What the study found
The study found substantial variation in how ALS clinical trials analyzed the ALSFRS-R, the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, a disability rating scale. The choice of statistical method could change the estimated treatment effect and the reliability of trial conclusions.
Why the authors say this matters
The authors conclude that inconsistent analysis methods can make ALS trial results harder to interpret and compare. They say this may affect clinical decision-making and drug development, and suggest that statistical consensus recommendations could improve the usefulness of disability scales in trials.
What the researchers tested
The researchers systematically identified randomized, placebo-controlled ALS clinical trials that used the ALSFRS-R as a primary endpoint, with at least 20 randomly assigned patients and at least 12 weeks of follow-up. They extracted information on statistical analysis methods and missing-data handling, then used simulation based on the Ceftriaxone trial dataset to assess false-positive risk and statistical power.
What worked and what didn't
Across 45 trials with 7,338 patients, the researchers found 39 distinct statistical methods, using both longitudinal and cross-sectional approaches. Most trials, 55.6%, did not use all available longitudinal ALSFRS-R measurements, and 38.9% of the methods were at risk of increasing false-positive rates. Estimated treatment effects ranged from -1.33 to +2.33 standard deviation differences, and statistical power for valid strategies ranged from 17.9% to 78.2%.
What to keep in mind
The analysis was limited to ALS clinical trials using ALSFRS-R as the primary endpoint and meeting the study's eligibility criteria. The abstract does not describe limitations beyond this scope, so no additional caveats are stated in the available summary.
Key points
- The study reviewed 45 randomized ALS clinical trials using the ALSFRS-R as a primary endpoint.
- It identified 39 different statistical methods for analyzing the same kind of disability scale data.
- More than half of the trials did not use all available longitudinal ALSFRS-R measurements.
- Different methods produced treatment effect estimates ranging from -1.33 to +2.33 standard deviation differences.
- Some methods were at risk of increasing false-positive rates, and valid methods showed widely varying statistical power.
Disclosure
- Research title:
- ALSFRS-R trial analysis methods varied widely across ALS studies
- Authors:
- Daphne N. Weemering, Jordi W. J. van Unnik, Angela Genge, Leonard H. van den Berg, Ruben P. A. van Eijk
- Institutions:
- Montreal Neurological Institute and Hospital, University Medical Center Utrecht, University Medical Center Utrecht, University Medical Center Utrecht, University Medical Center Utrecht
- Publication date:
- 2026-04-21
- OpenAlex record:
- View
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