Table 4

Sample size estimations for detection of a 50% effect in a hypothetical 18-month placebo-controlled clinical trial

PopulationPrimary endpoint18-month change from baseline (CV, %)Total sample size (per group)% benefit of using the composite clinical motor score
PDMDS-UPDRS part III2.96±10.04 (339.19)1450 (725)64% fewer participants
Composite clinical motor score2.37±4.85 (204.64)528 (264)
iRBDMDS-UPDRS part III3.08±7.74 (251.30)794 (397)51% fewer participants
Composite clinical motor score2.52±4.43 (175.79)392 (196)
  • CV, coefficient of variation in percentage defined as the ratio of SD to the mean (average); iRBD, isolated rapid eye movement sleep behaviour disorder; MDS-UPDRS III, Movement Disorders Society-Unified Parkinson’s Disease Rating Scale III; PD, Parkinson’s disease.