TABLE I.

Evidence levels and recommendation grades used in the consensus meeting^a

Item	Source or quality
Evidence
i	Meta-analysis of well-designed controlled studies; high-quality randomized trial
ii	At least one well-designed study; lower-quality randomized trial
iii	Quasi-experimental study—for example, nonrandomized, uncontrolled, case–control
iv	Non-experimental study—for example, comparative, case studies
v	Case reports and clinical examples
Recommendation
A	Type i or consistent findings from multiple studies of types ii, iii, or iv
B	Type ii, iii, or iv, findings generally consistent
C	Type ii, iii, or iv, inconsistent findings
D	Little or no empiric evidence

^aAdapted from Somerfield et al., 2000 ¹⁹.