1,721,087 research outputs found
Prediction of long-term outcome subtypes in ARDS: first steps towards personalised medicine in critical care
Full text linkCan the association of adult lung function with weight in early life be explained by early life factors?
No full textIntroductionWeight in early life is known to be associated with forced vital capacity (FVC) in adulthood, but whether it is also associated with airflow obstruction (FEV1/FVC) in adulthood is unclear. The observed association between weight in early life and lung function could be confounded by maternal risk factors, such as maternal smoking. Therefore, we examine whether maternal factors might explain this association.MethodsUsing linear regression among 3,832 participants of the Northern Finland Birth Cohort 1966, we examined the association of adult lung function (FVC and FEV1/FVC) with weight in early life (birth weight and weight gain in the first year of life). We then tested whether this association could be explained by maternal factors (maternal weight, height, BMI, age, smoking, education, socio-economic status and parity) by adjusting for them.ResultsFVC was positively associated with birth weight and weight gain. FEV1/FVC was not associated with birth weight and was negatively associated with weight gain. Mean FVC in adulthood (95%CI) increased by 86mL (51,121) and 24mL (7.7, 40) for each kilogram increase in birth weight and weight gain, respectively. One kg increase in weight gain was associated with a reduction of 0.003 units (-0.004,-0.001) of FEV1/FVC. Although several maternal factors were associated with both adult lung function and weight in early life, adjusting for them did not substantially alter the results.ConclusionAdult lung function and weight in early life were both associated with several early life factors, but these did not explain the association between adult lung function and weight in early life.<br/
Risk factors for post-operative eye pain in patients with non-painful eye disease undergoing pars plana vitrectomy: the VItrectomy Pain (VIP) study
No full textBACKGROUND: Pars Plana Vitrectomy (PPV), a surgical procedure used to treat different ophthalmic pathologies, could be associated with moderate to severe eye pain The aim of the present study was to evaluate the incidence of postoperative eye pain and its risk factors following Pars Plana Vitrectomy (PPV) in a selected population of patients with non-painful eye disease, receiving regional anaesthesia and moderate sedation with benzodiazepines, without use of narcotics.METHODS: Single-center, prospective observational cohort study. We recorded the presence of pain at operating room discharge, at 6 and 24 hours, using the numeric rating scale (NRS). We recorded also age, sex, ethnic origin, American Society of Anaesthesia physical status (ASA PS) classification, Charlson Comorbidity Index, the aetiology of the vitreoretinal pathology, length of surgery, and type of surgical procedure performed.RESULTS: Eye pain (NRS > 3) was present in 3 patients (0.7%) at operating room discharge, 59 (13.2%) at 6 and 65 (14.6%) at 24 hours after surgery. LASSO logistic regression analysis identified age, ASA PS, race, along with tamponade as independent risk factors for eye pain at 6 hours. Scleral buckling was selected for eye pain at 24 hrs.CONCLUSIONS: A protocol for pain control after PPV should be considered, especially in younger, non-Caucasian people, and patients with high ASA PS grade. Moreover, attention must be paid when additional surgical procedures are requested, restricting them to selected patients, and using the appropriate agent for intraocular tamponade
Using a Bayesian approach and external validation to predict persistent asthma at the age of 10 and 20 years in general and high-risk populations
No full textEffects of BMI, fat mass, and lean mass on asthma in childhood : a Mendelian Randomization Study
Full text linkBackground
Observational studies have reported associations between body mass index (BMI) and asthma, but confounding and reverse causality remain plausible explanations. We aim to investigate evidence for a causal effect of BMI on asthma using a Mendelian randomization approach.
Methods and Findings
We used Mendelian randomization to investigate causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ y in the Avon Longitudinal Study of Parents and Children (ALSPAC). A weighted allele score based on 32 independent BMI-related single nucleotide polymorphisms (SNPs) was derived from external data, and associations with BMI, fat mass, lean mass, and asthma were estimated. We derived instrumental variable (IV) estimates of causal risk ratios (RRs). 4,835 children had available data on BMI-associated SNPs, asthma, and BMI. The weighted allele score was strongly associated with BMI, fat mass, and lean mass (all p-values<0.001) and with childhood asthma (RR 2.56, 95% CI 1.38–4.76 per unit score, p = 0.003). The estimated causal RR for the effect of BMI on asthma was 1.55 (95% CI 1.16–2.07) per kg/m2, p = 0.003. This effect appeared stronger for non-atopic (1.90, 95% CI 1.19–3.03) than for atopic asthma (1.37, 95% CI 0.89–2.11) though there was little evidence of heterogeneity (p = 0.31). The estimated causal RRs for the effects of fat mass and lean mass on asthma were 1.41 (95% CI 1.11–1.79) per 0.5 kg and 2.25 (95% CI 1.23–4.11) per kg, respectively. The possibility of genetic pleiotropy could not be discounted completely; however, additional IV analyses using FTO variant rs1558902 and the other BMI-related SNPs separately provided similar causal effects with wider confidence intervals. Loss of follow-up was unlikely to bias the estimated effects.
Conclusions
Higher BMI increases the risk of asthma in mid-childhood. Higher BMI may have contributed to the increase in asthma risk toward the end of the 20th century
The application of bayesian and frequentist regularization and variable selection methods for the prediction of asthma in later childhood
Full text linkAsthma is a global health problem and among the most common chronic conditions in childhood. Several models were proposed to predict asthma in children, but their reproducibility in external populations was limited and none was developed to predict asthma in adolescence.
I conducted a systematic review of asthma predictive models validated in external populations; validation studies showed poorer predictive performances than development studies.
I developed predictive models for asthma between 15 and 20 years, using data from the Study Team for Early Life Asthma Research (STELAR) consortium of five UK asthma cohorts. For one of these cohorts, the Ashford study, I developed an questionnaire to collect follow-up information when study subjects were age 20 years.
I harmonised 41 variables across the STELAR cohorts, 39 of which were used as candidate predictors to develop predictive models, while the others were used to define asthma at 15–20 years. Asthma at that age was defined as positive responses to ‘current wheezing’ and ‘asthma medications in the last year’.Two of the five STELAR cohorts (development data) were combined to develop predictive models using stepwise regression and frequentist, Bayesian and empirical Bayes regularization models. The remaining cohorts (validation data) were used to assess predictive performance using discrimination and accuracy measures. Analyses were performed in two populations - all children and a subgroup with reported wheezing between two and five years (high-risk population). Sex, eczema, sensitization to house dust mite and doctor’s diagnosis of asthma in early childhood (4-7 years) were identified as asthma predictors at 15-20 years in both populations. Additional predictors in the general population included early wheezing symptoms and parental allergies, while in the high-risk population maternal allergies and pet in the house at one year were important for asthma prediction in adolescence. Sensitivity was higher in the general population, whereas positive predictive value was higher in the high-risk population. Although accuracy was good in both populations, the predictive ability of the models developed was limited.Open Acces
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Evaluation of strategies for reducing the burden of COPD in the UK using Bayesian methods
Full text linkChronic obstructive pulmonary disease (COPD) is responsible for 5.3% of all deaths and 1.7% of all hospital admissions in the UK. This thesis focuses on strategies to reduce COPD burden by targeting three aspects across the public healthcare system: prevention, emergency treatment, and long-term management. Analyses were performed in a Bayesian framework to exploit its flexibility in modelling uncertainty and the incorporation of prior knowledge.
First, I assessed whether communication of personalised disease risk in primary care is an effective smoking cessation intervention, using cost-effectiveness and value of information analyses based on various data sources across the literature. The odds ratio for the effectiveness of communication of personalised disease risk was 1.48 (95%CrI:0.91-2.26). While I found a probability of cost-effectiveness of about 90%, further research up to a maximum of £27 million is justified to reduce the uncertainty around this estimate.
Secondly, I assessed whether case ascertainment affects the detection of poorly performing hospital trusts in the treatment of acute exacerbation of COPD (AECOPD) in secondary care, using data from the National Asthma and COPD Audit Programme. Case ascertainment was associated with 30-day mortality (OR:1.74; 1.25-2.41) and adjusting for it impacted the findings, with 5 trusts becoming outliers and 2 trusts no longer classified as outliers.
Finally, using general practice data from Clinical Practice Research Datalink, I assessed whether new guidelines suggesting triple therapy (long-acting beta-2 agonists, LABA + long-acting muscarinic antagonists, LAMA + inhaled corticosteroids, ICS) for the treatment of those with poorly-controlled COPD on LABA+LAMA dual therapy improves disease outcomes. Triple therapy was not associated with severe AECOPD (IRR:1.00; 0.93-1.07) or mortality (IRR:0.95; 0.86-1.06), but was associated with increased risk of pneumonia (IRR:1.19; 1.05-1.35).
This thesis applied sophisticated Bayesian methods to increase understanding of how COPD burden could be reduced in different areas of the public healthcare system.Open Acces
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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