There was evidence of convergent and construct validity of Physiotherapy Evidence Database quality scale for physiotherapy trials

Macedo, Luciana Gazzi; Elkins, Mark R.; Maher, Christopher G.; Moseley, Anne M.; Herbert, Robert D.; Sherrington, Catherine

doi:10.1016/j.jclinepi.2009.10.005

« Previous Next »Journal of Clinical Epidemiology
Volume 63, Issue 8 , Pages 920-925, August 2010

There was evidence of convergent and construct validity of Physiotherapy Evidence Database quality scale for physiotherapy trials

Luciana Gazzi Macedo
- Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia
- Corresponding author. Musculoskeletal Division, The George Institute for International Health, The University of Sydney, PO Box M201, Missenden Road, Camperdown, NSW 2050, Australia. Tel.: 61-2-9657-0392; fax: 61-2-8088-1335.
Mark R. Elkins
- Department of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia
Christopher G. Maher
- Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia
Anne M. Moseley
- Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia
Robert D. Herbert
- Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia
Catherine Sherrington
- Musculoskeletal Division, The George Institute for International Health, The University of Sydney, Sydney, New South Wales, Australia

Accepted 12 October 2009. published online 22 February 2010.

Abstract

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.

Study Design and Setting

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.

Conclusion

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.

Keywords: Randomized controlled trial, Validity, Physical therapy, Journal impact factor, Research methodology, Questionnaire