Intra-individual reaction time variability in sustained attention

PhD ThesisBACKGROUND: Sustained attention, assessed using the Continuous Performance Test (CPT), is impaired in ‘normal’ ageing and, to a greater degree, in a number of clinical disorders. There are many variants of the CPT, each with different task parameters (e.g., target frequency), and theoretical cognitive demands (e.g., executive functioning). It is unclear how the associated cognitive load of CPTs contributes to measures of attentional impairment, such as intra-individual variability (IIV) in reaction time (RT). There is potential clinical utility in measures of IIV, due to its relationship with increasing age, and brain white matter. Variability can be modelled using the ex-Gaussian distribution, and consists of three parameters: mu (mean RT), and IIV, decomposed into variability across the entire RT distribution (sigma), and characterised by infrequent and long RTs (tau). This thesis aims to examine how the multiple cognitive demands of CPTs contributes to attentional RT/IIV, and how this relationship interacts with age, as well as pathology. The thesis aims are explored in healthy and clinical populations characterised by sustained attention impairment associated with increasing age (‘normal’ ageing and Parkinson’s disease (PD)), or in theoretical ‘accelerated ageing’ (Bipolar disorder (BD) while depressed and in remission). METHODS: Sustained attention was assessed in five cross-sectional studies, using variants of the CPT. Secondary neuropsychological measures of executive functioning, processing speed, and verbal memory were administered. Ex-Gaussian distributional parameters (mu, sigma, and tau) obtained from CPT RTs were analysed. A series of hierarchical regression analyses were examined. RESULTS: (1) In ‘normal’ ageing, better performance on the secondary neuropsychological measures was associated with faster RT (mu) and more consistent responding (sigma, tau), but this varied across CPT. Similar results were obtained for the effect of age on RT and IIV. (2) In PD, better executive functioning was associated with consistent responding (tau), whilst age was associated with slower (mu) and inconsistent (tau) responding. (3) In BD (while depressed), better executive functioning was associated with slower responding (mu), and better processing speed with consistent responding (tau), whilst age did not explain variance in RT or IIV. (4) In BD (in remission), the secondary neuropsychological measures examined did not explain variance in RT or IIV, nor did age. vi CONCLUSIONS: Attentional RT and IIV in ‘normal’ ageing and in clinical populations such as PD and BD, may be supported by secondary neuropsychological processes theorised to be involved in CPT variants. The neuropsychological profile underpinning attentional RT and IIV may reflect secondary cognitive scaffolding mechanisms, engaged depending on the age of participants, rather than the cognitive load of the task per se. The results have implications for our understanding of attentional RT and IIV in ‘normal’ ageing and pathology. Future research would further our understanding on the use of cognitive scaffolding in relation to the CPT, as well as the stability, reliability, and neurobiological origins of RT and IIV

The impact of target frequency on intra-individual variability in euthymic bipolar disorder: a comparison of two sustained attention tasks.

Greater intra-individual variability (IIV) in reaction time (RT) on a sustained attention task has been reported in patients with bipolar disorder (BD) compared with healthy controls. However, it is unclear whether IIV is task specific, or whether it represents general crosstask impairment in BD. This study aimed to investigate whether IIV occurs in sustained attention tasks with different parameters. Twenty-two patients with BD (currently euthymic) and 17 controls completed two sustained attention tasks on different occasions: a low target frequency (~20%) Vigil continuous performance test (CPT) and a high target frequency (~70%) CPT version A-X (CPT-AX). Variability measures (individual standard deviation and coefficient of variation) were calculated per participant, and ex-Gaussian modeling was also applied. This was supplemented by Vincentile analysis to characterize RT distributions. Results indicated that participants (patients and controls) were generally slower and more variable when completing the Vigil CPT compared with CPT-AX. Significant group differences were also observed in the Vigil CPT, with euthymic BD patients being more variable than controls. This result suggests that IIV in BD demonstrates some degree of task specificity. Further research should incorporate analysis of additional RT distributional models (drift diffusion and fast Fourier transform) to fully characterize the pattern of IIV in BD, as well as its relationship to cognitive processes

Exercise therapy for tendinopathy: a mixed-methods evidence synthesis exploring feasibility, acceptability and effectiveness.

Tendons are cords of strong, flexible tissue that attach muscles to bones, allowing joints to move. Tendinopathy is a common condition that can affect any tendon in the body, causing pain and limiting function. Exercise is often used to treat tendinopathy. We examined over 500 research papers on exercise for tendinopathy. The most common tendons to be studied were the calf (Achilles), knee (patellar), elbow, and shoulder. Strengthening exercise was studied most often, especially in lower limb tendinopathy. Other types of exercise such as stretching, balance and aerobic activity were less common, but were used to some extent in the upper and lower limbs. We found that exercise therapy is safe and beneficial for the tendinopathies that have been studied to date. Exercise may be most beneficial when combined with another intervention such as injection or electrotherapy. Strengthening exercise may be most beneficial for lower limb tendinopathies. However, more research is needed on the type of strengthening and the dosage, such as how many exercises and how much resistance to use. Shoulder tendinopathies may benefit from exercise that targets joint flexibility and position more than strengthening. We also found that people who receive exercise therapy for tendinopathy are generally satisfied with the effect it has on their symptoms. Finally, we found that an individualised, person-centred approach to delivering exercise therapy is valued by people with tendinopathy. They also believe that the patient-healthcare provider relationship is important for promoting the confidence and motivation people need to continue with exercise programmes, especially when they complete them independently. Although we examined a lot of papers, many of the studies were low quality. This means there is still a need for high-quality studies to tell us how effective specific types of exercise are for specific tendinopathies. There is also a need for more studies on patients' and professionals' experiences of receiving or providing exercise for tendinopathy.This project is registered as www.osf.io/a8ewy/ (scoping review); PROSPERO CRD 42020168187 (efficacy reviews); https://osf.io/preprints/sportrxiv/y7sk6/ (efficacy review 1); https://osf.io/preprints/sportrxiv/eyxgk/ (efficacy review 2); https://osf.io/preprints/sportrxiv/mx5pv/ (efficacy review 3); PROSPERO CRD42020164641 (mixed method review)

Maternal multimorbidity and preterm birth in Scotland : an observational record-linkage study

This work was funded by Northwood Charitable Trust and by the Strategic Priority Fund “Tackling multimorbidity at scale” programme (grant number MR/W014432/1) delivered by the Medical Research Council and the National Institute for Health Research in partnership with the Economic and Social Research Council and in collaboration with the Engineering and Physical Sciences Research Council.Background Multimorbidity is common in women across the life course. Preterm birth is the single biggest cause of neonatal mortality and morbidity. We aim to estimate the prevalence of multimorbidity in pregnant women and to examine the association between maternal multimorbidity and PTB. Methods This is a retrospective cohort study using electronic health records from the Scottish Morbidity Records. All pregnancies among women aged 15 to 49 with a conception date between 1 January 2014 and 31 December 2018 were included. Multimorbidity was defined as the presence of two or more pre-existing long-term physical or mental health conditions, and complex multimorbidity as the presence of four or more. It was calculated at the time of conception using a predefined list of 79 conditions published by the MuM-PreDiCT consortium. PTB was defined as babies born alive between 24 and less than 37 completed weeks of gestation. We used Generalised Estimating Equations adjusted for maternal age, socioeconomic status, number of previous pregnancies, BMI, and smoking history to estimate the effect of maternal pre-existing multimorbidity. Absolut rates are reported in the results and tables, whilst Odds Ratios (ORs) are adjusted (aOR). Results Thirty thousand five hundred fifty-seven singleton births from 27,711 pregnant women were included in the analysis. The prevalence of pre-existing multimorbidity and complex multimorbidity was 16.8% (95% CI: 16.4–17.2) and 3.6% (95% CI: 3.3–3.8), respectively. The prevalence of multimorbidity in the youngest age group was 10.2%(95% CI: 8.8–11.6), while in those 40 to 44, it was 21.4% (95% CI: 18.4–24.4), and in the 45 to 49 age group, it was 20% (95% CI: 8.9–31.1). In women without multimorbidity, the prevalence of PTB was 6.7%; it was 11.6% in women with multimorbidity and 15.6% in women with complex multimorbidity. After adjusting for maternal age, socioeconomic status, number of previous pregnancies, Body Mass Index (BMI), and smoking, multimorbidity was associated with higher odds of PTB (aOR = 1.64, 95% CI: 1.48–1.82). Conclusions Multimorbidity at the time of conception was present in one in six women and was associated with an increased risk of preterm birth. Multimorbidity presents a significant health burden to women and their offspring. Routine and comprehensive evaluation of women with multimorbidity before and during pregnancy is urgently needed.Publisher PDFPeer reviewe

Polypharmacy during pregnancy and associated risk factors : a retrospective analysis of 577 medication exposures among 1.5 million pregnancies in the UK, 2000-2019

This work was funded by the Strategic Priority Fund “Tackling multimorbidity at scale” programme [grant number MR/W014432/1] delivered by the Medical Research Council and the National Institute for Health Research in partnership with the Economic and Social Research Council and in collaboration with the Engineering and Physical Sciences Research Council. BT was funded by the National Institute for Health Research (NIHR) West Midlands Applied Research Collaboration. AA, KP and SIL were funded as NIHR Academic Clinical Fellows.Background The number of medications prescribed during pregnancy has increased over the past few decades. Few studies have described the prevalence of multiple medication use among pregnant women. This study aims to describe the overall prevalence over the last two decades among all pregnant women and those with multimorbidity and to identify risk factors for polypharmacy in pregnancy. Methods A retrospective cohort study was conducted between 2000 and 2019 using the Clinical Practice Research Datalink (CPRD) pregnancy register. Prescription records for 577 medication categories were obtained. Prevalence estimates for polypharmacy (ranging from 2+ to 11+ medications) were presented along with the medications commonly prescribed individually and in pairs during the first trimester and the entire pregnancy period. Logistic regression models were performed to identify risk factors for polypharmacy. Results During the first trimester (812,354 pregnancies), the prevalence of polypharmacy ranged from 24.6% (2+ medications) to 0.1% (11+ medications). During the entire pregnancy period (774,247 pregnancies), the prevalence ranged from 58.7 to 1.4%. Broad-spectrum penicillin (6.6%), compound analgesics (4.5%) and treatment of candidiasis (4.3%) were commonly prescribed. Pairs of medication prescribed to manage different long-term conditions commonly included selective beta 2 agonists or selective serotonin re-uptake inhibitors (SSRIs). Risk factors for being prescribed 2+ medications during the first trimester of pregnancy include being overweight or obese [aOR: 1.16 (1.14–1.18) and 1.55 (1.53–1.57)], belonging to an ethnic minority group [aOR: 2.40 (2.33–2.47), 1.71 (1.65–1.76), 1.41 (1.35–1.47) and 1.39 (1.30–1.49) among women from South Asian, Black, other and mixed ethnicities compared to white women] and smoking or previously smoking [aOR: 1.19 (1.18–1.20) and 1.05 (1.03–1.06)]. Higher and lower age, higher gravidity, increasing number of comorbidities and increasing level of deprivation were also associated with increased odds of polypharmacy. Conclusions The prevalence of polypharmacy during pregnancy has increased over the past two decades and is particularly high in younger and older women; women with high BMI, smokers and ex-smokers; and women with multimorbidity, higher gravidity and higher levels of deprivation. Well-conducted pharmaco-epidemiological research is needed to understand the effects of multiple medication use on the developing foetus.Publisher PDFPeer reviewe

The development of a core outcome set for studies of pregnant women with multimorbidity

Acknowledgements We would like to thank the following individuals, organisations and many others for helping with the recruitment of the Delphi surveys: 4M Mentor Mothers, African and Caribbean Support Northern Ireland, Alopecia UK, Ammalife, Association of South Asian Midwives, Attention Deficit Hyperactivity Disorder UK, Autism Connected, Balachandran Kumarendran, Birthrights, Black Female Doctors UK, Black Mothers Matter, Bliss, Breast Cancer Now, Bristol, North Somerset and South Gloucestershire Maternity Voices Partnership, British Adult Congenital Cardiac Nurse Association, British Association of Perinatal Medicine, British Human Immunodeficiency Virus Association, British Intrapartum Care Society, British Maternal and Fetal Medicine Society, British Thyroid Foundation, Cardiff Lupus Support Group, Cardiomyopathy UK, Chelsea and Westminster Maternity Voices Partnership, Community of Cultures Sheffield Maternity Cooperation, Core Outcome Measures in Effectiveness Trials Initiative, Crohn's and Colitis Canada, Crohn's and Colitis UK, Dads Matter, Diabetes UK, Disability Maternity Care (Australia), Elly Charity, E69 MOTIVE Trial, Epilepsy Foundation of America, Epilepsy Society, Fair Treatment for the Women of Wales, Fibromyalgia Action UK, General Practitioners Championing Perinatal Care, Global Kidney Foundation, Graham Mcllroy, Haemophilia Foundation Australia, Hereditary Spastic Paraplegia Support Group, Institute of Health Visiting, International League Against Epilepsy (Africa), Irish Neonatal Health Alliance, Juvenile Diabetes Research Foundation, Katie's Team, Kidney Patient Involvement Network, Kidney Wales, LGBT Mummies, MacDonald Obstetric Medicine Society, Malaysian Obstetric Medicine, Maternity and Midwifery Forum, MIDIRS Midwifery Digest, Midlands Maternal Medicine Network, Milena Forte, MQ Mental Health Research, Multiple Sclerosis Australia, Mums Like Us, Mum's Pride, Mumsnet, Muslim Women's Network UK, National Childbirth Trust, National Human Immunodeficiency Virus Nurses Association, National Kidney Federation, National Rheumatoid Arthritis UK, Newport Yemeni Community Association, Niina Kolehmainen, Obsessive Compulsive Disorder Action, Obstetric Anaesthetists' Association, Organisation for Sickle Cell Anaemia Relief and Thalassaemia Support Birmingham, Parathyroid UK, Parent Voices in Wales, Parents 1st 83 , Positive East, Positive Life Northern Ireland, Postural Tachycardia Syndrome UK, Psoriasis Association, Raham Project, Royal College of Midwives, Royal Surrey County Hospital Maternity Voices Partnership, Scottish 86 Perinatal Network, Scottish Research Nurse, Midwife & Coordinators' Network, Section for Women's Mental Health Institute of Psychiatry, Psychology and Neuroscience (King's College London), Sjogern's India, Society of Obstetric Medicine of Australia and New Zealand, Society of Obstetric Medicine (India), Somerville Heart Foundation, Sophia Forum, South African Nephrology Society, South Asian Health Foundation, South London Applied Research Collaboration Maternal and Perinatal Mental Health Research Patient and Public Involvement, Stockport Foundation Trust, Taraki, The Black Wellbeing Collective, The International Marcé Society for Perinatal Mental Health, The Pituitary Foundation, Thyroid Patients Canada, Tommy's, Turner Syndrome Support Society UK, UK Audit and Research Collaborative in Obstetrics and Gynaecology, UK Preconception Early-and Mid-Career Researchers Network, UK Teratology Information Service, University of Bristol Centre for Academic Primary Care and Patient and Public Involvement Panel, Vasculitis Ireland Awareness, Verity Polycystic Ovarian Syndrome UK, Wales Perinatal Mental Health Network. We would also like to thank Clare Evans for her input in reviewing this manuscript Funding This work was funded by the Strategic Priority Fund “Tackling multimorbidity at scale” programme (grant number MR/W014432/1) delivered by the Medical Research Council and the National Institute for Health Research in partnership with the Economic and Social Research Council and in collaboration with the Engineering and Physical Sciences Research Council. BT was funded by the National Institute for Health Research (NIHR) West Midlands Applied Research Collaboration. The views expressed are those of the author and not necessarily those of the funders, the NIHR or the UK Department of Health and Social Care. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Mortality Among Adults With Cancer Undergoing Chemotherapy or Immunotherapy and Infected With COVID-19

Importance: Large cohorts of patients with active cancers and COVID-19 infection are needed to provide evidence of the association of recent cancer treatment and cancer type with COVID-19 mortality. // Objective: To evaluate whether systemic anticancer treatments (SACTs), tumor subtypes, patient demographic characteristics (age and sex), and comorbidities are associated with COVID-19 mortality. // Design, Setting, and Participants: The UK Coronavirus Cancer Monitoring Project (UKCCMP) is a prospective cohort study conducted at 69 UK cancer hospitals among adult patients (≥18 years) with an active cancer and a clinical diagnosis of COVID-19. Patients registered from March 18 to August 1, 2020, were included in this analysis. // Exposures: SACT, tumor subtype, patient demographic characteristics (eg, age, sex, body mass index, race and ethnicity, smoking history), and comorbidities were investigated. // Main Outcomes and Measures: The primary end point was all-cause mortality within the primary hospitalization. // Results: Overall, 2515 of 2786 patients registered during the study period were included; 1464 (58%) were men; and the median (IQR) age was 72 (62-80) years. The mortality rate was 38% (966 patients). The data suggest an association between higher mortality in patients with hematological malignant neoplasms irrespective of recent SACT, particularly in those with acute leukemias or myelodysplastic syndrome (OR, 2.16; 95% CI, 1.30-3.60) and myeloma or plasmacytoma (OR, 1.53; 95% CI, 1.04-2.26). Lung cancer was also significantly associated with higher COVID-19–related mortality (OR, 1.58; 95% CI, 1.11-2.25). No association between higher mortality and receiving chemotherapy in the 4 weeks before COVID-19 diagnosis was observed after correcting for the crucial confounders of age, sex, and comorbidities. An association between lower mortality and receiving immunotherapy in the 4 weeks before COVID-19 diagnosis was observed (immunotherapy vs no cancer therapy: OR, 0.52; 95% CI, 0.31-0.86). // Conclusions and Relevance: The findings of this study of patients with active cancer suggest that recent SACT is not associated with inferior outcomes from COVID-19 infection. This has relevance for the care of patients with cancer requiring treatment, particularly in countries experiencing an increase in COVID-19 case numbers. Important differences in outcomes among patients with hematological and lung cancers were observed

The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Staphylococcus aureus bacteraemia is a common cause of severe community-acquired and hospital-acquired infection worldwide. We tested the hypothesis that adjunctive rifampicin would reduce bacteriologically confirmed treatment failure or disease recurrence, or death, by enhancing early S aureus killing, sterilising infected foci and blood faster, and reducing risks of dissemination and metastatic infection. METHODS: In this multicentre, randomised, double-blind, placebo-controlled trial, adults (≥18 years) with S aureus bacteraemia who had received ≤96 h of active antibiotic therapy were recruited from 29 UK hospitals. Patients were randomly assigned (1:1) via a computer-generated sequential randomisation list to receive 2 weeks of adjunctive rifampicin (600 mg or 900 mg per day according to weight, oral or intravenous) versus identical placebo, together with standard antibiotic therapy. Randomisation was stratified by centre. Patients, investigators, and those caring for the patients were masked to group allocation. The primary outcome was time to bacteriologically confirmed treatment failure or disease recurrence, or death (all-cause), from randomisation to 12 weeks, adjudicated by an independent review committee masked to the treatment. Analysis was intention to treat. This trial was registered, number ISRCTN37666216, and is closed to new participants. FINDINGS: Between Dec 10, 2012, and Oct 25, 2016, 758 eligible participants were randomly assigned: 370 to rifampicin and 388 to placebo. 485 (64%) participants had community-acquired S aureus infections, and 132 (17%) had nosocomial S aureus infections. 47 (6%) had meticillin-resistant infections. 301 (40%) participants had an initial deep infection focus. Standard antibiotics were given for 29 (IQR 18-45) days; 619 (82%) participants received flucloxacillin. By week 12, 62 (17%) of participants who received rifampicin versus 71 (18%) who received placebo experienced treatment failure or disease recurrence, or died (absolute risk difference -1·4%, 95% CI -7·0 to 4·3; hazard ratio 0·96, 0·68-1·35, p=0·81). From randomisation to 12 weeks, no evidence of differences in serious (p=0·17) or grade 3-4 (p=0·36) adverse events were observed; however, 63 (17%) participants in the rifampicin group versus 39 (10%) in the placebo group had antibiotic or trial drug-modifying adverse events (p=0·004), and 24 (6%) versus six (2%) had drug interactions (p=0·0005). INTERPRETATION: Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S aureus bacteraemia. FUNDING: UK National Institute for Health Research Health Technology Assessment