An international, consensus-derived Core Outcome Set for Cardiac Arrest effectiveness trials the COSCA initiativeHaywood, Kirstie L.a; Whitehead, Laurab; Perkins, Gavin D.bCurrent Opinion in Critical Care: June 2019 - Volume 25 - Issue 3 - p 226–233 doi: 10.1097/MCC.0000000000000612 CARDIOPULMONARY RESUSCITATION: Edited by Hans Friberg Buy SDC Abstract Author InformationAuthors Article MetricsMetrics Purpose of review Accurate and relevant assessment is essential to determining the impact of ill-health and the relative benefit of healthcare. This review details the recent development of a core outcome set for cardiac arrest effectiveness trials – the COSCA initiative. Recent findings The reported heterogeneity in outcome assessment and a lack of outcome reporting guidance were key triggers for the development of the COSCA. The historical failure of existing research to adequately capture the perspective of survivors and their family members in defining survival is described. Working collaboratively with international stakeholders – including survivors, family members and advocates – as research partners and participants ensured that a range of perspectives were considered throughout all stages of COSCA development. Three core domains and methods of assessment were recommended: survival – at 30 days or hospital discharge; neurological function assessed at 30 days or hospital discharge with the modified Rankin Scale; and health-related quality of life assessed at 90 days (as a minimum) with one of three generic measures. Summary The COSCA recommendation describes a small group of outcomes that should be reported as a minimum across large, randomized clinical effectiveness trials for cardiac arrest. aWarwick Research in Nursing bWarwick Clinical Trials Unit, Warwick Medical School, Warwick University, Gibbet Hill, Coventry CV4 7AL, UK Correspondence to Dr Kirstie L. Haywood, DPhil, BSc(Hons), PGCertHE, Associate Professor, Warwick Research in Nursing, Warwick Medical School, Warwick University, Gibbet Hill, Coventry CV4 7AL, UK. Tel: +44 24 7615 0616; e-mail: firstname.lastname@example.org Copyright © 2019 YEAR Wolters Kluwer Health, Inc. All rights reserved.