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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.

The Improvisers Cookbook presents a collection of contemporary experimental improvised practices developed during the COVID19 pandemic (2020-2022). Using newly developed interactive software (TIAALS) this research generated a novel approach (the 'Mushwork') which assisted in archiving and exploring the agency of an expanding community over a time of considerable social and creative change. The Improvisers Cookbook reflects a specific context and network of improvising players in order to 'track the social process', to uncover the agency of community in an emergent contemporary setting. This has been undertaken through an auto-sociological account that utilized practitioner social knowledge to investigate recent improvisational development. A thesis presented as non-linear and interactive which has iteratively been informed by the social and digitally enhanced practices of contemporary improvised practice. Three themes of contemporary digital working practice have been identified. These are 1. newly developed relationships within cyber-spaces (furnishing), 2. expanded membership through cyber-communities (fashioning), and 3. myth making techniques that have emerged from human-machine relationships (fictioning). The increased use of technology for telematic music, digital curation, and hybrid digital/physical performance is challenging traditional aesthetics, demographics and narratives of experimental improvised practice. These pandemic creative practices have afforded critiques of existing dominant histories by centering and celebrating previously marginalized practices and lineages of the field. This is a cookbook of cultural, historical, temporal and fantastical recipes for creative living and activism.

Waiting times for elective surgery have grown steadily over time in many countries and were recently heightened by the COVID-19 pandemic. The overall aim of this thesis is to identify opportunities to improve the efficiency of health systems, in particular to minimise major bottle necks that hinder patient throughput over the elective surgical care pathways. The health systems research in this thesis uses two research methodologies relevant to each of the two research elements. These are a portfolio of systematic reviews and a descriptive study. First, a portfolio of systematic reviews was completed to synthesise and collate global evidence on policy strategies and interventions to reduce long waiting times for elective surgeries. The second component investigated concerns of HCW towards COVID-19 vaccination using a descriptive study methodology. In the first component, the electronic search in the five bibliographic databases yielded 7543 records and 92 eligible articles were identified with the updated search as 21 quasi-experimental, 61 cohort, 7 systematic reviews, and 3 experimental studies. Considering the relevance and validity of evidence presented for numerous interventions, this component of the thesis presented as seven sub-reviews listed for seven major strategic areas namely; referral management, patient prioritisation, prevent surgery cancellations, perioperative time management, public private partnership, quality improvement methods, waiting time targets. In the second component, the overall results confirmed that a majority (93.5%) of the HCW were vaccinated and only 6.5% declined the vaccine. Among the vaccine declined group, primary level education was the single socio-demographic barrier associated with not receiving the COVID-19 vaccine and most of this group were health assistants. Combining these two elements shows that the ongoing problem of long waiting times for elective surgeries could be minimised by strong vaccination policies and systematic implementation of effective waiting time strategies into surgical care pathways that cause delays.

Clinical trials are crucial in the development of efficient healthcare interventions. Choice of outcome measure to estimate the efficacy of an intervention is a critical decision in a study. The National Institute of Health (NIH) definition working group defines 'clinical endpoint' as "a characteristic or variable that reflects how a patient feels, functions or survives" and "a surrogate endpoint is a biomarker intended to substitute for a clinical endpoint that should predict clinical benefit or harm or lack of both". Composite endpoints combine two or more components to form a single outcome, which helps to increase the event rate. Critical care studies have challenges in the analysis of commonly used composite outcome measures. The overarching aim of this PhD was to investigate methodological issues related to the use of surrogate and composite outcome measures in critical care trials. The project comes under the umbrella of outcome measures, and it is divided into two studies. Study 1 examines the variability and validity of surrogate outcome measures and study 2 explores the composite outcome measures in critical care. Three different techniques were used in this thesis: Systematic review, survey, and statistical analysis of secondary data. The initial literature review discussed different intervention development models, phase II designs and surrogate models. A systematic review of 48 studies published in six journals in the critical care category with the highest impact factor at the time was included in this review. The review aimed to generate a list of surrogate outcome measures reported in critical care studies, determine the variability in the outcome reporting and create a smaller list of potential early phase endpoints for critical care trials. Critical care clinicians and general healthcare researchers were surveyed to gather their views on phase II studies, surrogate outcomes, and standardisation of outcomes. Critical care clinicians and researchers were also asked about their views on the impact of these outcomes in clinical decision making, study progress and overall relevance of the outcomes identified in the systematic review. The critical care researchers and clinicians considered organ failure outcomes as the most influential outcomes followed by the length of stay outcomes, disease severity scores, routinely collected physiology variables and finally biomarkers. The subsequent statistical analysis investigated the issue of analysed duration outcomes, Sequential Organ Failure Assessment (SOFA) score, PaCO2/FiO2ratio (PF ratio) and Oxygenation Index (OI). A joint modelling approach for analysing mechanical ventilation in the presence of a terminal event was explored. The association between the outcome measures such as the score, PaCO2/FiO2ratio (PF ratio), Oxygenation Index (OI) and the clinical endpoint, mortality was investigated using joint modelling. Joint modelling estimates were compared with cox regression estimates. Mediation analysis was used to estimate the direct and indirect effects. The estimates based on mediation analysis were compared was joint modelling estimates. The study proposes the following core outcomes for early phase MV studies 1. Mortality; 2. Duration of MV; 3. Length of stay in ICU; 4. Length of stay in hospital; 5. SOFA; 6. OI; 7. PF ratio; The study on composite outcome measures included a literature review of composite outcomes in general and the utility of the VFD score as an outcome in critical care studies. The first approach tested whether any of the count data models such as Poisson, Zero Inflated Poisson (ZIP) and Logit-Poisson hurdle model provided a better fit for the VFD score compared to the traditional t-test. The win-ratio method is widely used as an approach to analysing composites with components arranged in hierarchical order. The usefulness of different combinations of mortality and MV outcomes was investigated. The use of an additional outcome, SOFA as a tie-breaker for win-ratio analysis was explored. A two-part hurdle was a promising approach to analysing VFD. Future studies could investigate the sample size requirement. Win-ratio analysis was easy to understand and simple to implement. For early phase studies, mortality, and duration of MV was recommended as outcomes to categorise patients into winner and loser.