1,029 research outputs found
How to Couple from the Past Using a Read-Once Source of Randomness
We give a new method for generating perfectly random samples from the
stationary distribution of a Markov chain. The method is related to coupling
from the past (CFTP), but only runs the Markov chain forwards in time, and
never restarts it at previous times in the past. The method is also related to
an idea known as PASTA (Poisson arrivals see time averages) in the operations
research literature. Because the new algorithm can be run using a read-once
stream of randomness, we call it read-once CFTP. The memory and time
requirements of read-once CFTP are on par with the requirements of the usual
form of CFTP, and for a variety of applications the requirements may be
noticeably less. Some perfect sampling algorithms for point processes are based
on an extension of CFTP known as coupling into and from the past; for
completeness, we give a read-once version of coupling into and from the past,
but it remains unpractical. For these point process applications, we give an
alternative coupling method with which read-once CFTP may be efficiently used.Comment: 28 pages, 2 figure
Functional Incapacity and Physical and Psychological Symptoms: How They Interconnect in Chronic Fatigue Syndrome
Background: It has been argued that perceived functional incapacity might be a primary characteristic of chronic fatigue syndrome ( CFS) and could be explained by physical symptoms. If so, it could be expected to be closely associated with physical, but not psychological symptoms. The study tests this hypothesis. Sampling and Methods: The sample consisted of 73 patients, with a diagnosis of CFS according to the Oxford criteria, randomly selected from clinics in the Departments of Immunology and Psychiatry at St. Bartholomew's Hospital, London. The degree of fatigue experienced by patients was assessed using the Chalder Fatigue Questionnaire and a visual analogue scale. Self-rated instruments were used to measure physical and social functioning, quality of life, and physical and psychological symptoms. Results: Principal-component analysis of all scale scores revealed 2 distinct components, explaining 53% of the total variance. One component was characterized by psychological symptoms and generic quality of life indicators, whilst the other component was made up of physical symptoms, social and physical functioning and indicators of fatigue. Conclusions: The findings suggest that perceived functional incapacity is a primary characteristic of CFS, which is manifested and/or explained by physical symptoms. Copyright (C) 2008 S. Karger AG, Base
CARDIOVASCULAR EFFECTS OF DILTIAZEM IN THE DOG
SUMMARY The effects of two bolus injections (0.2 mg kg−1) and two infusion rates (0.2 mg min−1 and 0.4 mg min−1) ofdiltiazem on global and regional left (LV) and right ventricular (RV) performance (ultrasonic dimension technique), on coronary (electromagnetic flow meters) and systemic haemodynamics, and on electrophysiology (PR, QRS, QTC intervals) were studied in eight open-chest dogs anaesthetized with droperidol and fentanyl. The two bolus injections of diltiazem resulted in plasma concentrations of 688 ± 115 and 650 ± 85 ng ml−1 (means ± SE), respectively, and caused substantial decreases in systemic and coronary vascular resistances, and in aortic pressure, and increases in LV segment shortening, stroke volume and aortic flow. Electro -physiological variables were little affected. At the low infusion rate (plasma concentration 140 ± 23 ng ml−1) coronary and systemic vaso-dilatation occurred, but global and regional RV and LV performance were little affected. PR interval increased by 15%. At the higher infusion rate (plasma concentration 282 ± 33 ng ml−1) coronary and systemic vasodilatation were maintained. Aortic pressure decreased slightly. Whereas LV end-diastolic and end-systolic dimensions remained unchanged, they increased in the RV. In addition, the PR interval increased by 35%, and three animals developed atrio-ventricular block type I. The data indicate that diltiazem is a potent coronary and systemic vasodilator with little effect on global RV and L V performance. However, at a higher infusion rate RV dimensions clearly tend to increase, and conduction abnormalities develo
Can mental health interventions change social networks? A systematic review
KA was previously funded by East London NHS Foundation Trust, and is a PhD research fellow in the Netherlands at the time of print. SP was funded by Queen Mary University of London, and NL was funded by East London NHS Foundation Trust
How do psychiatrists address delusions in first meetings in acute care? A qualitative study
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Effective patient–clinician interaction to improve treatment outcomes for patients with psychosis: a mixed-methods design
BACKGROUND:At least 100,000 patients with schizophrenia receive care from community mental health teams (CMHTs) in England. These patients have regular meetings with clinicians, who assess them, engage them in treatment and co-ordinate care. As these routine meetings are not commonly guided by research evidence, a new intervention, DIALOG, was previously designed to structure consultations. Using a hand-held computer, clinicians asked patients to rate their satisfaction with eight life domains and three treatment aspects, and to indicate whether or not additional help was needed in each area, with responses being graphically displayed and compared with previous ratings. In a European multicentre trial, the intervention improved patients’ quality of life over a 1-year period. The current programme builds on this research by further developing DIALOG in the UK. RESEARCH QUESTIONS:(1) How can the practical procedure of the intervention be improved, including the software used and the design of the user interface? (2) How can elements of resource-oriented interventions be incorporated into a clinician manual and training programme for a new, more extensive ‘DIALOG+’ intervention? (3) How effective and cost-effective is the new DIALOG+ intervention in improving treatment outcomes for patients with schizophrenia or a related disorder? (4) What are the views of patients and clinicians regarding the new DIALOG+ intervention? METHODS:We produced new software on a tablet computer for CMHTs in the NHS, informed by analysis of videos of DIALOG sessions from the original trial and six focus groups with 18 patients with psychosis. We developed the new ‘DIALOG+’ intervention in consultation with experts, incorporating principles of solution-focused therapy when responding to patients’ ratings and specifying the procedure in a manual and training programme for clinicians. We conducted an exploratory cluster randomised controlled trial with 49 clinicians and 179 patients with psychosis in East London NHS Foundation Trust, comparing DIALOG+ with an active control. Clinicians working as care co-ordinators in CMHTs (along with their patients) were cluster randomised 1 : 1 to either DIALOG+ or treatment as usual plus an active control, to prevent contamination. Intervention and control were to be administered monthly for 6 months, with data collected at baseline and at 3, 6 and 12 months following randomisation. The primary outcome was subjective quality of life as measured on the Manchester Short Assessment of Quality of Life; secondary outcomes were also measured. We also established the cost-effectiveness of the DIALOG intervention using data from the Client Service Receipt Inventory, which records patients’ retrospective reports of using health- and social-care services, including hospital services, outpatient services and medication, in the 3 months prior to each time point. Data were supplemented by the clinical notes in patients’ medical records to improve accuracy. We conducted an exploratory thematic analysis of 16 video-recorded DIALOG+ sessions and measured adherence in these videos using a specially developed adherence scale. We conducted focus groups with patients (n = 19) and clinicians (n = 19) about their experiences of the intervention, and conducted thematic analyses. We disseminated the findings and made the application (app), manual and training freely available, as well as producing a protocol for a definitive trial. RESULTS:Patients receiving the new intervention showed more favourable quality of life in the DIALOG+ group after 3 months (effect size: Cohen’s d = 0.34), after 6 months (Cohen’s d = 0.29) and after 12 months (Cohen’s d = 0.34). An analysis of video-recorded DIALOG+ sessions showed inconsistent implementation, with adherence to the intervention being a little over half of the possible score. Patients and clinicians from the DIALOG+ arm of the trial reported many positive experiences with the intervention, including better self-expression and improved efficiency of meetings. Difficulties reported with the intervention were addressed by further refining the DIALOG+ manual and training. Cost-effectiveness analyses found a 72% likelihood that the intervention both improved outcomes and saved costs. LIMITATIONS:The research was conducted solely in urban east London, meaning that the results may not be broadly generalisable to other settings. CONCLUSIONS:(1) Although services might consider adopting DIALOG+ based on the existing evidence, a definitive trial appears warranted; (2) applying DIALOG+ to patient groups with other mental disorders may be considered, and to groups with physical health problems; (3) a more flexible use with variable intervals might help to make the intervention even more acceptable and effective; (4) more process evaluation is required to identify what mechanisms precisely are involved in the improvements seen in the intervention group in the trial; and (5) what appears to make DIALOG+ effective is that it is not a separate treatment and not a technology that is administered by a specialist; rather, it changes and utilises the existing therapeutic relationship between patients and clinicians in CMHTs to initiate positive change, helping the patients to improve their quality of life. FUTURE RESEARCH:Future studies should include a definitive trial on DIALOG+ and test the effectiveness of the intervention with other populations, such as people with depression. TRIAL REGISTRATION:Current Controlled Trials ISRCTN34757603. FUNDING:The National Institute for Health Research Programme Grants for Applied Research programme
Do long-term hospitalised patients benefit from discharge into the community?
The original publication is available at www.springerlink.co
Symptoms associated with victimization in patients with schizophrenia and related disorders
Background: Patients with psychoses have an increased risk of becoming victims of violence. Previous studies have suggested that higher symptom levels are associated with a raised risk of becoming a victim of physical violence. There has been, however, no evidence on the type of symptoms that are linked with an increased risk of recent victimization. Methods: Data was taken from two studies on involuntarily admitted patients, one national study in England and an international one in six other European countries. In the week following admission, trained interviewers asked patients whether they had been victims of physical violence in the year prior to admission, and assessed symptoms on the Brief Psychiatric Rating Scale (BPRS). Only patients with a diagnosis of schizophrenia or related disorders (ICD-10 F20–29) were included in the analysis which was conducted separately for the two samples. Symptom levels assessed on the BPRS subscales were tested as predictors of victimization. Univariable and multivariable logistic regression models were fitted to estimate adjusted odds ratios. Results: Data from 383 patients in the English sample and 543 patients in the European sample was analysed. Rates of victimization were 37.8% and 28.0% respectively. In multivariable models, the BPRS manic subscale was significantly associated with victimization in both samples. Conclusions: Higher levels of manic symptoms indicate a raised risk of being a victim of violence in involuntary patients with schizophrenia and related disorders. This might be explained by higher activity levels, impaired judgement or poorer self-control in patients with manic symptoms. Such symptoms should be specifically considered in risk assessments
Understanding psychiatric institutionalization: a conceptual review
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
General practice consultations with obese children-a missed opportunity? Cross-sectional study using linked national child measurement and primary care data
Meeting AbstractBackground
A third of children leaving primary school are obese. Child weight status information from the National Child Measurement Programme (NCMP) is not routinely shared with general practitioners (GPs). We hypothesised that obese children were more likely to consult their GP for obesity or weight management than healthy-weight children.
Methods
NCMP data from 2013–16 for City and Hackney, London, were linked to coded GP data using pseudonymised National Health Service numbers, resulting in 13 663 linked records (93%). NCMP-assigned weight status was based on the UK90 clinical reference, and obesity and weight-management consultations identified (read codes C38..; 66C..; 8HHH%; 9N1yK; 22A%). The odds of one or more obesity or weight-management consultations in the school year of NCMP measurement among obese compared with healthy-weight children were estimated with logistic regression.
Findings
Obesity was identified in 624 (8·6%) of 7275 children aged 5 years (3721 boys [51·2%]; median age 5·01 years, IQR 4·76–5·27) and 1220 (19·1%) of 6388 children aged 11 (3297 [51·6%]; 10·87, 10·59–11·11). Obesity was more prevalent in boys than girls (9·5% [353/3721] vs 7·6% [271/3554] and 19·5% [643/3297] vs 18·7% [577/3091] at ages 5 and 11 years, respectively). Obese children were more likely than healthy-weight children to consult for obesity or weight management (respectively at age 5 years, boys 19·8% [70/353] vs 13·5% [391/2900]; girls 16·2% [44/271] vs 11·8% [342/2895] and at age 11 years, boys 17·0% [109/643] vs 12·6% [265/2111]; girls 19·9% [115/577] vs 10·0% [200/1996]). The odds of one or more obesity or weight-management consultations in obese boys and girls, respectively, were 1·59 (95% CI 1·20–2·10) and 1·45 (1·03–2·04) at age 5 years, and 1·42 (1·12–1·81) and 2·24 (1·74–2·87) at age 11 years.
Interpretation
Although more likely to consult their GP for obesity or weight management in the period before or after identification of obesity in the NCMP, fewer than a fifth of obese children attending primary schools in a London borough with one of the highest child obesity rates in England do so. This is, to our knowledge, the first study linking NCMP to primary care data. Further work is needed to evaluate routine sharing of NCMP data with GPs and primary care-initiated weight-management support for children and their families
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