Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Proportion of people with PTSD
RCT	24 people with acute stress disorder two weeks after a road traffic accident (RTA) or industrial accident	Proportion of people who fulfilled diagnostic criteria for PTSD immediately after treatment 8% with five sessions of CBT 83% with five sessions of supportive counselling Absolute numbers not reported	P <0.001	Effect size not calculated	CBT
RCT	24 people with acute stress disorder two weeks after RTA or industrial accident	Proportion of people who fulfilled diagnostic criteria for PTSD 6 months 17% with five sessions of CBT 67% with five sessions of supportive counselling Absolute numbers not reported	P <0.05	Effect size not calculated	CBT
RCT 3-armed trial	45 people with acute stress disorder two weeks after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) immediately after treatment 2/14 (14%) with prolonged exposure (five 90-minute sessions) 9/16 (56%) with supportive counselling	P <0.05	Effect size not calculated	CBT
RCT 3-armed trial	45 people with acute stress disorder two weeks after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) immediately after treatment 3/15 (20%) with prolonged exposure (five 90-minute sessions) plus anxiety management 9/16 (56%) with supportive counselling	P <0.05	Effect size not calculated	CBT
RCT 3-armed trial	45 people with acute stress disorder two weeks after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) 6 months 2/13 (15%) with prolonged exposure (five 90-minute sessions) 10/15 (67%) with supportive counselling	P <0.05	Effect size not calculated	CBT
RCT 3-armed trial	45 people with acute stress disorder two weeks after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) 6 months 3/13 (23%) with prolonged exposure (five 90-minute sessions) plus anxiety management 10/15 (67%) with supportive counselling	P <0.05	Effect size not calculated	CBT
RCT 3-armed trial	87 people with acute stress disorder after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) immediately after completion of treatment 36% with CBT (five 90-minute sessions) 50% with supportive counselling Absolute numbers not reported	Reported as not significant (reduction in numeric scores was greater in the CBT group) P value not reported		Not significant
RCT 3-armed trial	87 people with acute stress disorder after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) immediately after completion of treatment 30% with CBT (five 90-minute sessions) plus hypnosis 50% with supportive counselling Absolute numbers not reported	Reported as not significant (reduction in numeric scores was greater in the CBT plus hypnosis group) P value not reported		Not significant
RCT 3-armed trial	87 people with acute stress disorder after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) 6 months 42% with CBT (five 90-minute sessions) 58% with supportive counselling Absolute numbers not reported	Reported as not significant (reduction in numeric scores was greater in the CBT group) P value not reported		Not significant
RCT 3-armed trial	87 people with acute stress disorder after an RTA or non-sexual assault	Proportion of people with PTSD (measured by Clinician Administered PTSD Scale) 6 months 40% with CBT (five 90-minute sessions) plus hypnosis 58% with supportive counselling Absolute numbers not reported	Reported as not significant (reduction in numeric scores was greater in the CBT plus hypnosis group) P value not reported		Not significant