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Lawrence So
Steven G Morgan
Hude Quan


Ethnicity, prescription medication use, health surveys, concordance



Self-reported prescription medication use data is often used to measure differences across ethnic groups, but its accuracy may differ across ethnic groups.



We compared ethnic groups’ self-reported medication use to their administrative records for respondents with diabetes, hypertension, and asthma.



We linked the Canadian Community Health Survey to administrative prescription drug records for 17,191 respondents in British Columbia, Canada. We evaluated the concordance between self-reported medication use and prescription drug records using positive predictive value, negative predictive value, sensitivity, specificity, and kappa statistic for self-identified Whites, Chinese, South Asians, and Southeast Asians/Filipinos. The concordance was calculated using prescription drug records as the reference standard. We also estimated the odds of disagreement (either a false positive or negative) in medication use with logistic regressions for each ethnic group, and compared them using the Blinder- Oaxaca method.



We found that Chinese had the worst positive predictive value for asthma medication use at 0.41, while South Asians had the worst sensitivity for hypertension medication use at 0.60. The difference in reporting an error between ethnic groups was likely explained by differences in respondent characteristics. Particularly, if White respondents had the same characteristics as South Asians, then White respondents would have had 1.031 (95% CI: 1.020-1.041) higher odds of disagreement for hypertension medication use than with their own characteristics.



Self-reported medication use may be a valid measure of ethnic groups’ medication use if ethnic differences in characteristics, like household income are held constant. However, an important determinant of validity for all ethnic groups is whether medications are used routinely, or for a specific episode.

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1. Opolka JL, Rascati KL, Brown CM, et al. Ethnicity and prescription patterns for elderly Haloperidol, Risperidone, and Olanzapine. Psychiatr Serv 2004;55(2):151-6.
2. Roth MT, Esserman DA, Ivey JL, et al. Racial disparities in the quality of medication use in older adults: baseline findings from a longitudinal study. J Gen Intern Med 2009;25(3):228-34.
3. Zoratti EM, Havstad S, Rodriguez J, et al. Health service use by African Americans and Caucasians with asthma in a managed care setting. Am J Respir Crit Care Med 1998; 159:371-7.
4. Hahn BA. Children's health: racial and ethnic differences in the use of prescription medications. Pediatrics 1995;95(5):727-32.
5. Han E, Liu G. Racial disparities in prescription drug use for mental illness among population in US. J Ment Health Policy Econ 2005;8(3):131- 43.
6. Raji MA. Ethnic differences in antihypertensive medication use in the elderly. Ann Pharmacother 2004;38(2):209-14.
7. Gaskin DJ, Briesacher BA, Limcangco R, et al. Exploring racial and ethnic disparities in prescription drug spending and use among Medicare beneficiaries. Am J Geriatr Pharmacother 2006;4(2): 96-111.
8. Chen AY, Chang RK. Factors associated with prescription drug expenditures among children: an analysis of the Medical Expenditure Panel Survey. Pediatrics 2002;109(5):728-32.
9. Zukerman IH, Ryder PT, Simoni-Wastilla L, et al. Racial and ethnic disparities in the treatment of dementia among Medicare Beneficiaries. J Gerontol 2008;63B(5):S328-S333.
10. Crocker D, Brown C, Moolenaar R, et al. Racial and ethnic disparities in asthma medication usage and health-care utilization: data from the National Asthma Survey. Chest 2009;136(4):1063-71.
11. Horne R, Graupner L, Frost S, et al. Medicine in a multi-cultural society: the effect of cultural background on beliefs about medications. Soc Sci Med 2004;59(6):1307-13.
12. Bhandari A, Wagner T. Self-reported utilization of health care services: improving measurement and accuracy. Med Care Res Rev 2006;63(2):217-35.
13. Gordon NP, Wortley PM, Singleton JA, et al. Race/ethnicity and validity of self-reported pneumococcal vaccination. BMC Public Health 2008;8:227.
14. Giles WH, Croft JB, Keenan NL, et al. The validity of self-reported hypertension and correlates of hypertension awareness among blacks whites within the stroke belt. Am J Prev Med 1995;11: 163-9.
15. Leung B, Luo N, So L, et al. Comparing three measures of health status (perceived health with Likert-type scale, EQ-5D, and number of chronic conditions) in Chinese and white Canadians. Med Care 2007;45(7):610-7.
16. Lee JW, Jones PS, Mineyama Y, et al. Cultural differences in responses to a Likert scale. Res Nurs Health 2002;25:295-306.
17. Uiters E, Van Dijk L, Deville W, et al. Ethnic minorities and prescription medication; concordance between self-reports and medical records. BMC Health Serv Res 2006;6(115).
18. Reijneveld SA. The cross-cultural validity of self-reported use of health care: a comparison of survey and registration data. J Clin Epidemiol 2000;53:267-72.
19. Statistics Canada. Canadian Community Health Survey 2003: User Guide for the Public Use Microdata File. Ottawa: Ministry of Industry, 2003.
20. Statistics Canada. Canadian Community Health Survey 2005: User Guide for the Public Use Microdata File. Ottawa: Ministry of Industry, 2005.
21. Béland Y. Canadian community health survey-- methodological overview. Health Reports 2002;13(3):9-14.
22. Battern D, Brisebois F. Combining health surveys: a user guide. Statistics Canada; 2005.
23. World Health Organization. Guidelines for ATC classification and DDD assignment 2004. Oslo, Norway: WHO Collaborating Centre for Drug Statistics Methodology; 2004.
24. Hanley GE, Morgan S, Reid RJ. Explaining prescription drug use and expenditures using the adjusted clinical groups case-mix system in the population of British Columbia, Canada. Med Care 2010;48(5):402-8.
25. DeMaris A. Regression with social data: Modeling continuous and limited response variables. Hoboken, NJ: John Wiley & Sons, Inc.; 2004.
26. McGinn T, Weyer PC, Newman TB, et al. Tips for learners of evidence based medicine: 3. Measures of observer variability (kappa statistic). CMAJ 2004;171(11):1369-73.
27. Blinder AS. Wage discrimination: reduced form and structural estimates. J Hum Res 1973;8:435- 55.
28. Oaxaca RL. Male-female wage differentials in urban labor markets. Int Econ Rev 1973;14:693- 709.
29. Daymont TN, Andrisani PJ. Job preferences, college major, and the gender gap in earnings. J Hum Resour 1984;19(3):408-28.
30. Bauer TK, Sinning M. An extension of the Blinder-Oaxaca decomposition to non-linear models. RWI Discussion Paper 2006;49.
31. Hunt S, Bhopal R. Self reports in research with non-English speakers. BMJ 2003;327:352-3.
32. Creatore MI, Moineddin R, Booth G, et al. Ageand sex-related prevalence of diabetes mellitus among immigrants to Ontario, Canada. CMAJ Early Release: April 19, 2010.