Predictors of Poststroke Aphasia Recovery: A Systematic Review-Informed Individual Participant Data Meta-Analysis

Background: The factors associated with recovery of language domains affected by stroke remain uncertain. We described recovery of overall-language-ability, auditory comprehension, naming and functional-communication across participants’ age, sex and aphasia chronicity in a large, multilingual, international aphasia dataset. Methods: Individual participant data (IPD) meta-analysis of systematically-sourced aphasia datasets described overall-language-ability using the Western Aphasia Battery Aphasia-Quotient (WAB-AQ); auditory comprehension by Aachen Aphasia Test Token Test (AAT-TT); naming by Boston Naming Test (BNT) and functional-communication by AAT Spontaneous-Speech Communication subscale (AAT-SC). Multivariable analyses regressed absolute score-changes from baseline across language domains onto covariates identified a priori in RCTs and all study types. Change-from-baseline scores were presented as estimates of means and 95% confidence intervals (CI). Heterogeneity was described using relative variance. Risk of bias was considered at dataset and meta-analysis level. Results: Assessments at baseline (median=43.6 weeks post-stroke; interquartile range (IQR) [4-165.1]) and first-follow-up (median=10 weeks from baseline; IQR [3, 26]) were available for n=943 on overall-language-ability, n=1,056 on auditory comprehension, n=791 on naming and n=974 on functional-communication. Younger age