Document Type

Peer-Reviewed Article

Publication Date



Objective: The Consolidated Standards of Reporting Trials (CONSORT) recommends reporting adverse events (AEs) and dropouts (DOs) with their definitions. The purpose of this study was to identify how AEs and DOs were reported in randomized controlled trials (RCTs) of therapeutic exercise for knee osteoarthritis (OA).

Methods: Data sources were the Cochrane Library, EMBASE, PUBMED, and CINAHL. Databases were searched to identify RCTs of therapeutic exercise for Knee OA published from January 1, 1980, through July 23, 2020. Researchers independently extracted participant and intervention characteristics and determined whether a clear statement of and reasons for AEs and DOs existed. The primary outcome was exercise-related harm. Physiotherapy Evidence Database (PEDro) scoring described study quality and risk of bias. Descriptive and inferential statistics characterized results. Meta-analysis was not performed due to data heterogeneity.

Results: One hundred 13 studies (152 arms) from 25 countries were included with 5909 participants exercising. PEDro scores ranged from 4 to 9. Exercise intensity was not specified in 57.9% of exercise arms. Fifty studies (44.2%) included an AE statement and 24 (21.2%) reported AEs, yielding 297 patients. One hundred three studies (91.2%) had a DO statement. Sixteen studies (15.5%) provided reasons for DOs that could be classified as AEs among 39 patients, yielding a 13.1% increase in AEs. Thus, 336 patients (6.0%) experienced exercise-related harm among studies with a clear statement of AEs and DOs. A significant difference existed in misclassification of DOs pre- and post-CONSORT 2010 (12.2% vs 3.1%; X21 = 21.2).

Conclusions: In some studies, the reason for DOs could be considered AEs, leading to potential underreporting of harm. Improvements in reporting of harm were found pre-and post-CONSORT 2010. Greater clarity regarding AE and DO definitions and TherEx intensity are needed to determine safe dosing and mode of therapeutic exercise for knee OA.

Impact: More adherence to the CONSORT statement is needed regarding reporting of and defining AEs, DOs, and therapeutic exercise intensity; however, despite this, therapeutic exercise seems to be associated with minimal risk of harm.


Online ahead of print 26 June 2021.

Version posted is the publisher's uncorrected proof.

Published in its final edited form as:

Von Heideken, J., Chowdhry, S., Borg, J., James, K., & Iversen, M. D. (2021). Reporting of harm in randomized controlled trials of therapeutic exercise for knee osteoarthritis: A systematic review. Physical Therapy & Rehabilitation Journal, 101(10, pzab161).






Physical Therapy & Rehabilitation Journal






Oxford University Press



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