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https://www.readbyqxmd.com/read/28092105/effectiveness-of-water-fluoridation-in-the-prevention-of-dental-caries-across-adult-age-groups
#1
Loc Do, Diep Ha, Marco Peres, John Skinner, Roy Byun, A John Spencer
BACKGROUND: Lifetime access to fluoridated water (FW) is associated with lower caries experience. However, assessing this association in adults is likely affected by age. Cohort stratification and categorization of per cent lifetime access to fluoridated water (% LAFW) within cohorts are current approaches to this assessment. These approaches require an examination of the % LAFW and caries experience variation within and across age groups and their association to inform future analyses...
January 16, 2017: Community Dentistry and Oral Epidemiology
https://www.readbyqxmd.com/read/28088357/joint-genome-wide-prediction-in-several-populations-accounting-for-randomness-of-genotypes-a-hierarchical-bayes-approach-ii-multivariate-spike-and-slab-priors-for-marker-effects-and-derivation-of-approximate-bayes-and-fractional-bayes-factors-for-the-complete
#2
Carlos Alberto Martínez, Kshitij Khare, Arunava Banerjee, Mauricio A Elzo
This study corresponds to the second part of a companion paper devoted to the development of Bayesian multiple regression models accounting for randomness of genotypes in across population genome-wide prediction. This family of models considers heterogeneous and correlated marker effects and allelic frequencies across populations, and has the ability of considering records from non-genotyped individuals and individuals with missing genotypes in any subset of loci without the need for previous imputation, taking into account uncertainty about imputed genotypes...
January 11, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28076925/the-association-between-electronic-bullying-and-school-absenteeism-among-high-school-students-in-the-united-states
#3
Erin Grinshteyn, Y T Yang
BACKGROUND: We examined the relationship between exposure to electronic bullying and absenteeism as a result of being afraid. METHODS: This multivariate, multinomial regression analysis of the 2013 Youth Risk Behavior Survey data assessed the association between experiencing electronic bullying in the past year and how often students were absent in the last month due to feeling unsafe at/in transit to school. The model controlled for other predictors of school absence including demographics, physical/behavioral health, and risk factors...
February 2017: Journal of School Health
https://www.readbyqxmd.com/read/28074600/analyzing-multiple-endpoints-in-a-confirmatory-randomized-clinical-trial-an-approach-that-addresses-stratification-missing-values-baseline-imbalance-and-multiplicity-for-strictly-ordinal-outcomes
#4
Hengrui Sun, Atsushi Kawaguchi, Gary Koch
Confirmatory randomized clinical trials with a stratified design may have ordinal response outcomes, ie, either ordered categories or continuous determinations that are not compatible with an interval scale. Also, multiple endpoints are often collected when 1 single endpoint does not represent the overall efficacy of the treatment. In addition, random baseline imbalances and missing values can add another layer of difficulty in the analysis plan. Therefore, the development of an approach that provides a consolidated strategy to all issues collectively is essential...
January 11, 2017: Pharmaceutical Statistics
https://www.readbyqxmd.com/read/28068910/outcome-sensitive-multiple-imputation-a-simulation-study
#5
Evangelos Kontopantelis, Ian R White, Matthew Sperrin, Iain Buchan
BACKGROUND: Multiple imputation is frequently used to deal with missing data in healthcare research. Although it is known that the outcome should be included in the imputation model when imputing missing covariate values, it is not known whether it should be imputed. Similarly no clear recommendations exist on: the utility of incorporating a secondary outcome, if available, in the imputation model; the level of protection offered when data are missing not-at-random; the implications of the dataset size and missingness levels...
January 9, 2017: BMC Medical Research Methodology
https://www.readbyqxmd.com/read/28065879/structural-zeros-in-high-dimensional-data-with-applications-to-microbiome-studies
#6
Abhishek Kaul, Ori Davidov, Shyamal D Peddada
SUMMARYThis paper is motivated by the recent interest in the analysis of high-dimensional microbiome data. A key feature of these data is the presence of "structural zeros" which are microbes missing from an observation vector due to an underlying biological process and not due to error in measurement. Typical notions of missingness are unable to model these structural zeros. We define a general framework which allows for structural zeros in the model and propose methods of estimating sparse high-dimensional covariance and precision matrices under this setup...
January 8, 2017: Biostatistics
https://www.readbyqxmd.com/read/28065470/the-rare-variant-generalized-disequilibrium-test-for-association-analysis-of-nuclear-and-extended-pedigrees-with-application-to-alzheimer-disease-wgs-data
#7
Zongxiao He, Di Zhang, Alan E Renton, Biao Li, Linhai Zhao, Gao T Wang, Alison M Goate, Richard Mayeux, Suzanne M Leal
Whole-genome and exome sequence data can be cost-effectively generated for the detection of rare-variant (RV) associations in families. Causal variants that aggregate in families usually have larger effect sizes than those found in sporadic cases, so family-based designs can be a more powerful approach than population-based designs. Moreover, some family-based designs are robust to confounding due to population admixture or substructure. We developed a RV extension of the generalized disequilibrium test (GDT) to analyze sequence data obtained from nuclear and extended families...
January 2, 2017: American Journal of Human Genetics
https://www.readbyqxmd.com/read/28057876/academic-performance-in-adolescents-born-after-art-a-nationwide-registry-based-cohort-study
#8
A L Spangmose, S S Malchau, L Schmidt, D Vassard, S Rasmussen, A Loft, J Forman, A Pinborg
STUDY QUESTION: Is academic performance in adolescents aged 15-16 years and conceived after ART, measured as test scores in ninth grade, comparable to that for spontaneously conceived (SC) adolescents? SUMMARY ANSWER: ART singletons had a significantly lower mean test score in the adjusted analysis when compared with SC singletons, yet the differences were small and probably not of clinical relevance. WHAT IS KNOWN ALREADY: Previous studies have shown similar intelligence quotient (IQ) levels in ART and SC children, but only a few have been on adolescents...
January 5, 2017: Human Reproduction
https://www.readbyqxmd.com/read/28056955/development-of-an-algorithm-for-determining-smoking-status-and-behaviour-over-the-life-course-from-uk-electronic-primary-care-records
#9
Mark D Atkinson, Jonathan I Kennedy, Ann John, Keir E Lewis, Ronan A Lyons, Sinead T Brophy
BACKGROUND: Patients' smoking status is routinely collected by General Practitioners (GP) in UK primary health care. There is an abundance of Read codes pertaining to smoking, including those relating to smoking cessation therapy, prescription, and administration codes, in addition to the more regularly employed smoking status codes. Large databases of primary care data are increasingly used for epidemiological analysis; smoking status is an important covariate in many such analyses. However, the variable definition is rarely documented in the literature...
January 5, 2017: BMC Medical Informatics and Decision Making
https://www.readbyqxmd.com/read/28045979/intensive-patient-education-improves-glycaemic-control-in-diabetes-compared-to-conventional-education-a-randomised-controlled-trial-in-a-nigerian-tertiary-care-hospital
#10
Okon Essien, Akaninyene Otu, Victor Umoh, Ofem Enang, Joseph Paul Hicks, John Walley
BACKGROUND: Diabetes is now a global epidemic, but most cases are now in low- and middle-income countries. Diabetes self-management education (DSME) is key to enabling patients to manage their chronic condition and can reduce the occurrence of costly and devastating complications. However, there is limited evidence on the effectiveness of different DSME programmes in resource limited settings. METHODS: We conducted an unblinded, parallel-group, individually-randomised controlled trial at the University of Calabar Teaching Hospital (Nigeria) to evaluate whether an intensive and systematic DSME programme, using structured guidelines, improved glycaemic control compared to the existing ad hoc patient education (clinical practice was unchanged)...
2017: PloS One
https://www.readbyqxmd.com/read/28045978/cord-blood-acute-phase-reactants-predict-early-onset-neonatal-sepsis-in-preterm-infants
#11
Leena B Mithal, Hannah L Palac, Ram Yogev, Linda M Ernst, Karen K Mestan
BACKGROUND: Early onset sepsis (EOS) is a major cause of morbidity and mortality in preterm infants, yet diagnosis remains inadequate resulting in missed cases or prolonged empiric antibiotics with adverse consequences. Evaluation of acute phase reactant (APR) biomarkers in umbilical cord blood at birth may improve EOS detection in preterm infants with intrauterine infection. METHODS: In this nested case-control study, infants (29.7 weeks gestation, IQR: 27.7-32...
2017: PloS One
https://www.readbyqxmd.com/read/28039292/to-condition-or-not-condition-analysing-change-in-longitudinal-randomised-controlled-trials
#12
Cynthia J Coffman, David Edelman, Robert F Woolson
OBJECTIVE: The statistical analysis for a 2-arm randomised controlled trial (RCT) with a baseline outcome followed by a few assessments at fixed follow-up times typically invokes traditional analytic methods (eg, analysis of covariance (ANCOVA), longitudinal data analysis (LDA)). 'Constrained' longitudinal data analysis (cLDA) is a well-established unconditional technique that constrains means of baseline to be equal between arms. We use an analysis of fasting lipid profiles from the Group Medical Clinics (GMC) longitudinal RCT on patients with diabetes to illustrate applications of ANCOVA, LDA and cLDA to demonstrate theoretical concepts of these methods including the impact of missing data...
December 30, 2016: BMJ Open
https://www.readbyqxmd.com/read/28004848/analysing-animal-social-network-dynamics-the-potential-of-stochastic-actor-orientated-models
#13
David N Fisher, Amiyaal Ilany, Matthew J Silk, Tom Tregenza
Animals are embedded in dynamically changing networks of relationships with conspecifics. These dynamic networks are fundamental aspects of their environment, creating selection on behaviours and other traits. However, most social network-based approaches in ecology are constrained to considering networks as static, despite several calls for such analyses to become more dynamic. There are a number of statistical analyses developed in the social sciences that are increasingly being applied to animal networks, of which stochastic actor-oriented models (SAOMs) are a principal example...
December 22, 2016: Journal of Animal Ecology
https://www.readbyqxmd.com/read/28002546/use-of-risk-models-to-predict-death-in-the-next-year-among-individual-ambulatory-patients-with-heart-failure
#14
Larry A Allen, Daniel D Matlock, Susan M Shetterly, Stanley Xu, Wayne C Levy, Laura B Portalupi, Colleen K McIlvennan, Jerry H Gurwitz, Eric S Johnson, David H Smith, David J Magid
Importance: The clinical practice guidelines for heart failure recommend the use of validated risk models to estimate prognosis. Understanding how well models identify individuals who will die in the next year informs decision making for advanced treatments and hospice. Objective: To quantify how risk models calculated in routine practice estimate more than 50% 1-year mortality among ambulatory patients with heart failure who die in the subsequent year. Design, Setting, and Participants: Ambulatory adults with heart failure from 3 integrated health systems were enrolled between 2005 and 2008...
December 21, 2016: JAMA Cardiology
https://www.readbyqxmd.com/read/27995669/perch-a-unified-framework-for-disease-gene-prioritization
#15
Bing-Jian Feng
To interpret genetic variants discovered from next-generation sequencing (NGS), integration of heterogeneous information is vital for success. This paper describes a framework named PERCH (Polymorphism Evaluation, Ranking, and Classification for a Heritable trait), available at http://BJFengLab.org/. It can prioritize disease genes by quantitatively unifying a new deleteriousness measure called BayesDel, an improved assessment of the biological relevance of genes to the disease, a modified linkage analysis, a novel rare-variant association test, and a converted variant call quality score...
December 19, 2016: Human Mutation
https://www.readbyqxmd.com/read/27992328/kronecker-markov-prior-for-dynamic-3d-reconstruction
#16
Tomas Simon, Jack Valmadre, Iain Matthews, Yaser Sheikh
Recovering dynamic 3D structures from 2D image observations is highly under-constrained because of projection and missing data, motivating the use of strong priors to constrain shape deformation. In this paper, we empirically show that the spatiotemporal covariance of natural deformations is dominated by a Kronecker pattern. We demonstrate that this pattern arises as the limit of a spatiotemporal autoregressive process, and derive a Kronecker Markov Random Field as a prior distribution over dynamic structures...
December 13, 2016: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/27927609/data-analysis-protocol-for-the-development-and-evaluation-of-population-pharmacokinetic-models-for-incorporation-into-the-web-accessible-population-pharmacokinetic-service-hemophilia-wapps-hemo
#17
Alanna McEneny-King, Gary Foster, Alfonso Iorio, Andrea N Edginton
BACKGROUND: Hemophilia is an inherited bleeding disorder caused by a deficiency in a specific clotting factor. This results in spontaneous bleeding episodes and eventual arthropathy. The mainstay of hemophilia treatment is prophylactic replacement of the missing factor, but an optimal regimen remains to be determined. Rather, individualized prophylaxis has been suggested to improve both patient safety and resource utilization. However, uptake of this approach has been hampered by the demanding sampling schedules and complex calculations required to obtain individual estimates of pharmacokinetic (PK) parameters...
December 7, 2016: JMIR Research Protocols
https://www.readbyqxmd.com/read/27921315/imputing-estrogen-receptor-er-status-in-a-population-based-cancer-registry-a-sensitivity-analysis
#18
Rebecca Andridge, Anne-Michelle Noone, Nadia Howlader
Breast cancers are clinically heterogeneous based on tumor markers. The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program provides baseline data on these tumor markers for reporting cancer burden and trends over time in the US general population. These tumor markers, however, are often prone to missing observations. In particular, estrogen receptor (ER) status, a key biomarker in the study of breast cancer, has been collected since 1992 but historically was not well-reported, with missingness rates as high as 25% in early years...
December 5, 2016: Statistics in Medicine
https://www.readbyqxmd.com/read/27909127/costs-quality-of-life-and-cost-effectiveness-of-arthroscopic-and-open-repair-for-rotator-cuff-tears-an-economic-evaluation-alongside-the-ukuff-trial
#19
J Murphy, A Gray, C Cooper, D Cooper, C Ramsay, A Carr
AIMS: A trial-based comparison of the use of resources, costs and quality of life outcomes of arthroscopic and open surgical management for rotator cuff tears in the United Kingdom NHS was performed using data from the United Kingdom Rotator Cuff Study (UKUFF) randomised controlled trial. PATIENTS AND METHODS: Using data from 273 patients, healthcare-related use of resources, costs and quality-adjusted life years (QALYs) were estimated at 12 months and 24 months after surgery on an intention-to-treat basis with adjustment for covariates...
December 2016: Bone & Joint Journal
https://www.readbyqxmd.com/read/27902733/single-camera-trap-survey-designs-miss-detections-impacts-on-estimates-of-occupancy-and-community-metrics
#20
Brent S Pease, Clayton K Nielsen, Eric J Holzmueller
The use of camera traps as a tool for studying wildlife populations is commonplace. However, few have considered how the number of detections of wildlife differ depending upon the number of camera traps placed at cameras-sites, and how this impacts estimates of occupancy and community composition. During December 2015-February 2016, we deployed four camera traps per camera-site, separated into treatment groups of one, two, and four camera traps, in southern Illinois to compare whether estimates of wildlife community metrics and occupancy probabilities differed among survey methods...
2016: PloS One
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