title: Re-infection outcomes following one- and two-stage surgical revision of infected hip prosthesis in unselected patients: protocol for a systematic review and an individual participant data meta-analysis.
abstract: BACKGROUND
  Several aggregate published reviews have compared the effectiveness of one- and two-stage surgical revision to prevent re-infection following prosthetic hip infection and have reported inconsistent results. In addition, there were several features of these previous reviews which limited the validity of the findings. In the absence of a well-designed clinical trial, we propose the Global Infection Orthopaedic Management (INFORM) collaboration, a worldwide collaborative systematic review and meta-analysis of individual participant data (IPD) to address the existing uncertainties.
  
  
  METHODS
  Cohort studies (prospective or retrospective) and randomised controlled trials conducted in unselected patients with infection treated exclusively by one- or two-stage revision and reporting re-infection outcomes within 2 years of revision will be retrieved by searching the following databases: MEDLINE, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and the WHO International Clinical Trials Registry Platform. Reference lists of relevant studies will be manually scanned and there will be email contact with investigators of grey literature and conference abstracts. Investigators will be invited to join the Global INFORM collaboration and share their individual level data. The primary outcome of the analyses will be incidence of re-infection within 2 years of commencement of revision surgery. Primary analyses will be conducted comparing the one-stage to the two-stage surgical revision. IPD analyses will be based on Cox proportional hazard (PH) models estimated for each study separately. Study-specific log hazard ratios will be combined using random-effects meta-analysis with fixed-effects meta-analysis in subsidiary analyses. Hazard ratios for re-infection according to different individual level characteristics such as sex, age groups, body mass index and comorbidities will also be assessed.
  
  
  CONCLUSIONS
  The analyses will enable a consistent approach to the definition of re-infection outcomes, more detailed analyses under a broader range of circumstances and exploration of potential sources of heterogeneity and produce much more valid and precise estimates of re-infection outcomes.
  
  
  BACKGROUND
  PROSPERO 2015: CRD42015016664.
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, Learning and Research Building (Level 1), Southmead Hospital, University of Bristol, Southmead Road, Bristol, BS10 5NB, UK. setor.kunutsor@bristol.ac.uk.
authors.forename: Setor K
authors.initials: SK
authors.lastname: Kunutsor
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, Learning and Research Building (Level 1), Southmead Hospital, University of Bristol, Southmead Road, Bristol, BS10 5NB, UK. Michael.Whitehouse@bristol.ac.uk.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Whitehouse
authors.affiliation: North Bristol NHS Trust, Bristol, BS10 5NB, UK. Jason.Webb@nbt.nhs.uk.
authors.forename: Jason
authors.initials: J
authors.lastname: Webb
authors.affiliation: Royal Devon and Exeter NHS Foundation Trust, Exeter, EX2 7JU, UK. andrewtoms@doctors.org.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Toms
authors.affiliation: Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, Sheffield, S5 7AU, UK. Ian.Stockley@sth.nhs.uk.
authors.forename: Ian
authors.initials: I
authors.lastname: Stockley
authors.affiliation: Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK. ataylor@doctors.org.uk.
authors.forename: Adrian
authors.initials: A
authors.lastname: Taylor
authors.affiliation: Cardiff and Vale University Health Board, Llandough, CF5 2LD, UK. sajones@doctors.org.uk.
authors.forename: Stephen
authors.initials: S
authors.lastname: Jones
authors.affiliation: Royal Devon and Exeter NHS Foundation Trust, Exeter, EX2 7JU, UK. matthewwilson@nhs.net.
authors.forename: Matthew
authors.initials: M
authors.lastname: Wilson
authors.affiliation: The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, SY10 7AG, UK. Benjamin.Burston@rjah.nhs.uk.
authors.forename: Ben
authors.initials: B
authors.lastname: Burston
authors.affiliation: Wrightington, Wigan and Leigh NHS Foundation Trust, Wigan, WN6 9EP, UK. tim.n.board@wwl.nhs.uk.
authors.forename: Tim
authors.initials: T
authors.lastname: Board
authors.affiliation: The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, SY10 7AG, UK. JP.Whittaker@rjah.nhs.uk.
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Whittaker
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, Learning and Research Building (Level 1), Southmead Hospital, University of Bristol, Southmead Road, Bristol, BS10 5NB, UK. ashley.blom@bristol.ac.uk.
authors.forename: Ashley W
authors.initials: AW
authors.lastname: Blom
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, Learning and Research Building (Level 1), Southmead Hospital, University of Bristol, Southmead Road, Bristol, BS10 5NB, UK. andy.beswick@bristol.ac.uk.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Beswick
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D002985:Clinical Protocols; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007239:Infections / Q000150:complications / Q000601:surgery*; D011183:Postoperative Complications / Q000601:surgery*; D012086:Reoperation; D012107:Research Design; D000078202:Systematic Reviews as Topic; D015201:Meta-Analysis as Topic