Consequences of cost barriers to prescriptions: cohort study in Aotearoa New Zealand.

Abstract

A NZ$5 co-payment prescription charge was removed in July 2023 but may be reinstated. Here we quantify the health impact and cost of not being able to afford this charge. We linked New Zealand Health Surveys (2013/2014-2018/2019) to hospitalisation data using data available in Integrated Data Infrastructure (IDI). Cox proportional-hazards models compared time to hospitalisation between those who had faced a cost barrier to collecting a prescription and those who had not. Of the 81,626 total survey respondents, 72,243 were available for analysis in IDI. A further 516 were excluded to give an analysis dataset of 71,502. Of these, 5,889 (8.2%) reported not collecting a prescription due to cost in the previous year. Among people who faced a cost barrier, 60.0% (95% confidence interval [CI] 58.7-61.2%) were admitted to hospital during the study period, compared to 43.9% (95% CI 43.6-44.3%) of those who did not. Having adjusted for socio-demographic variables, people who faced a cost barrier were 34% (hazard ratio 1.34; 95% CI 1.29-1.39) more likely to be admitted to hospital than those who did not. Annual avoidable hospitalisation costs-were prescription co-payments to remain free-are estimated at $32.4 million per year based on the assumption of a causal relationship between unmet need for prescription medicines and subsequent hospitalisation. The revenue to the health system from co-payments may be offset by the costs associated with avoidable hospitalisations.