assessed admissions of adults who had been involved in an MVA over a 10-month period. Exclusion criteria for the cohort were inability to speak English, PTA for over 24 hours, not being medically fit or not being on narcotic analgesia other than codeine 4 weeks after trauma, and inability to be contacted. After application of exclusion criteria, 79 (55 male and 24 female) patients with mild TBI and 92 (61 male and 31 female) without mild TBI were evaluated 2–25 days after trauma. An assessment was administered 6 months after injury to 63 (80%) mild-TBI patients and 71 (77%) controls; 37 patients were lost to followup. The presence of ASD was assessed with the Acute Stress Disorder Interview (ASDI), and the presence of PTSD at 6 months was assessed with the PTSD module of the Composite International Diagnostic Interview (CIDI); both were administered by clinical psychologists. Mean injury severity score (ISS) was greater in mild-TBI patients (9.28) than in non–mild-TBI patients (4.0) (p < 0.001). Non-TBI patients reported fear and helplessness more often than mild-TBI patients during the acute and 6-month followup assessments; intrusive memories were also more common during the acute phase in non-TBI patients. There was no significant difference between 11 mild-TBI and 12 non-TBI patients in the rates of diagnosed ASD (14% and 13%, respectively) or between 15 TBI and 18 non-TBI patients in rates of diagnosed PTSD (24% and 25%, respectively).
In a separate analysis of the same MVA population, Bryant and Harvey (1999b) investigated the relationship between PTSD and PCS in a population of mild-TBI patients. Over the period of study, 126 patients were initially identified; at the 6-month followup, 46 (32 male and 14 female) mild-TBI patients (mean ISS, 8.96; SD, 6.08) and 59 (31 male and 28 female) non-TBI patients (mean ISS, 3.92; SD, 3.74) were captured, representing 83% of the original sample. Assessments administered at 6 months were the PTSD module of the CIDI and the Postconcussive Symptom Checklist. Results indicated that 20% (n = 9) of mild-TBI patients and 25% (n = 15) of non-TBI patients met the criteria for PTSD diagnosis. Concentration deficits, dizziness, fatigue, headache, sensitivity to sound, and visual disturbances were reported more often by patients with PTSD than those without it in the mild-TBI sample; concentration deficits and irritability were reported more often in patients with PTSD than those without it in the non-TBI sample. Subjects with PTSD reported more frequent irritability than in those without PTSD in the mild-TBI sample.
With the same population as described above, Bryant and Harvey (1998) and Harvey and Bryant (2000) prospectively studied the frequency of ASD after mild TBI and its utility in predicting PTSD. Of 79 patients who sustained a mild TBI and were administered the ASDI within 1 month after trauma, 11 (14%) met the criteria for ASD. The CIDI module for PTSD was administered at 6 months (n = 63) and 2 years (n = 50) after injury; this represented a 63% retention rate of the original study group. At 6 months and 2 years after trauma, 24% (n = 15) and 22% (n = 11) of patients, respectively, met the criteria for PTSD. Of those with ASD, nine (82%) had a diagnosis of PTSD at 6 months and eight (80%) at the 2-year followup. Of those without ASD, six (12%) and three (8%) had PTSD at 6 months and 2 years, respectively.
A number of studies were based on a series of longitudinal investigations of health outcomes related to TBI conducted at the University of Washington by Dikmen and colleagues. The data from the studies have been formed into a repository and have been used to address questions about outcomes. The studies include Behavioral Outcome of Head Injury, Patient Characteristics and Head Injury Outcome, Dilantin Prophylaxis of Post-Traumatic Seizures, and