OBJECTIVE: To determine the accuracy of self-reported length of coma (LOC) and post-traumatic amnesia (PTA) in persons with medically verified TBI and to investigate factors that affect self-report of LOC and PTA.
DESIGN: Prospective cohort. SETTING: Specialized rehabilitation center with inpatient and outpatient programs. PARTICIPANTS: 242 persons with medically verified TBI who were identified from a registry of persons who had previously participated in TBI related research. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Self-reported LOC, self-reported PTA.
RESULTS: Review of medical records revealed that the mean (SD) medically documented days of LOC and PTA were 6.9 (12) and 19.2 (22), respectively, while self-reported mean (SD) days of LOC and PTA were 16.7 (22) and 106 (194). The average self-report-medical record discrepancy for LOC was 8.2 (21) days and for PTA the average discrepancy was 64 (176) days. Multivariable regression models revealed that time since injury, performance on cognitive tests, and medical record values were associated with self-reported values for both LOC and PTA.
CONCLUSIONS: In this investigation, persons with medically verified TBI showed poor accuracy in their self-report of LOC and PTA. Discrepancies were large enough to affect injury severity classification. Caution should be exercised when considering self-report of LOC and PTA duration.