Key design elements of successful acute ischemic stroke treatment trials.

PURPOSE: We review key design elements of positive randomized controlled trials (RCTs) in acute ischemic stroke (AIS) treatment and summarize their main characteristics. METHOD: We searched Medline, Pubmed and Cochrane databases for positive RCTs in AIS treatment. Trials were included if (1) they had a randomized controlled design, with (at least partial) blinding for endpoints, (2) they tested against placebo (or on top of standard therapy in a superiority design) or against approved therapy; (3) the protocol was registered and/or published before trial termination and unblinding (if required at study commencement); (4) the primary endpoint was positive in the intention to treat analysis; and (5) the study findings led to approval of the investigational product and/or high ranked recommendations. A topical approach was used, therefore the findings were summarized as a narrative review. FINDINGS: Seventeen positive RCTs met the inclusion criteria. The majority of trials included less than 1000 patients (n = 15), had highly selective inclusion criteria (n = 16), used the modified Rankin score as a primary endpoint (n = 15) and had a frequentist design (n = 16). Trials tended to be national (n = 12), investigator-initiated and performed with public funding (n = 11). DISCUSSION: Smaller but selective trials are useful to identify efficacy in a particular subgroup of stroke patients. It may also be of advantage to limit the number of participating countries and centers to avoid heterogeneity in stroke management and bureaucratic burden. CONCLUSION: The key characteristics of positive RCTs in AIS treatment described here may assist in the design of further trials investigating a single intervention with a potentially high effect size.

Pre-hospital prediction of adverse outcomes in patients with suspected COVID-19: Development, application and comparison of machine learning and deep learning methods.

BACKGROUND: COVID-19 infected millions of people and increased mortality worldwide. Patients with suspected COVID-19 utilised emergency medical services (EMS) and attended emergency departments, resulting in increased pressures and waiting times. Rapid and accurate decision-making is required to identify patients at high-risk of clinical deterioration following COVID-19 infection, whilst also avoiding unnecessary hospital admissions. Our study aimed to develop artificial intelligence models to predict adverse outcomes in suspected COVID-19 patients attended by EMS clinicians. METHOD: Linked ambulance service data were obtained for 7,549 adult patients with suspected COVID-19 infection attended by EMS clinicians in the Yorkshire and Humber region (England) from 18-03-2020 to 29-06-2020. We used support vector machines (SVM), extreme gradient boosting, artificial neural network (ANN) models, ensemble learning methods and logistic regression to predict the primary outcome (death or need for organ support within 30 days). Models were compared with two baselines: the decision made by EMS clinicians to convey patients to hospital, and the PRIEST clinical severity score. RESULTS: Of the 7,549 patients attended by EMS clinicians, 1,330 (17.6%) experienced the primary outcome. Machine Learning methods showed slight improvements in sensitivity over baseline results. Further improvements were obtained using stacking ensemble methods, the best geometric mean (GM) results were obtained using SVM and ANN as base learners when maximising sensitivity and specificity. CONCLUSIONS: These methods could potentially reduce the numbers of patients conveyed to hospital without a concomitant increase in adverse outcomes. Further work is required to test the models externally and develop an automated system for use in clinical settings.

The Landscape of Videofluoroscopy in the UK: A Web-Based Survey.

Videofluoroscopy (VFS) is considered one of the gold-standard assessments of swallowing. Whilst guidelines for the application and conduct of VFS exist, their translation into clinical practice remain challenging. To build a greater understanding on how VFS clinics operate in the UK. A web-based survey was shared with speech and language therapists (SLTs) working in VFS clinics via professional networks and social media from October 2018 to January 2019. 101 responses were received. Two thirds of clinics were SLT-led, with the majority of clinics being run by two SLTs (73.6%) and a radiographer (95.5%) also known as radiologic technologists, diagnostic radiographers and medical radiation technologists. Less than 50% of radiographers had received specialist training. Around half of the clinics used a standard assessment or analysis protocol and 88.1% a rating scale. Set recipes for a range of textures were used in 53.4% of VFS clinics. Barium and water soluble contrasts were used, but only 15.8% knew the concentration of contrast used. The most commonly reported VFS pulse and frame rate was 15 per second. There was evidence of a lack of SLT knowledge regarding technical operation of VFS. Screening times varied from 0.7-10 min (median 3 min, IQR 2.5-3.5). Around 50% of respondents reported quality issues affecting analysis. In a survey of UK SLTs, translation of VFS guidance into practice was found to be limited which may impact on the quality of assessment and analysis. Collaboration with radiology, strengthening of guidelines and greater uptake of specialist training is deemed essential.

Evaluation of websites that contain information relating to malaria in pregnancy.

OBJECTIVES: The study identified available websites on malaria in pregnancy on the World Wide Web and sought to evaluate their readability and information quality. STUDY DESIGN: A purposeful sample of websites were selected which provided information on Malaria in pregnancy. METHODS: A total of 31 websites were identified from searches using Google, Yahoo and Bing search engines. Two generic tools (Discern and HON), one specific tool designed to assess information quality of malaria in pregnancy and readability tests (Flesch Reading Ease and Flesh-Kincaid Grade level) were used to evaluate the websites. RESULTS: Most of the websites scored below 50% with the HON Code tool, with most lacking information on the symptoms. One website scored over 70 with the reading ease with two (2) achieving a score of 7 for the reading level test. The readability of the websites was too advanced for an ordinary consumer. CONCLUSION: The results of this study indicated that the information quality of malaria in pregnancy websites varied from fair to medium. It was also found that the readability of the websites was too advanced for an ordinary consumer. These findings suggest that most websites are not comprehensive in addressing all the relevant aspects of malaria in pregnancy.

Impact of heart rate on admission on mortality and morbidity in acute ischaemic stroke patients - results from VISTA.

BACKGROUND AND PURPOSE: Elevated heart rate (HR) is associated with worse outcomes in patients with cardiovascular disease. Its predictive value in acute stroke patients is less well established. We investigated the effects of HR on admission in acute ischaemic stroke patients. METHODS: Using the Virtual International Stroke Trials Archive (VISTA) database, the association between HR in acute stroke patients without atrial fibrillation and the pre-defined composite end-point of (recurrent) ischaemic stroke, transient ischaemic attack (TIA), myocardial infarction (MI) and vascular death within 90 days was analysed. Pre-defined secondary outcomes were the composite end-point components and any death, decompensated heart failure and degree of functional dependence according to the modified Rankin Scale after 90 days. HR was analysed as a categorical variable (quartiles). RESULTS: In all, 5606 patients were available for analysis (mean National Institutes of Health Stroke Scale 13; mean age 67 years; mean HR 77 bpm; 44% female) amongst whom the composite end-point occurred in 620 patients (11.1%). Higher HR was not associated with the composite end-point. The frequencies of secondary outcomes were 3.2% recurrent stroke (n = 179), 0.6% TIA (n = 35), 1.8% MI (n = 100), 6.8% vascular death (n = 384), 15.0% any death (n = 841) and 2.2% decompensated heart failure (n = 124). Patients in the highest quartile (HR> 86 bpm) were at increased risk for any death [adjusted hazard ratio (95% confidence interval) 1.40 (1.11-1.75)], decompensated heart failure [adjusted hazard ratio 2.20 (1.11-4.37)] and worse modified Rankin Scale [adjusted odds ratio 1.29 (1.14-1.52)]. CONCLUSIONS: In acute stroke patients, higher HR (>86 bpm) is linked to mortality, heart failure and higher degree of dependence after 90 days but not to recurrent stroke, TIA or MI.

Post-stroke cognitive decline: an update and perspectives for clinical research.

The close relationship between stroke and dementia is an important health issue. Ischaemic stroke can facilitate the onset of vascular dementia as well as aggravate pre-existing cognitive decline. The onset of cognitive decline may become manifest immediately following the onset of ischaemic stroke, but often there is a delay in the development of cognitive decline after a stroke. This delay can be seen as a therapeutic time window allowing interventions to be applied to preserve cognition following stroke. Both neurodegenerative and vascular mechanisms are activated and probably result in overlapping processes within the neurovascular unit. This review focuses on the incidence and prevalence of cognitive decline following stroke, predisposing stroke aetiologies, pre-stroke decline, imaging factors and biomarkers. Outcomes are discussed in relation to timing of assessment and neuropsychological tests used for evaluation of cognitive decline in ischaemic stroke patients. Including such tests in routine evaluations of stroke patients after some weeks or months is recommended. Finally, an outlook on ongoing and planned intervention trials is added and some recommendations for future research are proposed.

Can comprehensive specialised end-of-life care be provided at home? Lessons from a study of an innovative consultant-led community service in the UK.

The Midhurst Macmillan Specialist Palliative Care Service (MMSPCS) is a UK, medical consultant-led, multidisciplinary team aiming to provide round-the-clock advice and care, including specialist interventions, in the home, community hospitals and care homes. Of 389 referrals in 2010/11, about 85% were for cancer, from a population of about 155 000. Using a mixed method approach, the evaluation comprised: a retrospective analysis of secondary-care use in the last year of life; financial evaluation of the MMSPCS using an Activity Based Costing approach; qualitative interviews with patients, carers, health and social care staff and MMSPCS staff and volunteers; a postal survey of General Practices; and a postal survey of bereaved caregivers using the MMSPCS. The mean cost is about 3000 GBP (3461 EUR) per patient with mean cost of interventions for cancer patients in the last year of life 1900 GBP (2192 EUR). Post-referral, overall costs to the system are similar for MMSPCS and hospice-led models; however, earlier referral avoided around 20% of total costs in the last year of life. Patients and carers reported positive experiences of support, linked to the flexible way the service worked. Seventy-one per cent of patients died at home. This model may have application elsewhere.

Dipyridamole-induced headache and lower recurrence risk in secondary prevention of ischaemic stroke: a post hoc analysis.

BACKGROUND AND PURPOSE: Our objective was to investigate the association between recurrent stroke risk and headache induced by extended-release dipyridamole (ER-DP) when administered alone or with low-dose aspirin (ASA+ER-DP). METHODS: This was a post hoc analysis of prospectively collected data on recurrent stroke risk and headache as an adverse event or reason for treatment discontinuation from the PRoFESS (N = 20,332) and ESPS2 (N = 6602) trials. Hazard ratios (HRs) for recurrent stroke were calculated using the Cox model. RESULTS: In PRoFESS, the 2.5-year recurrent stroke risk in patients receiving ASA+ER-DP was 8.2% in those with headache within 7 days of starting treatment and 9.4% in those without [HR 0.85, 95% confidence interval (CI) 0.73-0.98; P = 0.03]. Recurrent stroke risk was 5.0% in patients who discontinued ASA+ER-DP due to headache by day 90 versus 9.2% in those who did not (HR 0.52, 95% CI 0.35-0.77; P = 0.001). No such difference was observed in clopidogrel-treated patients. In ESPS2, risk of recurrent stroke was 6.2% in patients who discontinued ASA+ER-DP due to headache by day 90 versus 9.8% in patients who did not (HR 0.62, 95% CI 0.31-1.27; P = 0.19) and 7.3% in patients who discontinued ER-DP due to headache by day 90 versus 13.2% in those who did not (HR 0.53, 95% CI 0.27-1.04; P = 0.06). CONCLUSIONS: Patients taking ASA+ER-DP in PRoFESS who developed headache had significantly reduced stroke recurrence risk versus those without headache. Similar (non-significant) findings for ASA+ER-DP and ER-DP in ESPS2 suggest that dipyridamole-induced headache may reflect better cerebrovascular function.

Progesterone and cerebral ischaemia: the relevance of ageing.

Cerebral stroke is a leading cause of long-term disability and a major cause of death in the developed world. The total incidence of stroke is projected to rise substantially over the next 20 years as a result of the rising elderly population. Although age is one of the most significant prognostic markers for poor outcome after stroke, very few experimental studies have been conducted in aged animals. Importantly, sex differences in both vulnerability to stroke and outcome after cerebral ischaemia have frequently been reported and attributed to the action of steroid hormones. Progesterone is a candidate neuroprotective factor for stroke, although the majority of pre-clinical studies have focused on using young, healthy adult animals. In terms of cerebral stroke, males and postmenopausal females represent the groups at highest risk of cerebral stroke and these categories can be modelled using either aged or ovariectomised female animals. In this review, we discuss the importance of conducting experimental studies in aged animals compared to young, healthy animals, as well as the impact this has on experimental outcomes. In addition, we focus on reviewing the studies that have been conducted to date examining the neuroprotective potential of progesterone in aged animals. Importantly, the limited studies that have been conducted in aged animals do lend further support to progesterone as a therapeutic option after ischaemic stroke that warrants further investigation.

A study on the use of Gumbel approximation with the Bernoulli spatial scan statistic.

The Bernoulli version of the spatial scan statistic is a well established method of detecting localised spatial clusters in binary labelled point data, a typical application being the epidemiological case-control study. A recent study suggests the inferential accuracy of several versions of the spatial scan statistic (principally the Poisson version) can be improved, at little computational cost, by using the Gumbel distribution, a method now available in SaTScan(TM) (www.satscan.org). We study in detail the effect of this technique when applied to the Bernoulli version and demonstrate that it is highly effective, albeit with some increase in false alarm rates at certain significance thresholds. We explain how this increase is due to the discrete nature of the Bernoulli spatial scan statistic and demonstrate that it can affect even small p-values. Despite this, we argue that the Gumbel method is actually preferable for very small p-values. Furthermore, we extend previous research by running benchmark trials on 12 000 synthetic datasets, thus demonstrating that the overall detection capability of the Bernoulli version (i.e. ratio of power to false alarm rate) is not noticeably affected by the use of the Gumbel method. We also provide an example application of the Gumbel method using data on hospital admissions for chronic obstructive pulmonary disease.

Does the cognitive measure Cog-4 show improvement among patients treated with thrombolysis after acute stroke?

BACKGROUND: Although the established measure of disability post stroke, the modified Rankin Scale emphasizes motor function and may underestimate the importance of cognitive impairment in more disabled patients. A subset of four items from the National Institutes of Health Stroke Scale has been proposed to assess cognitive function after stroke (Cog-4), and to correlate with modified Rankin Scale. Items correspond to orientation, executive function, language, and inattention. We investigated responsiveness of Cog-4 to treatment with thrombolysis and whether it offers information that supplements modified Rankin Scale. METHODS: We included 6268 patients from the Virtual International Stroke Trials Archive: 2734 received intravenous thrombolysis and 3534 were treated conservatively. We compared day 90 outcomes between treated and untreated groups, by modified Rankin Scale (illustrative) and by Cog-4 (primary measure) adjusting for age, baseline National Institutes of Health stroke scale, hemispheric lateralisation as well as baseline Cog-4 and baseline National Institutes of Health Stroke Scale excluding baseline Cog-4 separately. Analysis of Cog-4 was repeated within strata of 90 day modified Rankin Scale. Statistical analyses included proportional odds logistic regression and Cochran-Mantel-Haenszel test. RESULTS: Modified Rankin Scale showed a difference between treatment groups of expected magnitude (odds ratio 1·56; 95% confidence interval 1·43-1·72; P < 0·001). After adjustment for imbalance in baseline prognostic factors, the distribution of Cog-4 scores at 90 days was better in thrombolysed patients compared with nonthrombolysed patients (odds ratio 1·31; 95% confidence interval 1·18-1·47; P = 0·006). However, Cog-4 analysis stratified by 90-day modified Rankin Scale was neutral between treatment groups (OR 1·01; 95% CI 0·90-1·14), and Cog-4 was not responsive to treatment group even within modified Rankin Scale categories 4 and 5 despite substantial cognitive deficits in these patients. CONCLUSION: Although Cog-4 may be responsive to treatment effects, it does not provide additional information beyond modified Rankin Scale assessment.

Clinical and neuropsychological aspects of non-fatal self-harm in schizophrenia.

PURPOSE: To investigate demographic, clinical and neuropsychological aspects of self-harm in schizophrenia and identify which are independently predictive of and therefore the most relevant to clinical intervention. SUBJECTS AND METHODS: Eighty-seven patients with schizophrenia were interviewed regarding substance misuse, depression, hopelessness, negative/positive symptoms and illness insight. Neuropsychological assessment included premorbid IQ, continuous performance test, cognitive-motor and trait impulsivity. A prospective three-month review of medical records was also undertaken. RESULTS: Fifty-nine patients (68%) reported past self-harm (including attempted suicide). Those with past self-harm, compared to those without, were significantly more likely to report depression, hopelessness, impulsivity, a family history of self-harm, polysubstance abuse and had higher premorbid IQ. Logistic regression revealed that depression, higher premorbid IQ and polysubstance abuse were independently linked to self-harm. Five participants attempted self-harm during the 3-month prospective follow-up period. These all had a history of past self-harm and were significantly more likely to have been depressed at the initial interview than those who did not go on to self-harm. DISCUSSION AND CONCLUSIONS: Independent predictors of self-harm in schizophrenia are premorbid IQ and polysubstance abuse. In addition, depression was both independently associated with past self-harm and predictive of self-harm in the follow-up period.

Analytic Hierarchy Process (AHP) for examining healthcare professionals' assessments of risk factors. The relative importance of risk factors for falls in community-dwelling older people.

BACKGROUND: A gap exists between evidence-based medicine and clinical-practice. Every day, healthcare professionals (HCPs) combine empirical evidence and subjective experience in order to maximize the effectiveness of interventions. Consequently, it is important to understand how HCPs interpret the research evidence and apply it in everyday practice. We focused on the prevention of falls, a common cause of injury-related morbidity and mortality in later life, for which there is a wide range of known risk factors. OBJECTIVES: To use the Analytic Hierarchy Process (AHP) to investigate the opinions of HCPs in prioritizing risk factors for preventing falls. METHODS: We used the AHP to develop a hierarchy of risk factors for falls based on the knowledge and experience of experts. We submitted electronic questionnaires via the web, in order to reach a wider number of respondents. With a web service, we pooled the results and weighted the coherence and the experience of respondents. RESULTS: Overall, 232 respondents participated in the study: 32 in the technical pilot study, nine in the scientific pilot study and 191 respondents in the main study. We identified a hierarchy of 35 risk factors, organized in two categories and six sub-categories. CONCLUSIONS: The hierarchy of risk factors provides further insights into clinicians' perceptions of risk factors for falls. This hierarchy helps understand the relative importance that clinicians place on risk factors for falls in older people and why evidence-based guidelines are not always followed. This information may be helpful in improving intervention programs and in understanding how clinicians prioritize multiple risk factors in individual patients. The AHP method allows the opinions of HCPs to be investigated, giving appropriate weight to their coherence, background and experience.

Assessing quality of care from hospital case notes: comparison of reliability of two methods.

OBJECTIVES: To determine which of the two methods of case note review provide the most useful and reliable information for reviewing quality of care. DESIGN: Retrospective, multiple reviews of 692 case notes were undertaken using both holistic (implicit) and criterion-based (explicit) review methods. Quality measures were evidence-based review criteria and a quality of care rating scale. SETTING: Nine randomly selected acute hospitals in England. PARTICIPANTS: Sixteen doctors, 11 specialist nurses and three clinically trained audit staff, and eight non-clinical audit staff. ANALYSIS METHODS: Intrarater consistency, inter-rater reliability between pairs of staff using intraclass correlation coefficients (ICCs), completeness of criterion data capture and between-staff group comparison. RESULTS: A total of 1473 holistic reviews and 1389 criterion-based reviews were undertaken. When the three same staff types reviewed the same record, holistic scale score inter-rater reliability was moderate within each group (ICC 0.46 to 0.52). Inter-rater reliability for criterion-based scores was moderate to good (ICC 0.61 to 0.88). Comparison of holistic review score and criterion-based score of case notes reviewed by doctors and by non-clinical audit staff showed a reasonable level of agreement between the two methods. CONCLUSIONS: Using a holistic approach to review case notes, same staff groups can achieve reasonable repeatability within their professional groups. When the same clinical record was reviewed twice by the doctors, and by the non-clinical audit staff, using both holistic and criterion-based methods, there are close similarities between the quality of care scores generated by the two methods. When using retrospective review of case notes to examine quality of care, a clear view is required of the purpose and the expected outputs of the project.

Comparison of case note review methods for evaluating quality and safety in health care.

OBJECTIVES: To determine which of two methods of case note review--holistic (implicit) and criterion-based (explicit)--provides the most useful and reliable information for quality and safety of care, and the level of agreement within and between groups of health-care professionals when they use the two methods to review the same record. To explore the process-outcome relationship between holistic and criterion-based quality-of-care measures and hospital-level outcome indicators. DATA SOURCES: Case notes of patients at randomly selected hospitals in England. REVIEW METHODS: In the first part of the study, retrospective multiple reviews of 684 case notes were undertaken at nine acute hospitals using both holistic and criterion-based review methods. Quality-of-care measures included evidence-based review criteria and a quality-of-care rating scale. Textual commentary on the quality of care was provided as a component of holistic review. Review teams comprised combinations of: doctors (n = 16), specialist nurses (n = 10) and clinically trained audit staff (n = 3) and non-clinical audit staff (n = 9). In the second part of the study, process (quality and safety) of care data were collected from the case notes of 1565 people with either chronic obstructive pulmonary disease (COPD) or heart failure in 20 hospitals. Doctors collected criterion-based data from case notes and used implicit review methods to derive textual comments on the quality of care provided and score the care overall. Data were analysed for intrarater consistency, inter-rater reliability between pairs of staff using intraclass correlation coefficients (ICCs) and completeness of criterion data capture, and comparisons were made within and between staff groups and between review methods. To explore the process-outcome relationship, a range of publicly available health-care indicator data were used as proxy outcomes in a multilevel analysis. RESULTS: Overall, 1473 holistic and 1389 criterion-based reviews were undertaken in the first part of the study. When same staff-type reviewer pairs/groups reviewed the same record, holistic scale score inter-rater reliability was moderate within each of the three staff groups [intraclass correlation coefficient (ICC) 0.46-0.52], and inter-rater reliability for criterion-based scores was moderate to good (ICC 0.61-0.88). When different staff-type pairs/groups reviewed the same record, agreement between the reviewer pairs/groups was weak to moderate for overall care (ICC 0.24-0.43). Comparison of holistic review score and criterion-based score of case notes reviewed by doctors and by non-clinical audit staff showed a reasonable level of agreement (p-values for difference 0.406 and 0.223, respectively), although results from all three staff types showed no overall level of agreement (p-value for difference 0.057). Detailed qualitative analysis of the textual data indicated that the three staff types tended to provide different forms of commentary on quality of care, although there was some overlap between some groups. In the process-outcome study there generally were high criterion-based scores for all hospitals, whereas there was more interhospital variation between the holistic review overall scale scores. Textual commentary on the quality of care verified the holistic scale scores. Differences among hospitals with regard to the relationship between mortality and quality of care were not statistically significant. CONCLUSIONS: Using the holistic approach, the three groups of staff appeared to interpret the recorded care differently when they each reviewed the same record. When the same clinical record was reviewed by doctors and non-clinical audit staff, there was no significant difference between the assessments of quality of care generated by the two groups. All three staff groups performed reasonably well when using criterion-based review, although the quality and type of information provided by doctors was of greater value. Therefore, when measuring quality of care from case notes, consideration needs to be given to the method of review, the type of staff undertaking the review, and the methods of analysis available to the review team. Review can be enhanced using a combination of both criterion-based and structured holistic methods with textual commentary, and variation in quality of care can best be identified from a combination of holistic scale scores and textual data review.

Accessibility versus confidentiality of information in the emergency department.

INTRODUCTION: In the emergency department (ED), clinicians can benefit greatly from having access to information at the point of care. It has been suggested that using computerised information systems could improve the accessibility of information. However, making information accessible, while maintaining confidentiality, is one of the main challenges of implementing information systems. This article presents the ED staff perspectives about the accessibility and confidentiality of information in the ED. METHOD: The authors undertook a qualitative study in March-April 2007. Data were collected using in-depth semi-structured interviews with the ED staff of an ED located in Northern England. In total, 34 interviews were conducted and transcribed verbatim. Data were analysed using framework analysis. RESULTS: The results showed that the ED staff had role-based access to the current information systems, and these systems met only a small part of their information needs. As a result, different sources were used to get access to the needed information. Although the ED staff believed that improving the accessibility of information could be helpful in emergency care services, there were concerns about the confidentiality of information. The confidentiality of information could be threatened--for example, by sharing passwords, misusing patient information or by unauthorised staff having access to patient information. CONCLUSION: To design a system, the accessibility and confidentiality of information should be addressed in parallel. A balance between these two is needed, as the failure of each of these may negatively influence the use of the system.

Emulating multicentre clinical stroke trials: a new paradigm for studying novel interventions in experimental models of stroke.

The recent meta-analysis of NXY-059 in experimental stroke models using individual animal data found the drug to be an effective neuroprotective agent. However, the failure of translation of both this compound and many others from preclinical studies to the clinic indicates that new approaches must be used in drug discovery so that animal models become more reflective of the clinical situation, and studies using animal models of stroke mimic the design of studies performed in humans, as far as possible. In this review, we suggest that a fundamental paradigm shift is needed away from performing preclinical studies in individual laboratories to performing them in an organised group of independent laboratories. Studies should be run by a steering committee and should be supported by a coordinating centre, external data monitoring committee and outcome adjudication committee. This structure will mimic the practice of multicentre clinical trials. By doing so, future studies will minimise potential sources of bias including randomisation, concealment of allocation, blinding of surgery and outcome assessment and ensure publication of all data. It is likely that individual studies will involve increased heterogeneity and therefore will need to be larger. However, regular independent monitoring of data will allow development of interventions to be ceased immediately if neutral or negative data are obtained. The additional costs involved should be seen as reasonable when compared with the resources that would have been expended in running a clinical trial that subsequently proved negative.

Effects of NXY-059 in experimental stroke: an individual animal meta-analysis.

BACKGROUND AND PURPOSE: Disodium 2,4-disulphophenyl-N-tert-butylnitrone (NXY-059) was neuroprotective in experimental stroke models but ineffective in a large clinical trial. This first-ever individual animal meta-analysis was used to assess the preclinical studies. EXPERIMENTAL APPROACH: Studies were obtained from AstraZeneca and PubMed searches. Data for each animal were obtained from the lead author of each study and/or AstraZeneca. Published summary data were used if individual data were not available. Infarct volume and motor impairment were standardized to reflect different species and scales. Standardized mean difference (SMD), coefficients from multilevel models and 95% confidence intervals (95% CI) are presented. KEY RESULTS: Fifteen studies (26 conditions, 12 laboratories) involving rats (544), mice (9) and marmosets (32) were identified (NXY-059: 332, control: 253) with individual data for 442 animals. Four studies were unpublished. Studies variably used randomization (40%), blinding of surgeon (53%) and outcome assessor (67%). NXY-059 reduced total (SMD -1.17, 95% CI -1.50 to -0.84), cortical (SMD -2.17, 95% CI -2.99 to -1.34) and subcortical (-1.43, 95% CI -2.20 to -0.86) lesion volume; efficacy was seen in transient, permanent and thrombotic ischaemia, up to 180 min post occlusion. NXY-059 reduced motor impairment (SMD -1.66, 95% CI -2.18 to -1.14) and neglect. Evidence for performance, attrition and publication bias was present. CONCLUSIONS AND IMPLICATIONS: NXY-059 was neuroprotective in experimental stroke although bias may have resulted in efficacy being overestimated. Efficacy in young, healthy, male animals is a poor predictor of clinical outcome. We suggest the use of preclinical meta-analysis before initiation of future clinical trials.

The development of a clinically useful tool for predicting the development of psychological disorder following injury.

OBJECTIVES: To identify factors significantly associated with post-traumatic stress disorder (PTSD), anxiety, and depression at 3 months post-injury; to develop a generic model to predict the occurrence of PTSD, anxiety, and depression at 3 months post-injury; and to validate this model in a test data set of patients. DESIGN: Prospective cohort study. METHODS: Participants were 823 patients attending an emergency department (ED) following accidental injury. Baseline questionnaires were completed, with 1 and 3 months postal follow-ups. Predictor variables demonstrating significant associations with two of the three outcome measures (3-month HAD anxiety and depression scores and PTSD symptoms) were included in multivariate regression models for each outcome. Non-significant predictor variables were removed until all remaining independent variables made the most significant contribution to each of the three models. Models were validated using a test dataset. RESULTS: Previous history of mental health problems, neuroticism score and having PTSD symptoms at 1 month predicted adverse outcomes at 3 months. When used on the test datasets, the areas under the receiver operating curve (ROC) curve for the models predicting outcomes at 3 months were: PTSD=0.91 (sensitivity=88.5%); anxiety=0.87 (sensitivity=93.7%); and depression=0.87 (sensitivity=96.7%). CONCLUSIONS: The final model performed moderately well across the three outcomes and may be useful clinically as a generic rule-out tool to identify those who will not require follow up, watchful waiting or intervention.

Dipyridamole plus aspirin versus aspirin alone in secondary prevention after TIA or stroke: a meta-analysis by risk.

OBJECTIVES: To study the effect of combination therapy with aspirin and dipyridamole (A+D) over aspirin alone (ASA) in secondary prevention after transient ischaemic attack (TIA) or minor stroke of presumed arterial origin and to perform subgroup analyses to identify patients that might benefit most from secondary prevention with A+D. DATA SOURCES: The previously published meta-analysis of individual patient data was updated with data from ESPRIT (n = 2,739); trials without data on the comparison of A+D versus ASA were excluded. REVIEW METHODS: A meta-analysis was performed using Cox regression, including several subgroup analyses and following baseline risk stratification. RESULTS: A total of 7612 patients (five trials) were included in the analyses, 3800 allocated to A+D and 3812 to ASA alone. The trial-adjusted hazard ratio (HR) for the composite event of vascular death, non-fatal myocardial infarction and non-fatal stroke was 0.82 (95% confidence interval (CI) 0.72 to 0.92). HRs did not differ in subgroup analyses based on age, sex, qualifying event, hypertension, diabetes, previous stroke, ischaemic heart disease, aspirin dose, type of vessel disease and dipyridamole formulation, nor across baseline risk strata as assessed with two different risk scores. A+D were also more effective than ASA alone in preventing recurrent stroke; HR 0.78 (95% CI 0.68 to 0.90). CONCLUSION: The combination of aspirin and dipyridamole is more effective than aspirin alone in patients with TIA or ischaemic stroke of presumed arterial origin in the secondary prevention of stroke and other vascular events. This superiority was found in all subgroups and was independent of baseline risk.