Short-term adherence to β-blocker therapy among ethnic Chinese patients with hypertension: A cohort study

Background: Although poor control of hypertension is a problem worldwide, most published studies of adherence to antihypertensive medications have involved only white subjects.Objective: This study examined levels of and factors associated with short-term adherence to β-blocker therapy among a representative sample of ethnic Chinese patients with hypertension from a large territory in Hong Kong.Methods: Data for all hypertensive patients aged ≥18 years who received a prescription for a β-blocker at a visit to any public primary care clinic in the New Territory East cluster of Hong Kong and made at least 1 subsequent visit for a refill of this prescription between January 2004 and June 2007 were obtained from a validated clinical database generalizable to the Chinese population. The proportion of patients who were adherent to β-blocker therapy was measured based on the medication possession ratio (MPR), calculated over 2 consecutive visits. Good adherence was defined as an MPR ≥80%. Factors potentially associated with adherence to β-blockers were investigated using multivariable logistic regression analysis, with adjustment for age, sex, payment status, service type, district of residence, visit type, and number of comorbidities.Results: Data were obtained for 15,918 eligible patients (62.2% female; mean age, 59.1 years). Of these patients, 81.3% were adherent to β-blocker therapy. Factors associated with a greater likelihood of good adherence to β-blocker therapy were age ≥50 years (adjusted odds ratio [AOR], age 50–59 years = 1.53 [95% CI, 1.38–1.70]; AOR, age 60–69 years = 1.85 [95% CI, 1.64–2.10]; AOR, age ≥70 years = 1.88 [95% CI, 1.66–2.12]; all, P < 0.001); fee paid versus fee waived (AOR = 1.16 [95% CI, 1.06–1.28]; P = 0.001); attendance at a family medicine specialist clinic (AOR = 1.30 [95% CI, 1.09–1.54]; P = 0.003); and follow-up visit versus new-patient visit (AOR = 2.67 [95% CI, 2.42–2.95]; P < 0.001).Conclusion: Among these Chinese patients with hypertension, younger patients, those whose fees were waived, and those who were newly prescribed a β-blocker had a greater likelihood of being nonadherent.