Top-Up Design and Health Care Expenditure: Evidence from Cardiac Stents

Since 2006, Taiwan's National Health Insurance (NHI) covers the full cost of baseline treatment in cardiac stents (bare-metal stents, BMS), but requires patients to pay the incremental cost of more expensive treatments (drug-eluting stents, DES). Within this "top-up" design, we study how hospitals respond to a 26% cut of the NHI reimbursement rate in 2009. We find hospitals do not raise the DES prices from patients, but increase BMS usage per admission by 18%, recouping up to 30% of the revenue loss in 2009-2010. Overall, the rate cut is effective in reducing NHI expenditure despite hospitals' moral hazard adjustment.