The use of retirees to evaluate occupational hazards. II. Comparison of cause specific mortality by work area

Abstract

This article compared the results of mortality studies in three work areas of the steel industry for the total cohort of workers and for the retirees. This was done to determine further the usefulness and the limitations of retiree studies for occupational mortality studies. The major findings are: 1. Retiree studies detect occupational hazards such as respiratory cancers and nonmalignant respiratory diseases, although the estimated average relative risk will tend, for obvious reasons, to be greater than for the total cohort. 2. Some problems associated with the use of retirees for occupational mortality studies were also discussed. These problems included small sample sizes, the retiree study not indicating significant excess deaths from certain diseases because the excess mortality took place in the younger ages, and differences between the estimates of risk for the retiree study and the total cohort study. 3. The estimates of risk for the studies using all men over age 65 did not vary from the estimates of risk for the total cohort as much as the risks from the retirees did. However, other than the variation seen in the estimates of risk, the exclusion of nonretirees from the retiree study did not seem to affect the overall conclusions. Based on the findings of this study, it was concluded that retiree studies may sometimes be useful tools in detecting occupational hazards when cost and time definitely preclude more comprehensive studies, but that one should be aware of the greater possibility of spurious negative findings due to the limited age group being studied and the smaller sample sizes.