Population aging and hospitalization for chronic disease in Germany

Abstract

Background: The population of Germany is aging, i.e., the elderly currently make up an increasing percentage of the population from year to year. Furthermore, many common chronic diseases mainly affect the elderly. For these two reasons, the overall cost of health care in Germany is expected to increase. We studied the effect that population aging has had on the number of hospitalizations for major types of chronic disease in Germany since the year 2000.

Methods: This study is based on nationwide hospitalization statistics, classified by diagnosis, that were published by the German Federal Statistical Office. We analyzed data for three classes of diagnoses--malignant neoplasia, cardiovascular diseases, and diseases of the musculoskeletal system and connective tissue--which were further broken down into nine diagnostic subgroups. Changes in inpatient case numbers might be due either to population aging or to changing rates of hospitalization for individual diagnoses. We used index decomposition analysis to determine the relative influence of these two factors on changing case numbers.

Results: The author found that the aging of the population increased the number of hospitalizations for all of the diagnoses studied. This was particularly evident with respect to the large birth cohorts born in the 1920s (with the diagnosis of congestive heart failure) and in the period 1934-1944 (with the diagnoses ischemic heart disease, lung cancer, colorectal cancer, and osteoarthritis). On the other hand, changing rates of hospitalization for individual diagnoses increased the number of hospitalizations for some diagnoses (congestive heart failure, diseases of the spine and back) and decreased it for others (ischemic heart disease, cerebrovascular diseases, colorectal cancer, breast cancer).

Conclusion: The aging of the population and the changing rates of hospitalization for various diagnoses are exerting separate effects on the number of hospitalizations for chronic diseases in Germany. Predictions of hospital case numbers in the future must take both factors into account.

Figure 1

Number of hospital treatments (ICD-10 codes A00 to T98) by age group in 2000 and 2009: men

Figure 2

Age-standardized treatment rates for the diagnoses ICD-10 I63 and I64 in 2000 and 2009 (cases per 100 000 inhabitants, standardized by age, old European standard population)