The Impact on Health Outcomes and Healthcare Utilisation of Switching to Generic Medicines Consequent to Reference Pricing: The Case of Lamotrigine in New Zealand

摘要

Background Many countries have implemented generic reference pricing and substitution as methods of containing pharmaceutical expenditure. However, resistance to switching between medicines is apparent, especially in the case of anti-epileptic medicines.Objectives This study sought to exploit a nation-wide policy intervention on generic reference pricing in New Zealand to evaluate the health outcomes of patients switching from originator to generic lamotrigine, an anti-epileptic medicine. Methods A retrospective study using the national health collections and prescription records was conducted comparing patients who switched from originator brand to generic lamotrigine with patients who remained on the originator brand. Primary outcome measures included switch behaviour, changes in utilisation of healthcare services at emergency departments, hospitalisations and use of specialist services, and mortality.