Comparison of the prediction by 27 different factors of coronary heart disease and death in men and women of the Scottish Heart Health Study: cohort study

Abstract

Objective: To compare prediction by 27 different factors in men and women of coronary heart disease events, coronary deaths, and deaths from all causes.

Design: Cohort study.

Setting: Scottish population study.

Subjects: In 1984-7 random sampling of residents aged 40-59 produced 11,629 men and women who generated survey clinic questionnaires, examination findings, and blood and urine specimens.

Main outcome measures: Subsequent death, coronary artery surgery, and myocardial infarction. Risks were calculated for each category of factor or fifth of continuous variables. 27 factors were ranked by descending age adjusted hazard ratio of the top to bottom class in each factor, by sex and end point.

Results: Follow up averaged 7.6 years, during which the 5754 men had 404 coronary events, 159 coronary deaths, and 383 deaths and the 5875 women 177, 47, and 208 respectively. The rankings for factors for the three end points were mainly similar in men and women, although hazard ratios were often higher in women. Classical risk factors ranked better for predicting coronary risk than newer ones. Yet strong prediction of coronary risk was no guarantee of significant prediction of all cause mortality. Findings included an anomalous coronary protective role for type A behaviour in women; raised plasma fibrinogen as a strong predictor of all end points; and an unexpectedly powerful protective relation of dietary potassium to all cause mortality.

Conclusions: These initial unifactorial rankings and comparisons must be interpreted with caution until potential interaction, confounding, and problems of measurement and causation are further explored.