Microscopic haematuria as a predictor of urological diseases among steel workers.

A cohort of 501 workers in a steel mill in Ontario, Canada was followed up from 1974 to 1986 for 13 years. Results indicate that the 13-year cumulative incidence of urological diseases among workers who had a positive urinalysis result of microscopic haematuria at the beginning of the follow-up period (1974) was 1.3 times that of those who had a negative urinalysis result (95% confidence interval 0.6-2.8). This relative risk remained the same after adjusting for age and smoking. This indicates that there is a possibility that urinary screening for microscopic haematuria could be a useful predictor of urological disease occurrence. However, the benefits of early detection and management were difficult to demonstrate. Serious urological diseases, particularly urinary cancers, were not detected earlier as a result of the urinary screening test in this study. Several studies have been done to validate the test in the past. More work to validate the test and to determine the predictive accuracy is recommended.