title: A Core Outcome Set for the Benefits and Adverse Events of Bariatric and Metabolic Surgery: The BARIACT Project.
abstract: BACKGROUND
  Bariatric and metabolic surgery is used as a treatment for patients with severe and complex obesity. However, there is a need to improve outcome selection and reporting in bariatric surgery trials. A Core Outcome Set (COS), an agreed minimum set of outcomes reported in all studies of a specific condition, may achieve this. Here, we present the development of a COS for BARIAtric and metabolic surgery Clinical Trials-the BARIACT Study.
  
  
  RESULTS
  Outcomes identified from systematic reviews and patient interviews informed a questionnaire survey. Patients and health professionals were surveyed three times and asked to rate the importance of each item on a 1-9 scale. Delphi methods provided anonymised feedback to participants. Items not meeting predefined criteria were discarded between rounds. Remaining items were discussed at consensus meetings, held separately with patients and professionals, where the COS was agreed. Data sources identified 2,990 outcomes, which were used to develop a 130-item questionnaire. Round 1 response rates were moderate but subsequently improved to above 75% for other rounds. After rounds 2 and 3, 81 and 14 items were discarded, respectively, leaving 35 items for discussion at consensus meetings. The final COS included nine items: "weight," "diabetes status," "cardiovascular risk," "overall quality of life (QOL)," "mortality," "technical complications of the specific operation," "any re-operation/re-intervention," "dysphagia/regurgitation," and "micronutrient status." The main limitation of this study was that it was based in the United Kingdom only.
  
  
  CONCLUSIONS
  The COS is recommended to be used as a minimum in all trials of bariatric and metabolic surgery. Adoption of the COS will improve data synthesis and the value of research data. Future work will establish methods for the measurement of the outcomes in the COS.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Karen D
authors.identifier: http://orcid.org/0000-0003-0510-4290
authors.initials: KD
authors.lastname: Coulman
authors.affiliation: Department of Upper GI and Bariatric Surgery, Taunton and Somerset NHS Foundation Trust, Taunton, Somerset, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Hopkins
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Sara T
authors.initials: ST
authors.lastname: Brookes
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Katy
authors.identifier: http://orcid.org/0000-0003-4923-3000
authors.initials: K
authors.lastname: Chalmers
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Barry
authors.initials: B
authors.lastname: Main
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Amanda
authors.initials: A
authors.lastname: Owen-Smith
authors.affiliation: University of Exeter Medical School, Medical Research, Exeter, United Kingdom.|Department of Diabetes and Endocrinology, Taunton and Somerset NHS Foundation Trust, Taunton, Somerset, United Kingdom.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Andrews
authors.affiliation: Department of General Surgery, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Byrne
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|NIHR CLAHRC West, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors.forename: Jenny L
authors.identifier: http://orcid.org/0000-0002-6488-5472
authors.initials: JL
authors.lastname: Donovan
authors.affiliation: Clinical Trials and Evaluation Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Graziella
authors.initials: G
authors.lastname: Mazza
authors.affiliation: Clinical Trials and Evaluation Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Barnaby C
authors.identifier: http://orcid.org/0000-0002-5101-9487
authors.initials: BC
authors.lastname: Reeves
authors.affiliation: Clinical Trials and Evaluation Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom.
authors.forename: Chris A
authors.identifier: http://orcid.org/0000-0002-9624-2615
authors.initials: CA
authors.lastname: Rogers
authors.affiliation: University of Birmingham, School of Sport, Exercise & Rehabilitation Sciences, Edgbaston, Birmingham, United Kingdom.
authors.forename: Janice L
authors.identifier: http://orcid.org/0000-0002-7312-3226
authors.initials: JL
authors.lastname: Thompson
authors.affiliation: Department of Upper GI and Bariatric Surgery, Taunton and Somerset NHS Foundation Trust, Taunton, Somerset, United Kingdom.
authors.forename: Richard
authors.initials: R
authors.lastname: Welbourn
authors.affiliation: Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Wordsworth
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|Division of Surgery, Head & Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Blazeby
mesh_terms: D001291:Attitude of Health Personnel; D001294:Attitude to Health; D050110:Bariatric Surgery / Q000592:standards*; D006801:Humans; D010361:Patients / Q000523:psychology; D066231:Surgeons / Q000523:psychology; D006113:United Kingdom