Patients with low back pain not returning to work. A 12-month follow-up study.

STUDY
DESIGN: A prospective study of patients treated with a light mobilization program for long-term low back pain.
OBJECTIVES: To examine whether medical, psychological, or social factors predict failure to return to work within 12 months in the Scandinavian system of compulsory workers' compensation and social insurance, after a light mobilization program administered 8-12 weeks after initial sick leave. SUMMARY OF BACKGROUND DATA: The relative power of predicting factors varies in previous work, and there are no previous data on prognostic factors for light mobilization programs.
METHOD: Patients (n = 260) on sick leave for 8-12 weeks for low back pain were examined with a battery of psychological and medical tests, before entering a light mobilization program. The treatment was given regardless of radiographic or clinical findings. The patients were encouraged to be active participants in the management and prevention of their back pain. Their sick leave status then was checked through registers 12 months after they had entered the treatment program.
RESULTS: For those not returning to work within 12 months (23%), only combined models had acceptable predictive power (77%; discriminant analyses). Dominant variables were low Internal Health Locus of Control Score, restricted lateral mobility, and reduced work ability. The predictive value of each set of variables, taken alone, was significant only for medical variables (67% correct prediction).
CONCLUSIONS: The final discriminant function may have potential as a brief screening instrument for the number of patients with low back pain who do not benefit from the light mobilization program.