PCV19: DISCRIMINABILITY FOR RISK OF CARDIOVASCULAR EVENTS

Abstract

Risk equations based on the Framingham Heart Study (FHS) are used in NZ to predict the 5y risk of an incident CV event for individuals without cardiovascular (CV) disease. OBJECTIVES: To establish in a NZ population without overt CV disease: (i) the discriminability of the relevant FHS risk equation for prediction of first hospitalisation or mortality for any cardiovascular event; (ii) whether FHS risk equations have better discriminability than single risk factors. METHODS: Observations were taken from a cohort study with 6354 (4638 M + 1716 F) participants age 32–74 without known CV disease, taken from the workforce of a nation-wide multi-industry corporation plus a random sample of the Auckland electoral rolls. Prognostic factors were assessed in 1992–93 by a questionnaire plus physiological measurements (BP, cholesterol etc.). Outcomes data were CV mortality and hospital discharges from Jan. 1988 to Dec. 1998 (NZ Health Information Service). Risk predictions were compared with outcomes, and receiver-operator characteristics (ROC) curves were constructed. The area under the ROC curve was obtained by fitting a dual-Gaussian unequal variance model. RESULTS: Table 1 shows the area under the ROC curves. CONCLUSIONS: FHS risk equations or age alone provide moderate discriminability for individuals with 5y risk of a CV event that requires hospitalisation. SBP and serum lipids have weaker discriminability. Area under ROC curves (±95% CI). FHS .72 ± .030 .78 ± .055 .74 ± .025 Age .70 ± .029 .77 ± .058 .71 ± .026 SBP .62 ± .034 .69 ± .062 .64 ± .030 Chol/HDLc .61 ± .034 .64 ± .066 .63 ± .030 BMI .56 ± .034 .61 ± .063 .58 ± .029