| 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 |
[13] Opiates (caution): Müller GJ, Modler H, Wium CA, Veale DJH, Marks CJ. Scorpion sting in southern Africa: diagnosis and management. CME Oct 2012; 30(10):356-61. http://www.cmej.org.za/index.php/cmej/article/view/2545/2580