An anal fistula is defined as an abnormal tract connecting the anorectal canal and the perianal skin and is lined with granulation tissue. It is a commonly encountered problem with an incidence of around 1 per 5,000 people per year in European countries. Men are more likely to be affected than women, with a peak incidence around the age of 40. Over 90% of the anal fistulas are due to infected anal glands in the anal canal. These fistulas are called cryptoglandular anal fistulas. The most commonly reported symptoms are pain and discharge, causing social embarrassment and loss of quality of life.
The interventional studies evaluating the effectiveness of interventions for anal fistula show heterogeneity in outcome reporting. In addition, there is considerable variability in outcome definitions, outcome measurement instruments, and timing of outcome assessment. This limits research quality and complicates evidence synthesis. The development of a Core Outcome Set (COS), encouraged by the Core Outcome Measures in Effectiveness Trials (COMET) initiative, will reduce heterogeneity in outcome reporting and minimize outcome reporting bias. A COS represents an agreed minimum standardized set of outcomes that should be assessed and reported in all interventional studies for a specific condition.
This study will follow a multi-step approach as recommended by the guidelines for COS development published by COMET initiative. In the first step potential clinician-important and patient-important outcomes will be identified by a systematic review of the literature and patient interviews. These outcomes will in the second step be prioritized by patients, clinicians, and (clinical) researchers in up to three web-based Delphi surveys. The third step is a face-to-face consensus meeting to decide on the definitive COS.
Astrid J.H.M. Machielsen, BSc; Department of Surgery and Colorectal Surgery, Maastricht University Medical Centre+, The Netherlands; Faculty of Health, Medicine & Life Sciences, Maastricht University, The Netherlands; Email: ajhmmachielsen@gmail.com
Nusrat Iqbal, BSc (Hons), MBBS, MRCS; Clinical Research Fellow, Robin Phillips’ Fistula Research Unit, St Mark’s Hospital, London, UK; Department of Surgery and Cancer, Imperial College London, UK
Merel L. Kimman, PhD; Senior HTA researcher, Department of Clinical Epidemiology and Medical Technology Assessment; Care and Public Health Research Institute (CAPHRI), Maastricht University Medical Centre+, The Netherlands
Kapil Sahnan, BSc, MBBS, MRCS, PhD; Post-doctoral Fellow, Robin Phillips’ Fistula Research Unit, St Mark’s Hospital, London, UK; Department of Surgery and Cancer, Imperial College London, UK
Samuel O. Adegbola, BSc (Hons), MBBS, MRCS, PhD; Post-doctoral Fellow,
Robin Phillips’ Fistula Research Unit, St Mark’s Hospital, London, UK; Department of Surgery and Cancer, Imperial College London, UK
Jos Kleijnen, MD, PhD; Professor of Systematic Reviews in Healthcare, Department of Family Medicine; Care and Public Health Research Institute (CAPHRI), Maastricht University, The Netherlands
Ugo Grossi, MD, PhD; Colorectal Surgeon, Tertiary Referral Pelvic Floor and Incontinence Centre, Regional Hospital Treviso, Italy
Phil J. Tozer, MBBS, MD(Res), FRCS; Colorectal Surgeon, Robin Phillips’ Fistula Research Unit, St Mark’s Hospital, London, UK; Department of Surgery and Cancer, Imperial College London, UK
Stephanie O. Breukink, MD, PhD; Colorectal Surgeon, Department of Surgery and Colorectal Surgery, Maastricht University Medical Centre+, The Netherlands
Disease Category: Gastroenterology
Disease Name: Cryptoglandular perianal fistula
Age Range: 18 - 100
Sex: Either
Nature of Intervention: Drug, Surgery
- Clinical experts
- Consumers (patients)
- Researchers
- COS for clinical trials or clinical research
- COS for practice
- Consensus meeting
- Delphi process
- Interview
- Systematic review
This study will follow a multi-step approach as recommended by the guidelines for COS development published by COMET initiative. In the first step potential clinician-important and patient-important outcomes will be identified by a systematic review of the literature and patient interviews. These outcomes will in the second step be prioritized by patients, clinicians, and (clinical) researchers in up to three web-based Delphi surveys. The results will be summarized and fed back anonymously after each round to facilitate convergence to a consensus opinion. Stakeholders will be asked to score the candidate outcomes on a 9-point Likert scale with respect to how important they think the outcomes are in evaluating treatment effectiveness. The third step is a face-to-face consensus meeting to decide on the definitive COS.
The outcomes which are currently reported in interventional studies for anal fistula are predominantly determined by clinicians and (clinical) researchers and may lack outcomes that are important from the patient’s perspective. To ensure that the outcomes included in the COS are important for patients, clinicians, and (clinical) researchers, all groups will be involved in the development of the COS for anal fistula as recommended by the Core Outcome Set-STAndards for Reporting (COS-STAR). The COMET Checklist for Public Research Partners will be used to optimize the involvement of patients. The Study Management Group (AM, NI, MK, UG, PT, SB and patient representatives from The United Kingdom and The Netherlands) is responsible for the design and conduct of this study.