Changes in the pharmacologic treatment of hypertension in the department of veterans affairs 1997–1999: decreased use of calcium antagonists and increased use of β-blockers and thiazide diuretics

Abstract

Older studies of antihypertensive treatment have shown that prescribing patterns are not consistent with recommendations from expert national panels. We determined whether prescribing patterns for antihypertensive drugs changed recently in the largest integrated health care system in the United States. Specifically, we determine 1) patterns of antihypertensive medication use at all Department of Veterans Affairs (VA) medical facilities for fiscal years 1997 to 1999, 2) the cost of this care, and 3) savings associated with changes in treatment patterns. Data were aggregated by individual medication as well as by antihypertensive drug class. Estimates of VA national antihypertensive drug costs are based on the median cost and the number of units for each dosage form of each medication dispensed at all facilities. At VA medical facilities, calcium antagonist use went from 33% to 29.3% of antihypertensive treatment days between 1997 and 1999, angiotensin converting enzyme (ACE) inhibitor/angiotensin receptor blocker (ARB) use from 36.4% to 36.8%, β-blockers from 19.1% to 21.1%, and thiazide diuretic use from at 11.5% to 12.8%. If treatment patterns had remained the same between 1997 and 1999 in terms of the proportion of medications from each drug class, an additional six million dollars would have been spent on antihypertensive medications in 1999. Although calcium antagonists and ACE inhibitors/ARB remained the most commonly dispensed antihypertensives at VA facilities from 1997 to 1999, there was a proportional decrease in calcium antagonist use and an increase in the use of thiazide diuretics and β-blockers. These changes were consistent with improved compliance with VA national guidelines. The cost implications of these changes in practice patterns were considerable.