Predictors of annual pharmaceutical costs in Australia for community-based individuals with, or at risk of, cardiovascular disease: analysis of Australian data from the REACH registry.

BACKGROUND: Cardiovascular disease (CVD) remains a leading cause of death across the world and poses a significant economic burden. Research regarding per-person use and cost of cardiovascular pharmaceuticals in Australia, as well as potential predictors of pharmaceutical costs in populations using the 'bottom up' costing approach, is limited. Previous studies have adopted 'top down' costing approaches and have been based largely on hypothetical examples and considered only inpatient settings.
OBJECTIVE: To determine the distribution of pharmaceutical costs (from a governmental perspective) related to each cardiovascular risk factor for individuals with, or at high risk of, CVD by analysing data for Australian participants enrolled in the Reduction of Atherothrombosis for Continued Health (REACH) Registry.
METHODS: 2873 participants were recruited for the REACH Registry through 273 general (primary care) practices in Australia. Included among data collected at baseline was a cardiovascular medicines review. Average weighted costs per person were estimated using Government-reimbursed prices (2007). Annual costs were stratified by sex, age, disease group and other co-morbidities. A multivariate linear regression model was utilized to reveal the predictors of the pharmaceutical costs.
RESULTS: The average annual median cost of cardiovascular pharmaceuticals per person was Australian dollars ($A)1310. Use of lipid-lowering agents, non-aspirin (acetylsalicylic acid) antiplatelet agents and thiazolidinediones (glitazones) added significantly to the average annual per-person costs. The multivariate regression model showed that the predictors of annual pharmaceutical costs were dyslipidemia (beta coefficient value [marginal annual cost associated with a condition] $A691; p < 0.001), hypertension ($A346; p < 0.001), vascular disease ($A340; p < 0.001), diabetes mellitus ($A298; p < 0.001), and obesity ($A52; p = 0.03). The same predictors, together with sex, were shown to have an impact on the number of medicines used.
CONCLUSIONS: Among community-based Australians with, or at risk of, CVD, independent drivers of annual cardiovascular pharmaceutical costs are dyslipidemia (which accounts for half of per-person costs), followed by hypertension, established CVD, and diabetes. Obesity also independently adds to the cost of cardiovascular pharmaceuticals in community-based Australians with, or at risk of, CVD.