Mora S, et al. - In the present study, researchers assessed the predictive accuracy of the pooled cohort equations (PCEs) in the Women’s Health Initiative (WHI), a multiethnic cohort of contemporary US postmenopausal women, as well as the impacts of time-varying treatments such as aspirin and statins, and ascertainment of additional atherosclerotic cardiovascular disease (ASCVD) events via linkage with the Centers for Medicare and Medicaid Services (CMS) claims. Findings revealed that observed risks in the WHI were lower than predicted by PCE as noted in several other US cohorts without including surveillance for ASCVD events using CMS, but risks were better aligned after including CMS events.

Methods

• The WHI enlisted the largest number of US women (n = 161,808) with the racial/ethnic, geographic, and age diversity of the general population (1993-1998).
• 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 were included.
• Median follow-up was 10 years.
• ASCVD was characterized as myocardial infarction, stroke, or cardiovascular death.

Results

• As per data, among the 19,995 women (mean [SD] age, 64 [7.3] years; 8,305 [41.5%] white, 7,688 [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 1,236 ASCVD events occurred in 10 years and were adjudicated through medical record review by WHI investigators.
• Findings revealed that the WHI-adjudicated observed risks were lower than predicted.
• Researchers found that 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.
• They noted small changes after adjusting for time-dependent changes in statin and aspirin use.
• Data reported that WHI-adjudicated risks were also lower than forecasted, but observed (predicted) risks became aligned after involving 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 among women 65 years or older enrolled in Medicare.
• Similar outcomes were seen across ethnic/racial groups.
• They discovered that the equations discriminated risk well (C statistic, 0.726; 95% CI, 0.714-0.738).