Quantifying Placebo Effects in Hereditary Ataxia Trials: A Meta‐Analysis of Scale for the Assessment and Rating of Ataxia ( SARA) Score Changes
Year: 2026
Type: article
Study designs: Systematic Review, Meta-Analysis
Abstract: BACKGROUND AND OBJECTIVES: The Scale for the Assessment and Rating of Ataxia (SARA) is the primary outcome most frequently used in clinical trials involving hereditary ataxia patients. This systematic review and meta-analysis aimed to quantify changes in SARA scores within placebo arms of these trials to better understand the placebo effect. METHODS: Placebo arm data were collected from clinical trials on hereditary ataxias via PubMed and ClinicalTrials.gov. Heterogeneity was assessed with funnel plots. A random-effects meta-analysis was conducted on trials providing variance data. The influence of covariates such as trial duration, continent, intervention type, publication date, and trial result was evaluated. RESULTS: = 94%). Placebo response differed significantly by continent, with European trials showing minimal effect (0.01 [-0.35; 0.37]) and Asian trials the largest effect (-0.85 [-1.13; -0.58]). Intervention type also impacted placebo response, with device interventions exhibiting the strongest effect (-0.84 [-1.60; -0.08]). Trial duration showed no statistically significant effect; however, a trend of decreasing placebo effect over time was observed. DISCUSSION: The analysis indicates a measurable placebo effect on SARA scores. Both intervention type and geographic region significantly influenced the strength of this effect, suggesting roles for patient expectations and cultural factors. Additionally, there was a trend toward reduction of placebo response as trial duration increased. © 2026 International Parkinson and Movement Disorder Society.
Source: Movement Disorders
DOI: 10.1002/mds.70151
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W7126276964