Effect of age, gender, ethnicity, socioeconomic status and region on dispensing of CVD secondary prevention medication in New Zealand: the Atlas of Health Care Variation CVD cohort (VIEW-1)

Abstract

There is good evidence to support the use of blood thinning, blood pressure (BP)-lowering, and cholesterol lowering statin medications to improve outcomes in patients with established atherosclerotic cardiovascular disease (CVD). In this national NZ study which included 86,256 patients with CVD in 2011 we found that there was significant under-utilisation of safe and inexpensive secondary prevention medication, particularly in younger people and women. This provides an opportunity to improve CVD outcomes in this easily identifiable high-risk population. Making the gaps in evidence-based practice visible to patients, health providers and health administrators is a critical first step. The data has been made available to the public and medical community in an interactive mapping tool as part of the Health Quality and Safety Commission’s New Zealand Atlas of Health Care Variation (http://www.hqsc.govt.nz/our-programmes/health-quality-evaluation/projects/atlas-of-healthcare-variation/cardiovascular-disease/). Abstract Aim Triple therapy with anti-platelet/anti-coagulant, blood pressure (BP)-lowering, and statin medications improves outcomes in atherosclerotic cardiovascular disease (CVD). However, in practice there is often a substantial evidence–practice gap, with sub-optimal initiation and longer-term adherence. Our aim was to enumerate a contemporary national cohort of people with significant CVD and report the variation in CVD secondary prevention dispensing by demographic variables. Method Using anonymised linkage of national data sets, we identified 86,256 individuals, alive and residing in New Zealand at the end of 2010, aged 30–79 years who were hospitalised for an atherosclerotic CVD event or procedure in the previous10 years. This cohort was linked to the national pharmaceutical dispensing dataset to assess dispensing of CVD prevention medications during the 2011 calendar year. Adequate dispensing was defined as being dispensed a drug in at least 3 of the 4 quarters of the year. Multivariate regression was used to identify independent predictors of adequate dispensing. Results 59% were maintained on triple therapy, 77% on BP-lowering medication, 75% on anti-platelet/anti-coagulants and 70% on statins. From multivariate analysis, patients less than 50 years were about 20% less likely than older patients and women were 10% less likely than men to be maintained on triple therapy. Indian patients were about 10% more likely to be maintained on triple therapy than NZ European/Others. Those living in the Southern Cardiac Network region of New Zealand had slightly higher rates of triple therapy than National Cardiac Regions further north. Conclusion The significant under-utilisation of safe and inexpensive secondary prevention medication, particularly in younger people and women, provides an opportunity to improve CVD outcomes in this easily identifiable high-risk population.