Pharmacoepidemiological profiles of prescriptions for antihypertensive agents among ethnic Chinese patients

Abstract

We compared the short- and long-term cumulative incidences of add-on therapy across the major anti-hypertensive drug classes among Chinese patients who had newly received an antihypertensive agent. We analyzed 16,154 adult patients with uncomplicated hypertension who had newly received an antihypertensive monotherapy in one large territory of Hong Kong during January 2004 to June 2007. We compared the cumulative incidences of and factors associated with add-on therapy by drug classes at 180 days and 360 days using binary logistic regression analyses. The crude cumulative incidences of add-on therapy at 180 days were not statistically significantly different among those receiving thiazide diuretics (6.26%), b-blockers (5.99%), calcium channel blockers (CCB) (5.95%) or drugs acting on the renin angiotensin system (RAS) (4.41%), and these figures were similar at 360 days (both p = 0.213). The odds ratios of add-on therapy for RAS (0.72, 95% CI 0.49 - 1.06), thiazide diuretics (1.08, 95% CI 0.85 - 1.37) and beta-blockers (1.02, 95% CI 0.86 - 1.22) were not statistically significant compared to CCB at 180 days and 360 days. Male patients and younger subjects were more likely to receive an add-on therapy in both time frames. This study suggested that the major antihypertensive drug classes had similar add-on rates in real-life clinical practice.