scholarly journals Overview of Federated Facility to Harmonize, Analyze and Management of Missing Data in Cohorts

2019 ◽  
Vol 9 (19) ◽  
pp. 4103 ◽  
Author(s):  
Hema Sekhar Reddy Rajula ◽  
Veronika Odintsova ◽  
Mirko Manchia ◽  
Vassilios Fanos

Cohorts are instrumental for epidemiologically oriented observational studies. Cohort studies usually observe large groups of individuals for a specific period of time to identify the contributing factors to a specific outcome (for instance an illness) and create associations between risk factors and the outcome under study. In collaborative projects, federated data facilities are meta-database systems that are distributed across multiple locations that permit to analyze, combine, or harmonize data from different sources making them suitable for mega- and meta-analyses. The harmonization of data can increase the statistical power of studies through maximization of sample size, allowing for additional refined statistical analyses, which ultimately lead to answer research questions that could not be addressed while using a single study. Indeed, harmonized data can be analyzed through mega-analysis of raw data or fixed effects meta-analysis. Other types of data might be analyzed by e.g., random-effects meta-analyses or Bayesian evidence synthesis. In this article, we describe some methodological aspects related to the construction of a federated facility to optimize analyses of multiple datasets, the impact of missing data, and some methods for handling missing data in cohort studies.

2020 ◽  
Author(s):  
Nan Hu ◽  
Chunyi Wang ◽  
Yan Liao ◽  
Qichen Dai ◽  
Shiyi Cao

Abstract Background: Both smoking and insomnia are worldwide problems and this study aims to investigate the impact of smoking on the incidence of insomnia. Methods: PubMed, EMBASE and OVID were searched through March, 2020. Cohort studies reporting the effect of smoking on the incidence of insomnia were included. We quantitatively analyzed the basic framework and study characteristics, and then pooled estimate effects with 95% confidence intervals (CIs) of outcomes of each included studies using fixed-effects meta-analyses. Results: This systematic review included six cohort studies involving 12445 participants. Quantitatively summarized results suggested smoking could significantly increase the incidence of insomnia (OR: 1.07, 95%CI: 1.02,1.13). Regular smoking was significantly associated with incidence of insomnia (OR=1.07, 95% CI:1.01,1.13). As for occasional smokers and ex-smokers, the pooled analysis didn’t indicate a significant association (occasional smoker: OR=2.09, 95% CI:0.44,9.95; ex-smoker; OR=1.02, 95% CI:0.67,1.54). Subgroup analysis by age, gender ratio and region showed statistically significant relationship between smoking and incidence of insomnia in specific groups. Conclusions: Integrated longitudinal observational evidence identified smoking as a significant risk factor of insomnia. Considering the limited amount of available studies, more high-quality and prospective cohort studies of large sample sizes are needed to explore details of this association.


2020 ◽  
Author(s):  
Nan Hu ◽  
Chunyi Wang ◽  
Yan Liao ◽  
Qichen Dai ◽  
Shiyi Cao

Abstract Background: Both smoking and insomnia are worldwide problems and this study aims to investigate the impact of smoking on the incidence of insomnia. Methods: PubMed, EMBASE and OVID were searched through March, 2020. Cohort studies reporting the effect of smoking on the incidence of insomnia were included. We quantitatively analyzed the basic framework and study characteristics, and then pooled estimate effects with 95% confidence intervals (CIs) of outcomes of each included studies using fixed-effects meta-analyses. Results: This systematic review included six cohort studies involving 12445 participants. Quantitatively summarized results suggested smoking could significantly increase the incidence of insomnia (OR: 1.07, 95%CI: 1.02,1.13). Regular smoking was significantly associated with incidence of insomnia (OR=1.07, 95% CI:1.01,1.13). As for occasional smokers and ex-smokers, the pooled analysis didn’t indicate a significant association (occasional smoker: OR=2.09, 95% CI:0.44,9.95; ex-smoker; OR=1.02, 95% CI:0.67,1.54). Subgroup analysis by age, gender ratio and region showed statistically significant relationship between smoking and incidence of insomnia in specific groups. Conclusions: Integrated longitudinal observational evidence identified smoking as a significant risk factor of insomnia. Considering the limited amount of available studies, more high-quality and prospective cohort studies of large sample sizes are needed to explore details of this association.


2020 ◽  
Author(s):  
Nan Hu ◽  
Chunyi Wang ◽  
Yan Liao ◽  
Qichen Dai ◽  
Shiyi Cao

Abstract Background: Both smoking and insomnia are worldwide problems and this study aims to investigate the impact of smoking on the incidence of insomnia. Methods: PubMed, EMBASE and OVID were searched through March, 2020. Cohort studies reporting the effect of smoking on the incidence of insomnia were included. We quantitatively analyzed the basic framework and study characteristics, and then pooled estimate effects with 95% confidence intervals (CIs) of outcomes of each included studies using fixed-effects meta-analyses. Results: This systematic review included six cohort studies involving 12445 participants. Quantitatively summarized results suggested smoking could significantly increase the incidence of insomnia (OR: 1.07, 95%CI: 1.02,1.13). Regular smoking was significantly associated with incidence of insomnia (OR=1.07, 95% CI:1.01,1.13). As for occasional smokers and ex-smokers, the pooled analysis didn’t indicate a significant association (occasional smoker: OR=2.09, 95% CI:0.44,9.95; ex-smoker; OR=1.02, 95% CI:0.67,1.54). Subgroup analysis by age, gender ratio and region showed statistically significant relationship between smoking and incidence of insomnia in specific groups. Conclusions: Integrated longitudinal observational evidence identified smoking as a significant risk factor of insomnia. Considering the limited amount of available studies, more high-quality and prospective cohort studies of large sample sizes are needed to explore details of this association.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e14058-e14058
Author(s):  
Jane-Chloe Trone ◽  
Céline Chapelle ◽  
Edouard Ollier ◽  
Laurent Bertoletti ◽  
Michel Cucherat ◽  
...  

e14058 Background: Antiangiogenic (AA) therapies emerge as a new cornerstone for cancer treatment, but carry their own particular risk profile. Several previous meta-analyses have showed increasing risk of bleeding and paradoxically thrombosis in cancer patients receiving antiangiogenic. The aim of the meta-analysis is to investigate the impact of studies design (open or double blind (DB)), on the incidence and the occurrence of bleeding, venous thrombotic events (VTE) and arterial thrombotic events (ATE) in cancer patients treated by AA therapies. Methods: We searched Medline, Cochrane, ClinicalTrial databases, meeting abstracts of the American Society of Clinical Oncology and the European Society of Medical Oncology for relevant clinical trials. We included prospective phase II and III clinical trials that randomly assigned patients with solid cancer to AA therapy or control. Statistical analyses were conducted to calculate the summary incidence, ORs, and 95% CIs, using random-effects or fixed-effects models based on the heterogeneity of included studies. Results: A total of 166 trials (72,024 patients) were included. For bleeding events, comparison on AA treatment versus control yielded an OR of 2.41 (95% CI 2.07 to 2.71; p < 0.001) with an exaggeration of treatment effects by 68% (95% CI, 33 to 113) in open-label studies compared with DB trials. Concerning VTE, an OR of 1.18 (95% CI 1.04 to 1.35; p = 0.0115) was noted, with a significant enhancement of 53% (95% CI, 19 to 96) of treatment side effects with open trials compared with DB trials. AA don’t increase significantly the frequency of VTE when considering only DB trials. For ATE, an OR of 1.59 (95% CI 1.30 to 1.94; p < 0.001) was observed, associated with a significant exaggeration of 65% (95% CI, 13 to 143) with open trials compared with DB trials. Conclusions: The present meta-analysis showed a significant interaction of study design for the tolerance assessment in the AA therapies in cancers. The increasing risk of hemorrhagic events, VTE and ATE appear to have been overestimated in the previous meta-analyses. In the future, meta-analyses should be restricted to DB trials for analysis of toxicity profile.


2011 ◽  
Vol 101 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Henry K. Ngugi ◽  
Paul D. Esker ◽  
Harald Scherm

The continuing exponential increase in scientific knowledge, the growing availability of large databases containing raw or partially annotated information, and the increased need to document impacts of large-scale research and funding programs provide a great incentive for integrating and adding value to previously published (or unpublished) research through quantitative synthesis. Meta-analysis has become the standard for quantitative evidence synthesis in many disciplines, offering a broadly accepted and statistically powerful framework for estimating the magnitude, consistency, and homogeneity of the effect of interest across studies. Here, we review previous and current uses of meta-analysis in plant pathology with a focus on applications in epidemiology and disease management. About a dozen formal meta-analyses have been published in the plant pathological literature in the past decade, and several more are currently in progress. Three broad research questions have been addressed, the most common being the comparative efficacy of chemical treatments for managing disease and reducing yield loss across environments. The second most common application has been the quantification of relationships between disease intensity and yield, or between different measures of disease, across studies. Lastly, meta-analysis has been applied to assess factors affecting pathogen–biocontrol agent interactions or the effectiveness of biological control of plant disease or weeds. In recent years, fixed-effects meta-analysis has been largely replaced by random- (or mixed-) effects analysis owing to the statistical benefits associated with the latter and the wider availability of computer software to conduct these analyses. Another recent trend has been the more common use of multivariate meta-analysis or meta-regression to analyze the impacts of study-level independent variables (moderator variables) on the response of interest. The application of meta-analysis to practical problems in epidemiology and disease management is illustrated with case studies from our work on Phakopsora pachyrhizi on soybean and Erwinia amylovora on apple. We show that although meta-analyses are often used to corroborate and validate general conclusions drawn from more traditional, qualitative reviews, they can also reveal new patterns and interpretations not obvious from individual studies.


Neonatology ◽  
2020 ◽  
Vol 117 (3) ◽  
pp. 259-270 ◽  
Author(s):  
Sophie Jansen ◽  
Enrico Lopriore ◽  
Christiana Naaktgeboren ◽  
Marieke Sueters ◽  
Jacqueline Limpens ◽  
...  

<b><i>Background:</i></b> While epidural analgesia (EA) is associated with maternal fever during labor, the impact on the risk for maternal and/or neonatal sepsis is unknown. <b><i>Objectives:</i></b> The aim of this systematic review was to investigate the effect of epidural-related intrapartum fever on maternal and neonatal outcomes. <b><i>Methods:</i></b> OVID MEDLINE, OVID Embase, the Cochrane Library, Cochrane Controlled Register of Trials, and clinical trial registries were searched for randomized controlled trials (RCT) and observational cohort studies from inception to November 2018. A total of 761 studies were identified with 100 eligible for full-text review. Only articles investigating the relationship between EA and maternal fever during labor were eligible for inclusion. Study quality was assessed using the Cochrane’s Risk of Bias tool and National Institute of Health Quality Assessment Tool. Two meta-analyses – one each for the RCT and observational cohort groups – were performed using the random-effects model of Mantel-Haenszel to produce summary risk ratios (RR) with 95% CI. <b><i>Results:</i></b> Twelve RCTs and 16 observational cohort studies involving 579,157 parturients were included. RRs for maternal fever for the RCT and cohort analyses were 3.54 (95% CI 2.61–4.81) and 5.60 (95% CI 4.50–6.97), respectively. Meta-analyses of RR for maternal infection in both groups were infeasible given few occurrences. Meta-analysis of data from observational studies showed an increased risk for maternal antibiotic treatment in the epidural group (RR 2.60; 95% CI 1.31–5.17). For both analyses, neonates born to women with an epidural were not evaluated more often for suspected sepsis. Neither analysis reported an increased rate of neonatal bacteremia or neonatal antibiotic treatment after EA, although data precluded conclusiveness. <b><i>Conclusion:</i></b> EA increases the risk of intrapartum fever and maternal antibiotic treatment. However, a definite conclusion on whether EA increases the risk for a proven maternal and/or neonatal bacteremia cannot be drawn due to the low quality of data. Further research on whether epidural-related intrapartum fever is of infectious origin or not is therefore needed.


2020 ◽  
Author(s):  
Nan Hu ◽  
Chunyi Wang ◽  
Yan Liao ◽  
Qichen Dai ◽  
Shiyi Cao

Abstract Background Both smoking and sleep disorder are worldwide problems and this study aim to investigate the impact of smoking on the incidence of sleep disorder. Methods PubMed, EMBASE and OVID were searched through March, 2020. Cohort studies reporting the effect of smoking on the incidence of sleep disorder were included. We quantitatively analyzed the basic framework and study characteristics, and then pooled estimate effects with 95% confidence intervals (CIs) of outcomes of each included studies using fixed-effects meta-analyses. Results This systematic review included seven cohort studies involving 17,414 participants. Quantitatively summarized results suggested smoking could increase the incidence of sleep disorder (OR: 1.08, 95%CI: 1.02,1.13). For regular smokers and occasional smokers, significant association between smoking and incidence of sleep disorder was found (regular smoker: OR = 1.07, 95% CI:1.01,1.13; occasional smoker: OR = 1.62, 95% CI:1.15,2.28). As for ex-smokers, the pooled analysis didn’t indicate a positive association (OR = 1.02, 95% CI:0.67,1.54). Subgroup analysis by age, gender ratio and religion showed statistically significant relationship between smoking and incidence of sleep disorder in specific groups. Conclusions Integrated longitudinal observational evidence identified smoking as a significant risk factor of sleep disorder. Considering the limited amount of available researches, more high-quality and prospective cohort studies of large sample sizes are needed to explore details of this association.


2020 ◽  
Vol 228 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Michael Kossmeier ◽  
Ulrich S. Tran ◽  
Martin Voracek

Abstract. Currently, dedicated graphical displays to depict study-level statistical power in the context of meta-analysis are unavailable. Here, we introduce the sunset (power-enhanced) funnel plot to visualize this relevant information for assessing the credibility, or evidential value, of a set of studies. The sunset funnel plot highlights the statistical power of primary studies to detect an underlying true effect of interest in the well-known funnel display with color-coded power regions and a second power axis. This graphical display allows meta-analysts to incorporate power considerations into classic funnel plot assessments of small-study effects. Nominally significant, but low-powered, studies might be seen as less credible and as more likely being affected by selective reporting. We exemplify the application of the sunset funnel plot with two published meta-analyses from medicine and psychology. Software to create this variation of the funnel plot is provided via a tailored R function. In conclusion, the sunset (power-enhanced) funnel plot is a novel and useful graphical display to critically examine and to present study-level power in the context of meta-analysis.


2021 ◽  
Vol 11 (6) ◽  
pp. 755
Author(s):  
Falonn Contreras-Osorio ◽  
Christian Campos-Jara ◽  
Cristian Martínez-Salazar ◽  
Luis Chirosa-Ríos ◽  
Darío Martínez-García

One of the most studied aspects of children’s cognitive development is that of the development of the executive function, and research has shown that physical activity has been demonstrated as a key factor in its enhancement. This meta-analysis aims to assess the impact of specific sports interventions on the executive function of children and teenagers. A systematic review was carried out on 1 November 2020 to search for published scientific evidence that analysed different sports programs that possibly affected executive function in students. Longitudinal studies, which assessed the effects of sports interventions on subjects between 6 and 18 years old, were identified through a systematic search of the four principal electronic databases: Web of Science, PubMed, Scopus, and EBSCO. A total of eight studies, with 424 subjects overall, met the inclusion criteria and were classified based on one or more of the following categories: working memory, inhibitory control, and cognitive flexibility. The random-effects model for meta-analyses was performed with RevMan version 5.3 to facilitate the analysis of the studies. Large effect sizes were found in all categories: working memory (ES −1.25; 95% CI −1.70; −0.79; p < 0.0001); inhibitory control (ES −1.30; 95% CI −1.98; −0.63; p < 0.00001); and cognitive flexibility (ES −1.52; 95% CI −2.20; −0.83; p < 0.00001). Our analysis concluded that healthy children and teenagers should be encouraged to practice sports in order to improve their executive function at every stage of their development.


2021 ◽  
Vol 5 (1) ◽  
pp. e100135
Author(s):  
Xue Ying Zhang ◽  
Jan Vollert ◽  
Emily S Sena ◽  
Andrew SC Rice ◽  
Nadia Soliman

ObjectiveThigmotaxis is an innate predator avoidance behaviour of rodents and is enhanced when animals are under stress. It is characterised by the preference of a rodent to seek shelter, rather than expose itself to the aversive open area. The behaviour has been proposed to be a measurable construct that can address the impact of pain on rodent behaviour. This systematic review will assess whether thigmotaxis can be influenced by experimental persistent pain and attenuated by pharmacological interventions in rodents.Search strategyWe will conduct search on three electronic databases to identify studies in which thigmotaxis was used as an outcome measure contextualised to a rodent model associated with persistent pain. All studies published until the date of the search will be considered.Screening and annotationTwo independent reviewers will screen studies based on the order of (1) titles and abstracts, and (2) full texts.Data management and reportingFor meta-analysis, we will extract thigmotactic behavioural data and calculate effect sizes. Effect sizes will be combined using a random-effects model. We will assess heterogeneity and identify sources of heterogeneity. A risk-of-bias assessment will be conducted to evaluate study quality. Publication bias will be assessed using funnel plots, Egger’s regression and trim-and-fill analysis. We will also extract stimulus-evoked limb withdrawal data to assess its correlation with thigmotaxis in the same animals. The evidence obtained will provide a comprehensive understanding of the strengths and limitations of using thigmotactic outcome measure in animal pain research so that future experimental designs can be optimised. We will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines and disseminate the review findings through publication and conference presentation.


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