Risk of long-term disability among patients with back pain.

The aim of this study was to find predictors of length of time on sick-leave and the change in sick-leave as a result of intervention. Many studies of back pain show that medical and psychosocial factors covary with length of sick-leave. The results are based on the questionnaire responses of 240 patients. A stepwise multiple regression showed that the significant predictors of number of sick-days the year after intervention were the number of sick-days before the intervention and also hypochondria. Significant predictors of sick-leave change were sleep disturbance and number of sick-days before intervention. A discriminant function analysis comparing a group that had decreased its sick-leave with one that had increased its sick-leave showed 7 predictors of increased sick-leave: high risk of somatisation; many children and family members living at home; a change in tasks at work owing to pain; brothers and sisters with longstanding pain problems; frequent pain, and sleep disturbance. It is important for physiotherapists to enquire about patients' earlier sick-leave patterns in order to identify risk factors for long-term disability among patients with back pain. Some of these factors have been identified in this study.