| 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 |
[25] Metronidazole, oral: Marie C, Petri WA Jr. Amoebic dysentery. BMJ ClinEvid. 2013 Aug 30;2013. pii:
0918. http://www.ncbi.nlm.nih.gov/pubmed/23991750
Metronidazole, oral: Gonzales ML, Dans LF, Martinez EG. Antiamoebic drugs for treating amoebic colitis. Cochrane Database Syst Rev. 2009 Apr 15;(2):CD006085. http://www.ncbi.nlm.nih.gov/pubmed/19370624