Sports Medicine

, Volume 46, Issue 2, pp 293–294 | Cite as

High Risk of Bias and Low Transparency in “How Effective are F-MARC Injury Prevention Programs for Soccer Players? A Systematic Review and Meta-Analysis”

  • Kristian ThorborgEmail author
  • Kasper Krommes
  • Ernest Esteve
  • Mikkel Bek Clausen
  • Else Marie Bartels
  • Michael Skovdal Rathleff
Letter to the Editor

We have read with great interest and attention the paper entitled “How effective are F-MARC injury prevention programs for soccer players? A systematic review and meta-analysis” published in Sports Medicine [1]; however, we are somewhat surprised that it has been accepted for publication as it fails to meet basic requirements for reporting of systematic reviews as described in the Preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement [2].

It appears to be a different analysis from a previous protocol by the same authors entitled “Meta-analysis on efficacy of the “FIFA 11+” injury prevention program in athletes”, first registered on 29 September 2014 and revised on 14 October 2014 in the International prospective register of systematic reviews (PROSPERO), but not referred to in the published article [1] (see the following link:

Such a lack of transparency when registering and...


Systematic Review Soccer Player Injury Rate Prefer Reporting Item Bias Tool 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



All authors have contributed substantially to the conception, design and drafting of this letter, and/or revising it critically for important intellectual content, as well as approval of the final version.

Compliance with Ethical Standards


Kristian Thorborg is supported by the Department of Orthopaedic Surgery, Sports Orthopedic Research Center-Copenhagen (SORC-C), Amager-Hvidovre Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. Else Marie Bartels/Parker Institute is funded by the OAK foundation. No sources of funding were used to assist in the preparation of this Letter to the Editor.

Conflicts of interest

Kristian Thorborg, Kasper Krommes, Ernest Esteve, Mikkel Bek Clausen, Else Marie Bartels, and Michael Skovdal Rathleff declare that they lodged a protocol for a systematic review with a similar scope to the article by Al Attar et al. with PROSPERO on 2 July 2015. This is available at the following link: The investigators were unaware at that time that Al Attar et al. had submitted their manuscript to Sports Medicine for publication.

All authors declare they have no other potential conflicts of interest in relation to the content of this letter.

Editor’s note

Al Attar et al. submitted their manuscript to Sports Medicine on 7 May 2015.

Thorborg et al. registered their protocol on PROSPERO on 2 July 2015.

The manuscript by Al Attar et al. was published online on 24 September 2015.


  1. 1.
    Al Attar WS, Soomro N, Pappas E, et al. How effective are F-MARC injury prevention programs for soccer players? A systematic review and meta-analysis. Sports Med (Epub 24 Sep 2015).Google Scholar
  2. 2.
    Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. J Clin Epidemiol. 2009;62(10):1006–12.CrossRefPubMedGoogle Scholar
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    Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available at:
  4. 4.
    Steffen K, Emery CA, Romiti M, et al. High adherence to a neuromuscular injury prevention programme (FIFA 11+) improves functional balance and reduces injury risk in Canadian youth female football players: a cluster randomised trial. Br J Sports Med. 2013;47(12):794–802.CrossRefPubMedGoogle Scholar
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    Furlan AD, Pennick V, Bombardier C, et al. 2009 updated method guidelines for systematic reviews in the Cochrane Back Review Group. Spine (Phila Pa 1976). 2009;34(18):1929–41.Google Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Kristian Thorborg
    • 1
    • 2
    Email author
  • Kasper Krommes
    • 1
    • 2
  • Ernest Esteve
    • 1
    • 2
    • 3
  • Mikkel Bek Clausen
    • 1
    • 2
    • 4
  • Else Marie Bartels
    • 5
  • Michael Skovdal Rathleff
    • 6
    • 7
  1. 1.Department of Orthopaedic Surgery, Sports Orthopedic Research Center-Copenhagen (SORC-C), Amager-Hvidovre Hospital, Faculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
  2. 2.Physical Medicine and Rehabilitation Research-Copenhagen (PMR-C), Amager-Hvidovre HospitalCopenhagen University HospitalCopenhagenDenmark
  3. 3.SportclinicPhysiotherapy and Sports Training CenterGironaSpain
  4. 4.Bachelor’s Degree Programme in Physiotherapy, Department of Physiotherapy and Occupational Therapy, Faculty of Health and TechnologyMetropolitan University CollegeCopenhagenDenmark
  5. 5.The Parker InstituteCopenhagen University Hospital, Bispebjerg and FrederiksbergCopenhagenDenmark
  6. 6.Research Unit for General Practice in Aalborg, Clinical InstituteAalborg UniversityAalborgDenmark
  7. 7.Department of Occupational Therapy and PhysiotherapyAalborg University HospitalAalborgDenmark

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