Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Proportion of people who developed PTSD
RCT	151 people who had been involved in a road traffic accident in the past month	Rate of PTSD 6 months with CBT (three to six sessions) plus educational techniques with no psychological intervention Absolute results not reported	P = 0.39 The RCT found that people in the treatment group had a significantly higher baseline risk of PTSD compared with the no-intervention group, which makes the results difficult to interpret		Not significant