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Table 1 Calculated sample size requirements

From: Critical appraisal of arguments for the delayed-start design proposed as alternative to the parallel-group randomized clinical trial design in the field of rare disease

Parameters Double-blinda Open-label extensionb
A1P mean (SE) −1.45 (0.23) −1.45 (0.23)
Placebo mean (SE) −2.19 (0.25) −1.74 (0.25)
Difference 0.74 0.29
Common SD 2.25 2.25
Effect size 0.32 0.13
N per group 147 946
  1. SE standard error, SD standard deviation, N number of patients
  2. aAnnual rate of lung density change from baseline to 24 months (A1PI versus placebo)
  3. bAnnual rate of lung density change from baseline to 24 months (A1PI versus delayed-start A1PI)