Aspirin for primary prevention of CVD: Are the right people using it?

,; ,; ,; ,; ,; ,; ,

Original Research

Aspirin for primary prevention of CVD: Are the right people using it?

J Fam Pract. 2012 September;61(9):525-533

PDF Download

References

1. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics—2011 update: a report from the American Heart Association. Circulation. 2011;123:e18-e209.

2. Heidenreich PA, Trogdon JG, Khavjou OA, et al. Forecasting the future of cardiovascular disease in the United States: a policy statement from the American Heart Association. Circulation. 2011;123:933-944.

3. Sullivan PW, Ghushchyan V, Wyatt HR. The medical cost of cardiometabolic risk factor clusters in the United States. Obesity. 2007;15:3150-3158.

4. Pearson TA, Blair SN, Daniels SR, et al. AHA guidelines for primary prevention of cardiovascular disease and stroke: 2002 update. American Heart Association Science Advisory and Coordinating Committee. Circulation. 2002;106:388-391.

5. Kriekard P, Gharacholou SM, Peterson ED. Primary and secondary prevention of cardiovascular disease in older adults: a status report. Clin Geriatr Med. 2009;25:745-755.

6. Ford ES, Ajani UA, Croft JB, et al. Explaining the decrease in US deaths from coronary disease, 1980-2000. N Engl J Med. 2007;356:2388-2398.

7. Hennekens CH, Schneider WR. The need for wider and appropriate utilization of aspirin and statins in the treatment and prevention of cardiovascular disease. Expert Rev Cardiovasc Ther. 2008;6:95-107.

8. Barnett H, Burrill P, Iheanacho I. Don’t use aspirin for primary prevention of cardiovascular disease. BMJ. 2010;340:c1805.-

9. Sanchez-Ross M, Waller AH, Maher J, et al. Aspirin for the prevention of cardiovascular morbidity. Minerva Med. 2010;101:205-214.

10. S. Preventive Services Task Force. Aspirin for the prevention of cardiovascular disease: US preventive services task force recommendation statement. Ann Intern Med. 2009;150:396-404.

11. Bartolucci AA, Tendera M, Howard G. Meta-analysis of multiple primary prevention trials of cardiovascular events using aspirin. Am J Cardiol. 2011;107:1796-1801.

12. Maciosek MV, Coffield AB, Edwards NM, et al. Priorities among effective clinical preventive services: results of a systematic review and analysis. Am J Prev Med. 2006;31:52-61.

13. Pignone M, Anderson GK, Binns K, et al. Aspirin use among adults aged 40 and older in the United States results of a national survey. Am J Prev Med. 2007;32:403-407.

14. Ajani UA, Ford ES, Greenland KJ, et al. Aspirin use among US adults: behavioral risk factor surveillance system. Am J Prev Med. 2006;30:74-77.

15. Sanchez DR, Diez Roux AV, Michos ED, et al. Comparison of the racial/ethnic prevalence of regular aspirin use for the primary prevention of coronary heart disease from the multi-ethnic study of atherosclerosis. Am J Cardiol. 2011;107:41-46.

16. Stafford RS, Monti V, Ma J. Underutilization of aspirin persists in US ambulatory care for the secondary and primary prevention of cardiovascular disease. PLoS Med. 2005;2:e353.-

17. Rodondi N, Vittinghoff E, Cornuz J, et al. Aspirin use for the primary prevention of coronary heart disease in older adults. Am J Med. 2005;118(suppl):1288e1-1288e9.

18. Rodondi N, Cornuz J, Marques-Vidal P, et al. Aspirin use for the primary prevention of coronary heart disease: a population-based study in Switzerland. Prev Med. 2008;46:137-144.

19. Nieto FJ, Peppard PE, Engelman CD, et al. The Survey of the Health of Wisconsin (SHOW), a novel infrastructure for population health research: rationale and methods. BMC Public Health. 2010;10:785.-

20. D’Agostino RB, Sr, Vasan RS, Pencina MJ, et al. General cardiovascular risk profile for use in primary care: the Framingham Heart Study. Circulation. 2008;117:743-753.

21. Cody RP, Smith JK. Applied Statistics and the SAS Programming Language. New York, NY: Prentice Hall; 2005.

22. Mallonee S, Daniels CG, Mold JW, et al. Increasing aspirin use among persons at risk for cardiovascular events in Oklahoma. J Okla State Med Assoc. 2010;103:254-260.

23. Centers for Disease Control and Prevention (CDC). Prevalence of aspirin use to prevent heart disease—Wisconsin, 1991, and Michigan, 1994. MMWR Morb Mortal Wkly Rep. 1997;46:498-502.

24. US Preventive Services Task Force. Aspirin for the primary prevention of cardiovascular events: recommendation and rationale. Ann Intern Med. 2002;136:157-160.

25. Werner M, Kelsberg G, Weismantel AM. Which healthy adults should take aspirin? J Fam Pract. 2004;53:146-150.

26. Berger JS, Roncaglioni MC, Avanzini F, et al. Aspirin for the primary prevention of cardiovascular events in women and men: a sex-specific meta-analysis of randomized controlled trials. JAMA. 2006;295:306-313.

27. McQuaid KR, Laine L. Systematic review and meta-analysis of adverse events of low-dose aspirin and clopidogrel in randomized controlled trials. Am J Med. 2006;119:624-638.

28. VanWormer JJ, Johnson PJ, Pereira RF, et al. The Heart of New Ulm project: using community-based cardiometabolic risk factor screenings in a rural population health improvement initiative. Popul Health Manag. 2012;15:135-143.

29. Jeffreys D. Aspirin: The Remarkable Story of a Wonder Drug. New York, NY: Bloomsbury Publishing; 2005.

30. Smith NL, Psaty BM, Heckbert SR, et al. The reliability of medication inventory methods compared to serum levels of cardiovascular drugs in the elderly. J Clin Epidemiol. 1999;52:143-146.

31. Hedman J, Kaprio J, Poussa T, et al. Prevalence of asthma, aspirin intolerance, nasal polyposis and chronic obstructive pulmonary disease in a population-based study. Int J Epidemiol. 1999;28:717-722.

Initially, we created univariate models to gauge the crude relationship between each variable and aspirin use. Any variable with P<.20 in its univariate association with regular aspirin use was considered for inclusion in the final multivariate regression model. In the multivariate analyses, we sequentially eliminated variables with the weakest association with aspirin use until only significant (P<.10) independent predictors remained. Appropriate weighting was applied based on survey strata and cluster structure.¹⁹

Results

Of the 831 participants who met the eligibility criteria for our analysis, 268 (32%) had an aspirin indication. TABLE 1 shows the key characteristics of the analytical sample, stratified by those for whom aspirin was indicated and those for whom it was not. The sample was primarily middle-aged (mean age 52.4±0.36) and non-Hispanic white (93%). Compared with those for whom aspirin therapy was not indicated, the group with an aspirin indication was significantly older (56.9 vs 50.3) and had a significantly higher proportion of males (97% vs 19%). As expected, those for whom aspirin was indicated were also at higher risk for CHD and stroke, most notably as a result of significantly higher systolic BP (131.9 vs 121.5 mm Hg) and lower HDL cholesterol (42.5 vs 52.6 mg/dL) compared with participants without an aspirin indication.

TABLE 1
Study sample, by sociodemographic variable and aspirin indication

Variable	Full sample (N=831)	Aspirin indicated (n=268)	Aspirin not indicated (n=563)
Mean age, y	52.4	56.9	50.3
Sex, n Male Female	367 464	259 9	108 455
Race/ethnicity, n White, non-Hispanic Nonwhite/Hispanic	776 55	252 16	524 39
Marital status, n Married/partnered Not married or partnered	637 194	215 53	422 141
Health insurance, n Uninsured Insured	76 755	26 242	50 513
Education, n ≤High school Associate’s degree ≥Bachelor’s degree	217 312 302	77 107 84	140 205 218
Employment, n Unemployed Student/retiree/home Employed	98 147 586	33 52 183	65 95 403

When aspirin was indicated, use was linked to age and sex
In the group with an aspirin indication (n=268), 83 (31%) reported taking aspirin most days of the week. The initial examination of sociodemographic variables showed that age, sex, and employment status demonstrated significant univariate associations with regular aspirin use ( TABLE 2 ). In the multivariate model, however, the odds of regular aspirin use were significantly greater among participants who were older (odds ratio [OR], 1.07; P<.001) or female (OR, 3.49; P=.021) compared with participants who were younger or male, respectively.

TABLE 2
Participants who have an aspirin indication: Association between sociodemographic variables and regular aspirin use

Variable	Regular aspirin use, OR (95% CI)	P value*
Age Older vs younger	1.07 (1.04-1.11)	.001
Sex Female vs male	3.89 (1.42-10.67)^†	.008
Race/ethnicity Nonwhite/Hispanic vs white non-Hispanic	0.55 (0.09-3.47)	.526
Marital status Not married/partnered vs married/partner	0.83 (0.36-1.95)	.678
Health insurance Uninsured vs insured	0.86 (0.50-1.47)	.579
Education ≥Bachelor’s degree vs ≤high school Associate’s degree/some college vs ≤high school	1.58 (0.75-3.34) 1.36 (0.74-2.49)	.234 .325
Employment Student or retired vs employed Unemployed vs employed	2.96 (1.74-5.03) 0.62 (0.25-1.56)	.001 .314
*Significance was defined as P<.10. ^†Multivariate adjusted model: 3.49 (95% CI, 1.21-10.07; P=.021). CI, confidence interval; OR, odds ratio.

When aspirin was not indicated, age and sex still affected use
Among the 563 participants for whom aspirin therapy was not indicated, 102 (18%) reported taking aspirin regularly. Age, sex, race/ethnicity, health insurance, and employment ( TABLE 3 ), as well as region of residence and study enrollment year, had significant univariate associations with regular aspirin use; these variables were tested for potential inclusion in the multivariate model. In the final multivariate regression model, the odds of regular aspirin use were significantly greater among participants who were older (OR, 1.07; P<.001) and significantly lower among participants who were Hispanic or nonwhite (OR, 0.32; P=.063).

TABLE 3
Participants who do not have an aspirin indication: Association between sociodemographic variables and regular aspirin use

Variable	Regular aspirin use, OR (95% CI)	P value*
Age Older vs younger	1.07 (1.04-1.10)	.001
Sex Female vs male	1.60 (0.84-3.04)	.152
Race/ethnicity Nonwhite or Hispanic vs white non-Hispanic	0.23 (0.07- 0.73)^†	.013
Marital status Not married/partnered vs married/partnered	1.00 (0.63-1.59)	.992
Health insurance Uninsured vs insured	0.36 (0.11- 1.15)	.086
Education Bachelor’s or higher vs high school or less Associate’s/some college vs high school or less	0.74 (0.35-1.57) 0.67 (0.38-1.17)	.431 .158
Employment Student/retired vs employed Unemployed vs employed	2.35 (1.32-4.20) 0.78 (0.26- 2.34)	.004 .652
*Significance was defined as P<.10. ^†Multivariate adjusted model: 0.32 (95% CI, 0.10-1.06; P=.063). CI, confidence interval; OR, odds ratio.

Discussion

Aspirin was generally underutilized in the group with significant CVD risk (n=268) in our study, with slightly less than a third of participants for whom aspirin therapy was indicated taking it most days of the week. Despite trends of increased aspirin use among US adults in recent years,¹⁵ aspirin therapy in the 2008-2010 SHOW sample was lower than in 2005 to 2008. It was also lower than national estimates of aspirin use for primary CVD prevention^15,22—but about 20% higher than estimates of overall aspirin use in Wisconsin 20 years ago.²³ Consistent with previous research, the final adjusted model and sensitivity analysis indicated that older individuals were more likely to take aspirin regularly.