title: Core Outcomes for Colorectal Cancer Surgery: A Consensus Study.
abstract: BACKGROUND
  Colorectal cancer (CRC) is a major cause of worldwide morbidity and mortality. Surgical treatment is common, and there is a great need to improve the delivery of such care. The gold standard for evaluating surgery is within well-designed randomized controlled trials (RCTs); however, the impact of RCTs is diminished by a lack of coordinated outcome measurement and reporting. A solution to these issues is to develop an agreed standard "core" set of outcomes to be measured in all trials to facilitate cross-study comparisons, meta-analysis, and minimize outcome reporting bias. This study defines a core outcome set for CRC surgery.
  
  
  RESULTS
  The scope of this COS includes clinical effectiveness trials of surgical interventions for colorectal cancer. Excluded were nonsurgical oncological interventions. Potential outcomes of importance to patients and professionals were identified through systematic literature reviews and patient interviews. All outcomes were transcribed verbatim and categorized into domains by two independent researchers. This informed a questionnaire survey that asked stakeholders (patients and professionals) from United Kingdom CRC centers to rate the importance of each domain. Respondents were resurveyed following group feedback (Delphi methods). Outcomes rated as less important were discarded after each survey round according to predefined criteria, and remaining outcomes were considered at three consensus meetings; two involving international professionals and a separate one with patients. A modified nominal group technique was used to gain the final consensus. Data sources identified 1,216 outcomes of CRC surgery that informed a 91 domain questionnaire. First round questionnaires were returned from 63 out of 81 (78%) centers, including 90 professionals, and 97 out of 267 (35%) patients. Second round response rates were high for all stakeholders (>80%). Analysis of responses lead to 45 and 23 outcome domains being retained after the first and second surveys, respectively. Consensus meetings generated agreement on a 12 domain COS. This constituted five perioperative outcome domains (including anastomotic leak), four quality of life outcome domains (including fecal urgency and incontinence), and three oncological outcome domains (including long-term survival).
  
  
  CONCLUSIONS
  This study used robust consensus methodology to develop a core outcome set for use in colorectal cancer surgical trials. It is now necessary to validate the use of this set in research practice.
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|Severn School of Surgery, Bristol, United Kingdom.
authors: Angus G K
authors: http://orcid.org/0000-0002-2601-9258
authors: AG
authors: McNair
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Robert N
authors: RN
authors: Whistance
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Rachael O
authors: RO
authors: Forsythe
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Rhiannon
authors: R
authors: Macefield
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Jonathan
authors: http://orcid.org/0000-0002-8704-6399
authors: J
authors: Rees
authors: Department of General Surgery, North Bristol NHS Trust, Bristol, United Kingdom.
authors: Anne M
authors: AM
authors: Pullyblank
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Kerry N L
authors: KN
authors: Avery
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors: Sara T
authors: ST
authors: Brookes
authors: Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Michael G
authors: MG
authors: Thomas
authors: Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Paul A
authors: PA
authors: Sylvester
authors: Colorectal Consumer Liaison Group, National Cancer Research Institute, London, United Kingdom.
authors: Ann
authors: A
authors: Russell
authors: Colorectal Consumer Liaison Group, National Cancer Research Institute, London, United Kingdom.
authors: Alfred
authors: A
authors: Oliver
authors: Academic Department of Surgery, University of Birmingham, Birmingham, United Kingdom.
authors: Dion
authors: D
authors: Morton
authors: Department of Surgery, St Mark's Hospital and Academic Institute, Harrow, United Kingdom.
authors: Robin
authors: R
authors: Kennedy
authors: Academic Surgical Unit, St James' University Hospital NHS Trust, Leeds, United Kingdom.
authors: David G
authors: DG
authors: Jayne
authors: Centre for Ethics in Medicine, University of Bristol, Bristol, United Kingdom.
authors: Richard
authors: R
authors: Huxtable
authors: Colorectal Site Specific Group, Somerset, Wiltshire, Avon & Gloucestershire, South West Cancer Network, Bristol, United Kingdom.
authors: Roland
authors: R
authors: Hackett
authors: Centre for Statistics in Medicine and Oxford Clinical Trials Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
authors: Susan J
authors: http://orcid.org/0000-0003-4573-5257
authors: SJ
authors: Dutton
authors: Department of Colorectal Surgery, Plymouth Hospitals NHS Trust, Plymouth, United Kingdom.
authors: Mark G
authors: http://orcid.org/0000-0002-0668-3311
authors: MG
authors: Coleman
authors: Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Mia
authors: M
authors: Card
authors: Clinical Trials Research Unit, University of Leeds, Leeds, United Kingdom.
authors: Julia
authors: J
authors: Brown
authors: Centre for Surgical Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.|Division of Surgery Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, United Kingdom.
authors: Jane M
authors: JM
authors: Blazeby
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000601:surgery*; D003697:Delphi Technique; D005260:Female; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000592:standards / Q000706:statistics & numerical data; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D011795:Surveys and Questionnaires; D016896:Treatment Outcome