Elsevier

American Heart Journal

Volume 153, Issue 5, May 2007, Pages 722-731.e8
American Heart Journal

Curriculum in Cardiology
Prediction of first coronary events with the Framingham score: A systematic review

https://doi.org/10.1016/j.ahj.2007.02.027Get rights and content

Background

Uncertainty exists about the performance of the Framingham risk score when applied in different populations.

Objective

We assessed calibration of the Framingham risk score (ie, relationship between predicted and observed coronary event rates) in US and non-US populations free of cardiovascular disease.

Methods

We reviewed studies that evaluated the performance of the Framingham risk score to predict first coronary events in a validation cohort, as identified by Medline, EMBASE, BIOSIS, and Cochrane library searches (through August 2005). Two reviewers independently assessed 1496 studies for eligibility, extracted data, and performed quality assessment using predefined forms.

Results

We included 25 validation cohorts of different population groups (n = 128 000) in our main analysis. Calibration varied over a wide range from under- to overprediction of absolute risk by factors of 0.57 to 2.7. Risk prediction for 7 cohorts (n = 18 658) from the United States, Australia, and New Zealand was well calibrated (corresponding figures: 0.87-1.08; for the 5 biggest cohorts). The estimated population risks for first coronary events were strongly associated (goodness of fit: R2 = 0.84) and in good agreement with observed risks (coefficient for predicted risk: β = 0.84; 95% CI 0.41-1.26). In 18 European cohorts (n = 109 499), the corresponding figures indicated close association (R2 = 0.72) but substantial overprediction (β = 0.58, 95% CI 0.39-0.77). The risk score was well calibrated on the intercept for both population clusters.

Conclusion

The Framingham score is well calibrated to predict first coronary events in populations from the United States, Australia, and New Zealand. Overestimation of absolute risk in European cohorts requires recalibration procedures.

Section snippets

Data sources

We systematically searched for studies of prediction rules for cardiovascular risk using electronic databases (Medline, EMBASE, BIOSIS, Cochrane library; from 1966 to August 2005; no language restriction). Validation studies of prediction rules are difficult to retrieve in electronic data bases because such studies are not indexed in a standardized manner. Thus, we used a sensitive search strategy not specific for the Framingham model but for cardiovascular prediction rules in general (see

Description of validation studies

Our searches retrieved 1496 potentially relevant studies (Figure 1). Seventeen validation studies of the Framingham risk score4, 5, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 with 25 independent prospective validation cohorts met the inclusion criteria (for excluded studies, see Appendix Table IV). Agreement between reviewers was high (chance adjusted κ statistics: 0.89).

Seventeen cohorts provided data for hard CHD or total CHD. One cohort reported CVD outcomes, of which 71% were

Discussion

The Framingham risk score is well calibrated to predict absolute risk for first coronary events in populations from the United States, Australia, and New Zealand. Mean predicted and observed population risk estimates are closely associated and show a high agreement. In European populations, overall agreement of predicted and observed absolute risk is poor due to substantial overestimation.

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    The study was supported by the Helmut Horten Foundation. The funding source had no influence on study design; in the collection, analysis, and interpretation of the data; in the writing of the manuscript; and in the decision to submit the manuscript for publication.

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