Descriptive study of prognostic factors influencing survival of compensated silicotic patients

The objective of this study was to assess survival and the prognostic influencing survival of compensated silicotic patients. All workers compensated for silicosis in the Province of Quebec from 1938 to 1985 (n = 1,165) were included. Clinical data were those collected during the exam that led to a compensation decision. Due to missing data, a subcohort of 961 patients was used for multivariate analysis of clinical prognostic factors with the Cox proportional hazards model. The following factors made an independent contribution to survival: age at compensation, smoking, dyspnea, expectoration, abnormal breath sounds, radiographic appearance, and vital capacity. On the basis of the model, patients with small opacities alone on their chest radiograph and who did not have dyspnea, expectoration, or abnormal breath sounds had a survival similar to the average Quebec man; other patients had a poorer survival. We conclude that it is possible to identify at the time of compensation, silicotic patients who are likely to have a life expectancy similar to that of the general population. Symptoms and physical signs as well as radiographic and lung function abnormalities appear to be useful prognostic indicators in compensated silicotic patients.