Functional capacity evaluation (FCE) is a performance measure used widely to make important decisions about the capacity of workers with pain or disability, such as chronic back pain (CBP), to return to work. This use occurs despite limited evidence of the psychometric properties of the various approaches to FCE and the documented need for new models of FCE that address the psychosocial variables known to impact on performance and return to work for people with CBP This thesis reports the research and development of a new approach to FCE that has been developed for use with rehabilitation clients with CBP. This new approach, called the Gibson Approach to FCE (GAPP FCE), has been developed to provide a standard approach to FCE which incorporates measurement of constructs shown to be influential in the occupational performance and return to work of people with CBP It therefore addresses some of the gaps evident in current FCE practice. After reviewing
the evidence for FCE practice, especially for rehabilitation clients with CBP, this thesis presents the research and development of the GAPP FCE, including its planning, construction and quantitative evaluation to date, which has followed standard processes of test development. A rationale for the content of the GAPP FCE is provided, including the key psychosocial variables evaluated in the approach. A review of FCE practice in a rehabilitation provider was conducted to examine issues in practice and to inform the development of the new approach. An initial version of the approach was developed and piloted for its feasibility, with five participants without injury, before use with clients with CBP An expert occupational therapist was trained in the use of the approach and was then silently observed by the candidate administering the approach with five occupational therapy students. This pilot study demonstrated the practical application of the approach and assisted the refinement of
aspects of its administration and scoring. A detailed User's Manual including specifications for each item and comprehensive operational definitions was then written, according to test development standards. Then, a further pilot study was conducted with rehabilitation clients with CBP Two occupational therapists from a rehabilitation provider were trained in the approach. The two trained therapists were silently observed administering the evaluation on a total of five rehabilitation clients with CBP by two expert evaluators. The findings of this pilot study confirmed the promise of the approach with clients with CBP in an applied setting. The GAPP FCE was then reviewed by five expert occupational therapists for aspects of face and content validity, safety, reliability, sensitivity, practicality, utility and technical quality. The experts gave support to most aspects of these test criteria and overall support to the approach as an innovative, safe, and useful approach to FCE.
Particular support was given to the inclusion in the GAPP FCE of evaluation of the psychosocial aspects of performance, and the provision of a guiding framework for evaluating the three main models of FCE, that is, the biomechanical, physiological and psychophysical. After further revisions, the revised GAPP FCE was then trialed again with rehabilitation clients with CBP, to provide a preliminary examination of the inter-rater reliability, safety, practicality and utility of the revised approach. Eleven occupational therapists were recruited and trained in the approach, then silently observed by either one of the other trained therapists, or the candidate, or both, while administering the GAPP FCE with clients with CBP referred to them for FCE. Fourteen FCEs were conducted and silently observed. This trial provided further evidence for aspects of the safety, reliability, validity, practicality and utility of the approach. Preliminary support was found for the inter-rater reliability
of the main overall ratings of RTW made from the revised GAPP FCE and for some of the items, especially between an experienced occupational therapist and the candidate. The ongoing issues with some aspects of the approach and indications for further research and development are discussed. The future of the GAPP FCE is discussed within the context of broader issues of the conceptual focus of FCE and the future of FCE practice in general in work rehabilitation.