This categorization takes into account the size and the
uncertainty associated with treatment effects and emphasizes
clinical significance rather than statistical significance.
This methodology appropriately restricts conclusions to the
comparisons made in trials. For example, in trials that
compare two interventions without a control group, the
categorization can only be used to make inferences about
the relative effectiveness of the two interventions, not about
the effectiveness of one intervention compared to no intervention.
Skewed and categorical data were not categorized for
clinical significance.
The quality of each trial was independently assessed by
two reviewers using the PEDro scale.5 Any disagreements
were resolved by an independent third person (reviewers
did not rate their own trials). The PEDro scale assesses
10 key design features important for minimizing bias
and interpreting between-group differences. It rates trials
according to whether they did or did not use random
allocation; conceal allocation; demonstrate baseline similarity;
blind subjects, therapists and assessors; obtain outcome
measures from more than 85% of subjects; provide
measures of variability; use intention-to-treat analyses;
and perform between-group statistical comparisons. Ratings
were based on the written text and not on personal
communications.