Physician underutilization of effective medications for resistant hypertension at office visits in the United States: NAMCS 2006-2010.

Abstract

BACKGROUND: The American Heart Association (AHA) published guidelines for treatment of resistant hypertension in 2008 recommending use of thiazide diuretics (particularly chlorthalidone), aldosterone antagonists, and fixed-dose combination medications, but it is unclear the extent to which these guidelines are being followed. OBJECTIVE: To describe trends in physician use of recommended medications for resistant hypertension and assess variations in medication use based on geography, physician specialty and patient characteristics. DESIGN: Cross-sectional analysis using the National Ambulatory Medical Care Survey from 2006 to 2010. STUDY SAMPLE: We analyzed visits of hypertension patients to family physicians, general internists, and cardiologists. Resistant hypertension was defined as concurrent use of ≥ 4 classes of blood pressure (BP) medications or elevated BP despite the use of ≥ 3 medications. Pregnant patients and visits with diagnosed heart failure or end-stage renal disease were excluded. MAIN OUTCOME: Use of AHA-recommended medications for management of resistant hypertension. RESULTS: Of 19,500 patient visits with hypertension, 1,567 or 7.1 % CI (6.6-7.7 %) met criteria for resistant hypertension. Thiazide diuretic use was reported in 58.9 % of visits pre-guidelines vs. 54.8 % post-guidelines (p = 0.37). Use of aldosterone antagonists was low and also did not change significantly after guideline publication (3.1 % vs. 4.5 %, p = 0.27). Fixed-dose combinations use was 42.0 % before and 37 % after guideline publication (p = 0.29). Each 10-year increase in patient age was associated with lower thiazide use (OR 0.87, CI 0.77-0.97), as was presence of comorbid ischemic heart disease (OR 0.62, CI 0.41-0.94). Medication use did not vary by geography or physician specialty. CONCLUSION: Use of AHA-recommended medications for resistant hypertension remains low after publication of guidelines. Healthcare systems should encourage more frequent prescribing of these medications to improve care in this high-risk population.