M-18: Cost Utility Analysis of Fixed Versus Free Dose Antihypertensiv Combinations: Evidence From the 2014 MEPS
St. John's University United States
The main objective of this study is to evaluate the cost and the effectiveness of fixed dose antihypertensive combinations (FX) versus free dose antihypertensive combinations (FR) from United States payers’ perspective.
This cost-utility study used Medical Expenditure Panel Survey Household Component (MEPS- HC) data for analysis. For both groups of adults who used either FX or FR, the cost and the effectiveness are calculated as the mean of annual direct medication cost and utility scores from Short Form-6D.
A total of 2,117 patients are included in this study. Among them, 41.37% (n=876) patients, who used any fixed dose antihypertensive combinations which ingredients were also available in the market separately, are categorized in FX group. 56.62% and 55.20% of patients in FX and FR groups are females respectively. FX group contains 45.04% White, 29.25% Black, 17.16% Hispanic, and 6.04% Asian patients, compared to 44.63% White, 33.11% Black, 14.73% Hispanic, and 6.05% Asian patients in FR group. Patients in FR group are older than FX group (64.77 vs 61.50 p <.0001). The most popular pharmacology category of antihypertensive combinations in FX group is angiotensin converting enzyme inhibitor (ACE) plus thiazide combinations (42.24%), followed by angiotensin receptor blocker (ARB) plus thiazide (34.59%); whereas the most popular combination category in FR group is ACE plus calcium channel blocker (CCB) (27.24%), followed by ACE plus thiazide (26.59%).The mean annual cost for the FX group is approximately half of FR group ($449.5 vs. $1025.7, P < 0.0001). The most expensive pharmacology category in in FR group is ARB plus thiazide ($3,541) which is five times higher than the average cost in FX group ($667.42). The mean utility scores of patients in FX group is higher than FR group (0.7722 vs. 0.7666, P = 0.0179).
This cost-utility analysis suggests that fixed dose antihypertensive combination therapy is a dominant option, over free dose antihypertensive combination therapy. In other words, this study shows that combining antihypertensive drug ingredients into a single pill is associated with an increase in the utility scores and a decrease of the direct medication cost for payers in the United States.