Stroke literature synopses: clinical science

No abstract available

Diagnosis in vascular dementia, applying ‘Cochrane diagnosis rules’ to ‘dementia diagnostic tools’

In this issue of Clinical Science, Biesbroek and colleagues describe recent work on magnetic resonance imaging (MRI)-based cerebral lesion location and its association with cognitive decline. The authors conclude that diagnostic neuroimaging in dementia should shift from whole-brain evaluation to focused quantitative analysis of strategic brain areas. This commentary uses the review of lesion location mapping to discuss broader issues around studies of dementia test strategies. We draw upon work completed by the Cochrane Dementia and Cognitive Improvement Group designed to improve design, conduct and reporting of dementia biomarker studies

The LAST word on coaching as a stroke intervention?

No abstract available

Cognitive and mood assessment tools for use in stroke

No abstract available

Improving outcome assessment for clinical trials in stroke

Abstract Clinical trials are at the centre of advances in our understanding of stroke and its optimal treatment. In this thesis the uses and properties of outcome assessment scales for stroke trials are described, with particular attention given to the modified Rankin Scale (mRS). Through comprehensive literature review I will show that mRS is the most frequently used functional outcome scale in clinical trials but efficacy of the scale is potentially limited by inter-observer variability. Using a “mock” clinical trial design I demonstrate that inter-observer mRS variability in contemporary practice is moderate (k=0.57). Adding these data to systematic review of published data, confirms an overall moderate inter-observer variability across ten trials (k=0.46). Differing strategies to improve mRS reliability will then be described. I will outline development of a bespoke training package, international training scores across 2942 raters again confirms suboptimal reliability (k=0.67). A pilot trial using endpoint committee review of video recorded interviews demonstrates feasibility of this approach. Attempts to improve reliability by deriving mRS from data recorded in patients’ hospital records are not successful (k=0.34). In the final chapters I present a novel methodology for describing stroke outcomes – “home-time”. This measure shows good agreement with mRS, except at extremes of disability. Finally to put mRS in a historical context, the career of John Rankin and the development of his eponymous scale is recounted

Informant single screening questions for delirium and dementia in acute care – a cross-sectional test accuracy pilot study

Background Cognitive impairment often goes undetected in older people in hospital. Efficient screening tools are required to improve detection.<p></p> To determine diagnostic properties of two separate informant-based single screening questions for cognitive impairment (dementia and delirium) in hospitalised older people.<p></p> Methods Patients over 65 years non-electively admitted to medical or geriatric wards within a teaching hospital. Our index tests were single screening questions (SSQ), one for dementia (“How has your relative/friend’s memory changed over the past 5 years (up to just before their current illness)?”) and one for delirium (“How has your relative/friend’s memory changed with his/her current illness?”), which were assessed with informant response given on a five point Likert scale.<p></p> Any deterioration on our index tests of SSQ-dementia and SSQ-delirium was accepted as a positive screen for cognitive impairment. Scores were compared to the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) >3.38 accepted as dementia, and Confusion Assessment Method (CAM) diagnosis of delirium. We also collected direct cognitive screening data using Mini Mental Status Examination (MMSE).<p></p> Results Informant responses were obtained in 70/161 (43.5%) patients, median age 80.8 (range:67–97) years; mean MMSE score 18.5 (SD: 8.1). The SSQ-dementia when compared to the IQCODE had a sensitivity of 83.3% and specificity of 93.1%. The SSQ-delirium when compared to CAM diagnosis had sensitivity of 76.9% and a specificity of 56.1%.<p></p> Conclusions These findings show promise for use of an informant single screening question tool as the first step in detection of dementia in older people in acute hospital care, although this approach appears to be less accurate in screening for delirium.<p></p&gt

Functional assessment for acute stroke trials: properties, analysis, and application

A measure of treatment effect is needed to assess the utility of any novel intervention in acute stroke. For a potentially disabling condition such as stroke, outcomes of interest should include some measure of functional recovery. There are many functional outcome assessments that can be used after stroke. In this narrative review, we discuss exemplars of assessments that describe impairment, activity, participation, and quality of life. We will consider the psychometric properties of assessment scales in the context of stroke trials, focusing on validity, reliability, responsiveness, and feasibility. We will consider approaches to the analysis of functional outcome measures, including novel statistical approaches. Finally, we will discuss how advances in audiovisual and information technology could further improve outcome assessment in trials

Network meta-analysis of diagnostic test accuracy studies identifies and ranks the optimal diagnostic tests and thresholds for healthcare policy and decision making

Objective: Network meta-analyses have extensively been used to compare the effectiveness of multiple interventions for healthcare policy and decision-making. However, methods for evaluating the performance of multiple diagnostic tests are less established. In a decision-making context, we are often interested in comparing and ranking the performance of multiple diagnostic tests, at varying levels of test thresholds, in one simultaneous analysis. Study design and setting: Motivated by an example of cognitive impairment diagnosis following stroke, we synthesized data from 13 studies assessing the efficiency of two diagnostic tests: Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), at two test thresholds: MMSE <25/30 and <27/30, and MoCA <22/30 and <26/30. Using Markov Chain Monte Carlo (MCMC) methods, we fitted a bivariate network meta-analysis model incorporating constraints on increasing test threshold, and accounting for the correlations between multiple test accuracy measures from the same study. Results: We developed and successfully fitted a model comparing multiple tests/threshold combinations while imposing threshold constraints. Using this model, we found that MoCA at threshold <26/30 appeared to have the best true positive rate, whilst MMSE at threshold <25/30 appeared to have the best true negative rate. Conclusion: The combined analysis of multiple tests at multiple thresholds allowed for more rigorous comparisons between competing diagnostics tests for decision making

Thromboprophylaxis in atrial fibrillation and association with cognitive decline: systematic review

Objective:Atrial Fibrillation (AF) is associated with dementia. If AF-related cognitive decline is driven by cerebral embolic events, thromboprophylaxis may impact on this. This systematic review assessed the association between cognitive impairment and AF thromboprophylaxis. Methods:Two independent reviewers searched CINAHL, EMBASE, MEDLINE, PsycINFO, Web of Science Core Collection, and Cochrane Library from inception until 12th November 2014. Eligible studies compared AF thromboprophylaxis to control with an outcome measure of cognition or dementia. Where data allowed, meta-analyses describing between-group differences in cognitive test scores or rates of incident dementia were performed. Results:Nineteen studies were eligible. For two prospective studies (one RCT) comparing anticoagulation against antiplatelet therapy, change in Mini-Mental State Examination score from baseline to last follow-up (maximal duration:5.9 years) suggested a difference favouring anticoagulation (mean difference:0.90, 95% CI:0.29 to 1.51), in keeping with a trend seen in the single RCT (mean difference MMSE:0.80. 95% CI:-0.07 to 1.67). Pooled odds ratios suggested no association with incident dementia, comparing anticoagulant to antiplatelet therapy (two studies, OR:1.23, 95% CI:0.80 to 1.91) or no treatment (three studies, OR:0.89, 95%CI:0.47 to 1.69). Conclusions:Our analyses show no definitive evidence of cognitive benefit or harm from anticoagulation. We demonstrated a potential benefit of anticoagulation in comparison to antiplatelet over time. Larger-scale studies with longer follow-up are needed to determine the true cognitive impact of AF thromboprophylaxis