Do Patients with More Education Receive More Subsidized Dental Care? Evidence from a Natural Experiment Using the Introduction of a School Reform in Norway as an Instrumental Variable

Abstract

Background: In Norway, for several dental conditions, a substantial part of treatment costs are reimbursed by the National Insurance Scheme. Ideally, the probability of receiving subsidized dental care (SDC) should be independent of social determinants of health, such as education, so that dental services are accessible to everyone independent of their social status. Objective: The main objective of this study was to estimate the causal effect of education on the probability of receiving SDC in the adult Norwegian population. Research Design: During the period 1960-1972, all municipalities in Norway were required to increase the number of compulsory years of education from 7 to 9 years. This education reform was used to create exogenous variation in the education variable. Since municipalities implemented the reform at different times, we have both cross-sectional and time series variation in the reform instrument. Thus we were able to estimate the effect of education on the probability of receiving SDC by controlling for municipality fixed effects and trend variables. Subjects: This study included all Norwegian adults, born during the period of 1947-1958. Measures: Information about education (number of years), whether the individuals had received SDC, place of residence (municipality) was collected. Results: The probability of receiving SDC was found to increase by 2 percentage points per additional year of education. Conclusion: People with the most resources benefit the most from a universal welfare scheme that is addressed to reach everybody. We suggest providing information about the subsidy scheme in a way that is easily available and understandable to all individuals, independent of their level of education.