The effect of reinsuring a deductible on pharmaceutical spending: A Dutch case study on low-income people

Many countries have cost sharing schemes in health insurance to control health care expenditures. The Dutch basic health insurance includes a mandatory deductible of currently 385 euros per adult per year. To avoid affordability problems, several municipalities offer a group contract for low-income people in which the mandatory deductible is 'reinsured'. More specifically, this means that out-of-pocket spending under the deductible is covered by supplementary insurance. By comparing groups with and without the reinsurance option, this study examines whether low-income people are price-sensitive when it comes to pharmaceutical spending. We use a unique dataset from a Dutch health insurer with anonymized individual insurance claims for the period 2014-2017. The data allows for a clean difference-in-difference analysis as it contains both municipalities without reinsurance and municipalities that introduced reinsurance on January 1st 2017. We find that the introduction of reinsurance led to a statistically significant increase in pharmaceutical spending of 16% in the first quarter of 2017 and 7% in the second quarter. For the second half of 2017 the effect is small and not statistically significant. This study adds to the evidence that low-income people are indeed price-sensitive when it comes to pharmaceutical spending.