scholarly journals Meta-Analysis of Present-Bias Estimation Using Convex Time Budgets*

2020 ◽  
Author(s):  
Taisuke Imai ◽  
Tom A Rutter ◽  
Colin F Camerer
Keyword(s):  
Time Budget ◽  
Meta Analysis ◽  
Primary Source ◽  
Selective Reporting ◽  
Bias Parameter ◽  
Bias Estimation ◽  
Current Time ◽  
Present Bias ◽  
Time Period ◽  
Substantial Heterogeneity

Abstract We examine 220 estimates of the present-bias parameter from 28 articles using the Convex Time Budget protocol. The literature shows that people are on average present-biased, but estimates exhibit substantial heterogeneity across studies. There is evidence of modest selective reporting in the direction of overreporting present-bias. The primary source of heterogeneity is the type of reward, either monetary or non-monetary, but this effect is weakened after correcting for selective reporting. In studies using monetary rewards, the delay until the issue of the reward associated with the “current” time period influences estimates of the present-bias parameter.

scholarly journals Meta-Analysis of Present-Bias Estimation Using Convex Time Budgets

2019 ◽  
Author(s):  
Taisuke Imai ◽  
Tom Rutter ◽  
Colin Camerer
Keyword(s):  
Time Budget ◽  
Meta Analysis ◽  
Primary Source ◽  
Monetary Reward ◽  
Selective Reporting ◽  
Bias Parameter ◽  
Bias Estimation ◽  
Current Time ◽  
Present Bias ◽  
Time Period

We examine 220 estimates of the present-bias parameter from 28 articles using the Convex Time Budget protocol. The literature shows that people are on average present biased, but the estimates exhibit substantial heterogeneity across studies. There is evidence of modest selective reporting in the direction of overreporting present-bias. The primary source of the heterogeneity is the type of reward, either monetary or non-monetary reward, but the effect is weakened after correcting for potential selective reporting. In the studies using the monetary reward, the delay until the issue of the reward associated with the "current" time period is shown to influence the estimates of present bias parameter.

scholarly journals Meta-Analysis of Present-Bias Estimation Using Convex Time Budgets

2019 ◽  
Author(s):  
Taisuke Imai ◽  
Tom A. Rutter ◽  
Colin F. Camerer
Keyword(s):  
Meta Analysis ◽  
Time Budgets ◽  
Bias Estimation ◽  
Present Bias

Power-Enhanced Funnel Plots for Meta-Analysis

2020 ◽  
Vol 228 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Michael Kossmeier ◽  
Ulrich S. Tran ◽  
Martin Voracek
Keyword(s):  
Statistical Power ◽  
Meta Analysis ◽  
Relevant Information ◽  
Selective Reporting ◽  
Graphical Display ◽  
Funnel Plot ◽  
Evidential Value ◽  
Graphical Displays ◽  
Funnel Plots ◽  
Meta Analyses

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.

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 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.

META-ANALYSIS ON ETIOPATHOGENESIS OF SMALL BOWEL OBSTRUCTION IN THE DEPARTMENT OF GEN. SURGERY P.M.C.H. & K.M.C.H., BIHAR

2021 ◽  
pp. 1-3
Author(s):  
Abhishek Chaudhary ◽  
Kanchan Sone Lal Baitha ◽  
Yasir Tajdar
Keyword(s):  
Small Intestine ◽  
Small Bowel ◽  
Abdominal Surgery ◽  
Intestinal Obstruction ◽  
Small Bowel Obstruction ◽  
Bowel Obstruction ◽  
Meta Analysis ◽  
Ileocaecal Valve ◽  
Time Period ◽  
Ligament Of Treitz

Background:The small intestine is the longest and convoluted portion in the digestive tract. It starts from pylorus and ends at ileocaecal valve. The small bowel consists of three parts measuring about 5 to 6 meters. The rst 25cm is the duodenum. Out of the rest part of small gut, jejunum th th. constitute the proximal 2/5 and ileum distal 3/5 The jejunum and ileum extend from the peritoneal fold that supports the duodeno-jejunal junction (Ligament of Treitz) down to ileocaecal valve. Material and Methods:All the patients admitted to PMCH, Patna and KMC, Katihar as intestinal obstruction was included for the study. The time period of study was from October 2014 to November 2016 in PMCH and December 2016 to January 2019 in KMC, Katihar. Out of all Intestinal obstruction 59 cases only of adult small gut obstruction were recorded for comparison and conclusive study.Conclusion: Small bowel obstruction remains a frequently encountered problem in abdominal surgery. Although modern day surgical management continues to focus appropriately on avoiding delayed operation, whatever surgery is indicated, not every patient is always best served by immediate operation

scholarly journals The Sleep Benefit in Episodic Memory: An Integrative Review and a Meta-Analysis

2022 ◽  
Author(s):  
Sabrina Berres ◽  
Edgar Erdfelder
Keyword(s):  
Episodic Memory ◽  
Meta Analysis ◽  
Systematic Investigation ◽  
Cued Recall ◽  
Integrative Review ◽  
Selective Reporting ◽  
Potential Threat ◽  
Sleep Study ◽  
Sleep Benefit ◽  
Variance Estimates

People recall more information after sleep than after an equally long period of wakefulness. This sleep benefit in episodic memory has been documented in almost a century of research. However, an integrative review of hypothesized underlying processes, a comprehensive quantification of the benefit, and a systematic investigation of potential moderators has been missing so far. Here, we address these issues by analyzing 823 effect sizes from 271 independent samples that were reported in 177 articles published between 1967 and 2019. Using multilevel meta-regressions with robust variance estimates, we found a moderate overall sleep benefit in episodic memory (g = 0.44). Moderator analyses revealed four important findings: First, the sleep benefit is larger when stimuli are studied multiple times instead of just once. Second, for word materials, the effect size depends on the retrieval procedure: It is largest in free recall, followed by cued recall and recognition tasks. Third, the sleep benefit is stronger in pre-post difference measures of retention than in delayed memory tests. Fourth, sleep benefits are larger for natural sleep and nighttime naps than foralternative sleep-study designs (e.g., SWS-deprived sleep, daytime naps). Although there was no obvious evidence for selective reporting, it is a potential threat to the validity of the results. When accounting for selective reporting bias, the overall effect of sleep on episodic memory is reduced but still significant (g = 0.28). We argue that our results support an integrative, multi-causal theoretical account of sleep-induced episodic memory benefits and provide guidance to increase their replicability.

scholarly journals Associations of Sedentary Time with Heart Rate and Heart Rate Variability in Adults: A Systematic Review and Meta-Analysis of Observational Studies

2021 ◽  
Vol 18 (16) ◽  
pp. 8508
Author(s):  
Abdullah Bandar Alansare ◽  
Lauren C. Bates ◽  
Lee Stoner ◽  
Christopher E. Kline ◽  
Elizabeth Nagle ◽  
...  
Keyword(s):  
Systematic Review ◽  
Heart Rate ◽  
English Language ◽  
Sedentary Time ◽  
Meta Analysis ◽  
Qualitative Synthesis ◽  
Cross Sectional ◽  
Inverse Variance ◽  
Observational Design ◽  
Substantial Heterogeneity

Purpose: To evaluate if sedentary time (ST) is associated with heart rate (HR) and variability (HRV) in adults. Methods: We systematically searched PubMed and Google Scholar through June 2020. Inclusion criteria were observational design, humans, adults, English language, ST as the exposure, resting HR/HRV as the outcome, and (meta-analysis only) availability of the quantitative association with variability. After qualitative synthesis, meta-analysis used inverse variance heterogeneity models to estimate pooled associations. Results: Thirteen and eight articles met the criteria for the systematic review and meta-analysis, respectively. All studies were cross-sectional and few used gold standard ST or HRV assessment methodology. The qualitative synthesis suggested no associations between ST and HR/HRV. The meta-analysis found a significant association between ST and HR (β = 0.24 bpm per hour ST; CI: 0.10, 0.37) that was stronger in males (β = 0.36 bpm per hour ST; CI: 0.19, 0.53). Pooled associations between ST and HRV indices were non-significant (p > 0.05). Substantial heterogeneity was detected. Conclusions: The limited available evidence suggests an unfavorable but not clinically meaningful association between ST and HR, but no association with HRV. Future longitudinal studies assessing ST with thigh-based monitoring and HRV with electrocardiogram are needed.

scholarly journals Epidemiological evidence relating environmental smoke to COPD in lifelong non-smokers: a systematic review

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 146 ◽  
Author(s):  
Peter N. Lee ◽  
Barbara A. Forey ◽  
Katharine J. Coombs ◽  
Jan S. Hamling ◽  
Alison J. Thornton
Keyword(s):  
Meta Analysis ◽  
Middle Eastern ◽  
Epidemiological Data ◽  
Case Control ◽  
Chronic Obstructive ◽  
Exposure Index ◽  
Bias Estimation ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Main Index

Background: Some evidence suggests environmental tobacco smoke (ETS) might cause chronic obstructive pulmonary disease (COPD). We reviewed available epidemiological data in never smokers. Methods: We identified epidemiological studies providing estimates of relative risk (RR) with 95% confidence interval (CI) for various ETS exposure indices. Confounder-adjusted RRs for COPD were extracted, or derived using standard methods. Meta-analyses were conducted for each exposure index, with tests for heterogeneity and publication bias. For the main index (spouse ever smoked or nearest equivalent), analyses investigated variation in RR by location, publication period, study type, sex, diagnosis, study size, confounder adjustment, never smoker definition, and exposure index definition. Results: Twenty-eight relevant studies were identified; nine European or Middle Eastern, nine Asian, eight American and two from multiple countries. Five were prospective, seven case-control and 16 cross-sectional. The COPD definition involved death or hospitalisation in seven studies, GOLD stage 1+ criteria in twelve, and other definitions in nine. For the main index, random-effects meta-analysis of 33 heterogeneous (p<0.001) estimates gave a RR of 1.20 (95%CI 1.08-1.34). Higher estimates for females (1.59,1.16-2.19, n=11) than males (1.29,0.94-1.76, n=7) or sexes combined (1.10,0.99-1.22, n=15 where sex-specific not available), and lower estimates for studies of 150+ cases (1.08,0.97-1.20, n=13) partly explained the heterogeneity. Estimates were higher for Asian studies (1.34,1.08-1.67, n=10), case-control studies (1.55,1.04-2.32, n=8), and COPD mortality or hospitalisation (1.40,1.12-1.74, n=11). Some increase was seen for severer COPD (1.29,1.10-1.52, n=7). Dose-response evidence was heterogeneous. Evidence for childhood (0.88,0.72-1.07, n=2) and workplace (1.12,0.77-1.64, n=4) exposure was limited, but an increase was seen for overall adulthood exposure (1.20,1.03-1.39, n=17). We discuss study weaknesses that may bias estimation of the association of COPD with ETS. Conclusions: Although the evidence suggests ETS increases COPD, study weaknesses and absence of well-designed large studies precludes reliable inference of causality. More definitive evidence is required.

The correlation between serum Ca-125 level and clinical pregnancy in in vitro fertilization (IVF): A meta-analysis

2019 ◽  
Author(s):  
Xin-Lei Wang ◽  
Zhuo Li ◽  
Han Zhang ◽  
Ce Shi ◽  
Tong Tong ◽  
...  
Keyword(s):  
In Vitro Fertilization ◽  
Embryo Transfer ◽  
Meta Analysis ◽  
Clinical Pregnancy ◽  
Ca 125 ◽  
Vitro Fertilization ◽  
Time Period ◽  
Central Register ◽  
Significant Difference

Abstract Background Several studies had investigated the role of serum Ca-125 in clinical pregnancy of patients undergoing in vitro fertilization (IVF); however, their conclusions had been inconsistent. This study aimed to evaluate the correlation between serum Ca-125 level and clinical pregnancy in IVF.Methods We systematically review the studies in the databases of Mediline OvidSP, EMBASE OvidSP and Cochrane (CENTRAL Central Register of Controlled Trials). Studies on the correlation between serum Ca-125 level and clinical pregnancy in patients underging IVF with or without Intracytoplasmic sperm injection (ICSI) were considered. The pooled standardized mean difference (SMD) with 95% confidence intervals (CIs) was used in the analysis.Results Seven studies involving 558 patients were included. The meta-analysis showed that there was no significant difference in the serum Ca-125 level before embryo transfer (ET) between clinical pregnant group and nonpregnant group (SMD 0.72; 95% CI [0.01, 1.43], P = 0.05, I 2 = 88%), and the same conclusion was also reached in patients without endometriosis (SMD 0.31; 95% CI [-0.53, 1.16], P = 0.47, I 2 = 89%); However, after embryo transfer, the result showed that the Ca-125 level has a small but significantly increase in the clinical pregnant group than in the nonpregnant group (SMD 0.39; 95% CI [0.09, 0.69], P = 0.01, I 2 = 0%).Conclusions Berore ET, there was no significant correlation between serum Ca-125 level and clinical pregnancy in IVF; After ET, the Ca-125 level has a small but significantly increase in the clinical pregnant group than in the nonpregnant group, and it might reflect a successful interaction between the embryo and the endometrium in that time period.

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