Comparative Effectiveness of Antihypertensive Classes
Comparative Effectiveness of Antihypertensive Classes
Background: Few comparative effectiveness studies of treatment strategies using antihypertensive therapeutic classes in hypertension control have been assessed in a primary care environment. The objectives are to compare the effectiveness of common antihypertensive therapeutic classes initiated as monotherapy and of fixed-dose combinations (FDCs), free-equivalent combinations (FECs), and monotherapy on hypertension control.
Methods: This article reports observational comparative effectiveness analyses of data electronically extracted from electronic health records. The study population consisted of 8,676 patients with an incident prescription for an antihypertensive agent of a total of 79,176 patients receiving antihypertensive therapy in 33 geographically diverse primary care clinics. The main measures were reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) and rates of attaining goals per the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7).
Results: There were small, clinically insignificant differences in blood pressure reductions between the monotherapy classes. Higher rates of blood pressure control were obtained when patients were initiated on an angiotensin-converting enzyme inhibitor than a thiazide or thiazide-like diuretic (47.8% vs 39.9%) or a β-blocker versus a thiazide (45.9% vs 39.9%). Patients initiated on FDCs had significantly larger reductions in blood pressure than patients initiated on FECs (−17.3 vs −12.0 mm Hg SBP; −10.1 vs −6.0 mm Hg DBP) or monotherapy (−17.3 vs −13.6 mm Hg SBP; −10.1 vs −7.9 mm Hg DBP). Rates of attaining JNC7 goals also were better for FDCs than FECs (57.2% vs 42.5%) and for FDCs versus monotherapy (57.2% vs 44.9%).
Conclusions: Patients initiated on angiotensin-converting enzyme inhibitors and β-blockers had slightly higher rates of blood pressure control. The use of FDCs as initial therapy is more effective in the control of hypertension than monotherapy or FECs.
About one third of US adults (76.4 million) have hypertension, which is strongly associated with an increased risk of major adverse cardiovascular events (MACEs); treatment of hypertension has been shown to reduce that risk. However, only about half of hypertensive patients have control of their blood pressure, which leaves a substantial proportion of the population at an increased, but modifiable, risk of MACEs.
Monotherapy is the recommended initial approach for reducing blood pressure, except for stage II hypertension (blood pressure ≥160/100 mmHg). While some individuals can achieve control of their blood pressure and bring it to guideline-recommended levels using a single medication, 63% of 12,210 patients with a 5-year visit in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) required ≥2 agents. Another strategy for treating hypertension is the use of combination therapy: either a fixed-dose combination (FDC), which combines 2 active agents into a single pill, or a free-equivalent combination (FEC), which is the separate use of the corresponding single-agent pills. Several efficacy trials have previously shown combination therapy to be more effective than monotherapy in achieving blood pressure control, but we have found no randomized control trials that explicitly evaluated differences in efficacy between the 2 combination strategies. Other studies, however, have shown that patients using an FDC have greater adherence to and persistence with medication regimens compared with patients using an FEC.
The objectives of the present study were to (1) assess the comparative effectiveness of several antihypertensive therapeutic classes initiated as monotherapy, and (2) compare the effectiveness of the initial use of 3 treatment strategies (monotherapy, FDC, and FEC) in hypertensive patients receiving care in a diverse primary care setting.
Abstract and Introduction
Abstract
Background: Few comparative effectiveness studies of treatment strategies using antihypertensive therapeutic classes in hypertension control have been assessed in a primary care environment. The objectives are to compare the effectiveness of common antihypertensive therapeutic classes initiated as monotherapy and of fixed-dose combinations (FDCs), free-equivalent combinations (FECs), and monotherapy on hypertension control.
Methods: This article reports observational comparative effectiveness analyses of data electronically extracted from electronic health records. The study population consisted of 8,676 patients with an incident prescription for an antihypertensive agent of a total of 79,176 patients receiving antihypertensive therapy in 33 geographically diverse primary care clinics. The main measures were reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) and rates of attaining goals per the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7).
Results: There were small, clinically insignificant differences in blood pressure reductions between the monotherapy classes. Higher rates of blood pressure control were obtained when patients were initiated on an angiotensin-converting enzyme inhibitor than a thiazide or thiazide-like diuretic (47.8% vs 39.9%) or a β-blocker versus a thiazide (45.9% vs 39.9%). Patients initiated on FDCs had significantly larger reductions in blood pressure than patients initiated on FECs (−17.3 vs −12.0 mm Hg SBP; −10.1 vs −6.0 mm Hg DBP) or monotherapy (−17.3 vs −13.6 mm Hg SBP; −10.1 vs −7.9 mm Hg DBP). Rates of attaining JNC7 goals also were better for FDCs than FECs (57.2% vs 42.5%) and for FDCs versus monotherapy (57.2% vs 44.9%).
Conclusions: Patients initiated on angiotensin-converting enzyme inhibitors and β-blockers had slightly higher rates of blood pressure control. The use of FDCs as initial therapy is more effective in the control of hypertension than monotherapy or FECs.
Introduction
About one third of US adults (76.4 million) have hypertension, which is strongly associated with an increased risk of major adverse cardiovascular events (MACEs); treatment of hypertension has been shown to reduce that risk. However, only about half of hypertensive patients have control of their blood pressure, which leaves a substantial proportion of the population at an increased, but modifiable, risk of MACEs.
Monotherapy is the recommended initial approach for reducing blood pressure, except for stage II hypertension (blood pressure ≥160/100 mmHg). While some individuals can achieve control of their blood pressure and bring it to guideline-recommended levels using a single medication, 63% of 12,210 patients with a 5-year visit in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) required ≥2 agents. Another strategy for treating hypertension is the use of combination therapy: either a fixed-dose combination (FDC), which combines 2 active agents into a single pill, or a free-equivalent combination (FEC), which is the separate use of the corresponding single-agent pills. Several efficacy trials have previously shown combination therapy to be more effective than monotherapy in achieving blood pressure control, but we have found no randomized control trials that explicitly evaluated differences in efficacy between the 2 combination strategies. Other studies, however, have shown that patients using an FDC have greater adherence to and persistence with medication regimens compared with patients using an FEC.
The objectives of the present study were to (1) assess the comparative effectiveness of several antihypertensive therapeutic classes initiated as monotherapy, and (2) compare the effectiveness of the initial use of 3 treatment strategies (monotherapy, FDC, and FEC) in hypertensive patients receiving care in a diverse primary care setting.
