63 research outputs found

    Connecting Winding Codes to Quality Control Devices

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    The goal of this study was to develop an extension to the winding models which can convert the outputs of pressures and stresses to units that can be measured using existing quality control devices, the Rho meter in this case. The Rho meter makes dynamic measurement of the hardness of a wound roll. The peak deceleration of the Rho meter striker is measured and converted into arbitrary "Rho" units, which is a measure of hardness of the wound roll. Initially, experiments were conducted to study the variation of hardness in a wound roll as a function of winding tension and the roll outer radius. Based on the experimental results, a dynamic impact model was developed to simulate the Rho meter. The output obtained from the model was compared to the experimental results. The model made fair predictions of the roll hardness. The material properties vary in time due to the pressures generated by the impact. The explicit method was used in the dynamic analysis since it facilitates the updating of material properties after each solution in time step. Due to this, large computation times are associated with this model. Different algorithms were used to calculate the time step required for the explicit solution and the algorithm employed in this model shows good convergence. The accuracy of the model output increases with an increase in mesh density.Mechanical & Aerospace Engineerin

    Identifying potential moderators for response to treatment in low back pain : a systematic review

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    Background: Identifying which patients with non-specific low back pain are likely to gain the greatest benefit from different treatments is an important research priority. Few studies are large enough to produce data on sub-group effects from different treatments. Data from existing large studies may help identify potential moderators to use in future individual patient data meta-analyses. Objective: To systematically review papers of therapist delivered interventions for low back pain to identify potential moderators to inform an individual patient data meta-analysis. Data sources: We searched MEDLINE, EMBASE, Web of Science and Citation Index and Cochrane Register of Controlled Trials (CENTRALhttp://www.cochrane.org/editorial-and-publishing-policy-resource/cochrane-central-register-controlled-trials-central) for relevant papers. Data extraction and data synthesis: We screened for randomised controlled trials with ≥500 or more participants, and cohort studies of ≥1000 or more participants. We examined all publications related to these studies for any reported moderator analyses. Two reviewers independently did risk of bias assessment of main results and quality assessment of any moderator analyses. Results: We included four randomised trials (n=7208). Potential moderators with strong evidence (p<0.05) in one or more studies were age, employment status and type, back pain status, narcotic medication use, treatment expectations and education. Potential moderators with weaker evidence (0.05<p≤0.20) included gender, psychological distress, pain/disability and quality of life. Conclusion: There are insufficient robust data on moderators to be useful in clinical practice. This review has identified some important potential moderators of treatment effect worthy of testing in future confirmatory analyses

    Is protocolised weaning that includes early extubation onto non-invasive ventilation more cost effective than protocolised weaning without non-invasive ventilation? Findings from the Breathe Study

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    Background Optimising techniques to wean patients from invasive mechanical ventilation (IMV) remains a key goal of intensive care practice. The use of non-invasive ventilation (NIV) as a weaning strategy (transitioning patients who are difficult to wean to early NIV) may reduce mortality, ventilator-associated pneumonia and intensive care unit (ICU) length of stay. Objectives Our objectives were to determine the cost effectiveness of protocolised weaning, including early extubation onto NIV, compared with weaning without NIV in a UK National Health Service setting. Methods We conducted an economic evaluation alongside a multicentre randomised controlled trial. Patients were randomised to either protocol-directed weaning from mechanical ventilation or ongoing IMV with daily spontaneous breathing trials. The primary efficacy outcome was time to liberation from ventilation. Bivariate regression of costs and quality-adjusted life-years (QALYs) provided estimates of the incremental cost per QALY and incremental net monetary benefit (INMB) overall and for subgroups [presence/absence of chronic obstructive pulmonary disease (COPD) and operative status]. Long-term cost effectiveness was determined through extrapolation of survival curves using flexible parametric modelling. Results NIV was associated with a mean INMB of £620 (US885)(cost−effectivenessthresholdof£20,000perQALY)withacorrespondingprobabilityof58US885) (cost-effectiveness threshold of £20,000 per QALY) with a corresponding probability of 58% that NIV is cost effective. The probability that NIV is cost effective was higher for those with COPD (84%). NIV was cost effective over 5 years, with an estimated incremental cost-effectiveness ratio of £4618 (US6594 per QALY gained). Conclusions The probability of NIV being cost effective relative to weaning without NIV ranged between 57 and 59% overall and between 82 and 87% for the COPD subgroup

    Does Structured Exercise Improve Cognitive Impairment in People with Mild to Moderate Dementia? A Cost-Effectiveness Analysis from a Confirmatory Randomised Controlled Trial:The Dementia and Physical Activity (DAPA) Trial

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    Background Previous studies suggest that physical exercise could slow dementia progression. However, evidence for the cost effectiveness of structured exercise is conflicting and based on small trials. Objectives The objective of this study was to compare the cost effectiveness of a tailored, structured, moderate- to high-intensity exercise programme versus usual care in people with mild to moderate dementia. Methods An economic evaluation was conducted from the UK National Health Service and personal social services perspective, based on data from a large randomised controlled trial. The primary clinical outcome was the participant reported ADAS-Cog (Alzheimer’s Disease Assessment Scale–Cognitive Subscale) at 12 months. Costs (£; 2014–2015 prices) were collected prospectively over a 12-month follow-up period. A bivariate regression of costs and quality-adjusted life-years (QALYs), with multiple imputation of missing data, was conducted with the view to estimating the incremental cost per QALY gained and the incremental net monetary benefit (INMB) associated with the exercise programme plus usual care versus usual care. Sensitivity analyses were undertaken to assess the impact of uncertainty surrounding aspects of the economic evaluation, and pre-specified subgroup analyses explored heterogeneity in the cost-effectiveness results. Results Participants (n = 494) were randomised to exercise plus usual care or usual care only. By 12 months the mean ADAS-Cog score had worsened slightly to 25.2 (standard deviation [SD] 12.3) in the exercise arm and 23.8 (SD 10.4) in the usual care: difference − 1.4, 95% confidence interval (CI) − 2.6 to − 0.2 (p = 0.03). The mean (standard error [SE]) costs over 12 months for experimental versus control was £5945 (USD7856) versus £4597 (USD6574), respectively; (difference: £1347 [$1926]; p = 0.0426). Mean (SE) QALY estimates were 0.787 (0.012) versus 0.826 (0.019), respectively (p = 0.090). The probability that the exercise programme is cost effective was  Conclusions Building on the clinical results of the trial, which showed that the structured exercise programme evaluated does not slow cognitive impairment in people with mild to moderate dementia, this economic evaluation shows that the programme is not cost effective.</p

    A protocol for a feasibility randomised controlled trial to assess the difference between functional bracing and plaster cast for the treatment of ankle fractures

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    Background: UK Hospital Episode Statistics 2013–2014 recorded 57,286 fractures of the lower limb including the ankle. This figure is expected to continue to increase due to a greater population of older adults. Following an ankle fracture, patients usually have their ankle immobilised with a plaster cast. This provides maximum support for the healing ankle but is associated with stiffness and muscle wasting. A Cochrane Review has concluded that functional bracing may reduce muscle wasting and speed recovery of ankle movement. The aim of this study is to determine the feasibility of conducting a full randomised controlled trial in adults with an ankle fracture followed by functional bracing and exercises versus standard plaster cast care. Methods: This is a single-centre feasibility randomised controlled trial. All patients with a fractured ankle are potentially eligible. The trial will employ 1:1 random allocation, stratified by age and non-operative/operative management. Baseline demographic and pre-injury functional data, the Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) and Olerud and Molander Ankle Score (OMAS) will be collected alongside the EuroQol EQ-5D-5 L health-related quality of life questionnaire. A research associate will perform a clinical assessment and obtain X-rays in 6 weeks and 6 months post randomisation to record complications. Functional outcome and health-related quality of life will be collected in 6 weeks, 3 and 6 months post randomisation. Discussion: This feasibility trial will provide authoritative high-quality evidence to inform the design of a definitive trial in this important area

    Psychiatric hospital reform in low-income and middle-income countries Structured Individualised inTervention And Recovery (SITAR) : a two-arm pragmatic randomised controlled trial study protocol

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    Introduction Low-income and middle-income settings like India have large treatment gaps in mental healthcare. People with severe mental disorders face impediments to their clinical and functional recovery, and have large unmet needs. The infrastructure and standards of care are poor in colonial period psychiatric hospitals, with no clear pathways to discharge and successfully integrate recovered individuals into the community. Our aim is to study the impact of psychiatric hospital reform on individual patient outcomes in a psychiatric hospital in India. Methods and analysis Structured Individualised inTervention And Recovery (SITAR) is a two-arm pragmatic randomised controlled trial, focusing on patients aged 18–60 years with a hospital stay of 12–120 months and a primary diagnosis of psychosis. It tests the effectiveness of structural and process reform with and without an individually tailored recovery plan on patient outcomes of disability (primary outcome WHO Disability Assessment Scale), symptom severity, social and occupational functioning and quality of life. A computer-generated permuted block randomisation schedule will allocate recruited subjects to the two study arms. We aim to recruit 100 people into each trial arm. Baseline and outcome measures will be undertaken by trained researchers independent to the case managers providing the individual intervention. A health economic analysis will determine the costing of implementing the individually tailored recovery plan

    Dementia and physical activity (DAPA) trial of moderate to high intensity exercise training for people with dementia : randomised controlled trial

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    Objective: To estimate the effect of a moderate to high intensity aerobic and strength exercise training programme on cognitive impairment and other outcomes in people with mild to moderate dementia. Design: Multicentre, pragmatic, investigator masked, randomised controlled trial. Setting: National Health Service primary care, community and memory services, dementia research registers, and voluntary sector providers in 15 English regions. Participants: 494 people with dementia: 329 were assigned to an aerobic and strength exercise programme and 165 were assigned to usual care. Random allocation was 2:1 in favour of the exercise arm. Interventions: Usual care plus four months of supervised exercise and support for ongoing physical activity, or usual care only. Interventions were delivered in community gym facilities and NHS premises. Main outcome measures: The primary outcome was score on the Alzheimer’s disease assessment scale-cognitive subscale (ADAS-cog) at 12 months. Secondary outcomes included activities of daily living, neuropsychiatric symptoms, health related quality of life, and carer quality of life and burden. Physical fitness (including the six minute walk test) was measured in the exercise arm during the intervention. Results: The average age of participants was 77 (SD 7.9) years and 301/494 (61%) were men. By 12 months the mean ADAS-cog score had increased to 25.2 (SD 12.3) in the exercise arm and 23.8 (SD 10.4) in the usual care arm (adjusted between group difference −1.4, 95% confidence interval −2.6 to −0.2, P=0.03). This indicates greater cognitive impairment in the exercise group, although the average difference is small and clinical relevance uncertain. No differences were found in secondary outcomes or preplanned subgroup analyses by dementia type (Alzheimer’s disease or other), severity of cognitive impairment, sex, and mobility. Compliance with exercise was good. Over 65% of participants (214/329) attended more than three quarters of scheduled sessions. Six minute walking distance improved over six weeks (mean change 18.1 m, 95% confidence interval 11.6 m to 24.6 m). Conclusion: A moderate to high intensity aerobic and strength exercise training programme does not slow cognitive impairment in people with mild to moderate dementia. The exercise training programme improved physical fitness, but there were no noticeable improvements in other clinical outcomes

    Moderators of cognitive outcomes from an exercise programme in people with mild to moderate dementia

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    BACKGROUND/OBJECTIVES: Our aim was to estimate whether baseline participant variables were able to moderate the effect of an exercise intervention on cognition in patients with mild to moderate dementia. DESIGN: Subgroup analysis of a multicenter pragmatic randomized controlled trial. SETTING: Community-based gym/rehabilitation centers. PARTICIPANTS: A total of 494 community-dwelling participants with mild to moderate dementia. INTERVENTION: Participants were randomized to a moderate- to high-intensity aerobic and strength exercise program or a usual care control group. Experimental group participants attended twice weekly 60- to 90-minute gym sessions for 4 months. Participants were prescribed home exercises for an additional hour per week during the supervised period and 150 minutes each week after the supervised period. MEASUREMENTS: Multilevel regression model analyses were undertaken to identify individual moderators of cognitive function measured through the Alzheimer Disease Assessment Scale-Cognitive Subscale score at 12 months. RESULTS: When tested for a formal interaction effect, only cognitive function assessed by the baseline number cancellation test demonstrated a statistically significant interaction effect (−2.7 points; 95% confidence interval = −5.14 to −0.21). CONCLUSION: People with worse number cancellation test scores may experience greater progression of cognitive decline in response to a moderate- to high-intensity exercise program. Further analyses to examine whether these findings can be replicated in planned sufficiently powered analyses are indicated

    The effects of supported employment interventions in populations of people with conditions other than severe mental health : a systematic review

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    To assess the effectiveness of supported employment interventions for improving competitive employment in populations of people with conditions other than only severe mental illness. Supported employment interventions have been extensively tested in severe mental illness populations. These approaches may be beneficial outside of these populations. We searched PubMed, Embase, CINAHL, PsycInfo, Web of Science, Scopus, JSTOR, PEDro, OTSeeker, and NIOSHTIC for trials including unemployed people with any condition and including severe mental illness if combined with other co-morbidities or other specific circumstances (e.g., homelessness). We excluded trials where inclusion was based on severe mental illness alone. Two reviewers independently assessed risk of bias (RoB v2.0) and four reviewers extracted data. We assessed rates of competitive employment as compared to traditional vocational rehabilitation or waiting list/services as usual. Ten randomised controlled trials (913 participants) were included. Supported employment was more effective than control interventions for improving competitive employment in seven trials: in people with affective disorders [risk ratio (RR) 10.61 (1.49, 75.38)]; mental disorders and justice involvement [RR 4.44 (1.36,14.46)]; veterans with posttraumatic stress disorder (PTSD) [RR 2.73 (1.64, 4.54)]; formerly incarcerated veterans [RR 2.17 (1.09, 4.33)]; people receiving methadone treatment [RR 11.5 (1.62, 81.8)]; veterans with spinal cord injury at 12 months [RR 2.46 (1.16, 5.22)] and at 24 months [RR 2.81 (1.98, 7.37)]; and young people not in employment, education, or training [RR 5.90 (1.91-18.19)]. Three trials did not show significant benefits from supported employment: populations of workers with musculoskeletal injuries [RR 1.38 (1.00, 1.89)]; substance abuse [RR 1.85 (0.65, 5.41)]; and formerly homeless people with mental illness [RR 1.55 (0.76, 3.15)]. Supported employment interventions may be beneficial to people from more diverse populations than those with severe mental illness alone. Defining competitive employment and increasing (and standardising) measurement of non-vocational outcomes may help to improve research in this area

    Protocolised non-invasive compared with invasive weaning from mechanical ventilation for adults in intensive care : the Breathe RCT

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    Background: Invasive mechanical ventilation (IMV) is a life-saving intervention. Following resolution of the condition that necessitated IMV, a spontaneous breathing trial (SBT) is used to determine patient readiness for IMV discontinuation. In patients who fail one or more SBTs, there is uncertainty as to the optimum management strategy. Objective: To evaluate the clinical effectiveness and cost-effectiveness of using non-invasive ventilation (NIV) as an intermediate step in the protocolised weaning of patients from IMV. Design: Pragmatic, open-label, parallel-group randomised controlled trial, with cost-effectiveness analysis. Setting: A total of 51 critical care units across the UK. Participants: Adult intensive care patients who had received IMV for at least 48 hours, who were categorised as ready to wean from ventilation, and who failed a SBT. Interventions: Control group (invasive weaning): patients continued to receive IMV with daily SBTs. A weaning protocol was used to wean pressure support based on the patient’s condition. Intervention group (non-invasive weaning): patients were extubated to NIV. A weaning protocol was used to wean inspiratory positive airway pressure, based on the patient’s condition. Main outcome measures: The primary outcome measure was time to liberation from ventilation. Secondary outcome measures included mortality, duration of IMV, proportion of patients receiving antibiotics for a presumed respiratory infection and health-related quality of life. Results: A total of 364 patients (invasive weaning, n = 182; non-invasive weaning, n = 182) were randomised. Groups were well matched at baseline. There was no difference between the invasive weaning and non-invasive weaning groups in median time to liberation from ventilation {invasive weaning 108 hours [interquartile range (IQR) 57–351 hours] vs. non-invasive weaning 104.3 hours [IQR 34.5–297 hours]; hazard ratio 1.1, 95% confidence interval [CI] 0.89 to 1.39; p = 0.352}. There was also no difference in mortality between groups at any time point. Patients in the non-invasive weaning group had fewer IMV days [invasive weaning 4 days (IQR 2–11 days) vs. non-invasive weaning 1 day (IQR 0–7 days); adjusted mean difference –3.1 days, 95% CI –5.75 to –0.51 days]. In addition, fewer non-invasive weaning patients required antibiotics for a respiratory infection [odds ratio (OR) 0.60, 95% CI 0.41 to 1.00; p = 0.048]. A higher proportion of non-invasive weaning patients required reintubation than those in the invasive weaning group (OR 2.00, 95% CI 1.27 to 3.24). The within-trial economic evaluation showed that NIV was associated with a lower net cost and a higher net effect, and was dominant in health economic terms. The probability that NIV was cost-effective was estimated at 0.58 at a cost-effectiveness threshold of £20,000 per quality-adjusted life-year. Conclusions: A protocolised non-invasive weaning strategy did not reduce time to liberation from ventilation. However, patients who underwent non-invasive weaning had fewer days requiring IMV and required fewer antibiotics for respiratory infections. Future work: In patients who fail a SBT, which factors predict an adverse outcome (reintubation, tracheostomy, death) if extubated and weaned using NIV? Trial registration: Current Controlled Trials ISRCTN15635197. Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 48. See the NIHR Journals Library website for further project information
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