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.