Core Outcome Measures in Effectiveness Trials

Core outcome set for research studies evaluating treatments for twin–twin transfusion syndrome

General Information


Perry, H. Duffy, J. M. N. Reed, K. Baschat, A. Deprest, J. Hecher, K. Lewi, L. Lopriore, E. Oepkes, D. Khalil, A. Coroyannakis, C. Duffy, D. Giallongo, E. Turier, H. Toms, J. Lundie, K. Paramanantham, K. Burton, L. Windsor, S. Francis, S. the International Collaboration to Harmonise Outcomes for Twin-Twin Transfusion, Syndrome


Ultrasound in Obstetrics and Gynecology
Further Study Information

Funding source(s):
This study was supported by TAMBA. H.P. is supported by a grant from the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South London at King’s College Hospital NHS Foundation Trust. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. J.D. is funded by the Great Ormond Street Hospital Charity fund, the Wellcome Trust (WT101957) and Engineering and Physical Sciences Research Council (ESPRC) (NS/A000027/1) via GIFT-surg. L.L. is a clinical researcher funded by the Fonds Wetenschappelijk Onderzoek Vlaanderen (FWO 1804718N).

Health Area

Disease Category

Disease Name
Feto-fetal transfusion
Twin-Twin Transfusion Syndrome

Target Population

Age Range


Nature / type of Intervention


Delphi process
Literature review
Nominal group technique (NGT)

An international steering group comprising healthcare professionals, researchers and patients with experience of TTTS guided the development of this COS. Potential core outcomes, identified through a comprehensive literature review and supplemented by outcomes suggested by the steering group, were entered into a three-round Delphi survey. Healthcare professionals, researchers, and patients or relatives of patients who had experienced TTTS were invited to participate. Consensus was defined a priori using the 15%/70% definition of the Core Outcome Measures in Effectiveness Trials (COMET) initiative. The modified nominal group technique was used to evaluate the consensus outcomes in a face-to-face consultation meeting and identify the final COS.

Stakeholders Involved

Clinical experts
Consumers (patients)

Study Type

COS for clinical trials or clinical research

The site uses cookies, some may have been set already. Please refer to our privacy policy & cookie usage statement.
If you continue to use the site we'll assume you're happy to accept the cookies.