Reimbursement changes and drug switching: are severe patients more affected?

OBJECTIVES: To examine the long-term effects of drug reimbursement adjustments on drug-switching decisions and to investigate whether patients with complicated or severe conditions are more affected.

METHODS: A population-based, longitudinal study with a before-and-after design. Analysis of 141,703 patients with type 2 diabetes covered by the universal health insurance program in Taiwan. Observation of five 6-month phases before and after a drug reimbursement adjustment implemented in October 2009. Drug switching was defined as a brand change within the same anatomical therapeutic chemical group between two consecutive physician visits. Generalized estimating equations were employed to control for the random subject effect.

RESULTS: The drug-switching rates in the five phases were 10.85% and 13.71% before implementation and 31.53%, 28.29% and 15.61% after implementation. Results from the regression model revealed a higher likelihood of receiving switched drugs in phases 3, 4 and 5, with odds ratios of 3.16, 2.72 and 1.44 (with 95% confidence interval 3.04-3.29, 2.61-2.84 and 1.38-1.51), respectively, compared with phase 1. Patients with complicated or severe conditions were more likely to have their drugs switched after the reimbursement adjustment.

CONCLUSIONS: The drug reimbursement adjustment under the health insurance program resulted in an increase in drug-switching decisions, and patients were not exempt from medication switching regardless of the complications or the severity level of their illness.