MCI sample size estimates for structural measures and a clinical measure – without enrichment, and with respect to five enrichment strategies.

The 95% confidence intervals of the estimated sample sizes are shown in brackets. Sample size estimates are those required to detect 25% slowing in the rate of change in MCI (under various enrichment strategies) that is in excess of that seen in Aβ-negative (Aβ−) HCs (N = 58). P-values for selected pair-wise comparisons are in Tables 4 and 5.Key: All = all MCI participants (no enrichment); Aβ+ = MCI participants who are Aβ-positive at baseline; Aβ+Ptau+ = MCI participants who are both Aβ- and Ptau-positive at baseline; MRI+ = MCI participants who have AD-like atrophy at baseline; MRI+Aβ+ = MCI participants who are Aβ-positive and have AD-like atrophy at baseline; MRI+Aβ+Ptau+ = MCI participants who are simultaneously positive for all three biomarkers; Hipp = Hippocampus; Parahipp = Parahippocampus; cing = cingulate; CDR = clinical dementia rating – sum of boxes score. See text for definition of positive biomarker status classification.

估算样本量的95%置信区间以方括号标注。本次样本量估算旨在检出轻度认知障碍（Mild Cognitive Impairment, MCI）的变化速率减缓幅度，较β淀粉样蛋白阴性（Aβ−）健康对照（Healthy Controls, HCs，N=58）中观测到的水平高出25%，该估算基于多种富集策略开展。经筛选的两两比较P值详见表4与表5。

术语释义：
All：所有MCI受试者（未进行富集）；
Aβ+：基线β淀粉样蛋白（Aβ）阳性的MCI受试者；
Aβ+Ptau+：基线同时为Aβ与磷酸化tau蛋白（Ptau）阳性的MCI受试者；
MRI+：基线存在阿尔茨海默病（Alzheimer's Disease, AD）样脑萎缩的MCI受试者；
MRI+Aβ+：基线Aβ阳性且存在AD样脑萎缩的MCI受试者；
MRI+Aβ+Ptau+：基线三项生物标志物均为阳性的MCI受试者；
Hipp：海马体（Hippocampus）；
Parahipp：海马旁回（Parahippocampus）；
cing：扣带回（cingulate）；
CDR：临床痴呆评定量表（Clinical Dementia Rating, CDR）- 盒评分总和。

生物标志物阳性状态的分类定义详见正文。