Sources of Data
Table of Contents
The official cause-of-death statistics underlying the mortality data are based on official death certificates filled out in accordance with WHO international standards. After the death certificate is filled out by a physician, it is forwarded through the community records office and health office to the appropriate state-level statistical bureau. There the cause of death is coded according to the current ICD revision and assigned to the community in which the deceased person last resided. Then, in several states, the death certificate is returned for permanent filling to the health office of the community in which the person died; in other states it is returned to the health office of the community in which the deceased last resided.
The diseases stated as the cause of death on official death certificates are coded according to the International Classification of Diseases (ICD) published by the WHO. The following revisions of the ICD have been used in western Germany: the 6th revision from 1952 through 1954, the 7th revision from 1955 through 1967, the 8th revision from 1968 through 1978, and the 9th revision since 1979. All ICD codes referred to in the present atlas are based on the 9th revision of the ICD.
Causes of death in western Germany have always been ICD-coded by specially trained personnel to ensure compliance with uniform standards that do not vary from one state to the next. In the former GDR, by contrast, all coding was done by the physicians who filled out the death certificates. This raises validity problems that are discussed more fully in the section on "Data Quality" below. After reunification, the coding procedures that had been established in western Germany continued to be practiced in both parts of the country.
Population data are based on the 1950, 1961, 1970, and 1987 censuses and on population updates between censuses. Figures on births, deaths, and population movements are also taken into account. Compulsory registration makes it relatively easy to trace population movements within Germany. The calculations of age-standardized mortality rates in the atlas are based upon yearly averages for the population residing in a designated region during a specified period of time.
The text that accompanies and describes each type of cancer states the incidence rates for the year 1989, the final year for which the cancer registry of the former GDR published data. The data for the former GDR are drawn from the Atlas of Cancer Incidence in the GDR for 1961-1989 (Möhner et al. 1994), and data for the old Federal Republic are drawn from the Saarland cancer registry for the 3-year period 1988-1990 (Saarland Statistical Bureau 1992). These publications also contain data from previous years, some useful for determining whether the incidence of a particular cancer is rising, falling, or stabilizing. Whenever such inferences can be drawn, they are noted in the accompanying text.
The absence of a nationwide cancer registry in Germany was mentioned above. Based on available registry data, the Robert Koch Institute (RKI) calculated the projected numbers of new cases of various cancer in Germany for the year 1993 (Schön et al. 1995). Since nationwide cancer incidence is a subject of frequent inquiry, the RKI projections are cited in the text to provide at least a crude impression of cancer incidence on a national scale.
Relative 5-Year Survival Rates
The RKI also made comparisons of relative 5-year survival rates calculated from the data of the cancer registries (Schön et al. 1995). These figures, too, are cited in the text. They are based on cancer cases from the western and eastern registries for the period 1980-1984 and on mortality tables of the former GDR for 1985-1986 and of the Saarland for 1980-1085.