Cost-utility analysis of physician-pharmacist collaborative intervention for treating hypertension compared with usual care

Abstract

Objective: To estimate long-term costs and outcomes attributable to a physician-pharmacist collaborative intervention compared with physician management alone for treating essential hypertension. Methods: A Markov model cohort simulation with a 6-month cycle length to predict acute coronary syndrome, stroke, and heart failure throughout lifetime was performed. A cohort of 399 patients was obtained from two prospective, cluster randomized controlled clinical trials implementing physician-pharmacist collaborative interventions in community-based medical offices in the Midwest, USA. Framingham risk equations and other algorithms were used to predict the vascular diseases. SBP reduction due to the interventions deteriorated until 5 years. Direct medical costs using a payer perspective were adjusted to 2015 dollar value, and the main outcome was quality-adjusted life years (QALYs); both were discounted at 3%. The intervention costs were estimated from the trials, whereas the remaining parameters were from published studies. A series of sensitivity analyses including changing patient risks of vascular diseases, probabilistic sensitivity analysis, and a cost-effectiveness acceptability curve were performed. Results: The lifetime incremental costs were $26 807.83 per QALY (QALYs gained = 0.14). The intervention provided the greatest benefit for the high-risk patients, moderate benefit for the trial patients, and the lowest benefit for the low-risk patients. If a payer is willing to pay $50 000 per QALY gained, in 48.6% of the time the intervention would be cost-effective. Conclusion: Team-based care such as a physician-pharmacist collaboration appears to be a cost-effective strategy for treating hypertension. The intervention is most cost-effective for high-risk patients.