Jacqmin-Gadda Hélène, Blanche Paul, Chary Emilie, Loubère Lucie, Amieva Hélène, Dartigues Jean-François
Am J Epidemiol. 2014 Oct 15;180(8):790-8. doi: 10.1093/aje/kwu202. Epub 2014 Sep 4.
Early detection of subjects at high risk of developing dementia is essential. By dealing with censoring and competing risk of death, we developed a score for predicting 10-year dementia risk by combining cognitive tests, and we assessed whether inclusion of cognitive change over the previous year increased its discrimination. Data came from the French prospective cohort study Personnes Agées QUID (PAQUID) and included 3,777 subjects aged 65 years or older (1988-1998). The combined prediction score was estimated by means of an illness-death model handling interval censoring and competing risk of death. Its predictive ability was measured using the receiver operating characteristic (ROC) curve, with 2 different definitions depending on the way subjects who died without a dementia diagnosis were considered. To account for right-censoring and interval censoring, we estimated the ROC curves by means of a weighting approach and a model-based imputation estimator. The combined score exhibited an area under the ROC curve (AUROC) of 0.81 for discriminating future demented subjects from subjects alive and nondemented 10 years later and an AUROC of 0.75 for discriminating future demented subjects from all other subjects (including deceased persons). Adjustment for cognitive change over the previous year did not improve prediction.
早期发现有患痴呆症高风险的受试者至关重要。通过处理删失数据和死亡的竞争风险，我们结合认知测试开发了一个用于预测10年痴呆症风险的评分，并评估纳入前一年的认知变化是否会提高其辨别力。数据来自法国前瞻性队列研究“老年人群情况调查”（PAQUID），包括3777名65岁及以上的受试者（1988 - 1998年）。综合预测评分通过处理区间删失数据和死亡竞争风险的疾病 - 死亡模型进行估计。其预测能力使用受试者工作特征（ROC）曲线进行测量，根据对未被诊断为痴呆症而死亡的受试者的不同考虑方式有两种不同定义。为了考虑右删失和区间删失，我们通过加权方法和基于模型的插补估计器来估计ROC曲线。该综合评分在区分未来痴呆症患者与10年后存活且未患痴呆症的受试者时，ROC曲线下面积（AUROC）为0.81，在区分未来痴呆症患者与所有其他受试者（包括已死亡者）时，AUROC为0.75。对前一年认知变化的调整并未改善预测效果。
