Table 3

MS-SMART required sample size/arm by treatment effect size, significance level and statistical power

MRI measurement timesBaseline–96 weeks
Two-sided significance level0.01670.05
Statistical power (%)80908090
Treatment effect:12315892123
  • Treatment effect will be expressed as relative mean difference in PBVC under treatment. PBVC assessed using the SIENA registration-based method.

  • MS-SMART, Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial; PBVC, percentage of brain volume change; SIENA, Structural Image Evaluation, using Normalisation of Atrophy.