Influenza is a major global health concern, responsible for up to 650 000 respiratory-related deaths annually. Although influenza is often perceived as mild in healthy adults, it can cause severe outcomes in high-risk groups, such as older adults, young children, pregnant women and those with underlying medical conditions. Various clinical, sociodemographic and environmental factors influence the progression to severe outcomes, whereas resilience factors, such as vaccination, may reduce risks. Despite growing research, the evidence base regarding risk and resilience is spread across many different aspects of the literature. This umbrella review will synthesise evidence from existing systematic reviews and meta-analyses to identify key risk and resilience factors associated with the progression of influenza to severe outcomes in the general population.

This umbrella review follows the Joanna Briggs Institute (JBI) and Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. We will include systematic reviews and meta-analyses reporting host-related risk or resilience factors for severe influenza outcomes. Four databases (EMBASE, Scopus, Medline and CINAHL) will be searched for English-language publications. Study quality will be assessed using AMSTAR 2, and the body of evidence will be evaluated using Grading of Recommendations Assessment, Development and Evaluation. Due to heterogeneity, findings will be analysed narratively. Risk and resilience factors will be grouped into demographic, clinical, behavioural, social and psychological domains.

No ethical approval is required. The completed review will be shared through peer-reviewed journals and conference presentations.

CRD420250644475.

The use of invasive life support in patients with a prolonged critical illness clearly saves lives but carries substantial risks, including intensive care unit-acquired weakness (ICUAW) and long-term disability. Early mobilisation might improve outcomes, yet the evidence is conflicting and complicated by the lack of a responsive outcome measurement to detect change in critically ill patients’ physical function and activity. The Chelsea Critical Care Physical Assessment tool (CPAx) is a valid and reliable instrument for patients at risk of ICUAW. However, its ability to measure change over time (responsiveness) and the minimal clinically important difference (MCID) have not yet been rigorously investigated.

The primary objective of this prospective, international, multicentre, longitudinal cohort study is to investigate responsiveness and to establish the MCID of the CPAx during the ‘intensive care unit (ICU) period’, from ICU baseline to ICU discharge, and ‘hospital period’, from ICU to hospital discharge. Adults with any critical illness who are mechanically ventilated for at least 72 hours, expected to remain in ICU (≥48 hours) and being treated by a physiotherapist are eligible for study inclusion. Functional measurements, including the CPAx and a global rating of change (GRC) scale, will be collected during routine physiotherapy. Responsiveness will be evaluated primarily using the GRC as an anchor to distinguish changed from unchanged/deteriorated patients (criterion validity). As such, the magnitude of change will be analysed with receiver operating characteristics. Additionally, construct validity will be explored with correlation coefficients and effect sizes to confirm/reject a priori formulated hypotheses. MCID will be investigated with anchor-based and distribution-based methods. We plan to recruit 120 patients across three sites in Australia and Switzerland.

Ethical approval has been obtained from each local ethics committee (Canton of Bern, Switzerland (2024-00346), Monash Health, Australia (HREC/106143/MonH-2024-438474(v3)), the Alfred, Australia (490/24)). The results will be disseminated through international/national conferences, peer-reviewed journals and social media. The high quality, rigorous testing of the CPAx could benefit researchers, clinicians and patients.

NCT06419699.

School environments that encourage children to be physically active can embed lifelong positive health behaviours and contribute towards reducing health inequalities. The Health and Activity of Pupils in the Primary Years (HAPPY) study aims to: (1) explore the extent to which the WHO criteria for creating active school environments are implemented by primary schools and (2) examine associations between active school environments and children’s physical activity, mental health and educational performance.

The HAPPY study is a quasi-experimental study comprising: (1) a survey of state-funded Greater London primary schools to identify implementation of the WHO’s six criteria and (2) a cross-sectional study to examine associations between schools’ active environment score (derived from the school survey) and pupils’ physical activity, mental health and educational performance. For our cross-sectional study, we will recruit up to 1000 year-three children (aged 7–8 years). Our primary outcome is accelerometer (GENEActiv) assessed physical activity, our secondary outcomes are parent-reported child mental health (Strengths and Difficulties Questionnaire) and teacher-reported educational performance (age-related expectations). Using multilevel mixed-effects regression models, we will examine associations between the active environment score and physical activity. Physical activity will be included as a measure of acceleration and also different intensities (light, moderate, vigorous). We will repeat this analysis to examine associations between the active environment score and mental health and educational performance. We will adjust for school characteristics and area-level deprivation and include pupil characteristics (eg, sex, ethnic group) as covariates. Clustering at the school level will be included as a random effect.

Ethical approval has been obtained from Imperial College Research Ethics Committee (ref: 6800895). Findings will be disseminated through a summary report to all participating schools, peer-reviewed publications, presentations at national and international conferences and National Institute for Health and Care Research policy briefings.