| 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 |
[28] Lidocaine 1% without adrenaline (epinephrine) - diluent:Kingston M, French P, Higgins S, McQuillanO,Sukthankar A, Stott C, McBrienB, Tipple C, Turner A, Sullivan AK; Members of the Syphilis guidelines revision group 2015, Radcliffe K, Cousins D, FitzGerald M, Fisher M, Grover D, Higgins S, Kingston M, Rayment M, Sullivan A. UK national guidelines on the management of syphilis 2015.Int J STD AIDS. 2016 May;27(6):421-46. https://www.ncbi.nlm.nih.gov/pubmed/26721608