Effects on Road Safety of Converting Intersections to Roundabouts: Review of Evidence from Non-U.S. Studies

2003 ◽  
Vol 1847 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Rune Elvik
Keyword(s):  
Road Safety ◽  
Evaluation Studies ◽  
Meta Analysis ◽  
Large Diameter ◽  
Small Diameter ◽  
Traffic Signals ◽  
The United States ◽  
Design Parameters ◽  
Meta Regression Analysis ◽  
Trim And Fill

A meta-analysis of studies reported outside the United States was performed to evaluate the effects on road safety of converting intersections to roundabouts. Twenty-eight studies that provided 113 estimates of effect were evaluated. State-of-the-art techniques of meta-analysis were applied to synthesize evidence from these evaluation studies. A meta-regression analysis was performed, and the possible presence of publication bias was tested and adjusted using the trim-and-fill method. The results show that roundabouts are associated with a 30% to 50% reduction in the number of injury accidents. Fatal accidents are reduced by 50% to 70%. Effects on property damage accidents are highly uncertain, but in three-leg intersections, an increase often will occur. Evidence from the evaluation studies, although highly uncertain, suggests that the effect of roundabouts on injury accidents is greater in four-leg intersections than in three-leg intersections, and it is greater in intersections previously controlled by yield signs than in intersections previously controlled by traffic signals. Few studies have evaluated in detail the effects on safety of design parameters for roundabouts. Findings are inconsistent, but the majority of studies find that small roundabouts (a small diameter of the central traffic island) are safer than large roundabouts (a large diameter of the central traffic island).

The effects of centralizing cancer surgery on postoperative mortality: A systematic review and meta-analysis

2021 ◽  
pp. 135581962110089
Author(s):  
Roberto Grilli ◽  
Federica Violi ◽  
Maria Chiara Bassi ◽  
Massimiliano Marino
Keyword(s):  
Evaluation Studies ◽  
Meta Analysis ◽  
Postoperative Mortality ◽  
Interrupted Time Series ◽  
High Volume ◽  
Cancer Surgery ◽  
Interrupted Time Series Analysis ◽  
Meta Regression ◽  
Meta Regression Analysis ◽  
After Cancer

Objectives To review the evidence of the effects of centralization of cancer surgery on postoperative mortality. Methods We searched Medline, Embase, Cinahl, Cochrane and Scopus (up to November 2019) for studies that (i) assessed the effects of centralization of cancer surgery policies on in-hospital or 30-day mortality, or (ii) described changes in both postoperative mortality for a surgical intervention and degree of centralization using reduction in the number of hospitals or increases in the proportion of patients undergoing cancer surgery at high volume hospitals as proxy. PRISMA guidelines were followed. We estimated pooled odds ratios (OR) and conducted meta-regression to assess the relationship between degree of centralization and mortality. Results A total of 41 studies met our inclusion criteria of which 15 evaluated the effect of centralization policies on postoperative mortality after cancer surgery and 26 described concurrent changes in the degree of centralization and postoperative mortality. Policy evaluation studies mainly used before-after designs (n = 13) or interrupted time series analysis (n = 2), mainly focusing on pancreatic, oesophageal and gastric cancer. All but one showed some degree of reduction in postoperative mortality, with statistically significant effects demonstrated by six studies. The pooled odds ratio for centralization policy effect was 0.68 (95% Confidence interval: 0.54–0.85; I2 = 80%). Meta-regression analysis of the 26 descriptive studies found that an increase of the proportion of patients treated at high volume hospitals was associated with greater reduction in postoperative mortality. Conclusions Centralization of cancer surgery is associated with reduced postoperative mortality. However, existing evidence tends to be of low quality and estimates of the effect size are likely inflated. There is a need for prospective studies using more robust approaches, and for centralization efforts to be accompanied by well-designed evaluations of their effectiveness.

scholarly journals Molecular Investigation of miRNA Biomarkers as Chemoresistance Regulators in Melanoma: A Protocol for Systematic Review and Meta-Analysis

Genes ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 115
Author(s):  
Peter Shaw ◽  
Greg Raymond ◽  
Katherine S. Tzou ◽  
Siddhartha Baxi ◽  
Ravishankar Ram Mani ◽  
...  
Keyword(s):  
Systematic Review ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Cochrane Review ◽  
Bibliographic Databases ◽  
Analysis Model ◽  
Pairwise Correlation ◽  
Meta Regression Analysis ◽  
Trim And Fill ◽  
The Impact

Introduction: Melanoma is a global disease that is predominant in Western countries. However, reliable data resources and comprehensive studies on the theragnostic efficiency of miRNAs in melanoma are scarce. Hence, a decisive study or comprehensive review is required to collate the evidence for profiling miRNAs as a theragnostic marker. This protocol details a comprehensive systematic review and meta-analysis on the impact of miRNAs on chemoresistance and their association with theragnosis in melanoma. Methods and analysis: The articles will be retrieved from online bibliographic databases, including Cochrane Review, EMBASE, MEDLINE, PubMed, Scopus, Science Direct, and Web of Science, with different permutations of ‘keywords’. To obtain full-text papers of relevant research, a stated search method will be used, along with selection criteria. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Protocols 2015 (PRISMA-P) standards were used to create this study protocol. The hazard ratio (HR) with a 95% confidence interval will be analyzed using Comprehensive Meta-Analysis (CMA) software 3.0. (CI). The pooled effect size will be calculated using a random or fixed-effects meta-analysis model. Cochran’s Q test and the I2 statistic will be used to determine heterogeneity. Egger’s bias indicator test, Orwin’s and the classic fail-safe N tests, the Begg and Mazumdar rank collection test, and Duval and Tweedie’s trim and fill calculation will all be used to determine publication bias. The overall standard deviation will be evaluated using Z-statistics. Subgroup analyses will be performed according to the melanoma participants’ clinicopathological and biological characteristics and methodological factors if sufficient studies and retrieved data are identified and available. The source of heterogeneity will be assessed using a meta-regression analysis. A pairwise matrix could be developed using either a pairwise correlation or expression associations of miRNA with patients’ survival for the same studies.

Reliability-Based Limit States Design for Onshore Pipelines

2002 ◽  
Author(s):  
Maher Nessim ◽  
Tom Zimmerman ◽  
Alan Glover ◽  
Martin McLamb ◽  
Brian Rothwell ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Traditional Approach ◽  
Large Diameter ◽  
Small Diameter ◽  
Mechanical Damage ◽  
Design Approach ◽  
Design Parameters ◽  
Pipe Failure ◽  
Limit States ◽  
Current Design

The traditional approach to pipelines design is to select a wall thickness that maintains the hoop stress below the yield strength multiplied by a safety factor. The main design condition implied by this approach is yielding (and by extension burst) of the defect-free pipe. Failure statistics show that this failure mode is virtually impossible as the majority of failures occur due to equipment impact and various types of defects such as corrosion and cracks. Recent investigations show that these failure causes are much more sensitive to wall thickness than to steel grade. As a consequence, current design methods produce variable levels of safety for different pipelines — small-diameter, low-pressure pipelines for example have been shown to have higher failure risks due to mechanical damage than large-diameter, high-pressure pipelines. In addition, the current design approach has been shown to have limited ability to deal with new design parameters, such high steel grades, and unique loading conditions such as frost heave and thaw settlement. The paper shows how these limitations can be addressed by adopting a reliability-based limit states design approach. In this approach, a pipeline is designed to maintain a specified reliability level with respect to its actual expected failure mechanisms (known as limit states). Implementation involves identifying all relevant limit states, selecting target reliability levels that take into account the severity of the failure consequences, and developing a set of design conditions that meet the target reliability levels. The advantages of this approach include lower overall cost for the same safety level, more consistent safety across the range of design parameters, and a built-in ability to address new design situations. Obstacles to its application for onshore pipelines include lack of familiarity with reliability-based approaches and their benefits and lack of consensus on how to define reliability targets. The paper gives an overview of the reliability-based design approach and demonstrates its application using an example involving design for mechanical damage.

Prognostic significance of large diameter proximal aortic neck in endovascular aneurysm repair

VASA ◽  
2020 ◽  
Vol 49 (3) ◽  
pp. 215-224
Author(s):  
George A. Antoniou ◽  
Aws Alfahad ◽  
Stavros A. Antoniou ◽  
Hassan Badri
Keyword(s):  
Meta Analysis ◽  
Large Diameter ◽  
Prognostic Significance ◽  
Endovascular Aneurysm Repair ◽  
Small Diameter ◽  
Aneurysm Rupture ◽  
Random Effects Models ◽  
Late Failure ◽  
Aortic Neck ◽  
Aneurysm Repair

Summary. Background: Adverse morphological features of the proximal aortic neck have been identified as culprits for late failure after endovascular aneurysm repair (EVAR). Our objective was to investigate the prognostic role of wide proximal aortic neck in EVAR. Methods: We conducted a review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies comparing outcomes of EVAR in patients with large versus small proximal aortic neck. A meta-analysis of time-to-event data was performed with the inverse-variance method and the results were reported as summary hazard ratio (HR) and 95 % CI. We applied random-effects models of meta-analysis. Results: We identified 9 observational studies reporting on a total of 7,682 patients (1,961 with large diameter and 5,721 with small diameter neck). The hazard of death (HR 1.57, 95 % CI 1.23–2.01; P = 0.0003), aneurysm-related reintervention (HR 2.06, 95 % CI 1.23–3.45; P = 0.006), type Ia endoleak (HR 6.69, 95 % CI 4.39–10.20; P < 0.001), sac expansion (HR 10.07, 95 % CI 1.80–56.53; P = 0.009), aneurysm rupture (HR 2.96, 95 % CI 2.00–4.38; P < 0.0001), and neck-related adverse events (HR 10.33, 95 % CI 4.95–21.56; P < 0.0001) was higher in patients with large diameter proximal aortic neck than in those with small neck. Conclusions: Patients with a large proximal aortic neck were found to have poorer outcomes than those with small neck. This finding has implications in decision making when selecting methods for aneurysm treatment and in EVAR surveillance for aneurysm-related complications in this cohort of patients.

Pathogen Testing of Ready-to-Eat Meat and Poultry Products Collected at Federally Inspected Establishments in the United States, 1990 to 1999†

2001 ◽  
Vol 64 (8) ◽  
pp. 1188-1193 ◽  
Author(s):  
PRISCILLA LEVINE ◽  
BONNIE ROSE ◽  
STANLEY GREEN ◽  
GERRI RANSOM ◽  
WALTER HILL
Keyword(s):  
United States ◽  
Large Diameter ◽  
Small Diameter ◽  
The United States ◽  
Prevalence Data ◽  
Staphylococcal Enterotoxins ◽  
Poultry Products ◽  
Fermented Sausages ◽  
Luncheon Meat ◽  
Roast Beef

The Food Safety and Inspection Service (FSIS) conducted microbiological testing programs for ready-to-eat (RTE) meat and poultry products produced at approximately 1,800 federally inspected establishments. All samples were collected at production facilities and not at retail. We report results here for the years 1990 through 1999. Prevalence data for Salmonella, Listeria monocytogenes, Escherichia coli O157:H7, or staphylococcal enterotoxins in nine different categories of RTE meat and poultry products are presented and discussed. The prevalence data have certain limitations that restrict statistical inferences, because these RTE product-testing programs are strictly regulatory in nature and not statistically designed. The cumulative 10-year Salmonella prevalences were as follows: jerky, 0.31%; cooked, uncured poultry products, 0.10%; large-diameter cooked sausages, 0.07%; small-diameter cooked sausages, 0.20%; cooked beef, roast beef, and cooked corned beef, 0.22%; salads, spreads, and pâtés, 0.05%; and sliced ham and luncheon meat, 0.22%. The cumulative 3-year Salmonella prevalence for dry and semidry fermented sausages was 1.43%. The cumulative 10-year L. monocytogenes prevalences were as follows: jerky, 0.52%; cooked, uncured poultry products, 2.12%; large-diameter cooked sausages, 1.31%; small-diameter cooked sausages, 3.56%; cooked beef, roast beef, and cooked corned beef, 3.09%; salads, spreads, and pâtés, 3.03%; and sliced ham and luncheon meat, 5.16%. The cumulative 3-year L. monocytogenes prevalence for dry and semidry fermented sausages was 3.25%. None of the RTE products tested for E. coli O157:H7 or staphylococcal enterotoxins was positive. Although FSIS and the industry have made progress in reducing pathogens in these products, additional efforts are ongoing to continually improve the safety of all RTE meat and poultry products manufactured in federally inspected establishments in the United States.

The Evaluation of Reemployment Programs: Between Impact Assessment and Theory-Based Approaches

2014 ◽  
Author(s):  
Arie Glebbeek ◽  
Els Sol
Keyword(s):  
United States ◽  
Evaluation Method ◽  
Evaluation Studies ◽  
Meta Analysis ◽  
Evaluation Research ◽  
The United States ◽  
Black Box ◽  
Evaluation Report ◽  
Mediating Mechanisms ◽  
Meta Analyses

In spite of a much improved labor market, the outcome of a leading evaluation report on reemployment programs in the Netherlands turned out negative. This result might be due to limitations of the evaluation method used by the researchers, who had to content themselves with a nonexperimental approach. Currently, for many evaluation researchers, the experimental method stands out as the superior design, especially when combined with a meta-analysis over several trials. We show, however, that experimental evaluations do not solve the uncertainties in this field. Meta-analyses of evaluation studies in Europe and the United States produced strikingly mixed results. Efforts to trace their diversity to variations in reemployment programs have not been very successful. This is mainly because of the “black box character” of many experimental evaluations, which offer little information about the content of the programs. Following “realistic evaluation,” we argue for a focus on the theories behind these programs in evaluation research. To this end, reemployment services are depicted in twelve core (mediating) mechanisms.

Improving Low-Performing Schools: A Meta-Analysis of Impact Evaluation Studies

2021 ◽  
pp. 000283122110608 ◽  
Author(s):  
Beth E. Schueler ◽  
Catherine Armstrong Asher ◽  
Katherine E. Larned ◽  
Sarah Mehrotra ◽  
Cynthia Pollard
Keyword(s):  
No Child Left Behind ◽  
School Improvement ◽  
English Language ◽  
Evaluation Studies ◽  
Meta Analysis ◽  
The United States ◽  
High Stakes ◽  
Low Performing Schools ◽  
Positive Effects ◽  
K 12

The public narrative surrounding efforts to improve low-performing K–12 schools in the United States has been notably gloomy. But what is known empirically about whether school improvement works, which policies are most effective, which contexts respond best to intervention, and how long it takes? We meta-analyze 141 estimates from 67 studies of post–No Child Left Behind Act turnaround policies. On average, policies had moderate positive effects on math and no effect on English Language Arts achievement on high-stakes exams. We find positive impacts on low-stakes exams and no evidence of harm on nontest outcomes. Extended learning time and teacher replacements predict greater effects. Contexts serving majority-Latina/o populations saw the largest improvements. We cannot rule out publication bias entirely but find no differences between peer-reviewed versus nonpeer-reviewed estimates.

scholarly journals Effects of Prior Antiplatelet Therapy on Mortality, Functional Outcome, and Hematoma Expansion in Intracerebral Hemorrhage: An Updated Systematic Review and Meta-Analysis of Cohort Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Yujie Wu ◽  
Donghang Zhang ◽  
Hongyang Chen ◽  
Bin Liu ◽  
Cheng Zhou
Keyword(s):  
Systematic Review ◽  
Intracerebral Hemorrhage ◽  
Functional Outcome ◽  
Antiplatelet Therapy ◽  
Meta Analysis ◽  
Hematoma Expansion ◽  
Chi Squared ◽  
Meta Regression ◽  
Meta Regression Analysis ◽  
Trim And Fill

Background and Objective: Antiplatelet therapy (APT) is widely used and believed to be associated with increased poor prognosis by promoting bleeding in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to determine whether prior APT is associated with mortality, functional outcome, and hematoma expansion in ICH patients.Methods: The PubMed, Embase, and Web of Science databases were searched for relevant published studies up to December 11, 2020. Univariate and multivariable adjusted odds ratios (ORs) were pooled using a random effects model. Cochran's chi-squared test (Cochran's Q), the I2 statistic, and meta-regression analysis were used to evaluate the heterogeneity. Meta-regression models were developed to explore sources of heterogeneity. Funnel plots were used to detect publication bias. A trim-and-fill method was performed to identify possible asymmetry and assess the robustness of the conclusions.Results: Thirty-one studies fulfilled the inclusion criteria and exhibited a moderate risk of bias. Prior APT users with intracerebral hemorrhage (ICH) had a slightly increased mortality in both univariate analyses [odds ratio (OR) 1.39, 95% CI 1.24–1.56] and multivariable adjusted analyses (OR 1.41, 95% CI 1.21–1.64). The meta-regression indicated that for each additional day of assessment time, the adjusted OR for the mortality of APT patients decreased by 0.0089 (95% CI: −0.0164 to −0.0015; P = 0.0192) compared to that of non-APT patients. However, prior APT had no effects on poor function outcome (pooled univariate OR: 0.99, 95% CI 0.59–1.66; pooled multivariable adjusted OR: 0.93, 95% CI 0.87–1.07) or hematoma growth (pooled univariate OR: 1.23, 95% CI 0.40–3.74, pooled multivariable adjusted OR: 0.94, 95% CI 0.24–3.60).Conclusions: Prior APT was not associated with hematoma expansion or functional outcomes, but there was modestly increased mortality in prior APT patients. Higher mortality of prior APT patients was related to the strong influence of prior APT use on early mortality.Systematic Review Registration:PROSPERO Identifier [CRD42020215243].

Political bullshit receptivity and its correlates: a cross-cultural validation of the concept

2020 ◽  
Author(s):  
Vukašin Gligorić ◽  
Allard Feddes ◽  
Bertjan Doosje
Keyword(s):  
The Netherlands ◽  
Political Ideology ◽  
Voting Behavior ◽  
Free Market ◽  
Meta Analysis ◽  
The United States ◽  
Persuasive Communication ◽  
Lower Probability ◽  
Left Wing ◽  
Total N

Frankfurt defined persuasive communication that has no regard for truth, knowledge, or evidence as bullshit. Although there has been a lot of psychological research on pseudo-profound bullshit, no study examined this type of communication in politics. In the present research, we operationalize political bullshit receptivity as endorsing vague political statements, slogans, and political bullshit programs. We investigated the relationship of these three measures with pseudo-profound bullshit, ideology (political ideology, support for neoliberalism), populism, and voting behavior. Three pre-registered studies in different cultural settings (the United States, Serbia, The Netherlands; total N = 534) yielded medium to high intercorrelations between political bullshit measures and pseudo-profound bullshit, and good construct validity (hypothesized one-factor solution). A Bayesian meta-analysis showed that all political bullshit measures positively correlated with support for the free market, while only some positively correlated with social (political statements and programs) and economic conservatism (programs), and populism (programs). In the U.S., higher receptivity to political bullshit was associated with a higher probability that one voted for Trump (vs Clinton) in the past and higher intentions to vote for Trump (vs Biden and Sanders). In the Netherlands, higher receptivity to political bullshit predicted the intention to vote for the conservative-liberal People's Party for Freedom and Democracy. Exploratory analyses on merged datasets showed that higher receptivity to political bullshit was associated with a higher probability to vote for right-wing candidates/parties and lower probability for the left-wing ones. Overall, political bullshit endorsement showed good validity, opening avenues for research in political communication, especially when this communication is broad and meaningless.

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