National Mortality Register

Abstract

One additional benefit of the post mortem external examination is to collect valid information about cause of death and to set up a national mortality register. To date, the only German federal state to have established a mortality index for the purpose of epidemiological studies is the city of Bremen (1). Up until now, national epidemiological mortality follow-ups have only been feasible by requesting pseudonymized death certificates from the local public health departments. Because in some German federal states death certificates only need to be kept for a limited period of time (10 years), significant data losses, especially in the case of historical cohorts, may be assumed when follow-ups are based on the individual collection of death certificates (2). To provide reliable follow-up information, not only the death certificate needs to be correctly completed, but the underlying cause of death must also be coded with the correct ICD. Coding is done by coders in the state statistical offices who work according to official coding rules (3). Most coders do not have any specific medical training or education. They learn the coding rules in seminars and regular refresher courses. Notwithstanding, even among experienced coders, differences in coding behaviour arise because of the complexity of the applied rules and the erratic quality of death certificates. In particular, when death certificate entries are ambiguous, coders have to try to interpret the underlying cause of death. This was confirmed in our experience of mortality studies in which coders carried out the reference coding of the cause of death from death certificates. In addition to the specific medical qualification for carrying out post mortem external examinations as proposed in the current political debate, an automated multicausal coding of causes of death, comparable to the existing IRIS program (4), should be required. This would ensure valid, reproducible coding of causes of death. With the concurrent establishment of a national mortality register, an intensification of epidemiological research using mortality data should be expected in Germany, which should also reveal implausibilities in the determination of causes of death. This should also contribute to improved data quality in the cause of death statistics.