title: Meta-analysis: prophylactic drainage and bleeding complications in thyroid surgery.
abstract: OBJECTIVE
  To conduct a comprehensive systematic review and high-quality meta-analysis to determine whether prophylactic drain placement reduces adverse bleeding events in thyroid surgery.
  
  
  METHODS
  MEDLINE (OVID and PubMed), CENTRAL, CDSR, ACP Journal Club, DARE, EMBASE, PREMEDLINE, OLDMEDLINE, CINAHL, BIOSIS Previews, LILACS, KOREAMED, SAMED, IndMED, SIGLE, ScienceDirect, and INGENTACONNECT.
  
  
  METHODS
  Studies for evaluation included all prospective trials assessing the use of drainage in thyroid surgery. We excluded case studies, retrospective studies, reviews, and studies that had a "selective" method of postoperative drainage that was not defined or was based on surgeon preference. Search strategies were broad and based on Cochrane Collaboration search filters. There was no language restriction. Article selection was conducted by two independent reviewers under QUORUM guidelines.
  
  
  RESULTS
  Four hundred sixty-two articles were identified by the search strategy used, and 16 articles were included in the final review. Ten studies were randomized controlled trials, with 8 used for quantitative meta-analysis. No study showed a statistically significant benefit or harm with drain use. Meta-analysis of data estimated an odds ratio of 1.47 for reoperation for bleeding and 0.88 for visible hematoma for suction drains versus no drains. The results were not statistically significant, and 95% confidence intervals were wide.
  
  
  CONCLUSIONS
  The literature has insufficient evidence to recommend routine drainage in thyroid surgery. It is possible that drains may increase the risk of reoperation for bleeding, although the data are not statistically significant. If there is a benefit to drainage, absolute risk reductions of bleeding outcomes may not warrant routine use.
authors.affiliation: Department of Surgery, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia. sakennedy@mac.com
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Kennedy
authors.forename: Robert A
authors.initials: RA
authors.lastname: Irvine
authors.forename: Brian D
authors.initials: BD
authors.lastname: Westerberg
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhang
mesh_terms: D004322:Drainage; D006801:Humans; D011182:Postoperative Care; D019106:Postoperative Hemorrhage / Q000209:etiology / Q000517:prevention & control*; D013961:Thyroid Gland / Q000601:surgery*; D016896:Treatment Outcome