There was evidence of convergent and construct validity of Physiotherapy Evidence Database quality scale for physiotherapy trials.
OBJECTIVE
To evaluate the convergent and construct validity of the Physiotherapy Evidence Database (PEDro) scale used to rate the methodological quality of randomized trials in physiotherapy.


METHODS
PEDro total scores and individual-item scores were extracted from 9,456 physiotherapy trials indexed on PEDro. Convergent validity was tested by comparing PEDro total scores with three other quality scales. Construct validity was tested by regressing the PEDro score and individual-item scores with the Institute for Scientific Information Web of Knowledge impact factors (IF) and SCImago journal rankings (SJR) for the journals in which the trials were published.


RESULTS
Testing of convergent validity revealed correlations with the other quality scales ranging from 0.31 to 0.69. The PEDro total score was weakly but significantly associated with IF and SJR (P < 0.0001). Eight of the 10 individual scale items that contribute to the PEDro total score were significantly associated with IF.


CONCLUSIONS
This study provides preliminary evidence of the convergent and construct validity of the PEDro total score and the construct validity of eight individual scale items.
Macedo
Luciana Gazzi
LG
Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia. lmacedo@george.org.au
Elkins
Mark R
MR
Maher
Christopher G
CG
Moseley
Anne M
AM
Herbert
Robert D
RD
Sherrington
Catherine
C
D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D019317:Evidence-Based Medicine / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D026741:Physical Therapy Modalities / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000379:methods / Q000592:standards*; D011795:Surveys and Questionnaires / Q000592:standards; D016896:Treatment Outcome