Figure 4.

Power simulations for randomised placebo-controlled trial. Illustrating a treatment effect corresponding to a 40% reduction in baseline PR, comparing difference in ALSFRS-R change (red) or plasma NFL (green) between groups using mixed models for repeated measures, demonstrating improved statistical power (1 − β) for a given sample size when using plasma NFL as an outcome measure. Points indicate simulated power at given sample size for 1000 iterations with α = 0.05. ALSFRS-R, revised ALS Functional Rating Scale score; NFL, neurofilament light chain; n, number of participants per group.