A core outcome set for future endometriosis research: an international consensus development study

To develop a core outcome set for endometriosis.

Consensus development study.


One hundred and sixteen healthcare professionals, 31 researchers, and 206 patient representatives.

Modified Delphi method and modified nominal group technique.

The final core outcome set includes three core outcomes for trials evaluating potential treatments for pain and other symptoms associated with endometriosis: overall pain; improvement in the most troublesome symptom; and quality of life. In addition, eight core outcomes for trials evaluating potential treatments for infertility associated with endometriosis were identified: viable intrauterine pregnancy confirmed by ultrasound; pregnancy loss, including ectopic pregnancy, miscarriage, stillbirth, and termination of pregnancy; live birth; time to pregnancy leading to live birth; gestational age at delivery; birthweight; neonatal mortality; and major congenital abnormalities. Two core outcomes applicable to all trials were also identified: adverse events and patient satisfaction with treatment.

Using robust consensus science methods, healthcare professionals, researchers, and women with endometriosis have developed a core outcome set to standardise outcome selection, collection, and reporting across future randomised controlled trials and systematic reviews evaluating potential treatments for endometriosis.

Tweetable abstract
@coreoutcomes for future #endometriosis research have been developed @jamesmnduffy.


JMN Duffy
M Hirsch
M Vercoe
J Abbott
C Barker
B Collura
R Drake
JLH Evers
M Hickey
AW Horne
ML Hull
S Kolekar
S Lensen
NP Johnson
V Mahajan
BW Mol
A-S Otter
L Puscasiu
MB Rodriguez
L Rombauts
A Vail
R Wang
CM Farquhar
endo:outcomes – an International Collaboration Harmonising Outcomes and Outcome Measures for Endometriosis Research


Journal: BJOG: An International Journal of Obstetrics & Gynaecology
Pages: -
Year: 2020
DOI: 10.1111/1471-0528.16157

Further Study Information

Current Stage: Completed
Date: October 2015 - October 2017
Funding source(s): Catalyst Fund, the Royal Society of New Zealand, and Endometriosis Millennium Fund, Royal College of Obstetricians and Gynaecologists.

Health Area

Disease Category: Gynaecology

Disease Name: Endometriosis

Target Population

Age Range: 13 - 51

Sex: Female

Nature of Intervention: Any

Stakeholders Involved

- Clinical experts
- Consumers (patients)
- Researchers

Study Type

- COS for clinical trials or clinical research


- Delphi process
- Consensus meeting
- Nominal group technique (NGT)
- Systematic review

Potential core outcomes were identi?ed through a systematic review of previously published endometriosis trials. The long list of potential core outcomes was entered into a modi?ed Delphi method, which facilitated individual stakeholder group convergence towards consensus outcomes. These outcomes were entered into a face-to-face consensus development meeting. Using a modi?ed nominal group technique, consensus outcomes were further prioritised to identify the ?nal core outcome set for endometriosis.