scholarly journals Metaplot: A new Stata module for assessing heterogeneity in a meta-analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253341
Author(s):  
Jalal Poorolajal ◽  
Shahla Noornejad
Keyword(s):  
Sensitivity Analysis ◽  
Meta Analysis ◽  
Rapid Identification ◽  
Outcome Data ◽  
Continuous Data ◽  
Combinatorial Algorithm ◽  
Graphical Approach ◽  
Standard Tool ◽  
Reporting Heterogeneity ◽  
Substantial Heterogeneity

Background The proposed sequential and combinatorial algorithm, suggested as a standard tool for assessing, exploring, and reporting heterogeneity in the meta-analysis, is useful but time-consuming particularly when the number of included studies is large. Metaplot is a novel graphical approach that facilitates performing sensitivity analysis to distinguish the source of substantial heterogeneity across studies with ease and speed. Method Metaplot is a Stata module based on Stata’s commands, known informally as "ado". Metaplot presents a two-way (x, y) plot in which the x-axis represents the study codes and the y-axis represents the values of I2 statistics excluding one study at a time (n-1 studies). Metaplot also produces a table in the ’Results window’ of the Stata software including details such as I2 and χ2 statistics and their P-values omitting one study in each turn. Results Metaplot allows rapid identification of studies that have a disproportionate impact on heterogeneity across studies, and communicates to what extent omission of that study may reduce the overall heterogeneity based on the I2 and χ2 statistics. Metaplot has no limitations regarding the number of studies or types of outcome data (binomial or continuous data). Conclusions Metaplot is a simple graphical approach that gives a quick and easy identification of the studies having substantial influences on overall heterogeneity at a glance.

scholarly journals Allowing for Informative Missingness in Aggregate Data Meta-Analysis with Continuous or Binary Outcomes: Extensions to Metamiss

2018 ◽  
Vol 18 (3) ◽  
pp. 716-740 ◽  
Author(s):  
Anna Chaimani ◽  
Dimitris Mavridis ◽  
Georgia Salanti ◽  
Julian P. T. Higgins ◽  
Ian R. White
Keyword(s):  
Sensitivity Analysis ◽  
Missing Data ◽  
Randomized Trials ◽  
Meta Analysis ◽  
Outcome Data ◽  
Aggregate Data ◽  
Binary Outcomes ◽  
Continuous Data ◽  
Summary Effect ◽  
The Impact

Missing outcome data can invalidate the results of randomized trials and their meta-analysis. However, addressing missing data is often a challenging issue because it requires untestable assumptions. The impact of missing outcome data on the meta-analysis summary effect can be explored by assuming a relationship between the outcome in the observed and the missing participants via an informative missingness parameter. The informative missingness parameters cannot be estimated from the observed data, but they can be specified, with associated uncertainty, using evidence external to the meta-analysis, such as expert opinion. The use of informative missingness parameters in pairwise meta-analysis of aggregate data with binary outcomes has been previously implemented in Stata by the metamiss command. In this article, we present the new command metamiss2, which is an extension of metamiss for binary or continuous data in pairwise or network meta-analysis. The command can be used to explore the robustness of results to different assumptions about the missing data via sensitivity analysis.

scholarly journals Association between Oral Hygiene and Metabolic Syndrome: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 10 (13) ◽  
pp. 2873
Author(s):  
Cornelia Melinda Adi Santoso ◽  
Fera Ketti ◽  
Taufan Bramantoro ◽  
Judit Zsuga ◽  
Attila Nagy
Keyword(s):  
Systematic Review ◽  
Metabolic Syndrome ◽  
Oral Hygiene ◽  
Reference Lists ◽  
Meta Analysis ◽  
Tooth Brushing ◽  
Inclusion Criteria ◽  
Poor Oral Hygiene ◽  
Dental Visits ◽  
Substantial Heterogeneity

Emerging evidence has linked poor oral hygiene to metabolic syndrome (MetS), but previously, no summary of evidence has been conducted on the topic. This systematic review and meta-analysis aims to evaluate the associations of oral hygiene status and care with MetS. A systematic search of the PubMed and Web of Science databases from inception to March 17, 2021, and examination of reference lists was conducted to identify eligible observational studies. A random-effects model was applied to pool the effects of oral hygiene status and care on MetS. Thirteen studies met the inclusion criteria and had sufficient methodological quality. Good oral hygiene status (OR = 0.30 (0.13–0.66); I2 = 91%), frequent tooth brushing (OR = 0.68 (0.58–0.80); I2 = 89%), and frequent interdental cleaning (OR = 0.89 (0.81–0.99); I2 = 27%) were associated with a lower risk of MetS. Only one study examined the association between dental visits and MetS (OR = 1.10 (0.77–1.55)). Our findings suggested that there might be inverse associations of oral hygiene status, tooth-brushing frequency, and interdental cleaning with MetS. However, substantial heterogeneity for tooth-brushing frequency and inconsistent results for oral hygiene status in subgroup analyses were observed. There was insufficient evidence for the association between dental visits and MetS. Further longitudinal studies are needed to investigate these associations.

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.

scholarly journals Predictive value of pretreatment PD-L1 expression in EGFR-mutant non-small cell lung cancer: a meta-analysis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhiyu Peng ◽  
Huahang Lin ◽  
Ke Zhou ◽  
Senyi Deng ◽  
Jiandong Mei
Keyword(s):  
Lung Cancer ◽  
Sensitivity Analysis ◽  
Small Cell Lung Cancer ◽  
Cell Lung Cancer ◽  
Predictive Value ◽  
Meta Analysis ◽  
Small Cell ◽  
Small Cell Lung ◽  
Egfr Mutant ◽  
Egfr Tkis

Abstract Objective To investigate the predictive value of programmed death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Methods We conducted a systemic search of PubMed, EMBASE, and the Cochrane Library from 1 January 2000 to 30 August 2020, to identify related studies. We combined the hazard ratio (HR) and 95% confidence interval (CI) to assess the correlation of PD-L1 expression with progression-free survival (PFS) and overall survival (OS). We assessed the quality of the included studies by the Newcastle–Ottawa Scale (NOS). We performed subgroup analyses based on immunohistochemistry (IHC) scoring system, IHC antibodies, sample size, countries, and survival analysis mode. Sensitivity analysis and evaluation of publication bias were also performed. Results Twelve studies including 991 patients met the criteria. The mean NOS score was 7.42 ± 1.19. Patients with high PD-L1 expression was associated with poorer PFS (HR = 1.90; 95% CI = 1.16–3.10; P = 0.011), while there was no association between PD-L1 expression and OS (HR = 1.19; 95% CI = 0.99–1.43; P = 0.070). Subgroup analysis prompted IHC scoring systems, IHC antibodies, and sample size have important effects on heterogeneity. The pooled results were robust according to the sensitivity analysis. Conclusions The result of this meta-analysis suggested that PD-L1 expression might be a predictive biomarker for EGFR-mutant non-small cell lung cancer treated with EGFR-TKIs.

scholarly journals Robot-assisted thoracic surgery versus video-assisted thoracic surgery for lung lobectomy or segmentectomy in patients with non-small cell lung cancer: a meta-analysis

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jianglei Ma ◽  
Xiaoyao Li ◽  
Shifu Zhao ◽  
Jiawei Wang ◽  
Wujia Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Sensitivity Analysis ◽  
Thoracic Surgery ◽  
Conversion Rate ◽  
Meta Analysis ◽  
Small Cell ◽  
Small Cell Lung ◽  
Robot Assisted ◽  
Short Term

Abstract Background It remains no clear conclusion about which is better between robot-assisted thoracic surgery (RATS) and video-assisted thoracic surgery (VATS) for the treatment of patients with non-small cell lung cancer (NSCLC). Therefore, this meta-analysis aimed to compare the short-term and long-term efficacy between RATS and VATS for NSCLC. Methods Pubmed, Cochrane Library, Embase, China National Knowledge Infrastructure (CNKI), Medline, and Web of Science databases were comprehensively searched for studies published before December 2020. The quality of the articles was evaluated using the Newcastle-Ottawa Scale (NOS) and the data analyzed using the Review Manager 5.3 software. Fixed or random effect models were applied according to heterogeneity. Subgroup analysis and sensitivity analysis were conducted. Results A total of 18 studies including 11,247 patients were included in the meta-analyses, of which 5114 patients were in the RATS group and 6133 in the VATS group. Compared with VATS, RATS was associated with less blood loss (WMD = − 50.40, 95% CI -90.32 ~ − 10.48, P = 0.010), lower conversion rate (OR = 0.50, 95% CI 0.43 ~ 0.60, P < 0.001), more harvested lymph nodes (WMD = 1.72, 95% CI 0.63 ~ 2.81, P = 0.002) and stations (WMD = 0.51, 95% CI 0.15 ~ 0.86, P = 0.005), shorter duration of postoperative chest tube drainage (WMD = − 0.61, 95% CI -0.78 ~ − 0.44, P < 0.001) and hospital stay (WMD = − 1.12, 95% CI -1.58 ~ − 0.66, P < 0.001), lower overall complication rate (OR = 0.90, 95% CI 0.83 ~ 0.99, P = 0.020), lower recurrence rate (OR = 0.51, 95% CI 0.36 ~ 0.72, P < 0.001), and higher cost (WMD = 3909.87 USD, 95% CI 3706.90 ~ 4112.84, P < 0.001). There was no significant difference between RATS and VATS in operative time, mortality, overall survival (OS), and disease-free survival (DFS). Sensitivity analysis showed that no significant differences were found between the two techniques in conversion rate, number of harvested lymph nodes and stations, and overall complication. Conclusions The results revealed that RATS is a feasible and safe technique compared with VATS in terms of short-term and long-term outcomes. Moreover, more randomized controlled trials comparing the two techniques with rigorous study designs are still essential to evaluate the value of robotic surgery for NSCLC.

scholarly journals Polyethylene glycol versus lactulose in the treatment of hepatic encephalopathy: a systematic review and meta-analysis

2021 ◽  
Vol 8 (1) ◽  
pp. e000648
Author(s):  
Gilles Jadd Hoilat ◽  
Mohamad Fekredeen Ayas ◽  
Judie Noemie Hoilat ◽  
Ahmed Abu-Zaid ◽  
Ceren Durer ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Hepatic Encephalopathy ◽  
Web Of Science ◽  
Meta Analysis ◽  
Standard Of Care ◽  
Brain Dysfunction ◽  
Cochrane Library ◽  
Continuous Data ◽  
Inverse Variance ◽  
Scoring Algorithm

BackgroundHepatic encephalopathy (HE) is defined as brain dysfunction that occurs because of acute liver failure or liver cirrhosis and is associated with significant morbidity and mortality. Lactulose is the standard of care till this date; however, polyethylene glycol (PEG) has gained the attention of multiple investigators.MethodsWe screened five databases namely PubMed, Scopus, Web of Science, Cochrane Library and Embase from inception to 10 February 2021. Dichotomous and continuous data were analysed using the Mantel-Haenszel and inverse variance methods, respectively, which yielded a meta-analysis comparing PEG versus lactulose in the treatment of HE.ResultsFour trials with 229 patients were included. Compared with lactulose, the pooled effect size demonstrated a significantly lower average HE Scoring Algorithm (HESA) Score at 24 hours (Mean difference (MD)=−0.68, 95% CI (−1.05 to –0.31), p<0.001), a higher proportion of patients with reduction of HESA Score by ≥1 grade at 24 hours (risk ratio (RR)=1.40, 95% CI (1.17 to 1.67), p<0.001), a higher proportion of patients with a HESA Score of grade 0 at 24 hours (RR=4.33, 95% CI (2.27 to 8.28), p<0.0010) and a shorter time to resolution of HE group (MD=−1.45, 95% CI (−1.72 to –1.18), p<0.001) in favour of patients treated with PEG.ConclusionPEG leads to a higher drop in the HESA Score and thus leads to a faster resolution of HE compared with lactulose.

scholarly journals Does Neonatal Imitation Exist? Insights From a Meta-Analysis of 336 Effect Sizes

2021 ◽  
pp. 174569162095983
Author(s):  
Jacqueline Davis ◽  
Jonathan Redshaw ◽  
Thomas Suddendorf ◽  
Mark Nielsen ◽  
Siobhan Kennedy-Costantini ◽  
...  
Keyword(s):  
Social Behavior ◽  
Positive Result ◽  
Human Development ◽  
Degrees Of Freedom ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Significant Evidence ◽  
The Past ◽  
Substantial Heterogeneity

Neonatal imitation is a cornerstone in many theoretical accounts of human development and social behavior, yet its existence has been debated for the past 40 years. To examine possible explanations for the inconsistent findings in this body of research, we conducted a multilevel meta-analysis synthesizing 336 effect sizes from 33 independent samples of human newborns, reported in 26 articles. The meta-analysis found significant evidence for neonatal imitation ( d = 0.68, 95% CI = [0.39, 0.96], p < .001) but substantial heterogeneity between study estimates. This heterogeneity was not explained by any of 13 methodological moderators identified by previous reviews, but it was associated with researcher affiliation, test of moderators ( QM) (15) = 57.09, p < .001. There are at least two possible explanations for these results: (a) Neonatal imitation exists and its detection varies as a function of uncaptured methodological factors common to a limited set of studies, and (2) neonatal imitation does not exist and the overall positive result is an artifact of high researcher degrees of freedom.

In Reply: Dexamethasone Therapy For Bacterial Meningitis

PEDIATRICS ◽  
1996 ◽  
Vol 97 (2) ◽  
pp. 287-287 ◽  
Author(s):  
ELLEN R. WALD
Keyword(s):  
Bacterial Meningitis ◽  
Meta Analysis ◽  
Bacterial Species ◽  
The United States ◽  
Generation Cephalosporin ◽  
Outcome Data ◽  
Haemophilus Influenzae Type ◽  
Double Blind ◽  
Dexamethasone Therapy ◽  
Meningitis In Children

Dr Bonadio has combined outcome data from four prospective, randomized, double-blind, placebo-controlled trials assessing the effect of adjunctive corticosteroid therapy on the outcome of bacterial meningitis in children treated with a third-generation cephalosporin. Similar to the previously published meta-analysis included in the article by Schaad et al, Dr Bonadio's analysis includes all etiologies of bacterial meningitis without clarifying whether a beneficial effect applies to particular bacterial species. Fifty-two to 82% of cases in each of the trials were comprised of Haemophilus influenzae type b, a bacterial species that is now a rare cause of meningitis in the United States.

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