. The following is a summary of the main issues in FCE practice with regard to these criteria. 1.1. Safety
Safety is given top priority in FCE approaches. Important safety issues include the need for a
qualified and well trained practitioner to conduct the evaluation (Dyson, 1990; Isernhagen, 1993; Abdel-Moty et aI., 1996), the use of a physical screening prior to the FCE to assess any underlying impairments which may be contraindicated for the FCE (Tramposh, 1992; Isernhagen, 1993), consideration of the medical precautions and contraindications for FCE (Hart et aI., 1993) and the technique used for manual handling components of the evaluation (Abdel-Moty et aI., 1996). Another key issue related to safety of FCEs is the model used to determine the end-points of the evaluation. There are three main models that have been adopted from the manual handling field, these being the biomechanical, the physiological (also known as the cardiovascular or metabolic) and the psychophysical. Matheson (1988) defined these in relation to work hardening but these definitions also fit well for FCE practice. Each model relates to how the individual works within the constraints of a particular body system. The biomechanical model relates to the musculoskeletal and neuromuscular systems, the cardiovascular or metabolic model relates to the cardiovascular, pulmonary and metabolic systems and the psychophysical model relates to the person's cognitive-perceptual system such as self-perception, beliefs and expectations (Matheson, 1988). There has been debate over the superiority of one model over another (Isernhagen, 1992). The psychophysical model is widely accepted in the design of manual handling tasks as being a satisfactory method of predicting lifting capacity (Mayer et aI., 1988; Chaffin and Anderson, 1991). Khalil et al. (1987) proposed a psychophysical model of acceptable maximum effort (AME) for assessing function in persons with chronic pain. This model allows the person to exert effort within a perceived acceptable level of pain (Khalil et aI., 1987). The psychophysical model has been supported as being the primary model to be used in FCEs to allow the person to nominate when their safe level of lifting has been reached (Ogden-Niemeyer, 1991). In opposition, Isernhagen (1993) has expressed concerns about allowing the person with an injury to determine their own safe limit of lifting. In response, she proposed the kinesiophysical model, which in-
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volves using observation of movement patterns to evaluate safe levels of function (Isernhagen, 1993). Use of the physiological model has also been advocated for safety reasons. Individuals undergoing FCE may be considerably deconditioned so monitoring of cardiovascular function, by heartrate and blood pressure monitoring, is advocated (Bhambani et aI., 1994). 1.2. Reliability
The reliability of a measure refers to its consistency (Rothstein, 1985). Inter-rater reliability is the consistency of results between trained observers and is essential for FCEs. At the time of the review in 1994, no known studies had been conducted on the inter-rater reliability of FCE procedures (Lechner et aI., 1991; Tramposh, 1992). Subsequent to the review, support for the inter-rater reliability of one criterion-referenced approach has been established (Lechner et aI., 1994). In addition, Smith (1994) demonstrated good inter-rater reliability for therapists' ability to determine safe vs. unsafe lifts and maximum lifting capacity in a kinesiophysical approach to FCE. Only the study by Lechner et aI. (1994) examined the inter-rater reliability of the whole battery and the overall determinations made in a FCE. 1.3. Validity
Validity of an evaluation is the extent to which it measures what it is intended to measure (Johnston et aI., 1992) and whether the judgements or inferences made from an evaluation can be made legitimately on the basis of the measurements obtained from the evaluation (Rothstein 1985). In 1994, at the time of the FCE review, no research had been completed on the validity of FCEs (Lechner et aI., 1991; Tramposh, 1992). Macdonald (1992) suggested that an ideal work capacity evaluation needed to firstly identify and measure the various demands of the work, then identify the levels of capacities needed to cope with these demands, and finally test the person's capacities in terms of the predetermined demands of the work. The best way to achieve this is by analysing
5
the job demands before conducting the FCE to set the performance criteria for the FCE. Predictive validity, or the extent to which a measure is able to predict a future event (Johnston et aI., 1992), is an important validity to establish for FCEs as the outcome of the FCE is a prediction of the person's physical work capacity. The predictive validity of an approach to FCE was examined by Smith et aI. (1986). Support was given to the ability of the FCE to predict return to work. However, this study had low follow-up rates and some design flaws (Lechner et aI., 1991). In addition to recently establishing the inter-rater reliability of their approach, Lechner et aI. (1994) demonstrated some convergent validity of the approach by comparing the level of work predicted by the FCE with the actual working level of the client. 1.4. Practicality
Practicality of an FCE requires that it is easy to administer and interpret, of reasonable cost in terms of equipment, space and training and acceptable to the person being evaluated (Matheson, 1990; Christiansen, 1993). 1.5. Utility
The utility or usefulness of an evaluation (Matheson et aI., 1996) refers to the suitability of the evaluation for the intended purpose, how it meets the needs of the client and referrer (Matheson et aI., 1996) and the ease of its use and its acceptance by the user and the person being evaluated. 2. Project outcome As indicated earlier, at the time of the FCE review in 1994, there was no scientific evidence for the superiority of anyone existing approach over another. The outcome of the project was that a framework for FCE practice was proposed, including recommendations for a non-commercial approach. One of the major recommendations was for use of a criterion-referenced approach
L Gibson, 1. Strong /Work 9 (1997) 3-11
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rather than the use of norms for determination of performance. For consistency in the content and criteria of the approach, use of the physical job demands and physical categories of work defined in the Dictionary of Occupational Titles (DOT) (1986) and Handbook of Analysing Jobs (1991) was recommended. Other FeE approaches have since been reported which are based on the physical demands in the DOT (Fishbain et at, 1994; Lechner et at, 1994). Lechneret at (1991) found that most commercially available FCE tools provide limited coverage of the job demands listed in the DOT or require a range of expensive equipment items to obtain adequate coverage. It was recommended that where the client has a job to which he or she can return, the specific job requirements provide the criteria and content for measurement. Use of job analysis prior to the FCE was advocated as a means of improving the validity of the evaluation. Where the client has no job to return to and therefore to be evaluated against, the use of the physical work categories from the DOT was advocated. Other recommendations from the review included: •
the use of heart-rate and blood pressure monitoring, primarily for safety purposes; • the use of a combination of models for evaluation, i.e. biomechanical, physiological and psychophysical; • the use of the following adjuncts to the FeE: • collection of background information; • client report of tolerances; • physical screening; • precautions and contraindications for FeE, including the need for medical stability to conduct the FeE and precautions regarding evaluation of clients with known cardiovascular, cardiopulmonary or hypertensive disease; • the use of a standard report format; and • the use of a range of equipment to cover evaluation of the physical demands from the DOT, including adjustable shelving, weights, weight container, ladder, trolley and hand function tests. In 1996 a descriptive study was undertaken to
evaluate the implementation of the recommendations from the 1994 review, in terms of acceptance of the recommendations and the current level of consistency of the approach in practice. This paper reports the results of this study and, in the process, describes many current issues relevant to FeE practice in general. 3. Materials and methods The study was qualitative in nature, using a descriptive survey and a focus group. The questionnaire aimed to evaluate specific elements of FCE practice while the focus group concentrated on more qualitative and conceptual areas of practice. All participants were occupational therapists, employed by the rehabilitation provider. The research was given ethical clearance and management approval before commencement. A questionnaire was distributed by electronic mail to 48 occupational therapists across Queensland, six of whom are male. A total of 18 (38%) completed questionnaires were received. The low response rate may be explained by two factors, the first being that it is known to the researchers that a number of the occupational therapists in the organisation do not personally conduct FeEs, so have a smaller interest in them, and secondly that the questionnaires were distributed at a time of major change in the organisation. The recipients of the questionnaire were also asked to supply a copy of a sample report of an FeE they had conducted and a copy of their Unit's protocol for conducting FeEs, if available. Thirteen reports and seven protocols were received for review. The results of the questionnaire were analysed by examination of the frequency of responses. The focus group consisted of eight occupational therapists, seven females and one male. The focus group utilised structured questions and also allowed free discussion. The group was moderated and transcribed by individuals independent of the rehabilitation provider, to ensure anonymity of responses. The focus group results were analysed initially by each question and then by theme (Krueger, 1988). Only the thematic analysis will be reported here.
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4. Results 4.1. Questionnaire
All but two of the therapists (88%) who conducted FCBs in their Units reported that they used a standard protocol. Similarly, 88% of the respondents conducting FCEs indicated that they used the physical categories of work from the DOT to make recommendations about the person's capacity for work. This was supported by review of the sample reports with 12 of the reports (92%) including reference to the physical categories of work from the DOT. Table 1 shows the topics that were commonly covered in the sample reports. The length of the reports ranged from 2 to 11 pages, with an average length of 4.5 A4 typed pages. The therapists were asked to list the indicators they commonly used to determine the person's level of pedormance in the FCB. All therapists reported using a combination of observed and reported data to determine pedormance. Nine of the therapists nominated a range of indicators which could be classed under two of the known models, primarily from the biomechanical and psychophysical models. The remaining eight therapists nominated a range of indicators from all
Table 1 Topics covered by the sample reports • reason for referral or purpose of the evaluation (62%) • background information about the disability or injury (62%) • client's perception of their capacities (85%) • current activity or exercise level (77%) • work history and/or job demands (92%) • consistency of performance (70%) • pain behaviour (61 %) • safety of technique /body mechanics used (70%) • functional abilities (92%) • functional restrictions (92%) • physical categories of work from the DOT (92%) • recommendations about the person's job or vocational goal (100%) • recommendations for the person's rehabilitation program (92%)
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three models, that is, the biomechanical, psychophysical and physiological. Eight respondents (47%) stated that they used heart-rate monitoring during the FCE but some of these also commented that this was not routinely used and used only for some cases, such as at risk clients. Only two therapists replied that they used blood-pressure monitoring. Therapists were asked to list equipment used in their Unit to conduct FCEs. All listed a range of equipment to cover evaluation of many of the physical demands from the DOT, including adjustable shelving, weight containers and weights, standardised upper limb function tests, ladders and trolleys. Seven (41%) stated that they used the Spinal Function Sort, a measure of perceived capacity for physical work-related tasks.
4.2. Focus group One of the major themes to emerge from the focus group was the conviction that FCE practice is much more consistent in the organisation than before the 1994 FCB project. However, there were concerns expressed about the consistency of interpretation of the results of the FCE and the rating of the person's pedormance in the FCE. The desire for greater consistency and structure in the interpretation process was tempered by the strong desire for flexibility of practice. Another issue of interest, which is related to the concern about consistency of interpretation, was the concern about the validity of the results from the FCB. There was concern too about the relevance of the testing situation to the actual workplace ~nd about assessing the cumulative effect of physIcal pedormance and generalisation of these results to actual capacity in the workplace. The participants gave strong support to the psychophysical model, that is the person's perception of their capacities, in evaluating pedormance. Although a combination of models was used, as recommended from the FCE review, the psychophysical is given the most credence in the final analysis, as there was a belief that this was most reflective of actual pedormance. Comments were that the biomechanical was originally the
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model of preference but that there has been a shift to the psychophysical model. The therapists also firmly stated the need to use the purpose of the FeE and the nature of the person's disability to guide the criteria used in the FeE. In terms of improvements of the current approach, there was an identified need for attention to other elements of the person's function with regard to work capacities. These included cognitive, sensory and psychophysical areas of function. One participant commented that the incorporation of items for testing of maximum voluntary effort, particularly for external agency assessments, such as for insurance companies, would be a useful addition in some cases, 'just so that we can know what other issues are going on with the clients and why they may not be performing.' 4. Discussion The primary aim of this research was to evaluate the use of FeE by occupational therapists within the rehabilitation provider in terms of acceptance of the recommendations of the review conducted in 1994. The response rate for the questionnaire was low, so the outcomes of the survey cannot be conclusive. However, based on the responses received, supplemented by the results of the focus group, it appears that the recommendations of the 1994 review have been adopted, albeit at varying levels, and that there is greater consistency of FeE practice in the organisation currently rather than prior to the 1994 project. The following recommendations of the 1994 FeE project appear to have been implemented by the majority of respondents: use of a criterion-referenced approach based on the physical demands and physical work categories from the DOT, use of a combination of the psychophysical, biomechanical and physiological models to determine performance in the FeE, tailoring of the FeE to the client's job or vocational goal and use of a standard report format. Although the report samples were provided voluntarily and therefore self-selected by the therapists, there was evidence of some consistency in the headings used and the topics covered. The variation in the lengths, however, was indica-
tive of the variety in report-writing practice overall. In terms of the minimum requirements for FeE reports suggested by Vasudevan (1996), the sample reports provided appear sound. These requirements include reporting of observations about the person's motivation, consistency of performance, pain behaviours, safety of function, and specific abilities and deficits (Vasudevan, 1996). In terms of the model of evaluation, it appears that therapists are using a combination of the models, as recommended. The focus group discussion revealed that the psychophysical model, that is, the person's perceptions of their capacities, is given the ultimate credence in practice. This may be substantiated, in the case of clients with chronic back pain at least, by the strong evidence for psychosocial rather than physical factors predicting eventual outcome, including return to work (Gallagher et aI., 1989; Milhous et aI., 1989; Eklund, 1992; Frymoyer, 1992; Lancourt and Kettelhut, 1992). However, support for the use of the combination of models is evidenced by a recent comparison of perceived vs. observed capacity in a FeE by subjects with low back pain (Piela et aI., 1996). The results found a tendency for overestimation of lifting capacities and underestimation of standing tolerance, supporting use of observation of function rather than self-report alone (Piela et aI., 1996). The Borg Rating of Perceived Exertion (RPE) scale (Borg, 1982) has been used in evaluations to quantify the person's perceptions of their exertion (Jacobs et aI., 1988; Bhambani et aI., 1994; Matheson et aI., 1995) and may provide a quantifiable way of measuring psychophysical aspects of performance during the FeE. The practice of regular rating of subjective pain intensity throughout the FeE may be of questionable benefit, at least for assessing the person with chronic pain (Rudy et aI., 1996). This practice may negatively influence such a person's performance and may not provide a true indication of actual function (Rudy et aI., 1996). With regards to use of the physiological model, the use of heart-rate and blood-pressure monitoring by the therapists appears limited. This is not surprising as it is a relatively new development in FeE and specific guidelines for its use are not widely available. Training in the use of
L. Gibson,l Strong / Work 9 (1997) 3-11
the equipment and clearer guidelines for endpoints appears to be indicated. The primary reason for heart-rate and blood-pressure monitoring is precautionary, as individuals with disabilities or injuries can have poor levels of cardiorespiratory fitness and therefore require at least heart-rate monitoring during FCEs (Bhambani et aI., 1994). The use of heart-rate monitoring only if there is a history of cardiac problems is contrary to the recommendations of the FCE report, which recommended that evaluation of such clients is contraindicated in settings where there is no access to resuscitation equipment or personnel (Gibson 1994, unpublished manuscript). This is consistent with recommendations by Matheson et aI. (1995), who exclude testing of individuals on the EPIC Lift Capacity test who have known risk factors, without appropriate medical supervision and emergency response capabilities (Matheson et aI., 1995). Matheson et al. (1995) also use an upper limit of 85% of maximum heart rate for age (that is, 85% of 220 - age), as do other published accounts of lifting protocols (Mayer et aI., 1988; Hazard et aI., 1993) as a point for ceasing the evaluation. In an overview of the EPIC Lift Capacity (ELC) test, Matheson (1995) also described additional protocols for measuring physiological indicators of performance. These include guidelines for evaluation of individuals using heart rate-limiting medications. More research is required to establish clearer guidelines for heartrate and blood-pressure monitoring in terms of end-points for FCE. Although the therapists who participated in the study expressed concerns about consistency across raters and in determinations made from the FCEs, there appears to be greater consistency of FCE practice in the rehabilitation provider than prior to the project. Inter-rater reliability and predictive validity need to be established through formal research. There is a need to standardise the parameters of the determinations made from an FCE and examine the reliability of these determinations between assessors (Lechner et aI., 1991). Predictive validity of FCEs, probably the most important validity (Macdonald, 1992), remains to be established. Such validity needs to be determined by initially specifying the level of work a
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person can perform (e.g. sedentary, light, medium or heavy), then seeing if they successfully do this on return to work (Lechner et aI., 1991). Actual performance on the job would be the 'gold standard' for validity testing. In terms of practicality and utility, the recommended approach appears to have some support. A criticism of the approach was the lack of normed data for the evaluation. Norm-referenced testing compares an individual's performance against that of a representative sample of people (Rothstein, 1985). To be confident of such a comparison, the sample must be specific to the population being tested, not only in terms of geographicallocation (Macdonald, 1992) but also variables such as disability type (Mathiowetz, 1993) and fitness level (Macdonald, 1992). The value of norm-referenced testing for FCE is questionable. Even if population-specific norms were available, their value in relating the person's performance to actual job demands is limited. Another perceived need amongst the therapists was for more formal testing of effort in the FCE. Procedures for testing whether the person provides full effort, called sincerity of effort or maximum voluntary effort testing, have been described in detail (Matheson, 1990). Use of the coefficient of variation (standard deviation divided by the mean) on tests designed to test voluntary maximal effort has been advocated (Matheson, 1990). Recent research of coefficient of variations on different isometric tests which found differences between tests has cautioned against the sole use of the coefficient of variation (Simonsen, 1995) for assessment of sincerity of effort. Examination of a commonly advocated technique using the curve shape of grip strength measurements on a dynamometer (Stokes, 1983) found that genuine weakness of grip can effect the curve shape (Hamilton Fairfax et aI., 1994). The authors cautioned about the use of this method as an indicator of sincerity of effort. A review of trunk strength testing using iso-machines by Newton and Waddell (1993) did not support their use for assessment of effort. In an examination of psychological factors and maximal effort of subjects with low back pain during a FCE, Kaplan et aI. (1996) found submax-
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imal effort, as measured by the three methods of maximal effort testing, was associated with higher reported depression, perceived disability and anxiety and lower scores on perceived self-efficacy for performing the FCE and for return to work. These authors recommended thorough assessment of such psychological factors prior to a FCE. Particularly for the person with chronic pain, the use of a more cognitive-behaviourally oriented model for FCE has been advocated (Rudy et al., 1996). Use of reliable and valid measures of subjective data such as perceived capacity and self-efficacy, which may explain the discrepancy between actual and perceived function, has been reCommended (Papciak and Feuerstein, 1991; Gibson and Strong, 1996; Kaplan et al., 1996; Rudy et al., 1996). Similarly, Lechner et al. (1991) called for formal quantification of the person's perception of the tasks in FCE, such as the perceived effort to perform the task, the perceived difficulty of the task and the perceived importance of the task to the person's work situation. There are many issues surrounding FCE and its use in disability evaluation and occupational rehabilitation (Abdel-Moty, 1996; Vasudevan, 1996) which need to be considered, including the influence of behavioural and environmental factors (Velozo, 1993; Rudy et al., 1996). Greater consideration of workplace factors and their influence on return to work is required (Feuerstein and Thebarge, 1991; Velozo, 1993; Rudy et al., 1996). Further research and debate is needed to clarify the many issues and improve practice. In addition to the much called for research into the reliability and validity of FCE procedures, examination of the comparative predictive power of perceived capacity and observed capacity for work would be valuable. Acknowledgements
The authors gratefully acknowledge the therapists who participated in the study and the management of the Commonwealth Rehabilitation Service, Queensland for their support of this research.
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