DOI: 10.1111/1471-0528.12657
Commentary
www.bjog.org
How to reduce unnecessary duplication: use PROSPERO D Moher,a A Booth,b L Stewartb a
Faculty of Medicine, Clinical Epidemiology Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada NIHR Centre for Reviews and Dissemination, University of York, York, UK Correspondence: D Moher, Clinical Epidemiology Program, Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Rd, Room L1288, Ottawa, ON K1H 8L6, Canada. Email [email protected]
b
Accepted 11 December 2013. Published Online 14 March 2014. Please cite this paper as: Moher D, Booth A, Stewart L. How to reduce unnecessary duplication: use PROSPERO. BJOG 2014;121:784–786.
In this issue of BJOG two systematic reviews are published addressing the same question, namely, is chewing gum effective in reducing postoperative ileus for women undergoing a caesarean section.1,2 Both reviews produce the same result, at least for one main outcome, time to first flatus, although both groups may have used different methods to arrive at their answer. For example, the eligibility criteria, or how they were implemented, might have differed between the reviews as each review arrived at a different number of included studies. Although this is not necessarily an example of discordant reviews,3 what will be obvious to most readers is a case of duplicate publication.4 Whether these are examples of unnecessary duplication5 can be assessed through a basic search of PubMed Health, The Cochrane Library and Medline, which identifies at least two published reviews covering the same intervention for abdominal surgery. These reviews were only referenced by Craciunas et al.1 Unfortunately neither of the reviews published here was registered on PROSPERO, an international prospective register for systematic review protocols.6 As such, the two groups are unlikely to have been aware of each other’s work, resulting in unplanned duplication. Similarly, neither report mentions the existence of an ongoing update of a review using the same intervention for intra-abdominal surgery, which was registered on PROSPERO in January 2013.7 Neither review reports the existence of a protocol— an approach that deviates from best practice.8,9 Sadly they are not alone. A review of 175 non-Cochrane reviews published in November 2004 indicates that only 14% reported working from an existing protocol.10 A more recent review examining systematic reviews published between January 2010 and May 2011 reported that
Commentary
www.bjog.org
How to reduce unnecessary duplication: use PROSPERO D Moher,a A Booth,b L Stewartb a
Faculty of Medicine, Clinical Epidemiology Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada NIHR Centre for Reviews and Dissemination, University of York, York, UK Correspondence: D Moher, Clinical Epidemiology Program, Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Rd, Room L1288, Ottawa, ON K1H 8L6, Canada. Email [email protected]
b
Accepted 11 December 2013. Published Online 14 March 2014. Please cite this paper as: Moher D, Booth A, Stewart L. How to reduce unnecessary duplication: use PROSPERO. BJOG 2014;121:784–786.
In this issue of BJOG two systematic reviews are published addressing the same question, namely, is chewing gum effective in reducing postoperative ileus for women undergoing a caesarean section.1,2 Both reviews produce the same result, at least for one main outcome, time to first flatus, although both groups may have used different methods to arrive at their answer. For example, the eligibility criteria, or how they were implemented, might have differed between the reviews as each review arrived at a different number of included studies. Although this is not necessarily an example of discordant reviews,3 what will be obvious to most readers is a case of duplicate publication.4 Whether these are examples of unnecessary duplication5 can be assessed through a basic search of PubMed Health, The Cochrane Library and Medline, which identifies at least two published reviews covering the same intervention for abdominal surgery. These reviews were only referenced by Craciunas et al.1 Unfortunately neither of the reviews published here was registered on PROSPERO, an international prospective register for systematic review protocols.6 As such, the two groups are unlikely to have been aware of each other’s work, resulting in unplanned duplication. Similarly, neither report mentions the existence of an ongoing update of a review using the same intervention for intra-abdominal surgery, which was registered on PROSPERO in January 2013.7 Neither review reports the existence of a protocol— an approach that deviates from best practice.8,9 Sadly they are not alone. A review of 175 non-Cochrane reviews published in November 2004 indicates that only 14% reported working from an existing protocol.10 A more recent review examining systematic reviews published between January 2010 and May 2011 reported that
