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Table 4 Estimated sample size in heart failure group to detect the change of ECV and λ with a power of 80%

From: Diffuse myocardial fibrosis evaluation using cardiac magnetic resonance T1 mapping: sample size considerations for clinical trials

Clinical change Caset 1 Case 2 Case 3
  SDD1 N1 SDD2 N2 SDD3 N3
λ (0.063) 0.078 26 0.117 56 0.156 98
ECV (0.038) 0.048 27 0.072 58 0.096 102
  1. Sample size need to detect a clinical meaning change of ECV and λ with 80% of power and an alpha error of 0.05. Sample size is derived from the inter-study SDD as described by Altman [33] and Marchin [32]. Note that for studies comparing active vs. placebo, these sample size numbers need to be doubled. Case 1: the inter-study SDD1 in HF group was estimated 2.8 fold greater than the intra-study SDD; Case 2, the inter-study SDD2 was estimated 1.5 times more than SDD1; Case3, the inter-study SDD3 was estimated 2 times more than SDD1.