Use of death certificates in epidemiological studies, including occupational hazards: variations in discordance of different asbestos-associated diseases on best evidence ascertainment.

There is extensive information on discordance in general between accuracy of medical diagnoses on death certificate categorization of cause of death and available clinical and histopathological data. This is as true for occupational disease as for other conditions. But occupational illnesses bear a special problem. Discordance is not equal across the board--it may vary with each occupationally related disease, and no single formula can be applied. It may be high for angiosarcoma and low for acute hydrogen sulfide poisoning, low for bladder cancer, high for unsuspected methyl mercury poisoning. We have found that for one agent--asbestos--there were different rates of discordance for different asbestos-related diseases (e.g., lung cancer, mesothelioma, asbestosis, kidney cancer) among 4,951 deaths studied prospectively from 1967 to 1986. Caution is therefore required before accepting generalizations concerning (unstudied) discordance in occupational mortality studies, and in their use in risk assessment models.