Chamnan Parinya, Simmons Rebecca K, Sharp Stephen J, Khaw Kay-Tee, Wareham Nicholas J, Griffin Simon J
MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.
Cardio-Metabolic Research Group, Department of Social Medicine, Sanpasitthiprasong Hospital, Ubon Ratchathani, Thailand.
PLoS One. 2016 Feb 19;11(2):e0147417. doi: 10.1371/journal.pone.0147417. eCollection 2016.
Framingham risk equations are widely used to predict cardiovascular disease based on health information from a single time point. Little is known regarding use of information from repeat risk assessments and temporal change in estimated cardiovascular risk for prediction of future cardiovascular events. This study was aimed to compare the discrimination and risk reclassification of approaches using estimated cardiovascular risk at single and repeat risk assessments.
Using data on 12,197 individuals enrolled in EPIC-Norfolk cohort, with 12 years of follow-up, we examined rates of cardiovascular events by levels of estimated absolute risk (Framingham risk score) at the first and second health examination four years later. We calculated the area under the receiver operating characteristic curve (aROC) and risk reclassification, comparing approaches using information from single and repeat risk assessments (i.e., estimated risk at different time points).
The mean Framingham risk score increased from 15.5% to 17.5% over a mean of 3.7 years from the first to second health examination. Individuals with high estimated risk (≥20%) at both health examinations had considerably higher rates of cardiovascular events than those who remained in the lowest risk category (<10%) in both health examinations (34.0 [95%CI 31.7-36.6] and 2.7 [2.2-3.3] per 1,000 person-years respectively). Using information from the most up-to-date risk assessment resulted in a small non-significant change in risk classification over the previous risk assessment (net reclassification improvement of -4.8%, p>0.05). Using information from both risk assessments slightly improved discrimination compared to information from a single risk assessment (aROC 0.76 and 0.75 respectively, p<0.001).
Using information from repeat risk assessments over a period of four years modestly improved prediction, compared to using data from a single risk assessment. However, this approach did not improve risk classification.
弗雷明汉风险方程广泛用于基于单个时间点的健康信息预测心血管疾病。关于重复风险评估信息的使用以及估计心血管风险的时间变化对未来心血管事件预测的了解甚少。本研究旨在比较在单次和重复风险评估中使用估计心血管风险的方法的辨别力和风险重新分类情况。
利用参与EPIC - 诺福克队列研究的12197名个体的数据，进行了12年的随访，我们在首次健康检查以及四年后的第二次健康检查时，按估计绝对风险水平（弗雷明汉风险评分）检查了心血管事件发生率。我们计算了受试者工作特征曲线下面积（aROC）和风险重新分类，比较了使用单次和重复风险评估信息（即不同时间点的估计风险）的方法。
从首次健康检查到第二次健康检查，平均3.7年期间，弗雷明汉风险评分均值从15.5%升至17.5%。两次健康检查时估计风险均高（≥20%）的个体，其心血管事件发生率比两次健康检查时均处于最低风险类别（<10%）的个体高得多（分别为每1000人年34.0 [95%CI 31.7 - 36.6] 和2.7 [2.2 - 3.3]）。与前一次风险评估相比，使用最新风险评估信息导致风险分类有微小的无显著变化（净重新分类改善为 - 4.8%，p>0.05）。与单次风险评估信息相比，使用两次风险评估信息可使辨别力略有提高（aROC分别为0.76和0.75，p<0.001）。
与使用单次风险评估数据相比，在四年期间使用重复风险评估信息可适度改善预测。然而，这种方法并未改善风险分类。
