Dropout rate in randomised controlled trials of balance and gait rehabilitation in multiple sclerosis: is it expected to be different for virtual reality-based interventions? A systematic review with meta-analysis and meta-regression. - María Jesús Casuso-Holgado; Cristina García-Muñoz; Rocío Martín-Valero; David Lucena-Anton; José Antonio Moral-Muñoz; María-Dolores Cortés-Vega (Virtual Real., 2023)