gms | German Medical Science

Background: Analyses of outpatient drug prescription data by age and gender groups using drug prescription data of all statutory health insurance (SHI) insurees or those of individual (types of) health insurances are carried out by different institutions in Germany. Outpatient drug costs for SHI insurees are mostly presented at the level of active ingredients or groups of active ingredients [1]. The question of which drug costs are incurred by the treatment of specific diseases remains a particular challenge. On the one hand, this is due to the fact that the diagnosis triggering the prescription is not documented on the drug prescription forms and, on the other hand, many prescribed drugs are approved for different diseases. The AOK Research Institute (WIdO) has developed an allocation procedure that allows to determine the drug costs of different diseases. This procedure is used in the official health cost accounting of the Federal Statistical Office [2].

Materials and methods: Based on drug-related approved indications and anonymised outpatient claims data for the approximately 26 million AOK drug patients, a drug-disease group matrix was created. The matrix allows to distribute the drug costs for the more than 73 million SHI insurees to the (approx. 140) disease groups used in the disease-related cost accounts of the Federal Statistical Office. Thus, for the reporting year 2020, it was possible to distribute the 46.1 billion euros in net costs to these disease groups.

Classification systems are indispensable instruments for the evaluation of prescription data. The ICD system [3] is used for coding diseases and thus by the prescribing physicians to document the insurees’ diagnoses which are available to the health insurance funds on a quarterly basis for billing purposes. The ATC system with daily doses [1] is available for drug analyses; it is revised and adapted annually for the German market by the WIdO. In order to link both systems and assign drugs (ATC) to diseases (ICD), a three-stage procedure was developed in collaboration with the Federal Statistical Office. This procedure was published jointly by WIdO and Federal Statistical Office in April 2021 with a detailed methodological description, selected results, and discussion regarding the possibilities and limitations arising from the use of the assignment procedure [4].

Results: Almost half of the SHI's outpatient pharmaceutical expenditure is spent on the treatment of cancer, cardiovascular diseases and metabolic diseases such as diabetes. This corresponds to 21.7 billion euros in the 2020 reporting year. With 9.2 billion euros, the treatment of neoplasms accounts for the largest share.

The distribution of expenditure by age and gender of the SHI insurees shows comparatively higher costs for women in the younger age groups and significantly higher costs for men in later years of life. Especially in the older age groups, expenditures are mostly due to the costs of the treatment of neoplasms, which, among other things, occur at different stages of life (and with different frequency), depending on gender. For example, the peak incidence of breast cancer, the most common type of cancer in women, is in the age groups 45 to 65, while in men the most common type, prostate cancer, usually does not occur until an older age [5].

Conclusion: The analysis of outpatient drug costs at the expense of the statutory health insurance system by disease groups allows a differentiated presentation of the differences according to age and gender and allows gender-specific statements. This applies in particular with regard to neoplasms.