Cardiac medication prescribing and adherence after acute myocardial infarction in Chinese and South Asian Canadian patients
© Lai et al; licensee BioMed Central Ltd. 2011
Received: 28 January 2011
Accepted: 18 September 2011
Published: 18 September 2011
Failure 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.
Retrospective-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.
There 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.
Despite 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.
Keywordsmedication adherence acute myocardial infarction ethnicity
Acute myocardial infarction (AMI) is one of the leading causes of death across multiple ethnic groups in North America. Landmark clinical trials established the efficacy of medications in reducing morbidity and mortality associated with AMI [1–3]. The morbidity and mortality benefits observed in these trials were largely among patients who were highly adherent. However, in real-world settings, typical adherence rates for prescribed medications are 50%, and are even lower in developing countries [4, 5]. Medication non-adherence is associated with substantial worsening of disease, increased health care costs, and death [6–9]. From re-hospitalizations to lost workdays, the collective economic burden of non-adherence is estimated to be over $100 billion per year.
Non-adherence is a multidimensional phenomenon, affected by socio-economic status, health systems, disease states, pharmacological therapies, and patient beliefs . Whether patient ethnicity plays a role in medication adherence is unclear [5, 10]. To date, the literature yields variable results [11–14] with little data on medication adherence in Chinese and South Asian populations, the largest, and fastest growing, ethnic groups in North America. Language barriers, mistrust of Western medicine, and preference for traditional therapies could adversely impact medication adherence in these groups. Furthermore, different ethnicities may react differently to the medications. For example, Asian patients have been noted to have a greater risk for adverse effects from ACEI . Therefore, we compared prescribing and adherence to evidence-based therapies [ACE inhibitors (ACEI), beta-blockers (BB), and HMG-CoA reductase inhibitors (statin)] using a large multi-ethnic cohort of elderly Chinese, South Asian, and Non-Asian survivors of AMI.
Our research conformed to the Helsinki Declaration and to local legislation. Ethics approval was obtained from The University of British Columbia Providence Health Care Research Ethics Board.
Medication prescription (for any of ACEI, BB, or statin) was determined by linkage to the BC Pharmacare prescription database. These medication classes were selected because of their proven mortality benefit in secondary prevention of cardiovascular events [1–3, 16–19]. The Pharmacare database contains records of all outpatient prescriptions filled in BC by residents aged 65 years or older including date of prescription fill and days of medication supplied. Previous studies demonstrate excellent accuracy with prescription claims databases [0.7% error rate] . By restricting our analysis to patients aged 66 years and older, we minimize the effects of patient costs on adherence as these individuals pay a deductible on medications up to Cdn$200/year, which was increased to Cdn$275/year on January 1st, 2002. All medication costs above this deductible are paid by Pharmacare.
The cohort consisted of patients aged 66 years or older who were discharged from hospital with a most responsible diagnosis of AMI. To identify index AMI cases, we used the International Classification of Diseases (ICD9/ICD10) coding algorithms for hospital administrative data [ICD9 410.x; ICD10: I21.x]. These coding algorithms for AMI have been extensively validated against multi-centre chart audits [21–23]. We only included patients who survived at least 1 year and 3 months after the hospital admission, to allow for a sufficient time period to calculate medication adherence and excluded non-BC residents.
Identification of ethnicity
Ethnicity is the common and/or inherited traits shared by people of the same race, ancestry, background and/or culture [24, 25]. As self-reported ethnicity is not available in administrative databases, we used surname algorithms to categorize patient ethnicity as Chinese (from China, Taiwan or Hong Kong) or South Asian (from Pakistan, India or Bangladesh). The remaining patients will be referred to as 'Non-Asian' although 7% of this non-Chinese, non-South Asian group is a visible minority according to the Canadian Census . To identify patients of Chinese descent, we used Quan's surname algorithm that has a sensitivity of 78%, a specificity of 99.7% and a positive predictive value of 81% compared to self-reported ethnicity using the Canadian Community Health Survey . The Nam Pehchan surname algorithm has a 90-94% sensitivity, a 99.4% specificity and a positive predictive value of 63-96% for determining South Asian ethnicity [28, 29].
Since the Pharmacare database only includes data on prescription medications, we limited our selections to ACEIs, BBs, statins, calcium-channel blockers (CCB), and diuretics. Calcium-channel blockers and diuretics were included to contrast the prescribing of cardiac medications with proven and non-proven mortality benefit. Angiotensin II receptor blockers (ARBs) were not included in our analysis as these agents were not part of post-AMI guidelines during the study period. We collected data on prescribing, within the 3 months prior to AMI and at 1 year after AMI. Since prescribing patterns change over time, we restricted our collection period to April 1st, 1999 to March 31st, 2003 to better reflect more recent prescribing practices.
Assessment of adherence
We used the 'proportion of days covered' (PDC), a commonly used metric for evaluating medication adherence. The PDC represents the number of days a patient had a medication available, divided by the days observed [6, 30]. Patients had to obtain a supply of medication within 3 months of hospital discharge. We used prescription data from April 1st, 1994 to March 31st, 2003 to ensure we had an adequate sample size. To better reflect long-term medication adherence, we used an observation period of 1 year after the first-filled prescription . A previous study of AMI patients demonstrated longer assessments of adherence were not significantly different from a one-year measurement . We calculated the PDC for a single class of medication, as well as the PDC for any one of ACEI, BB, or statin prescriptions, since our interest was in adherence to any or all proven therapies. We defined adherence as a PDC of ≥ 80%, and suboptimal adherence as a PDC < 80%. The 80% cut-point is similar to that used in other medication adherence studies and is associated with mortality benefit after AMI compared to other levels of adherence [6, 30].
Patient characteristics according to ethnicity
N = 258
N = 511
N = 9157
Age, n (%)
≥ 80 years
Female, n (%)
Income, n (%) *
$43,148 - 54,103
$54,104 - 68,206
$68,207 - 221,991
> 50km to hospital, n (%)
Number of hospitalizations, mean (SD)
Total # of medications†, mean (SD)
Prior use of ACEI, BB, or statin‡, n (%)
Comorbidities, n (%)
Baseline characteristics were compared between ethnic groups using chi-square testing for categorical variables and ANOVA for continuous variables. Missing values, found in measures of socio-economic status quintile (< 4.8%), were excluded from the analysis (see Table 1). Multivariable logistic regression models, adjusting for age, sex, residential distance from hospital, income quintile, admission year, number of baseline medications, number of re-admissions to hospital, prior use of same medication, and comorbid conditions from the Ontario AMI prediction rule, were constructed to examine the independent relationship between adherence (PDC ≥ 80%) and ethnicity. Logistic regression model assumptions were satisfied. Statistical significance was defined as a 2-tailed p < 0.05. All analyses were performed using SAS statistical software version 9.1 (SAS Institute Inc, Cary, NC).
Of 9926 patients who met inclusion criteria, 258 (2.6%) were Chinese, 511 (5.1%) were South Asian, and 9157 (92.3%) were categorized as Non-Asian. Table 1 illustrates baseline socio-demographic and clinical characteristics between the three ethnic groups. Chinese and South Asian patients tended to reside in urban areas and comprised a larger proportion of the lower income quintiles than Non-Asian patients. There were more Chinese and South Asian patients with diabetes, congestive heart failure, kidney disease, hypertension, and more Chinese patients with cerebrovascular disease. Both Chinese and South Asian patients were prescribed a greater number of total medications within 3 months of hospital discharge.
Prescribing of evidence-based therapies
Medication prescribing according to ethnicity 3 months prior to AMI and 1 year post AMI, n (%)
3 months prior to AMI
1 year post AMI
(n = 150)
(n = 224)
(n = 3697)
(n = 197)
(n = 370)
(n = 6115)
ACEI, BB, or Statin
Adherence to evidence-based therapies
Adherence to cardiac medications (PDC ≥ 80%) according to ethnicity and medication
Adj. OR (95%CI)*
Adj. OR (95%CI)*
Chinese vs. Non-Asian
South Asian vs. Non-Asian
ACEI, BB, or statin, %
In the adjusted analysis, Chinese patients were less likely to adhere to ACEI, compared to Non-Asians, [OR 0.53; 95%CI: 0.39-0.73]. Chinese patients, overall, were also less likely to be adherent to any of ACEI, BB, or statin medication [OR 0.70; 95%CI: 0.51-0.95]. Compared to Non-Asians, South Asians were less likely to be adherent to ACEI [OR 0.78; 95%CI: 0.61-0.99] but more likely to be adherent to BBs [OR 1.3; 95%CI: 1.04-1.62]. Among the medications with less evidence for cardio-protection, there was no significant difference in adherence to CCBs, but South Asian patients were less likely to adhere to diuretics compared to Non-Asian patients.
In this study, elderly Chinese and South Asian patients were as or more likely to be prescribed evidence-based therapies following AMI compared to their Non-Asian counterparts. However, adherence varied by medication class in the ethnic groups.
Overall prescribing rates for secondary prevention of AMI were poor for statin medications (68%) but higher for ACEI and BB medications (77-78%). Overall prescribing of these medications was similar to those in other studies [6, 35]. Appropriately, we saw a decrease in prescribing for CCBs. We found that Chinese and South Asian patients were more likely to be prescribed BBs and statins compared to Non-Asian patients. Reasons for this are unclear; prescribing physicians may consider Chinese and South Asian patients to be at higher cardiac risk, necessitating more aggressive management. Studies demonstrate that South Asian patients, for example, are more or just as likely to receive invasive cardiovascular procedures following AMI, compared to their Non-Asian counterparts . Alternatively, Chinese and South Asian patients may have been more likely to fill their prescriptions once discharged from hospital compared to Non-Asian patients. Non-Asian patients tended to reside outside of urban areas where access to medical follow-up was perhaps more limited, potentially resulting in fewer opportunities to fill prescriptions.
This study found that elderly Chinese patients were less likely to adhere to any evidence based therapy following AMI relative to Non-Asian patients. To our knowledge, this is the first study evaluating the adherence to secondary prevention medications following AMI in Chinese and South Asian patients. In addition to the factors associated with non-adherence found in the general population, non-adherence in these ethnic populations may be further amplified by language barriers [37–40] and differences in health literacy [40–42] among ethnocultural groups. Furthermore, ethnocultural patients may have a preference for alternative or natural therapies [43–45], and some may perceive that antihypertensive therapy is not beneficial . Furthermore, differences in health beliefs and strong Eastern views of care (e.g. viewing disease as a result of fate and avoidance of medical visits) are associated with poor adherence to treatment recommendations . Intriguingly, even within the same class of medication, we found that adherence varied by patient ethnicity with the greatest proportion of suboptimal adherence for ACEI in both Chinese and South Asian patients. This observation raises suspicion that the differences in adherence may be, at least in part, attributed to greater adverse effect profiles within these ethnic groups. In a systematic review of cardiovascular drug utilization, ACEI-induced cough was more prevalent in Asian patients than in the general population, although South Asian patients were not studied separately . Adherence to statins was similar across ethnic groups despite the fact that, in post-marketing surveillance, rosuvastatin was associated with greater statin-induced myopathy in Asian patients .
This study had several limitations. First, we only used a proxy measurement for adherence using prescriptions claims data. Although this approach does not ensure that the medications were ingested, prescription claims data highly correlates with home inventory pill counts, as well as serum measures of drug presence [49–51]. As with all observational studies, we were limited by residual confounders since we were unable to assess other factors associated with non-adherence such as dementia and depression. Similarly, we did not have access to other clinical information such as left ventricular function or creatinine, but we attempted to adjust for some of the clinical variables by including the diagnosis of CHF or kidney disease, for example, in Table 1. We did not include Angiotensin receptor blockers (ARBs) in our analysis. These agents have become more widely used since the study period, and are often prescribed for patients who experience negative side effects from ACEI, thereby potentially impacting adherence to any renin-angiotensin-aldosterone agent (either ACEI or ARBs). Finally, we investigated medication adherence among major ethnic groups in Canada who were elderly; these results may not be generalized to other ethnic groups or to younger patients within these groups.
Compared to their Non-Asian counterparts, South Asian and Chinese elderly patients are just as likely or more likely to receive proven secondary prevention therapies. However, in this cohort of high cardiac risk patients, 25% of patients did not fill a prescription for these therapies, suggesting greater need to improve prescribing in all ethnic groups following AMI. Chinese patients were less likely to be adherent to any secondary prevention medication and specifically, ACEI therapy. South Asian patients were also less likely to be adherent to ACEI therapy relative to their Non-Asian counterparts. This study identifies an at-risk group of patients that require aggressive monitoring, follow-up and support to optimize adherence. Future studies evaluating underlying cultural barriers to adherence are needed to develop culturally-tailored interventions to improve adherence. The disproportionately lower adherence to ACEI in South Asian and Chinese patients, raises suspicion that both of these groups may suffer greater adverse effects associated with ACEI.
The Canadian Institutes of Health Research provided funding for the study. Salary support for the co-authors was provided by the Canadian Institutes of Health Research (HQ, AP, NAK), Michael Smith Foundation for Health Research (AP), and Alberta Heritage Foundation for Medical Research (HQ, KMK). NAK and MG had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
- First International Study of Infarct Survival collaborative group: Randomized trial of intravenous atenolol among 16,027 cases of suspected acute myocardial infarction: ISIS-1. Lancet. 1986, 2: 57-66.Google Scholar
- Heart Outcomes Prevention Evaluation Study Investigators: Effects of an angiotensin-converting-enzyme inhibitor, ramipril, on cardiovascular events in high-risk patients. N Engl J Med. 2000, 342: 145-53.View ArticleGoogle Scholar
- Heart Protection Study Collaborative Group: MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20 536 high-risk individuals: a randomized placebo-controlled trial. Lancet. 2002, 360: 7-22.View ArticleGoogle Scholar
- Sackett DL, Snow JC: The magnitude of adherence and nonadherence. Compliance in Health Care. Edited by: Haynes RB, Taylor DW, Sackett DL. 1979, Baltimore: Johns Hopkins University Press, 11-22.Google Scholar
- Sabate E: Adherence to long-term therapies: evidence for action. 2003, Geneva: World Health OrganizationGoogle Scholar
- Rasmussen JN, Chong A, Alter DA: Relationship between adherence to evidence-based pharmacotherapy and long-term mortality after acute myocardial infarction. JAMA. 2007, 297: 177-86. 10.1001/jama.297.2.177.View ArticlePubMedGoogle Scholar
- Berg JS, Dischler J, Wagner DJ, Raia JJ, Palmer-Shevlin N: Medication compliance: a healthcare problem. Ann Pharmacother. 1993, 27 (suppl 9): S1-24.PubMedGoogle Scholar
- Rodgers PT, Ruffin DM: Medication nonadherence - Part I: The health and humanistic consequences. Manag Care Interface. 1998, 11: 58-60.PubMedGoogle Scholar
- Rodgers PT, Ruffin DM: Medication nonadherence - Part II: a pilot study in patients with congestive heart failure. Manag Care Interface. 1998, 11: 67-9. 75PubMedGoogle Scholar
- Osterberg L, Blaschke T: Adherence to medication. N Engl J Med. 2005, 353: 487-97. 10.1056/NEJMra050100.View ArticlePubMedGoogle Scholar
- Francis CK: Hypertension, cardiac disease, and compliance in minority patients. Am J Med. 1991, 91: 1A.29S-36S.View ArticleGoogle Scholar
- Charles H, Good C, Hanusa BH, Chang CH, Whittle J: Racial differences in adherence to cardiac medications. J Natl Med Assoc. 2003, 95: 17-22.PubMedPubMed CentralGoogle Scholar
- Bosworth HB, Dudley T, Olsen MK, Voils CI, Powers B, Goldstein MK, Oddone EZ: Racial differences in blood pressure control: potential explanatory factors. Am J Med. 2006, 119: 70.e9-15. 10.1016/j.amjmed.2005.08.019.View ArticleGoogle Scholar
- Siegel D, Lopez J, Meier J: Antihypertensive medication adherence in the Department of Veterans Affairs. Am J Med. 2007, 120: 26-32. 10.1016/j.amjmed.2006.06.028.View ArticlePubMedGoogle Scholar
- McDowell SE, Coleman JJ, Ferner RE: Systematic review and meta-analysis of ethnic differences in risks of adverse reactions to drugs used in cardiovascular medicine. BMJ. 2006, 332: 1177-81. 10.1136/bmj.38803.528113.55.View ArticlePubMedPubMed CentralGoogle Scholar
- Freemantle N, Cleland J, Young P, Mason J, Harrison J: β blockade after myocardial infarction: systematic review and meta regression analysis. BMJ. 1999, 318: 1730-7.View ArticlePubMedPubMed CentralGoogle Scholar
- The Scandinavian Simvastatin Survival Study group: Randomized trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian simvastatin survival study (4S). Lancet. 1994, 344: 1383-9.Google Scholar
- Ryan TJ, Antman EL, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Reigel BJ, Russell RO, Smith III EE, Weaver WD: 1999 update: ACC/AHA guidelines for the management of patients with acute myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol. 1999, 34: 890-911. 10.1016/S0735-1097(99)00351-4.View ArticlePubMedGoogle Scholar
- Braunwald E, Antman EL, Beasley JW, Califf RM, Cheitlin MD, Hochman JS, Jones RH, Kereiakes D, Kupersmith J, Levin TN, Pepine CJ, Schaeffer JW, Smith III EE, Steward DE, Theroux P: ACC/AHA guideline update for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients with Unstable Angina). J Am Coll Cardiol. 2002, 40: 1366-74. 10.1016/S0735-1097(02)02336-7.View ArticlePubMedGoogle Scholar
- Levy AR, O'Brien BJ, Sellors C, Grootendorst P, Willison D: Coding accuracy of administrative drug claims in the Ontario Drug Benefit database. Can J Clin Pharmacol. 2003, 10: 67-71.PubMedGoogle Scholar
- Quan J, Parson G, Ghali W: Validity of information on comorbidity derived from ICD-9-CM administrative data. Medical care. 2002, 40: 675-85. 10.1097/00005650-200208000-00007.View ArticlePubMedGoogle Scholar
- Tu JV, Austin PC, Naylor CD, Iron K, Zhang H: Acute myocardial infarction outcomes in Ontario. Cardiovascular health and services in Ontario: An ICES atlas. Edited by: Naylor CD, Slaughter PM. 1999, Toronto, Ontario: Institute for Clinical Evaluative Sciences, 83-110.Google Scholar
- Vermeulen MJ, Tu JV, Schull MJ: ICD-10 adaptations of the Ontario acute myocardial infarction mortality prediction rules performed as well as the original versions. J Clin Epidemiol. 2007, 60: 971-4. 10.1016/j.jclinepi.2006.12.009.View ArticlePubMedGoogle Scholar
- Masi R: Multiculturalism, medicine and health Part I: Multicultural health care. Can Fam Physician. 1988, 2173-2178.Google Scholar
- Waxler-Morrison N, Anderson J, Richardson E: Cross-cultural caring. A handbook for health professionals in Western Canada. 1990, Vancouver, BC: University of British Columbia PressGoogle Scholar
- Statistics Canada 2001 Census of Canada. [http://www12.statcan.ca/english/census01/products/analytic/companion/etoimm/canada.cfm#threefold_increase]
- Quan H, Wang F, Schopflocher D, Norris C, Galbraith PD, Faris P, Graham MM, Knudtson ML, Ghali WA: Development and validation of a surname list to define Chinese ethnicity. Medical Care. 2006, 44: 328-33. 10.1097/01.mlr.0000204010.81331.a9.View ArticlePubMedGoogle Scholar
- Harding S, Dew H, Simpson SL: The potential to identify South Asians using a computerized algorithm to classify names. Popul Trends. 1999, 97: 46-9.PubMedGoogle Scholar
- Cummins C, Winter H, Cheng KK, Maric R, Silcocks P, Varghese C: An assessment of the Nam Pehchan computer program for the identification of names of south Asian ethnic origin. J Public Health Med. 1999, 21: 401-6. 10.1093/pubmed/21.4.401.View ArticlePubMedGoogle Scholar
- Benner JS, Glynn RJ, Mogun H, Neumann PJ, Weinstein MC, Avorn J: Long-term persistence in use of statin therapy in elderly patients. JAMA. 2002, 288: 455-61. 10.1001/jama.288.4.455.View ArticlePubMedGoogle Scholar
- Balkrishnan R: Predictors of medication adherence in the elderly. Clin Ther. 1998, 20: 764-71. 10.1016/S0149-2918(98)80139-2.View ArticlePubMedGoogle Scholar
- Ammassari A, Trotta MP, Murri R, Castelli F, Narciso P, Noto P, Vecchiet J, Monforte A, Wu AW, Antinori A: Correlates and predictors of adherence to highly active antiretroviral therapy: overview of published literature. J Acquir Immune Defic Syndr. 2002, 31 (suppl 3): S123-7.View ArticlePubMedGoogle Scholar
- Schroeder K, Fahey T, Ebrahim S: Interventions for improving adherence to treatment in patients with high blood pressure in ambulatory settings. Cochrane Database of systematic reviews. 2004, CD004804-3Google Scholar
- Tu JV, Austin PC, Walld R, Roos L, Agras J, McDonald KM: Development and validation of the Ontario acute myocardial infarction mortality prediction rules. J Am Coll Cardiol. 2001, 37: 992-7. 10.1016/S0735-1097(01)01109-3.View ArticlePubMedGoogle Scholar
- Gislason GH, Rasmussen JN, Abildstrom SZ, Gadsboll N, Buch P, Friberg J, Rasmussen S, Kober L, Stender S, Madsen M, Torp-Pedersen C: Long-term compliance with beta-blockers, angiotensin-converting enzyme inhibitors, and statins after acute myocardial infarction. Eur Heart J. 2006, 27: 1153-8.View ArticlePubMedGoogle Scholar
- Britton A, Shipley M, Marmot M, Hemingway H: Does access to cardiac investigation and treatment contribute to social and ethnic differences in coronary heart disease? Whitehall II prospective cohort study. BMJ. 2004, 329: 318-23. 10.1136/bmj.38156.690150.AE.View ArticlePubMedPubMed CentralGoogle Scholar
- Lopez-Quintero C, Berry EM, Neumark Y: Limited English proficiency is a barrier to receipt of advice about physical activity and diet among Hispanics with chronic diseases in the United States. J Am Diet Assoc. 2009, 109: 1769-74. 10.1016/j.jada.2009.07.003.View ArticlePubMedGoogle Scholar
- King KM, LeBlanc P, Sanguins J, Mather C: Gender-based challenges faced by older Sikh women as immigrants: recognizing and acting on the risk of coronary artery disease. Can J Nurs Res. 2006, 38: 16-40.PubMedGoogle Scholar
- King KM, LeBlanc P, Carr W, Quan H: Chinese immigrants' management of their cardiovascular disease risk. West J Nurs Res. 2007, 29: 804-26. 10.1177/0193945906296431.View ArticlePubMedGoogle Scholar
- King KM, Mather CD, Sanguins J: Ethnocultural affiliation, gender, and cardiovascular disease risk management. Can J Cardiovasc Nurs. 2005, 15: 10-6.PubMedGoogle Scholar
- Washington G, Wang-Letzkus MF: Self-care practices, health beliefs, and attitudes of older diabetic Chinese Americans. J Health Hum Serv Adm. 2009, 32: 305-23.PubMedGoogle Scholar
- Lindesay J, Jagger C, Hibbett MJ, Peet SM, Moledina F: Knowledge, uptake and availability of health and social services among Asian Gujarati and white elderly persons. Ethn Health. 1997, 2: 59-69. 10.1080/13557858.1997.9961815.View ArticlePubMedGoogle Scholar
- Pieroni A, Sheikh QZ, Ali W, Torry B: Traditional medicines used by Pakistani migrants from Mirpur living in Bradford, Northern England. Complement Ther Med. 2008, 16: 81-6. 10.1016/j.ctim.2007.03.005.View ArticlePubMedGoogle Scholar
- Odegard PS, Gray SL: Barriers to medication adherence in poorly controlled diabetes mellitus. Diabetes Educ. 2008, 34: 692-7. 10.1177/0145721708320558.View ArticlePubMedGoogle Scholar
- Krousel-Wood MA, Muntner P, Joyce CJ, Islam T, Stanley E, Holt EW, Morisky DE, He J, Webber LS: Adverse effects of complementary and alternative medicine on antihypertensive medication adherence: findings from the cohort study of medication adherence among older adults. J Am Geriatr Soc. 2010, 58: 54-61. 10.1111/j.1532-5415.2009.02639.x.View ArticlePubMedPubMed CentralGoogle Scholar
- Li WW, Froelicher ES: Gender differences in Chinese immigrants: predictors for antihypertensive medication adherence. J Transcult Nurs. 2007, 18: 331-8. 10.1177/1043659607305194.View ArticlePubMedGoogle Scholar
- Li WW, Stotts NA, Froelicher ES: Compliance with antihypertensive medication in Chinese immigrants: cultural specific issues and theoretical application. Res Theory Nurs Pract. 2007, 21: 236-54. 10.1891/088971807782427967.View ArticlePubMedGoogle Scholar
- Health Canada safety information for rosuvastatin (Crestor). [http://www.hc-sc.gc.ca/ahc-asc/media/advisories-avis/_2005/2005_10-eng.php]
- Lau HS, de Boer A, Beuning KS, Porsius A: Validation of pharmacy records in drug exposure assessment. J Clin Epidemiol. 1997, 50: 619-625. 10.1016/S0895-4356(97)00040-1.View ArticlePubMedGoogle Scholar
- Steiner JF, Prochazka AV: The assessment of refill compliance using pharmacy records: methods, validity, and applications. J Clin Epidemiol. 1997, 50: 105-16. 10.1016/S0895-4356(96)00268-5.View ArticlePubMedGoogle Scholar
- West SL, Savitz DA, Koch G, Strom BL, Guess HA, Hartzema A: Recall accuracy for prescription medications: self-report compared with database information. Am J Epidemiol. 1995, 142: 1104-12.Google Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2261/11/56/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.