Comparison of death certificate occupation and industry data with lifetime occupational histories obtained by interview: variations in the accuracy of death certificate entries.

This study compares usual and recent occupation and industry data from lifetime work histories obtained by interview with death certificate entries for occupation and industry for 2,435 persons diagnosed with cancer. Match rates are calculated as the percent of death certificate occupation and industry entries that were confirmed by interview data and are compared for exact 3-digit 1980 U.S. Census Bureau occupation and industry codes and for groups of these codes. The overall match rate for individual usual occupation codes was 47.9% and for exact usual industry codes it was 61.8%. Significant differences between the interview data for usual occupation or industry and the death certificate entry were observed by race and gender, marital status, number of years worked, and occupation and industry groups and by age for industry. Misclassification or overreporting of occupation and industry data on the death certificate ranged from 30 to 50% in this study. Our results suggest that the utility of death certificate data for investigations into the occupational risk factors for cancer may be quite limited.