Cross-Validation of a Classification System for Persons With Traumatic Brain Injury in the Posthospital Period.

OBJECTIVE: To (1) identify groupings of persons with traumatic brain injury (TBI) in the posthospital period in a cohort recruited in Australia; (2) compare groupings from the Australian cohort to groupings previously developed for a US cohort.

SETTING: Rehabilitation centers in the US and Australia.

PARTICIPANTS: A total of 170 persons with TBI from Australia and 504 persons with TBI from the United States. Participants were aged 18 to 64 years, greater than 6 months postinjury, had capacity to give consent, and had definitive contemporaneous medical evidence of TBI.

DESIGN: Observational study.

MAIN MEASURES: Cognitive tests-Wechsler Letter-Number Sequencing and Coding, Rey Auditory Verbal Learning Test, Trail Making Test, Verbal Fluency. Questionnaires-9 scales from the Traumatic Brain Injury Quality-of-Life system; Neurobehavioral Symptom Inventory; Economic Quality of Life, Family Assessment Device-General Functioning. Performance validity-Word Memory Test.

RESULTS: Agreement in classification for the 2 samples was only moderate with 63.5% correctly classified and Cohen's κ = 0.53. A post hoc analysis placing all persons showing poor performance validity in the same group improved classification to 73% and Cohen's κ = 0.65 indicating substantial agreement.

CONCLUSION: Results provided support for the patient groups developed for the US sample and indicate that these groupings largely replicated in a new cohort.