The effects of reduced copayments on discontinuation and adherence failure to statin medication in Australia

Abstract

This paper assesses whether the concession card, which offers discounted out-of-pocket costs for prescription medicines in Australia, affects discontinuation and adherence to statin therapy. The analysis uses data from the Australian Hypertension and Absolute Risk Study (AusHEART), which involves patients aged 55 years and over who visited a GP between April and June 2008. Socioeconomic and clinical information was collected and linked to administrative data on pharmaceutical use. Patients without a concession card were 63% more likely (hazard ratio (HR) 95% confidence interval (CI): 1.14-2.33) to discontinue and 60% (odds ratio (OR) CI: 1.04-2.44) more likely to fail to adhere to therapy compared to concessional patients. Smokers were 2.12 (HR CI: 1.39-3.22) times more likely to discontinue use and 2.23 (OR CI: 1.35-3.71) times more likely to fail to adhere compared to non-smokers. Patients who had recently initiated statin medication were also 2.28 (HR CI: 1.22-4.28) times more likely to discontinue use. In conclusion, higher copayments act as a disincentive for persistent and adherent use of statin medication.