Effects of cost sharing on seeking outpatient care: a propensity-matched study in Germany and Switzerland.

BACKGROUND: Several studies have assessed the effect of cost sharing on health service utilization (HSU), mostly in the USA. Results are heterogeneous, showing different effects. Whereas previous studies compared insurants within one health care system but different modes of insurance, we aimed at comparing two different health care systems in Europe: Germany and Switzerland. Furthermore, we assessed the impact of cost sharing depending on socio-demographic factors as well as health status. METHODS: Two representative samples of 5197 Swiss insurants with and 5197 German insurants without cost sharing were used to assess the independent association between cost sharing and the use of outpatient care. To minimize confounding, we performed cross-sectional analyses between propensity score matched Swiss and German insurants. We investigated subgroups according to health and socio-economic status to assess a potential social gradient in HSU. RESULTS: We found a significant association between health insurance scheme and the use of outpatient services. German insurants without cost sharing (visit rate: 4.8 per year) consulted a general practitioner or specialist more frequently than Swiss insurants with cost sharing (visit rate: 3.0 per year; P < 0.01). Subgroup analyses showed that vulnerable populations were differently affected by cost sharing. In the group of respondents with poor health and low socio-economic status, the cost-sharing effect was strongest. CONCLUSION: Cost-sharing models reduce HSU. The challenge is to create cost-sharing models which do not preclude vulnerable populations from seeking essential health care.