Cortical processing of flexible and context-dependent sensorimotor sequences.

The brain generates complex sequences of movements that can be flexibly configured based on behavioural context or real-time sensory feedback1, but how this occurs is not fully understood. Here we developed a 'sequence licking' task in which mice directed their tongue to a target that moved through a series of locations. Mice could rapidly branch the sequence online based on tactile feedback. Closed-loop optogenetics and electrophysiology revealed that the tongue and jaw regions of the primary somatosensory (S1TJ) and motor (M1TJ) cortices2 encoded and controlled tongue kinematics at the level of individual licks. By contrast, the tongue 'premotor' (anterolateral motor) cortex3-10 encoded latent variables including intended lick angle, sequence identity and progress towards the reward that marked successful sequence execution. Movement-nonspecific sequence branching signals occurred in the anterolateral motor cortex and M1TJ. Our results reveal a set of key cortical areas for flexible and context-informed sequence generation.

A Genome-Wide Association Study of Respiratory Syncytial Virus Infection Severity in Infants.

BACKGROUND: Respiratory syncytial virus (RSV) is a significant cause of infant morbidity and mortality worldwide. Most children experience at least one 1 RSV infection by the age of two 2 years, but not all develop severe disease. However, the understanding of genetic risk factors for severe RSV is incomplete. Consequently, we conducted a genome-wide association study of RSV severity. METHODS: Disease severity was assessed by the ReSVinet scale, in a cohort of 251 infants aged 1 week to 1 year. Genotyping data were collected from multiple European study sites as part of the RESCEU Consortium. Linear regression models were used to assess the impact of genotype on RSV severity and gene expression as measured by microarray. RESULTS: While no SNPs reached the genome-wide statistical significance threshold (P < 5 × 10-8), we identified 816 candidate SNPs with a P-value of <1 × 10-4. Functional annotation of candidate SNPs highlighted genes relevant to neutrophil trafficking and cytoskeletal functions, including LSP1 and RAB27A. Moreover, SNPs within the RAB27A locus significantly altered gene expression (false discovery rate, FDR P < .05). CONCLUSIONS: These findings may provide insights into genetic mechanisms driving severe RSV infection, offering biologically relevant information for future investigations.

Exploring Factors Associated With Accelerometer Validity Among Ethnically Diverse Toddlers.

PURPOSE: Studying physical activity in toddlers using accelerometers is challenging due to noncompliance with wear time (WT) and activity log (AL) instructions. The aims of this study are to examine relationships between WT and AL completion and (1) demographic and socioeconomic variables, (2) parenting style, and (3) whether sedentary time differs by AL completion. METHODS: Secondary analysis was performed using baseline data from a community wellness program randomized controlled trial for parents with toddlers (12-35 mo). Parents had toddlers wear ActiGraph wGT3x accelerometers and completed ALs. Valid days included ≥600-minute WT. Analysis of variance and chi-square analyses were used. RESULTS: The sample (n = 50) comprised racial and ethnically diverse toddlers (mean age = 27 mo, 58% male) and parents (mean age = 31.7 y, 84% female). Twenty-eight families (56%) returned valid accelerometer data with ALs. Participants in relationships were more likely to complete ALs (P < .05). Toddler sedentary time did not differ between those with ALs and those without. CONCLUSIONS: We found varied compliance with WT instructions and AL completion. Returned AL quality was poor, presenting challenges in correctly characterizing low-activity counts to improve internal validity of WT and physical activity measures. Support from marital partners may be important for adherence to study protocols.

Imaging of cerebrovascular complications from blunt skull base trauma.

Cerebrovascular complications from blunt trauma to the skull base, though rare, can lead to potentially devastating outcomes, emphasizing the importance of timely diagnosis and management. Due to the insidious clinical presentation, subtle nature of imaging findings, and complex anatomy of the skull base, diagnosing cerebrovascular injuries and their complications poses considerable challenges. This article offers a comprehensive review of skull base anatomy and pathophysiology pertinent to recognizing cerebrovascular injuries and their complications, up-to-date screening criteria and imaging techniques for assessing these injuries, and a case-based review of the spectrum of cerebrovascular complications arising from skull base trauma. This review will enhance understanding of cerebrovascular injuries and their complications from blunt skull base trauma to facilitate diagnosis and timely treatment.

Recommendations on the use of item libraries for patient-reported outcome measurement in oncology trials: findings from an international, multidisciplinary working group.

The use of item libraries for patient-reported outcome (PRO) measurement in oncology allows for the customisation of PRO assessment to measure key health-related quality of life concepts of relevance to the target population and intervention. However, no high-level recommendations exist to guide users on the design and implementation of these customised PRO measures (item lists) across different PRO measurement systems. To address this issue, a working group was set up, including international stakeholders (academic, independent, industry, health technology assessment, regulatory, and patient advocacy), with the goal of creating recommendations for the use of item libraries in oncology trials. A scoping review was carried out to identify relevant publications and highlight any gaps. Stakeholders commented on the available guidance for each research question, proposed recommendations on how to address gaps in the literature, and came to an agreement using discussion-based methods. Nine primary research questions were identified that formed the scope and structure of the recommendations on how to select items and implement item lists created from item libraries. These recommendations address methods to drive item selection, plan the structure and analysis of item lists, and facilitate their use in conjunction with other measures. The findings resulted in high-level, instrument-agnostic recommendations on the use of item-library-derived item lists in oncology trials.

Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints in Cancer Clinical Trials-Innovative Medicines Initiative (SISAQOL-IMI): stakeholder views, objectives, and procedures.

Patient-reported outcomes (PROs), such as symptoms, functioning, and other health-related quality-of-life concepts are gaining a more prominent role in the benefit-risk assessment of cancer therapies. However, varying ways of analysing, presenting, and interpreting PRO data could lead to erroneous and inconsistent decisions on the part of stakeholders, adversely affecting patient care and outcomes. The Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints in Cancer Clinical Trials-Innovative Medicines Initiative (SISAQOL-IMI) Consortium builds on the existing SISAQOL work to establish recommendations on design, analysis, presentation, and interpretation for PRO data in cancer clinical trials, with an expanded set of topics, including more in-depth recommendations for randomised controlled trials and single-arm studies, and for defining clinically meaningful change. This Policy Review presents international stakeholder views on the need for SISAQOL-IMI, the agreed on and prioritised set of PRO objectives, and a roadmap to ensure that international consensus recommendations are achieved.

The Importance of Accounting for Movement When Relating Neuronal Activity to Sensory and Cognitive Processes.

A surprising finding of recent studies in mouse is the dominance of widespread movement-related activity throughout the brain, including in early sensory areas. In awake subjects, failing to account for movement risks misattributing movement-related activity to other (e.g., sensory or cognitive) processes. In this article, we (1) review task designs for separating task-related and movement-related activity, (2) review three "case studies" in which not considering movement would have resulted in critically different interpretations of neuronal function, and (3) discuss functional couplings that may prevent us from ever fully isolating sensory, motor, and cognitive-related activity. Our main thesis is that neural signals related to movement are ubiquitous, and therefore ought to be considered first and foremost when attempting to correlate neuronal activity with task-related processes.

Early transcriptional responses to human enteric fever challenge.

Enteric fever, caused by oral infection with typhoidal Salmonella serovars, presents as a non-specific febrile illness preceded by an incubation period of 5 days or more. The enteric fever human challenge model provides a unique opportunity to investigate the innate immune response during this incubation period, and how this response is altered by vaccination with the Vi polysaccharide or conjugate vaccine. We find that on the same day as ingestion of typhoidal Salmonella, there is already evidence of an immune response, with 199 genes upregulated in the peripheral blood transcriptome 12 hours post-challenge (false discovery rate <0.05). Gene sets relating to neutrophils, monocytes, and innate immunity were over-represented (false discovery rate <0.05). Estimating cell proportions from gene expression data suggested a possible increase in activated monocytes 12 hours post-challenge (P = 0.036, paired Wilcoxon signed-rank test). Furthermore, plasma TNF-α rose following exposure (P = 0.011, paired Wilcoxon signed-rank test). There were no significant differences in gene expression (false discovery rate <0.05) in the 12 hours response between those who did and did not subsequently develop clinical or blood culture confirmed enteric fever or between vaccination groups. Together, these results demonstrate early perturbation of the peripheral blood transcriptome after enteric fever challenge and provide initial insight into early mechanisms of protection.

RNA2HLA: HLA-based quality control of RNA-seq datasets.

RNA-sequencing (RNA-seq) is a widely used approach for accessing the transcriptome in biomedical research. Studies frequently include multiple samples taken from the same individual at various time points or under different conditions, correct assignment of those samples to each particular participant is evidently of great importance. Here, we propose taking advantage of typing the highly polymorphic genes from the human leukocyte antigen (HLA) complex in order to verify the correct allocation of RNA-seq samples to individuals. We introduce RNA2HLA, a novel quality control (QC) tool for performing study-wide HLA-typing for RNA-seq data and thereby identifying the samples from the common source. RNA2HLA allows precise allocation and grouping of RNA samples based on their HLA types. Strikingly, RNA2HLA revealed wrongly assigned samples from publicly available datasets and thereby demonstrated the importance of this tool for the quality control of RNA-seq studies. In addition, our tool successfully extracts HLA alleles in four-digital resolution and can be used to perform massive HLA-typing from RNA-seq based studies, which will serve multiple research purposes beyond sample QC.

Clinical and Viral Factors Associated With Disease Severity and Subsequent Wheezing in Infants With Respiratory Syncytial Virus Infection.

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in infants and young children worldwide. Here we evaluated host demographic and viral factors associated with RSV disease severity in 325 RSV-infected infants under 1 year of age from 3 European countries during 2017-2020. Younger infants had a higher clinical severity (ReSViNET) score and were more likely to require hospitalization, intensive care, respiratory support, and/or mechanical ventilation than older infants (<3 months vs 3 to <6 months and 3 to <6 months vs ≥6 months). Older age (≥6 months vs <3 months), higher viral load, and RSV-A were associated with a greater probability of fever. RSV-A and RSV-B caused similar disease severity and had similar viral dynamics. Infants with a more severe RSV infection, demonstrated by having a higher ReSViNET score, fever, and requiring hospitalization and intensive care, were more likely to have developed subsequent wheezing at 1 year of age. CLINICAL TRIALS REGISTRATION: NCT03756766.

Immune status does not independently influence cutaneous squamous cell carcinoma metastasis and death when stratified by tumor stage: A dual-center retrospective cohort analysis of primary N0 disease.

BACKGROUND: Although immunocompromised patients have a higher risk of developing cutaneous squamous cell carcinomas, it is unknown whether immune status is an independent risk factor for poor outcomes. OBJECTIVE: To compare cutaneous squamous cell carcinoma outcomes in immunocompromised and immunocompetent patients when controlling for T-stage. METHODS: We performed a retrospective cohort study at 2 tertiary care centers, examining 989 primary tumors from 814 immunocompromised patients (solid organ transplant: 259 [31.7%], chronic lymphocytic leukemia: 113 [13.9%]) and 6608 tumors from 4198 immunocompetent patients. Our primary outcome was the composite of disease-specific death or tumor metastasis ("poor outcomes"). RESULTS: Immunocompromised patients had 50% more high T-stage tumors (ie, Brigham and Women's Hospital stage T2b and T3), than immunocompetent patients (3.3% vs 4.9%, respectively; P < .001). Significant predictors of poor outcomes included tumor stage (sub hazards ratio [SHR], 14.8 for high T-stage tumors; 95% confidence interval [CI], 8.0-27.6; P < .001) and male sex (SHR, 2.3; 95% CI, 1.4-3.8; P = .002). Immune status was not a significant predictor (SHR, 1.04; 95% CI, 0.69-1.6; P = .85). LIMITATIONS: This study is retrospective. CONCLUSION: Although immunocompromised patients had 50% more high T-stage tumors than immunocompetent patients, immunocompromised patients had a similar chance of metastasis and disease-specific death when adjusting for T-stage in our cohort of primary tumors.

Engaging in advocacy during medical training: assessing the impact of a virtual COVID-19-focused state advocacy day.

PURPOSE: The physician voice is crucial to shaping health policy and public health guidelines, particularly during COVID-19. However, there are gaps in health policy and advocacy education within graduate medical education. This study sought to characterise the impact of a virtual COVID-19 focused advocacy day among medical trainees in Massachusetts. STUDY DESIGN: The half-day event featured speakers drawn from government relations experts, physician advocates, and state and federal legislators as well as breakout discussions among attendees. A 25-question Redcap survey and list of resources/opportunities for continued advocacy was administered to all participants at event's conclusion on 19 May 2020. RESULTS: There were 60 responses from 141 participants (43% response rate). One-third reported no prior formal health policy instruction, and over half reported getting information from news publications, social media and peers. 58% believed physician involvement in advocacy to be 'extremely important' prior to COVID-19; 83% believed the same after onset of COVID-19 (p<0.0001). The most common barriers to advocacy engagement were lack of time and knowledge. Most attendees felt participation increased their knowledge and likelihood to engage in the COVID-19 response, imparted useful skills/knowledge for continued advocacy, increased their interest in future similar events, and that such events should be available to all trainees. CONCLUSIONS: Trainees recognise the importance of health policy and advocacy and value opportunities to gain the necessary skills/knowledge to effect tangible change. Virtual advocacy days can be replicated nationwide to help trainees learn about advocacy efforts and find their legislative voices during COVID-19 and beyond.

Guidelines for cellular and molecular pathology content in clinical trial protocols: the SPIRIT-Path extension.

The 2013 SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) Statement provides evidence-based recommendations for the minimum content to be included in a clinical trial protocol. Assessment of biospecimens is often required for trial eligibility or as part of an outcome evaluation, and precision molecular approaches are increasingly used in trial design. However, cellular and molecular pathology practices within trials have not been codified or formalised. We developed international consensus reporting guidelines for cellular and molecular pathology content in clinical trial protocols (the SPIRIT-Path extension) using an international Delphi process, which assesses candidate items generated from a previous systematic review, followed by an expert consensus meeting. 74 individuals from five continents responded, including clinicians, statisticians, laboratory scientists, patient advocates, funders, industry representatives, journal editors, and regulators. The SPIRIT-Path guidelines recommend 14 additional items (seven extensions to the SPIRIT checklist and seven elaborations) that should be addressed in trial protocols containing pathology content, alongside the SPIRIT 2013 Statement items. SPIRIT-Path recommends that protocols should document the individuals, processes, and standards for all cellular and molecular pathology components of the trial, including all stages of the specimen pathway and any digital pathology methods, with specific consideration of the value of trial data and biological tissues for additional translational studies.

Distinct patterns of whole blood transcriptional responses are induced in mice following immunisation with adenoviral and poxviral vector vaccines encoding the same antigen.

BACKGROUND: Viral vectors, including adenovirus (Ad) and modified vaccinia Ankara (MVA), have gained increasing attention as vaccine platforms in recent years due to their capacity to express antigens from a wide array of pathogens, their rapid induction of humoral and cellular protective immune responses, and their relatively low production costs. In particular, the chimpanzee Ad vector, ChAdOx1, has taken centre stage as a leading COVID-19 vaccine candidate. However, despite mounting data, both clinical and pre-clinical, demonstrating effective induction of adaptive immune responses, the innate immune signals that precede the protective responses that make these vectors attractive vaccine platforms remain poorly understood. RESULTS: In this study, a mouse immunisation model was used to evaluate whole blood gene expression changes 24 h after either a single dose or heterologous prime-boost regimen of an Ad and/or MVA vaccine. We demonstrate through comparative analysis of Ad vectors encoding different antigens that a transgene product-specific gene signature can be discerned from the vector-induced transcriptional response. Expression of genes involved in TLR2 stimulation and γδ T cell and natural killer cell activation were induced after a single dose of Ad, while MVA led to greater expression of type I interferon genes. The order of prime-boost combinations was found to influence the magnitude of the gene expression changes, with MVA/Ad eliciting greater transcriptional perturbation than Ad/MVA. Contrasting the two regimens revealed significant enrichment of epigenetic regulation pathways and augmented expression of MHC class I and II molecules associated with MVA/Ad. CONCLUSION: These data demonstrate that the order in which vaccines from heterologous prime-boost regimens are administered leads to distinct transcriptional responses and may shape the immune response induced by such combinations. The characterisation of early vaccine-induce responses strengthens our understanding of viral vector vaccine mechanisms of action ahead of their characterisation in human clinical trials and are a valuable resource to inform the pre-clinical design of appropriate vaccine constructs for emerging infectious diseases.

A staged approach to address youth unresponsive to initial obesity intervention: a randomized clinical trial.

BACKGROUND/OBJECTIVE: Maintenance interventions inherently require BMI improvement to maintain. This overlooks individuals initially unresponsive to obesity interventions. Staged pediatric clinical treatment guidelines were adapted to the school setting to develop an escalated treatment option for individuals initially unresponsive. This staged randomized controlled trial examined differences between escalated treatment (Take CHARGE!) and a maintenance program (PE Planners). Take CHARGE was hypothesized to have greater improvements in BMI as a percentage of the 95th BMI Percentile (%BMIp95) than PE Planners. SUBJECTS/METHODS: From 2018 to 2020, 171 middle and high schoolers (BMI Percentile ≥ 85) were recruited from a Houston school district to participate in a staged obesity intervention in their physical education (PE) class. After receiving a semester-long intensive lifestyle intervention (ILI) with established efficacy, all participants were randomized to Take CHARGE (n = 85) or PE Planners (n = 86). Take CHARGE escalated the behavioral treatment of obesity received in ILI with more frequent individual sessions, additional opportunities for parental and school staff involvement, and increased mentorship from trained college students. PE Planners allowed participants to decide how they wanted to be active in PE class. Mixed linear modeling examined %BMIp95 overtime between groups. This trial was registered at ClinicalTrials.gov (#NCT04362280). RESULTS: Participants were 13.63 ± 1.32 years old; 59% were female, and 85% were Hispanic. Among those initially unresponsive to ILI, Take CHARGE had significantly greater decreases in %BMIp95 than PE Planners (ß = -0.01, p < 0.01). Conversely, among those initially responsive, Take CHARGE had significantly smaller decreases in %BMIp95 than PE Planners (ß = 0.02, p < 0.05). Intention-to-treat analysis had similar results. CONCLUSIONS: Participant outcomes in semester two differed based on initial response. Individuals responsive to initial intervention were most likely to benefit from a maintenance intervention and those initially unresponsive benefited more from escalated treatment. This indicates the need for staged intervention protocols to better address obesity in the school setting.

Gene expression profiling reveals insights into infant immunological and febrile responses to group B meningococcal vaccine.

Neisseria meningitidis is a major cause of meningitis and septicaemia. A MenB vaccine (4CMenB) was licensed by the European Medicines Agency in January 2013. Here we describe the blood transcriptome and proteome following infant immunisations with or without concomitant 4CMenB, to gain insight into the molecular mechanisms underlying post-vaccination reactogenicity and immunogenicity. Infants were randomised to receive control immunisations (PCV13 and DTaP-IPV-Hib) with or without 4CMenB at 2 and 4 months of age. Blood gene expression and plasma proteins were measured prior to, then 4 h, 24 h, 3 days or 7 days post-vaccination. 4CMenB vaccination was associated with increased expression of ENTPD7 and increased concentrations of 4 plasma proteins: CRP, G-CSF, IL-1RA and IL-6. Post-vaccination fever was associated with increased expression of SELL, involved in neutrophil recruitment. A murine model dissecting the vaccine components found the concomitant regimen to be associated with increased gene perturbation compared with 4CMenB vaccine alone with enhancement of pathways such as interleukin-3, -5 and GM-CSF signalling. Finally, we present transcriptomic profiles predictive of immunological and febrile responses following 4CMenB vaccine.

Organizational Characteristics and Readiness for Tobacco-Free Workplace Program Implementation Moderates Changes in Clinician's Delivery of Smoking Interventions within Behavioral Health Treatment Clinics.

BACKGROUND: Smoking is elevated amongst individuals with behavioral health disorders, but not commonly addressed. Taking Texas Tobacco Free is an evidence-based, tobacco-free workplace program that addresses this, in-part, by providing clinician training to treat tobacco use in local mental health authorities (LMHAs). This study examined organizational moderators of change in intervention delivery from pre- to post-program implementation. METHODS: LMHA leaders completed the Organizational Readiness for Implementing Change (ORIC) and provided organization demographics pre-implementation. Clinicians (N = 1237) were anonymously surveyed about their consistent use of the 5As (Asking about smoking; Advising clientele to quit; Assessing willingness to quit; Assisting them to quit; Arranging follow-up) pre- and post-program implementation. Adjusted generalized linear mixed models were used for analyses (responses nested within LMHAs), with interaction terms used to assess moderation effects. RESULTS: Clinician delivery of 5As increased pre- to post-implementation (p < .001). LMHAs with fewer employees (ref = ≤300) demonstrated greater increases in Asking, Assessing, and Assisting over time. LMHAs with fewer patients (ref = ≤10 000) evinced greater changes in Asking over time. Less initial ORIC Change Efficacy, Change Commitment, and Task Knowledge were each associated with greater pre- to post-implementation changes in Asking. Less initial Task Knowledge was associated with greater increases in Advising, Assessing, and Assisting. Finally, less initial Resource Availability was associated with greater increases in Assisting (all moderation term ps < .025). CONCLUSION: The smallest and least ready LMHAs showed the largest gains in tobacco cessation intervention delivery; thus, low initial readiness was not a barrier for program implementation, particularly when efficacy-building training and resources are provided. IMPLICATIONS: This study examined organizational moderators of increases in tobacco cessation treatment delivery over time following the implementation of a comprehensive tobacco-free workplace program within 20 of 39 LMHAs across Texas (hundreds of clinics; servicing >50% of the state) from 2013 to 2018. Overall, LMHAs with fewer employees and patients, and that demonstrated the least initial readiness for change, evinced greater gains in intervention delivery. Findings add to dissemination and implementation science by supporting that low initial readiness was not a barrier for this aspect of tobacco-free workplace program implementation when resources and clinician training sessions were provided.

Psychometric properties of the Food Environment Assessment Survey Tool (FEAST) in people with mobility impairment.

OBJECTIVE: Approximately one in ten adults under the age of 65 in the USA has a mobility impairing disability. People with mobility impairment generally have poorer dietary habits contributing to obesity and related negative health outcomes. This article presents the psychometric properties of the Food Environment Assessment Survey Tool (FEAST) instrument that measures barriers to accessing healthy food from the perspective of people with mobility impairment (PMI). DESIGN: The current study presents cross-sectional data from two sequential independent surveys. SETTING: Surveys were administered online to a national sample of PMI. PARTICIPANTS: Participants represented PMI living throughout the USA. The pilot FEAST survey involved 681 participants and was used to shape the final instrument; 25 % completed a retest survey. After following empirically and theoretically guided item reduction strategies, the final FEAST instrument was administered to a separate sample of 304 PMI. RESULTS: The final twenty-seven-item FEAST instrument includes items measuring Neighbourhood Environment, Home Environment, Personal Control and Access to Support (Having Help, Food Delivery Services, Parking/Transportation). The final four scales had acceptable intra-class correlations, indicating that the scales could be used as reliable measures of the hypothesised constructs in future studies. CONCLUSIONS: The FEAST instrument is the first of its kind developed to assess the food environment from the perspective of PMI themselves. Future studies would benefit from using this measure in research and practice to help guide the development of policy aimed at improving access to healthy food and promoting healthy eating in community-dwelling PMI.

Di-chromatic interpolation of magnetic resonance metabolic images.

OBJECTIVE: Magnetic resonance imaging with hyperpolarized contrast agents can provide unprecedented in vivo measurements of metabolism, but yields images that are lower resolution than that achieved with proton anatomical imaging. In order to spatially localize the metabolic activity, the metabolic image must be interpolated to the size of the proton image. The most common methods for choosing the unknown values rely exclusively on values of the original uninterpolated image. METHODS: In this work, we present an alternative method that uses the higher-resolution proton image to provide additional spatial structure. The interpolated image is the result of a convex optimization algorithm which is solved with the fast iterative shrinkage threshold algorithm (FISTA). RESULTS: Results are shown with images of hyperpolarized pyruvate, lactate, and bicarbonate using data of the heart and brain from healthy human volunteers, a healthy porcine heart, and a human with prostate cancer.

BEFRIENding for Depression, Anxiety and Social support in older adults living in Australian residential aged care facilities (BEFRIENDAS): randomised controlled trial protocol.

BACKGROUND: This protocol describes an ongoing study of the impact of befriending on depression, anxiety and loneliness in older people living in residential aged care facilities in Australia. While systematic reviews of befriending have indicated positive benefits of befriending for people in a range of ages and settings, there have been no randomised controlled trials (RCTs) of befriending for older people living in residential aged care with depression and no studies of the cost effectiveness of befriending in residential aged care facilities (RACFs) in Australia. METHODS AND ANALYSIS: We are conducting a single blind pragmatic RCT comparing two groups of older people living in RACFs, one receiving an intervention consisting of weekly befriending for 4 months from a trained volunteer and the other receiving treatment as usual. Participants undergo eligibility screening for depression (GDS-15 ≥ 4) and cognitive impairment (GPCog ≥ 4) and assessments at three measurement time points: baseline prior to randomisation, 2 months post-baseline and 4 months post-baseline. The primary outcome measure is depression, and secondary outcome measures are anxiety, loneliness, social isolation and quality of life. The economic evaluation will take the form of a cost-utility analysis based on the outcome of quality of life. The primary and secondary outcomes will be analysed using negative binomial and logistic regressions utilizing the Generalised Estimating Equations approach. DISCUSSION: To our knowledge, this is the first RCT evaluating the effectiveness of befriending on older people with depression living in residential aged care. It is expected that the befriending intervention will reduce the severity of depression symptoms experienced by older people living in residential aged care. If the intervention proves effective it may be incorporated into volunteer training programs and adopted as a way of supporting older people's mental health. TRIAL REGISTRATION: Trial registered with the Australian and New Zealand Clinical Trial Registry (ANZCTR) Number: ACTRN12619000676112 , registered 06/05/2019 - retrospectively registered.