Copyright
©The Author(s) 2021.
World J Clin Cases. Mar 26, 2021; 9(9): 2090-2099
Published online Mar 26, 2021. doi: 10.12998/wjcc.v9.i9.2090
Published online Mar 26, 2021. doi: 10.12998/wjcc.v9.i9.2090
Table 3 Oxford Centre for Evidence-Based Medicine levels of evidence
| Level | Therapy/prevention, etiology/harm |
| 1a | Systematic review of RCTs |
| 1b | RCT |
| 1c | “All-or-none” |
| 2a | Systematic review of cohort studies |
| 2b | Cohort study or poor RCT |
| 2c | “Outcomes” research; ecological studies |
| 3a | Systematic review of case-control studies |
| 3b | Individual case-control study |
| 4 | Case series |
| 5 | Expert opinion without critical appraisal, or based on physiology, bench research or “first principles” |
- Citation: Liu YM, Feng Y, Liu YQ, Lv Y, Xiong YC, Ma K, Zhang XW, Liu JF, Jin Y, Bao HG, Yan M, Song T, Liu Q. Chinese Association for the Study of Pain: Expert consensus on chronic postsurgical pain. World J Clin Cases 2021; 9(9): 2090-2099
- URL: https://www.wjgnet.com/2307-8960/full/v9/i9/2090.htm
- DOI: https://dx.doi.org/10.12998/wjcc.v9.i9.2090