Do patient characteristics affect the predictive validity of Functional Capacity Evaluations

The aim of this study was to identify patient-related characteristics that affect the predictive validity of the FCE assessment ELA. A prospective multicenter study was conducted on 303 patients with musculoskeletal disorders (MSD) recruited from eleven rehabilitation centers. The ELA-based estimation of the participants' ability to cope with physical work demands was considered valid if RTW was paired with a positive ELA outcome (≥ moderate) as well as if non-RTW was accompanied by a negative ELA outcome (rather or very poor). In the remaining cases, the ELA result was judged as non-valid. To reduce the risk of false conclusions, the rating was performed inversely in participants that (1) reported severe limitations regarding their productivity at work, (2) attributed RTW to a change in job resp. a reduction of their physical work demands and in those that (3) attributed non-RTW to non-physical reintegration barriers only. Using questionnaires, 28 patient-related characteristics were collected. Logistic regression models were calculated to identify characteristics that affected the predictive validity of ELA. ELA was considered valid in 208 of 303 (69%) participants. A moderate and strong pain-related disability at work were associated with a 0.15-fold (95% confidence interval (95% CI) 0.05–0.46), respectively, 0.19-fold (95% CI 0.05–0.72) chance for a valid outcome. In addition, a negative influence was found in participants that reported psychosocial distress (odds ratio (OR) 0.35; 95% CI 0.15–0.82), a native language different from the national language (OR 0.16; 95% CI 0.05–0.56) as well as in those that expected to return to work, but not within one month (OR 0.17; 95% CI 0.06–0.46). Further variables—including age, employment status, fear-avoidance beliefs and the level of physical work demands—did not affect the predictive validity of ELA. The results suggest that the predictive validity of ELA is primarily limited by patients that report a moderate or strong pain-related disability at work, psychosocial distress as well as the expectation to return to work, but not within one month. Furthermore, a negative influence can be assumed for language barriers.