Evaluation of multiple causes of death in occupational mortality studies.

An exploratory examination of the possibility of using multiple causes of death information from death certificates in mortality studies has been undertaken. The formation of a matrix of primary by contributory causes has been suggested. The matrix gives an overall picture of mortality patterns, serves as a scheme to identify disease combinations, and can be utilized as a data-editing device. From the matrix, several conventional, as well as several new statistics can be computed. The methodology has been illustrated with data from a cohort of steelworkers. The gain in information as a result of routinely recording multiple causes of death has also been discussed.