scholarly journals Contribution of Informed Reference Prior Using Primary and Summary Measure Data in Bayesian Meta-Analysis

2015 ◽  
Vol 63 (2) ◽  
pp. 61-65
Author(s):  
Most Sifat Muntaha Soni ◽  
Md Belal Hossain
Keyword(s):  
Primary Outcome ◽  
Meta Analysis ◽  
Measure Data ◽  
Binary Outcomes ◽  
Reference Prior ◽  
Summary Measure ◽  
Prior Distributions ◽  
Study Heterogeneity ◽  
The Common

When meta-analysis includes a small number of trials, inferences are sensitive to the choice of prior distributions for between-study heterogeneity. The common practice is to use vague prior but inferences depend on the degree of vagueness. Pullenayegum (2011) proposed an informed reference prior for between-study heterogeneity of binary outcomes. We employ a model for applying this prior for both primary outcome and summary measure data in Bayesian meta-analysis. We have found the same inference using both primary outcome and summary measure data. This study also suggests that the informed reference prior for between-study heterogeneity represents more relevant conclusion as compared to commonly used prior distributions.Dhaka Univ. J. Sci. 63(2): 61-65, 2015 (July)

scholarly journals The choice and definition of summary measure for meta-analysis of clinical studies with binary outcomes: effect on clinical interpretation

2020 ◽  
Vol 93 (1108) ◽  
pp. 20190976
Author(s):  
Andrew A Plumb ◽  
Steve Halligan ◽  
Susan Mallett
Keyword(s):  
Relative Risk ◽  
Cancer Screening ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Binary Outcomes ◽  
Healthcare Intervention ◽  
Binary Outcome ◽  
Summary Measure ◽  
Definition Of ◽  
Meta Analyses

Many systematic reviews and meta-analyses concern the effect of a healthcare intervention on a binary outcome i.e. occurrence (or not) of a particular event. Usually, the overall effect, pooled across all studies included in the meta-analysis, is summarised using the odds ratio (OR) or the relative risk (RR). Under most circumstances, it is obvious how to identify what should be considered as the event of interest—for example, death or a clinically important side-effect. However, on occasion it may not be clear in which “direction” the event should be specified—such as attendance (vs non-attendance) at cancer screening. Usually, this choice is not critical to the overall conclusion of the meta-analysis, but occasionally it can lead to differences in how the included studies are pooled, ultimately affecting the overall meta-analytic result, particularly when using RRs rather than ORs. In this commentary, we will explain this phenomenon in more detail using examples from the literature, and explore how analysts and readers can avoid some potential pitfalls.

scholarly journals The common risk factors for progression and mortality in COVID-19 patients: a meta-analysis

2021 ◽  
Author(s):  
Li Zhang ◽  
Jie Hou ◽  
Fu-Zhe Ma ◽  
Jia Li ◽  
Shuai Xue ◽  
...  
Keyword(s):  
Risk Factors ◽  
Meta Analysis ◽  
Common Risk Factors ◽  
The Common

scholarly journals Genetic factors influencing a neurobiological substrate for psychiatric disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Till F. M. Andlauer ◽  
Thomas W. Mühleisen ◽  
Felix Hoffstaedter ◽  
Alexander Teumer ◽  
Katharina Wittfeld ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Genetic Risk ◽  
Meta Analysis ◽  
Anterior Cingulate ◽  
Psychiatric Disease ◽  
Salience Network ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Common Substrate ◽  
The Common

AbstractA retrospective meta-analysis of magnetic resonance imaging voxel-based morphometry studies proposed that reduced gray matter volumes in the dorsal anterior cingulate and the left and right anterior insular cortex—areas that constitute hub nodes of the salience network—represent a common substrate for major psychiatric disorders. Here, we investigated the hypothesis that the common substrate serves as an intermediate phenotype to detect genetic risk variants relevant for psychiatric disease. To this end, after a data reduction step, we conducted genome-wide association studies of a combined common substrate measure in four population-based cohorts (n = 2271), followed by meta-analysis and replication in a fifth cohort (n = 865). After correction for covariates, the heritability of the common substrate was estimated at 0.50 (standard error 0.18). The top single-nucleotide polymorphism (SNP) rs17076061 was associated with the common substrate at genome-wide significance and replicated, explaining 1.2% of the common substrate variance. This SNP mapped to a locus on chromosome 5q35.2 harboring genes involved in neuronal development and regeneration. In follow-up analyses, rs17076061 was not robustly associated with psychiatric disease, and no overlap was found between the broader genetic architecture of the common substrate and genetic risk for major depressive disorder, bipolar disorder, or schizophrenia. In conclusion, our study identified that common genetic variation indeed influences the common substrate, but that these variants do not directly translate to increased disease risk. Future studies should investigate gene-by-environment interactions and employ functional imaging to understand how salience network structure translates to psychiatric disorder risk.

scholarly journals Association of bisphenol A with puberty timing: a meta-analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hui Meng ◽  
Yunping Zhou ◽  
Yunxia Jiang
Keyword(s):  
Bisphenol A ◽  
Confidence Intervals ◽  
Random Effects ◽  
Strong Correlation ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Study Heterogeneity ◽  
The Relationship ◽  
Prevalence Ratios

AbstractObjectivesThe results of existing studies on bisphenol A (BPA) and puberty timing did not reach a consensus. Thereby we performed this meta-analytic study to explore the association between BPA exposure in urine and puberty timing.MethodsMeta-analysis of the pooled odds ratios (OR), prevalence ratios (PR) or hazards ratios (HR) with 95% confidence intervals (CI) were calculated and estimated using fixed-effects or random-effects models based on between-study heterogeneity.ResultsA total of 10 studies involving 5621 subjects were finally included. The meta-analysis showed that BPA exposure was weakly associated with thelarche (PR: 0.96, 95% CI: 0.93–0.99), while no association was found between BPA exposure and menarche (HR: 0.99, 95% CI: 0.89–1.12; OR: 1.02, 95% CI: 0.73–1.43), and pubarche (OR: 1.00, 95% CI: 0.79–1.26; PR: 1.00, 95% CI: 0.95–1.05).ConclusionsThere was no strong correlation between BPA exposure and puberty timing. Further studies with large sample sizes are needed to verify the relationship between BPA and puberty timing.

scholarly journals Conservative oxygen therapy for critically ill patients: a meta-analysis of randomized controlled trials

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiao-Li Chen ◽  
Bei-Lei Zhang ◽  
Chang Meng ◽  
Hui-Bin Huang ◽  
Bin Du
Keyword(s):  
Sensitivity Analysis ◽  
Randomized Controlled Trials ◽  
Critically Ill Patients ◽  
Oxygen Therapy ◽  
Primary Outcome ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Icu Patients ◽  
Randomized Controlled

Abstract Objective Conservative oxygen strategy is recommended in acute illness while its benefit in ICU patients remains controversial. Therefore, we sought to conduct a systematic review and meta-analysis to examine such oxygen strategies’ effect and safety in ICU patients. Methods We searched PubMed, Embase, and the Cochrane database from inception to Feb 15, 2021. Randomized controlled trials (RCTs) that compared a conservative oxygen strategy to a conventional strategy in critically ill patients were included. Results were expressed as mean difference (MD) and risk ratio (RR) with a 95% confidence interval (CI). The primary outcome was the longest follow-up mortality. Heterogeneity, sensitivity analysis, and publication bias were also investigated to test the robustness of the primary outcome. Results We included seven trials with a total of 5265 patients. In general, the conventional group had significantly higher SpO2 or PaO2 than that in the conservative group. No statistically significant differences were found in the longest follow-up mortality (RR, 1.03; 95% CI, 0.97–1.10; I2=18%; P=0.34) between the two oxygen strategies when pooling studies enrolling subjects with various degrees of hypoxemia. Further sensitivity analysis showed that ICU patients with mild-to-moderate hypoxemia (PaO2/FiO2 >100 mmHg) had significantly lower mortality (RR, 1.24; 95% CI, 1.05–1.46; I2=0%; P=0.01) when receiving conservative oxygen therapy. These findings were also confirmed in other study periods. Additional, secondary outcomes of the duration of mechanical ventilation, the length of stay in the ICU and hospital, change in sequential organ failure assessment score, and adverse events were comparable between the two strategies. Conclusions Our findings indicate that conservative oxygen therapy strategy did not improve the prognosis of the overall ICU patients. The subgroup of ICU patients with mild to moderate hypoxemia might obtain prognosis benefit from such a strategy without affecting other critical clinical results.

Nasal Intermittent Positive Pressure Ventilation versus Continuous Positive Airway Pressure and Apnea of Prematurity: A Systematic Review and Meta-Analysis

2021 ◽  
Author(s):  
Bayane Sabsabi ◽  
Ava Harrison ◽  
Laura Banfield ◽  
Amit Mukerji
Keyword(s):  
Systematic Review ◽  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Primary Outcome ◽  
Positive Pressure Ventilation ◽  
Positive Airway Pressure ◽  
Meta Analysis ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Apnea Of Prematurity

Objective The study aimed to systematically review and analyze the impact of nasal intermittent positive pressure ventilation (NIPPV) versus continuous positive airway pressure (CPAP) on apnea of prematurity (AOP) in preterm neonates. Study Design In this systematic review and meta-analysis, experimental studies enrolling preterm infants comparing NIPPV (synchronized, nonsynchronized, and bi-level) and CPAP (all types) were searched in multiple databases and screened for the assessment of AOP. Primary outcome was AOP frequency per hour (as defined by authors of included studies). Results Out of 4,980 articles identified, 18 studies were included with eight studies contributing to the primary outcome. All studies had a high risk of bias, with significant heterogeneity in definition and measurement of AOP. There was no difference in AOPs per hour between NIPPV versus CPAP (weighted mean difference = −0.19; 95% confidence interval [CI]: −0.76 to 0.37; eight studies, 456 patients). However, in a post hoc analysis evaluating the presence of any AOP (over varying time periods), the pooled odds ratio (OR) was lower with NIPPV (OR: 0.46; 95% CI: 0.32–0.67; 10 studies, 872 patients). Conclusion NIPPV was not associated with decrease in AOP frequency, although demonstrated lower odds of developing any AOP. However, definite recommendations cannot be made based on the quality of the published evidence. Key Points

scholarly journals Efficacy and safety of Si-Jun-Zi-Tang-based therapies for functional (non-ulcer) dyspepsia: a meta-analysis of randomized controlled trials

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yaping Wang ◽  
Bin Liu ◽  
Xiuqiong Fu ◽  
Tiejun Tong ◽  
Zhiling Yu
Keyword(s):  
Relapse Rate ◽  
Large Scale ◽  
Primary Outcome ◽  
Response Rate ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Efficacy And Safety ◽  
History Of ◽  
Non Ulcer Dyspepsia

Abstract Background The traditional Chinese medicine formula Si-Jun-Zi-Tang (SJZT) has a long history of application in the treatment of functional dyspepsia (non-ulcer dyspepsia, FD)-like symptoms. SJZT-based therapies have been claimed to be beneficial in managing FD. This study aimed to assess the efficacy and safety of SJZT-based therapies in treating FD by meta-analysis. Methods Systematic searches for RCTs were conducted in seven databases (up to February 2019) without language restrictions. Data were analyzed using Cochrane RevMan software version 5.3.0 and Stata software version 13.1, and reported as relative risk (RR) or odds ratio (OR) with 95% confidence intervals (CIs). The primary outcome was response rate and the secondary outcomes were gastric emptying, quality of life, adverse effects and relapse rate. The quality of evidence was evaluated according to criteria from the Cochrane risk of bias. Results A total of 341 potentially relevant publications were identified, and 12 RCTs were eligible for inclusion. For the response rate, there was a statically significant benefit in favor of SJZT-based therapies (RR = 1.23; 95% CI 1.17 to 1.30). However, the benefit was limited to modified SJZT (MSJZT). The relapse rate of FD patients received SJZT-based therapies was lower than that of patients who received conventional medicines (OR = 0.23; 95% CI 0.10 to 0.51). No SJZT-based therapies-related adverse effect was reported. Conclusion SJZT-based prescriptions may be effective in treating FD and no serious side-effects were identified, but the effect on response rate appeared to be limited to MSJZT. The results should be interpreted with caution as all the included studies were considered at a high risk of bias. Standardized, large-scale and strictly designed RCTs are needed to further validate the benefits of SJZT-based therapies for FD management. Trial registration Systematic review registration: [PROSPERO registration: CRD42019139136].

scholarly journals Beta-binomial models for meta-analysis with binary outcomes: Variations, extensions, and additional insights from econometrics

2021 ◽  
pp. 263208432199622
Author(s):  
Tim Mathes ◽  
Oliver Kuss
Keyword(s):  
Simulation Study ◽  
Count Data ◽  
Negative Binomial ◽  
Meta Analysis ◽  
Negative Binomial Regression ◽  
Binary Outcomes ◽  
Small Scale ◽  
Panel Count Data ◽  
Count Data Models ◽  
Meta Analyses

Background Meta-analysis of systematically reviewed studies on interventions is the cornerstone of evidence based medicine. In the following, we will introduce the common-beta beta-binomial (BB) model for meta-analysis with binary outcomes and elucidate its equivalence to panel count data models. Methods We present a variation of the standard “common-rho” BB (BBST model) for meta-analysis, namely a “common-beta” BB model. This model has an interesting connection to fixed-effect negative binomial regression models (FE-NegBin) for panel count data. Using this equivalence, it is possible to estimate an extension of the FE-NegBin with an additional multiplicative overdispersion term (RE-NegBin), while preserving a closed form likelihood. An advantage due to the connection to econometric models is, that the models can be easily implemented because “standard” statistical software for panel count data can be used. We illustrate the methods with two real-world example datasets. Furthermore, we show the results of a small-scale simulation study that compares the new models to the BBST. The input parameters of the simulation were informed by actually performed meta-analysis. Results In both example data sets, the NegBin, in particular the RE-NegBin showed a smaller effect and had narrower 95%-confidence intervals. In our simulation study, median bias was negligible for all methods, but the upper quartile for median bias suggested that BBST is most affected by positive bias. Regarding coverage probability, BBST and the RE-NegBin model outperformed the FE-NegBin model. Conclusion For meta-analyses with binary outcomes, the considered common-beta BB models may be valuable extensions to the family of BB models.

scholarly journals Intraosseous versus intravenous vascular access during cardiopulmonary resuscitation for out-of-hospital cardiac arrest: a systematic review and meta-analysis of observational studies

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Yu-Lin Hsieh ◽  
Meng-Che Wu ◽  
Jon Wolfshohl ◽  
James d’Etienne ◽  
Chien-Hua Huang ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cardiopulmonary Resuscitation ◽  
Hospital Discharge ◽  
Vascular Access ◽  
Subgroup Analysis ◽  
Observational Studies ◽  
Primary Outcome ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Hospital Cardiac Arrest

Abstract Introduction This study is aimed to investigate the association of intraosseous (IO) versus intravenous (IV) route during cardiopulmonary resuscitation (CPR) with outcomes after out-of-hospital cardiac arrest (OHCA). Methods We systematically searched PubMed, Embase, Cochrane Library and Web of Science from the database inception through April 2020. Our search strings included designed keywords for two concepts, i.e. vascular access and cardiac arrest. There were no limitations implemented in the search strategy. We selected studies comparing IO versus IV access in neurological or survival outcomes after OHCA. Favourable neurological outcome at hospital discharge was pre-specified as the primary outcome. We pooled the effect estimates in random-effects models and quantified the heterogeneity by the I2 statistics. Time to intervention, defined as time interval from call for emergency medical services to establishing vascular access or administering medications, was hypothesized to be a potential outcome moderator and examined in subgroup analysis with meta-regression. Results Nine retrospective observational studies involving 111,746 adult OHCA patients were included. Most studies were rated as high quality according to Newcastle-Ottawa Scale. The pooled results demonstrated no significant association between types of vascular access and the primary outcome (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27–1.33; I2, 95%). In subgroup analysis, time to intervention was noted to be positively associated with the pooled OR of achieving the primary outcome (OR: 3.95, 95% CI, 1.42–11.02, p: 0.02). That is, when the studies not accounting for the variable of “time to intervention” in the statistical analysis were pooled together, the meta-analytic results between IO access and favourable outcomes would be biased toward inverse association. No obvious publication bias was detected by the funnel plot. Conclusions The meta-analysis revealed no significant association between types of vascular access and neurological outcomes at hospital discharge among OHCA patients. Time to intervention was identified to be an important outcome moderator in this meta-analysis of observation studies. These results call for the need for future clinical trials to investigate the unbiased effect of IO use on OHCA CPR.

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