16
Table 1. Strength of Recommendation and Quality of
Evidence
Strength of
Recommendation/
Quality of Evidence
Clarity of Balance
Between Desirable
and Undesirable
Effects
Methodological
Quality of
Supporting
Evidence (examples) Implications
S/H
Desirable effects
clearly outweigh
undesirable effects,
or vice versa
Consistent
evidence from well-
performed RCTs
or exceptionally
strong evidence
from unbiased
observational studies
Recommendation can apply
to most patients in most
circumstances. Further
research is unlikely to
change our confidence in
the estimate of effect.
S/M
Desirable effects
clearly outweigh
undesirable effects,
or vice versa
Evidence from RCTs
with important
limitations
(inconsistent results,
methodological
flaws, indirect,
or imprecise)
or exceptionally
strong evidence
from unbiased
observational studies
Recommendation can apply
to most patients in most
circumstances. Further
research (if performed) is
likely to have an important
impact on our confidence
in the estimate of effect and
may change the estimate.
S/L
Desirable effects
clearly outweigh
undesirable effects,
or vice versa
Evidence for at least
one critical outcome
from observational
studies, RCTs with
serious flaws or
indirect evidence
Recommendation may
change when higher quality
evidence becomes available.
Further research (if
performed) is likely to have
an important impact on our
confidence in the estimate
of effect and is likely to
change the estimate.
S/VL
(very rarely
applicable)
Desirable effects
clearly outweigh
undesirable effects,
or vice versa
Evidence for at least
one critical outcome
from unsystematic
clinical observations
or very indirect
evidence
Recommendation may
change when higher quality
evidence becomes available.
Any estimate of effect for at
least one critical outcome is
very uncertain.
W/H
Desirable effects
closely balanced with
undesirable effects
Consistent
evidence from well-
performed RCTs
or exceptionally
strong evidence
from unbiased
observational studies
e best action may
differ depending on
circumstances or patients
or societal values. Further
research is unlikely to
change our confidence in
the estimate of effect.