|Evidence Quality Grading and Recommendation Strength|
|Evidence Quality for Each ES||Strength of Each Recommendation|
|High||A – Strong|
|• Well-designed and conducted RCTs||B – Moderate|
|Moderate||C – Weak|
|• RCTs with minor limitations||D – Against|
|• Well-conducted observational studies||E – Expert Opinion|
N – No Recommendation
|• RCTs with major limitations|
|• Observational studies with major limitations|
Reproduced from Smith (19).
ES indicates evidence statement; NHLBI, National Heart, Lung, and Blood Institute; and RCTs, randomized controlled trials.