| Level I | Good quality evidence |
Systematic review of RCTs with consistent findings High quality individual RCT |
| Level II |
Limited quality patient orientated evidence |
Systematic review of lower quality studies or studies with inconsistent findings Low quality clinical trial Cohort studies Case-control studies |
| Level III | Other |
Consensus guidelines, extrapolations from bench research, usual practice, opinion, disease-oriented evidence (intermediate or physiologic outcomes only), or case series |
[36] Selective serotonin reuptake inhibitors – post-traumatic stress disorder: Mellman TA, Byers PM, Augenstein JS. Pilot evaluation of hypnotic medication during acute traumatic stress response. J Trauma Stress. 1998 Jul;11(3):563-9. https://www.ncbi.nlm.nih.gov/pubmed/9690193
Selective serotonin reuptake inhibitors – post-traumatic stress disorder: Tol WA, Barbui C, van Ommeren M. Management of acute stress, PTSD, and bereavement: WHO recommendations. JAMA. 2013 Aug 7;310(5):477-8. https://www.ncbi.nlm.nih.gov/pubmed/23925613