102 research outputs found
The relationship between physical activity and lymphoma: a systematic review and meta analysis
BACKGROUND: The literature suggests an increased risk between anthropometrics including higher body mass index and lymphoma incidence; however, the association with physical activity remains unclear. A systematic review/meta-analysis was therefore performed to examine this association with physical activity (total, recreational or occupational).
METHODS: PubMed, Web of Science and Embase were reviewed from inception to October 2019 identifying relevant observational studies. Non-Hodgkin lymphoma (NHL) including subtypes diffuse large B cell lymphoma, follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, and Hodgkin lymphoma (HL) were analyzed. Included studies reported activity, lymphoma cases, effect size and variability measures, and were restricted to human subjects of any age. Data was pooled generating summary relative risk (RR) estimates with 95% confidence intervals (CI) using random-effects models with primary outcome of histologically confirmed incident lymphoma.
RESULTS: One thousand four hundred studies were initially identified with 18 studies (nine cohort, nine case-control) included in final analysis. Comparing highest vs. lowest activity categories was protective for all lymphoma (RR 0.89, 95%CI 0.81-0.98). Sensitivity analysis demonstrated effect persistence within case-control studies (RR 0.82, 95% CI 0.71-0.96), but not cohort studies (RR 0.95, 95%CI 0.84-1.07). Borderline protective effect was seen for NHL (RR 0.92, 95%CI 0.84-1.00), but not HL (RR 0.72, 95%CI 0.50-1.04). Analysis by NHL subtype or gender showed no effect. Dose response analysis demonstrated a protective effect (p = 0.034) with a 1% risk reduction per 3 MET hours/week (RR 0.99, 95%CI 0.98-1.00).
CONCLUSIONS: Physical activity may have a protective effect against lymphoma development; further studies are required to generate recommendations regarding health policy.
TRIAL REGISTRATION: This study was registered prospectively at PROSPERO: CRD42020156242
Intravenous corticosteroid treatment in adult patients with sepsis defined by the Sepsis-3 criteria: a systematic review and meta-analysis
Objectives To summarize the effects of intravenous corticosteroid treatment for sepsis defined by the Sepsis-3 criteria in adult patients.
Design Systematic review and meta-analysis.
Methods We searched RCTs from PubMed, Embase, ClinicalTrials.gov, Cochrane Central Register of Controlled Trials, Web of Science, and International Clinical Trials Registry Platform from inception to July 12th, 2019 and updated on June 28th, 2020. Conference proceedings from relevant societies and the reference lists of previous reviews were manually screened. Abstract or full-text articles were screened by two independent investigators. We included RCTs where (1) the participants had infections and the baseline Sequential Organ Failure Assessment (SOFA) score ≥ 2 (the Sepsis-3 definitions) (2) the intervention involved any intravenous corticosteroids; (3) the control group received placebo or standard of care (4) the outcomes of interest included mortality or clinical recovery. We chose the 28-day mortality as the pre-specified primary outcome and risk ratio (RR) as the effect measure. We followed PRISMA guidelines and chose random-effects models for the pooled analyses.
Results This study included 24 RCTs and 19 of them (7,115 participants) reported the 28-day mortality. Pooled analyses showed that intravenous corticosteroid treatment compared to placebo or standard of care was not associated with a lower risk of 28-day mortality (RR, 0.88; 95%CI, 0.73 to 1.05), but with a higher risk of hyperglycemia (RR, 1.16; 95%CI, 1.06 to 1.27). Sensitivity analysis of high-quality studies revealed a similar result for the 28-day mortality (RR, 0.95; 95%CI, 0.86 to 1.05).
Conclusions Our findings suggested that intravenous corticosteroids compared to placebo or standard of care may not reduce the 28-day mortality in adult patients with sepsis defined by the Sepsis-3 criteria. Further studies are warranted to clarify the roles of disease severity and treatment timing in the effects of corticosteroid treatment in this population.
PROSPERO registration number CRD4201914308
A 7-Step Guideline for Qualitative Synthesis and Meta-Analysis of Observational Studies in Health Sciences
Objectives: To provide a step-by-step, easy-to-understand, practical guide for systematic review and meta-analysis of observational studies. Methods: A multidisciplinary team of researchers with extensive experience in observational studies and systematic review and meta-analysis was established. Previous guidelines in evidence synthesis were considered. Results: There is inherent variability in observational study design, population, and analysis, making evidence synthesis challenging. We provided a framework and discussed basic meta-analysis concepts to assist reviewers in making informed decisions. We also explained several statistical tools for dealing with heterogeneity, probing for bias, and interpreting findings. Finally, we briefly discussed issues and caveats for translating results into clinical and public health recommendations. Our guideline complements "A 24-step guide on how to design, conduct, and successfully publish a systematic review and meta-analysis in medical research" and addresses peculiarities for observational studies previously unexplored. Conclusion: We provided 7 steps to synthesize evidence from observational studies. We encourage medical and public health practitioners who answer important questions to systematically integrate evidence from observational studies and contribute evidence-based decision-making in health sciences
Protocol for the development of a reporting guideline for umbrella reviews on epidemiological associations using cross-sectional, case-control and cohort studies: the Preferred Reporting Items for Umbrella Reviews of Cross-sectional, Case-control and Cohort studies (PRIUR-CCC).
INTRODUCTION
Observational studies are fraught with several biases including reverse causation and residual confounding. Overview of reviews of observational studies (ie, umbrella reviews) synthesise systematic reviews with or without meta-analyses of cross-sectional, case-control and cohort studies, and may also aid in the grading of the credibility of reported associations. The number of published umbrella reviews has been increasing. Recently, a reporting guideline for overviews of reviews of healthcare interventions (Preferred Reporting Items for Overviews of Reviews (PRIOR)) was published, but the field lacks reporting guidelines for umbrella reviews of observational studies. Our aim is to develop a reporting guideline for umbrella reviews on cross-sectional, case-control and cohort studies assessing epidemiological associations.
METHODS AND ANALYSIS
We will adhere to established guidance and prepare a PRIOR extension for systematic reviews of cross-sectional, case-control and cohort studies testing epidemiological associations between an exposure and an outcome, namely Preferred Reporting Items for Umbrella Reviews of Cross-sectional, Case-control and Cohort studies (PRIUR-CCC). Step 1 will be the project launch to identify stakeholders. Step 2 will be a literature review of available guidance to conduct umbrella reviews. Step 3 will be an online Delphi study sampling 100 participants among authors and editors of umbrella reviews. Step 4 will encompass the finalisation of PRIUR-CCC statement, including a checklist, a flow diagram, explanation and elaboration document. Deliverables will be (i) identifying stakeholders to involve according to relevant expertise and end-user groups, with an equity, diversity and inclusion lens; (ii) completing a narrative review of methodological guidance on how to conduct umbrella reviews, a narrative review of methodology and reporting in published umbrella reviews and preparing an initial PRIUR-CCC checklist for Delphi study round 1; (iii) preparing a PRIUR-CCC checklist with guidance after Delphi study; (iv) publishing and disseminating PRIUR-CCC statement.
ETHICS AND DISSEMINATION
PRIUR-CCC has been approved by The Ottawa Health Science Network Research Ethics Board and has obtained consent (20220639-01H). Participants to step 3 will give informed consent. PRIUR-CCC steps will be published in a peer-reviewed journal and will guide reporting of umbrella reviews on epidemiological associations
The MEDEA childhood asthma study design for mitigation of desert dust health effects: implementation of novel methods for assessment of air pollution exposure and lessons learned
Background: Desert dust events in Mediterranean countries, originating mostly from the Sahara and Arabian deserts, have been linked to climate change and are associated with significant increase in mortality and hospital admissions from respiratory causes. The MEDEA clinical intervention study in children with asthma is funded by EU LIFE+ program to evaluate the efficacy of recommendations aiming to reduce exposure to desert dust and related health effects. Methods: This paper describes the design, methods, and challenges of the MEDEA childhood asthma study, which is performed in two highly exposed regions of the Eastern Mediterranean: Cyprus and Greece-Crete. Eligible children are recruited using screening surveys performed at primary schools and are randomized to three parallel intervention groups: a) no intervention for desert dust events, b) interventions for outdoor exposure reduction, and c) interventions for both outdoor and indoor exposure reduction. At baseline visits, participants are enrolled on MEDena® Health-Hub, which communicates, alerts and provides exposure reduction recommendations in anticipation of desert dust events. MEDEA employs novel environmental epidemiology and telemedicine methods including wearable GPS, actigraphy, health parameters sensors as well as indoor and outdoor air pollution samplers to assess study participants’ compliance to recommendations, air pollutant exposures in homes and schools, and disease related clinical outcomes. Discussion: The MEDEA study evaluates, for the first time, interventions aiming to reduce desert dust exposure and implement novel telemedicine methods in assessing clinical outcomes and personal compliance to recommendations. In Cyprus and Crete, during the first study period (February–May 2019), a total of 91 children participated in the trial while for the second study period (February–May 2020), another 120 children completed data collection. Recruitment for the third study period (February–May 2021) is underway. In this paper, we also present the unique challenges faced during the implementation of novel methodologies to reduce air pollution exposure in children. Engagement of families of asthmatic children, schools and local communities, is critical. Successful study completion will provide the knowledge for informed decision-making both at national and international level for mitigating the health effects of desert dust events in South-Eastern Europe. Trial registration: ClinicalTrials.gov: NCT03503812, April 20, 2018
Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality: Results From 27 Countries.
BACKGROUND
Cardiovascular disease is the leading cause of death worldwide. Existing studies on the association between temperatures and cardiovascular deaths have been limited in geographic zones and have generally considered associations with total cardiovascular deaths rather than cause-specific cardiovascular deaths.
METHODS
We used unified data collection protocols within the Multi-Country Multi-City Collaborative Network to assemble a database of daily counts of specific cardiovascular causes of death from 567 cities in 27 countries across 5 continents in overlapping periods ranging from 1979 to 2019. City-specific daily ambient temperatures were obtained from weather stations and climate reanalysis models. To investigate cardiovascular mortality associations with extreme hot and cold temperatures, we fit case-crossover models in each city and then used a mixed-effects meta-analytic framework to pool individual city estimates. Extreme temperature percentiles were compared with the minimum mortality temperature in each location. Excess deaths were calculated for a range of extreme temperature days.
RESULTS
The analyses included deaths from any cardiovascular cause (32 154 935), ischemic heart disease (11 745 880), stroke (9 351 312), heart failure (3 673 723), and arrhythmia (670 859). At extreme temperature percentiles, heat (99th percentile) and cold (1st percentile) were associated with higher risk of dying from any cardiovascular cause, ischemic heart disease, stroke, and heart failure as compared to the minimum mortality temperature, which is the temperature associated with least mortality. Across a range of extreme temperatures, hot days (above 97.5th percentile) and cold days (below 2.5th percentile) accounted for 2.2 (95% empirical CI [eCI], 2.1-2.3) and 9.1 (95% eCI, 8.9-9.2) excess deaths for every 1000 cardiovascular deaths, respectively. Heart failure was associated with the highest excess deaths proportion from extreme hot and cold days with 2.6 (95% eCI, 2.4-2.8) and 12.8 (95% eCI, 12.2-13.1) for every 1000 heart failure deaths, respectively.
CONCLUSIONS
Across a large, multinational sample, exposure to extreme hot and cold temperatures was associated with a greater risk of mortality from multiple common cardiovascular conditions. The intersections between extreme temperatures and cardiovascular health need to be thoroughly characterized in the present day-and especially under a changing climate
Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality: Results From 27 Countries
Background: Cardiovascular disease is the leading cause of death worldwide. Existing studies on the association between temperatures and cardiovascular deaths have been limited in geographic zones and have generally considered associations with total cardiovascular deaths rather than cause-specific cardiovascular deaths.
Methods: We used unified data collection protocols within the Multi-Country Multi-City Collaborative Network to assemble a database of daily counts of specific cardiovascular causes of death from 567 cities in 27 countries across 5 continents in overlapping periods ranging from 1979 to 2019. City-specific daily ambient temperatures were obtained from weather stations and climate reanalysis models. To investigate cardiovascular mortality associations with extreme hot and cold temperatures, we fit case-crossover models in each city and then used a mixed-effects meta-analytic framework to pool individual city estimates. Extreme temperature percentiles were compared with the minimum mortality temperature in each location. Excess deaths were calculated for a range of extreme temperature days.
Results: The analyses included deaths from any cardiovascular cause (32 154 935), ischemic heart disease (11 745 880), stroke (9 351 312), heart failure (3 673 723), and arrhythmia (670 859). At extreme temperature percentiles, heat (99th percentile) and cold (1st percentile) were associated with higher risk of dying from any cardiovascular cause, ischemic heart disease, stroke, and heart failure as compared to the minimum mortality temperature, which is the temperature associated with least mortality. Across a range of extreme temperatures, hot days (above 97.5th percentile) and cold days (below 2.5th percentile) accounted for 2.2 (95% empirical CI [eCI], 2.1–2.3) and 9.1 (95% eCI, 8.9–9.2) excess deaths for every 1000 cardiovascular deaths, respectively. Heart failure was associated with the highest excess deaths proportion from extreme hot and cold days with 2.6 (95% eCI, 2.4–2.8) and 12.8 (95% eCI, 12.2–13.1) for every 1000 heart failure deaths, respectively.
Conclusions: Across a large, multinational sample, exposure to extreme hot and cold temperatures was associated with a greater risk of mortality from multiple common cardiovascular conditions. The intersections between extreme temperatures and cardiovascular health need to be thoroughly characterized in the present day—and especially under a changing climate.Clinical Perspective_ What Is New?: This study provided evidence from what we believe is the largest multinational dataset ever assembled on cardiovascular outcomes and environmental exposures; Extreme hot and cold temperatures were associated with increased risk of death from any cardiovascular cause, ischemic heart disease, stroke, and heart failure; For every 1000 cardiovascular deaths, 2 and 9 excess deaths were attributed to extreme hot and cold days, respectively.
_ What Are the Clinical Implications?: Extreme temperatures from a warming planet may become emerging priorities for public health and preventative cardiology; The findings of this study should prompt professional cardiology societies to commission scientific statements on the intersections of extreme temperature exposure and cardiovascular health.This study was supported by the Kuwait Foundation for the Advancement of Science (CB21-63BO-01); the US Environmental Protection Agency (RD-835872); Harvard Chan National Institute of Environmental Health Sciences Center for Environmental Health (P01ES009825); the UK Medical Research Council (MR/R013349/1); the UK Natural Environment Research Council (NE/R009384/1); the European Union’s Horizon 2020 Project Exhaustion (820655); the Australian National Health and Medical Research Council (APP 2000581, APP 1109193, APP 1163693); the National Institute of Environmental Health Sciences–funded HERCULES Center (P30ES019776); the MCIN/AEI/10.13039/501100011033 (grant CEX2018-000794-S); the Taiwanese Ministry of Science and Technology (MOST 109–2621-M-002–021); the Environmental Restoration and Conservation Agency, Environment Research and Technology Development Fund (JPMEERF15S11412); the São Paulo Research Foundation; and Fundação para a Ciência e a Tecnlogia (SFRH/BPD/115112/2016)info:eu-repo/semantics/publishedVersio
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
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