10,136 research outputs found
Cost-effectiveness of physical fitness training for stroke survivors
Background Physical fitness is impaired after stroke, yet fitness training after stroke reduces disability. Several international guidelines recommend that fitness training be incorporated as part of stroke rehabilitation. However, information about cost-effectiveness is limited.
Methods A decision tree model was used to estimate the cost-effectiveness of a fitness programme for stroke survivors vs. relaxation (control group). This was based on a published randomised controlled trial, from which evidence about quality of life was used to estimate Quality Adjusted Life Years. Costs were based on the cost of the provision of group fitness classes within local community centres and a cost per Quality Adjusted Life Year was calculated.
Results The results of the base case analysis found an incremental cost per Quality Adjusted Life Year of £2,343.
Conclusions Physical fitness sessions after stroke are a cost-effective intervention for stroke survivors. This information will help make the case for the development of new services
Interventions for post-stroke fatigue
BACKGROUND: Post-stroke fatigue (PSF) is a common and distressing problem after stroke. The best ways to prevent or treat PSF are uncertain. Several different interventions can be argued to have a rational basis.
OBJECTIVES: To determine whether, among people with stroke, any intervention reduces the proportion of people with fatigue, fatigue severity, or both; and to determine the effect of intervention on health-related quality of life, disability, dependency and death, and whether such intervention is cost effective.
SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched May 2014), Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014, Issue 4), MEDLINE (1950 to May 2014), EMBASE (1980 to May 2014), CINAHL (1982 to May 2014), AMED (1985 to May 2014), PsycINFO (1967 to May 2014), Digital Dissertations (1861 to May 2014), British Nursing Index (1985 to May 2014), PEDro (searched May 2014) and PsycBITE (searched May 2014). We also searched four ongoing trials registries, scanned reference lists, performed citation tracking of included trials and contacted experts.
SELECTION CRITERIA: Two review authors independently scrutinised all titles and abstracts and excluded obviously irrelevant studies. We obtained the full texts for potentially relevant studies and three review authors independently applied the inclusion criteria. We included randomised controlled trials (RCTs) that compared an intervention with a control, or compared different interventions for PSF.
DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed risk of bias for each included trial. The primary outcomes were severity of fatigue, or proportion of people with fatigue after treatment. We performed separate analyses for trials investigating efficacy in treating PSF, trials investigating efficacy in preventing PSF and trials not primarily investigating efficacy in PSF but which reported fatigue as an outcome. We pooled results from trials that had a control arm. For trials that compared different potentially active interventions without a control arm, we performed analyses for individual trials without pooling.We calculated standardised mean difference (SMD) as the effect size for continuous outcomes and risk ratio (RR) for dichotomous outcomes. We pooled the results using a random-effects model and assessed heterogeneity using the I(2) statistic. We performed separate subgroup analyses for pharmacological and non-pharmacological interventions. We also performed sensitivity analyses to assess the influence of methodological quality.
MAIN RESULTS: We retrieved 12,490 citations, obtained full texts for 58 studies and included 12 trials (three from the 2008 search and nine from the 2014 search) with 703 participants. Eight trials primarily investigated the efficacy in treating PSF, of which six trials with seven comparisons provided data suitable for meta-analysis (five pharmacological interventions: fluoxetine, enerion, (-)-OSU6162, citicoline and a combination of Chinese herbs; and two non-pharmacological interventions: a fatigue education programme and a mindfulness-based stress reduction programme). The fatigue severity was lower in the intervention groups than in the control groups (244 participants, pooled SMD -1.07, 95% confidence interval (CI) -1.93 to -0.21), with significant heterogeneity between trials (I(2) = 87%, degrees of freedom (df) = 6, P value < 0.00001). The beneficial effect was not seen in trials that had used adequate allocation concealment (two trials, 89 participants, SMD -0.38, 95% CI -0.80 to 0.04) or trials that had used adequate blinding of outcome assessors (four trials, 198 participants, SMD -1.10, 95% CI -2.31 to 0.11).No trial primarily investigated the efficacy in preventing PSF.Four trials (248 participants) did not primarily investigate the efficacy on fatigue but other symptoms after stroke. None of these interventions showed any benefit on reducing PSF, which included tirilazad mesylate, continuous positive airway pressure for sleep apnoea, antidepressants and a self management programme for recovery from chronic diseases. AUTHORS'
CONCLUSIONS: There was insufficient evidence on the efficacy of any intervention to treat or prevent fatigue after stroke. Trials to date have been small and heterogeneous, and some have had a high risk of bias. Some of the interventions described were feasible in people with stroke, but their efficacy should be investigated in RCTs with a more robust study design and adequate sample sizes
The utility of surface magnetic field measurements in the MAGSAT program
To take full advantage of the global, vector, survey by the Magsat satellite, and international program of augmented surface measurements was proposed. For secular variation and upper mantle conductivity the proposed measurements are global. The repeat station measurements for secular variation should be occupied at 2-3 year intervals. A special observing period in November and December of 1979 is proposed during which simultaneous, continuous, global measurements for upper mantle conductivity studies are to be gathered. Finally, it is recommended that the networks in operation during the IMS extend their operation through the Fall of 1980 to provide correlative data useful for high latitude disturbance studies and for crustal conductivity studies
An improved viscid/inviscid interaction procedure for transonic flow over airfoils
A new interacting boundary layer approach for computing the viscous transonic flow over airfoils is described. The theory includes a complete treatment of viscous interaction effects induced by the wake and accounts for normal pressure gradient effects across the boundary layer near trailing edges. The method is based on systematic expansions of the full Reynolds equation of turbulent flow in the limit of Reynolds numbers, Reynolds infinity. Procedures are developed for incorporating the local trailing edge solution into the numerical solution of the coupled full potential and integral boundary layer equations. Although the theory is strictly applicable to airfoils with cusped or nearly cusped trailing edges and to turbulent boundary layers that remain fully attached to the airfoil surface, the method was successfully applied to more general airfoils and to flows with small separation zones. Comparisons of theoretical solutions with wind tunnel data indicate the present method can accurately predict the section characteristics of airfoils including the absolute levels of drag
Temperature, light and nitrate sensing coordinate Arabidopsis seed dormancy cycling resulting in winter and summer annual phenotypes
Seeds use environmental cues to sense the seasons and their surroundings to initiate the plants life cycle. Dormancy cycling underlying this process is extensively described, but the molecular mechanism is largely unknown. To address this we selected a range of representative genes from published array experiments in the laboratory and investigated their expression patterns in seeds of Arabidopsis ecotypes, having contrasting life cycles, over an annual dormancy cycle in the field. We show how mechanisms identified in the laboratory are coordinated in response to the soil environment to determine dormancy cycles that result in winter and summer annual phenotypes. Our results are consistent with a seed specific response to seasonal temperature patterns (temporal sensing) involving the gene DELAY OF GERMINATION1 (DOG1) that indicates the correct season; and concurrent temporally driven co-opted mechanisms that sense spatial signals i.e. nitrate via CBL-INTERACTING PROTEIN KINASE 23 (CIPK23) phosphorylation of the NITRATE TRANSPORTER 1 (NRT1.1) and light via PHYTOCHROME A (PHYA). In both ecotypes studied, when all three genes have low expression there is enhanced GIBBERELLIN 3 BETA-HYDROXYLASE 1 (GA3ox1) expression, exhumed seeds have the potential to germinate in the laboratory, and the initiation of seedling emergence occurs following soil disturbance (exposure to light) in the field. Unlike DOG1, expression of MOTHER of FLOWERING TIME (MFT) has an opposite thermal response in seeds of the two ecotypes indicating a role in determining their different dormancy cycling phenotypes
Interventions for improving upper limb function after stroke
Background:
Improving upper limb function is a core element of stroke rehabilitation needed to maximise patient outcomes and reduce disability. Evidence about effects of individual treatment techniques and modalities is synthesised within many reviews. For selection of effective rehabilitation treatment, the relative effectiveness of interventions must be known. However, a comprehensive overview of systematic reviews in this area is currently lacking.
Objectives:
To carry out a Cochrane overview by synthesising systematic reviews of interventions provided to improve upper limb function after stroke.
Methods:
Search methods: We comprehensively searched the Cochrane Database of Systematic Reviews; the Database of Reviews of Effects; and PROSPERO (an international prospective register of systematic reviews) (June 2013). We also contacted review authors in an effort to identify further relevant reviews.
Selection criteria: We included Cochrane and non‐Cochrane reviews of randomised controlled trials (RCTs) of patients with stroke comparing upper limb interventions with no treatment, usual care or alternative treatments. Our primary outcome of interest was upper limb function; secondary outcomes included motor impairment and performance of activities of daily living. When we identified overlapping reviews, we systematically identified the most up‐to‐date and comprehensive review and excluded reviews that overlapped with this.
Data collection and analysis: Two overview authors independently applied the selection criteria, excluding reviews that were superseded by more up‐to‐date reviews including the same (or similar) studies. Two overview authors independently assessed the methodological quality of reviews (using a modified version of the AMSTAR tool) and extracted data. Quality of evidence within each comparison in each review was determined using objective criteria (based on numbers of participants, risk of bias, heterogeneity and review quality) to apply GRADE (Grades of Recommendation, Assessment, Development and Evaluation) levels of evidence. We resolved disagreements through discussion. We systematically tabulated the effects of interventions and used quality of evidence to determine implications for clinical practice and to make recommendations for future research.
Main results:
Our searches identified 1840 records, from which we included 40 completed reviews (19 Cochrane; 21 non‐Cochrane), covering 18 individual interventions and dose and setting of interventions. The 40 reviews contain 503 studies (18,078 participants). We extracted pooled data from 31 reviews related to 127 comparisons. We judged the quality of evidence to be high for 1/127 comparisons (transcranial direct current stimulation (tDCS) demonstrating no benefit for outcomes of activities of daily living (ADLs)); moderate for 49/127 comparisons (covering seven individual interventions) and low or very low for 77/127 comparisons.
Moderate‐quality evidence showed a beneficial effect of constraint‐induced movement therapy (CIMT), mental practice, mirror therapy, interventions for sensory impairment, virtual reality and a relatively high dose of repetitive task practice, suggesting that these may be effective interventions; moderate‐quality evidence also indicated that unilateral arm training may be more effective than bilateral arm training. Information was insufficient to reveal the relative effectiveness of different interventions.
Moderate‐quality evidence from subgroup analyses comparing greater and lesser doses of mental practice, repetitive task training and virtual reality demonstrates a beneficial effect for the group given the greater dose, although not for the group given the smaller dose; however tests for subgroup differences do not suggest a statistically significant difference between these groups. Future research related to dose is essential.
Specific recommendations for future research are derived from current evidence. These recommendations include but are not limited to adequately powered, high‐quality RCTs to confirm the benefit of CIMT, mental practice, mirror therapy, virtual reality and a relatively high dose of repetitive task practice; high‐quality RCTs to explore the effects of repetitive transcranial magnetic stimulation (rTMS), tDCS, hands‐on therapy, music therapy, pharmacological interventions and interventions for sensory impairment; and up‐to‐date reviews related to biofeedback, Bobath therapy, electrical stimulation, reach‐to‐grasp exercise, repetitive task training, strength training and stretching and positioning.
Authors' conclusions:
Large numbers of overlapping reviews related to interventions to improve upper limb function following stroke have been identified, and this overview serves to signpost clinicians and policy makers toward relevant systematic reviews to support clinical decisions, providing one accessible, comprehensive document, which should support clinicians and policy makers in clinical decision making for stroke rehabilitation.
Currently, no high‐quality evidence can be found for any interventions that are currently used as part of routine practice, and evidence is insufficient to enable comparison of the relative effectiveness of interventions. Effective collaboration is urgently needed to support large, robust RCTs of interventions currently used routinely within clinical practice. Evidence related to dose of interventions is particularly needed, as this information has widespread clinical and research implications
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