11,560 research outputs found

    Secondhand smoke exposure and risk of incident peripheral arterial disease and mortality: a Scotland-wide retrospective cohort study of 4045 non-smokers with cotinine measurement

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    Background: Active smoking is an important risk factor for all-cause mortality and peripheral arterial disease (PAD). In contrast, published studies on the associations with secondhand smoke (SHS) are limited. The aim of this study was to examine the associations between SHS exposure and incident PAD, as well as mortality, among middle-aged non-smokers. Methods: We undertook a retrospective, cohort study using record linkage of the Scottish Health Surveys between 1998 and 2010 to hospital admissions and death certificates. Inclusion was restricted to participants aged > 45 years. Cox proportional hazard models were used to examine the association between SHS exposure and incident PAD (hospital admission or death) and all-cause mortality, with adjustment for potential confounders. Results: Of the 4045 confirmed non-smokers (self-reported non-smokers with salivary cotinine concentrations < 15 ng/mL), 1163 (28.8%) had either moderate or high exposure to SHS at baseline. In men, high exposure to SHS (cotinine ≥2.7 ng/mL) was associated with increased risk of all-cause mortality (fully adjusted hazard ratio [HR] 1.54, 95% CI 1.07–2.22, p = 0.020) with evidence of a dose-relationship (p for trend = 0.004). In men, high exposure to SHS was associated with increased risk of incident PAD over the first five years of follow-up (fully adjusted HR 4.29, 95% CI 1.14–16.10, p = 0.031) but the association became non-significant over longer term follow-up. Conclusions: SHS exposure was independently associated with all-cause mortality and may be associated with PAD, but larger studies, or meta-analyses, are required to confirm the latter

    Association between self-reported general and mental health and adverse outcomes: a retrospective cohort study of 19 625 Scottish adults

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    <b>Objective</b><p></p> Self-reported general health and mental health are independent predictors of all-cause mortality. This study examines whether they are also independent predictors of incident cancer, coronary heart disease and psychiatric hospitalisation. <b>Methods</b><p></p> We conducted a retrospective, population cohort study by linking the 19 625 Scottish adults who participated in the Scottish Health Surveys 1995–2003, to hospital admissions, cancer registration and death certificate records. We conducted Cox proportional hazard models adjusting for potential confounders including age, sex, socioeconomic status, alcohol, smoking status, body mass index, hypertension and diabetes. <b>Results</b><p></p> Poor general health was reported by 1215 (6.2%) participants and was associated with cancer registrations (adjusted Hazard Ratio [HR] 1.30, 95% CI 1.10, 1.55), coronary heart disease events (adjusted HR 2.30, 95% CI 1.86, 2.84) and psychiatric hospitalisations (adjusted HR 2.42, 95% CI 1.65, 3.56). There was evidence of dose relationships and the associations remained significant after adjustment for mental health. 3172 (16%) participants had poor mental health (GHQ ≥4). After adjustment for general health, the associations between poor mental health and coronary heart disease events (adjusted HR 1.36, 95% CI 1.13, 1.63) and all-cause death (adjusted HR 1.38, 95% CI 1.23, 1.55) became non-significant, but mental health remained associated with psychiatric hospitalisations (fully adjusted HR 2.02, 95% CI 1.48, 2.75). <b>Conclusion</b><p></p> Self-reported general health is a significant predictor of a range of clinical outcomes independent of mental health. The association between mental health and non-psychiatric outcomes is mediated by general health but it is an independent predictor of psychiatric outcome. Individuals with poor general health or mental health warrant close attention

    Lymphohaematopoietic malignancies in Scottish military veterans: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans

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    Background: Lymphohaematopoietic malignancies are common in the general population. There have been concerns that military service may be associated with increased risk as a result of occupational exposures. To date, few studies have demonstrated an increased risk, although a disability pension is payable to veterans who were present at nuclear tests and who develop leukaemia (other than chronic lymphocytic leukaemia). The aim of the study was to utilise data from the Scottish Veterans Health Study to examine the risk of lymphohaematopoietic malignancy following military service in a large national cohort of veterans. Methods: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans born between 1945 and 1985 matched for age, sex and area of residence, adjusted for areal deprivation and followed up for up to 30 years, using Cox proportional hazard models to compare the risk of lymphohaematopoietic malignancy overall, by diagnosis and by sex and birth cohort. Results: We found no statistically significant difference in risk between veterans and non-veterans either for all leukaemias (Cox proportional hazard ratio 1.03, 95% confidence intervals 0.84–1.27, p = 0.773), Hodgkin lymphoma (hazard ratio 1.19, 95% confidence intervals 0.87–1.61, p = 0.272) or for non-Hodgkin lymphoma (hazard ratio 0.86, 95% confidence intervals 0.71–1.04, p = 0.110). Conclusion: Our findings provide reassurance that service in the UK Armed Forces is not associated with increased risk of lymphohaematopoietic malignancy

    Cost-effectiveness analysis in R using a multi-state modelling survival analysis framework: a tutorial

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    This tutorial provides a step-by-step guide to performing cost-effectiveness analysis using a multi-state modelling approach. Alongside the tutorial we provide easy-to-use functions in the statistics package R. We argue this multi-state modelling approach using a package such as R has advantages over approaches where models are built in a spreadsheet package. In particular, using a syntax-based approach means there is a written record of what was done and the calculations are transparent. Reproducing the analysis is straightforward as the syntax just needs to be run again. The approach can be thought of as an alternative way to build a Markov decision analytic model, which also has the option to use a state-arrival extended approach if the Markov property does not hold. In the state-arrival extended multi-state model a covariate that represents patients’ history is included allowing the Markov property to be tested. We illustrate the building of multi-state survival models, making predictions from the models and assessing fits. We then proceed to perform a cost-effectiveness analysis including deterministic and probabilistic sensitivity analyses. Finally, we show how to create two common methods of visualising the results, namely cost-effectiveness planes and cost-effectiveness acceptability curves. The analysis is implemented entirely within R. It is based on adaptions to functions in the existing R package mstate, to accommodate parametric multi-state modelling which facilitates extrapolation of survival curves

    Renormalization and Quantum Scaling of Frenkel-Kontorova Models

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    We generalise the classical Transition by Breaking of Analyticity for the class of Frenkel-Kontorova models studied by Aubry and others to non-zero Planck's constant and temperature. This analysis is based on the study of a renormalization operator for the case of irrational mean spacing using Feynman's functional integral approach. We show how existing classical results extend to the quantum regime. In particular we extend MacKay's renormalization approach for the classical statistical mechanics to deduce scaling of low frequency effects and quantum effects. Our approach extends the phenomenon of hierarchical melting studied by Vallet, Schilling and Aubry to the quantum regime.Comment: 14 pages, 1 figure, submitted to J.Stat.Phy

    The construction of a comprehensive program of boys' track and field athletics for a city playground system

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    Thesis (Ed.M.)--Boston University, 1949. This item was digitized by the Internet Archive

    Early Communicative Skills: The Place of Communication in the Curriculum for Pupils With Severe and Profound Learning Difficulties

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    The study is concerned with the development of the area of communication in the curriculum for a group of pupils who did not become entitled to education in Scotland until 1974. These pupils have severe "mental handicap", or "learning difficulties". The study is specifically concerned with the place of communication in the curriculum of those pupils who have little or no speech. The most advanced pupils to be considered have just begun to use "two-word-sentences". The most profoundly handicapped are functioning at the level of infants in the first weeks, or even days, of life. The study traces the development of special education in Scotland for pupils with severe and profound learning difficulties. It then considers the extent to which it is possible to think of developing a curriculum for these pupils, given that they cannot follow the curricula of mainstream primary and secondary schools. It is suggested that "ecological validity" is a useful principle for guiding the development of curriculum, and for judging the value of the experiences which the pupils are offered in school. Communication is chosen as an area of the curriculum on which to focus, as difficulties in the development of communication are a characteristic of mental handicap. The nature of communication is examined. It is suggested that the "pragmatic" view, which sees communication as a purposeful sharing of ideas, is a suitable foundation on The opinions of a sample of teachers and instructors on the teaching of communication were surveyed. The survey provided guidance for later developments in the study. It also uncovered concern about assessment charts, the objectives approach and behaviour modification in the education of pupils with severe and profound learning difficulties. A review of programmes and other materials for teaching early communication to the pupils reveals that many of the materials assume that these procedures will be used in teaching. It is suggested that this assumption is a result of perceiving mental handicap as an illness to be treated or cured. A set of draft curriculum materials was compiled on the basis of a simple framework of five stages which trace the development of communication from birth to the two-word stage. The materials were tested in a pilot study which produced recommendations for a revision of the framework and of the materials themselves. The revision was evaluated in an outreach project where it was found to help teachers select appropriate learning activities for their pupils. Throughout the study, there are examples of teachers adapting proposals for the development of curriculum to fit the individual circumstances in which they work daily. The outcome of this personal investment is that professional development and curriculum development complement each other

    Non-fatal self-harm in Scottish military veterans: a retrospective cohort study of 57,000 veterans and 173,000 matched non-veterans

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    Purpose: Although suicide risk in veterans has been widely studied, there is little information on the risk of non-fatal self-harm in this population. We used data from the Scottish Veterans Health Study to conduct an epidemiological analysis of self-harm in veterans, in comparison with people who have never served. Methods: We conducted a retrospective, 30-year cohort study of 56,205 veterans born 1945–1985, and 172,741 people with no record of military service, and used Cox proportional hazard models to examine the association between veteran status and cumulative risk of non-fatal self-harm, overall and stratified by birth cohort, sex and length of service. We also examined mental and physical comorbidities, and association of suicide with prior self-harm. Results: There were 1620 (2.90%) first episodes of self-harm in veterans, compared with 4212 (2.45%) in non-veterans. The difference was statistically significant overall (unadjusted HR 1.27, 95% CI 1.21–1.35, p < 0.001). The risk was highest in the oldest veterans, and in the early service leavers who failed to complete initial training (unadjusted HR 1.69, 95% CI 1.50–1.91, p < 0.001). The risk reduced with longer service and in the intermediate birth cohorts but has increased again in the youngest cohort. Conclusions: The highest risk of non-fatal self-harm was in veterans with the shortest service, especially those who did not complete training or minimum engagement, and in the oldest birth cohorts, whilst those who had served the longest were at reduced risk. The risk has increased again in the youngest veterans, and further study of this subgroup is indicated

    The Influence of Drying Conditions and Other Factors on Twist and Torque in Pinus Radiata Studs

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    Pinus radiata studs of cross section 4 X 1 1/2 inch, sawn to enclose the pith, were dried in conditions of high and low temperatures, high and low air velocities, with and without presteaming, and with and without mechanical restraint. The resultant twist and torque values were measured and it was found that torque developed during drying was negatively correlated with drying rate. The results are interpreted in terms of the elastic-plastic properties of wood during drying. Torque values were used to calculate the equivalent loads required to restrain packs of this timber from twisting during drying and these compared well with optimum loads derived empirically in commercial trials
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