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Opioid versus opioid-free analgesia after surgical discharge: protocol for a systematic review and meta-analysis
  1. Charbel El-Kefraoui1,2,
  2. Ghadeer Olleik1,2,
  3. Marc-Aurele Chay3,
  4. Araz Kouyoumdjian1,4,
  5. Philip Nguyen-Powanda2,
  6. Fateme Rajabiyazdi1,2,
  7. Uyen Do1,2,
  8. Alexa Derksen5,6,
  9. Tara Landry7,
  10. Alexandre Amar-Zifkin8,
  11. Agnihotram V. Ramanakumar9,
  12. Marc-Olivier Martel10,
  13. Gabriele Baldini11,
  14. Liane Feldman1,4,
  15. Julio F Fiore Jr1,4
  1. 1 Steinberg-Bernstein Centre for Minimally Invasive Surgery and Innovation, McGill University Health Centre, Montreal, Quebec, Canada
  2. 2 Division of Experimental Surgery, McGill University, Montreal, Quebec, Canada
  3. 3 Faculty of Medicine, McGill University, Montreal, Quebec, Canada
  4. 4 Department of Surgery, McGill University, Montreal, Quebec, Canada
  5. 5 Child Health and Human Development Program, McGill University, Montreal, Quebec, Canada
  6. 6 Clinical Research Institute of Montreal, Montreal, Quebec, Canada
  7. 7 Bibliothèque de la Santé, Universite de Montreal, Montreal, Quebec, Canada
  8. 8 Medical Libraries, McGill University Health Centre, Montreal, Quebec, Canada
  9. 9 Department of Oncology, McGill University, Montreal, Quebec, Canada
  10. 10 Dentistry and Anesthesia, McGill University, Montreal, Quebec, Canada
  11. 11 Department of Anesthesia, McGill University, Montreal, Quebec, Canada
  1. Correspondence to Dr Julio F Fiore Jr; julio.fiorejunior{at}


Introduction Excessive prescribing after surgery has contributed to a public health crisis of opioid addiction and overdose in North America. However, the value of prescribing opioids to manage postoperative pain after surgical discharge remains unclear. We propose a systematic review and meta-analysis to assess the extent to which opioid analgesia impact postoperative pain intensity and adverse events in comparison to opioid-free analgesia in patients discharged after surgery.

Methods and analysis Major electronic databases (MEDLINE, Embase, Cochrane Library, Scopus, AMED, BIOSIS, CINAHL and PsycINFO) will be searched for multi-dose randomised-trials examining the comparative effectiveness of opioid versus opioid-free analgesia after surgical discharge. Studies published from January 1990 to July 2019 will be targeted, with no language restrictions. The search will be re-run before manuscript submission to include most recent literature. We will consider studies involving patients undergoing minor and major surgery. Teams of reviewers will, independently and in duplicate, assess eligibility, extract data and evaluate risk of bias. Our main outcomes of interest are pain intensity and postoperative vomiting. Study results will be pooled using random effects models. When trials report outcomes for a common domain (eg, pain intensity) using different scales, we will convert effect sizes to a common standard metric (eg, Visual Analogue Scale). Minimally important clinical differences reported in previous literature will be considered when interpreting results. Subgroup analyses defined a priori will be conducted to explore heterogeneity. Risk of bias will be assessed according to the Cochrane Collaboration's Risk of Bias Tool 2.0. The quality of evidence for all outcomes will be evaluated using the GRADE rating system.

Ethics and dissemination Ethical approval is not required since this is a systematic review of published studies. Our results will be published in a peer-reviewed journal and presented at relevant conferences. Further knowledge dissemination will be sought via public and patient organisations focussed on pain and opioid-related harms.

  • surgery
  • pain management
  • adult surgery

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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  • Contributors CEK, GB, LF and JF contributed to the conception and the design of the study. CEK and JF wrote the first draft of the protocol. CEK, GO, MAC, AK, PNP, FR, UD, AD, TL, AAZ, RA, MM, GB, LF and JF revised the protocol critically for important intellectual content. JF is the guarantor of this review. All authors have read and approved the final version of the manuscript to be published.

  • Funding This research is supported by funds from Fonds de Recherche du Québec-Santé granted to JF (Établissement de jeunes chercheurs, dossier #36799).

  • Competing interests JF has received grants from Merck and personal fees for consulting from Shionogi. LF has received grants from Merck and Johnson & Johnson.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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