BJOG Exchange
A report from #BlueJC: Can gum chewing prevent postoperative ileus? Papers discussed: • Craciunas L, Sajid MS, Ahmed AS. A systematic review and meta-analysis of randomised controlled trials reporting the role of chewing gum in preventing postoperative ileus in women undergoing caesarean section. BJOG 2014;121:793–9. • Zhu YP, Yao XD, Wang WJ, Zhang SL, Dai B, Ye DW. Effects of gum chewing on postoperative ileus after caesarean section: a meta-analysis of randomised controlled trials. BJOG 2014;121:787–92. Location: Twitter Number of participants: 13 Date of journal club: 25 June 2014 Number of tweets: 100 Paper summary: Participants Intervention Comparison Outcomes Study design Findings
Women who had postoperative ileus after caesarean section Chewing gum, with routine management Routine management only Time to first flatus, time to first bowel movement, and length of hospital stay Meta-analyses of randomised controlled trials Gum chewing reduced the time to first flatus and bowel movement after caesarean section. However, there was no difference in the length of hospital stay
Research literacy: PROSPERO As part of an international effort to improve the quality of systematic review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement published in 2009 recommended the registration of systematic review protocols. As a result, the Centre for Reviews and Dissemination (CRD) at the University of York, UK, developed PROSPERO, a free-to-access international database of prospectively registered systematic reviews in health and social care (http://www.crd.york.ac.uk/PROSPERO). The two systematic reviews (SRs) discussed have highlighted the resources spent on unnecessary duplication of SRs. Initiatives such as PROSPERO will hopefully reduce such duplications in the future.
Feedback on the study Definition of postoperative ileus The diagnosis of postoperative ileus (POI) was not clearly defined in these SRs. It was also unclear whether the same definition of POI had been used consistently in the primary studies included. Both SRs reported relevant surrogate outcomes, including time to first flatus, time to first bowel sounds, and time to first defecation. However, only Craciunas and co-workers meta-analysed the risks of POI and reported a significant reduction of POI (OR 0.36; 95% CI 0.19–0.69). Interpretation: heterogeneity, publication bias, and sensitivity analysis Both SRs reported significant statistical heterogeneity of the included studies. It was unclear what was the impact of this heterogeneity on the results of these SRs. Zhu and co-workers evaluated potential publication bias and presented their sensitivity analysis. Reassuringly, no significant publication bias was detected, and the results were not skewed by any individual studies. The clinical significance of the reported benefits The magnitude of effects were summarised differently in these SRs. Whereas Zhu and co-workers calculated the number of hours reduced from caesarean section to first flatus, first bowel sounds and movement, Craciunas and co-workers presented their data as standardised mean differences and odds ratios. Some argued the former approach was more clinically relevant. Moreover, the small reduction of time to bowel movement perhaps explained the lack of improvement on length of hospital stay.
Take-home messages The prospective registration of SRs and meta-analyses can reduce duplication and potentially improve the quality of SRs through prospective peer reviews. Prophylactic gum chewing after caesarean section promotes bowel motility, although the clinical benefits may be small.
Acknowledgements We are grateful for all contributions to this journal club. A transcript and a list of contributors can be viewed at http://bit.ly/1s2ThVA. The altmetric summary of this journal club paper can be viewed at: http://bit.ly/1oqpCiz. EYL Leung Women’s Health Research Unit, Queen Mary, University of London, London, UK About #BlueJC: Regular #BlueJC starts on the last Wednesday of each month (except December). For an introduction to #BlueJC, please refer to BJOG 2013;120:657–60. Further information is available on www.BJOG.org. Follow @BlueJCHost on Twitter to receive update #BlueJC news. Queries should be sent to
[email protected] or @BlueJCHost.
ª 2014 Royal College of Obstetricians and Gynaecologists
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