COST-MINIMIZATION ANALYSIS OF INITIAL ANTIHYPERTENSIVE THERAPY IN PATIENTS WITH MILD-TO-MODERATE ESSENTIAL DIASTOLIC HYPERTENSION

In addition to efficacy and safety, the cost of therapy has become an increasingly important factor to consider when selecting drugs to trea t patients with mild-to-moderate hypertension. However, acquisition pr ices alone do not determine the total cost of therapy. To better asses s total costs, we conducted a systematic, retrospective, cost-minimiza tion analysis of drugs used to treat 673 patients with newly diagnosed , mild-to-moderate (>95 to <110 mmHg) diastolic hypertension between t he years 1985 and 1992. Patients included in the study had started ant ihypertensive monotherapy, and a minimum of one dose titration was req uired before adding another antihypertensive agent to the regimen. A p atient had to have a diastolic blood pressure of less-than-or-equal-to 90 mmHg while undergoing therapy to be included in the analysis. Drug classes included diuretics, beta-adrenergic blockers, centrally actin g alpha-2-agonists, alpha1-adrenergic blockers, calcium channel blocke rs, and angiotensin-converting enzyme (ACE) inhibitors. Costs, adjuste d to 1992 price levels, were analyzed for 32 individual agents for eac h of the following five cost variables: initial drug acquisition, supp lemental drug acquisition, laboratory monitoring, clinic visits, and t reatment of side effects. Mean total costs per patient for all five va riables by drug class were $895 for beta-blockers, $1043 for diuretics , $1165 for centrally acting alpha2-agonists, $1243 for ACE inhibitors , $1288 for alpha1-blockers, and $1425 for calcium channel blockers. H owever, costs within each class varied considerably. Acquisition cost was often a poor predictor of the total cost of treatment. Therefore, acquisition cost must be considered in conjunction with a number of ou tcome variables to assess the true cost of antihypertensive therapy.