Incidence of low back pain and pre-placement x-ray screening.

The primary purpose of pre-placement back x-ray screening is to reduce the incidence of low back problems. This study was designed to address the specific question of whether or not this objective is achieved, without directly looking at the predictive value of radiological abnormalities of the lumbar spine. Two retrospective cohorts of steelworkers were identified: one group hired before, and one after, introduction of back x-rays into an otherwise identical pre-placement medical examination. The two cohorts were stratified by age and work activity, and by use of a modified life table method were followed for 12 years. All health incidents, modified work, lost time, or permanent job changes were noted. Analysis revealed no statistically significant differences between cohorts for the parameters studied. The inclusion of low back x-ray screening into a comprehensive pre-placement medical examination had no significant effect on the subsequent incidence of low back pain in the cohort of steelworkers studied.