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Table 1 Summary statistics and power from Schneider and colleagues with absolute effect size (column J), percentage placebo effect (column K) and sensitivity (column L) in additional columns

From: Requiring an amyloid-β1-42 biomarker may improve the efficiency of a study, and simulations may help in planning studies

A B C D E F G H I J K L
n per group Dropout (%) Effect size (J/H = K × L) Selection method TRT mean PBO mean TRT SD PBO SD Power,
mixed model
Absolute treatment effect (F - E) Percentage placebo effect (J/F) Sensitivity (signal to noise ratio) (F/H)
100 20 0.35 aMCI 0.88 2.86 5.92 5.62 0.56 1.98 0.69 0.51
100 20 0.35 Ab 1.66 3.71 6.18 5.85 0.58 2.05 0.55 0.63
100 20 0.35 t-tau/Ab 1.58 3.66 6.27 5.92 0.57 2.08 0.57 0.62
100 20 0.45 aMCI 0.33 2.85 6.03 5.61 0.71 2.52 0.88 0.51
100 20 0.45 Ab 1.04 3.73 6.25 5.88 0.76 2.69 0.72 0.63
100 20 0.45 t-tau/Ab 0.99 3.65 6.41 5.94 0.73 2.66 0.73 0.61
200 20 0.25 aMCI 0.85 2.84 5.93 5.62 0.54 1.99 0.70 0.51
200 20 0.25 Ab 1.66 3.72 6.22 5.88 0.56 2.06 0.55 0.63
200 20 0.25 t-tau/Ab 1.55 3.67 6.27 5.96 0.61 2.12 0.58 0.62
200 20 0.35 aMCI 0.32 2.85 6.08 5.65 0.78 2.53 0.89 0.50
200 20 0.35 Ab 1.05 3.71 6.28 5.86 0.83 2.66 0.72 0.63
200 20 0.35 t-tau/Ab 0.96 3.64 6.4 5.95 0.85 2.68 0.74 0.61
200 40 0.35 aMCI 0.89 2.85 5.97 5.65 0.7 1.96 0.69 0.50
200 40 0.35 Ab 1.65 3.68 6.18 5.86 0.71 2.03 0.55 0.63
200 40 0.35 t-tau/Ab 1.57 3.65 6.3 5.95 0.73 2.08 0.57 0.61
200 40 0.45 aMCI 0.32 2.87 6.1 5.65 0.86 2.55 0.89 0.51
200 40 0.45 Ab 1.06 3.7 6.34 5.87 0.88 2.64 0.71 0.63
200 40 0.45 t-tau/Ab 0.93 3.68 6.36 5.99 0.9 2.75 0.75 0.61
400 20 0.25 aMCI 1.45 2.86 5.92 5.63 0.81 1.41 0.49 0.51
400 20 0.25 Ab 2.23 3.7 6.15 5.88 0.84 1.47 0.40 0.63
400 20 0.25 t-tau/Ab 2.17 3.68 6.23 5.98 0.87 1.51 0.41 0.62
400 40 0.25 aMCI 0.86 2.85 6 5.66 0.71 1.99 0.70 0.50
400 40 0.25 Ab 1.67 3.7 6.27 5.89 0.77 2.03 0.55 0.63
400 40 0.25 t-tau/Ab 1.54 3.68 6.32 6 0.76 2.14 0.58 0.61
400 40 0.35 aMCI 1.46 2.86 5.92 5.63 0.93 1.4 0.49 0.51
400 40 0.35 Ab 2.25 3.73 6.14 5.88 0.94 1.48 0.40 0.63
400 40 0.35 t-tau/Ab 2.16 3.67 6.23 6 0.95 1.51 0.41 0.61
  1. Adapted with permission from Table 2 of Schneider and colleagues [1]. TRT, treatment; PBO, placebo; SD, standard deviation; aMCI, amnestic mild cognitive impairment; Ab, requires low Ab1-42 biomarker for enrollment; t-tau, requires high total tau to Ab1-42 ratio for enrollment.