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Missing hypothesis

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https://www.readbyqxmd.com/read/28651410/-application-of-tipping-point-analysis-to-address-missing-data-in-clinical-studies
#1
S J Zhang, Y Wang, W Li
To use a visualized method, tipping-point analysis to address missing data in clinical study and discuss related problems. All the possible outcomes caused by missing data were listed and the tipping points where P-values of hypothesis test changed at 0.05 significant level were found out, then the ratio of P<0.05 was calculated, reflecting the reliability of the study's result. Tipping-point analysis can be applied to both continuous and binary data to help find points where p-values are changed. The area of P<0...
May 10, 2017: Zhonghua Liu Xing Bing Xue za Zhi, Zhonghua Liuxingbingxue Zazhi
https://www.readbyqxmd.com/read/28650972/contribution-of-cognitive-performance-and-cognitive-decline-to-associations-between-socioeconomic-factors-and-dementia-a-cohort-study
#2
Jennifer Rusmaully, Aline Dugravot, Jean-Paul Moatti, Michael G Marmot, Alexis Elbaz, Mika Kivimaki, Séverine Sabia, Archana Singh-Manoux
BACKGROUND: Socioeconomic disadvantage is a risk factor for dementia, but longitudinal studies suggest that it does not affect the rate of cognitive decline. Our objective is to understand the manner in which socioeconomic disadvantage shapes dementia risk by examining its associations with midlife cognitive performance and cognitive decline from midlife to old age, including cognitive decline trajectories in those with dementia. METHODS AND FINDINGS: Data are drawn from the Whitehall II study (N = 10,308 at study recruitment in 1985), with cognitive function assessed at 4 waves (1997, 2002, 2007, and 2012)...
June 2017: PLoS Medicine
https://www.readbyqxmd.com/read/28649644/constitutional-variants-are-not-associated-with-her2-positive-breast-cancer-results-from-the-signal-phare-clinical-cohort
#3
Xavier Pivot, Gilles Romieu, Pierre Fumoleau, Maria Rios, Hervé Bonnefoi, Thomas Bachelot, Patrick Soulié, Christelle Jouannaud, Hugues Bourgeois, Thierry Petit, Isabelle Tennevet, David Assouline, Marie-Christine Mathieu, Jean-Philippe Jacquin, Sandrine Lavau-Denes, Ariane Darut-Jouve, Jean-Marc Ferrero, Carole Tarpin, Christelle Lévy, Valérie Delecroix, Véronique Trillet-Lenoir, Oana Cojocarasu, Jérôme Meunier, Jean-Yves Pierga, Cécile Agostini, Pierre Kerbrat, Céline Faure-Mercier, Hélène Blanché, Mourad Sahbatou, Anne Boland, Delphine Bacq, Céline Besse, Fabien Calvo, Alexia Renaud, Jean-François Deleuze, Iris Pauporté, Gilles Thomas, David G Cox
Human epidermal growth factor receptor 2-positive breast cancer is a subtype of interest regarding its outcome and the impressive impact of human epidermal growth factor receptor 2 targeted therapy. Constitutional variants may be involved in the aetiology of human epidermal growth factor receptor 2-positive breast cancer, and we propose a case-case study to test the hypothesis that single nucleotide polymorphisms may be associated with human epidermal growth factor receptor 2 status. A Genome-Wide Association Study was used in a cohort of 9836 patients from the SIGNAL/PHARE study (NCT00381901-RECF1098)...
2017: NPJ Breast Cancer
https://www.readbyqxmd.com/read/28643030/hospital-electronic-prescribing-system-implementation-impact-on-discharge-information-communication-and-prescribing-errors-a-before-and-after-study
#4
Pamela Ruth Mills, Anita Elaine Weidmann, Derek Stewart
PURPOSE: The study aimed to test the hypothesis that hospital electronic prescribing and medicine administration system (HEPMA) implementation impacted patient discharge letter quality, nature and frequency of prescribing errors. METHOD: A quasi experimental before and after retrospective case note review was conducted in one United Kingdom district general hospital. The total sample size was 318 (random samples of 159 before and after implementation), calculated to achieve a 10% error reduction with a power of 80% and p < 0...
June 22, 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28640839/assessment-of-recall-error-in-self-reported-food-consumption-histories-among-adults-particularly-delay-of-interviews-decrease-completeness-of-food-histories-germany-2013
#5
Maximilian Gertler, Irina Czogiel, Klaus Stark, Hendrik Wilking
INTRODUCTION: Poor recall during investigations of foodborne outbreaks may lead to misclassifications in exposure ascertainment. We conducted a simulation study to assess the frequency and determinants of recall errors. METHODS: Lunch visitors in a cafeteria using exclusively cashless payment reported their consumption of 13 food servings available daily in the three preceding weeks using a self-administered paper-questionnaire. We validated this information using electronic payment information...
2017: PloS One
https://www.readbyqxmd.com/read/28638197/does-more-data-mean-higher-efficiency-an-experience-from-pre-and-post-treatment-study-with-missing-data
#6
Hongyue Wang, Jing Peng, Juila Z Zheng, Bokai Wang, J X Tu, Changyong Feng
In this paper we compare two moment-based methods which have been widely used to test the hypothesis of no treatment effect in pre- and post-treatment studies with data missing completely at random. Our theoretical derivation and simulation results show that the method based on all available data is not necessarily more efficient than the method that uses only complete data pairs. We propose an optimal linear combination of these two methods which turns to be more powerful in all cases.
August 25, 2016: Shanghai Archives of Psychiatry
https://www.readbyqxmd.com/read/28637401/relationship-between-ambulatory-arterial-stiffness-index-aasi-and-night-day-blood-pressure-ratio-in-essential-hypertensives
#7
Domenico Di Raimondo, Alessandra Casuccio, Rosangela Di Liberti, Gaia Musiari, Valentina Zappulla, Alessandra D'angelo, Antonio Pinto
BACKGROUND: Ambulatory Arterial Stiffness Index (AASI) has been proposed as an indirect and simpler method to estimate the Arterial Stiffness (AS). AASI, calculated from a set of data collected during a 24-hours ambulatory blood pressure monitoring (ABPM), is defined as 1 minus the regression slope of diastolic on systolic blood pressure (BP) values. For a given increase in diastolic BP, the increase in systolic BP is smaller in a compliant compared to a stiff artery; the stiffer the arterial tree, the closer AASI is to 1...
June 21, 2017: Current Hypertension Reviews
https://www.readbyqxmd.com/read/28628800/increased-internal-femoral-torsion-can-be-regarded-as-a-risk-factor-for-patellar-instability-a-biomechanical-study
#8
Peter Kaiser, Werner Schmoelz, Philip Schoettle, Marit Zwierzina, Christian Heinrichs, Rene Attal
BACKGROUND: Increased internal femoral torsion is regarded as a risk factor for patellar instability. Biomechanical investigations confirming this hypothesis are missing. METHODS: Eight fresh-frozen cadaver knees were tested on a specially designed simulator. Patellar motion and patellofemoral pressure were evaluated for 0°, 10°, and 20° of increased internal and external femoral torsion with native and with transected medial patellofemoral ligaments used to simulate patellar instability...
June 10, 2017: Clinical Biomechanics
https://www.readbyqxmd.com/read/28626899/consideration-of-the-presence-of-inflammation-is-essential-for-interpretation-of-serum-micronutrient-results
#9
Emma Osland
It was with great interest I read the recent contribution by Christie-David and Gunton, 'Vitamin C deficiency and diabetes mellitus - easily missed?' [1], outlining their retrospective cohort study in 11 patients with poorly healing foot ulcers in the setting of diabetes mellitus. Their findings suggest previously unrecognized vitamin C deficiency may have been a contributing factor to the ulcers that were being treated in their clinic; a hypothesis supported by the healing reported to occur within 3 weeks of the commencement of vitamin C replacement [1]...
June 19, 2017: Diabetic Medicine: a Journal of the British Diabetic Association
https://www.readbyqxmd.com/read/28596015/low-grade-and-high-grade-endometrial-stromal-sarcoma-a-national-cancer-database-study
#10
Brandon-Luke L Seagle, Arunima Shilpi, Samuel Buchanan, Chelain Goodman, Shohreh Shahabi
OBJECTIVE: To provide refined prognostic information from large cohorts of women with low-grade or high-grade endometrial stromal sarcoma (ESS). METHODS: We performed an observational retrospective cohort analysis of women diagnosed with low-grade or high-grade ESS from the 1998-2013 National Cancer Database. Kaplan-Meier and multivariable accelerated failure time survival analyses were performed to identify prognostic factors after multiple imputation of missing data...
June 5, 2017: Gynecologic Oncology
https://www.readbyqxmd.com/read/28594783/progestogens-for-maintenance-tocolysis-in-women-with-a-short-cervix-a-randomized-controlled-trial
#11
Fabio Facchinetti, Patrizia Vergani, Mariarosaria Di Tommaso, Luca Marozio, Barbara Acaia, Roberto Vicini, Lucrezia Pignatti, Anna Locatelli, Marina Spitaleri, Chiara Benedetto, Barbara Zaina, Roberto DʼAmico
OBJECTIVE: To assess the efficacy of progestogens for maintenance tocolysis in women undelivered after their first preterm labor episode. METHODS: Women with singleton pregnancies between 22 0/7 and 31 6/7 weeks of gestation with arrested preterm labor and a cervical length 25 mm or less at hospital discharge were eligible. Patients with a previous preterm birth were excluded. In a randomized controlled trial conducted in five university hospitals, women were randomized to receive vaginal progesterone (200 mg per day) or intramuscular 17α-hydroxyprogesterone caproate (341 mg per week) or to an observation groups (control group)...
June 6, 2017: Obstetrics and Gynecology
https://www.readbyqxmd.com/read/28570290/secondary-data-analysis-techniques-for-comparing-interventions-and-their-limitations
#12
Alexander P Cole, Quoc-Dien Trinh
PURPOSE OF REVIEW: Secondary data analysis has become increasingly common in health services research, specifically comparative effectiveness research. While a comprehensive study of the techniques and methods for secondary data analysis is a wide-ranging topic, we sought to perform a descriptive study of some key methodological issues related to secondary data analyses and to provide a basic summary of techniques to address them. RECENT FINDINGS: In this study, we first address common issues seen in analysis of secondary datasets, and limitations of datasets with respect to bias...
July 2017: Current Opinion in Urology
https://www.readbyqxmd.com/read/28558722/phylogenomic-analyses-of-crassiclitellata-support-major-northern-and-southern-hemisphere-clades-and-a-pangaean-origin-for-earthworms
#13
Frank E Anderson, Bronwyn W Williams, Kevin M Horn, Christer Erséus, Kenneth M Halanych, Scott R Santos, Samuel W James
BACKGROUND: Earthworms (Crassiclitellata) are a diverse group of annelids of substantial ecological and economic importance. Earthworms are primarily terrestrial infaunal animals, and as such are probably rather poor natural dispersers. Therefore, the near global distribution of earthworms reflects an old and likely complex evolutionary history. Despite a long-standing interest in Crassiclitellata, relationships among and within major clades remain unresolved. METHODS: In this study, we evaluate crassiclitellate phylogenetic relationships using 38 new transcriptomes in combination with publicly available transcriptome data...
May 30, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28555299/life-with-one-kidney
#14
Michiel F Schreuder
Life with a solitary functioning kidney (SFK) may be different from that when born with two kidneys. Based on the hyperfiltration hypothesis, a SFK may lead to glomerular damage with hypertension, albuminuria and progression towards end-stage renal disease. As the prognosis of kidney donors was considered to be very good, having a SFK has been considered to be a benign condition. In contrast, our research group has demonstrated that being born with or acquiring a SFK in childhood results in renal injury before adulthood in over 50% of those affected...
May 29, 2017: Pediatric Nephrology: Journal of the International Pediatric Nephrology Association
https://www.readbyqxmd.com/read/28549993/evolution-of-thyroid-hormone-signaling-in-animals-non-genomic-and-genomic-modes-of-action
#15
REVIEW
Elias Taylor, Andreas Heyland
Much research has focused on vertebrate thyroid hormone (TH) synthesis and their function in development and metabolism. While important differences in TH synthesis and signaling exist, comparative studies between vertebrates fail to explain the evolutionary origins of this important regulatory axis. For that, one needs to make sense out of the diverse TH effects which have been described in invertebrate phyla but for which a mechanistic understanding is largely missing. Almost every major group of non-vertebrate animals possesses the capability to synthesize and metabolize thyroid hormones and there is evidence for a nuclear thyroid hormone receptor mediated mechanism in the bilateria, especially in molluscs, echinoderms, cephalochordates and ascidians...
May 23, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/28549268/modulation-of-hpa-axis-response-to-social-stress-in-schizophrenia-by-childhood-trauma
#16
Claudia Lange, Christian G Huber, Daniela Fröhlich, Stefan Borgwardt, Undine E Lang, Marc Walter
HPA axis functioning plays an important role in the etiology of schizophrenia spectrum disorders (SSD). However, only few studies have examined HPA axis responsivity to psychosocial stress in SSD, and results are heterogeneous. Furthermore, childhood trauma is known to influence psychopathology and treatment outcome in SSD, but studies on the influence of childhood trauma on stress related HPA axis activity are missing. The purpose of this study was to investigate cortisol response to a psychosocial stress challenge in SSD patients, and to examine its association with severity of childhood trauma...
May 20, 2017: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/28542692/association-between-undetected-10-2-visual-field-damage-and-vision-related-quality-of-life-in-patients-with-glaucoma
#17
Dana M Blumberg, Carlos Gustavo De Moraes, Alisa J Prager, Qi Yu, Lama Al-Aswad, George A Cioffi, Jeffrey M Liebmann, Donald C Hood
Importance: Recent evidence supports the presence of macular damage (within 8° of the central field) to retinal ganglion cells and associated central visual field (VF) defects in glaucoma, even in early stages. Despite this, to our knowledge, the association of 10-2 VF damage with vision-related quality of life (QOL) has not been well studied. Objective: To determine the association between QOL and visual function as measured by 24-2 and 10-2 VFs in patients with primary open-angle glaucoma and to test the hypothesis that patients with vision-related QOL disproportionate to their 24-2 VF status may exhibit 10-2 damage overlooked by the 24-2 test...
May 25, 2017: JAMA Ophthalmology
https://www.readbyqxmd.com/read/28541075/low-prevalence-search-for-cancers-in-mammograms-evidence-using-laboratory-experiments-and-computer-aided-detection
#18
Melina A Kunar, Derrick G Watson, Sian Taylor-Phillips, Julia Wolska
People miss a large proportion of targets when they only appear rarely. This Low Prevalence (LP) Effect could lead to serious consequences if it occurred in the real-world task of searching for cancers in mammograms. Using a novel mammogram search task, we asked participants to search for a prespecified cancer (Experiments 1-2) or a range of masses (Experiments 3-5) under high or low prevalence conditions. Experiment 1 showed that an LP Effect occurred using these stimuli. Experiment 2 tested an overreliance hypothesis and showed that the use of Computer Aided Detection (CAD) led to fewer missed cancers with a valid CAD prompt yet, a large proportion of cancers were missed when CAD was incorrect...
May 25, 2017: Journal of Experimental Psychology. Applied
https://www.readbyqxmd.com/read/28526889/the-contribution-of-an-asthma-diagnostic-consultation-service-in-obtaining-an-accurate-asthma-diagnosis-for-primary-care-patients-results-of-a-real-life-study
#19
R M E Gillis, W van Litsenburg, R H van Balkom, J W Muris, F W Smeenk
Previous studies showed that general practitioners have problems in diagnosing asthma accurately, resulting in both under and overdiagnosis. To support general practitioners in their diagnostic process, an asthma diagnostic consultation service was set up. We evaluated the performance of this asthma diagnostic consultation service by analysing the (dis)concordance between the general practitioners working hypotheses and the asthma diagnostic consultation service diagnoses and possible consequences this had on the patients' pharmacotherapy...
May 19, 2017: NPJ Primary Care Respiratory Medicine
https://www.readbyqxmd.com/read/28511065/quantifying-the-brain-s-sheet-structure-with-normalized-convolution
#20
Chantal M W Tax, Carl-Fredrik Westin, Tom Dela Haije, Andrea Fuster, Max A Viergever, Evan Calabrese, Luc Florack, Alexander Leemans
The hypothesis that brain pathways form 2D sheet-like structures layered in 3D as "pages of a book" has been a topic of debate in the recent literature. This hypothesis was mainly supported by a qualitative evaluation of "path neighborhoods" reconstructed with diffusion MRI (dMRI) tractography. Notwithstanding the potentially important implications of the sheet structure hypothesis for our understanding of brain structure and development, it is still considered controversial by many for lack of quantitative analysis...
April 4, 2017: Medical Image Analysis
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