Evidence quality | Preponderance of benefit over harm | Balance of benefit and harm | Preponderance of harm over benefit |
---|---|---|---|
A. Well-designed RCTs | Strong recommendation | Option | Strong recommendation against |
B. RCT’s with minor limitations; overwhelming consistent evidence from observational studies | Recommendation | ||
C. Observational studies (case–control and cohort design) | Recommendation against | ||
D. Expert opinion; case reports; reasoning from first principles | Option | No recommendation |