551 research outputs found

    New data and the hard pomeron

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    New structure-function data are in excellent agreement with the existence of a hard pomeron, with intercept about 1.4. It gives a very economical description of the data. Having fixed 2 parameters from the data for the real-photon cross section σγp\sigma^{\gamma p}, we need just 5 further parameters to fit the data for F2(x,Q2)F_2(x,Q^2) with x0.001x\leq 0.001. The available data range from Q2=0.045Q^2=0.045 to 35 GeV2^2. With guesses consistent with dimensional counting for the xx dependences of our three separate terms, the fit extends well to larger xx and to Q2=5000Q^2=5000 GeV2^2. With no additional parameters, it gives a good description of data for the charm structure function F2c(x,Q2)F_2^c(x,Q^2) from Q2=0Q^2=0 to 130 GeV2^2. The two pomerons also give a good description of both the WW and the tt dependence of γpJ/ψp\gamma p\to J/\psi p.Comment: 11 pages, plain tex, with 10 figures embedded using epsf. (Spurious figure removed.

    Cost-effectiveness of paediatric central venous catheters in the UK:A secondary publication from the CATCH clinical trial

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    Background: Antibiotic-impregnated central venous catheters (CVCs) reduce the risk of bloodstream infections (BSIs) in patients treated in pediatric intensive care units (PICUs). However, it is unclear if they are cost-effective from the perspective of the National Health Service (NHS) in the UK.Methods: Economic evaluation alongside the CATCH trial (ISRCTN34884569) to estimate the incremental cost effectiveness ratio (ICER) of antibiotic-impregnated (rifampicin and minocycline), heparin-bonded and standard polyurethane CVCs. The 6-month costs of CVCs and hospital admissions and visits were determined from administrative hospital data and case report forms.Results: BSIs were detected in 3.59% (18/502) of patients randomized to standard, 1.44% (7/486) to antibiotic and 3.42% (17/497) to heparin CVCs. Lengths of hospital stay did not differ between intervention groups. Total mean costs (95% confidence interval) were: £45,663 (£41,647–£50,009) for antibiotic, £42,065 (£38,322–£46,110) for heparin, and £44,503 (£40,619–£48,666) for standard CVCs. As heparin CVCs were not clinically effective at reducing BSI rate compared to standard CVCs, they were considered not to be cost-effective. The ICER for antibiotic vs. standard CVCs, of £54,057 per BSI avoided, was sensitive to the analytical time horizon.Conclusions: Substituting standard CVCs for antibiotic CVCs in PICUs will result in reduced occurrence of BSI but there is uncertainty as to whether this would be a cost-effective strategy for the NHS

    The cost-effectiveness of strategies preventing late-onset infection in preterm infants

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    Objective: Developing a model to analyse the cost-effectiveness of interventions preventing late-onset infection (LOI) in preterm infants and applying it to the evaluation of Anti-Microbial Impregnated Peripherally Inserted Central Catheters (AM-PICCs) compared with standard PICCs (S-PICCs). Design: Model-based cost-effectiveness analysis, using data from the PREVAIL randomised controlled trial linked to routine healthcare data, supplemented with published literature. The model assumes that LOI increases the risk of neurodevelopmental impairment (NDI). Setting: Neonatal Intensive Care Units in the UK National Health Service (NHS). Patients: Infants born ≤32 weeks gestational age, requiring a 1 French gauge PICC. Interventions: AM-PICC and S-PICC. Main outcome measures: Life expectancy, quality-adjusted life years and healthcare costs over the infants’ expected lifetime. Results: Severe NDI reduces life expectancy by 14.79 (95% confidence interval (CI) 4.43; 26.68; undiscounted) years, 10.63 (95%CI 7.74; 14.02; discounted) QALYs, and costs £19,060 (95%CI £14,197; £24,70; discounted) to the NHS. If LOI causes NDI, the maximum acquisition price of an intervention reducing LOI risk by 5% is £120. AM-PICCs increase costs (£54.85 (95%CI £25.95; £89.12)) but have negligible impact on health outcomes (-0.01 (95%CI -0.09; 0.04) QALYs), compared with S-PICCs. The NHS can invest up to £2.4 million in research to confirm that AM-PICCs are not cost-effective. Conclusions: The model quantifies health losses and additional healthcare costs caused by NDI and LOI during neonatal care. Given these consequences, interventions preventing LOI, even by a small extent, can be cost-effective. AM-PICCs, being less effective and more costly than S-PICC, are not likely to be cost-effective

    Family adversity and health characteristics associated with intimate partner violence in children and parents presenting to health care: a population-based birth cohort study in England

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    BACKGROUND: Little is known about the clinical characteristics of children and parents affected by intimate partner violence (IPV) presenting in health-care settings. We examined the associations between family adversities, health characteristics, and IPV in children and parents using linked electronic health records (EHRs) from primary and secondary care between 1 year before and 2 years after birth (the first 1000 days). We compared parental health problems in in children and parents with and without recorded IPV. METHODS: We developed a population-based birth cohort of children and parents (aged 14-60 years) in England, comprising linked EHRs from mother-child pairs (with no identified father) and mother-father-child triads. We followed the cohort across general practices (Clinical Practice Research Datalink GOLD), emergency departments, outpatient visits, hospital admissions, and mortality records. Family adversities included 33 clinical indicators of parental mental health problems, parental substance misuse, adverse family environments, and high-risk child maltreatment-related presentations. Parental health problems included 12 common comorbidities, ranging from diabetes and cardiovascular diseases to chronic pain or digestive diseases. We used adjusted and weighted logistic-regression models to estimate the probability of IPV (per 100 children and parents) associated with each adversity, and period prevalences of parental health problems associated with IPV. FINDINGS: We included 129 948 children and parents, comprising 95 290 (73·3%) mother-father-child triads and 34 658 (26·7%) mother-child pairs only between April 1, 2007, and Jan 29, 2020. An estimated 2689 (2·1%) of 129 948 children and parents (95% CI 2·0-2·3) had recorded IPV and 54 758 (41·2%; 41·5-42·2) had any family adversity between 1 year before and 2 years after birth. All family adversities were significantly associated with IPV. Most parents and children with IPV had recorded adversities (1612 [60·0%] of 2689) before their first IPV recording. The probability of IPV was 0·6 per 100 children and parents (95% CI 0·5-0·6) with no adversity, increasing to 4·4 per 100 children per parents (4·2-4·7) with one adversity, and up to 15·1 per 100 parents and children (13·6-16·5) with three of more adversities. Mothers with IPV had a significantly higher prevalence of both physical (73·4% vs 63·1%, odds ratio [OR] 1·6, 95% CI 1·4-1·8) and mental health problems (58·4% vs 22·2%, OR 4·9, 4·4-5·5) than mothers without IPV. Fathers with IPV had a higher prevalence of mental health problems (17·8% vs 7·1%, OR 2·8, 2·4-3·2) and similar prevalences of physical health problems than those without IPV (29·6% vs 32·4%, OR 0·9, 0·8-1·0). INTERPRETATION: Two in five of the children and parents presenting to health care had recorded parental mental health problems, parental substance misuse, adverse family environments, or high-risk presentations of maltreatment in the first 1000 days. One in 22 children and parents with family adversity also had recorded IPV before age 2 years. Primary and secondary care staff should safely ask about IPV when parents or children present with family adversity or health problems associated with IPV, and respond appropriately. FUNDING: NIHR Policy Research Programme

    A guide to evaluating linkage quality for the analysis of linked data.

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    Linked datasets are an important resource for epidemiological and clinical studies, but linkage error can lead to biased results. For data security reasons, linkage of personal identifiers is often performed by a third party, making it difficult for researchers to assess the quality of the linked dataset in the context of specific research questions. This is compounded by a lack of guidance on how to determine the potential impact of linkage error. We describe how linkage quality can be evaluated and provide widely applicable guidance for both data providers and researchers. Using an illustrative example of a linked dataset of maternal and baby hospital records, we demonstrate three approaches for evaluating linkage quality: applying the linkage algorithm to a subset of gold standard data to quantify linkage error; comparing characteristics of linked and unlinked data to identify potential sources of bias; and evaluating the sensitivity of results to changes in the linkage procedure. These approaches can inform our understanding of the potential impact of linkage error and provide an opportunity to select the most appropriate linkage procedure for a specific analysis. Evaluating linkage quality in this way will improve the quality and transparency of epidemiological and clinical research using linked data

    Psychosocial work factors and social inequalities in psychological distress: a population-based study.

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    BACKGROUND: Mental health problems (MHP) are the leading cause of disability worldwide. The inverse association between socioeconomic position (SEP) and MHP has been well documented. There is prospective evidence that factors from the work environment, including adverse psychosocial work factors, could contribute to the development of MHP including psychological distress. However, the contribution of psychosocial work factors to social inequalities in MHP remains unclear. This study evaluates the contribution of psychosocial work factors from two highly supported models, the Demand-Control-Support (DCS) and the Effort-Reward Imbalance (ERI) models to SEP inequalities of psychological distress in men and women from a population-based sample of Quebec workers. METHODS: Data were collected during a survey on working conditions, health and safety at work. SEP was evaluated using education, occupation and household income. Psychosocial work factors and psychological distress were assessed using validated instruments. Mean differences (MD) in the score of psychological distress were estimated separately for men and women. RESULTS: Low education level and low household income were associated with psychological distress among men (MD, 0.56 (95% CI 0.06; 1.05) and 1.26 (95% CI 0.79; 1.73) respectively). In men, the contribution of psychosocial work factors from the DCS and the ERI models to the association between household income and psychological distress ranged from 9% to 24%. No clear inequalities were observed among women. CONCLUSIONS: These results suggest that psychosocial work factors from the DCS and the ERI models contribute to explain a part of social inequalities in psychological distress among men. Psychosocial factors at work are frequent and modifiable. The present study supports the relevance of targeting these factors for the primary prevention of MHP and for health policies aiming to reduce social inequalities in mental health

    Association between congenital toxoplasmosis and parent-reported developmental outcomes, concerns, and impairments, in 3 year old children

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    BACKGROUND: Information is lacking on the effects of congenital toxoplasmosis on development, behavior, and impairment in later childhood, as well as on parental concerns and anxiety. This information is important for counselling parents about the prognosis for an infected child and for policy decisions on screening. METHODS: We prospectively studied a cohort of children identified by screening for toxoplasmosis in pregnant women or neonates between 1996 and 2000 in ten European centers. At 3 years of age, parents of children with and without congenital toxoplasmosis were surveyed about their child's development, behavior, and impairment, and about parental concerns and anxiety, using a postal questionnaire. RESULTS: Parents of 178/223 (80%) infected, and 527/821 (64%) uninfected children responded. We found no evidence that impaired development or behavior were more common in infected children, or that any potential effect of congenital toxoplasmosis was masked by prenatal treatment. Parents of infected children were significantly more anxious and reported more visual problems in their children. CONCLUSION: On average, children aged three to four years with congenital toxoplasmosis identified by screening and treated during infancy in this European setting had risks of abnormal development and behavior similar to uninfected children. Parental anxiety about infected children needs to be addressed by clinicians. Future studies with longer follow up and clinician-administered assessments may be better able to detect any subtle differences in child outcomes

    Impregnated central venous catheters for prevention of bloodstream infection in children (the CATCH trial): a randomised controlled trial.

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    BACKGROUND: Impregnated central venous catheters are recommended for adults to reduce bloodstream infections but not for children because there is not enough evidence to prove they are effective. We aimed to assess the effectiveness of any type of impregnation (antibiotic or heparin) compared with standard central venous catheters to prevent bloodstream infections in children needing intensive care. METHODS: We did a randomised controlled trial of children admitted to 14 English paediatric intensive care units. Children younger than 16 years were eligible if they were admitted or being prepared for admission to a participating paediatric intensive care unit and were expected to need a central venous catheter for 3 or more days. Children were randomly assigned (1:1:1) to receive a central venous catheter impregnated with antibiotics, a central venous catheter impregnated with heparin, or a standard central venous catheter with computer generated randomisation in blocks of three and six, stratified by method of consent, site, and envelope storage location within the site. The clinician responsible for inserting the central venous catheter was not masked to allocation, but allocation was concealed from patients, their parents, and the paediatric intensive care unit personnel responsible for their care. The primary outcome was time to first bloodstream infection between 48 h after randomisation and 48 h after central venous catheter removal with impregnated (antibiotic or heparin) versus standard central venous catheters, assessed in the intention-to-treat population. Safety analyses compared central venous catheter-related adverse events in the subset of children for whom central venous catheter insertion was attempted (per-protocol population). This trial is registered with ISRCTN number, ISRCTN34884569. FINDINGS: Between Nov 25, 2010, and Nov 30, 2012, 1485 children were recruited to this study. We randomly assigned 502 children to receive standard central venous catheters, 486 to receive antibiotic-impregnated catheters, and 497 to receive heparin-impregnated catheters. Bloodstream infection occurred in 18 (4%) of those in the standard catheters group, 7 (1%) in the antibiotic-impregnated group, and 17 (3%) assigned to heparin-impregnated catheters. Primary analyses showed no effect of impregnated (antibiotic or heparin) catheters compared with standard central venous catheters (hazard ratio [HR] for time to first bloodstream infection 0.71, 95% CI 0.37-1.34). Secondary analyses showed that antibiotic central venous catheters were better than standard central venous catheters (HR 0.43, 0.20-0.96) and heparin central venous catheters (HR 0.42, 0.19-0.93), but heparin did not differ from standard central venous catheters (HR 1.04, 0.53-2.03). Clinically important and statistically significant absolute risk differences were identified only for antibiotic-impregnated catheters versus standard catheters (-2.15%, 95% CI -4.09 to -0.20; number needed to treat [NNT] 47, 95% CI 25-500) and antibiotic-impregnated catheters versus heparin-impregnated catheters (-1.98%, -3.90 to -0.06, NNT 51, 26-1667). Nine children (2%) in the standard central venous catheter group, 14 (3%) in the antibiotic-impregnated group, and 8 (2%) in the heparin-impregnated group had catheter-related adverse events. 45 (8%) in the standard group, 35 (8%) antibiotic-impregnated group, and 29 (6%) in the heparin-impregnated group died during the study. INTERPRETATION: Antibiotic-impregnated central venous catheters significantly reduced the risk of bloodstream infections compared with standard and heparin central venous catheters. Widespread use of antibiotic-impregnated central venous catheters could help prevent bloodstream infections in paediatric intensive care units. FUNDING: National Institute for Health Research, UK

    The Lantern Vol. 3, No. 2, March 1935

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    • Puppets of Propaganda • Reluctance • Reflections From My Diary • Reverie • Bash Turner Enters the Limelight • The College Students\u27 Obligation • The Schwenkfelders • Love\u27s Desire • Verse • On the Squirt of a Grapefruit • Pioneers! • Whither Fraternities? • Mary Peters: A Book Review • Different as Night and Day • Ode to an Alley Cathttps://digitalcommons.ursinus.edu/lantern/1005/thumbnail.jp
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