Table 1 Factors assessed in critically appraising the evidence
Factors that might decrease quality of evidence | Factors that might increase quality of evidence |
|---|---|
• Lack of allocation concealment • Lack of blinding (particularly for subjective outcomes) • Failure to adhere to an intention to treat analysis • Stopping early for benefit • Selective outcome reporting • Poor matching of groups in nonrandomized studies or inappropriate comparison group (e.g., children with more serious behavioural problems placed in control group) • Absence of treatment fidelity assessment • Inadequate description of intervention and those delivering intervention • Insufficient follow-up period or lack of reporting on losses to follow-up | • Large magnitude of effect • Plausible confounding, which would reduce a demonstrated effect • Dose-response gradient (increased intensity of treatment leads to enhanced benefits) |