China-PAR脑卒中模型在北方农村人群中预测脑卒中发病风险的应用

Application of the China-PAR stroke risk equations in a rural northern Chinese population

目的:在中国北方农村人群的前瞻性队列中,独立验证并比较脑卒中5年发病风险预测模型的准确性,对模型在一级预防中的实际应用进行评价。方法:研究对象为2010年6月至8月参加基线调查并随访至2017年1月的6483例基线调查时未患心血管病的40~79岁北京房山农村人群,采用最新发表的中国动脉粥样硬化性心血管疾病风险预测研究(prediction for atherosclerotic cardiovascular disease risk in China,China-PAR)脑卒中模型和美国弗明汉脑卒中风险评分(Framingham stroke risk profile,FSRP)模型,分别计算预测的脑卒中5年发病风险。通过Kaplan-Meier方法调整获得5年实际观察到的新发脑卒中事件的发生率,并计算预测风险与实际发生率的比值,以评价验证队列中是否存在风险的高估或低估。采用区分度C统计量、校准度卡方值,以及校准图评估模型的预测准确性。结果:在本验证队列6483例研究对象平均(5.83±1.14)年的随访时间内,共出现新发脑卒中事件438例。再校准后的China-PAR脑卒中模型和FSRP模型在男性中预测准确性较好,区分度C统计量及其95%可信区间分别为0.709(0.675~0.743)和0.721(0.688~0.754),校准度卡方值分别为5.7(P=0.770)和13.6(P=0.137),但在女性中高估了脑卒中的5年发病风险,再校准后的China-PAR和FSRP模型分别高估了11.6%和30.0%;China-PAR和FSRP模型的区分度接近,C统计量及其95%可信区间在女性中分别为0.713(0.684~0.743)和0.710(0.679~0.740),校准度卡方值分别为12.5(P=0.188)和24.0(P=0.004)。另外,只有China-PAR脑卒中模型的校准图显示其预测风险与实际发生率的一致性较好,特别是在男性人群。结论:China-PAR脑卒中模型对于中国北方农村人群脑卒中5年发病风险的预测优于FSRP模型,特别是在男性中更准确。

Objective:To validate five-year risk prediction models for stroke in a contemporary rural Northern Chinese population.Methods:Totally 6483 rural adults aged 40 to 79 years without cardiovascular diseases were enrolled at baseline between June and August 2010,and followed up through January 2017.Expected prediction risk using the China-PAR(prediction for atherosclerotic cardiovascular disease risk in China)stroke risk equations were compared with the new Framingham stroke risk profile(FSRP).The recalibrated models were applied by adjusting the five-year baseline survival rate and the mean score to our rural northern Chinese population,while keeping other coefficient parameters the same as the original models.Kaplan-Meier analysis was used to obtain the observed event(nonfatal or fatal stroke)rate for the five years,and the expected-observed ratios were calculated to evaluate overestimation or underestimation in the cohort.The models were assessed by discrimination C statistic,calibrationχ2,and calibration charts and plots for illustration as well.Results:Over an average of(5.83±1.14)years of the follow-up in this validation cohort with 6483 rural Chinese participants,438 subjects deve-loped a first stroke event.Recalibrated China-PAR stroke risk equations and FSRP well-performed for predicting five-year stroke risk in men,and had C statistics of 0.709(95%CI,0.675-0.743)and 0.721(95%CI,0.688-0.754),with calibrationχ2 values being 5.7(P=0.770)and 13.6(P=0.137),respectively.However,both China-PAR and FSRP overestimated stroke events by 11.6%and 30.0%in women,and had C statistics of 0.713(95%CI,0.684-0.743)and 0.710(95%CI,0.679-0.740),respectively.Calibrationχ2 values in women were 12.5(P=0.188)for China-PAR and 24.0(P=0.004)for FSRP.In addition,the calibration charts and plots illustrated good agreement between the observations and the predictions only in the China-PAR stroke risk equations,especially for men.Conclusion:In this validation cohort of rural northern Chinese adults,the China-PAR models had better performance of five-year stroke risk prediction than the FSRP,indicating that recalibrated China-PAR stroke risk equations might be appropriate tools for risk assessment and primary prevention of stroke in China.