Table 1 Level of evidence (with permission from the SIGN, from section 6 of the SIGN50, 2004) [15, 16]
From: Effects of Tai Chi exercises on self-efficacy and psychological health
| Level of evidence | |
|---|---|
| A | At least one meta-analysis, systematic review, or RCT rated as 1++, and directly applicable to the target population; or |
| A systematic review of RCTs or a body of evidence consisting, principally, of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results | |
| B | A body of evidence including studies rated 2++, directly applicable to the target population and demonstrating overall consistency of results; or |
| Extrapolated evidence from studies rated as 1++ or 1+ | |
| C | A body of evidence including studies rated 2+, directly applicable to the target population and demonstrating overall consistency of results; or |
| Extrapolated evidence from studies rated as 2++ | |
| D | Evidence level 3 or 4; or |
| Extrapolated evidence from studies rated as 2+ | |