2,237 research outputs found
Statistical reproducibility of meta-analysis research claims for medical mask use in community settings to prevent COVID infection
The coronavirus pandemic (COVID) has been an exceptional test of current
scientific evidence that inform and shape policy. Many US states, cities, and
counties implemented public orders for mask use on the notion that this
intervention would delay and flatten the epidemic peak and largely benefit
public health outcomes. P-value plotting was used to evaluate statistical
reproducibility of meta-analysis research claims of a benefit for medical
(surgical) mask use in community settings to prevent COVID infection. Eight
studies (seven meta-analyses, one systematic review) published between 1
January 2020 and 7 December 2022 were evaluated. Base studies were randomized
control trials with outcomes of medical diagnosis or laboratory-confirmed
diagnosis of viral (Influenza or COVID) illness. Self-reported viral illness
outcomes were excluded because of awareness bias. No evidence was observed for
a medical mask use benefit to prevent viral infections in six p-value plots
(five meta-analyses and one systematic review). Research claims of no benefit
in three meta-analyses and the systematic review were reproduced in p-value
plots. Research claims of a benefit in two meta-analyses were not reproduced in
p-value plots. Insufficient data were available to construct p-value plots for
two meta-analyses because of overreliance on self-reported outcomes. These
findings suggest a benefit for medical mask use in community settings to
prevent viral, including COVID infection, is unproven.Comment: 21 pages, 100 references, 3 appendice
Statistical reliability of meta_analysis research claims for gas stove cooking_childhood respiratory health associations
Odds ratios or p_values from individual observational studies can be combined
to examine a common cause_effect research question in meta_analysis. However,
reliability of individual studies used in meta_analysis should not be taken for
granted as claimed cause_effect associations may not reproduce. An evaluation
was undertaken on meta_analysis of base papers examining gas stove cooking,
including nitrogen dioxide, NO2, and childhood asthma and wheeze associations.
Numbers of hypotheses tested in 14 of 27 base papers, 52 percent, used in
meta_analysis of asthma and wheeze were counted. Test statistics used in the
meta_analysis, 40 odds ratios with 95 percent confidence limits, were converted
to p_values and presented in p_value plots. The median and interquartile range
of possible numbers of hypotheses tested in the 14 base papers was 15,360,
6,336_49,152. None of the 14 base papers made mention of correcting for
multiple testing, nor was any explanation offered if no multiple testing
procedure was used. Given large numbers of hypotheses available, statistics
drawn from base papers and used for meta-analysis are likely biased. Even so,
p-value plots for gas stove_current asthma and gas stove_current wheeze
associations show randomness consistent with unproven gas stove harms. The
meta-analysis fails to provide reliable evidence for public health policy
making on gas stove harms to children in North America. NO2 is not established
as a biologically plausible explanation of a causal link with childhood asthma.
Biases_multiple testing and p-hacking_cannot be ruled out as explanations for a
gas stove_current asthma association claim. Selective reporting is another bias
in published literature of gas stove_childhood respiratory health studies.
Keywords gas stove, asthma, meta-analysis, p-value plot, multiple testing,
p_hackingComment: International Journal of Statistics and Probability (2023
Sustainable Mobility for Rural Small University Towns
How can all of the emerging changes in transportation affect a small rural University town? This panel will discuss the opportunities and the drawbacks to automated vehicles, shared vehicles, electric, and solar powered vehicles. The panel will be comprised of various academics and professionals involved with these new transportation changes
LocalControl: An R Package for Comparative Safety and Effectiveness Research
The LocalControl R package implements novel approaches to address biases and confounding when comparing treatments or exposures in observational studies of outcomes. While designed and appropriate for use in comparative safety and effectiveness research involving medicine and the life sciences, the package can be used in other situations involving outcomes with multiple confounders. LocalControl is an open-source tool for researchers whose aim is to generate high quality evidence using observational data. The package implements a family of methods for non-parametric bias correction when comparing treatments in observational studies, including survival analysis settings, where competing risks and/or censoring may be present. The approach extends to bias-corrected personalized predictions of treatment outcome differences, and analysis of heterogeneity of treatment effect-sizes across patient subgroups
Evaluation of Special Event Traffic Management: The Brickyard 400 Case Study
This paper reports on the anonymous tracking of Bluetooth enabled consumer electronic devices to measure the travel time, or space mean speed, of travelers. This sampling technique was deployed at six interstate locations and two signalized arterials in the Indianapolis, IN metropolitan area the week of the NASCAR Brickyard 400. The week prior to the race before data was also collected from a subset of those sites. The day of the race, almost 19,000 unique MAC address were captured at the eight locations. From that information real-time travel time estimates were provided to Indiana Department of Transportation (INDOT) mobile data terminals. After the race, the data was processed to obtain travel time plots and origin destination matrixes to provide a quantitative evaluation of race day traffic management operations. Selected reports and charts from that analysis are discussed in the paper
The Effects of Silicone Contamination on Bond Performance of Various Bond Systems
The sensitivity to silicone contamination of a wide variety of adhesive bond systems is discussed. Generalizations regarding factors that make some bond systems more sensitive to contamination than others are inferred and discussed. The effect of silane adhesion promoting primer on the contamination sensitivity of two epoxy/steel bond systems is also discussed
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