A Cochrane review included 11 RCTs with a total of 941 participants with post-traumatic stress disorder (PTSD). The trials included motor vehicle accident victims, women who had emergency Caesarean sections and caregivers and parents following the news that their child had cancer. The trials evaluated brief psychological interventions aimed at preventing PTSD in individuals exposed to a specific traumatic event, examining a heterogeneous range of interventions. Regarding the PTSD diagnosis, a primary outcome measure, there was no difference between treatment and control groups at initial outcome (RR 0.84; 95% CI 0.60 to 1.17; 5 trials, n=479). There was no difference between treatment and control conditions at 3-6 month follow-up, either (RR 0.67; 95% CI 0.34 to 1.33; 4 trials, n=312). There was a trend for increased self-report of PTSD symptoms at 3 to 6 month follow-up in those who received an intervention (SMD 0.23; 95% CI 0.00 to 0.46; 4 trials, n=292). Two studies compared a memory structuring intervention against supportive listening; there was no evidence supporting the efficacy of this intervention.
Comment: The quality of evidence is downgraded by study quality (inadequate allocation concealment) and inconsistency (heterogeneity in populations and interventions).