The Relationship of Cognitive Functioning on Social Participation in Individuals Living with Chronic TBI: A Cross-lagged Panel Structural Equation Model Analysis

Research Objectives: To examine the causal influence between cognition function and social participation in individuals with moderate to severe traumatic brain injury (TBI) over the first two years following injury.

Design: Longitudinal design with data collected at acute rehabilitation hospitalization and by telephone interview at years 1 and 2 post injury, fit to a cross lagged panel structural equation model.

Setting: Single TBI Model Systems (TBIMS) site.

Participants: 1465 community dwelling adults with moderate to severe TBI enrolled in at a single TBIMS site.

Interventions: Not applicable.

Main Outcome Measures: The Social Participation (PARTSoc) subscale of the Participation Assessment with Recombined Tools Objective (PART-O), Cognitive subscale of the Function Independence Measure (FIMCog), administered by phone at years 1 and 2 post injury.

Results: A Cross Lagged Panel structural equation model was constructed, including all possible autoregressive and cross-lagged regression paths. Covariances among the two constructs with each time-point were estimated with an equality constraint, in-order to avoid over-specifying the model. Model fit was good according to Comparative Fit Index (CFI) = 0.962 and Standardized Root Mean Square Residual (SRMR) = 0.078. Examination of path estimates revealed that all autoregressive and cross-lagged paths were significant, but the path from FIMCog Y1 on PARTSoc Y2 was stronger (Std 𝛽 = 0.149, p< 0.001) than the path from PARTSoc Y1 on FIMCog Y2 (Std 𝛽 = 0.059, p< 0.025).

Conclusions: While cross-lagged panel models help strengthen causal inference by establish temporality and controlling for stability, they cannot establish causation with certainty. With this caveat in mind, our findings suggest that cognitive function has a stronger effect on later social participation over the first two years post-injury, as compared to the reverse pattern. Cognitive deficits may be an interfering factor that impacts socialization. More research is needed to establish any potential benefit of rehabilitation interventions to address cognitive difficulties that impact socialization.

Author(s) Disclosures: none.