Costs and Outcomes Comparison of Treatments for Hypertension

Cincinnati—Hypertension affects 1 in every 3 adults in the United States and prolonged hypertension can lead to severe complications, including stroke, congestive heart failure, renal failure, myocardial infarction, and other conditions that can reduce quality of life and increase the risk of mortality. The economic burden of hypertension is substantial: the 2010 estimated direct cost was $54.9 billion for hypertension and $324.1 billion for cardiovascular disease.

Recommended first-line therapy for patients with uncomplicated hypertension is treatment with hydrochlorothiazide (HCTZ) or chlorthalidone (CLD), thiazide or thiazide-like diuretics. Previously, HCTZ and CLD have been considered interchangeable; however, recent studies have found that CLD has a longer duration of action and is 1.5 to 2 times as potent as HCTZ.

More effective control of uncomplicated hypertension has been achieved with a combination of angiotensin receptor blockers (ARBs) and diuretics. Researchers recently conducted a study to compare clinical and economic outcomes between patients with uncomplicated hypertension treated with combination therapies of ARB/CLD versus ARB/HCTZ. They reported study results during a poster session at the AMCP meeting. The poster was titled Comparisons of Costs and Clinical Outcomes in Hypertensive Patients Treated with Angiotensin Receptor Blockers plus Chlorthalidone or Hydrochlorothiazide.

The study utilized data from the Integrated-Health-Care-Information-Services National Managed Care Benchmark Database from January 1, 1999, through March 31, 2007. The database, which includes both medical and drug claims, includes 30 health plans and covers 25 million lives.

Patients were selected if they had ≥2 prescriptions of an ARB/CLD or ARB/HCTZ (with treatment components within 30 days of each other), and were continuously enrolled for at least 6 months prior to (baseline period) and 12 months following their first fill of either ARB/CLD or ARB/HCTZ (index date). If the treatment components were filled on separate dates, the latter fill date was the index date. Patients with an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis of essential hypertension at baseline and no diagnosis for severe hypertension with complications at any time prior to the index date were included, as were those with no prescription of a fixed-dose combination of ARB/HCTZ on the index date (to ensure that both cohorts were comparable, because no fixed-dose combination of ARB/CLD was marketed).

Patients in ARB/CLD and ARB/HCTZ cohorts were matched in a 1:5 ratio.

The clinical outcomes of the study were rates of urgent care utilization, hospitalizations, and emergency department visits (measured from index date to end of enrollment). Economic outcomes were measured during the 1-year postindex period and included both all-cause and hypertension-related healthcare costs. Total healthcare costs included medical and pharmacy costs. Hypertension-related costs included those associated with diagnosis for congestive heart failure, cardiovascular disease, myocardial infarction, peripheral vascular disease, and stroke.

Baseline characteristics were similar between the matched patients with ARB/CLD (n=836) and patients with ARB/HCTZ (n=4180) with the exception of outpatient cost and drug cost, which were slightly different between the 2 cohorts.

The rates of urgent care visits were significantly lower in the ARB/CLD cohort compared with the ARB/HCTZ cohort (19.6% vs 23.5%, respectively, at one year, and 34.2% vs 38.0%, respectively, at 2 years; P=.002). Rates of hospitalization were also lower in the ARB/CLD cohort compared with the ARB/HCTZ cohort, but the difference did not reach statistical significance.

During the 1-year postindex period, patients in the ARB/CLD cohort incurred significantly lower medical and total healthcare costs compared with the ARB/HCTZ cohort ($5374 vs $5507, total medical costs, respectively; $7927 vs $8963, total healthcare costs, respectively; P<.05 for the comparison).

Costs for prescription drugs did not differ significantly between the 2 cohorts. Hypertension-related total healthcare costs also did not differ significantly between the groups.

In summary, the researchers said, “Patients diagnosed with uncomplicated hypertension initiated on ARB/CLD combinations were less likely to incur urgent care services and incurred lower healthcare costs compared with patients treated with ARB/HCTZ. The cost saving was partly driven by outpatient medical costs.”

This study was supported by Takeda Pharmaceutical Company Limited.