Development of a Core Outcome Set for research on critically ill obstetric patients: A study protocol

BACKGROUND: Current data on critical illness during pregnancy are insufficient for evidence-based decision making. Core outcome sets are promoted to improve reporting of outcomes important to decision makers. We aim to develop a Core Outcome Set for research on critically ill obstetric patients (COSCO study). METHODS: We will perform a systematic review of studies on critical illness in pregnancy and focus groups or interviews with women who were critically ill while being pregnant. These data will inform an international Delphi survey where stakeholders will rank proposed outcomes. Selected outcomes will be brought forward to a consensus meeting where core outcomes will be defined. We will then complete a second consensus process to define measures for each core outcome. CONCLUSION: The Core Outcome Set on Critically ill Obstetric patients study aims to develop a set of core outcomes to be part of all studies on critically ill obstetric patients. Implementation of this core outcome set will help improve future research efforts.Trial registration: This study is registered on the COMET-initiative website (COS #916). This systematic review is registered on PROSPERO (CRD #42017071944).