Cardiovascular Risk Stratification Among University Employees in India: Comparison of WHO/ISH, ASCVD and Framingham Risk Models

Background Cardiovascular disease (CVD) risk prediction is an important component of primary prevention, particularly in populations with increasing cardiometabolic risk. Several risk prediction models are available, but their estimates may differ because of differences in derivation populations, predictors, calibration, and cardiovascular outcomes. Evidence comparing these models within Indian occupational populations remains limited. This study compared 10-year CVD risk estimates generated by the World Health Organization/International Society of Hypertension (WHO/ISH) cardiovascular risk charts, the American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort Equation (ASCVD-PCE), and the Framingham general cardiovascular disease risk equation among university employees in India. Methods A comparative observational study was conducted using standardized health assessment data from 266 university employees. Participants aged 40-74 years were selected to provide a common analytical age range across the three risk prediction approaches. Of 127 employees within this age range, three with documented previous ischemic heart disease were excluded because the analysis focused on primary prevention. The final analytical cohort comprised 124 participants. Blood pressure was assessed using a standardized protocol involving three readings at five-minute intervals, with repeat assessments during three subsequent weekly visits for employees with elevated initial readings. Ten-year cardiovascular risk was estimated using the 2019 WHO/ISH laboratory-based risk charts for the South Asian region, the ASCVD-PCE, and the 2008 Framingham general CVD equation. Agreement between risk categories was assessed using Cohen's kappa and linear weighted kappa. Agreement was also examined at [≥]10% and [≥]20% thresholds. Results The mean age of the 124 participants was 47.63 {+/-} 6.45 years, and 86.3% were male. Diabetes was present in 25.8%, smoking/tobacco use in 19.4%, and 29.0% were receiving antihypertensive treatment. Mean estimated risk was 5.94% for WHO/ISH, 5.95% for ASCVD-PCE, and 12.86% for Framingham. High risk ([≥]20%) was identified in 2.4%, 4.8%, and 20.2% of participants by WHO/ISH, ASCVD-PCE, and Framingham, respectively. Exact four-category agreement was 70.2% between WHO/ISH and ASCVD-PCE, compared with 31.5% between WHO/ISH and Framingham and 26.6% between ASCVD-PCE and Framingham. Cohen's kappa was 0.502 for WHO/ISH versus ASCVD-PCE, 0.079 for WHO/ISH versus Framingham, and 0.047 for ASCVD-PCE versus Framingham. Weighted kappa values were 0.639, 0.323, and 0.342, respectively. Conclusion WHO/ISH and ASCVD-PCE produced closely similar mean risk estimates and substantially greater categorical agreement than either model showed with the Framingham equation. Framingham generated considerably higher 10-year CVD risk estimates and classified a larger proportion of participants into higher-risk categories. These findings highlight the importance of model selection when cardiovascular risk assessment is undertaken in Indian occupational populations and support cautious interpretation of risk estimates derived from models developed in different populations and for different cardiovascular endpoints. Keywords: cardiovascular disease; risk prediction; WHO/ISH; ASCVD; Pooled Cohort Equation; Framingham; India; occupational health; university employees; risk classification