BACKGROUND: Successful management of workers on sick leave due to low back pain depends on the identification by the occupational physician of modifiable prognostic factors in the early phase of sick-leave. The prognostic value of factors which influence the course of low back pain and return to work in occupational health care is unclear.
METHODS: Secondary data analysis in a cohort of 299 workers on sick leave between 3 and 6 weeks due to low back pain was applied. We investigated the association of a broad set of prognostic indicators related to characteristics of worker, job, low back pain and psychosocial issues on return to work lasting at least 4 weeks (lasting-RTW) and minimally 1 day of first return to work (first-RTW). Relationships were studied using Cox regression analysis and covered a follow-up period of 12 months. The explained variation of the models was also calculated.
RESULTS: The median time to return to work using lasting-RTW and first-RTW was 76 and 71 days respectively. In addition to individual analysis of potential predictive factors a backward selection procedure resulted in the following multivariable model: self-predicted timing of return to work, pain intensity, job satisfaction, social support, pain radiation, expectations of treatment succes of the occupational physician. Similar results were found for first-RTW. The explained variance of the multivariate model of lasting-RTW was 18%.
CONCLUSIONS: Factors concerning the expectations and beliefs of the worker affected the RTW process. Knowledge of these factors by the occupational physician in the early phase of low back pain and sick-leave may contribute to solutions to promote return to work.