Effect of antihypertensive therapy on hospitalization and mortality among uncomplicated and high risk hypertensive patients

Objective: Evaluate the impact of antihypertensive drugs (AHD) on stroke and acute myocardial infarction (AMI) and death for 3 cohorts of patients: diabetics, high risk, and hypertensive. Methods: This was a retrospective cohort obervational study based on administrative database of 7 Italian Local Health Units. Newly treated patients with AHD were enrolled from 01/01/2004 to 06/30/2007. Drug utilization and incidence of death, stroke and AMI were measured until 12/31/2007. Results: The study enrolled 125,770 patients aged ≥ 18-year-old: 8516 diabetic, 8549 high risk, and 108,705 hypertensive. Diabetic and high risk patients were more frequently male (57.2%, 64.9% VS 46.6%) and older (66.4 ± 11.6, 67.5 ± 13.2 VS 61.6 ± 13.9) than hypertensive patients and were more treated with concomitant therapy. Drugs acting on the renin-angiotensin system were the more fre- quent choice in the three cohorts but with a dif- ferent prevalence (63.9%, 52.9%, 35.9% in dia- betic, hypertensive and high risk patients re- spectively). Adherent patients to AHD > 80% were 44.0% among diabetic patients, 48.4% among high risk, 35.2% among hypertensive. A Cox regression model showed that the risk of the combined outcome was determined by increasing age, male gender, presence of concomitant therapy, low adherence to AHD and first choice of AHD. Conclusions: An integrated analysis of prescription and hospital admission database has the great advantage that it uses routinely available data, it can be done quickly and by few staff, and it is less expensive than planned large scale survey.