The CROWN Initiative: journal editors invite researchers to develop core outcomes in women's health


  • On behalf of Chief Editors of Journals participating in The CROWN Initiative (Appendix 1).

  • For further information please visit the CROWN Initiative webpage under Special Features.

Clinical trials, systematic reviews and guidelines compare beneficial and non-beneficial outcomes following interventions. Often, however, various studies on a particular topic do not address the same outcomes, making it difficult to draw clinically useful conclusions when a group of studies is looked at as a whole.[1] This problem was recently thrown into sharp focus by a systematic review of interventions for preterm birth prevention, which found that among 103 randomised trials, no fewer than 72 different outcomes were reported.[2] There is a growing recognition among clinical researchers that this variability undermines consistent synthesis of the evidence, and that what is needed is an agreed standardised collection of outcomes – a ‘core outcomes set’ – for all trials in a specific clinical area.[1] Recognising that the current inconsistency is a serious hindrance to progress in our specialty, the editors of over 50 journals related to women's health have come together to support The CoRe Outcomes in WomeN's health (CROWN) Initiative (Box 1).

Box 1. Aims of The CROWN Initiative

  1. Form a consortium among all gynaecology-obstetrics and related journals to promote core outcome sets in all areas of our specialty.
  2. Encourage researchers to develop core outcome sets using robust consensus methodology involving multiple stakeholders, including patients.
  3. Strongly encourage the reporting of results for core outcome sets.
  4. Organise robust peer-review and effective dissemination of manuscripts describing core outcome sets.
  5. Facilitate embedding of core outcome sets in research practice, working closely with researchers, reviewers, funders and guideline makers.

Development of consensus is required around a set of well-defined, relevant and feasible outcomes for all trials concerning particular obstetric and gynecologic health conditions, such as preterm birth, incontinence, infertility and menstrual problems. With so many subspecialties involved, this is no easy task. Duplication of effort can be avoided by working with the Core Outcome Measures in Effectiveness Trials (COMET) Initiative, which is working towards core data sets for all medical specialties.[3] Production of trustworthy core outcome sets will require engagement with patients, healthcare professionals, researchers, industry and regulators, and the employment of scientifically robust consensus methods.[1] The data for these core outcome sets, once agreed upon, should be collected in trials and reported in publications as standard practice in the future.

Journal editors now invite researchers to take the lead in beginning this work. What will we do as editors to support them and their colleagues? First, we are drawing wide attention to The CROWN Initiative by publishing this editorial in the journals listed below. We shall ensure that the global research community, which includes our many reviewers, is aware of the need for core outcome sets. Submissions which describe development of core outcome sets, if deemed acceptable after peer review, will be effectively disseminated.

Our collaboration is not for enforcing harmony at the expense of innovation. To quote from the COMET home page ( ‘The existence or use of a core outcome set does not imply that outcomes in a particular trial should be restricted to those in the relevant core outcome set. Rather, there is an expectation that the core outcomes will be collected and reported, making it easier for the results of trials to be compared, contrasted and combined as appropriate; while researchers continue to explore other outcomes as well.’ We also expect that as new or superior ways of capturing outcomes emerge, core outcome sets will themselves need updating.

Producing, disseminating and implementing core outcome sets will ensure that critical and important outcomes with good measurement properties are incorporated and reported. We believe this is the next important step in advancing the usefulness of research, in informing readers, including guideline and policy developers, who are involved in decision-making, and in improving evidence-based practice.


The CROWN Initiative is grateful to James Duffy (Trainee Scientific Editor, BJOG) and Louisa Waite (Assistant Editor, BJOG) for the drafting, revision and coordination required for the preparation of this article.

Disclosure of interests

None to declare.

Appendix 1

The CROWN Initiative includes the following journals, in alphabetical order (correct on 13th May 2014, up to date list available at

  1. Acta Obstetricia et Gynecologica Scandinavica
  2. American Journal of Obstetrics & Gynecology
  3. American Journal of Perinatology
  4. Archives of Gynecology and Obstetrics
  5. Australian and New Zealand Journal of Obstetrics and Gynaecology
  6. Best Practice & Research: Clinical Obstetrics & Gynaecology
  7. Birth: Issues in Perinatal Care
  8. BJOG: An International Journal of Obstetrics and Gynaecology
  9. BMC Pregnancy and Childbirth
  10. BMC Women's Health
  11. Climacteric
  12. Clinical Obstetrics and Gynecology
  13. Clinics in Perinatology
  14. Cochrane Menstrual Disorders and Subfertility Group
  15. Cochrane Pregnancy and Childbirth Group
  16. Contraception
  17. Current Opinion in Obstetrics and Gynecology
  18. European Journal of Obstetrics & Gynecology and Reproductive Biology
  19. Fertility and Sterility
  20. Fetal Diagnosis and Therapy
  21. Ginekologia Polska
  22. Gynecological Surgery
  23. Gynecologic Oncology
  24. Gynecologic Oncology Reports
  25. Human Fertility
  26. Human Reproduction
  27. Human Reproduction Update
  28. Hypertension in Pregnancy
  29. International Journal of Fertility and Sterility
  30. International Breastfeeding Journal
  31. International Journal of Gynecology & Obstetrics
  32. International Urogynecology Journal
  33. Journal of Family Planning and Reproductive Health Care
  34. Journal of Gynecologic Oncology
  35. Journal of Lower Genital Tract Disease
  36. Journal of Midwifery & Women's Health
  37. Journal of Obstetrics & Gynaecology
  38. Journal of Obstetrics and Gynaecology Canada
  39. Journal of Obstetric, Gynecologic & Neonatal Nursing
  40. Journal of Perinatal and Neonatal Nursing
  41. Journal of Perinatal Medicine
  42. Maturitas
  43. MCN The American Journal of Maternal Child Nursing
  44. Menopause Review (Przegląd Menopauzalny)
  45. Menopause: The Journal of The North American Menopause Society
  46. Neurourology and Urodynamics
  47. Obstetrics & Gynecology
  48. Paediatric and Perinatal Epidemiology
  49. Placenta
  50. Prenatal Diagnosis
  51. Reproductive Health
  52. The Breast Journal
  53. The European Journal of Contraception and Reproductive Health Care
  54. The Obstetrician & Gynaecologist (TOG)
  55. Twin Research and Human Genetics
  56. Ultrasound in Obstetrics & Gynecology