Comparison of Lifestyle Based to Traditional CVD Prediction in a Multiethnic Cohort of Non-Smoking Women
Background—Healthy levels of lifestyle factors can reduce risk of CVD. However, except for smoking status, often considered a traditional risk factor, their effect on cardiovascular risk prediction is unclear.
Methods and Results—We used a case-cohort design of post-menopausal non-smokers in the multiethnic Women's Health Initiative Observational Study (1587 cases and 1808 sub-cohort participants) with a median follow-up of 10 years in non-cases. Compared to non-smokers with no other healthy lifestyle factors (healthy diet, recreational physical activity, moderate alcohol use, and low adiposity), the risk of cardiovascular disease was lower for each additional factor (hazard ratio for trend 0.82; 95% CI 0.76, 0.89), with a 45% reduction in risk with all factors (95% CI 0.36, 0.84). When lifestyle factors were added to traditional risk factor models (variables from the Pooled Cohort and Reynolds risk scores), only recreational physical activity remained independently associated with risk of cardiovascular disease. The addition of detailed lifestyle measures to traditional models showed a change in the Integrated Discrimination Improvement and continuous Net Reclassification Index (p < 0.01 for both), but had little impact on more clinically relevant risk stratification measures.
Conclusions—While lifestyle factors have important effects on CVD risk factors and subsequent risk, their addition to established CVD risk models does not result in clear improvement in overall prediction.
- Received July 1, 2014.
- Accepted August 6, 2014.