Changes in drug utilization following the outpatient prescription drug cost-sharing program - evidence from Taiwan's elderly

This paper examines changes in drug utilization following Taiwan's newly implemented National Health Insurance (NHI) outpatient prescription drug cost-sharing program for persons over 65 years old. The study is a hospital outpatient prescription level analysis that adopts a pretest-posttest control group experiment design. Selected measures of outpatient prescription drug utilization are examined for cost-sharing and non cost-sharing groups in cost-sharing periods and pre cost-sharing periods. Additional analyses were conducted comparing older patients with and without chronic diseases and differences for essential and non-essential drugs. Patients over age 65 were drawn from 21 hospitals in the Taipei area using a stratified random sampling method. This paper yields several interesting findings. First, average prescription cost and prescription period increased for both the cost-sharing and non cost-sharing groups. However, the rate of increase was significantly less in the cost-sharing group when compared with the non cost-sharing group. Second, the elderly with non-chronic diseases were more sensitive (i.e., reducing drug utilization) to the drug cost-sharing program when compared with those with chronic diseases. Third, for the elderly with non-chronic diseases average drug cost per prescription experienced a smaller decrease in essential drugs but a moderate increase in non-essential drugs for the cost-sharing group. By contrast, for the non cost-sharing group, average drug cost per prescription increased sharply in non-essential drugs as well as essential drugs. Finally, there was a significant increase in the number of prescriptions as well as drug costs above the upper bound of the cost-sharing schedule. The outpatient drug cost-sharing program implemented by the NHI in Taiwan did not reverse the trend of prescription drug cost increases in hospitals. The significant increase in the number of prescriptions above the upper bound of the cost-sharing schedule implies that the NHI should increase the upper bound. Further analysis needs to evaluate any adverse clinical impact for older patients resulting from policy changes. (C) 2004 Elsevier Ireland Ltd. All rights reserved.