| 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 |
[11] Antiviral therapy, oral (recurrent herpes simplex): Le Cleach L, Trinquart L, Do G, Maruani A, Lebrun-Vignes B, Ravaud P, Chosidow O. Oral antiviral therapy for prevention of genital herpes outbreaks in immunocompetent and nonpregnant patients. Cochrane Database Syst Rev. 2014 Aug 3;(8):CD009036. https://www.ncbi.nlm.nih.gov/pubmed/25086573