Lorne Becker

Survival After In-Hospital Cardiopulmonary Resuscitation: A Meta-Analysis

OBJECTIVE: To determine the rates of immediate survival and survival to discharge for adult patients undergoing in-hospital cardiopulmonary resuscitation, and to identify demographic and clinical variables associated with these outcomes.MEASUREMENTS AND MAIN RESULTS: The MEDLARS database of the National Library of Medicine was searched. In addition, the authors’ extensive personal files and the bibliography of each identified study were searched for further studies. Two sets of inclusion criteria were used, minimal (any study of adults undergoing in-hospital cardiopulmonary resuscitation) and strict (included only patients from general ward and intensive care units, and adequately defined cardiopulmonary arrest and resuscitation). Each study was independently reviewed and abstracted in a nonblinded fashion by two reviewers. The data abstracted were compared, and any discrepancies were resolved by consensus discussion. For the subset of studies meeting the strict criteria, the overall rate of immediate survival was 40.7% and the rate of survival to discharge was 13.4%. The following variables were associated with failure to survive to discharge: sepsis on the day prior to resuscitation (odds ratio [OR] 31.3; 95% confidence interval [CI] 1.9, 515), metastatic cancer (OR 3.9; 95% CI 1.2, 12.6), dementia (OR 3.1; 95% CI 1.1, 8.8), African-American race (OR 2.8; 95% CI 1.4, 5.6), serum creatinine level at a cutpoint of 1.5 mg/dL (OR 2.2; 95% CI 1.2, 3.8), cancer (OR 1.9; 95% CI 1.2, 3.0), coronary artery disease (OR 0.55; 95% CI 0.4, 0.8), and location of resuscitation in the intensive care unit (OR 0.51; 95% CI 0.4, 0.8).CONCLUSIONS: When talking with patients, physicians can describe the overall likelihood of surviving discharge as 1 in 8 for patients who undergo cardiopulmonary resuscitation and 1 in 3 for patients who survive cardiopulmonary resuscitation.

The evolution of a new publication type: Steps and challenges of producing overviews of reviews

BACKGROUND To date, the Cochrane Child Health Field has published 18 overviews of reviews in our journal, Evidence-based Child Health: A Cochrane Review Journal. In this article, we highlight some of the logistical and methodological challenges of producing such syntheses. As this is a new and evolving publication type, we hope that our experience will benefit others who engage in this process. Current Methods: We discuss the process we have developed to produce overviews of reviews relevant to our mandate, including identification of the research question, establishment of the author team, selection of outcomes and included SRs, and presentation of findings. Ongoing Development: We discuss the lessons we have learned, outstanding challenges for overview authors, and the limitations of overviews. CONCLUSIONS Overviews of reviews are only as good as the SRs and primary studies on which they are based; gaps or lack of currency in this evidence will weaken the overview of reviews. Future directions in this work must address questions of bias and loss of information. Methods for overviews of reviews targeted for specific groups, such as children, need more elaboration. Copyright

What guidance is available for researchers conducting overviews of reviews of healthcare interventions? A scoping review and qualitative metasummary

BackgroundOverviews of reviews (overviews) compile data from multiple systematic reviews to provide a single synthesis of relevant evidence for decision-making. Despite their increasing popularity, there is limited methodological guidance available for researchers wishing to conduct overviews. The objective of this scoping review is to identify and collate all published and unpublished documents containing guidance for conducting overviews examining the efficacy, effectiveness, and/or safety of healthcare interventions. Our aims were to provide a map of existing guidance documents; identify similarities, differences, and gaps in the guidance contained within these documents; and identify common challenges involved in conducting overviews.MethodsWe conducted an iterative and extensive search to ensure breadth and comprehensiveness of coverage. The search involved reference tracking, database and web searches (MEDLINE, EMBASE, DARE, Scopus, Cochrane Methods Studies Database, Google Scholar), handsearching of websites and conference proceedings, and contacting overview producers. Relevant guidance statements and challenges encountered were extracted, edited, grouped, abstracted, and presented using a qualitative metasummary approach.ResultsWe identified 52 guidance documents produced by 19 research groups. Relatively consistent guidance was available for the first stages of the overview process (deciding when and why to conduct an overview, specifying the scope, and searching for and including systematic reviews). In contrast, there was limited or conflicting guidance for the latter stages of the overview process (quality assessment of systematic reviews and their primary studies, collecting and analyzing data, and assessing quality of evidence), and many of the challenges identified were also related to these stages. An additional, overarching challenge identified was that overviews are limited by the methods, reporting, and coverage of their included systematic reviews.ConclusionsThis compilation of methodological guidance for conducting overviews of healthcare interventions will facilitate the production of future overviews and can help authors address key challenges they are likely to encounter. The results of this project have been used to identify areas where future methodological research is required to generate empirical evidence for overview methods. Additionally, these results have been used to update the chapter on overviews in the next edition of the Cochrane Handbook for Systematic Reviews of Interventions.

A Cochrane systematic review and network meta-analysis comparing treatment strategies aiming to decrease blood loss during liver resection.

INTRODUCTION Intraoperative haemorrhage remains one of the major risks during liver resection, and perioperative blood loss and blood transfusion are important factors affecting perioperative morbidity and mortality. The aim of this study is to compare treatment strategies aiming to decrease blood loss during hepatectomy. METHODS A systematic review of the literature was performed to identify randomised controlled trials reporting on the method of vascular occlusion, parenchymal transection, and management of the cut surface during liver resection. A Bayesian network meta-analysis was performed using WinBUGS. RESULTS Seven trials reporting on 496 participants randomised to seven treatment strategies were analysed. Continuous vascular occlusion resulted in lower blood loss compared to no vascular occlusion when parenchymal transection was performed with clamp-crush and no fibrin sealant was used for the cut surface. People undergoing liver resection by continuous vascular occlusion had decreased amounts of blood transfused than people with intermittent vascular occlusion when parenchymal transection was performed with clamp-crush and no fibrin sealant. There was no significant difference in proportion of people transfused, mortality, or hospital stay between the different strategies. There were significantly more serious adverse events when surgery was performed using radiofrequency dissecting sealer compared with standard clamp-crush method in the absence of vascular occlusion and fibrin sealant. CONCLUSIONS Continuous vascular occlusion during hepatectomy results in decreased blood loss and decreased blood transfusion requirements. Further studies are needed to compare treatment strategies aiming to decrease blood loss, defined by their method of vascular occlusion, parenchymal transection, and management of the cut surface.

A taxonomy has been developed for outcomes in medical research to help improve knowledge discovery.

Objectives There is increasing recognition that insufficient attention has been paid to the choice of outcomes measured in clinical trials. The lack of a standardized outcome classification system results in inconsistencies due to ambiguity and variation in how outcomes are described across different studies. Being able to classify by outcome would increase efficiency in searching sources such as clinical trial registries, patient registries, the Cochrane Database of Systematic Reviews, and the Core Outcome Measures in Effectiveness Trials (COMET) database of core outcome sets (COS), thus aiding knowledge discovery. Study Design and Setting A literature review was carried out to determine existing outcome classification systems, none of which were sufficiently comprehensive or granular for classification of all potential outcomes from clinical trials. A new taxonomy for outcome classification was developed, and as proof of principle, outcomes extracted from all published COS in the COMET database, selected Cochrane reviews, and clinical trial registry entries were classified using this new system. Results Application of this new taxonomy to COS in the COMET database revealed that 274/299 (92%) COS include at least one physiological outcome, whereas only 177 (59%) include at least one measure of impact (global quality of life or some measure of functioning) and only 105 (35%) made reference to adverse events. Conclusions This outcome taxonomy will be used to annotate outcomes included in COS within the COMET database and is currently being piloted for use in Cochrane Reviews within the Cochrane Linked Data Project. Wider implementation of this standard taxonomy in trial and systematic review databases and registries will further promote efficient searching, reporting, and classification of trial outcomes.

The efficient production of high quality evidence reviews is important for the public good

We support Tsafnat and colleagues’ argument that automation could transform systematic review production.1 Technological innovation has played a central role since the birth of systematic review,2 and machine processes are embedded throughout current systematic review workflow. Nevertheless, current methods are not sustainable in the face of the deluge of primary research. Few of the recent …

Medications for daytime sleepiness in individuals with idiopathic hypersomnia

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of medications for daytime sleepiness and related symptoms in individuals with idiopathic hypersomnia, and in particular whether medications may: 1. reduce subjective measures of sleepiness; 2. reduce objective measures of sleepiness; 3. reduce symptoms of cognitive dysfunction; 4. improve quality of life; and 5. be associated with adverse events.