Overview of evidence based criteria
| Classes of evidences and strength of recommendations adopted from the guidelines of the American Academy of Neurology.7 |
| Classes of evidence |
| Class I: Evidence provided by one or more well designed randomised controlled clinical studies. |
| Class II: Evidence provided by one or more well designed clinical studies such as prospective open, case–control studies, etc. |
| Class III: Evidence provided by expert opinion, non-randomised historical controls, or case reports of one or more patients. |
| Strength of recommendations |
| Type A: Strong recommendation, based on class I evidence or overwhelming class II evidence when circumstances preclude randomised clinical trials. |
| Type B: Recommendation based on class II evidence. |
| Type C: Recommendation based on strong consensus of class III evidence. |