Association between antihypertensive agent use and hospital admissions in a managed care population

Utilization of medical care services has been used as a surrogate for outcome of patient compliance with treatment regimens. Antihypertensive treatment status and selection of drug agents may influence medical utilization. The purpose of this study was to determine the association between medically untreated hypertension and treated hypertension according to class of antihypertensive agent with the rate of hospitalization.

This is a retrospective, observational study on adult hypertensive patients based on claim data from a network-model HMO. The 12,548 patients were identified by ICD-9-CM hypertensive codes over a 3-year period. The hospital admission rate was the outcome measurement. The exploratory variables included antihypertensive treatment status and drug class. Patients' age, gender, and coexisting medical conditions were treated as confounding factors. Descriptive analyses and multivariate regression analyses were performed.

Coexisting medical conditions were significant factors in hospital admission rates. Compared with diuretic treatment, there were no differences in hospital admission rates among hypertensive patients treated with an angiotensin II antagonist or angiotensin-converting enzyme inhibitor. Untreated patients or those treated with beta-blockers or calcium channel blockers experienced higher hospitalization rates (95% CI, 1.25-1.90, 1.03-1.44, and 1.08-1.46, respectively).

Compared with the major antihypertensive agents or no therapy for hypertension, diuretic or angiotensin-converting enzyme inhibitor therapy may result in a reduced rate of hospital utilization.