Severity of silicosis at compensation between medically screened and unscreened workers.

Abstract

Most developed countries have medical surveillance programs for some of the workers (typically miners) exposed to silica, but the impact of these programs is not documented. Clinical data from 1388 compensated silicotic workers in Quebec, Canada, were used. The severity of disease at compensation was compared between workers in the surveillance program and those who were not. Predicted vital capacity at less than 80% at compensation was less likely among workers under surveillance than among those who were not (odds ratio = 0.59; 95% confidence interval 0.44-0.80); the occurrence of a radiological image with large opacities and profusion of category 1/1 or more was also less likely in the group with surveillance (odds ratio = 0.60; 95% CI = 0.39-0.92). The data indicate a benefit from medical surveillance but alternative explanations are discussed.