AMBREEN RAZA MBBS VARUN MALAYALA MBBS, MPH University at Buffalo/Sisters of Charity Hospital
Conflict of interest: None Financial disclosures: None
United States Preventive Services Taskforce (USPSTF) recommends prescribing aspirin for men aged 45 to 79 years when the potential benefit of reduction in coronary artery disease (CAD) outweighs the potential harm of gastrointestinal hemorrhage. Grade A recommendation (net benefit >> risk) A 10-year CAD risk (calculated using Framingham risk score) of >4% in 45-59 year age group >9% in 60-69 year age group >12% in 70-79 year age group is considered a threshold to define potential benefit
Five prospective, randomized clinical trials conducted by independent researchers in different countries established the effectiveness of low dose Aspirin in the prevention of first CVD event.
These trials studied a combined total of 100,000 patients for a total of approximately 700,000 person-years. Based on the overwhelming data USPSTF recommended low dose ASA for all adults in 2002. In 2009 USPSTF issued gender specific guidelines regarding low dose aspirin for the prevention of CAD in men whereas CVA in women.
The primary objective of this study is to assess the compliance with USPSTF recommendations on aspirin intake for primary prevention of coronary artery disease in men. Secondary goal is to evaluate the factors that might effect the compliance with aspirin.
INCLUSION CRITERIA Males between the ages of 45-79 years No previous history of CVD Should have at least 4-12% ten year risk of CAD as computed by Framingham risk score using the following parameters ; age, total cholesterol, HDL cholesterol, smoking history and systolic blood pressure. EXCLUSION CRITERIA Males younger than 45 older than 79 All Females Previous history of CVD Less than 4 % ten year risk of CAD per Framingham's risk criteria
The study utilized 2011-12 National Health and Nutrition Examination Survey (NHANES) national level datasets from the Center for Disease Control (CDC). The NHANES survey includes interviews, health examination and blood draws taken after an overnight fast of 9 hours. Framingham risk score was calculated for all the participants using the online National, Heart, Lung and Blood Institute (NHLBI) risk score calculator.
Participants meeting criteria to take ASA were identified. Characteristics of patients influencing the prescription and compliance were identified in the analyses. SPSS (version 21.0, SPSS Inc., Chicago, Ill) was used for analysis & p- value < 0.05 was considered as a statistically significant. Chi-square test and Independent samples t-test were used for categorical and continuous variables respectively
9756 (TOTAL NHANES 2011-12 SAMPLE) 1362 (13.9%) (MEN, AGED 45-79) CAD=85 MI=85 CVA=80 ANGINA=46 MISSING DATA=154 1001 (10.2%) (FINAL SAMPLE) 916 (91.5%) MEET CRITERIA TO TAKE ASPIRIN 85 (8.5%)DON T MEET CRITERIA TO TAKE ASA
100% 7.2 10.7 7.9 8.5 80% 92.8 89.3 92.1 91.5 Do not meet criteria to take aspirin Meet criteria to take aspirin 60%
Table 1: Baseline Characteristics Of Patients
Fig 3: Flow chart showing erroneous trends in the Rx of aspirin
Fig 4 : Flow chart depicting variance in patient compliance 202/916 (22.1%) Compliant! Really?
Table2:Patient Characteristics Governing Physicians Decision To Prescribe ASA
Table 3: Patient Characteristics: Markers of adherence to Rx of ASA
The issues regarding adherence to low dose aspirin for primary prophylaxis against coronary artery disease are complicated. Simplistic terms such as patient non compliance or under prescription paint an incomplete picture of the problem. Physicians tend to offer primary prophylaxis more often to patients who have obvious risk factors rather than based on established criteria.
On the part of physicians there is poor perceived susceptibility of coronary artery diseases in younger patient population. Although younger patients do meet criteria for primary prophylaxis against CAD, physicians tend to overlook their risk factors! Ironically this patient population should rather be targeted more aggressively for primary prevention. This will reduce morbidity and mortality ensuing from coronary artery diseases and burden of health care cost in the future.
There is poor understanding on the part of patients regarding the dose and frequency of aspirin for primary prophylaxis. Physicians need to ask for more details when the answer to Do you take low dose aspirin? is a YES. Patient s with fewer medications and younger age group tend to be less compliant.
Inappropriate prescription of aspirin and a very high compliance rate in patients who DO NOT meet the criteria for primary prophylaxis is a glaring concern. It is unnecessarily exposing a section of the population to the risks of adverse effects including gastrointestinal bleed.
The biggest strength of this study is using a national level data set. Large sample size. This is the first and the only study which has evaluated the prescription and compliance of aspirin for primary prophylaxis in men aged 45-79 years using a national level database. Extensive questionnaire was employed to collect information. Wide number of variables further enhanced the strength of the study.
The study relies on a cross sectional data and a causal relation might not be exactly established between the demographic factors and compliance on ASA Data collection was not blinded.
Ademi, Z., et al. (2013). "Is it cost-effective to increase aspirin use in outpatient settings for primary or secondary prevention? Simulation data from the REACH Registry Australian Cohort." Cardiovasc Ther 31(1): 45-52. Al Omari, M., et al. (2012). "Knowledge, attitudes and current practice of Jordanian family physicians about prescribing aspirin in primary and secondary prevention of vascular diseases: a self-reported survey." Eur J Cardiovasc Nurs 11(1): 9-13. Badri, M., et al. (2012). "The role of aspirin in primary prevention of vascular events." Am J Med 125(12): e11. Burkholder, G. A., et al. (2012). "Underutilization of aspirin for primary prevention of cardiovascular disease among HIV-infected patients." Clin Infect Dis 55(11): 1550-1557. Cartledge, B. (2013). "Aspirin for primary prevention: no." J Prim Health Care 5(2): 174. Cook, N. R., et al. (2012). "Aspirin in the primary prevention of cardiovascular disease in the Women's Health Study: effect of noncompliance." Eur J Epidemiol 27(6): 431-438. Ward, S. A., et al. (2012). "Aspirin for primary prevention of cardiovascular events in the elderly: current status and future directions." Drugs Aging 29(4): 251-258. VanWormer, J. J., et al. (2012). "Aspirin for primary prevention of CVD: are the right people using it?" J Fam Pract 61(9): 525-532.
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