Survival Analysis for Prognostic Factors of Occupational Low Back Pain

ABSTRACT

PURPOSE: The goals of this research are to find out factors influencing the duration of work-related disability and to present implications for policies to prevent delayed recovery. METHOD: The subjects of this study were 238 workers who had been proved to be industrial disaster victims for occupational low back pain between January 1 2000 and December 31 2003. Kaplan-Meier method was used to estimate the proportion of duration of disability associated with low back pain, and Cox proportional hazards analysis was used to identify factors predicting it. The model distinguished main symptom variables affecting acute(90 days). RESULT: Fifty percent of the workers had not recovered in 408 days. The results of Cox regression show that delayed duration of disability was predicted by diagnosis, pain radiation (in chronic phase), sex, the size and labor union of the workplace, scheduled rest, compensation from the company, and operation. CONCLUSION: Duration of disability associated with compensated low back pain is influenced not only by factors related to the company and compensation system but also by individual factors. Thus, future efforts to reduce duration of disability may need to take into account all these factors.