901 resultados para Measures of Contradiction


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The assessment of quality of life (QOL) is necessary to monitor the course of disease and to assess the effect of new and existing interventions in clinical practice. This will only be achieved if QOL can be measured accurately and routinely. The aim of this study was to demonstrate the methodology involved in the adaptation and shortening of the Chronic Respiratory Disease Questionnaire (CRDQ) in a population of adults with cystic fibrosis (CF). A single interviewer administered the CRDQ to a sample of 45 adult patients (32 males) with CF prior to assessment of spirometric measures of lung function. Those patients whose lung function was stable at the time of study, and who could attend for a retest within 14 days, were asked to complete the questionnaire at a subsequent visit (n=10). The average interval between visits was 7 days (range 5-14 days). Correlations between spirometry and CRDQ dimensions ranged from -0.003 to 0.426. The fatigue, emotion and mastery dimensions showed high internal consistency, and adequate construct validity. In the small number of patients suitable for retest, the results indicated that the dimensions exhibited adequate test retest reliability. In contrast low internal consistency was demonstrated for the dyspnoea dimension. The fatigue, emotion and mastery dimensions could be reduced, in terms of their number of items without a substantial loss in explanatory power. This study suggests that QOL measurement can be made convenient, and so more easily accessible for routine clinical assessment.

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In 1999 Stephen Gorard published an article in this journal in which he provided a trenchant critique of what he termed the `politician's error' in analysing differences in educational attainment. The main consequence of this error, he argued, has been the production of misleading findings in relation to trends in educational performance over time that have, in turn, led to misguided and potentially damaging policy interventions. By using gender differences in educational attainment as a case study, this article begins by showing how Gorard's notion of the politician's error has been largely embraced and adopted uncritically by those within the field. However, the article goes on to demonstrate how Gorard's own preferred way of analysing such differences – by calculating and comparing proportionate changes in performance between groups – is also inherently problematic and can lead to the production of equally misleading findings. The article will argue that there is a need to develop a more reliable and valid way of measuring trends in educational performance over time and will show that one of the simplest ways of doing this is to make use of existing, and widely accepted, measures of effect size.

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Latent inhibition (LI) is a measure of reduced learning about a stimulus to which there has been prior exposure without any consequence. It therefore requires a comparison between a pre-exposed (PE) and a non-pre-exposed (NPE) condition. Since, in animals, LI is disrupted by amphetamines and enhanced by antipsychotics, LI disruption has been proposed as a measure of the characteristic attentional deficit in schizophrenia: the inability to ignore irrelevant stimuli. The findings in humans are, however, inconsistent. In particular, a recent investigation suggested that since haloperidol disrupted LI in healthy volunteers, and LI was normal in non-medicated patients with schizophrenia, the previous findings in schizophrenic patients were entirely due to the negative effects of their medication on LI (Williams et al., 1998). We conducted two studies of antipsychotic drug effects on auditory LI using a within-subject, parallel group design in healthy volunteers. In the first of these, single doses of haloperidol (1 mg. i.v.) were compared with paroxetine (20 mg p.o.) and placebo, and in the second, chlorpromazine (100 mg p.o.) was compared with lorazepam (2 mg. p.o.) and placebo. Eye movements, neuropsychological test performance (spatial working memory (SWM), Tower of London and intra/extra dimensional shift, from the CANTAB test battery) and visual analogue rating scales, were also included as other measures of attention and frontal lobe function. Haloperidol was associated with a non-significant reduction in LI scores, and dysphoria/akathisia (Barnes Akathisia Rating Scale) in three-quarters of the subjects. The LI finding may be explained by increased distractibility which was indicated by an increase in antisaccade directional errors in this group. In contrast, LI was significantly increased by chlorpromazine but not by an equally sedative dose of lorazepam (both drugs causing marked decreases in peak saccadic velocity). Paroxetine had no effect on LI, eye movements or CANTAB neuropsychological test performance. Haloperidol was associated with impaired SWM, which correlated with the degree of dysphoria/akathisia, but no other drug effects on CANTAB measures were detected. We conclude that the effect of antipsychotics on LI is both modality and pharmacologically dependent and that further research using a wider range of antipsychotic compounds is necessary to clarify the cognitive effects of these drugs, and to determine whether there are important differences between them.

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The objective of this study was to assess the effectiveness and tolerability of galantamine in patients with mild-to-moderate Alzheimer's disease (AD) in everyday clinical practice. Patient selection was made on 36 sequential patients attending Belfast City Hospital Memory Clinic between December 2000 and June 2001. Patients were treated with galantamine for 6 months, starting from 4 mg twice daily increasing to 8 mg twice daily and then to 12 mg twice daily at 4-weekly intervals. Patients (25 females, 11 males), mean age 78 years (59-90), were diagnosed with probable AD and had a mini-mental state examination (MMSE) score of 10-26. Efficacy was assessed using the MMSE, neuropsychiatric inventory (NPI), neuropsychiatric inventory caregiver distress (NPI-D) scale and the Bristol activities of daily living (B-ADL) scale at baseline and after 3 and 6 months of treatment. Mean improvements were noted on all four measures of efficacy at 3 and 6 months; improvements were significant on the MMSE, NPI and NPI-D at 3 months and on the NPI-D at 6 months. Galantamine was overall well tolerated. The most common adverse events were gastrointestinal, particularly nausea. Four patients stopped treatment due to adverse events, and seven were stabilised on 8 mg twice daily as they were unable to tolerate the target dose. This naturalistic study confirms clinical trial data, which shows galantamine improves cognition and behavioural symptoms and is overall well tolerated. © 2004 Blackwell Publishing Ltd.

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Objective To demonstrate the potential value of screening for Down's Syndrome using highly correlated repeated measures of serum markers taken in the first and second trimesters of pregnancy. Design A Monte Carlo simulation study. Population Detection rates and false positive rates relating to the maternal age distribution of England and Wales for the period 1996 to 1998 were obtained using marker distributions from the SURUSS study. Results Screening using first trimester nuchal translucency and repeated measures of uE3 and PAPP-A in the first and second trimester has an estimated false positive rate of 0.3% for an 85% detection rate. This should be compared with the integrated test with an estimated false positive rate of 1.2% for the same detection rate. Conclusionsâ?? The performance of repeated measures screening tests, and their acceptability to women, should be assessed in further prospective studies.

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Aims: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. Methods: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6x2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). Methods: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. Results: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. Conclusions: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

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The study of alternative combination rules in DS theory when evidence is in conflict has emerged again recently as an interesting topic, especially in data/information fusion applications. These studies have mainly focused on investigating which alternative would be appropriate for which conflicting situation, under the assumption that a conflict is identified. The issue of detection (or identification) of conflict among evidence has been ignored. In this paper, we formally define when two basic belief assignments are in conflict. This definition deploys quantitative measures of both the mass of the combined belief assigned to the emptyset before normalization and the distance between betting commitments of beliefs.We argue that only when both measures are high, it is safe to say the evidence is in conflict. This definition can be served as a prerequisite for selecting appropriate combination rules.

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Primary objective: To compare patients with traumatic brain injury (TBI) with controls on sub-types of aggression and explore the role of social desirability.
Design: Quasi-experimental, matched-participants design.
Methods and procedures: Sixty-nine participants were included in the study. The sample comprised a TBI group (n = 24), a spinal cord injury (SCI) group (n = 21) and an uninjured (UI) group of matched healthy volunteers (n = 24). Participants were given self-report measures of aggression, social desirability and impulsivity. Sixty-one independent ‘other-raters’ were nominated, who rated participant pre-morbid and post-morbid aggression.
Main outcomes and results: Using standardized norms, 25–39% of participants with TBI were classified as high average–very high on anger and 35–38% as high average–very high on verbal aggression. Other-raters rated participants with TBI as significantly higher on verbal aggression than SCI and UI participants. There were no differences between the groups on physical aggression. The TBI group also had higher levels of impulsivity than SCI and UI groups. Social desirability was a highly significant predictor of self-reported aggression for the entire sample.
Conclusions: Impulsive verbal aggression and anger are the principal aggressive traits after brain injury. Physical aggression may present in extreme cases after TBI, but appears less prominent overall in this population. Social desirability, previously overlooked in research examining TBI aggression, emerged as an influential variable that should be considered in future TBI research.

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Measures of entanglement, fidelity, and purity are basic yardsticks in quantum-information processing. We propose how to implement these measures using linear devices and homodyne detectors for continuous-variable Gaussian states. In particular, the test of entanglement becomes simple with some prior knowledge that is relevant to current experiments.

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The long-term impact of dietary carbohydrate type, in particular sucrose, on insulin resistance and the development of diabetes and atherosclerosis is not established. Current guidelines for the healthy population advise restriction of sucrose intake. We investigated the effect of high- versus low-sucrose diet (25 vs. 10%, respectively, of total energy intake) in 13 healthy subjects aged 33 +/- 3 years (mean +/- SE), BMI 26.6 +/- 0.9 kg/m(2), in a randomized crossover design with sequential 6-week dietary interventions separated by a 4-week washout. Weight maintenance, eucaloric diets with identical macronutrient profiles and fiber content were designed. All food was weighed and distributed. Insulin action was assessed using a two-step euglycemic clamp; glycemic profiles were assessed by the continuous glucose monitoring system and vascular compliance by pulse-wave analysis. There was no change in weight across the study. Peripheral glucose uptake and suppression of endogenous glucose production were similar after each diet. Glycemic profiles and measures of vascular compliance did not change. A rise in total and LDL cholesterol was observed. In this study, a high-sucrose intake as part of an eucaloric, weight-maintaining diet had no detrimental effect on insulin sensitivity, glycemic profiles, or measures of vascular compliance in healthy nondiabetic subjects.

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The Northern Hemisphere cooling event 8200 years ago is believed to represent the last known major freshwater pulse into the North Atlantic as a result of the final collapse of the North American Laurentide ice sheet. This pulse of water is generally believed to have occurred independently of orbital variations and provides an analogue for predicted increases in high-latitude precipitation and ice melt as a result of anthropogenically driven future climate change. The precise timing, duration and magnitude of this event, however, are uncertain, with suggestions that the 100-yr meltwater cooling formed part of a longer-term cold period in the early Holocene. Here we undertook a multiproxy, high-resolution investigation of a peat sequence at Dooagh, Achill Island, on the west coast of Ireland, to determine whether the 8200-year cold event impacted upon the terrestrial vegetation immediately downwind of the proposed changes in the North Atlantic. We find clear evidence for an oscillation in the early Holocene using various measures of pollen, indicating a disruption in the vegetation leading to a grassland-dominated landscape, most probably driven by changes in precipitation rather than temperature. Radiocarbon dating was extremely problematic, however, with bulk peat samples systematically too young for the North Atlantic event, suggesting significant contamination from downward root penetration. The sustained disruption to vegetation over hundreds of years at Dooagh indicates the landscape was impacted by a long-term cooling event in the early Holocene, and not the single century length 8200-year meltwater event proposed in many other records in the North Atlantic region.

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Accelerated soil erosion is an aspect of dryland degradation that is affected by repeated intense drought events and land management activities such as commercial livestock grazing. A soil stability index (SSI) that detects the erosion status and susceptibility of a landscape at the pixel level, i.e., stable, erosional, or depositional pixels, was derived from the spectral properties of an archived time series (from 1972 to 1997) of Landsat satellite data of a commercial ranch in northeastern Utah. The SSI was retrospectively validated with contemporary field measures of soil organic matter and erosion status that was surveyed by US federal land management agencies. Catastrophe theory provided the conceptual framework for retrospective assessment of the impact of commercial grazing and soil water availability on the SSI. The overall SSI trend was from an eroding landscape in the early drier 1970s towards stable conditions in the wetter mid-1980s and late 1990s. The landscape catastrophically shifted towards an extreme eroding state that was coincident with the “The Great North American Drought of 1988”. Periods of landscape stability and trajectories toward stability were coincident with extremely wet El Niño events. Commercial grazing had less correlation with soil stability than drought conditions. However, the landscape became more susceptible to erosion events under multiple droughts and grazing. Land managers now have nearly a year warning of El Niño and La Niña events and can adjust their management decisions according to predicted landscape erosion conditions.

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Previous studies have suggested an association between depressed mood and the dietary intake of fish. In all cases, however, dietary fish intake has been considered at the exclusion of all other aspects of the diet. This analysis investigates associations between depressed mood and dietary fish intake, while also concurrently investigating intake of a number of other dietary components. The analysis is conducted on data from 10,602 men from Northern Ireland and France screened for inclusion into the PRIME cohort study. Depressed mood was assessed using a self-report questionnaire based on the Welsh Pure Depression sub-scale of the Minnesota Multiphasic Personality Inventory, diet was assessed using a Food Frequency Questionnaire, and limited demographics were also measured. Using regression, depressed mood is initially inversely associated with dietary fish intake. On inclusion of all other dietary variables, the strength of this relationship reduces but remains, and significant associations with a number of other foods are also found. On additional inclusion of all demographic variables, the strength of the above relationships again reduces, and associations with various measures of socio-economic status and education are also significant. These findings suggest that depressed mood is associated with fish intake both directly, and indirectly as part of a diet that is associated with depression and as part of a lifestyle that is associated with depression. Additional support for these conclusions is also provided in the pattern of associations between depressed mood and diet in the two countries. The relative contributions of fish intake to depressed mood both directly and indirectly are yet to be determined. However, while diet is not measured and until lifestyle can be adequately measured, the potential roles of diet and lifestyle in the association between depressed mood and dietary fish intake should not be ignored.

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The Perceived Health Competence Scale (PHCS) is a measure of self-efficacy regarding general healthrelated behaviour. This brief paper examines the psychometric properties of the PHCS in a UK context. Questionnaires containing the PHCS, the SF-36 and questions about perceived health needs were posted to 486 patients randomly selected from a GP practice list. Complete questionnaires were returned by 320 patients. Analyses of these responses provide strong evidence for the validity of the PHCS in this setting. Consequently, we conclude that the PHCS is a useful addition to measures of global self-efficacy and measures of self-efficacy regarding specific behaviours in the toolkit of health psychologists. This range of self-efficacy assessment tools will ensure that psychologists can match the level of specificity of the measure of expectancy beliefs to the level of specificity of the outcome of interest.

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Objectives: The main objective of this pilot study was to investigate which standardized functional and physiological test best predicted perceived disability in a single group of 21 individuals diagnosed with osteoarthritis of the hip. Design: Men and women between 60 and 70 years old with osteoarthritis of the hip were selected. If participants passed study criteria, the Western Ontario McMaster University questionnaire (WOMAC), 6 Minute Walk Test (6MWT) and Timed up and Go (TUG), strength testing and aerobic testing were obtained in one single assessment. Results: Regression analysis revealed that wait time, hip abduction strength of the affected side, Aerobic Capacity (VO2 Peak), hip Extension Peak Torque, hip Flexion Peak Torque, TUG and 6MWT were significantly correlated with the WOMAC. Yet, the 6MWT had the highest significant correlation (r = -0.86, p ≤ 0.0001); R2 = 0.75 or 75% with the WOMAC total scores, (r = -0.82, p ≤ 0.0001); R2 = 0.67 or 67% with the WOMAC function and (r = -0.60, p = .002); R2 = 0.36 or 36% with the WOMAC stiffness. While the VO2 Peak revealed the highest significant correlation (r = 0.76, p ≤ .0001); R2 = 0.57 or 57% with the WOMAC pain. Conclusions: The 6MWT and the VO2 Peak seem to be essential functional and physiological assessment tools to determine perceived disability in individuals with hip OA. The perceived disability may provide new or comprehensive knowledge of the disability problems experienced by individuals with osteoarthritis of the hip, and the association of patient perception with objective measures of functional and physiological capacity might strengthen the clinical value of this knowledge.