Development of a core outcome set for mechanical ventilation trials

Abstract

There is inconsistency in the selection and measurement of outcomes in clinical trials of mechanically ventilated critically ill patients. This presents challenges when comparing trials, and particularly when undertaking meta-analysis of trial data. A core outcome set (COS) is a minimum set of standardised outcomes that should be reported in every trial of a specific intervention. The aim of this PhD, therefore, was to develop a COS for use in future trials where the aim of the intervention is to modify the duration of mechanical ventilation. COS are developed using consensus methods; the most popular of these is the Delphi Technique, which uses anonymous feedback between rounds of questionnaires to reach a consensus opinion on a topic. Little is known about the validity of the methodology used to perform a Delphi study, so a nested randomised trial was included to investigate the impact of different feedback mechanisms on final consensus. Mixed consensus methods were used to develop this COS. A large, international, online Delphi study was performed followed by 2 consensus webinars with representatives from the Delphi panel, with additional input from a separate patient representative group teleconference. Participants represented 4 main stakeholder groups, patients, clinicians, researchers and industry experts. The Delphi ran over 3 rounds; Round 1 included 24 outcomes obtained by systematic review. During this round a further 23 outcomes were proposed and added by participants. Numbers of participants completing each round were 200, 178 and 161 respectively. Participants were randomised after the first round into 3 groups each receiving feedback in different forms to facilitate the nested study investigating the impact of feedback mechanisms on the final outcome of the Delphi. A total of 19 outcomes gained consensus through the Delphi process and were discussed at the consensus webinars and the patient teleconference. The outcomes in the final COS were agreed across all meetings and are mortality, health-related quality of life, duration of mechanical ventilation, reintubation, length of stay and successful extubation. Agreement has also been reached on how these outcomes should be measured and defined, using a process of systematic review and consensus meetings. The nested randomised study suggested that the method of feedback may impact the voting behaviour of participants and may influence the outcomes that are chosen.

Date of Award	Dec 2023
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	Northern Ireland Department for the Economy
Supervisor	Danny McAuley (Supervisor), Bronagh Blackwood (Supervisor) & Mike Clarke (Supervisor)