|
Overview of the GRADE system for grading the quality of evidence: criteria for assigning grade of evidence |
|
| Criteria for assigning level of evidence |
|
|
|
|
| Type of evidence |
|
| Randomized trial |
High |
| Observational study |
Low |
| Any other type of research evidence |
Very low |
| Increase level if: |
|
| Strong association |
(+1) |
| Very strong association |
(+2) |
| Evidence of a dose response gradient |
(+1) |
| Plausible confounders reduced the observed effect |
(+1) |
| Decrease level if: |
|
| Serious or very serious limitations to study quality |
(-1) or (-2) |
| Important inconsistency |
(-1) |
| Some or major uncertainty about directness |
(-1) or (-2) |
| Imprecise or sparse dataa |
(-1) |
| High probability of reporting bias |
(-1) |
|
aFew outcome events or observations or wide confident limits around an effect estimate. Adapted from [10]. | |
Bellomo and Bagshaw Critical Care 2006 10:232 doi:10.1186/cc5045 |
|