Construct Validity of Functional Capacity Evaluation Lifting Tests in Construction Workers on Sick Leave as a Result of Musculoskeletal Disorders

Objectives: To assess the construct (discriminative and convergent) validity of 5 Ergo-Kit (EK) functional capacity evaluation (FCE) lifting tests in construction workers on sick leave as a result of musculoskeletal disorders (MSDs). Design: Cross sectional within-subject design. Setting: Occupational health service for the construction industry. Participants: Male construction workers (N = 72) on 6-week sick leave as a result of MSDs. Interventions: Not applicable. Main Outcome Measure: After being assessed on 5 EK FCE lifting tests, participants were asked to complete the Von Korff questionnaire on pain intensity and disability as a result of MSDs and the instrument for disability risk assessing the risk for work disability. Discriminative validity was evaluated by comparing the results of the EK FCE lifting test scores between the 2 groups of participants based on the instrument for disability risk scores (high risk for work disability compared with low risk for work disability). Convergent validity was evaluated by assessing the associations between the results of the EK FCE lifting tests and Von Korff questionnaire self-reported pain intensity and disability as a result of MSDs. Results: The hypothesized differences between both instrument for disability risk groups on the 5 EK FCE lifting tests were found in the expected direction but were not statisfically significant (1 test exhibited a trend). Pearson correlation coefficients showed a poor convergent validity between the scores of the Von Korff questionnaire and the EK FCE lifting tests (-.29 <= r <=.05). Conclusions: Poor construct validity of the 5 EK lifting tests was found: discriminative validity was not statistically established, and convergent validity with self-reported pain intensity and disability was poor