How accurately do general practitioners and students estimate coronary risk in hypercholesterolaemic patients?

Abstract

Recent guidelines on hyperlipidaemia recommend the calculation of individual coronary risk, at least for patients without previous cardiovascular disease. Although tables and computer programs exist, the estimates are often made on an intuitive basis. The aim of the present work was to study Swedish general practitioners’ (GPs) and medical students’ ability to estimate the 10-year risk of coronary events for hypercholesterolaemic patients. Two hundred randomly selected Swedish GPs and 73 medical students in their final year of medical school were asked to estimate coronary risk for 10 written case descriptions with different cholesterol levels (at least 5.5 mmol/l) and combinations of other risk factors. Both primary and secondary prevention cases were represented. The risk estimates were compared with the estimates from the Framingham equation and a Swedish equation. The interindividual differences in estimated risk were remarkable for both GPs and students. Both GPs and students underestimated coronary risk, especially for high-risk patients. GPs tended to be more accurate than students in ranking the cases. Cases with previous coronary heart disease were not recommended treatment to the extent that the guidelines recommend. Both GPs and students were quite accurate in estimating absolute risk increase attributable to successive cholesterol increases in a scenario with other risk factors kept constant. It was concluded that GPs and medical students need help to differentiate more accurately between patients at high and low coronary risk, and greater effort should be made to communicate the advantages and difficulties involved in multiple risk assessment. The requirements for decision support are discussed. More evidence is needed on the validity of the Framingham equation for new population samples.