Mortality data collection by local authorities compared to a cancer registry

BACKGROUND: Mortality data, i.e., information on whether individuals are living or dead and the causes of death, provide essential endpoints for the assessment of disease progression in clinical-epidemiological studies. In Germany, mortality data for scientific research are often available only through municipal offices, and rarely from registries. In this study, we collected and compared mortality data from these two sources. METHODS: As part of a study on the early detection of lung cancer and pleural mesothelioma, we collected mortality data on patients recruited in 2014-2015 and on control subjects in the general population. These data were obtained from registration and public health offices and (except for the control subjects) through record linkage with the Cancer Registry North Rhine-Westphalia. RESULTS: 448 of the 460 patients consented to follow-up via the cancer registry, and 429 consented to municipal-office-based follow up, as did 197 of the 207 control subjects. Much more effort was needed to collect data from municipal offices than through record linkage with the cancer registry. Over a 5-year period, the percentage of deaths recorded was slightly higher when assessed with data from the cancer registry (51.1% versus 49.7%). Further information on the causes of death was more frequently available through the cancer registry (98% versus 84%). CONCLUSION: Follow-up data from the cancer registry were generally more informative, and required less organizational effort to collect, than data from municipal offices. Obtaining data from cancer registries is, therefore, preferable for future cancer studies, although nationwide registry structures for mortality data are still lacking.