The Promotoer, a brain-computer interface-assisted intervention to promote upper limb functional motor recovery after stroke: a statistical analysis plan for a randomized controlled trial

Abstract

Abstract Background Electroencephalography (EEG)-based Brain-Computer Interfaces (BCIs) allow to modulate the sensorimotor rhythms and are potential technologies for promoting post-stroke motor function recovery. The Promotoer study is planned to assess short and long-term efficacy of the Promotoer system, an EEG-based BCI to assist motor imagery (MI) practice, in enhancing post-stroke functional hand motor recovery. This paper details the statistical analysis plan of the Promotoer study.Methods The Promotoer study is a randomized, controlled, assessors blinded, single-centre, superiority trial, with 2 parallel groups and 1:1 allocation ratio. Subacute stroke patients are randomized to EEG-based BCI-assisted MI training or to MI training alone (ie., no BCI). Internal pilot study for sample size re-assessment is planned. Primary outcome is the effectiveness of the Upper extremity-Fugl-Meyer Assessment (UE-FMA) score. Secondary outcomes include clinical, functional and user experience scores assessed at the end of intervention and at follow-up. Neurophysiological assessments are also planned. Effectiveness formulas have been specified, and intention-to-treat and per-protocol populations have been defined. Statistical methods for comparisons of groups and for development of predictive score of important improvement are described. Explorative subgroup analyses and methodology to handle missing data are considered.Discussion The Promotoer study will produce robust evidence for short/long-term efficacy of the Promotoer system in subacute stroke patients undergoing rehabilitation. Moreover, the development of predictive score of response will allow the transfer of the Promotoer system to optimal clinical practice. The statistical analysis plan, by fully describing statistical principles and procedures for the analysis of data, provides transparency on the analysis of data.Trial registration: ClinicalTrials.gov NCT04353297. Registered on April 15, 2020, https://clinicaltrials.gov/study/NCT04353297