Cardiac medication prescribing and adherence after acute myocardial infarction in Chinese and South Asian Canadian patients

Abstract

BackgroundFailure to adhere to cardiac medications after acute myocardial infarction (AMI) is associated with increased mortality. Language barriers and preference for traditional medications may predispose certain ethnic groups at high risk for non-adherence. We compared prescribing and adherence to ACE-inhibitors (ACEI), beta-blockers (BB), and statins following AMI among elderly Chinese, South Asian, and Non-Asian patients.MethodsRetrospective-cohort study of elderly AMI survivors (1995-2002) using administrative data from British Columbia. AMI cases and ethnicity were identified using validated ICD-9/10 coding and surname algorithms, respectively. Medication adherence was assessed using the 'proportion of days covered' (PDC) metric with a PDC ≥ 0.80 indicating optimal adherence. The independent effect of ethnicity on adherence was assessed using multivariable modeling, adjusting for socio-demographic and clinical characteristics.ResultsThere were 9926 elderly AMI survivors (258 Chinese, 511 South Asian patients). More Chinese patients were prescribed BBs (79.7% vs. 73.1%, p = 0.04) and more South Asian patients were prescribed statins (73.5% vs. 65.2%, p = 0.001). Both Chinese (Odds Ratio [OR] 0.53; 95%CI, 0.39-0.73; p < 0.0001) and South Asian (OR 0.78; 95%CI, 0.61-0.99; p = 0.04) patients were less adherent to ACEI compared to Non-Asian patients. South Asian patients were more adherent to BBs (OR 1.3; 95%CI, 1.04-1.62; p = 0.02). There was no difference in prescribing of ACEI, nor adherence to statins among the ethnicities.ConclusionDespite a higher likelihood of being prescribed evidence-based therapies following AMI, Chinese and South Asian patients were less likely to adhere to ACEI compared to their Non-Asian counterparts.

Cardiovascular Disease in South Asian Migrants

“…In a retrospectivecohort study based in British Columbia, Canada, SA were less likely to adhere to angiotensin converting enzyme inhibitor medications compared to Europids (OR 0.78, 95% CI 0.61-0.99), although they were more likely to adhere to beta-blockers. 126 In a UK population-based cohort-study, SA were significantly less likely to adhere to evidence- 127 Likewise, in British Columbia, Canada, SA migrants were less likely to adhere to antihypertensive medication prescription compared to Europids (OR 0.38; 95% CI 0.36-0.40). 128 Possible explanations include patient knowledge of disease and medications, family support, forgetfulness, and therapy associated side-effects.…”

Outcomes After Acute Myocardial Infarction in South Asian, Chinese, and White Patients

“…28,39 Nevertheless, the higher rate of cardiac catheterization may signal that cardiologists are aware of the higher prevalence of coronary disease in this group and may provide more aggressive care. 40 In a study of elderly AMI survivors in British Columbia, South Asian and Chinese patients were as likely or more likely to be prescribed secondary prevention therapy as their white counterparts. 40 Other differences in long-term cardiac disease management such as changes in health behaviors after AMI, 41 secondary risk factor reduction, 39 greater adherence to evidence-based therapies, and differences in family supports may contribute to the lower mortality observed among South Asian patients.…”

“…40 In a study of elderly AMI survivors in British Columbia, South Asian and Chinese patients were as likely or more likely to be prescribed secondary prevention therapy as their white counterparts. 40 Other differences in long-term cardiac disease management such as changes in health behaviors after AMI, 41 secondary risk factor reduction, 39 greater adherence to evidence-based therapies, and differences in family supports may contribute to the lower mortality observed among South Asian patients. The lower total mortality found among South Asian AMI patients may also partly reflect their lower risk of noncardiac causes of death, including cancer.…”

Adherence to evidence-based secondary prevention pharmacotherapy in patients after an acute coronary syndrome: A systematic review

“…Overall, 6 studies 23,26,29,31,36,37 examined the use of a single cardiac medication, while the other 10 studies 24,25,27,28,30,32e35,38 examined adherence to multiple cardiac drugs. The most common measures used for assessing medication adherence were proportion of days covered (PDC) (n ¼ 9), 24,26,27,29,30,33,35,37,38 followed by medication possession ratio (MPR) (n ¼ 5), 23,25,31,32,34 electronic medication monitors (n ¼ 1), 36 and self-reported data (n ¼ 1). 28 Twelve studies 23,26,27,29e33,35e38 defined good adherence to prescribed medication using a percentage cut-off at 80%, while two studies 24,25 used a cut-off at 75%.…”