Estimation of Atherosclerotic Cardiovascular Disease Risk Among Patients in the Veterans Affairs Health Care System

• Type of Material: Article
• Authors: Jason L. Vassy, Veterans Affairs Boston Healthcare System; Bing Lu, Veterans Affairs Boston Healthcare System; Yuk-Lam Ho, Veterans Affairs Boston Healthcare System; Ashley Galloway, Veterans Affairs Boston Healthcare System; Sridharan Raghavan, Veterans Affairs Eastern Colorado Healthcare System; Jacqueline Honerlaw, Veterans Affairs Boston Healthcare System; Laura Tarko, Veterans Affairs Boston Healthcare System; John Russo, Veterans Affairs Boston Healthcare System; Saadia Qazi, Veterans Affairs Boston Healthcare System; Ariela R. Orkaby, Veterans Affairs Boston Healthcare System; Vidisha Tanukonda, Boston University; Luc Djousse, Veterans Affairs Boston Healthcare System; J. Michael Gaziano, Veterans Affairs Boston Healthcare System; David R. Gagnon, Veterans Affairs Boston Healthcare System; Kelly Cho, Veterans Affairs Boston Healthcare System; Peter Wilson, Emory University
• Language: English
• Date: 2020-07-14
• Publisher: American Medical Association
• Publication Version: Final Published Version
• Copyright Statement: © 2020 Vassy JL et al. JAMA Network Open.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1001/jamanetworkopen.2020.8236
• Title of Journal or Parent Work: JAMA Network Open
• Volume: 3
• Issue: 7
• Start Page: e208236
• End Page: e208236
• Grant/Funding Information: This research was supported by the US Department of Veterans Affairs Merit Award I01 CX001025 and Career Development Award IK2 CX001262.; Support for Veterans Affairs/Centers for Medicare & Medicaid Services data provided by the Department of Veterans Affairs, Veterans Affairs Health Services Research, and Development Service, VA Information Resource Center under project numbers SDR 02-237 and 98-004.
• Keywords: Score; Validation; Pooled cohort; Life Sciences & Biomedicine; General & Internal Medicine; Equations; Prediction; Medicine, General & Internal; Science & Technology
• Research Categories: Biology, Biostatistics; Health Sciences, Medicine and Surgery; Health Sciences, Health Care Management

Abstract

Importance Current guidelines recommend statin therapy for millions of US residents for the primary prevention of atherosclerotic cardiovascular disease (ASCVD). It is unclear whether traditional prediction models that do not account for current widespread statin use are sufficient for risk assessment. Objectives To examine the performance of the Pooled Cohort Equations (PCE) for 5-year ASCVD risk estimation in a contemporary cohort and to test the hypothesis that inclusion of statin therapy improves model performance. Design, Setting, and Participants This cohort study included adult patients in the Veterans Affairs health care system without baseline ASCVD. Using national electronic health record data, 3 Cox proportional hazards models were developed to estimate 5-year ASCVD risk, as follows: the variables and published β coefficients from the PCE (model 1), the PCE variables with cohort-derived β coefficients (model 2), and model 2 plus baseline statin use (model 3). Data were collected from January 2002 to December 2012 and analyzed from June 2016 to March 2020. Exposures Traditional ASCVD risk factors from the PCE plus baseline statin use. Main Outcomes and Measures Incident ASCVD and ASCVD mortality. Results Of 1 672 336 patients in the cohort (mean [SD] baseline age 58.0 [13.8] years, 1 575 163 [94.2%] men, 1 383 993 [82.8%] white), 312 155 (18.7%) were receiving statin therapy at baseline. During 5 years of follow-up, 66 605 (4.0%) experienced an ASCVD event, and 31 878 (1.9%) experienced ASCVD death. Compared with the original PCE, the cohort-derived model did not improve model discrimination in any of the 4 age-sex strata but did improve model calibration. The PCE overestimated ASCVD risk compared with the cohort-derived model; 211 237 of 1 136 161 white men (18.6%), 29 634 of 218 463 black men (13.6%), 1741 of 44 399 white women (3.9%), and 836 of 16 034 black women (5.2%) would be potentially eligible for statin therapy under the PCE but not the cohort-derived model. When added to the cohort-derived model, baseline statin therapy was associated with a 7% (95% CI, 5%-9%) lower relative risk of ASCVD and a 25% (95% CI, 23%-28%) lower relative risk for ASCVD death. Conclusions and Relevance In this study, lower than expected rates of incident ASCVD events in a contemporary national cohort were observed. The PCE overestimated ASCVD risk, and more than 15% of patients would be potentially eligible for statin therapy based on the PCE but not on a cohort-derived model. In the statin era, health care professionals and systems should base ASCVD risk assessment on models calibrated to their patient populations.