Subjective cognitive functioning in adults hospitalized after traumatic brain injury: A four-year follow-up.

Objective: To document the evolution of subjective cognitive functioning over four years in adults hospitalized after traumatic brain injury (TBI), comparing mild and moderate-severe TBI, and accounting for sociodemographic and clinical factors.

Method: This secondary analysis of a longitudinal observational cohort study includes 222 adult participants hospitalized following a TBI (mean age = 41 ± 15 years; 29% women; 65% mild, 35% moderate-severe TBI). Data were collected via in-person/telephone interview and self-report questionnaires administered 4, 8, 12, 24, 36, and 48 months post-TBI. The primary outcome measure for subjective cognitive functioning was the Medical Outcomes Study Cognitive Functioning Scale (MOS-COG).

Results: Mixed model analyses revealed a significant Time effect, with post hoc tests showing a better perceived cognitive functioning on the MOS-COG at 4 months than at 24 and 36 months after TBI. The TBI severity effect and TBI severity*Time interaction were not significant. Secondary effects revealed that poorer subjective cognitive functioning was associated with higher levels of symptoms of depression, anxiety, insomnia, and fatigue, and lower quality of life. Overall, the MOS-Cog score was about one standard deviation below the normative mean, suggesting greater cognitive complaints than in the general population, regardless of injury severity.

Conclusions: The results suggest that subjective cognitive functioning is poorer than normative values and fairly stable over four years after TBI, with a slight decrease between 4 and 24-36 months, and is similar between mild and moderate-severe TBI.