Multifactorial approach to the prevention of coronary heart disease: from computer to paper and pencil?

Prediction of first coronary events with the Framingham score: a systematic review

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 = 18658) 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: beta = 0.84; 95% CI 0.41-1.26). In 18 European cohorts (n = 109499), the corresponding figures indicated close association (R2 = 0.72) but substantial overprediction (beta = 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.

Increased absenteeism from work among aware and treated hypertensive and hypercholesterolaemic patients

AIM

The 'labelling hypothesis' was introduced on the basis of the observation that labelling subjects with blood pressure elevation as hypertensive was associated with an increase in sickness absence. In the Belstress I study this hypothesis was analysed in the same way for the possible influence on sick leave of labelling persons with elevated cholesterol as hypercholesterolaemic.

METHODS AND RESULTS

The Belstress I cohort concerns a sample of more than 16,000 men and 5,000 women at work in 24 Belgian industries in various sectors. Baseline data were collected by questionnaire and clinical examination. Awareness was defined as answering positively to the question 'did a physician ever tell you that your blood pressure/serum cholesterol was too high?' Sick leave data were independently and objectively recorded during 1 year following the screening. Sick leave was treated in a dichotomous way whereby the event was defined as being in the highest quartile of the annual number of days of sick leave (10 days or more for men and 15 days or more for women) or as being in the highest quartile of the annual number of spells of sick leave (two spells or more for both sexes). Gender-specific logistic regression analyses were performed, with adjustment for a large set of covariates. A positive association was observed between both awareness of hypertension and awareness of hypercholesterolaemia and the various definitions of sick leave, in both sexes and after adjustment for different covariates. When dividing up aware subjects into treated versus untreated, we observed in men the highest sick leave incidence in aware and treated hypertensive patients as well as in aware and treated hypercholesterolaemic patients. In women findings were less consistent, probably due to the smaller sample size. When looking at cumulative effects by examining participants with both hypertension and hypercholesterolaemia and their level of awareness for one or both risk factors, a statistically significant gradient was noticed in men, with the highest sick leave incidence, whatever the definition, in men aware for both risk factors, followed by men aware for one. In women the same trends were observed, but no level of statistical significance was reached.

CONCLUSION

Without being able to test the effect of 'labelling' as such, our study provides support for the association between awareness of two different coronary risk factors and incidence of sick leave. Probably a common mechanism is at the base of these findings. Further research is needed, in order to reduce potential negative effects of screening on human wellbeing as well as on productivity.

Risk scoring in the assessment of cardiovascular risk

PURPOSE OF REVIEW

Cardiovascular risk scoring is incorporated in guidelines and recommended for targeting preventive treatment. Evidence is required on the most appropriate method, its accuracy in a given population, and its effectiveness in favourably influencing clinical behaviour and health outcomes.

RECENT FINDINGS

Recent risk scores address inaccuracies that arise when methods are transferred between populations, and specific methods and recalibrations are described for use in low-risk populations. Ethnic and social differences in risk are also recognized in the context of cardiovascular risk scoring. More sensitive measures of known risk factors and numerous emerging risk factors are reported and new statistical methods and sources of data suggested. Little emphasis has been placed on evaluation of the clinical effectiveness of cardiovascular risk scores. Education in cardiovascular risk assessment may help improve uptake of methods by healthcare professionals.

SUMMARY

Numerous risk scoring methods are available to the healthcare professional but use is patchy. Accuracy varies between populations and methods have been developed to compensate for some of this variability. If risk scoring methods are to be widely used in general practice, evidence is required on both the accuracy of methods in appropriate populations and their effectiveness in improving health outcomes.