Outcome after traumatic brain injury: pathway analysis of contributions from premorbid, injury severity, and recovery...

To examine the relationship of premorbid variables, injury severity, and cognitive and functional status to outcome 1 year after traumatic brain injury (TBI) and to assess the feasibility of multivariate path analysis as a way to discover those relationships.

Prospective, longitudinal.

Level I trauma center, acute inpatient rehabilitation hospital.

One hundred seven subjects (87 men, 20 women; mean age, 33.91 +/- 14.2 yr) who had experienced severe TBI, typically from motor vehicle crashes.

Acute medical and rehabilitation care.

Disability Rating Scale, Community Integration Questionnaire, and return to employment. Evaluated in acute rehabilitation, and at 6 and 12 months' postinjury.

Path analyses revealed that premorbid factors had significant relationships with injury severity, functional skills, cognitive status, and outcome; injury severity affected cognitive and functional skills; and cognitive status influenced outcome. No significant relationships were found between injury severity and emotional status, injury severity and outcome, emotional status and outcome, and functional skills and outcome.

Multivariate analysis is important to understanding outcome after TBI. Injury severity, as measured in this study, is less important to 12-month outcome than the premorbid status of the person and the difficulties (particularly cognitive deficits) exhibited at follow-up 6 months after the trauma.