OBJECTIVES: Hypertension is a chronic disease for which only 68% of treated patients were controlled in Canada in 2013. Pharmacists in the province of Québec recently received legislative authority to adjust the dosage of antihypertensive drugs if there is an agreement with the prescriber on the therapeutic target. This research aims to estimate the incremental cost-utility ratio (ICUR) of this new model of care in Québec.

METHODS: A Markov model was developed to extrapolate the impact of this pharmacy practice on strokes, myocardial infarctions and mortality. The model used 1-year cycles over a lifetime horizon. Framingham Risk Equations were used to derive the impact of blood pressure control on strokes and myocardial infarctions. The clinical efficacy of the intervention was derived from the RxAction clinical trial which was conducted in Alberta where pharmacists have a practice similar to Québec’s one. Efficacy was expressed as the proportion of patients with controlled blood pressure. The payer perspective was adopted and only direct costs were included. The main outcome was expressed as the number of quality-adjusted life years (QALYs) gained. Both QALYS and costs were discounted at a 1.5% annual rate. A cohort of 1000 patients entered the model at 65 years old.

RESULTS: The model yielded 768 more QALYs in the intervention group for an incremental expense of 3,925,576$. The ICUR was 5,111$/QALY. At a willingness-to-pay threshold of 50,000$/QALY, the intervention is cost-effective. The results were sensitive to the comparative efficacy of the pharmacist intervention against usual care and to the utility of hypertension.

CONCLUSIONS: Providing pharmacists the ability to adjust the dosage of antihypertensive drugs within the actual fee-for-service rational appears to be cost-effective. Obtaining data on the efficacy of this pharmacy practice from a trial conducted in Québec would provide better information to inform this economic evaluation.