Deductibles and health care expenditures: empirical estimates of price sensitivity based on administrative data.

Objective: To estimate the price sensitivity of demand for health care by analysing the relation between deductibles and expenditures found in an administrative database.

Data: Data are from 100,048 privately insured in the Netherlands. Information is available on expenditures in 1996, demographic variables, deductibles, and both diagnoses from hospitalisations and pharmacy costs for the years 1993-1995. The data are unique because prior pharmacy costs are good predictors of future expenditures while in the three years concerned these costs were covered by a separate national, mandatory insurance scheme. Therefore, these costs are not affected by deductibles and can be seen as excellent proxies for health status, which this study uses to correct for the existing adverse selection with respect to the choice of deductible.

Methods: For the group of insured without deductibles an expenditure model is estimated which is subsequently used to estimate expected expenditures for insurance policies with various levels of deductible. From the difference between actual and expected expenditures the impact of deductibles on expenditures is estimated, and from this price sensitivity.

Results: The principal finding is an estimated price elasticity of -0.14. The highest price sensitivity is found for GP care (-0.40) and physiotherapy (-0.32), and the lowest for specialist care (-0.12) and prescription drugs (-0.08); hospital care was hardly affected.