Factors associated with antihypertensive drug discontinuation among Chinese patients: a cohort study.
BACKGROUND
Antihypertensive drug discontinuation imposes a substantial health services burden but few studies have addressed the factors associated with their discontinuation in Chinese patients. This study evaluated the association between age, gender, and drug classes with antihypertensive discontinuation.


METHODS
From clinical databases, we included all adult patients prescribed an antihypertensive medication during January 2004 to June 2007 in one large territory of Hong Kong. We studied the factors associated with drug discontinuation within 180 days after the first prescription date by multivariable regression analysis.


RESULTS
From 93,286 eligible patients, 13.2% discontinued their antihypertensive prescriptions. Younger (<50 years; adjusted odds ratio (aOR) = 0.63 for patients aged 50-59 years; 0.52 for patients aged 60-69 years; 0.70 for those aged >or=70 years; all P < 0.001) and male patients (aOR = 1.05, P = 0.027) were more likely to have drug discontinuation. When compared with thiazide diuretics, patients prescribed beta-blockers were more likely (aOR = 1.67, P < 0.001) and patients prescribed calcium channel blocker (CCB) (aOR = 0.76, P < 0.001) and combination therapy (aOR = 0.73, P < 0.001) were less likely to have drug discontinuation. Stratified analyses in different age and gender groups reported similar results; except that only elderly male patients (aOR = 1.12, P = 0.002) and younger patients (aOR = 2.43 for patients aged <50 years, P < 0.001) prescribed beta-blocker were more likely to have drug discontinuation.


CONCLUSIONS
Discontinuation of antihypertensive drug treatment in ethnic Chinese is more likely to occur in younger, male patients, or those prescribed beta-blockers. These data suggest that more meticulous monitoring of patient adherence is required in patients with these characteristics.
School of Public Health and Department of Community and Family Medicine, Faculty of Medicine, Chinese University of Hong Kong, Shatin, Hong Kong.
Martin C S
MC
Wong
Johnny Y
JY
Jiang
Trevor
T
Gibbs
Sian M
SM
Griffiths
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D044466:Asian People; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D055118:Medication Adherence / Q000208:ethnology*; D008875:Middle Aged; D012044:Regression Analysis; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D049993:Sodium Chloride Symporter Inhibitors