Efficacy of Intervention of Participation and Executive Functions (I-PEX) for Adults Following Traumatic Brain Injury: A Preliminary Pilot Randomized Controlled Trial.

Background: Participation restrictions following traumatic brain injury are associated with executive function (EF) deficits (EFDs). The subacute recovery phase's specific characteristics (enhanced brain plasticity and impaired self-awareness) and contextual factors (inpatient setting) warrant adjusting cognitive rehabilitation protocols. The Intervention of Participation and Executive Functions (I-PEX) was designed to improve EFDs during subacute inpatient rehabilitation.

Objective: To investigate the I-PEX's preliminary efficacy to improve EFDs during the performance of complex daily activities and enhance self-awareness, cognitive self-efficacy, participation, and quality of life postdischarge.

Methods: A pilot pre-, post-, and follow-up double-blind randomized controlled trial with 25 participants randomly allocated to the I-PEX (n = 13) or treatment-as-usual (n = 12) group. Cognitive assessments were administered pre- and postintervention, and quality of life and participation questionnaires 1-month postdischarge. Data analysis included repeated measures analysis of variance mixed design and independent -tests, extracting effect sizes.

Results: Significant group-by-time interaction effect with a medium effect size was found for the primary outcome measure; EFs manifested in complex daily activities, indicating a larger improvement for the experimental group. The group effect was not significant. The experimental group's mean delta score (pre-post improvement) was significantly higher (1.75 ± 2.89;  = 2.52,  = .019), with a large effect size ( = 1.012, 95% confidence interval [0.166-1.840]). We found no significant group and interaction effects for EFs, self-awareness, and cognitive self-efficacy or no significant differences in participation or quality of life postdischarge.

Conclusions: Results provide initial evidence for the I-PEX efficacy in treating EFDs in the subacute phase and could help determine effect size for future studies.

Clinical Trial Registry Number: ClinicalTrial.gov NCT04292925.