Questioning approaches to consent in time critical obstetric trials: findings from a mixed-methods study.

OBJECTIVE: Trial legislation enables research to be conducted without prior consent (RWPC) in emergency situations, yet this approach has rarely been used in time-critical obstetric trials. This study explored views and experiences of antenatal recruitment and consent and RWPC in an emergency intrapartum randomised clinical trial. DESIGN: Embedded, mixed-methods study within a trial, involving questionnaires, recorded recruitment discussions, interviews and focus groups in the first 13 months of trial recruitment (December 2020-January 2022). SETTING: COPE is a double-blind randomised controlled trial, comparing the effectiveness of carboprost or oxytocin as first-line treatment of postpartum haemorrhage. PARTICIPANTS: Two hundred and eighty-six people (190 women/96 birth partners), linked to 198/380 (52%) COPE recruits participated in the embedded study. Of these, 272 completed a questionnaire (178 women/94 birth partners), 22 were interviewed (19 women/3 birth partners) and 16 consent discussions with 12 women were recorded. Twenty-seven staff took part in three focus groups and nine staff were interviewed. RESULTS: Participants recommended that information about the study should be more accessible antenatally for those who wish to be informed. Most women and staff did not think it would be appropriate to seek consent during pregnancy or early labour as it may cause 'unnecessary panic' and lead to research waste, as most women would not become eligible. There was support for the use of RWPC as COPE interventions are used in standard clinical practice and viewed as low risk. Women who were approached about the trial while having a postpartum haemorrhage also supported RWPC as they could not recall research discussions. CONCLUSIONS: Findings support the use of RWPC for time-critical interventions, and raise questions about the appropriateness of other commonly used consent pathways, including antenatal consent and verbal assent.

Stakeholders' perspectives on clinical trial acceptability and approach to consent within a limited timeframe: a mixed methods study.

OBJECTIVES: The Bronchiolitis Endotracheal Surfactant Study (BESS) is a randomised controlled trial to determine the efficacy of endo-tracheal surfactant therapy for critically ill infants with bronchiolitis. To explore acceptability of BESS, including approach to consent within a limited time frame, we explored parent and staff experiences of trial involvement in the first two bronchiolitis seasons to inform subsequent trial conduct. DESIGN: A mixed-method embedded study involving a site staff survey, questionnaires and interviews with parents approached about BESS. SETTING: Fourteen UK paediatric intensive care units. PARTICIPANTS: Of the 179 parents of children approached to take part in BESS, 75 parents (of 69 children) took part in the embedded study. Of these, 55/69 (78%) completed a questionnaire, and 15/69 (21%) were interviewed. Thirty-eight staff completed a questionnaire. RESULTS: Parents and staff found the trial acceptable. All constructs of the Adapted Theoretical Framework of Acceptability were met. Parents viewed surfactant as being low risk and hoped their child's participation would help others in the future. Although parents supported research without prior consent in studies of time critical interventions, they believed there was sufficient time to consider this trial. Parents recommended that prospective informed consent should continue to be sought for BESS. Many felt that the time between the consent process and intervention being administered took too long and should be 'streamlined' to avoid delays in administration of trial interventions. Staff described how the training and trial processes worked well, yet patients were missed due to lack of staff to deliver the intervention, particularly at weekends. CONCLUSION: Parents and staff supported BESS trial and highlighted aspects of the protocol, which should be refined, including a streamlined informed consent process. Findings will be useful to inform proportionate approaches to consent in future paediatric trials where there is a short timeframe for consent discussions. TRIAL REGISTRATION NUMBER: ISRCTN11746266.

The perception of risk in contracting and spreading COVID-19 amongst individuals, households and vulnerable groups in England: a longitudinal qualitative study.

BACKGROUND: Social distancing restrictions to manage the COVID-19 pandemic were put in place from March 2020 in the United Kingdom (UK), with those classed as "highly clinically vulnerable" advised to shield entirely and remain at home. However, personal risk perception has been shown to comprise of various elements beyond those outlined in the national pandemic guidance. It is unclear whether those deemed COVID-19 vulnerable identified as high-risk to COVID-19 and thus complied with the relevant advice. The aim of this research is to explore the perception of risk in catching and spreading COVID-19, amongst individuals from individual households, and vulnerable groups in a region of the UK. METHODS: Two individual, semi-structured interviews were conducted, four-weeks apart, with adults living in households in the Liverpool City Region. At the follow-up interview, participants were given the option of using photo-elicitation to guide the discussion. Reflexive thematic analysis was employed to conceptualise themes. The qualitative analysis was underpinned with symbolic interactionism. RESULTS: Twenty-seven participants (13:14 males:females, and 20 with a vulnerable risk factor to COVID-19) completed a baseline interview, and 15 of these completed a follow-up interview four-weeks later. Following thematic analysis, two overarching themes were conceptualised, with subthemes discussed: theme 1) Confusion and trust in the risk prevention guidance; and theme 2) Navigating risk: compliance and non-compliance with public health guidance. CONCLUSION: Participants developed their own understanding of COVID-19 risk perception through personal experience and comparison with others around them, irrespective of vulnerability status. COVID-19 guidance was not complied with as intended by the government, and at times even rejected due to lack of trust. The format in which future pandemic guidance is conveyed must be carefully considered, and take into account individuals' experiences that may lead to non-compliance. The findings from our study can inform future public health policy and interventions for COVID-19 and future pandemics.

Establishing and augmenting views on the acceptability of a paediatric critical care randomised controlled trial (the FEVER trial): a mixed methods study.

OBJECTIVE: To explore parent and staff views on the acceptability of a randomised controlled trial investigating temperature thresholds for antipyretic intervention in critically ill children with fever and infection (the FEVER trial) during a multi-phase pilot study. DESIGN: Mixed methods study with data collected at three time points: (1) before, (2) during and (3) after a pilot trial. SETTING: English, Paediatric Intensive Care Units (PICUs). PARTICIPANTS: (1) Pre-pilot trial focus groups with pilot site staff (n=56) and interviews with parents (n=25) whose child had been admitted to PICU in the last 3 years with a fever and suspected infection, (2) Questionnaires with parents of randomised children following pilot trial recruitment (n=48 from 47 families) and (3) post-pilot trial interviews with parents (n=19), focus groups (n=50) and a survey (n=48) with site staff. Analysis drew on Sekhon et al's theoretical framework of acceptability. RESULTS: There was initial support for the trial, yet some held concerns regarding the proposed temperature thresholds and not using paracetamol for pain or discomfort. Pre-trial findings informed protocol changes and training, which influenced views on trial acceptability. Staff trained by the FEVER team found the trial more acceptable than those trained by colleagues. Parents and staff found the trial acceptable. Some concerns about pain or discomfort during weaning from ventilation remained. CONCLUSIONS: Pre-trial findings and pilot trial experience influenced acceptability, providing insight into how challenges may be overcome. We present an adapted theoretical framework of acceptability to inform future trial feasibility studies. TRIAL REGISTRATION NUMBERS: ISRCTN16022198 and NCT03028818.

Can they stomach it? Parent and practitioner acceptability of a trial comparing gastric residual volume measurement versus no gastric residual volume in UK NNU and PICUs: a feasibility study.

BACKGROUND: Routine measurement of gastric residual volume (GRV) to guide feeding in neonatal and paediatric intensive care is widespread. However, this practice is not evidence based and may cause harm. As part of a feasibility study, we explored parent and practitioner views on the acceptability of a trial comparing GRV measurement or no GRV measurement. METHODS: A mixed-methods study involving interviews and focus groups with practitioners and interviews with parents with experience of tube feeding in neonatal and/or paediatric intensive care. A voting system recorded closed question responses during practitioner data collection, enabling the collection of quantitative and qualitative data. Data were analysed using thematic analysis and descriptive statistics. RESULTS: We interviewed 31 parents and nine practitioners and ran five practitioner focus groups (n=42). Participants described how the research question was logical, and the intervention would not be invasive and potential benefits of not withholding the child's feeds. However, both groups held concerns about the potential risk of not measuring GRV, including delayed diagnosis of infection and gut problems, increased risk of vomiting into lungs and causing discomfort or pain. Parent's views on GRV measurement and consent decision making were influenced by their views on the importance of feeding in the ICU, their child's prognosis and associated comorbidities or complications. CONCLUSIONS: The majority of parents and practitioners viewed the proposed trial as acceptable. Potential concerns and preferences were identified that will need careful consideration to inform the development of the proposed trial protocol and staff training.

Optimal outcome measures for a trial of not routinely measuring gastric residual volume in neonatal care: a mixed methods consensus process.

BACKGROUND: Routine measurement of gastric residual volume to guide feeding is widespread in neonatal units but not supported by high-quality evidence. Outcome selection is critical to trial design. OBJECTIVE: To determine optimal outcome measures for a trial of not routinely measuring gastric residual volume in neonatal care. DESIGN: A focused literature review, parent interviews, modified two-round Delphi survey and stakeholder consensus meeting. PARTICIPANTS: Sixty-one neonatal healthcare professionals participated in an eDelphi survey; 17 parents were interviewed. 19 parents and neonatal healthcare professionals took part in the consensus meeting. RESULTS: Literature review generated 14 outcomes, and parent interviews contributed eight additional outcomes; these 22 outcomes were then ranked by 74 healthcare professionals in the first Delphi round where four further outcomes were proposed; 26 outcomes were ranked in the second round by 61 healthcare professionals. Five outcomes were categorised as 'consensus in', and no outcomes were voted 'consensus out'. 'No consensus' outcomes were discussed and voted on in a face-to-face meeting by 19 participants, where four were voted 'consensus in'. The final nine consensus outcomes were: mortality, necrotising enterocolitis, time to full enteral feeds, duration of parenteral nutrition, time feeds stopped per 24 hours, healthcare-associated infection; catheter-associated bloodstream infection, change in weight between birth and neonatal discharge and pneumonia due to milk aspiration. CONCLUSIONS AND RELEVANCE: We have identified outcomes for a trial of no routine measurement of gastric residual volume to guide feeding in neonatal care. This outcome set will ensure outcomes are important to healthcare professionals and parents.

Determining Optimal Outcome Measures in a Trial Investigating No Routine Gastric Residual Volume Measurement in Critically Ill Children.

BACKGROUND: Choosing trial outcome measures is important. When outcomes are not clinically relevant or important to parents/patients, trial evidence is less likely to be implemented into practice. This study aimed to determine optimal outcome measures for a trial of no routine gastric residual volume (GRV) measurement in critically ill children. METHODS: A mixed-methods approach was used: a focused literature review, parent and clinician interviews, a modified 2-round Delphi, and a stakeholder consensus meeting. RESULTS: The review generated 13 outcomes. Fourteen pediatric intensive care unit (PICU) parents proposed 3 additional outcomes; these 16 were then rated by 28 clinicians in Delphi round 1. Six further outcomes were proposed, and 22 outcomes were rated in the second round. No items were voted "consensus out." The 18 "no-consensus" items were voted in a face-to-face meeting by 30 participants. The final 12 outcome measures were time to reach energy targets, ventilator-associated pneumonia, vomiting, time enteral feeds withheld per 24 hours, necrotizing enterocolitis, length of invasive ventilation, PICU length of stay, mortality, change in weight and markers of feed intolerance (parenteral nutrition administered), feed formula altered, and change to postpyloric feeds all secondary to feed intolerance. CONCLUSION: We have identified 12 outcomes for a trial of no GRV measurement through a multistage process, seeking views of parents and clinicians.

Gastric residual volume measurement in British neonatal intensive care units: a survey of practice.

OBJECTIVE: Despite little evidence, the practice of routine gastric residual volume (GRV) measurement to guide enteral feeding in neonatal units is widespread. Due to increased interest in this practice, and to examine trial feasibility, we aimed to determine enteral feeding and GRV measurement practices in British neonatal units. DESIGN AND SETTING: An online survey was distributed via email to all neonatal units and networks in England, Scotland and Wales. A clinical nurse, senior doctor and dietitian were invited to collaboratively complete the survey and submit a copy of relevant guidelines. RESULTS: 95/184 (51.6%) approached units completed the survey, 81/95 (85.3%) reported having feeding guidelines and 28 guidelines were submitted for review. The majority of units used intermittent (90/95) gastric feeds as their primary feeding method. 42/95 units reported specific guidance for measuring and interpreting GRV. 20/90 units measured GRV before every feed, 39/90 at regular time intervals (most commonly four to six hourly 35/39) and 26/90 when felt to be clinically indicated. Most units reported uncertainty on the utility of aspirate volume for guiding feeding decisions; 13/90 reported that aspirate volume affected decisions 'very much'. In contrast, aspirate colour was reported to affect decisions 'very much' by 37/90 of responding units. Almost half, 44/90, routinely returned aspirates to the stomach. CONCLUSIONS: Routine GRV measurement is part of standard practice in British neonatal units, although there was inconsistency in how frequently to measure or how to interpret the aspirate. Volume was considered less important than colour of the aspirate.

Routine gastric residual volume measurement to guide enteral feeding in mechanically ventilated infants and children: the GASTRIC feasibility study.

BACKGROUND: The routine measurement of gastric residual volume to guide the initiation and delivery of enteral feeding is widespread in paediatric intensive care and neonatal units, but has little underlying evidence to support it. OBJECTIVE: To answer the question: is a trial of no gastric residual volume measurement feasible in UK paediatric intensive care units and neonatal units? DESIGN: A mixed-methods study involving five linked work packages in two parallel arms: neonatal units and paediatric intensive care units. Work package 1: a survey of units to establish current UK practice. Work package 2: qualitative interviews with health-care professionals and caregivers of children admitted to either setting. Work package 3: a modified two-round e-Delphi survey to investigate health-care professionals' opinions on trial design issues and to obtain consensus on outcomes. Work package 4: examination of national databases to determine the potential eligible populations. Work package 5: two consensus meetings of health-care professionals and parents to review the data and agree consensus on outcomes that had not reached consensus in the e-Delphi study. PARTICIPANTS AND SETTING: Parents of children with experience of ventilation and tube feeding in both neonatal units and paediatric intensive care units, and health-care professionals working in neonatal units and paediatric intensive care units. RESULTS: Baseline surveys showed that the practice of gastric residual volume measurement was very common (96% in paediatric intensive care units and 65% in neonatal units). Ninety per cent of parents from both neonatal units and paediatric intensive care units supported a future trial, while highlighting concerns around possible delays in detecting complications. Health-care professionals also indicated that a trial was feasible, with 84% of staff willing to participate in a trial. Concerns expressed by junior nurses about the intervention arm of not measuring gastric residual volumes were addressed by developing a simple flow chart and education package. The trial design survey and e-Delphi study gained consensus on 12 paediatric intensive care unit and nine neonatal unit outcome measures, and identified acceptable inclusion and exclusion criteria. Given the differences in physiology, disease processes, environments, staffing and outcomes of interest, two different trials are required in the two settings. Database analyses subsequently showed that trials were feasible in both settings in terms of patient numbers. Of 16,222 children who met the inclusion criteria in paediatric intensive care units, 12,629 stayed for > 3 days. In neonatal units, 15,375 neonates < 32 weeks of age met the inclusion criteria. Finally, the two consensus meetings demonstrated 'buy-in' from the wider UK neonatal communities and paediatric intensive care units, and enabled us to discuss and vote on the outcomes that did not achieve consensus in the e-Delphi study. CONCLUSIONS AND FUTURE WORK: Two separate UK trials (one in neonatal units and one in paediatric intensive care units) are feasible to conduct, but they cannot be combined as a result of differences in outcome measures and treatment protocols, reflecting the distinctness of the two specialties. TRIAL REGISTRATION: Current Controlled Trials ISRCTN42110505. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 23. See the NIHR Journals Library website for further project information.

Nurses looking after babies and children on intensive care units in the UK usually pass a tube and aspirate whatever food or fluid is in the baby's stomach before they give a feed. The idea is to ensure that the stomach is not overdistended with food and prevent the baby vomiting or, worse, aspirating food into the lungs. However, there is little justification for this practice. It is rarely done in many other countries. It may not be pleasant for the child and perhaps is unnecessary. Some experts have suggested that the policy should be evaluated in a randomised controlled trial. This would mean allocating a large number of children at random to either have the stomach aspirated before feeds, or not. Such a trial would be a major undertaking and we are unsure if parents or staff would be willing to allow children to participate. The aim of this study was to see if it is possible to conduct such a large trial in the UK. Two surveys (of 119 units) showed us that regularly measuring the stomach contents when starting and increasing feeds is common practice for both newborn and older children in UK intensive care units. However, in some countries, such as France, this practice is rarely done. We asked 31 parents and 51 health-care professionals about a future study. Overall, parents were supportive of a trial if it was explained to them well by a knowledgeable and caring professional, and if they were approached at the right time. Some concerns were expressed about not picking up complications early if gastric residual volume was not measured. Health-care professionals were also mainly positive about a future trial, but mentioned similar concerns about not picking up complications early and the difficulty of changing a long-standing routine practice. Parents suggested study outcomes that were important to them. These, along with other outcomes, were voted on in a further survey of 106 professionals and at face-to-face meetings involving 41 participants. Overall, our findings suggest that a trial is feasible to perform and acceptable to parents. However, because of differences in both treatments and important outcomes between children's intensive care units and newborn baby intensive care units, two trials would be needed, one in each type of intensive care unit. These two trials will test whether or not the benefits of not measuring gastric residual volume (e.g. improved calorie intake) outweigh the potential harms (e.g. delayed diagnosis of complications).

A Fully Integrated Real-Time Detection, Diagnosis, and Control of Community Diarrheal Disease Clusters and Outbreaks (the INTEGRATE Project): Protocol for an Enhanced Surveillance System.

BACKGROUND: Diarrheal disease, which affects 1 in 4 people in the United Kingdom annually, is the most common cause of outbreaks in community and health care settings. Traditional surveillance methods tend to detect point-source outbreaks of diarrhea and vomiting; they are less effective at identifying low-level and intermittent food supply contamination. Furthermore, it can take up to 9 weeks for infections to be confirmed, reducing slow-burn outbreak recognition, potentially impacting hundreds or thousands of people over wide geographical areas. There is a need to address fundamental problems in traditional diarrheal disease surveillance because of underreporting and subsequent unconfirmed infection by patients and general practitioners (GPs); varying submission practices and selective testing of samples in laboratories; limitations in traditional microbiological diagnostics, meaning that the timeliness of sample testing and etiology of most cases remains unknown; and poorly integrated human and animal surveillance systems, meaning that identification of zoonoses is delayed or missed. OBJECTIVE: This study aims to detect anomalous patterns in the incidence of gastrointestinal disease in the (human) community; to target sampling; to test traditional diagnostic methods against rapid, modern, and sensitive molecular and genomic microbiology methods that identify and characterize responsible pathogens rapidly and more completely; and to determine the cost-effectiveness of rapid, modern, sensitive molecular and genomic microbiology methods. METHODS: Syndromic surveillance will be used to aid identification of anomalous patterns in microbiological events based on temporal associations, demographic similarities among patients and animals, and changes in trends in acute gastroenteritis cases using a point process statistical model. Stool samples will be obtained from patients' consulting GPs, to improve the timeliness of cluster detection and characterize the pathogens responsible, allowing health protection professionals to investigate and control outbreaks quickly, limiting their size and impact. The cost-effectiveness of the proposed system will be examined using formal cost-utility analysis to inform decisions on national implementation. RESULTS: The project commenced on April 1, 2013. Favorable approval was obtained from the Research Ethics Committee on June 15, 2015, and the first patient was recruited on October 13, 2015, with 1407 patients recruited and samples processed using traditional laboratory techniques as of March 2017. CONCLUSIONS: The overall aim of this study is to create a new One Health paradigm for detecting and investigating diarrhea and vomiting in the community in near-real time, shifting from passive human surveillance and management of laboratory-confirmed infection toward an integrated, interdisciplinary enhanced surveillance system including management of people with symptoms. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/13941.

Gastric Residual Volume Measurement in U.K. PICUs: A Survey of Practice.

OBJECTIVES: Despite little evidence, the practice of routine measurement of gastric residual volume to guide both the initiation and delivery of enteral feeding in PICUs is widespread internationally. In light of increased scrutiny of the evidence surrounding this practice, and as part of a trial feasibility study, we aimed to determine enteral feeding and gastric residual volume measurement practices in U.K. PICUs. DESIGN: An online survey to 27 U.K. PICUs. SETTING: U.K. PICUs. SUBJECTS: A clinical nurse, senior doctor, and dietician were invited to collaboratively complete one survey per PICU and send a copy of their unit guidelines on enteral feeding and gastric residual volume. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: Twenty-four of 27 units (89%) approached completed the survey. Twenty-three units (95.8%; 23/24) had written feeding guidelines, and 19 units (19/23; 83%) sent their guidelines for review. More units fed continuously (15/24; 62%) than intermittently (9/24; 37%) via the gastric route as their primary feeding method. All but one PICU routinely measured gastric residual volume, regardless of the method of feeding. Eighteen units had an agreed definition of feed tolerance, and all these included gastric residual volume. Gastric residual volume thresholds for feed tolerance were either volume based (mL/kg body weight) (11/21; 52%) or a percentage of the volume of feed administered (6/21; 29%). Yet only a third of units provided guidance about the technique of gastric residual volume measurement. CONCLUSIONS: Routine gastric residual volume measurement is part of standard practice in U.K. PICUs, with little guidance provided about the technique which may impact the accuracy of gastric residual volume. All PICUs that defined feed tolerance included gastric residual volume in the definition. This is important to know when proposing a standard practice arm of any future trial of no-routine gastric residual volume measurement in critically ill children.

Parents' prioritised outcomes for trials investigating treatments for paediatric severe infection: a qualitative synthesis.

OBJECTIVE: To identify parents' prioritised outcomes by combining qualitative findings from two trial feasibility studies of interventions for paediatric suspected severe infection. DESIGN: Qualitative synthesis combining parent interview data from the Fluids in Shock (FiSh) and Fever feasibility studies. Parents had experience of their child being admitted to a UK emergency department or intensive care unit with a suspected infection. PARTICIPANTS: n=: 85 parents. FiSh study: n=41 parents, 37 mothers, 4 fathers, 7 were bereaved. Fever study: n=44 parents, 33 mothers, 11 fathers, 7 were bereaved. RESULTS: In addition to survival, parents prioritised short-term outcomes including: organ and physiological functioning (eg, heart rate, breathing rate and temperature); their child looking and/or behaving more like their normal self; and length of time on treatments or mechanical support. Longer term prioritised outcomes included effects of illness on child health and development. We found that parents' prioritisation of outcomes was influenced by their experience of their child's illness, survival and the point at which they are asked about outcomes of importance in the course of their child's illness. CONCLUSIONS: Findings provide insight into parent prioritised outcomes to inform the design of future trials investigating treatments for paediatric suspected or proven severe infection as well as core outcome set development work.

Different temperature thresholds for antipyretic intervention in critically ill children with fever due to infection: the FEVER feasibility RCT.

BACKGROUND: Fever accelerates host immune system control of pathogens but at a high metabolic cost. The optimal approach to fever management and the optimal temperature thresholds used for treatment in critically ill children are unknown. OBJECTIVES: To determine the feasibility of conducting a definitive randomised controlled trial (RCT) to evaluate the clinical effectiveness and cost-effectiveness of different temperature thresholds for antipyretic management. DESIGN: A mixed-methods feasibility study comprising three linked studies - (1) a qualitative study exploring parent and clinician views, (2) an observational study of the epidemiology of fever in children with infection in paediatric intensive care units (PICUs) and (3) a pilot RCT with an integrated-perspectives study. SETTING: Participants were recruited from (1) four hospitals in England via social media (for the FEVER qualitative study), (2) 22 PICUs in the UK (for the FEVER observational study) and (3) four PICUs in England (for the FEVER pilot RCT). PARTICIPANTS: (1) Parents of children with relevant experience were recruited to the FEVER qualitative study, (2) patients who were unplanned admissions to PICUs were recruited to the FEVER observational study and (3) children admitted with infection requiring mechanical ventilation were recruited to the FEVER pilot RCT. Parents of children and clinicians involved in the pilot RCT. INTERVENTIONS: The FEVER qualitative study and the FEVER observational study had no interventions. In the FEVER pilot RCT, children were randomly allocated (1 : 1) using research without prior consent (RWPC) to permissive (39.5 °C) or restrictive (37.5 °C) temperature thresholds for antipyretics during their PICU stay while mechanically ventilated. MAIN OUTCOME MEASURES: (1) The acceptability of FEVER, RWPC and potential outcomes (in the FEVER qualitative study), (2) the size of the potentially eligible population and the temperature thresholds used (in the FEVER observational study) and (3) recruitment and retention rates, protocol adherence and separation between groups and distribution of potential outcomes (in the FEVER pilot RCT). RESULTS: In the FEVER qualitative study, 25 parents were interviewed and 56 clinicians took part in focus groups. Both the parents and the clinicians found the study acceptable. Clinicians raised concerns regarding temperature thresholds and not using paracetamol for pain/discomfort. In the FEVER observational study, 1853 children with unplanned admissions and infection were admitted to 22 PICUs between March and August 2017. The recruitment rate was 10.9 per site per month. The majority of critically ill children with a maximum temperature of > 37.5 °C received antipyretics. In the FEVER pilot RCT, 100 eligible patients were randomised between September and December 2017 at a recruitment rate of 11.1 per site per month. Consent was provided for 49 out of 51 participants in the restrictive temperature group, but only for 38 out of 49 participants in the permissive temperature group. A separation of 0.5 °C (95% confidence interval 0.2 °C to 0.8 °C) between groups was achieved. A high completeness of outcome measures was achieved. Sixty parents of 57 children took part in interviews and/or completed questionnaires and 98 clinicians took part in focus groups or completed a survey. Parents and clinicians found the pilot RCT and RWPC acceptable. Concerns about children being in pain/discomfort were cited as reasons for withdrawal and non-consent by parents and non-adherence to the protocol by clinicians. LIMITATIONS: Different recruitment periods for observational and pilot studies may not fully reflect the population that is eligible for a definitive RCT. CONCLUSIONS: The results identified barriers to delivering the definitive FEVER RCT, including acceptability of the permissive temperature threshold. The findings also provided insight into how these barriers may be overcome, such as by limiting the patient inclusion criteria to invasive ventilation only and by improved site training. A definitive FEVER RCT using a modified protocol should be conducted, but further work is required to agree important outcome measures for clinical trials among critically ill children. TRIAL REGISTRATION: The FEVER observational study is registered as NCT03028818 and the FEVER pilot RCT is registered as Current Controlled Trials ISRCTN16022198. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 5. See the NIHR Journals Library website for further project information.