Criterion-related validity of functional capacity evaluation lifting tests on future work disability risk and return to work in the construction industry.

OBJECTIVES: To assess the criterion-related validity of the five Ergo-Kit (EK) functional capacity evaluation (FCE) lifting tests in construction workers on sick leave due to musculoskeletal disorders (MSDs).
METHODS: Six weeks, 6 months and 1 year after the first sick leave day due to MSDs, construction workers underwent two isometric and three dynamic EK FCE lifting tests, and completed the Instrument for Disability Risk (IDR) for future work disability risk. Concurrent and predictive validity were assessed by the associations between the scores of the EK FCE lifting tests and the IDR outcomes (Pearson Correlation coefficients (r) and associated proportions of variance (PV) and area under receiver operating characteristic curve (AUC)). Predictive validity of the EK FCE lifting tests on the total number of days on sick leave until full durable return to work (RTW) was also evaluated (Cox regression analysis).
RESULTS: Concurrent validity with future work disability risk was poor for the two isometric EK FCE lifting tests (-0.15<or=r<or=0.04) and moderate for the three dynamic EK FCE lifting tests (-0.47<or=r<or=-0.31). Only the carrying lifting strength test showed moderate and acceptable predictive validity on future work disability risk (r = -0.39; AUC = 0.72). Cox regression analyses revealed that two out of the five EK FCE lifting tests predicted durable RTW significantly, but only weakly.
CONCLUSIONS: Criterion-related validity with future work disability risk was poor for the two isometric EK lifting tests and moderate for the three dynamic lifting tests, especially the carrying lifting strength test. Predictive validity on durable RTW was poor, although weakly significant in two dynamic EK FCE tests, of which one was the carrying lifting strength test.