Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Proportion of people with PTSD
Systematic review	716 people 14 RCTs in this analysis	Proportion of people meeting diagnostic criteria for PTSD 186/435 (43%) with trauma-focused CBT 249/281 (89%) with waiting list control and usual care	RR 0.47 95% CI 0.37 to 0.59	Moderate effect size	trauma-focused CBT
RCT	28 people with PTSD related to discrete traumatic events in adulthood	Proportion of people no longer meeting diagnostic criteria for PTSD end of treatment 10/14 (71%) with CBT (up to 12 sessions of cognitive therapy) 0/14 (0%) with no treatment	P <0.005 The RCT reported a significant difference in baseline Clinician Administered PTSD scale scores between the two groups (reported as significant; P value not reported)	Effect size not calculated	CBT