170 research outputs found
Erectile dysfunction as a predictor for subsequent atherosclerotic cardiovascular events: Findings from a linked-data study
No full textKew-Kim Chew, Judith Finn, Bronwyn Stuckey, Nicholas Gibson, Frank Sanfilippo, Alexandra Bremner, Peter Thompson, Michael Hobbs and Konrad Jamrozi
Comparison of multiple and novel measures of dietary glycemic carbohydrate with insulin resistant status in older women
Get PDFAbstract Background Previous epidemiological investigations of associations between dietary glycemic intake and insulin resistance have used average daily measures of glycemic index (GI) and glycemic load (GL). We explored multiple and novel measures of dietary glycemic intake to determine which was most predictive of an association with insulin resistance. Methods Usual dietary intakes were assessed by diet history interview in women aged 42-81 years participating in the Longitudinal Assessment of Ageing in Women. Daily measures of dietary glycemic intake (n = 329) were carbohydrate, GI, GL, and GL per megacalorie (GL/Mcal), while meal based measures (n = 200) were breakfast, lunch and dinner GL; and a new measure, GL peak score, to represent meal peaks. Insulin resistant status was defined as a homeostasis model assessment (HOMA) value of >3.99; HOMA as a continuous variable was also investigated. Results GL, GL/Mcal, carbohydrate (all P Conclusion A dietary pattern with high peaks of GL above the individual's average intake was a significant independent predictor of insulin resistance in this population, however the contribution was less than daily GL and carbohydrate variables. Accounting for energy intake slightly increased the predictive ability of GL, which is potentially important when examining disease risk in more diverse populations with wider variations in energy requirements.</p
Training to Enhance Psychiatrist Communication with patients with Psychosis (TEMPO): A Cluster Randomized Controlled Trial
Get PDFThis is the author accepted manuscript. The final version is available from the Royal College of Psychiatrists via the DOI in this record.Background: A better therapeutic relationship predicts better outcomes. However, there is no trial based evidence on how to improve therapeutic relationships in psychosis.
Aims: To test the effectiveness of communication training for psychiatrists on improving shared understanding and the therapeutic relationship.
Methods: In a cluster randomized controlled trial in the U.K., 21 psychiatrists were randomized. 97 (51% of those approached) outpatients with schizophrenia/schizoaffective disorder were recruited. 64 (66% of the sample recruited at baseline) were followed up after 5 months. The intervention group received four group and one individualized session. The primary outcome, rated blind, was psychiatrist effort in establishing shared understanding, self-repair. Secondary outcome was the therapeutic relationship.
Results: Psychiatrists receiving the intervention used 44% more self-repair than the control group (6.4, 95% CI 1.46 to 11.33, p<.011, a large effect) adjusting for baseline self-repair. Psychiatrists rated the therapeutic relationship more positively (0.20, 95%CI 0.03 to 0.37, p=.022, a large effect), as did patients (0.21, 95% CI 0.01 to 0.41, p=.043, a medium effect).
Conclusions: Shared understanding can be successfully targeted in training and improves relationships in treating psychosis.
Trial Registration: Current Controlled Trials ISRCTN94846422National Institute for Health Research (NIHR
Two- to Eight-Month-Old Infants' Perception of Dynamic Auditory-Visual Spatial Colocation
Get PDFFrom birth, infants detect associations between the locations of static visual objects and sounds they emit, but there is limited evidence regarding their sensitivity to the dynamic equivalent when a sound-emitting object moves. In 4 experiments involving thirty-six 2-month-olds, forty-eight 5-month-olds, and forty-eight 8-month-olds, we investigated infants' ability to process this form of spatial colocation. Whereas there was no evidence of spontaneous sensitivity, all age groups detected a dynamic colocation during habituation and looked longer at test trials in which sound and sight were dislocated. Only 2-month-olds showed clear sensitivity to the dislocation relation, although 8-month-olds did so following additional habituation. These results are discussed relative to the intersensory redundancy hypothesis and work suggesting increasing specificity in processing with age
Localised splitting criteria for classification and regression trees
No full textThis thesis presents a modification of existing entropy-based splitting criteria for classification and regression trees. Trees are typically grown using splitting criteria that choose optimal splits without taking future splits into account. This thesis examines localised splitting criteria that are based on local averaging in regression trees or local proportions in classification trees. The use of a localised criterion is motivated by the fact that future splits result in leaves that contain local observations, and hence local deviances provide a better approximation of the deviance of the fully grown tree. While most recent research has focussed on tree-averaging techniques that are aimed at taking a moderately successful splitting criterion and improving its predictive power, this thesis concentrates on improving the splitting criterion.
Use of a localised splitting criterion captures local structures and enables later splits to capitalise on the placement of earlier splits when growing a tree. Using the localised splitting criterion results in much simpler trees for pure interaction data (data with no main effects) and can produce trees with fewer errors and lower residual mean deviances than those produced using a global splitting criterion when applied to real data sets with strong interaction effects.
The superiority of the localised splitting criterion can persist when multiple trees are grown and averaged using simple methods. Although a single tree grown using the localised splitting criterion can outperform tree averaging using the global criterion, generally improvements in predictive performance are achieved by utilising the localised splitting criterion's property of detecting local discontinuities and averaging over sets of trees grown by placing splits where the deviance is locally minimal. Predictive performance improves further when the degree of localisation of the splitting criterion is randomly selected and weighted randomisation is used with locally minimal deviances to produce sets of trees to average over. Although state of the art methods quickly average very large numbers of trees, thus making the performance of the splitting criterion less critical, predictive performance when the localised criterion is used in bagging indicates that different splitting methods warrant investigation.
The localised splitting criterion is most useful for growing one tree or a small number of trees to examine structure in the data. Structurally different trees can be obtained by simply splitting the data where the localised splitting criterion is locally optimal
Techniques to monitor for endophthalmitis and other cataract surgery complications
Get PDFObjective: To report complication incidence to identify outliers more reliably, to provide feedback on performance, and to generate more timely alerts.
Design: Data from a retrospective entire-population study was used as an example for the charting methods.
Participants: The Western Australian (WA) Data Linkage System identified all cataract or lens-related procedures undertaken in WA and those operations complicated with endophthalmitis over 20 years from 1980.
Methods: Use of risk-adjusted charts to assess complication incidence between hospitals. We compare these with ones that demonstrate individual hospital performance. The latter also adjust for risk and enable reporting at the time of complication rather than after a data collection period.
Main Outcome Measure: Excessive complication risk (postoperative endophthalmitis).
Results: Confidence limits allow comparison of hospitals performing different numbers of operations; the 95% Poisson prediction interval was exceeded by 4 possible-outlier hospitals. Case-mix risk adjustment better narrowed them to probable outliers (now only 2 hospitals). However, 2 high-volume nonoutlier hospitals had a short duration of significantly higher risk of endophthalmitis with cumulative sum analysis. Their endophthalmitis numbers were not excessive, and they were not identified as outliers by the other methods.
Conclusion: Simple ranking (or league) tables are not useful enough; someone is always first and last. Chance and circumstance will push all towards the middle with time. Risk-adjusted observed versus expected charting better identifies outliers than a funnel plot. Better still, the use of cumulative sum analysis can help surgeons distinguish between failures due to random processes and those that are associated with problems that require investigation to search for potentially correctable causes
Evaluation of paediatric nursing-sensitive outcomes in an Australian population using linked administrative hospital data
Get PDFBackground: Research into nursing-sensitive outcomes using administrative health data has focussed on hospitalised adults. However, we developed algorithms for the identification of 13 paediatric nursing-sensitive outcomes, which we seek to examine for clinical utility. The aims were to determine the rates of paediatric nursing-sensitive outcomes in a Western Australian hospital and ascertain sociodemographic and clinical characteristics associated with a greater risk of developing nursing-sensitive outcomes in hospitalised children.Method: A retrospective cohort study used linked administrative data of all Western Australian children 100 events over the 10 year study period) to be potentially useful for monitoring the quality of nursing care. These nursing-sensitive outcomes are: LRTI, GI infection, pneumonia, surgical wound infection, physiologic/metabolic derangement, sepsis and postoperative cardiopulmonary complications. When used for quality improvement or to benchmark with other agencies, data need to be adjusted for, or stratified by age and admission type, to ensure equitable comparisons
Glycaemic index and glycaemic load intake patterns in older Australian women
No full textAims: Dietary glycemic index (GI) and glycemic load (GL) have been associated with risk of chronic diseases, yet limited research exists on patterns of consumption in Australia. Our aims were to investigate glycemic carbohydrate in a population of older women, identify major contributing food sources, and determine low, moderate and high ranges. \ud
Methods: Subjects were 459 Brisbane women aged 42-81 years participating in the Longitudinal Assessment of Ageing in Women. Diet history interviews were used to assess usual diet and results were analysed into energy and macronutrients using the FoodWorks dietary analysis program combined with a customised GI database. \ud
Results: Mean±SD dietary GI was 55.6±4.4% and mean dietary GL was 115±25. A low GI in this population was ≤52.0, corresponding to the lowest quintile of dietary GI, and a low GL was ≤95. GI showed a quadratic relationship with age (P=0.01), with a slight decrease observed in women aged in their 60’s relative to younger or older women. GL decreased linearly with age (P<0.001). Bread was the main contributor to carbohydrate and dietary GL (17.1% and 20.8%, respectively), followed by fruit (15.5% and 14.2%), and dairy for carbohydrate (9.0%) or breakfast cereals for GL (8.9%). \ud
Conclusions: In this population, dietary GL decreased with increasing age, however this was likely to be a result of higher energy intakes in younger women. Focus on careful selection of lower GI items within bread and breakfast cereal food groups would be an effective strategy for decreasing dietary GL in this population of older women. \ud
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The contribution of visual and vestibular information to spatial orientation by 6- to 14-month-old infants and adults
Get PDFAlthough there is much research on infants' ability to orient in space, little is known regarding the information they use to do so. This research uses a rotating room to evaluate the relative contribution of visual and vestibular information to location of a target following bodily rotation. Adults responded precisely on the basis of visual flow information. Seven-month-olds responded mostly on the basis of visual flow, whereas 9-month-olds responded mostly on the basis of vestibular information, and 12-month-olds responded mostly on the basis of visual information. Unlike adults, infants of all ages showed partial influence by both modalities. Additionally, 7-month-olds were capable of using vestibular information when there was no visual information for movement or stability, and 9-month-olds still relied on vestibular information when visual information was enhanced. These results are discussed in the context of neuroscientific evidence regarding visual-vestibular interaction, and in relation to possible changes in reliance on visual and vestibular information following acquisition of locomotion
One- and Two-Variable -adic Measures in Iwasawa Theory
Get PDFabstract: In 1984, Sinnott used -adic measures on to give a new proof of the Ferrero-Washington Theorem for abelian number fields by realizing -adic -functions as (essentially) the -transform of certain -adic rational function measures. Shortly afterward, Gillard and Schneps independently adapted Sinnott's techniques to the case of -adic -functions associated to elliptic curves with complex multiplication (CM) by realizing these -adic -functions as -transforms of certain -adic rational function measures. The results in the CM case give the vanishing of the Iwasawa -invariant for certain -extensions of imaginary quadratic fields constructed from torsion points of CM elliptic curves.
In this thesis, I develop the theory of -adic measures on , with particular interest given to the case of . Although I introduce these measures within the context of -adic integration, this study includes a strong emphasis on the interpretation of -adic measures as -adic power series. With this dual perspective, I describe -adic analytic operations as maps on power series; the most important of these operations is the multivariate -transform on -adic measures.
This thesis gives new significance to product measures, and in particular to the use of product measures to construct measures on from measures on . I introduce a subring of pseudo-polynomial measures on which is closed under the standard operations on measures, including the -transform. I obtain results on the Iwasawa-invariants of such pseudo-polynomial measures, and use these results to deduce certain continuity results for the -transform. As an application, I establish the vanishing of the Iwasawa -invariant of Yager's two-variable -adic -function from measure theoretic considerations.Dissertation/ThesisDoctoral Dissertation Mathematics 201
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