Reliability of multi-site UK Biobank MRI brain phenotypes for the assessment of neuropsychiatric complications of SARS-CoV-2 infection: The COVID-CNS travelling heads study.

INTRODUCTION: Magnetic resonance imaging (MRI) of the brain could be a key diagnostic and research tool for understanding the neuropsychiatric complications of COVID-19. For maximum impact, multi-modal MRI protocols will be needed to measure the effects of SARS-CoV-2 infection on the brain by diverse potentially pathogenic mechanisms, and with high reliability across multiple sites and scanner manufacturers. Here we describe the development of such a protocol, based upon the UK Biobank, and its validation with a travelling heads study. A multi-modal brain MRI protocol comprising sequences for T1-weighted MRI, T2-FLAIR, diffusion MRI (dMRI), resting-state functional MRI (fMRI), susceptibility-weighted imaging (swMRI), and arterial spin labelling (ASL), was defined in close approximation to prior UK Biobank (UKB) and C-MORE protocols for Siemens 3T systems. We iteratively defined a comparable set of sequences for General Electric (GE) 3T systems. To assess multi-site feasibility and between-site variability of this protocol, N = 8 healthy participants were each scanned at 4 UK sites: 3 using Siemens PRISMA scanners (Cambridge, Liverpool, Oxford) and 1 using a GE scanner (King's College London). Over 2,000 Imaging Derived Phenotypes (IDPs), measuring both data quality and regional image properties of interest, were automatically estimated by customised UKB image processing pipelines (S2 File). Components of variance and intra-class correlations (ICCs) were estimated for each IDP by linear mixed effects models and benchmarked by comparison to repeated measurements of the same IDPs from UKB participants. Intra-class correlations for many IDPs indicated good-to-excellent between-site reliability. Considering only data from the Siemens sites, between-site reliability generally matched the high levels of test-retest reliability of the same IDPs estimated in repeated, within-site, within-subject scans from UK Biobank. Inclusion of the GE site resulted in good-to-excellent reliability for many IDPs, although there were significant between-site differences in mean and scaling, and reduced ICCs, for some classes of IDP, especially T1 contrast and some dMRI-derived measures. We also identified high reliability of quantitative susceptibility mapping (QSM) IDPs derived from swMRI images, multi-network ICA-based IDPs from resting-state fMRI, and olfactory bulb structure IDPs from T1, T2-FLAIR and dMRI data. CONCLUSION: These results give confidence that large, multi-site MRI datasets can be collected reliably at different sites across the diverse range of MRI modalities and IDPs that could be mechanistically informative in COVID brain research. We discuss limitations of the study and strategies for further harmonisation of data collected from sites using scanners supplied by different manufacturers. These acquisition and analysis protocols are now in use for MRI assessments of post-COVID patients (N = 700) as part of the ongoing COVID-CNS study.

Prevalence of Frailty in Older Community-Dwelling Tanzanians According to Comprehensive Geriatric Assessment.

OBJECTIVES: To investigate the prevalence of frailty using a Comprehensive Geriatric Assessment (CGA) in older community-dwelling adults living in rural northern Tanzania. DESIGN: Cross-sectional survey. SETTING: Five randomly selected villages in Hai District, Kilimanjaro region, Tanzania. PARTICIPANTS: All adults aged 60 and older living in the selected villages were eligible to participate, including older adults with cognitive impairment provided a close relative was able to assent on their behalf. All participants were community dwelling because institutionalization is very rare. MEASUREMENTS: Participants were screened using a short frailty screening tool, the Brief Frailty Instrument for Tanzania (B-FIT), comprising an abbreviated test of cognitive function and the Barthel Index, which assesses functional independence. Based on B-FIT score, a frailty-weighted, stratified sample was selected for in-depth assessment using CGA and characterized as frail or not frail. RESULTS: Two hundred thirty-six CGAs were performed in 1,207 people screened, 91 of whom were deemed frail. After adjusting for stratification, the prevalence of frailty was 19.1% (95% confidence interval=15.2-23.1). CONCLUSION: This is the first study in sub-Saharan Africa to report the prevalence of frailty in community-dwelling older adults according to a CGA. The strengths of reporting frailty according to a CGA include the ability to consider likely medical diagnoses based on clinical assessment and to assess individuals' social circumstances and environment.

Widening interest, widening participation: factors influencing school students' aspirations to study medicine.

BACKGROUND: Under-representation of some socio-economic groups in medicine is rooted in under-representation of those groups in applications to medical school. This study aimed to explore what may deter school-age children from applying to study medicine. METHODS: Workshops were undertaken with school students aged 16-17 years ('Year 12', n = 122 across three workshops) and 13-14 years ('Year 9', n = 295 across three workshops). Workshops used a variety of methods to identify and discuss participants' perceptions of medicine, medical school and the application process. Year 12 workshops focused on applications and medical school, while Year 9 took a broader approach reflecting their relative distance from applying. Subsequent workshops were informed by the findings of earlier ones. RESULTS: The main finding was that potential applicants had limited knowledge about medicine and medical school in several areas. Older students would benefit from accessible information about medical degrees and application processes, access to work experience opportunities and personal contact with medical students and junior doctors, particularly those from a similar background. Younger students demonstrated a lack of awareness of the breadth of medical careers and a limited understanding of what medicine encompasses. Many Year 9 students were attracted by elements of practice which they did not associate with medicine, such as 'talking to people with mental health problems'. An exercise addressing this elicited an increase in their interest in medicine. These issues were identified by participants as being more marked for those without knowledgeable support at home or school. It was apparent that school teachers may not be equipped to fill these knowledge gaps. CONCLUSION: Gaps in knowledge and support may reflect the importance of 'social capital' in facilitating access to medical school. Medical schools could act as hubs to introduce students to resources which are essential for widening participation. Outreach and support to schools may ensure that fundamental knowledge gaps are equitably addressed for all prospective applicants. More generally, a focus on medicine which under-emphasises aspects of medical practice involving communication may deter some students and have longer term impact on recruitment to careers including general practice and psychiatry.