keyword
MENU ▼
Read by QxMD icon Read
search

Weight bias

keyword
https://www.readbyqxmd.com/read/28211076/comparison-of-conditional-bias-adjusted-estimators-for-interim-analysis-in-clinical-trials-with-survival-data
#1
Masashi Shimura, Masahiko Gosho, Akihiro Hirakawa
Group sequential designs are widely used in clinical trials to determine whether a trial should be terminated early. In such trials, maximum likelihood estimates are often used to describe the difference in efficacy between the experimental and reference treatments; however, these are well known for displaying conditional and unconditional biases. Established bias-adjusted estimators include the conditional mean-adjusted estimator (CMAE), conditional median unbiased estimator, conditional uniformly minimum variance unbiased estimator (CUMVUE), and weighted estimator...
February 17, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28211056/targeted-mass-media-interventions-promoting-healthy-behaviours-to-reduce-risk-of-non-communicable-diseases-in-adult-ethnic-minorities
#2
REVIEW
Annhild Mosdøl, Ingeborg B Lidal, Gyri H Straumann, Gunn E Vist
BACKGROUND: Physical activity, a balanced diet, avoidance of tobacco exposure, and limited alcohol consumption may reduce morbidity and mortality from non-communicable diseases (NCDs). Mass media interventions are commonly used to encourage healthier behaviours in population groups. It is unclear whether targeted mass media interventions for ethnic minority groups are more or less effective in changing behaviours than those developed for the general population. OBJECTIVES: To determine the effects of mass media interventions targeting adult ethnic minorities with messages about physical activity, dietary patterns, tobacco use or alcohol consumption to reduce the risk of NCDs...
February 17, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28210936/does-obesity-affect-the-non-invasive-measurement-of-cardiac-output-performed-by-electrical-cardiometry-in-children-and-adolescents
#3
Luis Altamirano-Diaz, Eva Welisch, Ralf Rauch, Michael Miller, Teresa Sohee Park, Kambiz Norozi
Electrical cardiometry (EC) is a non-invasive and inexpensive method for hemodynamic assessment and monitoring. However, its feasibility for widespread clinical use, especially for the obese population, has yet to be determined. In this study, we evaluated the agreement and reliability of EC compared to transthoracic Doppler echocardiography (TTE) in normal, overweight, and obese children and adolescents. We measured stroke volume (SV) and cardiac output (CO) of 131 participants using EC and TTE simultaneously...
February 17, 2017: Journal of Clinical Monitoring and Computing
https://www.readbyqxmd.com/read/28208229/comparing-the-performance-of-propensity-score-methods-in-healthcare-database-studies-with-rare-outcomes
#4
Jessica M Franklin, Wesley Eddings, Peter C Austin, Elizabeth A Stuart, Sebastian Schneeweiss
Nonrandomized studies of treatments from electronic healthcare databases are critical for producing the evidence necessary to making informed treatment decisions, but often rely on comparing rates of events observed in a small number of patients. In addition, studies constructed from electronic healthcare databases, for example, administrative claims data, often adjust for many, possibly hundreds, of potential confounders. Despite the importance of maximizing efficiency when there are many confounders and few observed outcome events, there has been relatively little research on the relative performance of different propensity score methods in this context...
February 16, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28205031/comparable-long-term-oncologic-outcomes-of-laparoscopic-versus-open-pancreaticoduodenectomy-for-adenocarcinoma-a-propensity-score-weighting-analysis
#5
Claudius Conrad, Valeria Basso, Guillaume Passot, Daria Zorzi, Liang Li, Hsiang-Chun Chen, David Fuks, Brice Gayet
BACKGROUND: To date, no study has reported long-term oncologic outcome for patients undergoing laparoscopic pancreaticoduodenectomy (LPD) compared to open surgery (OPD). The aim of this study is assess long-term oncologic outcomes for patients with adenocarcinoma undergoing LPD versus OPD using propensity score weighting modeling to minimize selection bias. PATIENTS AND METHODS: All patients undergoing PD at Institut Mutualiste Montsouris between January 2000 and April 2010 were included...
February 15, 2017: Surgical Endoscopy
https://www.readbyqxmd.com/read/28202779/fasting-mimicking-diet-and-markers-risk-factors-for-aging-diabetes-cancer-and-cardiovascular-disease
#6
Min Wei, Sebastian Brandhorst, Mahshid Shelehchi, Hamed Mirzaei, Chia Wei Cheng, Julia Budniak, Susan Groshen, Wendy J Mack, Esra Guen, Stefano Di Biase, Pinchas Cohen, Todd E Morgan, Tanya Dorff, Kurt Hong, Andreas Michalsen, Alessandro Laviano, Valter D Longo
Calorie restriction or changes in dietary composition can enhance healthy aging, but the inability of most subjects to adhere to chronic and extreme diets, as well as potentially adverse effects, limits their application. We randomized 100 generally healthy participants from the United States into two study arms and tested the effects of a fasting-mimicking diet (FMD)-low in calories, sugars, and protein but high in unsaturated fats-on markers/risk factors associated with aging and age-related diseases. We compared subjects who followed 3 months of an unrestricted diet to subjects who consumed the FMD for 5 consecutive days per month for 3 months...
February 15, 2017: Science Translational Medicine
https://www.readbyqxmd.com/read/28199334/childhood-hematologic-cancer-and-residential-proximity-to-oil-and-gas-development
#7
Lisa M McKenzie, William B Allshouse, Tim E Byers, Edward J Bedrick, Berrin Serdar, John L Adgate
BACKGROUND: Oil and gas development emits known hematological carcinogens, such as benzene, and increasingly occurs in residential areas. We explored whether residential proximity to oil and gas development was associated with risk for hematologic cancers using a registry-based case-control study design. METHODS: Participants were 0-24 years old, living in rural Colorado, and diagnosed with cancer between 2001-2013. For each child in our study, we calculated inverse distance weighted (IDW) oil and gas well counts within a 16...
2017: PloS One
https://www.readbyqxmd.com/read/28197679/contrast-associated-acute-kidney-injury-in-the-critically-ill-systematic-review-and-bayesian-meta-analysis
#8
Stephan Ehrmann, Andrew Quartin, Brian P Hobbs, Vincent Robert-Edan, Cynthia Cely, Cynthia Bell, Genevieve Lyons, Tai Pham, Roland Schein, Yimin Geng, Karim Lakhal, Chaan S Ng
PURPOSE: Critically ill patients, among whom acute kidney injury is common, are often considered particularly vulnerable to iodinated contrast medium nephrotoxicity. However, the attributable incidence remains uncertain given the paucity of observational studies including a control group. This study assessed acute kidney injury incidence attributable to iodinated contrast media in critically ill patients based on new data accounting for sample and effect size and including a control group...
February 14, 2017: Intensive Care Medicine
https://www.readbyqxmd.com/read/28195640/subcutaneous-unfractionated-heparin-for-the-initial-treatment-of-venous-thromboembolism
#9
REVIEW
Lindsay Robertson, James Strachan
BACKGROUND: Venous thromboembolism (VTE) is a prevalent and serious condition. Its medical treatment requires anticoagulation, usually with either unfractionated or low molecular weight heparin (LMWH). Administration of unfractionated heparin (UFH) is usually intravenous (IV) but can be subcutaneous as well. This is an update of a review first published in 2009. OBJECTIVES: To assess the effects of subcutaneous UFH versus intravenous UFH, subcutaneous LMWH or any other anticoagulant drug for the initial treatment of venous thromboembolism...
February 14, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28195189/protective-effect-of-maternal-uteroplacental-insufficiency-on-oxygen-induced-retinopathy-in-offspring-removing-bias-of-premature-birth
#10
Silke Becker, Haibo Wang, Baifeng Yu, Randy Brown, Xiaokun Han, Robert H Lane, M Elizabeth Hartnett
To address the hypothesis that maternal uteroplacental insufficiency (UPI) increases severity of retinopathy of prematurity, we developed a composite rat model of UPI and oxygen-fluctuations and removed premature birth as a confounding factor. Timed-pregnant Sprague-Dawley dams underwent bilateral uterine artery ligation or anesthesia (control) at e19.5. Full-term pups developed in room air (RA) or an oxygen-induced retinopathy (OIR) model. Isolectin-stained retinal flat-mounts were analyzed for percent of areas of avascular/total retina (AVA) and of intravitreal neovascular/total retina (IVNV)...
February 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28190628/reporting-bias-inflates-the-reputation-of-medical-treatments-a-comparison-of-outcomes-in-clinical-trials-and-online-product-reviews
#11
Mícheál de Barra
OBJECTIVES: People often hold unduly positive expectations about the outcomes of medicines and other healthcare products. Here the following explanation is tested: people who have a positive outcome tend to tell more people about their disease/treatment than people with poor or average outcomes. Akin to the file drawer problem in science, this systematically and positively distorts the information available to others. METHOD: If people with good treatment outcomes are more inclined to tell others, then they should also be more inclined to write online medical product reviews...
February 7, 2017: Social Science & Medicine
https://www.readbyqxmd.com/read/28188873/an-improved-fsl-first-pipeline-for-subcortical-gray-matter-segmentation-to-study-abnormal-brain-anatomy-using-quantitative-susceptibility-mapping-qsm
#12
Xiang Feng, Andreas Deistung, Michael G Dwyer, Jesper Hagemeier, Paul Polak, Jessica Lebenberg, Frédérique Frouin, Robert Zivadinov, Jürgen R Reichenbach, Ferdinand Schweser
Accurate and robust segmentation of subcortical gray matter (SGM) nuclei is required in many neuroimaging applications. FMRIB's Integrated Registration and Segmentation Tool (FIRST) is one of the most popular software tools for automated subcortical segmentation based on T1-weighted (T1w) images. In this work, we demonstrate that FIRST tends to produce inaccurate SGM segmentation results in the case of abnormal brain anatomy, such as present in atrophied brains, due to a poor spatial match of the subcortical structures with the training data in the MNI space as well as due to insufficient contrast of SGM structures on T1w images...
February 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28186338/research-review-language-problems-in-children-with-attention-deficit-hyperactivity-disorder-a-systematic-meta-analytic-review
#13
REVIEW
Hannah Korrel, Kathryn L Mueller, Tim Silk, Vicki Anderson, Emma Sciberras
BACKGROUND: Children with Attention-Deficit Hyperactivity Disorder (ADHD) appear to have a higher risk of language problems compared with typically developing children, although the types of language problems experienced are less clear. This review aims to establish the types of language problems experienced by children with ADHD according to systematically reviewed literature and determine the empirical evidence for language problems in children with ADHD compared with non-ADHD controls...
February 10, 2017: Journal of Child Psychology and Psychiatry, and Allied Disciplines
https://www.readbyqxmd.com/read/28185134/cost-effectiveness-models-in-breast-cancer-screening-in-the-general-population-a-systematic-review
#14
REVIEW
Irmgard C Schiller-Frühwirth, Beate Jahn, Marjan Arvandi, Uwe Siebert
BACKGROUND: Many Western countries have long-established population-based mammography screening programs. Prior to implementing these programs, decision-analytic modeling was widely used to inform decisions. OBJECTIVE: The aim of this study was to perform a systematic review of cost-effectiveness models in breast cancer screening in the general population to analyze their structural and methodological approaches. METHODS: A systematic literature search for health economic models was performed in the electronic databases MEDLINE (Ovid), EMBASE, CRD Databases, Cochrane Library, and EconLit in August 2011 with updates in June 2013, April 2015, and November 2016...
February 10, 2017: Applied Health Economics and Health Policy
https://www.readbyqxmd.com/read/28184252/gene-set-analysis-controlling-for-length-bias-in-rna-seq-experiments
#15
Xing Ren, Qiang Hu, Song Liu, Jianmin Wang, Jeffrey C Miecznikowski
BACKGROUND: In gene set analysis, the researchers are interested in determining the gene sets that are significantly correlated with an outcome, e.g. disease status or treatment. With the rapid development of high throughput sequencing technologies, Ribonucleic acid sequencing (RNA-seq) has become an important alternative to traditional expression arrays in gene expression studies. Challenges exist in adopting the existent algorithms to RNA-seq data given the intrinsic difference of the technologies and data...
2017: BioData Mining
https://www.readbyqxmd.com/read/28183444/effects-of-lifestyle-interventions-on-clinical-characteristics-of-patients-with-non-alcoholic-fatty-liver-disease-a-meta-analysis
#16
Christina N Katsagoni, Michael Georgoulis, George V Papatheodoridis, Demosthenes B Panagiotakos, Meropi D Kontogianni
BACKGROUND/OBJECTIVES: Although lifestyle modifications remain the cornerstone therapy for non-alcoholic fatty liver disease (NAFLD), the optimal lifestyle intervention is still controversial. The aim of this meta-analysis was to evaluate the effect of exercise and/or dietary interventions, type or intensity of exercise and type of diet, on liver function outcomes (liver enzymes, intrahepatic fat and liver histology), as well as on anthropometric and glucose metabolism parameters in NAFLD patients...
March 2017: Metabolism: Clinical and Experimental
https://www.readbyqxmd.com/read/28183157/improve-efficiency-and-reduce-bias-of-cox-regression-models-for-two-stage-randomization-designs-using-auxiliary-covariates
#17
Xue Yang, Yong Zhou
Two-stage randomization designs are broadly accepted and becoming increasingly popular in clinical trials for cancer and other chronic diseases to assess and compare the effects of different treatment policies. In this paper, we propose an inferential method to estimate the treatment effects in two-stage randomization designs, which can improve the efficiency and reduce bias in the presence of chance imbalance of a robust covariate-adjustment without additional assumptions required by Lokhnygina and Helterbrand (Biometrics, 63:422-428)'s inverse probability weighting (IPW) method...
February 9, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28182249/fixed-dose-subcutaneous-low-molecular-weight-heparins-versus-adjusted-dose-unfractionated-heparin-for-the-initial-treatment-of-venous-thromboembolism
#18
REVIEW
Lindsay Robertson, Lauren E Jones
BACKGROUND: Low molecular weight heparins (LMWHs) have been shown to be effective and safe in preventing venous thromboembolism (VTE). They may also be effective for the initial treatment of VTE. This is the third update of the Cochrane Review first published in 1999. OBJECTIVES: To evaluate the efficacy and safety of fixed dose subcutaneous low molecular weight heparin compared to adjusted dose unfractionated heparin (intravenous or subcutaneous) for the initial treatment of people with venous thromboembolism (acute deep venous thrombosis or pulmonary embolism)...
February 9, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28181936/study-design-rigor-in-animal-experimental-research-published-in-anesthesia-journals
#19
Janine M Hoerauf, Angela F Moss, Ana Fernandez-Bustamante, Karsten Bartels
BACKGROUND: Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals...
February 8, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28178966/the-contribution-from-psychological-social-and-organizational-work-factors-to-risk-of-disability-retirement-a-systematic-review-with-meta-analyses
#20
Stein Knardahl, Håkon A Johannessen, Tom Sterud, Mikko Härmä, Reiner Rugulies, Jorma Seitsamo, Vilhelm Borg
BACKGROUND: Previous studies indicate that psychological, social, and organizational factors at work contribute to health, motivation, absence from work, and functional ability. The objective of the study was to assess the current state of knowledge of the contribution of psychological, social, and organizational factors to disability retirement by a systematic review and meta-analyses. METHODS: Data sources: A systematic literature search for studies of retirement due to disability in Medline, Embase, and PsychINFO was performed...
February 8, 2017: BMC Public Health
keyword
keyword
27264
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"