LOW-BACK-PAIN - PREDICTORS OF ABSENTEEISM, RESIDUAL SYMPTOMS, FUNCTIONAL IMPAIRMENT, AND MEDICAL COSTS IN OREGON WORKERS-COMPENSATION RECIPIENTS

Background Wide variations in disability duration and magnitude have b een noted among recipients of workers' compensation for low back pain. Findings from recent studies have indicated that inclusion of a broad array of variables (i.e., physical, occupation, social, economic) is needed to understand differences in workers' responses to occupational low back pain Methods Workers' compensation and questionnaire data fr om 340 Oregon workers with low back claims were merged to develop mult ivariate models predicting: (1) absenteeism days, (2) residual symptom s, (3)functional impairment, and (4) medical costs. Results Forty-two percent of the variation in low back symptoms was explained by: discon tinuing physical fitness activities post-injury (beta = -.419), self-r eported low energy/high fatigue (beta = -.227), poorer general heath ( beta = .137), and attorney involvement in claim (beta = .117), (adjust ed R-2 = .418, p < 0.001). Survival curves revealed significantly long er claim durations among workers who discontinued physical fitness act ivities post-injury compared with workers who did not; these differenc es remained significant even after controlling for severity of the ini tial injury. Conclusion Continuation of physical fitness activities du ring the recovery process was found to be a significant predictor in t hree of four regression models, providing evidence on behalf of a rela tionship between fitness and positive health outcomes. However it was not possible to clearly differentiate pre-morbid from post-injury fitn ess, nor to determine if this relationship was due to a therapeutic ef fect on the back, the general restorative benefits of remaining active , or represents a proxy variable for workers' self-care efforts during recovery. (C) 1998 Wiley-Liss, Inc.