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Table 10 Required Sample Size for High-Risk Group Patients with Two Interim Analyses

From: Statistical design of Phase II/III clinical trials for testing therapeutic interventions in COVID-19 patients

Required Sample Size for High-Risk Group Patients with Two Interim Analyses
  Power = 80% Power = 90%
P1 P0 = 80% P0 = 70% P0 = 80% P0 = 70%
70% 476 NA 660 NA
65% 222 2250 308 3122
60% 129 579 179 803
55% 84 262 117 363
50% 59 148 82 206
45% 43 95 60 131
40% 33 65 45 90
35% NA 46 NA 64
  1. P0: 30 days mortality rate in standard arm. P1: 30 days mortality rate in treatment arm
  2. For 80% power: probability of rejection at each look: 1st look p < 0.002, futility look p > 0.835, 2nd look p < 0.015, futility look p > 0.312, final look p < 0.046
  3. For 90% power: probability of rejection at each look: 1st look p < 0.002, futility look p > 0.830, 2nd look p < 0.015, futility look p > 0.297, final look p < 0.046
  4. 1:1 randomization; ρ = 3.0. NA = Not Applicable