ArticleSystematic review of movement-evoked pain versus pain at rest in postsurgical clinical trials and meta-analyses: A fundamental distinction requiring standardized measurementSrikandarajah, Sanjho; Gilron, Ian*Author Information Sponsorships or completing interests that may be relevant to content are disclosed at the end of this article. Department of Anesthesiology & Perioperative Medicine and Department of Pharmacology & Toxicology, Queen’s University, Kingston, Ontario, Canada *Corresponding author. Address: Department of Anesthesiology, Queen’s University and Kingston General Hospital, Victory 2 Pavilion, 76 Stuart St, Kingston, Ontario, Canada K7L 2V7. Tel.: +1 613 548 7827; fax: +1 613 548 1375. E-mail address:email@example.com Article history: Received 1 December 2010; Received in revised form 21 January 2011; Accepted 2 February 2011. ☆ This work was presented, in part, at the Canadian Anesthesiologists’ Society Annual Meeting, Vancouver, Canada, June 2009 and at the IASP World Pain Congress, Montreal, Canada August 2010. Pain: August 2011 - Volume 152 - Issue 8 - p 1734-1739 doi: 10.1016/j.pain.2011.02.008 Buy Metrics Abstract To estimate frequency of movement-evoked pain (MEP) measurement in human postsurgical investigations, we reviewed thoracotomy, knee arthroplasty, and hysterectomy clinical trials and meta-analyses. Only 39% of trials measured MEP and 52% failed to identify pain outcome as pain at rest (PAR) or MEP. Temporal trending did not suggest that MEP measurement is becoming more frequent. Trials measuring both MEP and PAR suggest that MEP is 95–226% more intense than PAR in the first 3 postoperative days. Among trials measuring MEP, 38% did not specify the physical maneuver used to assess MEP. Five of 7 meta-analyses reviewed (71%) did not distinguish between PAR and MEP, and none of the 7 meta-analyses declared the 20–59% of reviewed trials that had failed to identify their pain outcome as PAR or MEP. These results suggest an unchanging neglect of MEP in postsurgical pain trials and frequent failure to identify pain outcome as PAR or MEP. This is an important problem because MEP is usually more severe than PAR; MEP exerts a more direct adverse impact on postsurgical functional recovery and several current and novel pain treatments differentially affect MEP vs PAR. Failure to distinguish between PAR and MEP and standardize their measurement threatens trial precision and ability to identify interventions with the most clinically relevant effects on pain. We therefore recommend developing consistent terminology regarding PAR and MEP, considering inclusion of MEP as a pain outcome in every postsurgical trial, and standardizing measurement of PAR and MEP on a procedure-specific basis. An unchanging neglect for movement-evoked pain (MEP) measurement in postsurgical trials is revealed; we recommend considering MEP as a pain outcome in every postsurgical trial and standardizing its measurement. © 2011 Lippincott Williams & Wilkins, Inc.