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1.
Much of the literature on the value of life is based on the valuation of small reductions in mortality risk with many remaining life years if the fatal outcome is avoided. In contrast, this paper explores valuations of interventions which with varying probability levels offer smaller or moderate life year health gains. We interviewed 2900 respondents about hypothetical therapies that involved life year gains in the range of 1-180 months with a probability of 1 to 1/180, presented both in individual and societal perspectives. The results of the study indicate that the value of the hypothetical treatments is not a simple function of probability and gain. Rather, respondents seem to adopt thresholds when they value treatment offers. This results in kinked utility functions where the expected individual utility is significantly decreased when the gain in life expectancy is 6 months or less, and markedly increased if the probability of gains exceeds 1/12. There were only small differences in valuations across the individual and societal perspectives, suggesting that preferences for dispersion of health gains are not only a reflection of equity considerations. If the results of this study reflect widespread preferences, the standard methods in cost-effectiveness/cost-utility analysis may misinform decision makers.  相似文献   

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Hospital‐acquired malnutrition is universally present across the globe. Little progress has been made on overcoming hospital‐acquired malnutrition despite known presence for at least 40 years. Technologies and methods to deliver the recommended calories and protein are available in most healthcare settings. Despite this, inadequate nutrient delivery continues to be a problem. Correia and colleagues propose a simplified algorithm that assists clinicians in becoming aware of poor nutrient intake and suggest nutrition interventions.  相似文献   

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In the analysis of multivariate failure-time data, the effect of a treatment or an exposure on the hazard of each failure type is sometimes evaluated using only the information on the first event that occurs in every individual, ignoring all events that follow. A Cox proportional hazards model may be fitted to such data, yielding a cause-specific hazard ratio (HR) estimate of the exposure for each failure type conditional on surviving all other failure types. However, such an estimate would not fully utilize all the available information on event times. Alternatively, a marginal approach may be implemented to model the time distribution of each failure type beyond the subject's first failure to (any) second and later failures. We investigate the performance of these two approaches by simulating positive and negative correlated event times from exponential distributions. Surprisingly, our results suggest that the first-event-only method (when multiple failures are possible) performs as well as the marginal method in most practical situations. Generally, for a modest sample size of 400, it is possible to achieve at least 85 per cent coverage of the true marginal HR with the first-event method. Although the coverage is poor for a correlation of 0.7 and beyond, such a high correlation between competing event times may be biologically rather implausible.  相似文献   

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OBJECTIVE: To assess the effectiveness of a clinical guidelines-informed multidisciplinary work-related activity program, and to improve the physical, psychological and occupational functioning of chronic pain-disabled injured workers. DESIGN: An uncontrolled, repeated-measures, pilot study was conducted. SETTING: The intervention was delivered in a community setting in regional New South Wales. PARTICIPANTS: Participants (n = 30), mean age of 41 years, had a compensable musculoskeletal injury: 60% were male, 63% had back injuries; the mean time off work was 13 months. INTERVENTION: A cognitive-behavioural, interdisciplinary intervention was delivered using a multi-contributor provider model (a clinical psychologist and physiotherapist from separate practices, working in liaison with the participant's occupational rehabilitation provider and treating doctor). Groups of six participants attended for one half day per week for six weeks. MAIN OUTCOME MEASURES: The outcome measures included: physical functioning, pain intensity and psychological variables, which were assessed pre- and post-program; and medical certification and work participation, which was recorded pre-program and at six-month follow up. RESULTS: Significant gains were made in pain intensity, physical and psychological functioning, and medical certification. The mean effect size of the intervention was medium to large (d = 0.70). There was no significant change in employment status at six-month follow up. CONCLUSIONS: The results of this pilot study suggest that independent, rural or community-based practitioners, working collaboratively using an integrated treatment program, can produce positive outcomes for pain-disabled injured workers, and achieve results similar to those reported by metropolitan-based pain clinics.  相似文献   

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Before an active compound can be registered as a drug, it needs to be demonstrated that it does not cause particular unwanted compound specific side effects. Demonstrating non-inferiority of an active drug with placebo with respect to an unwanted side effect is often based on pharmacodynamic 3 x 3 cross-over trials, with the third treatment arm consisting of a positive control. The main comparison then is the pairwise comparison between active drug and placebo. In this paper, two different non-parametric methods with adjustment for period effect are compared with the non-parametric non-adjusted test and the parametric period-adjusted test with respect to size and power. The non-parametric test with period adjustment based on rank alignment has generally the largest power, but its size exceeds the nominal significance level. The non-parametric test with period adjustment based on stratification has low power for trials with a small number of subjects. The non-parametric test without period adjustment is a valid alternative in such cases, but its power decreases substantially in the presence of period effects. In the case of unbalanced designs, however, only the non-parametric test with period adjustment based on stratification can be used.  相似文献   

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BACKGROUND: Farm‐to‐School programs (FTSPs) connect schools with locally grown food. This article examines whether FTSPs are more common in public elementary schools (ESs) in states with a formal, FTSP law or with a related, locally grown procurement law. METHODS: A pooled, cross‐sectional analysis linked nationally representative samples of 1872 public ESs (across 47 states) for the 2006–2007, 2007–2008, and 2008–2009 school years with state laws effective as of the beginning of September of each year that were collected and analyzed for all states. Multivariate logistic regression models examined the impact of state law on school FTSP participation, controlling for year and school‐level race/ethnicity, region, locale, free‐reduced lunch participation, and school size. RESULTS: The percentage of schools located in a state with a FTSP‐specific law increased from 7.3% to 20.4% over the 3‐year period, while the percentage of schools located in a state with a locally grown procurement law was approximately 30% across all years. The percentage of schools with FTSPs has more than tripled over the last 3 years (from 4.9% to 17.7%). After adjusting for all covariates except year, FTSPs were significantly more likely in states with a FTSP‐specific law (OR = 2.45, 95% CI = 1.28‐4.67); once adjusting for year, the results were marginally significant (OR = 1.72, 95% CI = .91‐3.25). School‐level FTSPs were not related to state locally grown procurement laws. CONCLUSION: Although the percentage of schools with FTSPs is relatively small, these programs are becoming more common, particularly in states with FTSP‐specific laws.  相似文献   

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This paper explores and critically discusses some of the methodological limitations of using the number-needed-to-treat (NNT) in economic evaluation. We argue that NNT may be a straightforward measure of benefit when the effect of an intervention is immediate, but that serious problems arise when the effect is delay rather than avoidance of an adverse event. In this case, NNT is not a robust or accurate measure of effect, but will vary considerably and inconsistently over time. This weakness will naturally spill over onto any CEA based on NNT. A literature review demonstrated that CEAs based on NNT were all published within the last five years, and that all studies suffered from important limitations. A major weakness of using NNT is the imposed restrictions on the outcome measure, which can only be strictly uni-dimensional and non-generic. Using NNT in economic evaluations is obtained at a cost in terms of both methodological shortcomings, and a reduced ability for such evaluations to serve as a useful tool in decision making processes. The use of NNT in economic evaluations might be better avoided.To every complicated question, there is a simple, straightforward, easy--and probably wrong answer (Occam's Sledgehammer).  相似文献   

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An extensive literature has established that it is common for respondents to ignore attributes of the alternatives within choice experiments. In most of the studies on attribute non‐attendance, it is assumed that respondents consciously (or unconsciously) ignore one or more attributes of the alternatives, regardless of their levels. In this paper, we present a new line of enquiry and approach for modelling non‐attendance in the context of investigating preferences for health service innovations. This approach recognises that non‐attendance may not just be associated with attributes but may also apply to the attribute's levels. Our results show that respondents process each level of an attribute differently: while attending to the attribute, they ignore a subset of the attribute's levels. In such cases, the usual approach of assuming that respondents either attend to the attribute or not, irrespective of its levels, is erroneous and could lead to misguided policy recommendations. Our results indicate that allowing for attribute‐level non‐attendance leads to substantial improvements in the model fit and has an impact on estimated marginal willingness to pay and choice predictions.Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

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This article describes how a British Nutrition Foundation Drummond Pump Priming Award was used to develop in vivo proof of concept for increasing colonic propionate as a therapeutic strategy to reduce liver fat in adults with non‐alcoholic fatty disease (NAFLD). An overview of how the gut‐derived short‐chain fatty acids propionate and acetate are taken up and metabolised by the liver is provided, as well as a summary of how acetate may have contrasting effects on hepatic lipid content depending on the metabolic health of the individual. Finally, the article proposes that raising colonic propionate production could interfere with hepatic acetate metabolism and have positive effects on liver fat accumulation in individuals with NAFLD.  相似文献   

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Alcohol misuse in the United Kingdom’s veteran community is not an isolated phenomenon. Internationally, alcohol and wider substance misuse would appear to be an historic and current global issue within veteran communities. Although research has been undertaken both in the United Kingdom and the United States into why veterans are reluctant to seek help for mental health problems, little is understood as to why veterans encounter difficulties in engaging with treatment for alcohol misuse. The aim of this study was to understand why veterans in the United Kingdom are either reluctant or have difficulty in accessing help for alcohol problems. An applied social policy research methodology was used, employing in‐depth semi‐structured interviews with 19 UK veterans in the North East of England, who had a history of alcohol misuse. The findings showed that participants appeared to excuse or normalise their excessive alcohol consumption, which led to a delay in meaningful engagement in substance misuse services, resulting in complex and complicated presentations to health and social care services. The findings of this study clearly suggest that veterans who misuse alcohol have a range of distinctive and unique difficulties that subtly differentiate them from the wider civilian substance misuse population, and that the use of peer‐support models would appear to mitigate against them disengaging from alcohol treatment services.  相似文献   

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CONTEXT: Achieving competence in 'practice-based learning' implies that doctors can accurately self- assess their clinical skills to identify behaviours that need improvement. This study examines the impact of receiving feedback via performance benchmarks on medical students' self-assessment after a clinical performance examination (CPX). METHODS: The authors developed a practice-based learning exercise at 3 institutions following a required 8-station CPX for medical students at the end of Year 3. Standardised patients (SPs) scored students after each station using checklists developed by experts. Students assessed their own performance immediately after the CPX (Phase 1). One month later, students watched their videotaped performance and reassessed (Phase 2). Some students received performance benchmarks (their scores, plus normative class data) before the video review. Pearson's correlations between self-ratings and SP ratings were calculated for overall performance and specific skill areas (history taking, physical examination, doctor-patient communication) for Phase 1 and Phase 2. The 2 correlations were then compared for each student group (i.e. those who received and those who did not receive feedback). RESULTS: A total of 280 students completed both study phases. Mean CPX scores ranged from 51% to 71% of items correct overall and for each skill area. Phase 1 self-assessment correlated weakly with SP ratings of student performance (r = 0.01-0.16). Without feedback, Phase 2 correlations remained weak (r = 0.13-0.18; n = 109). With feedback, Phase 2 correlations improved significantly (r = 0.26-0.47; n = 171). Low-performing students showed the greatest improvement after receiving feedback. CONCLUSIONS: The accuracy of student self-assessment was poor after a CPX, but improved significantly with performance feedback (scores and benchmarks). Videotape review alone (without feedback) did not improve self-assessment accuracy. Practice-based learning exercises that incorporate feedback to medical students hold promise to improve self-assessment skills.  相似文献   

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BACKGROUND: The purpose of this project was to describe current nutrition support practice in the critical care setting and to identify interventions to target for quality improvement initiatives. METHODS: We conducted a cross-sectional national survey of dietitians working in intensive care units (ICUs) across Canada to document various aspects of nutrition support practice. RESULTS: Of the 79 dietitians sent study materials, 66 responded (83%). Sixteen of 66 sites (24.2%) reported the presence of a nutrition support team, and 35 of 66 (53%) used a standard enteral feeding protocol. Dietitians retrospectively abstracted data from charts of all patients in the ICU on April 18, 2001. Of 702 patients, 313 (44.6%) received enteral nutrition only, 50 (7.1%) received parenteral nutrition only, 60 (8.5%) received both, and 279 (39.7%) received no form of nutrition support. Enteral nutrition was initiated on 1.6 days (median) after admission to ICU; 10.7% of patients were initiated on day 1. Of those receiving any form of nutrition support, on average, patients received 58% of their prescribed amounts of calories and protein over the first 12 days in the ICU. Of all days on enteral feeds, patients received feeds into the small bowel on 381 of 2321 (16.4%) days. The mean head of the bed elevation for all patients was 30 degrees. Controlling for differences in patient characteristics, site factors contributing the most successful application of nutrition support included the amount of funded dietitians per ICU bed, size of ICU, and the fact that the ICU was located in an academic setting. CONCLUSIONS: A significant number of critically ill patients did not receive any form of nutrition support for the study period. Those that did receive nutrition support did not meet their prescribed energy or protein needs, especially earlier in the course of their illness. Significant opportunities to improve provision of nutrition support to critically ill patients exist.  相似文献   

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PURPOSE: This paper investigates the impact of quality-of-life adjustment on cost-effectiveness analyses, by comparing ratios from published studies that have reported both incremental costs per (unadjusted) life-year and per quality-adjusted life-year for the same intervention. METHODS: A systematic literature search identified 228 original cost-utility analyses published prior to 1998. Sixty-three of these analyses (173 ratio pairs) reported both cost/LY and cost/QALY ratios for the same intervention, from which we calculated medians and means, the difference between ratios (cost/LY minus cost/QALY) and between reciprocals of the ratios, and cost/LY as a percentage of the corresponding cost/QALY ratio. We also compared the ratios using rank-order correlation, and assessed the frequency with which quality-adjustment resulted in a ratio crossing the widely used cost-effectiveness thresholds of 20, 000 US dollars, 50,000 US dollars, and 100,000 US dollars/QALY or LY. RESULTS: The mean ratios were 69,100 US dollars/LY and 103,100 US dollars/QALY, with corresponding medians of 24,600 US dollars/LY and 20,400 US dollars/QALY. The mean difference between ratios was approximately -34,300 US dollars (median difference: 1300 US dollars), with 60% of ratio pairs differing by 10,000 US dollars/year or less. Mean difference between reciprocals was 59 (QA)LYs per million dollars (median: 2.1). The Spearman rank-order correlation between ratio types was 0.86 (p<0.001). Quality-adjustment led to a ratio moving either above or below 50,000 US dollars/LY (or QALY) in 8% of ratio pairs, and across 100,000 US dollars in 6% of cases. CONCLUSIONS: In a sizable fraction of cost-utility analyses, quality adjusting did not substantially alter the estimated cost-effectiveness of an intervention, suggesting that sensitivity analyses using ad hoc adjustments or 'off-the-shelf' utility weights may be sufficient for many analyses. The collection of preference weight data should be subjected to the same scrutiny as other data inputs to cost-effectiveness analyses, and should only be under-taken if the value of this information is likely to be greater than the cost of obtaining it.  相似文献   

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