The Problem of Repeated Surveys. How Comparable are their Results Regarding the Utilization of Medical Services?

Abstract

Large-scale representative population surveys in Germany contain questions pertaining to health and its determinants as well as the prevalence and intensity of outpatient services utilization. In this chapter, the comparability of the instruments used in these surveys and their results are examined. Questions on in- and outpatient care utilization as well as utilization of preventive services were taken from the public use files (PUFs) of the East-West Health Survey, the 1998 Federal National Health Survey, the 2003 Telephone Health Survey, and the 2009 German Health Update (Gesundheit in Deutschland aktuell GEDA2009). The study also used data from the 26 waves of the Socioeconomic Panel (SOEP, 1984–2009) and the 16 waves of the Bertelsmann Healthcare Monitor (2001–2009) studies. The main result of this comparable study is that the target groups of the Robert Koch Institute (RKI) surveys, the SOEP, and the Bertelsmann Health Monitor differ markedly. Also their questions on outpatient care utilization differ in terms of reference period and types of physicians contacted. Therefore, the results of questions on the use of outpatient care services as well as preventive services are not easily comparable. The surveys’ questions on inpatient care are more comparable. Therefore, there is no unique study which delivers valid reference data on utilization of inpatient, outpatient, and preventive services in Germany. The results of secondary analyses of German statutory health insurance (SHI) claim data could be used to confirm the external validity of the surveys’ results.