Evaluation of the Pooled Cohort Risk Equations for Cardiovascular Risk Prediction in a Multiethnic Cohort From the Women's Health Initiative

• Type of Material: Article
• Authors: Samia Mora, Harvard Medical School; Nanette Wenger, Emory University; Nancy R. Cook, Harvard Medical School; Jingmin Liu, Fred Hutchinson Cancer Research Center; Barbara V. Howard, MedStar Health Research Institute; Marian C. Limacher, University of Florida; Simin Liu, Brown University; Karen L. Margolis, HealthPartners Institute; Lisa W. Martin, George Washington University; Nina P. Paynter, Harvard Medical School; Paul M. Ridker, Harvard Medical School; Jennifer G. Robinson, University of Iowa; Jacques E. Rossouw, National Institutes of Health; Monika M. Safford, Weill Cornell Medical College; JoAnn E. Manson, Harvard Medical School
• Language: English
• Date: 2018-09-01
• Publisher: American Medical Association (AMA)
• Publication Version: Final Published Version
• Copyright Statement: © 2018 American Medical Association. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1001/jamainternmed.2018.2875
• Title of Journal or Parent Work: JAMA Internal Medicine
• ISSN: 2168-6106
• Volume: 178
• Issue: 9
• Start Page: 1231
• End Page: 1240
• Grant/Funding Information: The WHI Program is funded by the NHLBI, National Institutes of Health, Department of Health and Human Services through contracts N01WH22110, 24152, 32100-2, 32105-6, 32108-9, 32111-13, 32115, 32118-32119, 32122, 42107-26, 42129-32, 44221,HHSN268201600018C, HHSN268201600001C, HHSN268201600002C, HHSN268201600003C, and HHSN268201600004C.; Dr Mora received funding through the NHLBI K24 HL136852 and HL134811.
• Keywords: STATINS; OUTCOMES; General & Internal Medicine; Medicine, General & Internal; PREVENTION; HIPAA PRIVACY RULE; Science & Technology; CORONARY-HEART-DISEASE; CALIBRATION; VALIDATION; MEDICARE CLAIMS; ADJUDICATION; GUIDELINES; Life Sciences & Biomedicine
• Research Categories: Health Sciences, Medicine and Surgery; Biology, Biostatistics

Abstract

IMPORTANCE Atherosclerotic cardiovascular disease (ASCVD) kills approximately 1 in every 3 US women. Current cholesterol, hypertension, and aspirin guidelines recommend calculating 10-year risk of ASCVD using the 2013 Pooled Cohort Equations (PCE). However, numerous studies have reported apparent overestimation of risk with the PCE, and reasons for overestimation are unclear. OBJECTIVE We evaluated the predictive accuracy of the PCE in the Women's Health Initiative (WHI), a multiethnic cohort of contemporary US postmenopausal women. We evaluated the effects of time-varying treatments such as aspirin and statins, and ascertainment of additional ASCVD events by linkage with the Centers for Medicare and Medicaid Services (CMS) claims. DESIGN, SETTING, AND PARTICIPANTS The WHI recruited the largest number of US women (n = 161 808) with the racial/ethnic, geographic, and age diversity of the general population (1993-1998). For this study, we included women aged 50 to 79 (n = 19 995) participating in the WHI with data on the risk equation variables at baseline and who met the guideline inclusion and exclusion criteria. Median follow-up was 10 years. MAIN OUTCOMES AND MEASURES For this study, ASCVD was defined as myocardial infarction, stroke, or cardiovascular death. RESULTS Among the 19 995 women (mean [SD] age, 64 [7.3] years; 8305 [41.5%] white, 7688 [38.5%] black, 3491 [17.5%] Hispanic, 103 [0.5%] American Indian, 321 [1.6%] Asian/Pacific Islander, and 87 [0.4%] other/unknown), a total of 1236 ASCVD events occurred in 10 years and were adjudicated through medical record review by WHI investigators. The WHI-adjudicated observed risks were lower than predicted. The observed (predicted) risks for baseline 10-year risk categories less than 5%, 5% to less than 7.5%, 7.5% to less than 10%, and 10% or more were 1.7 (2.8), 4.4 (6.2), 5.3 (8.7), and 12.4 (18.2), respectively. Small changes were noted after adjusting for time-dependent changes in statin and aspirin use. Among women 65 years or older enrolled in Medicare, WHI-adjudicated risks were also lower than predicted, but observed (predicted) risks became aligned after including events ascertained by linkage with CMS for additional surveillance for events: 3.8 (4.3), 7.1 (6.4), 8.3 (8.7), and 18.9 (18.7), respectively. Similar results were seen across ethnic/racial groups. Overall, the equations discriminated risk well (C statistic, 0.726; 95% CI, 0.714-0.738). CONCLUSIONS AND RELEVANCE Without including surveillance for ASCVD events using CMS, observed risks in the WHI were lower than predicted by PCE as noted in several other US cohorts, but risks were better aligned after including CMS events.