Factors influencing results of functional capacity evaluations in workers' compensation claimants with low back pain.
OBJECTIVE
Physical and psychosocial factors are hypothesized to influence performance-based assessment. The purpose of this study was to evaluate the association between performance on the Isernhagen Work System Functional Capacity Evaluation (IWS-FCE) and various clinical and psychosocial factors.


METHODS
The sample consisted of 170 workers' compensation claimants who were undergoing functional capacity evaluations (FCEs) for low back injuries.


METHODS
In this cross-sectional study, claimants completed a battery of work-related measures, including the IWS-FCE, the Pain Disability Index (PDI), a workplace organizational policies and practices scale, and a recovery expectations questionnaire. Functional capacity evaluation performance indicators were the number of tasks in which subjects did not meet work demands and weight lifted on the floor-to-waist lift. Analysis included multivariable regression.


RESULTS
Only the PDI, pain intensity, age, and sex independently contributed to floor-to-waist lift performance. The PDI, pain intensity, and duration of injury contributed to the number of failed tasks.


CONCLUSIONS
The results indicate that performance on FCEs is influenced by physical factors, perceptions of disability, and pain intensity. However, perceptions of workplace organizational policies and procedures were not associated with FCE results for workers' compensation claimants with chronic back pain disability. Functional capacity evaluations should be considered behavioral tests influenced by multiple factors, including physical ability, beliefs, and perceptions.
Gross
Douglas P
DP
Department of Physical Therapy, University of Alberta, 2-50 Corbett Hall, Edmonton, Alberta, Canada T6G 2G4. dgross@ualberta.ca
Battié
Michele C
MC
D000328:Adult; D000367:Age Factors; D002170:Canada; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000523:psychology*; D008297:Male; D015999:Multivariate Analysis; D016134:Organizational Policy; D010147:Pain Measurement; D011594:Psychometrics; D020127:Recovery of Function; D012720:Severity of Illness Index; D012737:Sex Factors; D012944:Social Support; D011795:Surveys and Questionnaires; D014938:Work Capacity Evaluation; D014942:Workers' Compensation