Development and Validation of a Coronary Risk Prediction Model for Older U.S. and European Persons in the Cardiovascular Health Study and the Rotterdam Study
Annals of Internal Medicine , Volume 157 - Issue 6 p. 389- 397
Background: Risk scores for prediction of coronary heart disease (CHD) in older adults are needed. Objective: To develop a sex-specific CHD risk prediction model for older adults that accounts for competing risks for death. Design: 2 observational cohort studies, using data from 4946 participants in the Cardiovascular Health Study (CHS) and 4303 participants in the Rotterdam Study (RS). Setting: Community settings in the United States (CHS) and Rotterdam, the Netherlands (RS). Participants: Persons aged 65 years or older who were free of cardiovascular disease. Measurements: A composite of nonfatal myocardial infarction and coronary death. Results: During a median follow-up of 16.5 and 14.9 years, 1166 CHS and 698 RS participants had CHD events, respectively. Deaths from noncoronary causes largely exceeded the number of CHD events, complicating accurate CHD risk predictions. The prediction model had moderate ability to discriminate between events and nonevents (c-statistic, 0.63 in both U.S. and European men and 0.67 and 0.68 in U.S. and European women). The model was well-calibrated; predicted risks were in good agreement with observed risks. Compared with the Framingham point scores, the prediction model classified elderly U.S. persons into higher risk categories but elderly European persons into lower risk categories. Differences in classification accuracy were not consistent and depended on cohort and sex. Adding newer cardiovascular risk markers to the model did not substantially improve performance. Limitation: The model may be less applicable in nonwhite populations, and the comparison Framingham model was not designed for adults older than 79 years. Conclusion: A CHD risk prediction model that accounts for deaths from noncoronary causes among older adults provided wellcalibrated risk estimates but was not substantially more accurate than Framingham point scores. Moreover, adding newer risk markers did not improve accuracy. These findings emphasize the difficulties of predicting CHD risk in elderly persons and the need to improve these predictions.