Trends in the Treatment of Hypertension within Managed Care Organizations: A National Survey of HMO Pharmacy Directors

Abstract

OBJECTIVE: To estimate the prevalence of changes to the initial treatment regimen of hypertensive patients in a managed care setting and to identify the factors having the most impact on the cost of treatment. Utilization patterns specifically related to angiotensin converting enzyme inhibitors (ACEls) and calcium channel blockers (CCBs) were looked at because of their particular cost impact. Secondary goals were to assess the types of changes made to therapy and to estimate the ACEI/CCB concomitancy rates (the number of patients receiving both medications at the same time) among these hypertensive patients, and the cost impact of these. DESIGN: In May 1995, a survey regarding the treatment of hypertension in managed care was faxed to a random sampling of pharmacy directors of 250 large (greater than 40,000 enrollees) managed care plans throughout the United States. A total of 29 pharmacy directors completed and returned the survey; all responses were included in the study analysis. The 29 plans represented various types of HMO-staff, group, independent-practice-association, network, and mixed-model HMOs-which collectively accounted for 8.9 million enrollees, or approximately 16% of the total HMO universe. All plans had similar age and gender demographics composition. SETTING: Not applicable. PATIENT/ PARTICIPANTS: 29 Pharmacy directors. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: PMPY and subjective evaluations. RESULTS: Most of the responding pharmacy directors (81%) indicated that the average hypertensive patient undergoes at least one, and often more than one, modification to the therapy regimen before achieving maintenance therapy levels (i.e., control of high blood pressure). When using either an ACEI or a CCB, the most common change made to initial therapy was to increase the medication dosage. This was estimated to occur 26.8% of the time with ACEls and 22.5% with CCB therapy. Among patients who started therapy on ACEls, switching to an antihypertensive in another class was the next most common step (18%), followed by adding a CCB or switching to another ACEI, both of which occurred about 11% of the time. Among patients who started therapy on CCSs, the next most common change after increasing the dosage was to add a diuretic (15%), followed by switching to another CCB (13%) or adding an ACEI (5%). CONCLUSION: Based on the qualitative responses of the pharmacy directors, it appears that changes to the initial antihypertensive treatment regimen are common. The survey data support the American Heart Association's assumption that even among those taking antihypertensive medication, blood pressure remains uncontrolled (a systolic level 2:140 and/or a diastolic level 2:90) in an estimated 27% of patients. In addition, the need for modifications to therapy appears to have important cost implications. Overall, these findings suggest that more aggressive management of hypertension may effectively reduce both the number of subsequent physician visits and the need for complicated therapeutic regimens, which could improve patient compliance.