Short-term adherence to beta-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 beta-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 > or = 18 years who received a prescription for a beta-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 beta-blocker therapy was measured based on the medication possession ratio (MPR), calculated over 2 consecutive visits. Good adherence was defined as an MPR > or = 80%. Factors potentially associated with adherence to beta-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 beta-blocker therapy. Factors associated with a greater likelihood of good adherence to beta-blocker therapy were age > or = 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 > or = 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).


CONCLUSIONS
Among these Chinese patients with hypertension, younger patients, those whose fees were waived, and those who were newly prescribed a beta-blocker had a greater likelihood of being nonadherent.
Wong
Martin C S
MC
School of Public Health and Primary Care, Faculty of Medicine, Chinese University of Hong Kong, Shatin, NT, Hong Kong.
Jiang
Johnny Y
JY
Griffiths
Sian M
SM
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000367:Age Factors; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D016208:Databases, Factual; D018450:Disease Progression; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012737:Sex Factors; D012959:Socioeconomic Factors; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents