Noncentral Chi-Square versus Normal Distributions in Describing the Likelihood Ratio Statistic: The Univariate Case and Its Multivariate Implication

ERIC Educational Resources Information Center

Yuan, Ke-Hai

2008-01-01

In the literature of mean and covariance structure analysis, noncentral chi-square distribution is commonly used to describe the behavior of the likelihood ratio (LR) statistic under alternative hypothesis. Due to the inaccessibility of the rather technical literature for the distribution of the LR statistic, it is widely believed that the…

Using SPSS to Analyze Book Collection Data.

ERIC Educational Resources Information Center

Townley, Charles T.

1981-01-01

Describes and illustrates Statistical Package for the Social Sciences (SPSS) procedures appropriate for book collection data analysis. Several different procedures for univariate, bivariate, and multivariate analysis are discussed, and applications of procedures for book collection studies are presented. Included are 24 tables illustrating output…

Rumen fluid metabolomics analysis associated with feed efficiency on crossbred steers

USDA-ARS?s Scientific Manuscript database

The rumen has a central role in the efficiency of digestion in ruminants. To identify potential differences in rumen function that lead to differences in feed efficiency, rumen fluid metabolomic analysis by LC-MS and multivariate/univariate statistical analysis were used to identify differences in r...

Meta-Analysis in Stata Using Gllamm

ERIC Educational Resources Information Center

Bagos, Pantelis G.

2015-01-01

There are several user-written programs for performing meta-analysis in Stata (Stata Statistical Software: College Station, TX: Stata Corp LP). These include metan, metareg, mvmeta, and glst. However, there are several cases for which these programs do not suffice. For instance, there is no software for performing univariate meta-analysis with…

Univariate and multivariate skewness and kurtosis for measuring nonnormality: Prevalence, influence and estimation.

PubMed

Cain, Meghan K; Zhang, Zhiyong; Yuan, Ke-Hai

2017-10-01

Nonnormality of univariate data has been extensively examined previously (Blanca et al., Methodology: European Journal of Research Methods for the Behavioral and Social Sciences, 9(2), 78-84, 2013; Miceeri, Psychological Bulletin, 105(1), 156, 1989). However, less is known of the potential nonnormality of multivariate data although multivariate analysis is commonly used in psychological and educational research. Using univariate and multivariate skewness and kurtosis as measures of nonnormality, this study examined 1,567 univariate distriubtions and 254 multivariate distributions collected from authors of articles published in Psychological Science and the American Education Research Journal. We found that 74 % of univariate distributions and 68 % multivariate distributions deviated from normal distributions. In a simulation study using typical values of skewness and kurtosis that we collected, we found that the resulting type I error rates were 17 % in a t-test and 30 % in a factor analysis under some conditions. Hence, we argue that it is time to routinely report skewness and kurtosis along with other summary statistics such as means and variances. To facilitate future report of skewness and kurtosis, we provide a tutorial on how to compute univariate and multivariate skewness and kurtosis by SAS, SPSS, R and a newly developed Web application.

Characterization of Interfacial Chemistry of Adhesive/Dentin Bond Using FTIR Chemical Imaging With Univariate and Multivariate Data Processing

PubMed Central

Wang, Yong; Yao, Xiaomei; Parthasarathy, Ranganathan

2008-01-01

Fourier transform infrared (FTIR) chemical imaging can be used to investigate molecular chemical features of the adhesive/dentin interfaces. However, the information is not straightforward, and is not easily extracted. The objective of this study was to use multivariate analysis methods, principal component analysis and fuzzy c-means clustering, to analyze spectral data in comparison with univariate analysis. The spectral imaging data collected from both the adhesive/healthy dentin and adhesive/caries-affected dentin specimens were used and compared. The univariate statistical methods such as mapping of intensities of specific functional group do not always accurately identify functional group locations and concentrations due to more or less band overlapping in adhesive and dentin. Apart from the ease with which information can be extracted, multivariate methods highlight subtle and often important changes in the spectra that are difficult to observe using univariate methods. The results showed that the multivariate methods gave more satisfactory, interpretable results than univariate methods and were conclusive in showing that they can discriminate and classify differences between healthy dentin and caries-affected dentin within the interfacial regions. It is demonstrated that the multivariate FTIR imaging approaches can be used in the rapid characterization of heterogeneous, complex structure. PMID:18980198

Predicting Outcomes After Chemo-Embolization in Patients with Advanced-Stage Hepatocellular Carcinoma: An Evaluation of Different Radiologic Response Criteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunn, Andrew J., E-mail: agunn@uabmc.edu; Sheth, Rahul A.; Luber, Brandon

2017-01-15

PurposeThe purpse of this study was to evaluate the ability of various radiologic response criteria to predict patient outcomes after trans-arterial chemo-embolization with drug-eluting beads (DEB-TACE) in patients with advanced-stage (BCLC C) hepatocellular carcinoma (HCC).Materials and methodsHospital records from 2005 to 2011 were retrospectively reviewed. Non-infiltrative lesions were measured at baseline and on follow-up scans after DEB-TACE according to various common radiologic response criteria, including guidelines of the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver (EASL), and modified RECIST (mRECIST). Statistical analysis was performed to see which,more » if any, of the response criteria could be used as a predictor of overall survival (OS) or time-to-progression (TTP).Results75 patients met inclusion criteria. Median OS and TTP were 22.6 months (95 % CI 11.6–24.8) and 9.8 months (95 % CI 7.1–21.6), respectively. Univariate and multivariate Cox analyses revealed that none of the evaluated criteria had the ability to be used as a predictor for OS or TTP. Analysis of the C index in both univariate and multivariate models showed that the evaluated criteria were not accurate predictors of either OS (C-statistic range: 0.51–0.58 in the univariate model; range: 0.54–0.58 in the multivariate model) or TTP (C-statistic range: 0.55–0.59 in the univariate model; range: 0.57–0.61 in the multivariate model).ConclusionCurrent response criteria are not accurate predictors of OS or TTP in patients with advanced-stage HCC after DEB-TACE.« less

Predicting Outcomes After Chemo-Embolization in Patients with Advanced-Stage Hepatocellular Carcinoma: An Evaluation of Different Radiologic Response Criteria.

PubMed

Gunn, Andrew J; Sheth, Rahul A; Luber, Brandon; Huynh, Minh-Huy; Rachamreddy, Niranjan R; Kalva, Sanjeeva P

2017-01-01

The purpse of this study was to evaluate the ability of various radiologic response criteria to predict patient outcomes after trans-arterial chemo-embolization with drug-eluting beads (DEB-TACE) in patients with advanced-stage (BCLC C) hepatocellular carcinoma (HCC). Hospital records from 2005 to 2011 were retrospectively reviewed. Non-infiltrative lesions were measured at baseline and on follow-up scans after DEB-TACE according to various common radiologic response criteria, including guidelines of the World Health Organization (WHO), Response Evaluation Criteria in Solid Tumors (RECIST), the European Association for the Study of the Liver (EASL), and modified RECIST (mRECIST). Statistical analysis was performed to see which, if any, of the response criteria could be used as a predictor of overall survival (OS) or time-to-progression (TTP). 75 patients met inclusion criteria. Median OS and TTP were 22.6 months (95 % CI 11.6-24.8) and 9.8 months (95 % CI 7.1-21.6), respectively. Univariate and multivariate Cox analyses revealed that none of the evaluated criteria had the ability to be used as a predictor for OS or TTP. Analysis of the C index in both univariate and multivariate models showed that the evaluated criteria were not accurate predictors of either OS (C-statistic range: 0.51-0.58 in the univariate model; range: 0.54-0.58 in the multivariate model) or TTP (C-statistic range: 0.55-0.59 in the univariate model; range: 0.57-0.61 in the multivariate model). Current response criteria are not accurate predictors of OS or TTP in patients with advanced-stage HCC after DEB-TACE.

An Analysis of Methods Used to Examine Gender Differences in Computer-Related Behavior.

ERIC Educational Resources Information Center

Kay, Robin

1992-01-01

Review of research investigating gender differences in computer-related behavior examines statistical and methodological flaws. Issues addressed include sample selection, sample size, scale development, scale quality, the use of univariate and multivariate analyses, regressional analysis, construct definition, construct testing, and the…

Longitudinal Assessment of Self-Reported Recent Back Pain and Combat Deployment in the Millennium Cohort Study

DTIC Science & Technology

2016-11-15

participants who were followed for the development of back pain for an average of 3.9 years. Methods. Descriptive statistics and longitudinal...health, military personnel, occupational health, outcome assessment, statistics, survey methodology . Level of Evidence: 3 Spine 2016;41:1754–1763ack...based on the National Health and Nutrition Examination Survey.21 Statistical Analysis Descriptive and univariate analyses compared character- istics

Borrowing of strength and study weights in multivariate and network meta-analysis.

PubMed

Jackson, Dan; White, Ian R; Price, Malcolm; Copas, John; Riley, Richard D

2017-12-01

Multivariate and network meta-analysis have the potential for the estimated mean of one effect to borrow strength from the data on other effects of interest. The extent of this borrowing of strength is usually assessed informally. We present new mathematical definitions of 'borrowing of strength'. Our main proposal is based on a decomposition of the score statistic, which we show can be interpreted as comparing the precision of estimates from the multivariate and univariate models. Our definition of borrowing of strength therefore emulates the usual informal assessment. We also derive a method for calculating study weights, which we embed into the same framework as our borrowing of strength statistics, so that percentage study weights can accompany the results from multivariate and network meta-analyses as they do in conventional univariate meta-analyses. Our proposals are illustrated using three meta-analyses involving correlated effects for multiple outcomes, multiple risk factor associations and multiple treatments (network meta-analysis).

Borrowing of strength and study weights in multivariate and network meta-analysis

PubMed Central

Jackson, Dan; White, Ian R; Price, Malcolm; Copas, John; Riley, Richard D

2016-01-01

Multivariate and network meta-analysis have the potential for the estimated mean of one effect to borrow strength from the data on other effects of interest. The extent of this borrowing of strength is usually assessed informally. We present new mathematical definitions of ‘borrowing of strength’. Our main proposal is based on a decomposition of the score statistic, which we show can be interpreted as comparing the precision of estimates from the multivariate and univariate models. Our definition of borrowing of strength therefore emulates the usual informal assessment. We also derive a method for calculating study weights, which we embed into the same framework as our borrowing of strength statistics, so that percentage study weights can accompany the results from multivariate and network meta-analyses as they do in conventional univariate meta-analyses. Our proposals are illustrated using three meta-analyses involving correlated effects for multiple outcomes, multiple risk factor associations and multiple treatments (network meta-analysis). PMID:26546254

A Meta-Meta-Analysis: Empirical Review of Statistical Power, Type I Error Rates, Effect Sizes, and Model Selection of Meta-Analyses Published in Psychology

ERIC Educational Resources Information Center

Cafri, Guy; Kromrey, Jeffrey D.; Brannick, Michael T.

2010-01-01

This article uses meta-analyses published in "Psychological Bulletin" from 1995 to 2005 to describe meta-analyses in psychology, including examination of statistical power, Type I errors resulting from multiple comparisons, and model choice. Retrospective power estimates indicated that univariate categorical and continuous moderators, individual…

Estimating an Effect Size in One-Way Multivariate Analysis of Variance (MANOVA)

ERIC Educational Resources Information Center

Steyn, H. S., Jr.; Ellis, S. M.

2009-01-01

When two or more univariate population means are compared, the proportion of variation in the dependent variable accounted for by population group membership is eta-squared. This effect size can be generalized by using multivariate measures of association, based on the multivariate analysis of variance (MANOVA) statistics, to establish whether…

Statistical analysis of Thematic Mapper Simulator data for the geobotanical discrimination of rock types in southwest Oregon

NASA Technical Reports Server (NTRS)

Morrissey, L. A.; Weinstock, K. J.; Mouat, D. A.; Card, D. H.

1984-01-01

An evaluation of Thematic Mapper Simulator (TMS) data for the geobotanical discrimination of rock types based on vegetative cover characteristics is addressed in this research. A methodology for accomplishing this evaluation utilizing univariate and multivariate techniques is presented. TMS data acquired with a Daedalus DEI-1260 multispectral scanner were integrated with vegetation and geologic information for subsequent statistical analyses, which included a chi-square test, an analysis of variance, stepwise discriminant analysis, and Duncan's multiple range test. Results indicate that ultramafic rock types are spectrally separable from nonultramafics based on vegetative cover through the use of statistical analyses.

Individual risk factors for deep infection and compromised fracture healing after intramedullary nailing of tibial shaft fractures: a single centre experience of 480 patients.

PubMed

Metsemakers, W-J; Handojo, K; Reynders, P; Sermon, A; Vanderschot, P; Nijs, S

2015-04-01

Despite modern advances in the treatment of tibial shaft fractures, complications including nonunion, malunion, and infection remain relatively frequent. A better understanding of these injuries and its complications could lead to prevention rather than treatment strategies. A retrospective study was performed to identify risk factors for deep infection and compromised fracture healing after intramedullary nailing (IMN) of tibial shaft fractures. Between January 2000 and January 2012, 480 consecutive patients with 486 tibial shaft fractures were enrolled in the study. Statistical analysis was performed to determine predictors of deep infection and compromised fracture healing. Compromised fracture healing was subdivided in delayed union and nonunion. The following independent variables were selected for analysis: age, sex, smoking, obesity, diabetes, American Society of Anaesthesiologists (ASA) classification, polytrauma, fracture type, open fractures, Gustilo type, primary external fixation (EF), time to nailing (TTN) and reaming. As primary statistical evaluation we performed a univariate analysis, followed by a multiple logistic regression model. Univariate regression analysis revealed similar risk factors for delayed union and nonunion, including fracture type, open fractures and Gustilo type. Factors affecting the occurrence of deep infection in this model were primary EF, a prolonged TTN, open fractures and Gustilo type. Multiple logistic regression analysis revealed polytrauma as the single risk factor for nonunion. With respect to delayed union, no risk factors could be identified. In the same statistical model, deep infection was correlated with primary EF. The purpose of this study was to evaluate risk factors of poor outcome after IMN of tibial shaft fractures. The univariate regression analysis showed that the nature of complications after tibial shaft nailing could be multifactorial. This was not confirmed in a multiple logistic regression model, which only revealed polytrauma and primary EF as risk factors for nonunion and deep infection, respectively. Future strategies should focus on prevention in high-risk populations such as polytrauma patients treated with EF. Copyright © 2014 Elsevier Ltd. All rights reserved.

Statistical methods in personality assessment research.

PubMed

Schinka, J A; LaLone, L; Broeckel, J A

1997-06-01

Emerging models of personality structure and advances in the measurement of personality and psychopathology suggest that research in personality and personality assessment has entered a stage of advanced development, in this article we examine whether researchers in these areas have taken advantage of new and evolving statistical procedures. We conducted a review of articles published in the Journal of Personality, Assessment during the past 5 years. Of the 449 articles that included some form of data analysis, 12.7% used only descriptive statistics, most employed only univariate statistics, and fewer than 10% used multivariate methods of data analysis. We discuss the cost of using limited statistical methods, the possible reasons for the apparent reluctance to employ advanced statistical procedures, and potential solutions to this technical shortcoming.

Moving Beyond Univariate Post-Hoc Testing in Exercise Science: A Primer on Descriptive Discriminate Analysis.

PubMed

Barton, Mitch; Yeatts, Paul E; Henson, Robin K; Martin, Scott B

2016-12-01

There has been a recent call to improve data reporting in kinesiology journals, including the appropriate use of univariate and multivariate analysis techniques. For example, a multivariate analysis of variance (MANOVA) with univariate post hocs and a Bonferroni correction is frequently used to investigate group differences on multiple dependent variables. However, this univariate approach decreases power, increases the risk for Type 1 error, and contradicts the rationale for conducting multivariate tests in the first place. The purpose of this study was to provide a user-friendly primer on conducting descriptive discriminant analysis (DDA), which is a post-hoc strategy to MANOVA that takes into account the complex relationships among multiple dependent variables. A real-world example using the Statistical Package for the Social Sciences syntax and data from 1,095 middle school students on their body composition and body image are provided to explain and interpret the results from DDA. While univariate post hocs increased the risk for Type 1 error to 76%, the DDA identified which dependent variables contributed to group differences and which groups were different from each other. For example, students in the very lean and Healthy Fitness Zone categories for body mass index experienced less pressure to lose weight, more satisfaction with their body, and higher physical self-concept than the Needs Improvement Zone groups. However, perceived pressure to gain weight did not contribute to group differences because it was a suppressor variable. Researchers are encouraged to use DDA when investigating group differences on multiple correlated dependent variables to determine which variables contributed to group differences.

Laryngospasm during emergency department ketamine sedation: a case-control study.

PubMed

Green, Steven M; Roback, Mark G; Krauss, Baruch

2010-11-01

The objective of this study was to assess predictors of emergency department (ED) ketamine-associated laryngospasm using case-control techniques. We performed a matched case-control analysis of a sample of 8282 ED ketamine sedations (including 22 occurrences of laryngospasm) assembled from 32 prior published series. We sequentially studied the association of each of 7 clinical variables with laryngospasm by assigning 4 controls to each case while matching for the remaining 6 variables. We then used univariate statistics and conditional logistic regression to analyze the matched sets. We found no statistical association of age, dose, oropharyngeal procedure, underlying physical illness, route, or coadministered anticholinergics with laryngospasm. Coadministered benzodiazepines showed a borderline association in the multivariate but not univariate analysis that was considered anomalous. This case-control analysis of the largest available sample of ED ketamine-associated laryngospasm did not demonstrate evidence of association with age, dose, or other clinical factors. Such laryngospasm seems to be idiosyncratic, and accordingly, clinicians administering ketamine must be prepared for its rapid identification and management. Given no evidence that they decrease the risk of laryngospasm, coadministered anticholinergics seem unnecessary.

Characterizing multivariate decoding models based on correlated EEG spectral features

PubMed Central

McFarland, Dennis J.

2013-01-01

Objective Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Methods Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). Results The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Conclusions Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. Significance While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. PMID:23466267

Examination of two methods for statistical analysis of data with magnitude and direction emphasizing vestibular research applications

NASA Technical Reports Server (NTRS)

Calkins, D. S.

1998-01-01

When the dependent (or response) variable response variable in an experiment has direction and magnitude, one approach that has been used for statistical analysis involves splitting magnitude and direction and applying univariate statistical techniques to the components. However, such treatment of quantities with direction and magnitude is not justifiable mathematically and can lead to incorrect conclusions about relationships among variables and, as a result, to flawed interpretations. This note discusses a problem with that practice and recommends mathematically correct procedures to be used with dependent variables that have direction and magnitude for 1) computation of mean values, 2) statistical contrasts of and confidence intervals for means, and 3) correlation methods.

Outcome predictors in the management of intramedullary classic ependymoma: An integrative survival analysis.

PubMed

Wang, Yinqing; Cai, Ranze; Wang, Rui; Wang, Chunhua; Chen, Chunmei

2018-06-01

This is a retrospective study.The aim of this study was to illustrate the survival outcomes of patients with classic ependymoma (CE) and identify potential prognostic factors.CE is the most common category of spinal ependymomas, but few published studies have discussed predictors of the survival outcome.A Boolean search of the PubMed, Embase, and OVID databases was conducted by 2 investigators independently. The objects were intramedullary grade II ependymoma according to 2007 WHO classification. Univariate Kaplan-Meier analysis and Log-Rank tests were performed to identify variables associated with progression-free survival (PFS) or overall survival (OS). Multivariate Cox regression was performed to assess hazard ratios (HRs) with 95% confidence intervals (95% CIs). Statistical analysis was performed by SPSS version 23.0 (IBM Corp.) with statistical significance defined as P < .05.A total of 35 studies were identified, including 169 cases of CE. The mean follow-up time across cases was 64.2 ± 51.5 months. Univariate analysis showed that patients who had undergone total resection (TR) had better PFS and OS than those with subtotal resection (STR) and biopsy (P = .002, P = .004, respectively). Within either univariate or multivariate analysis (P = .000, P = .07, respectively), histological type was an independent prognostic factor for PFS of CE [papillary type: HR 0.002, 95% CI (0.000-0.073), P = .001, tanycytic type: HR 0.010, 95% CI (0.000-0.218), P = .003].It was the first integrative analysis of CE to elucidate the correlation between kinds of factors and prognostic outcomes. Definite histological type and safely TR were foundation of CE's management. 4.

On the Choice of Variable for Atmospheric Moisture Analysis

NASA Technical Reports Server (NTRS)

Dee, Dick P.; DaSilva, Arlindo M.; Atlas, Robert (Technical Monitor)

2002-01-01

The implications of using different control variables for the analysis of moisture observations in a global atmospheric data assimilation system are investigated. A moisture analysis based on either mixing ratio or specific humidity is prone to large extrapolation errors, due to the high variability in space and time of these parameters and to the difficulties in modeling their error covariances. Using the logarithm of specific humidity does not alleviate these problems, and has the further disadvantage that very dry background estimates cannot be effectively corrected by observations. Relative humidity is a better choice from a statistical point of view, because this field is spatially and temporally more coherent and error statistics are therefore easier to obtain. If, however, the analysis is designed to preserve relative humidity in the absence of moisture observations, then the analyzed specific humidity field depends entirely on analyzed temperature changes. If the model has a cool bias in the stratosphere this will lead to an unstable accumulation of excess moisture there. A pseudo-relative humidity can be defined by scaling the mixing ratio by the background saturation mixing ratio. A univariate pseudo-relative humidity analysis will preserve the specific humidity field in the absence of moisture observations. A pseudorelative humidity analysis is shown to be equivalent to a mixing ratio analysis with flow-dependent covariances. In the presence of multivariate (temperature-moisture) observations it produces analyzed relative humidity values that are nearly identical to those produced by a relative humidity analysis. Based on a time series analysis of radiosonde observed-minus-background differences it appears to be more justifiable to neglect specific humidity-temperature correlations (in a univariate pseudo-relative humidity analysis) than to neglect relative humidity-temperature correlations (in a univariate relative humidity analysis). A pseudo-relative humidity analysis is easily implemented in an existing moisture analysis system, by simply scaling observed-minus background moisture residuals prior to solving the analysis equation, and rescaling the analyzed increments afterward.

Multivariate meta-analysis: potential and promise.

PubMed

Jackson, Dan; Riley, Richard; White, Ian R

2011-09-10

The multivariate random effects model is a generalization of the standard univariate model. Multivariate meta-analysis is becoming more commonly used and the techniques and related computer software, although continually under development, are now in place. In order to raise awareness of the multivariate methods, and discuss their advantages and disadvantages, we organized a one day 'Multivariate meta-analysis' event at the Royal Statistical Society. In addition to disseminating the most recent developments, we also received an abundance of comments, concerns, insights, critiques and encouragement. This article provides a balanced account of the day's discourse. By giving others the opportunity to respond to our assessment, we hope to ensure that the various view points and opinions are aired before multivariate meta-analysis simply becomes another widely used de facto method without any proper consideration of it by the medical statistics community. We describe the areas of application that multivariate meta-analysis has found, the methods available, the difficulties typically encountered and the arguments for and against the multivariate methods, using four representative but contrasting examples. We conclude that the multivariate methods can be useful, and in particular can provide estimates with better statistical properties, but also that these benefits come at the price of making more assumptions which do not result in better inference in every case. Although there is evidence that multivariate meta-analysis has considerable potential, it must be even more carefully applied than its univariate counterpart in practice. Copyright © 2011 John Wiley & Sons, Ltd.

Differentiation of benign and malignant ampullary obstruction by multi-row detector CT.

PubMed

Angthong, Wirana; Jiarakoop, Kran; Tangtiang, Kaan

2018-05-21

To determine useful CT parameters to differentiate ampullary carcinomas from benign ampullary obstruction. This study included 93 patients who underwent abdominal CT, 31 patients with ampullary carcinomas, and 62 patients with benign ampullary obstruction. Two radiologists independently evaluated CT parameters then reached consensus decisions. Statistically significant CT parameters were identified through univariate and multivariate analyses. In univariate analysis, the presence of ampullary mass, asymmetric, abrupt narrowing of distal common bile duct (CBD), dilated intrahepatic bile duct (IHD), dilated pancreatic duct (PD), peripancreatic lymphadenopathy, duodenal wall thickening, and delayed enhancement were more frequently in ampullary carcinomas observed (P < 0.05). Multivariate logistic regression analysis using significant CT parameters and clinical data from univariate analysis, and clinical symptom with jaundice (P = 0.005) was an independent predictor of ampullary carcinomas. For multivariate analysis using only significant CT parameters, abrupt narrowing of distal CBD was an independent predictor of ampullary carcinomas (P = 0.019). Among various CT criteria, abrupt narrowing of distal CBD and dilated IHD had highest sensitivity (77.4%) and highest accuracy (90.3%). The abrupt narrowing of distal CBD and dilated IHD is useful for differentiation of ampullary carcinomas from benign entity in patients without the presence of mass.

Robustness of Multiple Objective Decision Analysis Preference Functions

DTIC Science & Technology

2002-06-01

p p′ : The probability of some event. ,i ip q : The probability of event . i Π : An aggregation of proportional data used in calculating a test ...statistical tests of the significance of the term and also is conducted in a multivariate framework rather than the ROSA univariate approach. A...residual error is ˆ−e = y y (45) The coefficient provides a ready indicator of the contribution for the associated variable and statistical tests

Multivariate meta-analysis: Potential and promise

PubMed Central

Jackson, Dan; Riley, Richard; White, Ian R

2011-01-01

The multivariate random effects model is a generalization of the standard univariate model. Multivariate meta-analysis is becoming more commonly used and the techniques and related computer software, although continually under development, are now in place. In order to raise awareness of the multivariate methods, and discuss their advantages and disadvantages, we organized a one day ‘Multivariate meta-analysis’ event at the Royal Statistical Society. In addition to disseminating the most recent developments, we also received an abundance of comments, concerns, insights, critiques and encouragement. This article provides a balanced account of the day's discourse. By giving others the opportunity to respond to our assessment, we hope to ensure that the various view points and opinions are aired before multivariate meta-analysis simply becomes another widely used de facto method without any proper consideration of it by the medical statistics community. We describe the areas of application that multivariate meta-analysis has found, the methods available, the difficulties typically encountered and the arguments for and against the multivariate methods, using four representative but contrasting examples. We conclude that the multivariate methods can be useful, and in particular can provide estimates with better statistical properties, but also that these benefits come at the price of making more assumptions which do not result in better inference in every case. Although there is evidence that multivariate meta-analysis has considerable potential, it must be even more carefully applied than its univariate counterpart in practice. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21268052

PyMVPA: A python toolbox for multivariate pattern analysis of fMRI data.

PubMed

Hanke, Michael; Halchenko, Yaroslav O; Sederberg, Per B; Hanson, Stephen José; Haxby, James V; Pollmann, Stefan

2009-01-01

Decoding patterns of neural activity onto cognitive states is one of the central goals of functional brain imaging. Standard univariate fMRI analysis methods, which correlate cognitive and perceptual function with the blood oxygenation-level dependent (BOLD) signal, have proven successful in identifying anatomical regions based on signal increases during cognitive and perceptual tasks. Recently, researchers have begun to explore new multivariate techniques that have proven to be more flexible, more reliable, and more sensitive than standard univariate analysis. Drawing on the field of statistical learning theory, these new classifier-based analysis techniques possess explanatory power that could provide new insights into the functional properties of the brain. However, unlike the wealth of software packages for univariate analyses, there are few packages that facilitate multivariate pattern classification analyses of fMRI data. Here we introduce a Python-based, cross-platform, and open-source software toolbox, called PyMVPA, for the application of classifier-based analysis techniques to fMRI datasets. PyMVPA makes use of Python's ability to access libraries written in a large variety of programming languages and computing environments to interface with the wealth of existing machine learning packages. We present the framework in this paper and provide illustrative examples on its usage, features, and programmability.

PyMVPA: A Python toolbox for multivariate pattern analysis of fMRI data

PubMed Central

Hanke, Michael; Halchenko, Yaroslav O.; Sederberg, Per B.; Hanson, Stephen José; Haxby, James V.; Pollmann, Stefan

2009-01-01

Decoding patterns of neural activity onto cognitive states is one of the central goals of functional brain imaging. Standard univariate fMRI analysis methods, which correlate cognitive and perceptual function with the blood oxygenation-level dependent (BOLD) signal, have proven successful in identifying anatomical regions based on signal increases during cognitive and perceptual tasks. Recently, researchers have begun to explore new multivariate techniques that have proven to be more flexible, more reliable, and more sensitive than standard univariate analysis. Drawing on the field of statistical learning theory, these new classifier-based analysis techniques possess explanatory power that could provide new insights into the functional properties of the brain. However, unlike the wealth of software packages for univariate analyses, there are few packages that facilitate multivariate pattern classification analyses of fMRI data. Here we introduce a Python-based, cross-platform, and open-source software toolbox, called PyMVPA, for the application of classifier-based analysis techniques to fMRI datasets. PyMVPA makes use of Python's ability to access libraries written in a large variety of programming languages and computing environments to interface with the wealth of existing machine-learning packages. We present the framework in this paper and provide illustrative examples on its usage, features, and programmability. PMID:19184561

Characterizing multivariate decoding models based on correlated EEG spectral features.

PubMed

McFarland, Dennis J

2013-07-01

Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Visual classification of very fine-grained sediments: Evaluation through univariate and multivariate statistics

USGS Publications Warehouse

Hohn, M. Ed; Nuhfer, E.B.; Vinopal, R.J.; Klanderman, D.S.

1980-01-01

Classifying very fine-grained rocks through fabric elements provides information about depositional environments, but is subject to the biases of visual taxonomy. To evaluate the statistical significance of an empirical classification of very fine-grained rocks, samples from Devonian shales in four cored wells in West Virginia and Virginia were measured for 15 variables: quartz, illite, pyrite and expandable clays determined by X-ray diffraction; total sulfur, organic content, inorganic carbon, matrix density, bulk density, porosity, silt, as well as density, sonic travel time, resistivity, and ??-ray response measured from well logs. The four lithologic types comprised: (1) sharply banded shale, (2) thinly laminated shale, (3) lenticularly laminated shale, and (4) nonbanded shale. Univariate and multivariate analyses of variance showed that the lithologic classification reflects significant differences for the variables measured, difference that can be detected independently of stratigraphic effects. Little-known statistical methods found useful in this work included: the multivariate analysis of variance with more than one effect, simultaneous plotting of samples and variables on canonical variates, and the use of parametric ANOVA and MANOVA on ranked data. ?? 1980 Plenum Publishing Corporation.

Relationship between climatic variables and the variation in bulk tank milk composition using canonical correlation analysis.

PubMed

Stürmer, Morgana; Busanello, Marcos; Velho, João Pedro; Heck, Vanessa Isabel; Haygert-Velho, Ione Maria Pereira

2018-06-04

A number of studies have addressed the relations between climatic variables and milk composition, but these works used univariate statistical approaches. In our study, we used a multivariate approach (canonical correlation) to study the impact of climatic variables on milk composition, price, and monthly milk production at a dairy farm using bulk tank milk data. Data on milk composition, price, and monthly milk production were obtained from a dairy company that purchased the milk from the farm, while climatic variable data were obtained from the National Institute of Meteorology (INMET). The data are from January 2014 to December 2016. Univariate correlation analysis and canonical correlation analysis were performed. Few correlations between the climatic variables and milk composition were found using a univariate approach. However, using canonical correlation analysis, we found a strong and significant correlation (r c  = 0.95, p value = 0.0029). Lactose, ambient temperature measures (mean, minimum, and maximum), and temperature-humidity index (THI) were found to be the most important variables for the canonical correlation. Our study indicated that 10.2% of the variation in milk composition, pricing, and monthly milk production can be explained by climatic variables. Ambient temperature variables, together with THI, seem to have the most influence on variation in milk composition.

Relationship between climatic variables and the variation in bulk tank milk composition using canonical correlation analysis

NASA Astrophysics Data System (ADS)

Stürmer, Morgana; Busanello, Marcos; Velho, João Pedro; Heck, Vanessa Isabel; Haygert-Velho, Ione Maria Pereira

2018-06-01

A number of studies have addressed the relations between climatic variables and milk composition, but these works used univariate statistical approaches. In our study, we used a multivariate approach (canonical correlation) to study the impact of climatic variables on milk composition, price, and monthly milk production at a dairy farm using bulk tank milk data. Data on milk composition, price, and monthly milk production were obtained from a dairy company that purchased the milk from the farm, while climatic variable data were obtained from the National Institute of Meteorology (INMET). The data are from January 2014 to December 2016. Univariate correlation analysis and canonical correlation analysis were performed. Few correlations between the climatic variables and milk composition were found using a univariate approach. However, using canonical correlation analysis, we found a strong and significant correlation (r c = 0.95, p value = 0.0029). Lactose, ambient temperature measures (mean, minimum, and maximum), and temperature-humidity index (THI) were found to be the most important variables for the canonical correlation. Our study indicated that 10.2% of the variation in milk composition, pricing, and monthly milk production can be explained by climatic variables. Ambient temperature variables, together with THI, seem to have the most influence on variation in milk composition.

GLIMMPSE Lite: Calculating Power and Sample Size on Smartphone Devices

PubMed Central

Munjal, Aarti; Sakhadeo, Uttara R.; Muller, Keith E.; Glueck, Deborah H.; Kreidler, Sarah M.

2014-01-01

Researchers seeking to develop complex statistical applications for mobile devices face a common set of difficult implementation issues. In this work, we discuss general solutions to the design challenges. We demonstrate the utility of the solutions for a free mobile application designed to provide power and sample size calculations for univariate, one-way analysis of variance (ANOVA), GLIMMPSE Lite. Our design decisions provide a guide for other scientists seeking to produce statistical software for mobile platforms. PMID:25541688

Bivariate Rainfall and Runoff Analysis Using Shannon Entropy Theory

NASA Astrophysics Data System (ADS)

Rahimi, A.; Zhang, L.

2012-12-01

Rainfall-Runoff analysis is the key component for many hydrological and hydraulic designs in which the dependence of rainfall and runoff needs to be studied. It is known that the convenient bivariate distribution are often unable to model the rainfall-runoff variables due to that they either have constraints on the range of the dependence or fixed form for the marginal distributions. Thus, this paper presents an approach to derive the entropy-based joint rainfall-runoff distribution using Shannon entropy theory. The distribution derived can model the full range of dependence and allow different specified marginals. The modeling and estimation can be proceeded as: (i) univariate analysis of marginal distributions which includes two steps, (a) using the nonparametric statistics approach to detect modes and underlying probability density, and (b) fitting the appropriate parametric probability density functions; (ii) define the constraints based on the univariate analysis and the dependence structure; (iii) derive and validate the entropy-based joint distribution. As to validate the method, the rainfall-runoff data are collected from the small agricultural experimental watersheds located in semi-arid region near Riesel (Waco), Texas, maintained by the USDA. The results of unviariate analysis show that the rainfall variables follow the gamma distribution, whereas the runoff variables have mixed structure and follow the mixed-gamma distribution. With this information, the entropy-based joint distribution is derived using the first moments, the first moments of logarithm transformed rainfall and runoff, and the covariance between rainfall and runoff. The results of entropy-based joint distribution indicate: (1) the joint distribution derived successfully preserves the dependence between rainfall and runoff, and (2) the K-S goodness of fit statistical tests confirm the marginal distributions re-derived reveal the underlying univariate probability densities which further assure that the entropy-based joint rainfall-runoff distribution are satisfactorily derived. Overall, the study shows the Shannon entropy theory can be satisfactorily applied to model the dependence between rainfall and runoff. The study also shows that the entropy-based joint distribution is an appropriate approach to capture the dependence structure that cannot be captured by the convenient bivariate joint distributions. Joint Rainfall-Runoff Entropy Based PDF, and Corresponding Marginal PDF and Histogram for W12 Watershed The K-S Test Result and RMSE on Univariate Distributions Derived from the Maximum Entropy Based Joint Probability Distribution;

One Hundred Ways to be Non-Fickian - A Rigorous Multi-Variate Statistical Analysis of Pore-Scale Transport

NASA Astrophysics Data System (ADS)

Most, Sebastian; Nowak, Wolfgang; Bijeljic, Branko

2015-04-01

Fickian transport in groundwater flow is the exception rather than the rule. Transport in porous media is frequently simulated via particle methods (i.e. particle tracking random walk (PTRW) or continuous time random walk (CTRW)). These methods formulate transport as a stochastic process of particle position increments. At the pore scale, geometry and micro-heterogeneities prohibit the commonly made assumption of independent and normally distributed increments to represent dispersion. Many recent particle methods seek to loosen this assumption. Hence, it is important to get a better understanding of the processes at pore scale. For our analysis we track the positions of 10.000 particles migrating through the pore space over time. The data we use come from micro CT scans of a homogeneous sandstone and encompass about 10 grain sizes. Based on those images we discretize the pore structure and simulate flow at the pore scale based on the Navier-Stokes equation. This flow field realistically describes flow inside the pore space and we do not need to add artificial dispersion during the transport simulation. Next, we use particle tracking random walk and simulate pore-scale transport. Finally, we use the obtained particle trajectories to do a multivariate statistical analysis of the particle motion at the pore scale. Our analysis is based on copulas. Every multivariate joint distribution is a combination of its univariate marginal distributions. The copula represents the dependence structure of those univariate marginals and is therefore useful to observe correlation and non-Gaussian interactions (i.e. non-Fickian transport). The first goal of this analysis is to better understand the validity regions of commonly made assumptions. We are investigating three different transport distances: 1) The distance where the statistical dependence between particle increments can be modelled as an order-one Markov process. This would be the Markovian distance for the process, where the validity of yet-unexplored non-Gaussian-but-Markovian random walks start. 2) The distance where bivariate statistical dependence simplifies to a multi-Gaussian dependence based on simple linear correlation (validity of correlated PTRW/CTRW). 3) The distance of complete statistical independence (validity of classical PTRW/CTRW). The second objective is to reveal characteristic dependencies influencing transport the most. Those dependencies can be very complex. Copulas are highly capable of representing linear dependence as well as non-linear dependence. With that tool we are able to detect persistent characteristics dominating transport even across different scales. The results derived from our experimental data set suggest that there are many more non-Fickian aspects of pore-scale transport than the univariate statistics of longitudinal displacements. Non-Fickianity can also be found in transverse displacements, and in the relations between increments at different time steps. Also, the found dependence is non-linear (i.e. beyond simple correlation) and persists over long distances. Thus, our results strongly support the further refinement of techniques like correlated PTRW or correlated CTRW towards non-linear statistical relations.

Comparison of 20% sulfur hexafluoride with air for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK).

PubMed

Botsford, Benjamin; Vedana, Gustavo; Cope, Leslie; Yiu, Samuel C; Jun, Albert S

2016-01-01

To compare the effect of 20% sulfur hexafluoride (SF6) with that of air on graft detachment rates for intraocular tamponade in Descemet membrane endothelial keratoplasty (DMEK). Forty-two eyes of patients who underwent DMEK by a single surgeon (A.S.J.) at Wilmer Eye Institute between January 2012 and 2014 were identified; 21 received air for intraocular tamponade and the next consecutive 21 received SF6. The main outcome measure was the graft detachment rate; univariate and multivariate analyses were performed. The graft detachment rate was 67% in the air group and 19% in the SF6 group (p<0.05). No complete graft detachments occurred, and all partial detachments underwent intervention with injection of intraocular air. The percentages of eyes with 20/25 or better vision were not different between the groups (67% vs. 71%). Univariate analysis showed significantly higher detachment rates with air tamponade (OR, 8.50; p<0.005) and larger donor graft size (OR, 14.96; p<0.05). Multivariate analysis with gas but not graft size included showed that gas was an independent statistically significant predictor of outcome (OR, 6.65; p<0.05). When graft size was included as a covariate, gas was no longer a statistically significant predictor of detachment but maintained OR of 7.81 (p=0.063) similar to the results of univariate and multivariate analyses without graft size. In comparison with air, graft detachment rates for intraocular tamponade in DMEK were significantly reduced by 20% SF6.

Univariate Probability Distributions

ERIC Educational Resources Information Center

Leemis, Lawrence M.; Luckett, Daniel J.; Powell, Austin G.; Vermeer, Peter E.

2012-01-01

We describe a web-based interactive graphic that can be used as a resource in introductory classes in mathematical statistics. This interactive graphic presents 76 common univariate distributions and gives details on (a) various features of the distribution such as the functional form of the probability density function and cumulative distribution…

A Matlab user interface for the statistically assisted fluid registration algorithm and tensor-based morphometry

NASA Astrophysics Data System (ADS)

Yepes-Calderon, Fernando; Brun, Caroline; Sant, Nishita; Thompson, Paul; Lepore, Natasha

2015-01-01

Tensor-Based Morphometry (TBM) is an increasingly popular method for group analysis of brain MRI data. The main steps in the analysis consist of a nonlinear registration to align each individual scan to a common space, and a subsequent statistical analysis to determine morphometric differences, or difference in fiber structure between groups. Recently, we implemented the Statistically-Assisted Fluid Registration Algorithm or SAFIRA,1 which is designed for tracking morphometric differences among populations. To this end, SAFIRA allows the inclusion of statistical priors extracted from the populations being studied as regularizers in the registration. This flexibility and degree of sophistication limit the tool to expert use, even more so considering that SAFIRA was initially implemented in command line mode. Here, we introduce a new, intuitive, easy to use, Matlab-based graphical user interface for SAFIRA's multivariate TBM. The interface also generates different choices for the TBM statistics, including both the traditional univariate statistics on the Jacobian matrix, and comparison of the full deformation tensors.2 This software will be freely disseminated to the neuroimaging research community.

Pressure ulcer incidence and Braden subscales: Retrospective cohort analysis in general wards of a Portuguese hospital.

PubMed

Sardo, Pedro Miguel Garcez; Guedes, Jenifer Adriana Domingues; Alvarelhão, José Joaquim Marques; Machado, Paulo Alexandre Puga; Melo, Elsa Maria Oliveira Pinheiro

2018-05-01

To study the influence of Braden subscales scores (at the first pressure ulcer risk assessment) on pressure ulcer incidence using a univariate and a multivariate time to event analysis. Retrospective cohort analysis of electronic health record database from adult patients admitted without pressure ulcer(s) to medical and surgical wards of a Portuguese hospital during 2012. The hazard ratio of developing a pressure ulcer during the length of inpatient stay was calculated by univariate Cox regression for each variable of interest and by multivariate Cox regression for the Braden subscales that were statistically significant. This study included a sample of 6552 participants. During the length of stay, 153 participants developed (at least) one pressure ulcer, giving a pressure ulcer incidence of 2.3%. The univariate time to event analysis showed that all Braden subscales, except "nutrition", were associated with the development of pressure ulcer. By multivariate analysis the scores for "mobility" and "activity" were independently predictive of the development of pressure ulcer(s) for all participants. (Im)"mobility" (the lack of ability to change and control body position) and (in)"activity" (the limited degree of physical activity) were the major risk factors assessed by Braden Scale for pressure ulcer development during the length of inpatient stay. Thus, the greatest efforts in managing pressure ulcer risk should be on "mobility" and "activity", independently of the total Braden Scale score. Copyright © 2018 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

Risk Factors for Failure of Male Slings and Artificial Urinary Sphincters: Results from a Large Middle European Cohort Study.

PubMed

Hüsch, Tanja; Kretschmer, Alexander; Thomsen, Frauke; Kronlachner, Dominik; Kurosch, Martin; Obaje, Alice; Anding, Ralf; Pottek, Tobias; Rose, Achim; Olianas, Roberto; Friedl, Alexander; Hübner, Wilhelm; Homberg, Roland; Pfitzenmaier, Jesco; Grein, Ulrich; Queissert, Fabian; Naumann, Carsten Maik; Schweiger, Josef; Wotzka, Carola; Nyarangi-Dix, Joanne; Hofmann, Torben; Ulm, Kurt; Bauer, Ricarda M; Haferkamp, Axel

2017-01-01

We analysed the impact of predefined risk factors: age, diabetes, history of pelvic irradiation, prior surgery for stress urinary incontinence (SUI), prior urethral stricture, additional procedure during SUI surgery, duration of incontinence, ASA-classification and cause for incontinence on failure and complications in male SUI surgery. We retrospectively identified 506 patients with an artificial urinary sphincter (AUS) and 513 patients with a male sling (MS) in a multicenter cohort study. Complication rates were correlated to the risk factors in univariate analysis. Subsequently, a multivariate logistic regression adjusted to the risk factors was performed. A p value <0.05 was considered statistically significant. A history of pelvic irradiation was an independent risk factor for explantation in AUS (p < 0.001) and MS (p = 0.018). Moreover, prior urethral stricture (p = 0.036) and higher ASA-classification (p = 0.039) were positively correlated with explantation in univariate analysis for AUS. Urethral erosion was correlated with prior urethral stricture (p < 0.001) and a history of pelvic irradiation (p < 0.001) in AUS. Furthermore, infection was correlated with additional procedures during SUI surgery in univariate analysis (p = 0.037) in MS. We first identified the correlation of higher ASA-classification and explantation in AUS. Nevertheless, only a few novel risk factors had a significant influence on the failure of MS or AUS. © 2016 S. Karger AG, Basel.

Assessment of vocal fold mobility before and after cardiothoracic surgery in children.

PubMed

Carpes, Luthiana F; Kozak, Frederick K; Leblanc, Jacques G; Campbell, Andrew I; Human, Derek G; Fandino, Marcela; Ludemann, Jeffrey P; Moxham, J Paul; Fiori, Humberto

2011-06-01

To assess the incidence of vocal fold immobility (VFI) after cardiothoracic surgery in children and to determine the factors potentially associated with this outcome. Flexible laryngoscopy to assess vocal fold mobility was performed before surgery and within 72 hours after extubation in 100 pediatric patients who underwent cardiothoracic procedures. The 2 operating surgeons recorded the surgical technique and their impression of possible injury to the recurrent laryngeal nerve. The presence of laryngeal symptoms, such as stridor, hoarseness, and strength of cry, after extubation was documented. Of 100 children included in this study, 8 had VFI after surgery. Univariate analyses showed that these 8 patients were younger and weighed less than the patients with normal vocal fold movement. Monopolar cautery was used in all patients with VFI. On univariate analysis, factors statistically significantly associated with VFI were circulatory arrest and dissection or ligation of the patent ductus arteriosus, left pulmonary artery, right pulmonary artery, or descending aorta. However, multivariate analyses failed to show these associations. The incidence of VFI after cardiothoracic surgery in our population of children was 8.0% (8 of 100). Of several factors found to be potentially associated with VFI on univariate analysis, none were significant on multivariate analysis. This may be a result of the few patients with VFI. A larger multicenter prospective study would be needed to definitively identify factors associated with the outcome of VFI.

When Does Neoadjuvant Chemotherapy Really Avoid Radiotherapy? Clinical Predictors of Adjuvant Radiotherapy in Cervical Cancer.

PubMed

Papadia, Andrea; Bellati, Filippo; Bogani, Giorgio; Ditto, Antonino; Martinelli, Fabio; Lorusso, Domenica; Donfrancesco, Cristina; Gasparri, Maria Luisa; Raspagliesi, Francesco

2015-12-01

The aim of this study was to identify clinical variables that may predict the need for adjuvant radiotherapy after neoadjuvant chemotherapy (NACT) and radical surgery in locally advanced cervical cancer patients. A retrospective series of cervical cancer patients with International Federation of Gynecology and Obstetrics (FIGO) stages IB2-IIB treated with NACT followed by radical surgery was analyzed. Clinical predictors of persistence of intermediate- and/or high-risk factors at final pathological analysis were investigated. Statistical analysis was performed using univariate and multivariate analysis and using a model based on artificial intelligence known as artificial neuronal network (ANN) analysis. Overall, 101 patients were available for the analyses. Fifty-two (51 %) patients were considered at high risk secondary to parametrial, resection margin and/or lymph node involvement. When disease was confined to the cervix, four (4 %) patients were considered at intermediate risk. At univariate analysis, FIGO grade 3, stage IIB disease at diagnosis and the presence of enlarged nodes before NACT predicted the presence of intermediate- and/or high-risk factors at final pathological analysis. At multivariate analysis, only FIGO grade 3 and tumor diameter maintained statistical significance. The specificity of ANN models in evaluating predictive variables was slightly superior to conventional multivariable models. FIGO grade, stage, tumor diameter, and histology are associated with persistence of pathological intermediate- and/or high-risk factors after NACT and radical surgery. This information is useful in counseling patients at the time of treatment planning with regard to the probability of being subjected to pelvic radiotherapy after completion of the initially planned treatment.

Teaching Univariate Measures of Location-Using Loss Functions

ERIC Educational Resources Information Center

Paolino, Jon-Paul

2018-01-01

This article presents a new method for introductory teaching of the sample mean, median and mode(s) from a univariate dataset. These basic statistical concepts are taught at various levels of education from elementary school curriculums to courses at the tertiary level. These descriptive measures of location can be taught as optimized solutions to…

Chemical Contaminant and Decontaminant Test Methodology Source Document. Second Edition

DTIC Science & Technology

2012-07-01

performance as described in “A Statistical Overview on Univariate Calibration, Inverse Regression, and Detection Limits: Application to Gas Chromatography...Overview on Univariate Calibration, Inverse Regression, and Detection Limits: Application to Gas Chromatography/Mass Spectrometry Technique. Mass... APPLICATIONS INTERNATIONAL CORPORATION Gunpowder, MD 21010-0068 July 2012 Approved for public release; distribution is unlimited

Forecasting electric vehicles sales with univariate and multivariate time series models: The case of China.

PubMed

Zhang, Yong; Zhong, Miner; Geng, Nana; Jiang, Yunjian

2017-01-01

The market demand for electric vehicles (EVs) has increased in recent years. Suitable models are necessary to understand and forecast EV sales. This study presents a singular spectrum analysis (SSA) as a univariate time-series model and vector autoregressive model (VAR) as a multivariate model. Empirical results suggest that SSA satisfactorily indicates the evolving trend and provides reasonable results. The VAR model, which comprised exogenous parameters related to the market on a monthly basis, can significantly improve the prediction accuracy. The EV sales in China, which are categorized into battery and plug-in EVs, are predicted in both short term (up to December 2017) and long term (up to 2020), as statistical proofs of the growth of the Chinese EV industry.

Forecasting electric vehicles sales with univariate and multivariate time series models: The case of China

PubMed Central

Zhang, Yong; Zhong, Miner; Geng, Nana; Jiang, Yunjian

2017-01-01

The market demand for electric vehicles (EVs) has increased in recent years. Suitable models are necessary to understand and forecast EV sales. This study presents a singular spectrum analysis (SSA) as a univariate time-series model and vector autoregressive model (VAR) as a multivariate model. Empirical results suggest that SSA satisfactorily indicates the evolving trend and provides reasonable results. The VAR model, which comprised exogenous parameters related to the market on a monthly basis, can significantly improve the prediction accuracy. The EV sales in China, which are categorized into battery and plug-in EVs, are predicted in both short term (up to December 2017) and long term (up to 2020), as statistical proofs of the growth of the Chinese EV industry. PMID:28459872

Statistical comparison of pooled nitrogen washout data of various altitude decompression response groups

NASA Technical Reports Server (NTRS)

Edwards, B. F.; Waligora, J. M.; Horrigan, D. J., Jr.

1985-01-01

This analysis was done to determine whether various decompression response groups could be characterized by the pooled nitrogen (N2) washout profiles of the group members, pooling individual washout profiles provided a smooth time dependent function of means representative of the decompression response group. No statistically significant differences were detected. The statistical comparisons of the profiles were performed by means of univariate weighted t-test at each 5 minute profile point, and with levels of significance of 5 and 10 percent. The estimated powers of the tests (i.e., probabilities) to detect the observed differences in the pooled profiles were of the order of 8 to 30 percent.

Factors predictive of the onset and duration of action of local anesthesia in mandibular third-molar surgery: a prospective study.

PubMed

Al-Shayyab, Mohammad H; Baqain, Zaid H

2018-04-01

The aim of this study was to assess the influence of patients' and surgical variables on the onset and duration of action of local anesthesia (LA) in mandibular third-molar (M3) surgery. Patients scheduled for mandibular M3 surgery were considered for inclusion in this prospective cohort study. Patients' and surgical variables were recorded. Two per cent (2%) lidocaine with 1:100,000 epinephrine was used to block the nerves for extraction of mandibular M3. Then, the onset of action and duration of LA were monitored. Univariate analysis and multivariate regression analysis were used to analyze the data. The final cohort included 88 subjects (32 men and 56 women; mean age ± SD = 29.3 ± 12.3 yr). With univariate analysis, age, gender, body mass index (BMI), smoking quantity and duration, operation time, and 'volume of local anesthetic needed' significantly influenced the onset of action and duration of LA. Multivariate regression revealed that age and smoking quantity were the only statistically significant predictors of the onset of action of LA, whereas age, smoking quantity, and 'volume of local anesthetic needed' were the only statistically significant predictors of duration of LA. Further studies are recommended to uncover other predictors of the onset of action and duration of LA. © 2018 Eur J Oral Sci.

Quick Overview Scout 2008 Version 1.0

EPA Science Inventory

The Scout 2008 version 1.0 statistical software package has been updated from past DOS and Windows versions to provide classical and robust univariate and multivariate graphical and statistical methods that are not typically available in commercial or freeware statistical softwar...

[Retrospective statistical analysis of clinical factors of recurrence in chronic subdural hematoma: correlation between univariate and multivariate analysis].

PubMed

Takayama, Motoharu; Terui, Keita; Oiwa, Yoshitsugu

2012-10-01

Chronic subdural hematoma is common in elderly individuals and surgical procedures are simple. The recurrence rate of chronic subdural hematoma, however, varies from 9.2 to 26.5% after surgery. The authors studied factors of the recurrence using univariate and multivariate analyses in patients with chronic subdural hematoma We retrospectively reviewed 239 consecutive cases of chronic subdural hematoma who received burr-hole surgery with irrigation and closed-system drainage. We analyzed the relationships between recurrence of chronic subdural hematoma and factors such as sex, age, laterality, bleeding tendency, other complicated diseases, density on CT, volume of the hematoma, residual air in the hematoma cavity, use of artificial cerebrospinal fluid. Twenty-one patients (8.8%) experienced a recurrence of chronic subdural hematoma. Multiple logistic regression found that the recurrence rate was higher in patients with a large volume of the residual air, and was lower in patients using artificial cerebrospinal fluid. No statistical differences were found in bleeding tendency. Techniques to reduce the air in the hematoma cavity are important for good outcome in surgery of chronic subdural hematoma. Also, the use of artificial cerebrospinal fluid reduces recurrence of chronic subdural hematoma. The surgical procedures can be the same for patients with bleeding tendencies.

Weighing of risk factors for penetrating keratoplasty graft failure: application of Risk Score System.

PubMed

Tourkmani, Abdo Karim; Sánchez-Huerta, Valeria; De Wit, Guillermo; Martínez, Jaime D; Mingo, David; Mahillo-Fernández, Ignacio; Jiménez-Alfaro, Ignacio

2017-01-01

To analyze the relationship between the score obtained in the Risk Score System (RSS) proposed by Hicks et al with penetrating keratoplasty (PKP) graft failure at 1y postoperatively and among each factor in the RSS with the risk of PKP graft failure using univariate and multivariate analysis. The retrospective cohort study had 152 PKPs from 152 patients. Eighteen cases were excluded from our study due to primary failure (10 cases), incomplete medical notes (5 cases) and follow-up less than 1y (3 cases). We included 134 PKPs from 134 patients stratified by preoperative risk score. Spearman coefficient was calculated for the relationship between the score obtained and risk of failure at 1y. Univariate and multivariate analysis were calculated for the impact of every single risk factor included in the RSS over graft failure at 1y. Spearman coefficient showed statistically significant correlation between the score in the RSS and graft failure ( P <0.05). Multivariate logistic regression analysis showed no statistically significant relationship ( P >0.05) between diagnosis and lens status with graft failure. The relationship between the other risk factors studied and graft failure was significant ( P <0.05), although the results for previous grafts and graft failure was unreliable. None of our patients had previous blood transfusion, thus, it had no impact. After the application of multivariate analysis techniques, some risk factors do not show the expected impact over graft failure at 1y.

Weighing of risk factors for penetrating keratoplasty graft failure: application of Risk Score System

PubMed Central

Tourkmani, Abdo Karim; Sánchez-Huerta, Valeria; De Wit, Guillermo; Martínez, Jaime D.; Mingo, David; Mahillo-Fernández, Ignacio; Jiménez-Alfaro, Ignacio

2017-01-01

AIM To analyze the relationship between the score obtained in the Risk Score System (RSS) proposed by Hicks et al with penetrating keratoplasty (PKP) graft failure at 1y postoperatively and among each factor in the RSS with the risk of PKP graft failure using univariate and multivariate analysis. METHODS The retrospective cohort study had 152 PKPs from 152 patients. Eighteen cases were excluded from our study due to primary failure (10 cases), incomplete medical notes (5 cases) and follow-up less than 1y (3 cases). We included 134 PKPs from 134 patients stratified by preoperative risk score. Spearman coefficient was calculated for the relationship between the score obtained and risk of failure at 1y. Univariate and multivariate analysis were calculated for the impact of every single risk factor included in the RSS over graft failure at 1y. RESULTS Spearman coefficient showed statistically significant correlation between the score in the RSS and graft failure (P<0.05). Multivariate logistic regression analysis showed no statistically significant relationship (P>0.05) between diagnosis and lens status with graft failure. The relationship between the other risk factors studied and graft failure was significant (P<0.05), although the results for previous grafts and graft failure was unreliable. None of our patients had previous blood transfusion, thus, it had no impact. CONCLUSION After the application of multivariate analysis techniques, some risk factors do not show the expected impact over graft failure at 1y. PMID:28393027

Extending Inferential Group Analysis in Type 2 Diabetic Patients with Multivariate GLM Implemented in SPM8.

PubMed

Ferreira, Fábio S; Pereira, João M S; Duarte, João V; Castelo-Branco, Miguel

2017-01-01

Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject. Given the widespread use of SPM software in the brain imaging community, the main aim of this work is the implementation of massive multivariate inferential analysis as a toolbox in this software package. applied to the use of T1 and T2 structural data from diabetic patients and controls. This implementation was compared with the traditional ANCOVA in SPM and a similar multivariate GLM toolbox (MRM). We implemented the new toolbox and tested it by investigating brain alterations on a cohort of twenty-eight type 2 diabetes patients and twenty-six matched healthy controls, using information from both T1 and T2 weighted structural MRI scans, both separately - using standard univariate VBM - and simultaneously, with multivariate analyses. Univariate VBM replicated predominantly bilateral changes in basal ganglia and insular regions in type 2 diabetes patients. On the other hand, multivariate analyses replicated key findings of univariate results, while also revealing the thalami as additional foci of pathology. While the presented algorithm must be further optimized, the proposed toolbox is the first implementation of multivariate statistics in SPM8 as a user-friendly toolbox, which shows great potential and is ready to be validated in other clinical cohorts and modalities.

Extending Inferential Group Analysis in Type 2 Diabetic Patients with Multivariate GLM Implemented in SPM8

PubMed Central

Ferreira, Fábio S.; Pereira, João M.S.; Duarte, João V.; Castelo-Branco, Miguel

2017-01-01

Background: Although voxel based morphometry studies are still the standard for analyzing brain structure, their dependence on massive univariate inferential methods is a limiting factor. A better understanding of brain pathologies can be achieved by applying inferential multivariate methods, which allow the study of multiple dependent variables, e.g. different imaging modalities of the same subject. Objective: Given the widespread use of SPM software in the brain imaging community, the main aim of this work is the implementation of massive multivariate inferential analysis as a toolbox in this software package. applied to the use of T1 and T2 structural data from diabetic patients and controls. This implementation was compared with the traditional ANCOVA in SPM and a similar multivariate GLM toolbox (MRM). Method: We implemented the new toolbox and tested it by investigating brain alterations on a cohort of twenty-eight type 2 diabetes patients and twenty-six matched healthy controls, using information from both T1 and T2 weighted structural MRI scans, both separately – using standard univariate VBM - and simultaneously, with multivariate analyses. Results: Univariate VBM replicated predominantly bilateral changes in basal ganglia and insular regions in type 2 diabetes patients. On the other hand, multivariate analyses replicated key findings of univariate results, while also revealing the thalami as additional foci of pathology. Conclusion: While the presented algorithm must be further optimized, the proposed toolbox is the first implementation of multivariate statistics in SPM8 as a user-friendly toolbox, which shows great potential and is ready to be validated in other clinical cohorts and modalities. PMID:28761571

Investigation of Association Between Hip Osteoarthritis Susceptibility Loci and Radiographic Proximal Femur Shape

PubMed Central

Thiagarajah, Shankar; Wilkinson, J. Mark; Panoutsopoulou, Kalliope; Day‐Williams, Aaron G.; Cootes, Timothy F.; Wallis, Gillian A.; Loughlin, John; Arden, Nigel; Birrell, Fraser; Carr, Andrew; Chapman, Kay; Deloukas, Panos; Doherty, Michael; McCaskie, Andrew; Ollier, William E. R.; Rai, Ashok; Ralston, Stuart H.; Spector, Timothy D.; Valdes, Ana M.; Wallis, Gillian A.; Mark Wilkinson, J.; Zeggini, Eleftheria

2015-01-01

Objective To test whether previously reported hip morphology or osteoarthritis (OA) susceptibility loci are associated with proximal femur shape as represented by statistical shape model (SSM) modes and as univariate or multivariate quantitative traits. Methods We used pelvic radiographs and genotype data from 929 subjects with unilateral hip OA who had been recruited previously for the Arthritis Research UK Osteoarthritis Genetics Consortium genome‐wide association study. We built 3 SSMs capturing the shape variation of the OA‐unaffected proximal femur in the entire mixed‐sex cohort and for male/female‐stratified cohorts. We selected 41 candidate single‐nucleotide polymorphisms (SNPs) previously reported as being associated with hip morphology (for replication analysis) or OA (for discovery analysis) and for which genotype data were available. We performed 2 types of analysis for genotype–phenotype associations between these SNPs and the modes of the SSMs: 1) a univariate analysis using individual SSM modes and 2) a multivariate analysis using combinations of SSM modes. Results The univariate analysis identified association between rs4836732 (within the ASTN2 gene) and mode 5 of the female SSM (P = 0.0016) and between rs6976 (within the GLT8D1 gene) and mode 7 of the mixed‐sex SSM (P = 0.0003). The multivariate analysis identified association between rs5009270 (near the IFRD1 gene) and a combination of modes 3, 4, and 9 of the mixed‐sex SSM (P = 0.0004). Evidence of associations remained significant following adjustment for multiple testing. All 3 SNPs had previously been associated with hip OA. Conclusion These de novo findings suggest that rs4836732, rs6976, and rs5009270 may contribute to hip OA susceptibility by altering proximal femur shape. PMID:25939412

Risk factors for granuloma formation in children induced by tracheobronchial foreign bodies.

PubMed

Huang, Zhenghua; Zhou, Ai; Zhang, Jianya; Xie, Lisheng; Li, Qi

2015-12-01

The aim of this study was to analyze the risk factors for granuloma formation caused by plant-based tracheobronchial foreign bodies in children, and investigate the underlying pathogenesis. In this retrospective analysis of 153 cases with tracheobronchial foreign bodies (peanuts and watermelon seeds), 35 cases of granuloma formation as granulation group (G), and 118 cases of no granuloma formation as non-granulation group (NG) were studied. Clinical data pertaining to sex (S), age (A), foreign body surface smoothness (SF), foreign body shape (SH), foreign body oil release state (O), the location of foreign bodies (L), and foreign body retention time (T) were collected for statistical analysis. Univariate analysis showed no significant difference between the two groups (G and NG) with respect to S, A, SH and L. Significant factors based on univariate analysis included SF, O and T. Multivariate logistic regression analysis revealed that SF and T were independent risk factors associated with development of granuloma. SF, O and T had relationship with the granuloma formation. Local trauma caused by an irregular and sharp foreign body, and extended period of time represent the main factors causing granuloma formation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Stochastic univariate and multivariate time series analysis of PM2.5 and PM10 air pollution: A comparative case study for Plovdiv and Asenovgrad, Bulgaria

NASA Astrophysics Data System (ADS)

Gocheva-Ilieva, S.; Stoimenova, M.; Ivanov, A.; Voynikova, D.; Iliev, I.

2016-10-01

Fine particulate matter PM2.5 and PM10 air pollutants are a serious problem in many urban areas affecting both the health of the population and the environment as a whole. The availability of large data arrays for the levels of these pollutants makes it possible to perform statistical analysis, to obtain relevant information, and to find patterns within the data. Research in this field is particularly topical for a number of Bulgarian cities, European country, where in recent years regulatory air pollution health limits are constantly being exceeded. This paper examines average daily data for air pollution with PM2.5 and PM10, collected by 3 monitoring stations in the cities of Plovdiv and Asenovgrad between 2011 and 2016. The goal is to find and analyze actual relationships in data time series, to build adequate mathematical models, and to develop short-term forecasts. Modeling is carried out by stochastic univariate and multivariate time series analysis, based on Box-Jenkins methodology. The best models are selected following initial transformation of the data and using a set of standard and robust statistical criteria. The Mathematica and SPSS software were used to perform calculations. This examination showed measured concentrations of PM2.5 and PM10 in the region of Plovdiv and Asenovgrad regularly exceed permissible European and national health and safety thresholds. We obtained adequate stochastic models with high statistical fit with the data and good quality forecasting when compared against actual measurements. The mathematical approach applied provides an independent alternative to standard official monitoring and control means for air pollution in urban areas.

Ocean Wave Slope Statistics from Automated Analysis of Sun Glitter Photographs

DTIC Science & Technology

1985-06-01

8217*.... . .. , .. . .. I 1 SCONTROL MAPCROSSREF.LAdEf_ 2 Si4OuTINE HDSPLY ( HTST . No NAME. XO. XSTEPI 3 C 4 C SIUBROUTINE TO nISPLAY A UNIVARIATE HISTOGRAM...LYRANON. CSC, FESRUARV ?6s 1qA0. 7 C a C HTST z HISTOGRAM ARRAY. 9 C NT 0 ROW DIMFNSION OF HIST. to C N.1 x COLUMN DIMENSTnN OF MIST. it C 12 REAL HIST

Multi-criteria evaluation of CMIP5 GCMs for climate change impact analysis

NASA Astrophysics Data System (ADS)

Ahmadalipour, Ali; Rana, Arun; Moradkhani, Hamid; Sharma, Ashish

2017-04-01

Climate change is expected to have severe impacts on global hydrological cycle along with food-water-energy nexus. Currently, there are many climate models used in predicting important climatic variables. Though there have been advances in the field, there are still many problems to be resolved related to reliability, uncertainty, and computing needs, among many others. In the present work, we have analyzed performance of 20 different global climate models (GCMs) from Climate Model Intercomparison Project Phase 5 (CMIP5) dataset over the Columbia River Basin (CRB) in the Pacific Northwest USA. We demonstrate a statistical multicriteria approach, using univariate and multivariate techniques, for selecting suitable GCMs to be used for climate change impact analysis in the region. Univariate methods includes mean, standard deviation, coefficient of variation, relative change (variability), Mann-Kendall test, and Kolmogorov-Smirnov test (KS-test); whereas multivariate methods used were principal component analysis (PCA), singular value decomposition (SVD), canonical correlation analysis (CCA), and cluster analysis. The analysis is performed on raw GCM data, i.e., before bias correction, for precipitation and temperature climatic variables for all the 20 models to capture the reliability and nature of the particular model at regional scale. The analysis is based on spatially averaged datasets of GCMs and observation for the period of 1970 to 2000. Ranking is provided to each of the GCMs based on the performance evaluated against gridded observational data on various temporal scales (daily, monthly, and seasonal). Results have provided insight into each of the methods and various statistical properties addressed by them employed in ranking GCMs. Further; evaluation was also performed for raw GCM simulations against different sets of gridded observational dataset in the area.

Analysis of risk factors for central venous port failure in cancer patients

PubMed Central

Hsieh, Ching-Chuan; Weng, Hsu-Huei; Huang, Wen-Shih; Wang, Wen-Ke; Kao, Chiung-Lun; Lu, Ming-Shian; Wang, Chia-Siu

2009-01-01

AIM: To analyze the risk factors for central port failure in cancer patients administered chemotherapy, using univariate and multivariate analyses. METHODS: A total of 1348 totally implantable venous access devices (TIVADs) were implanted into 1280 cancer patients in this cohort study. A Cox proportional hazard model was applied to analyze risk factors for failure of TIVADs. Log-rank test was used to compare actuarial survival rates. Infection, thrombosis, and surgical complication rates (χ2 test or Fisher’s exact test) were compared in relation to the risk factors. RESULTS: Increasing age, male gender and open-ended catheter use were significant risk factors reducing survival of TIVADs as determined by univariate and multivariate analyses. Hematogenous malignancy decreased the survival time of TIVADs; this reduction was not statistically significant by univariate analysis [hazard ratio (HR) = 1.336, 95% CI: 0.966-1.849, P = 0.080)]. However, it became a significant risk factor by multivariate analysis (HR = 1.499, 95% CI: 1.079-2.083, P = 0.016) when correlated with variables of age, sex and catheter type. Close-ended (Groshong) catheters had a lower thrombosis rate than open-ended catheters (2.5% vs 5%, P = 0.015). Hematogenous malignancy had higher infection rates than solid malignancy (10.5% vs 2.5%, P < 0.001). CONCLUSION: Increasing age, male gender, open-ended catheters and hematogenous malignancy were risk factors for TIVAD failure. Close-ended catheters had lower thrombosis rates and hematogenous malignancy had higher infection rates. PMID:19787834

Lower education level is a major risk factor for peritonitis incidence in chronic peritoneal dialysis patients: a retrospective cohort study with 12-year follow-up.

PubMed

Chern, Yahn-Bor; Ho, Pei-Shan; Kuo, Li-Chueh; Chen, Jin-Bor

2013-01-01

Peritoneal dialysis (PD)-related peritonitis remains an important complication in PD patients, potentially causing technique failure and influencing patient outcome. To date, no comprehensive study in the Taiwanese PD population has used a time-dependent statistical method to analyze the factors associated with PD-related peritonitis. Our single-center retrospective cohort study, conducted in southern Taiwan between February 1999 and July 2010, used time-dependent statistical methods to analyze the factors associated with PD-related peritonitis. The study recruited 404 PD patients for analysis, 150 of whom experienced at least 1 episode of peritonitis during the follow-up period. The incidence rate of peritonitis was highest during the first 6 months after PD start. A comparison of patients in the two groups (peritonitis vs null-peritonitis) by univariate analysis showed that the peritonitis group included fewer men (p = 0.048) and more patients of older age (≥65 years, p = 0.049). In addition, patients who had never received compulsory education showed a statistically higher incidence of PD-related peritonitis in the univariate analysis (p = 0.04). A proportional hazards model identified education level (less than elementary school vs any higher education level) as having an independent association with PD-related peritonitis [hazard ratio (HR): 1.45; 95% confidence interval (CI): 1.01 to 2.06; p = 0.045). Comorbidities measured using the Charlson comorbidity index (score >2 vs ≤2) showed borderline statistical significance (HR: 1.44; 95% CI: 1.00 to 2.13; p = 0.053). A lower education level is a major risk factor for PD-related peritonitis independent of age, sex, hypoalbuminemia, and comorbidities. Our study emphasizes that a comprehensive PD education program is crucial for PD patients with a lower education level.

Moving beyond Univariate Post-Hoc Testing in Exercise Science: A Primer on Descriptive Discriminate Analysis

ERIC Educational Resources Information Center

Barton, Mitch; Yeatts, Paul E.; Henson, Robin K.; Martin, Scott B.

2016-01-01

There has been a recent call to improve data reporting in kinesiology journals, including the appropriate use of univariate and multivariate analysis techniques. For example, a multivariate analysis of variance (MANOVA) with univariate post hocs and a Bonferroni correction is frequently used to investigate group differences on multiple dependent…

Risk factors for superficial surgical site infection after elective rectal cancer resection: a multivariate analysis of 8880 patients from the American College of Surgeons National Surgical Quality Improvement Program database.

PubMed

Sutton, Elie; Miyagaki, Hiromichi; Bellini, Geoffrey; Shantha Kumara, H M C; Yan, Xiaohong; Howe, Brett; Feigel, Amanda; Whelan, Richard L

2017-01-01

Superficial surgical site infection (sSSI) is one of the most common complications after colorectal resection. The goal of this study was to determine the comorbidities and operative characteristics that place patients at risk for sSSI in patients who underwent rectal cancer resection. The American College of Surgeons National Surgical Quality Improvement Program database was queried (via diagnosis and Current Procedural Terminology codes) for patients with rectal cancer who underwent elective resection between 2005 and 2012. Patients for whom data concerning 27 demographic factors, comorbidities, and operative characteristics were available were eligible. A univariate and multivariate analysis was performed to identify possible risk factors for sSSI. A total of 8880 patients met the entry criteria and were included. sSSIs were diagnosed in 861 (9.7%) patients. Univariate analysis found 14 patients statistically significant risk factors for sSSI. Multivariate analysis revealed the following risk factors: male gender, body mass index (BMI) >30, current smoking, history of chronic obstructive pulmonary disease (COPD), American Society of Anesthesiologists III/IV, abdominoperineal resection (APR), stoma formation, open surgery (versus laparoscopic), and operative time >217 min. The greatest difference in sSSI rates was noted in patients with COPD (18.9 versus 9.5%). Of note, 54.2% of sSSIs was noted after hospital discharge. With regard to the timing of presentation, univariate analysis revealed a statistically significant delay in sSSI presentation in patients with the following factors and/or characteristics: BMI <30, previous radiation therapy (RT), APR, minimally invasive surgery, and stoma formation. Multivariate analysis suggested that only laparoscopic surgery (versus open) and preoperative RT were risk factors for delay. Rectal cancer resections are associated with a high incidence of sSSIs, over half of which are noted after discharge. Nine patient and operative characteristics, including smoking, BMI, COPD, APR, and open surgery were found to be significant risk factors for SSI on multivariate analysis. Furthermore, sSSI presentation in patients who had laparoscopic surgery and those who had preoperative RT is significantly delayed for unclear reasons. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors Influencing Cecal Intubation Time during Retrograde Approach Single-Balloon Enteroscopy

PubMed Central

Chen, Peng-Jen; Shih, Yu-Lueng; Huang, Hsin-Hung; Hsieh, Tsai-Yuan

2014-01-01

Background and Aim. The predisposing factors for prolonged cecal intubation time (CIT) during colonoscopy have been well identified. However, the factors influencing CIT during retrograde SBE have not been addressed. The aim of this study was to determine the factors influencing CIT during retrograde SBE. Methods. We investigated patients who underwent retrograde SBE at a medical center from January 2011 to March 2014. The medical charts and SBE reports were reviewed. The patients' characteristics and procedure-associated data were recorded. These data were analyzed with univariate analysis as well as multivariate logistic regression analysis to identify the possible predisposing factors. Results. We enrolled 66 patients into this study. The median CIT was 17.4 minutes. With univariate analysis, there was no statistical difference in age, sex, BMI, or history of abdominal surgery, except for bowel preparation (P = 0.021). Multivariate logistic regression analysis showed that inadequate bowel preparation (odds ratio 30.2, 95% confidence interval 4.63–196.54; P < 0.001) was the independent predisposing factors for prolonged CIT during retrograde SBE. Conclusions. For experienced endoscopist, inadequate bowel preparation was the independent predisposing factor for prolonged CIT during retrograde SBE. PMID:25505904

Prematurity and fetal lung response after tracheal occlusion in fetuses with severe congenital diaphragmatic hernia.

PubMed

Sananes, Nicolas; Rodo, Carlota; Peiro, Jose Luis; Britto, Ingrid Schwach Werneck; Sangi-Haghpeykar, Haleh; Favre, Romain; Joal, Arnaud; Gaudineau, Adrien; Silva, Marcos Marques da; Tannuri, Uenis; Zugaib, Marcelo; Carreras, Elena; Ruano, Rodrigo

2016-09-01

To evaluate the independent association of fetal pulmonary response and prematurity to postnatal outcomes after fetal tracheal occlusion for congenital diaphragmatic hernia. Fetal pulmonary response, prematurity (<37 weeks at delivery) and extreme prematurity (<32 weeks at delivery) were evaluated and compared between survivors and non-survivors at 6 months of life. Multivariable analysis was conducted with generalized linear mixed models for variables significantly associated with survival in univariate analysis. Eighty-four infants were included, of whom 40 survived (47.6%) and 44 died (52.4%). Univariate analysis demonstrated that survival was associated with greater lung response (p=0.006), and the absence of extreme preterm delivery (p=0.044). In multivariable analysis, greater pulmonary response after FETO was an independent predictor of survival (aOR 1.87, 95% CI 1.08-3.33, p=0.023), whereas the presence of extreme prematurity was not statistically associated with mortality after controlling for fetal pulmonary response (aOR 0.52, 95% CI 0.12-2.30, p=0.367). Fetal pulmonary response after FETO is the most important factor associated with survival, independently from the gestational age at delivery.

Multivariate random regression analysis for body weight and main morphological traits in genetically improved farmed tilapia (Oreochromis niloticus).

PubMed

He, Jie; Zhao, Yunfeng; Zhao, Jingli; Gao, Jin; Han, Dandan; Xu, Pao; Yang, Runqing

2017-11-02

Because of their high economic importance, growth traits in fish are under continuous improvement. For growth traits that are recorded at multiple time-points in life, the use of univariate and multivariate animal models is limited because of the variable and irregular timing of these measures. Thus, the univariate random regression model (RRM) was introduced for the genetic analysis of dynamic growth traits in fish breeding. We used a multivariate random regression model (MRRM) to analyze genetic changes in growth traits recorded at multiple time-point of genetically-improved farmed tilapia. Legendre polynomials of different orders were applied to characterize the influences of fixed and random effects on growth trajectories. The final MRRM was determined by optimizing the univariate RRM for the analyzed traits separately via penalizing adaptively the likelihood statistical criterion, which is superior to both the Akaike information criterion and the Bayesian information criterion. In the selected MRRM, the additive genetic effects were modeled by Legendre polynomials of three orders for body weight (BWE) and body length (BL) and of two orders for body depth (BD). By using the covariance functions of the MRRM, estimated heritabilities were between 0.086 and 0.628 for BWE, 0.155 and 0.556 for BL, and 0.056 and 0.607 for BD. Only heritabilities for BD measured from 60 to 140 days of age were consistently higher than those estimated by the univariate RRM. All genetic correlations between growth time-points exceeded 0.5 for either single or pairwise time-points. Moreover, correlations between early and late growth time-points were lower. Thus, for phenotypes that are measured repeatedly in aquaculture, an MRRM can enhance the efficiency of the comprehensive selection for BWE and the main morphological traits.

The issue of multiple univariate comparisons in the context of neuroelectric brain mapping: an application in a neuromarketing experiment.

PubMed

Vecchiato, G; De Vico Fallani, F; Astolfi, L; Toppi, J; Cincotti, F; Mattia, D; Salinari, S; Babiloni, F

2010-08-30

This paper presents some considerations about the use of adequate statistical techniques in the framework of the neuroelectromagnetic brain mapping. With the use of advanced EEG/MEG recording setup involving hundred of sensors, the issue of the protection against the type I errors that could occur during the execution of hundred of univariate statistical tests, has gained interest. In the present experiment, we investigated the EEG signals from a mannequin acting as an experimental subject. Data have been collected while performing a neuromarketing experiment and analyzed with state of the art computational tools adopted in specialized literature. Results showed that electric data from the mannequin's head presents statistical significant differences in power spectra during the visualization of a commercial advertising when compared to the power spectra gathered during a documentary, when no adjustments were made on the alpha level of the multiple univariate tests performed. The use of the Bonferroni or Bonferroni-Holm adjustments returned correctly no differences between the signals gathered from the mannequin in the two experimental conditions. An partial sample of recently published literature on different neuroscience journals suggested that at least the 30% of the papers do not use statistical protection for the type I errors. While the occurrence of type I errors could be easily managed with appropriate statistical techniques, the use of such techniques is still not so largely adopted in the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Assessing signal-to-noise in quantitative proteomics: multivariate statistical analysis in DIGE experiments.

PubMed

Friedman, David B

2012-01-01

All quantitative proteomics experiments measure variation between samples. When performing large-scale experiments that involve multiple conditions or treatments, the experimental design should include the appropriate number of individual biological replicates from each condition to enable the distinction between a relevant biological signal from technical noise. Multivariate statistical analyses, such as principal component analysis (PCA), provide a global perspective on experimental variation, thereby enabling the assessment of whether the variation describes the expected biological signal or the unanticipated technical/biological noise inherent in the system. Examples will be shown from high-resolution multivariable DIGE experiments where PCA was instrumental in demonstrating biologically significant variation as well as sample outliers, fouled samples, and overriding technical variation that would not be readily observed using standard univariate tests.

A Simple Simulation Technique for Nonnormal Data with Prespecified Skewness, Kurtosis, and Covariance Matrix.

PubMed

Foldnes, Njål; Olsson, Ulf Henning

2016-01-01

We present and investigate a simple way to generate nonnormal data using linear combinations of independent generator (IG) variables. The simulated data have prespecified univariate skewness and kurtosis and a given covariance matrix. In contrast to the widely used Vale-Maurelli (VM) transform, the obtained data are shown to have a non-Gaussian copula. We analytically obtain asymptotic robustness conditions for the IG distribution. We show empirically that popular test statistics in covariance analysis tend to reject true models more often under the IG transform than under the VM transform. This implies that overly optimistic evaluations of estimators and fit statistics in covariance structure analysis may be tempered by including the IG transform for nonnormal data generation. We provide an implementation of the IG transform in the R environment.

Quantile Regression for Recurrent Gap Time Data

PubMed Central

Luo, Xianghua; Huang, Chiung-Yu; Wang, Lan

2014-01-01

Summary Evaluating covariate effects on gap times between successive recurrent events is of interest in many medical and public health studies. While most existing methods for recurrent gap time analysis focus on modeling the hazard function of gap times, a direct interpretation of the covariate effects on the gap times is not available through these methods. In this article, we consider quantile regression that can provide direct assessment of covariate effects on the quantiles of the gap time distribution. Following the spirit of the weighted risk-set method by Luo and Huang (2011, Statistics in Medicine 30, 301–311), we extend the martingale-based estimating equation method considered by Peng and Huang (2008, Journal of the American Statistical Association 103, 637–649) for univariate survival data to analyze recurrent gap time data. The proposed estimation procedure can be easily implemented in existing software for univariate censored quantile regression. Uniform consistency and weak convergence of the proposed estimators are established. Monte Carlo studies demonstrate the effectiveness of the proposed method. An application to data from the Danish Psychiatric Central Register is presented to illustrate the methods developed in this article. PMID:23489055

Multiple Hypothesis Testing for Experimental Gingivitis Based on Wilcoxon Signed Rank Statistics

PubMed Central

Preisser, John S.; Sen, Pranab K.; Offenbacher, Steven

2011-01-01

Dental research often involves repeated multivariate outcomes on a small number of subjects for which there is interest in identifying outcomes that exhibit change in their levels over time as well as to characterize the nature of that change. In particular, periodontal research often involves the analysis of molecular mediators of inflammation for which multivariate parametric methods are highly sensitive to outliers and deviations from Gaussian assumptions. In such settings, nonparametric methods may be favored over parametric ones. Additionally, there is a need for statistical methods that control an overall error rate for multiple hypothesis testing. We review univariate and multivariate nonparametric hypothesis tests and apply them to longitudinal data to assess changes over time in 31 biomarkers measured from the gingival crevicular fluid in 22 subjects whereby gingivitis was induced by temporarily withholding tooth brushing. To identify biomarkers that can be induced to change, multivariate Wilcoxon signed rank tests for a set of four summary measures based upon area under the curve are applied for each biomarker and compared to their univariate counterparts. Multiple hypothesis testing methods with choice of control of the false discovery rate or strong control of the family-wise error rate are examined. PMID:21984957

Analysis of Cross-Sectional Univariate Measurements for Family Dyads Using Linear Mixed Modeling

PubMed Central

Knafl, George J.; Dixon, Jane K.; O'Malley, Jean P.; Grey, Margaret; Deatrick, Janet A.; Gallo, Agatha M.; Knafl, Kathleen A.

2010-01-01

Outcome measurements from members of the same family are likely correlated. Such intrafamilial correlation (IFC) is an important dimension of the family as a unit but is not always accounted for in analyses of family data. This article demonstrates the use of linear mixed modeling to account for IFC in the important special case of univariate measurements for family dyads collected at a single point in time. Example analyses of data from partnered parents having a child with a chronic condition on their child's adaptation to the condition and on the family's general functioning and management of the condition are provided. Analyses of this kind are reasonably straightforward to generate with popular statistical tools. Thus, it is recommended that IFC be reported as standard practice reflecting the fact that a family dyad is more than just the aggregate of two individuals. Moreover, not accounting for IFC can affect the conclusions. PMID:19307316

Univariate and bivariate likelihood-based meta-analysis methods performed comparably when marginal sensitivity and specificity were the targets of inference.

PubMed

Dahabreh, Issa J; Trikalinos, Thomas A; Lau, Joseph; Schmid, Christopher H

2017-03-01

To compare statistical methods for meta-analysis of sensitivity and specificity of medical tests (e.g., diagnostic or screening tests). We constructed a database of PubMed-indexed meta-analyses of test performance from which 2 × 2 tables for each included study could be extracted. We reanalyzed the data using univariate and bivariate random effects models fit with inverse variance and maximum likelihood methods. Analyses were performed using both normal and binomial likelihoods to describe within-study variability. The bivariate model using the binomial likelihood was also fit using a fully Bayesian approach. We use two worked examples-thoracic computerized tomography to detect aortic injury and rapid prescreening of Papanicolaou smears to detect cytological abnormalities-to highlight that different meta-analysis approaches can produce different results. We also present results from reanalysis of 308 meta-analyses of sensitivity and specificity. Models using the normal approximation produced sensitivity and specificity estimates closer to 50% and smaller standard errors compared to models using the binomial likelihood; absolute differences of 5% or greater were observed in 12% and 5% of meta-analyses for sensitivity and specificity, respectively. Results from univariate and bivariate random effects models were similar, regardless of estimation method. Maximum likelihood and Bayesian methods produced almost identical summary estimates under the bivariate model; however, Bayesian analyses indicated greater uncertainty around those estimates. Bivariate models produced imprecise estimates of the between-study correlation of sensitivity and specificity. Differences between methods were larger with increasing proportion of studies that were small or required a continuity correction. The binomial likelihood should be used to model within-study variability. Univariate and bivariate models give similar estimates of the marginal distributions for sensitivity and specificity. Bayesian methods fully quantify uncertainty and their ability to incorporate external evidence may be useful for imprecisely estimated parameters. Copyright © 2017 Elsevier Inc. All rights reserved.

Metabolomic differentiation of maca (Lepidium meyenii) accessions cultivated under different conditions using NMR and chemometric analysis.

PubMed

Zhao, Jianping; Avula, Bharathi; Chan, Michael; Clément, Céline; Kreuzer, Michael; Khan, Ikhlas A

2012-01-01

To gain insights on the effects of color type, cultivation history, and growing site on the composition alterations of maca (Lepidium meyenii Walpers) hypocotyls, NMR profiling combined with chemometric analysis was applied to investigate the metabolite variability in different maca accessions. Maca hypocotyls with different colors (yellow, pink, violet, and lead-colored) cultivated at different geographic sites and different areas were examined for differences in metabolite expression. Differentiations of the maca accessions grown under the different cultivation conditions were determined by principle component analyses (PCAs) which were performed on the datasets derived from their ¹H NMR spectra. A total of 16 metabolites were identified by NMR analysis, and the changes in metabolite levels in relation to the color types and growing conditions of maca hypocotyls were evaluated using univariate statistical analysis. In addition, the changes of the correlation pattern among the metabolites identified in the maca accessions planted at the two different sites were examined. The results from both multivariate and univariate analysis indicated that the planting site was the major determining factor with regards to metabolite variations in maca hypocotyls, while the color of maca accession seems to be of minor importance in this respect. © Georg Thieme Verlag KG Stuttgart · New York.

Prognostic value of stromal decorin expression in patients with breast cancer: a meta-analysis.

PubMed

Li, Shuang-Jiang; Chen, Da-Li; Zhang, Wen-Biao; Shen, Cheng; Che, Guo-Wei

2015-11-01

Numbers of studies have investigated the biological functions of decorin (DCN) in oncogenesis, tumor progression, angiogenesis and metastasis. Although many of them aim to highlight the prognostic value of stromal DCN expression in breast cancer, some controversial results still exist and a consensus has not been reached until now. Therefore, our meta-analysis aims to determine the prognostic significance of stromal DCN expression in breast cancer patients. PubMed, EMBASE, the Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched for full-text literatures met out inclusion criteria. We applied the hazard ratio (HR) with 95% confidence interval (CI) as the appropriate summarized statistics. Q-test and I(2) statistic were employed to estimate the level of heterogeneity across the included studies. Sensitivity analysis was conducted to further identify the possible origins of heterogeneity. The publication bias was detected by Begg's test and Egger's test. There were three English literatures (involving 6 studies) included into our meta-analysis. On the one hand, both the summarized outcomes based on univariate analysis (HR: 0.513; 95% CI: 0.406-0.648; P<0.001) and multivariate analysis (HR: 0.544; 95% CI: 0.388-0.763; P<0.001) indicated that stromal DCN expression could promise the high cancer-specific survival (CSS) of breast cancer patients. On the other hand, both the summarized outcomes based on univariate analysis (HR: 0.504; 95% CI: 0.389-0.651; P<0.001) and multivariate analysis (HR: 0.568; 95% CI: 0.400-0.806; P=0.002) also indicated that stromal DCN expression was positively associated with high disease-free survival (DFS) of breast cancer patients. No significant heterogeneity or publication bias was observed within this meta-analysis. The present evidences indicate that high stromal DCN expression can significantly predict the good prognosis in patients with breast cancer. The discoveries from our meta-analysis have better be confirmed in the updated review pooling more relevant investigations in the future.

A fast boosting-based screening method for large-scale association study in complex traits with genetic heterogeneity.

PubMed

Wang, Lu-Yong; Fasulo, D

2006-01-01

Genome-wide association study for complex diseases will generate massive amount of single nucleotide polymorphisms (SNPs) data. Univariate statistical test (i.e. Fisher exact test) was used to single out non-associated SNPs. However, the disease-susceptible SNPs may have little marginal effects in population and are unlikely to retain after the univariate tests. Also, model-based methods are impractical for large-scale dataset. Moreover, genetic heterogeneity makes the traditional methods harder to identify the genetic causes of diseases. A more recent random forest method provides a more robust method for screening the SNPs in thousands scale. However, for more large-scale data, i.e., Affymetrix Human Mapping 100K GeneChip data, a faster screening method is required to screening SNPs in whole-genome large scale association analysis with genetic heterogeneity. We propose a boosting-based method for rapid screening in large-scale analysis of complex traits in the presence of genetic heterogeneity. It provides a relatively fast and fairly good tool for screening and limiting the candidate SNPs for further more complex computational modeling task.

PredPsych: A toolbox for predictive machine learning-based approach in experimental psychology research.

PubMed

Koul, Atesh; Becchio, Cristina; Cavallo, Andrea

2017-12-12

Recent years have seen an increased interest in machine learning-based predictive methods for analyzing quantitative behavioral data in experimental psychology. While these methods can achieve relatively greater sensitivity compared to conventional univariate techniques, they still lack an established and accessible implementation. The aim of current work was to build an open-source R toolbox - "PredPsych" - that could make these methods readily available to all psychologists. PredPsych is a user-friendly, R toolbox based on machine-learning predictive algorithms. In this paper, we present the framework of PredPsych via the analysis of a recently published multiple-subject motion capture dataset. In addition, we discuss examples of possible research questions that can be addressed with the machine-learning algorithms implemented in PredPsych and cannot be easily addressed with univariate statistical analysis. We anticipate that PredPsych will be of use to researchers with limited programming experience not only in the field of psychology, but also in that of clinical neuroscience, enabling computational assessment of putative bio-behavioral markers for both prognosis and diagnosis.

Addressing Spatial Dependence Bias in Climate Model Simulations—An Independent Component Analysis Approach

NASA Astrophysics Data System (ADS)

Nahar, Jannatun; Johnson, Fiona; Sharma, Ashish

2018-02-01

Conventional bias correction is usually applied on a grid-by-grid basis, meaning that the resulting corrections cannot address biases in the spatial distribution of climate variables. To solve this problem, a two-step bias correction method is proposed here to correct time series at multiple locations conjointly. The first step transforms the data to a set of statistically independent univariate time series, using a technique known as independent component analysis (ICA). The mutually independent signals can then be bias corrected as univariate time series and back-transformed to improve the representation of spatial dependence in the data. The spatially corrected data are then bias corrected at the grid scale in the second step. The method has been applied to two CMIP5 General Circulation Model simulations for six different climate regions of Australia for two climate variables—temperature and precipitation. The results demonstrate that the ICA-based technique leads to considerable improvements in temperature simulations with more modest improvements in precipitation. Overall, the method results in current climate simulations that have greater equivalency in space and time with observational data.

Descriptor selection for banana accessions based on univariate and multivariate analysis.

PubMed

Brandão, L P; Souza, C P F; Pereira, V M; Silva, S O; Santos-Serejo, J A; Ledo, C A S; Amorim, E P

2013-05-14

Our objective was to establish a minimum number of morphological descriptors for the characterization of banana germplasm and evaluate the efficiency of removal of redundant characters, based on univariate and multivariate statistical analyses. Phenotypic characterization was made of 77 accessions from Bahia, Brazil, using 92 descriptors. The selection of the descriptors was carried out by principal components analysis (quantitative) and by entropy (multi-category). Efficiency of elimination was analyzed by a comparative study between the clusters formed, taking into consideration all 92 descriptors and smaller groups. The selected descriptors were analyzed with the Ward-MLM procedure and a combined matrix formed by the Gower algorithm. We were able to reduce the number of descriptors used for characterizing the banana germplasm (42%). The correlation between the matrices considering the 92 descriptors and the selected ones was 0.82, showing that the reduction in the number of descriptors did not influence estimation of genetic variability between the banana accessions. We conclude that removing these descriptors caused no loss of information, considering the groups formed from pre-established criteria, including subgroup/subspecies.

Polypharmacy as a risk for fall occurrence in geriatric outpatients.

PubMed

Kojima, Taro; Akishita, Masahiro; Nakamura, Tetsuro; Nomura, Kazushi; Ogawa, Sumito; Iijima, Katsuya; Eto, Masato; Ouchi, Yasuyoshi

2012-07-01

To investigate the predictors of falls, such as comorbidity and medication, in geriatric outpatients in a longitudinal observational study. A total of 172 outpatients (45 men and 126 women, mean age 76.9 ± 7.0 years) were evaluated. Physical examination, clinical history and medication profile were obtained from each patient at baseline. These patients were followed for up to 2 years and falls were self-reported to their physicians. The factors associated with falls were analyzed statistically. A total of 32 patients experienced falls within 2 years. On univariate analysis, older age, osteoporosis, number of comorbid conditions and number of drugs were significantly associated with falls within 2 years. On multiple logistic regression analysis, the number of drugs was associated with falls, independent of age, sex, number of comorbid conditions and other factors that were significantly associated in univariate analysis. A receiver-operator curve evaluating the optimal cut-off value for the number of drugs showed that taking five or more drugs was a significant risk. In geriatric outpatients, polypharmacy is associated with falls. Intervention studies are needed to clarify the causal relationship between polypharmacy, comorbidity and falls. © 2011 Japan Geriatrics Society.

[Incidence and surgical wound infection risk factors in breast cancer surgery].

PubMed

Lefebvre, D; Penel, N; Deberles, M F; Fournier, C

2000-11-18

In order to evaluate occurrence and risk factors for wound infection (WI) in breast cancer surgery, we carried out a prospective study. From September 1996 through April 1997, an infection control physician prospectively evaluated 542 wounds of all patients having breast cancer surgery at the Oscar Lambret Cancer Center. WI was defined as a wound with pus. Antibiotic prophylaxis was given in case of immediate breast reconstruction. Statistical evaluation was performed using the c < or = test for categorial data and non-parametric Mann-Whitney test for continuous data. In univariate analysis, differences were considered significant at p < 0.01. The overall WI rate was 3.51% (19/352). In univariate analysis, risk factors for WI were: total preoperative hospital stay (p = 0.01), previous chemotherapy (p = 0.01), previous oncologic surgery (p = 0.03) and immediate breast reconstruction (p = 0.002). In mutivariate analysis, we observed two independent predictive factors for WI: previous chemotherapy (p = 0.05) and immediate breast reconstruction (p = 0.02). Previous anticancer chemotherapy was a major risk factor. In these cases, a phase III trial could confirm efficacy of standard antibiotic prophylaxis. Breast reconstruction was the second major risk factor. Standard antibiotic prophylaxis (used in our study) was insufficient.

Predictive factors of clinical response in steroid-refractory ulcerative colitis treated with granulocyte-monocyte apheresis

PubMed Central

D'Ovidio, Valeria; Meo, Donatella; Viscido, Angelo; Bresci, Giampaolo; Vernia, Piero; Caprilli, Renzo

2011-01-01

AIM: To identify factors predicting the clinical response of ulcerative colitis patients to granulocyte-monocyte apheresis (GMA). METHODS: Sixty-nine ulcerative colitis patients (39 F, 30 M) dependent upon/refractory to steroids were treated with GMA. Steroid dependency, clinical activity index (CAI), C reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), values at baseline, use of immunosuppressant, duration of disease, and age and extent of disease were considered for statistical analysis as predictive factors of clinical response. Univariate and multivariate logistic regression models were used. RESULTS: In the univariate analysis, CAI (P = 0.039) and ESR (P = 0.017) levels at baseline were singled out as predictive of clinical remission. In the multivariate analysis steroid dependency [Odds ratio (OR) = 0.390, 95% Confidence interval (CI): 0.176-0.865, Wald 5.361, P = 0.0160] and low CAI levels at baseline (4 < CAI < 7) (OR = 0.770, 95% CI: 0.425-1.394, Wald 3.747, P = 0.028) proved to be effective as factors predicting clinical response. CONCLUSION: GMA may be a valid therapeutic option for steroid-dependent ulcerative colitis patients with mild-moderate disease and its clinical efficacy seems to persist for 12 mo. PMID:21528055

Statistical power of intervention analyses: simulation and empirical application to treated lumber prices

Treesearch

Jeffrey P. Prestemon

2009-01-01

Timber product markets are subject to large shocks deriving from natural disturbances and policy shifts. Statistical modeling of shocks is often done to assess their economic importance. In this article, I simulate the statistical power of univariate and bivariate methods of shock detection using time series intervention models. Simulations show that bivariate methods...

Improving mass-univariate analysis of neuroimaging data by modelling important unknown covariates: Application to Epigenome-Wide Association Studies.

PubMed

Guillaume, Bryan; Wang, Changqing; Poh, Joann; Shen, Mo Jun; Ong, Mei Lyn; Tan, Pei Fang; Karnani, Neerja; Meaney, Michael; Qiu, Anqi

2018-06-01

Statistical inference on neuroimaging data is often conducted using a mass-univariate model, equivalent to fitting a linear model at every voxel with a known set of covariates. Due to the large number of linear models, it is challenging to check if the selection of covariates is appropriate and to modify this selection adequately. The use of standard diagnostics, such as residual plotting, is clearly not practical for neuroimaging data. However, the selection of covariates is crucial for linear regression to ensure valid statistical inference. In particular, the mean model of regression needs to be reasonably well specified. Unfortunately, this issue is often overlooked in the field of neuroimaging. This study aims to adopt the existing Confounder Adjusted Testing and Estimation (CATE) approach and to extend it for use with neuroimaging data. We propose a modification of CATE that can yield valid statistical inferences using Principal Component Analysis (PCA) estimators instead of Maximum Likelihood (ML) estimators. We then propose a non-parametric hypothesis testing procedure that can improve upon parametric testing. Monte Carlo simulations show that the modification of CATE allows for more accurate modelling of neuroimaging data and can in turn yield a better control of False Positive Rate (FPR) and Family-Wise Error Rate (FWER). We demonstrate its application to an Epigenome-Wide Association Study (EWAS) on neonatal brain imaging and umbilical cord DNA methylation data obtained as part of a longitudinal cohort study. Software for this CATE study is freely available at http://www.bioeng.nus.edu.sg/cfa/Imaging_Genetics2.html. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Dependence of drivers affects risks associated with compound events

NASA Astrophysics Data System (ADS)

Zscheischler, Jakob; Seneviratne, Sonia I.

2017-04-01

Compound climate extremes are receiving increasing attention because of their disproportionate impacts on humans and ecosystems. Risks assessments, however, generally focus on univariate statistics even when multiple stressors are considered. Concurrent extreme droughts and heatwaves have been observed to cause a suite of extreme impacts on natural and human systems alike. For example, they can substantially affect vegetation health, prompting tree mortality, and thereby facilitating insect outbreaks and fires. In addition, hot droughts have the potential to trigger and intensify fires and can cause severe economical damage. By promoting disease spread, extremely hot and dry conditions also strongly affect human health. We analyse the co-occurrence of dry and hot summers and show that these are strongly correlated for many regions, inducing a much higher frequency of concurrent hot and dry summers than what would be assumed from the independent combination of the univariate statistics. Our results demonstrate how the dependence structure between variables affects the occurrence frequency of multivariate extremes. Assessments based on univariate statistics can thus strongly underestimate risks associated with given extremes, if impacts depend on multiple (dependent) variables. We conclude that a multivariate perspective is necessary in order to appropriately assess changes in climate extremes and their impacts, and to design adaptation strategies.

Robotic partial nephrectomy shortens warm ischemia time, reducing suturing time kinetics even for an experienced laparoscopic surgeon: a comparative analysis.

PubMed

Faria, Eliney F; Caputo, Peter A; Wood, Christopher G; Karam, Jose A; Nogueras-González, Graciela M; Matin, Surena F

2014-02-01

Laparoscopic and robotic partial nephrectomy (LPN and RPN) are strongly related to influence of tumor complexity and learning curve. We analyzed a consecutive experience between RPN and LPN to discern if warm ischemia time (WIT) is in fact improved while accounting for these two confounding variables and if so by which particular aspect of WIT. This is a retrospective analysis of consecutive procedures performed by a single surgeon between 2002-2008 (LPN) and 2008-2012 (RPN). Specifically, individual steps, including tumor excision, suturing of intrarenal defect, and parenchyma, were recorded at the time of surgery. Multivariate and univariate analyzes were used to evaluate influence of learning curve, tumor complexity, and time kinetics of individual steps during WIT, to determine their influence in WIT. Additionally, we considered the effect of RPN on the learning curve. A total of 146 LPNs and 137 RPNs were included. Considering renal function, WIT, suturing time, renorrhaphy time were found statistically significant differences in favor of RPN (p < 0.05). In the univariate analysis, surgical procedure, learning curve, clinical tumor size, and RENAL nephrometry score were statistically significant predictors for WIT (p < 0.05). RPN decreased the WIT on average by approximately 7 min compared to LPN even when adjusting for learning curve, tumor complexity, and both together (p < 0.001). We found RPN was associated with a shorter WIT when controlling for influence of the learning curve and tumor complexity. The time required for tumor excision was not shortened but the time required for suturing steps was significantly shortened.

Dual diagnosis vs. triple diagnosis in HIV: a comparative study to evaluate the differences in psychopathology and suicidal risk in HIV positive male subjects.

PubMed

Gupta, M; Kumar, K; Garg, P D

2013-12-01

The problem of triple diagnosis of HIV, substance abuse and psychiatric disorders is a complex one with difficult solutions. HIV disease progression is affected by substance use as well as psychiatric illness burden due to both direct as well as indirect factors. Continuing substance abuse with poor drug adherence coexists with psychiatric disorders leading to increased morbidity and mortality. A total of 100 HIV positive subjects comprising of two groups each having 50 subjects with and without substance abuse were assessed using detailed history, mental state examination, WHO schedule for clinical assessment in neuropsychiatry (SCAN 2.0) and Beck's Scale for Suicidal Ideation (BSS). Statistical analysis used Chi-Square test, Fischer's exact test, Student's t-test, Pearson's correlation coefficient, univariate and multiple regression analysis, univariate and multiple logistic regression analysis. p-Value<0.05 was considered to denote statistical significance. Subjects with substance use disorder had higher rates of psychiatric morbidity (52% vs. 24%, 95% CI=0.5200, p<0.05). The rate of antiretroviral therapy default was almost double in subjects with substance abuse, as compared to subjects without substance use. Suicidal risk was significantly increased (p<0.05) in subjects with co-morbid medical disorders but substance abuse did not increase the risk. Substance abuse inflicts a much greater burden on HIV positive individuals as compared to subjects without substance use. Concomitant substance abuse resulted in significantly increased duration of illness and psychiatric morbidity. Copyright © 2013 Elsevier B.V. All rights reserved.

Is Pregnancy Associated with Severe Dengue? A Review of Data from the Rio de Janeiro Surveillance Information System

PubMed Central

Machado, Carolina Romero; Machado, Elizabeth Stankiewicz; Rohloff, Roger Denis; Azevedo, Marina; Campos, Dayse Pereira; de Oliveira, Robson Bruniera; Brasil, Patrícia

2013-01-01

Background Dengue is a reportable disease in Brazil; however, pregnancy has been included in the application form of the Brazilian notification information system only after 2006. To estimate the severity of maternal dengue infection, the available data that were compiled from January 2007 to December 2008 by the official surveillance information system of the city of Rio de Janeiro were reviewed. Methods and Principal Findings During the study period, 151,604 cases of suspected dengue infection were reported. Five hundred sixty-one women in their reproductive age (15–49 years) presented with dengue infection; 99 (18.1%) pregnant and 447 (81.9%) non-pregnant women were analyzed. Dengue cases were categorized using the 1997 WHO classification system, and DHF/DSS were considered severe disease. The Mann-Whitney test was used to compare maternal age, according to gestational period, and severity of disease. A chi-square test was utilized to evaluate the differences in the proportion of dengue severity between pregnant and non-pregnant women. Univariate analysis was performed to compare outcome variables (severe dengue and non-severe dengue) and explanatory variables (pregnancy, gestational age and trimester) using the Wald test. A multivariate analysis was performed to assess the independence of statistically significant variables in the univariate analysis. A p-value<0.05 was considered statistically significant. A higher percentage of severe dengue infection among pregnant women was found, p = 0.0001. Final analysis demonstrated that pregnant women are 3.4 times more prone to developing severe dengue (OR: 3.38; CI: 2.10–5.42). Mortality among pregnant women was superior to non-pregnant women. Conclusion Pregnant women have an increased risk of developing severe dengue infection and dying of dengue. PMID:23675548

Chordee and Penile Shortening Rather Than Voiding Function Are Associated With Patient Dissatisfaction After Urethroplasty.

PubMed

Maciejewski, Conrad C; Haines, Trevor; Rourke, Keith F

2017-05-01

To identify factors that predict patient satisfaction after urethroplasty by prospectively examining patient-reported quality of life scores using 3 validated instruments. A 3-part prospective survey consisting of the International Prostate Symptom Score (IPSS), the International Index of Erectile Function (IIEF) score, and a urethroplasty quality of life survey was completed by patients who underwent urethroplasty preoperatively and at 6 months postoperatively. The quality of life score included questions on genitourinary pain, urinary tract infection (UTI), postvoid dribbling, chordee, shortening, overall satisfaction, and overall health. Data were analyzed using descriptive statistics, paired t test, univariate and multivariate logistic regression analyses, and Wilcoxon signed-rank analysis. Patients were enrolled in the study from February 2011 to December 2014, and a total of 94 patients who underwent a total of 102 urethroplasties completed the study. Patients reported statistically significant improvements in IPSS (P < .001). Ordinal linear regression analysis revealed no association between age, IPSS, or IIEF score and patient satisfaction. Wilcoxon signed-rank analysis revealed significant improvements in pain scores (P = .02), UTI (P < .001), perceived overall health (P = .01), and satisfaction (P < .001). Univariate logistic regression identified a length >4 cm and the absence of UTI, pain, shortening, and chordee as predictors of patient satisfaction. Multivariate analysis of quality of life domain scores identified absence of shortening and absence of chordee as independent predictors of patient satisfaction following urethroplasty (P < .01). Patient voiding function and quality of life improve significantly following urethroplasty, but improvement in voiding function is not associated with patient satisfaction. Chordee status and perceived penile shortening impact patient satisfaction, and should be included in patient-reported outcome measures. Copyright © 2017 Elsevier Inc. All rights reserved.

Morphometric assessment of the red stripe weevils, Rhynchophorus vulneratus (Coleoptera: Curculionidae) from several localities in Malaysia

NASA Astrophysics Data System (ADS)

Sazali, Siti Nurlydia; Hazmi, Izfa Riza; Rahim, Faszly; Abang, Fatimah; Jemain, Abdul Aziz

2018-04-01

The recognition of intraspecific variation could enhance knowledge and understanding on the population divergence that might be resulted from different geographical areas. To study the possible effect derived from different locations, a morphometric study of the red stripe weevils, Rhynchophorus vulneratus from different localities in Malaysia was conducted using field and voucher specimens. A total of twenty-three morphological characters were examined from 108 individuals of R. vulneratus representing population of Kota Samarahan, Mukah and central of Peninsular Malaysia. The data were subjected to univariate one-way single factor analysis of variance (ANOVA) and analysed in factor analysis using SPSS version 22.0 software. Univariate ANOVA showed that all tested variables were significantly different (p<0.05) except for mesocoxal distance (MSD), meanwhile from the factor analysis, the first three factors with eigenvalues greater than 1.0 were successfully extracted, resulting in a high variation of 82.687%. For factor 1, 39.213% of total variation was recorded, factor 2 accounted for 34.096% and factor 3 contributing to 9.377%, respectively. The mixed plotting among the twenty-three morphological characters suggests a strong correlation among the parameters examined and further statistical analysis should be conducted to include environmental factors such as habitat types, food availability and predation effect.

Measuring the statistical validity of summary meta-analysis and meta-regression results for use in clinical practice.

PubMed

Willis, Brian H; Riley, Richard D

2017-09-20

An important question for clinicians appraising a meta-analysis is: are the findings likely to be valid in their own practice-does the reported effect accurately represent the effect that would occur in their own clinical population? To this end we advance the concept of statistical validity-where the parameter being estimated equals the corresponding parameter for a new independent study. Using a simple ('leave-one-out') cross-validation technique, we demonstrate how we may test meta-analysis estimates for statistical validity using a new validation statistic, Vn, and derive its distribution. We compare this with the usual approach of investigating heterogeneity in meta-analyses and demonstrate the link between statistical validity and homogeneity. Using a simulation study, the properties of Vn and the Q statistic are compared for univariate random effects meta-analysis and a tailored meta-regression model, where information from the setting (included as model covariates) is used to calibrate the summary estimate to the setting of application. Their properties are found to be similar when there are 50 studies or more, but for fewer studies Vn has greater power but a higher type 1 error rate than Q. The power and type 1 error rate of Vn are also shown to depend on the within-study variance, between-study variance, study sample size, and the number of studies in the meta-analysis. Finally, we apply Vn to two published meta-analyses and conclude that it usefully augments standard methods when deciding upon the likely validity of summary meta-analysis estimates in clinical practice. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

TATES: Efficient Multivariate Genotype-Phenotype Analysis for Genome-Wide Association Studies

PubMed Central

van der Sluis, Sophie; Posthuma, Danielle; Dolan, Conor V.

2013-01-01

To date, the genome-wide association study (GWAS) is the primary tool to identify genetic variants that cause phenotypic variation. As GWAS analyses are generally univariate in nature, multivariate phenotypic information is usually reduced to a single composite score. This practice often results in loss of statistical power to detect causal variants. Multivariate genotype–phenotype methods do exist but attain maximal power only in special circumstances. Here, we present a new multivariate method that we refer to as TATES (Trait-based Association Test that uses Extended Simes procedure), inspired by the GATES procedure proposed by Li et al (2011). For each component of a multivariate trait, TATES combines p-values obtained in standard univariate GWAS to acquire one trait-based p-value, while correcting for correlations between components. Extensive simulations, probing a wide variety of genotype–phenotype models, show that TATES's false positive rate is correct, and that TATES's statistical power to detect causal variants explaining 0.5% of the variance can be 2.5–9 times higher than the power of univariate tests based on composite scores and 1.5–2 times higher than the power of the standard MANOVA. Unlike other multivariate methods, TATES detects both genetic variants that are common to multiple phenotypes and genetic variants that are specific to a single phenotype, i.e. TATES provides a more complete view of the genetic architecture of complex traits. As the actual causal genotype–phenotype model is usually unknown and probably phenotypically and genetically complex, TATES, available as an open source program, constitutes a powerful new multivariate strategy that allows researchers to identify novel causal variants, while the complexity of traits is no longer a limiting factor. PMID:23359524

Angiogenesis and lymphangiogenesis as prognostic factors after therapy in patients with cervical cancer

PubMed Central

Makarewicz, Roman; Kopczyńska, Ewa; Marszałek, Andrzej; Goralewska, Alina; Kardymowicz, Hanna

2012-01-01

Aim of the study This retrospective study attempts to evaluate the influence of serum vascular endothelial growth factor C (VEGF-C), microvessel density (MVD) and lymphatic vessel density (LMVD) on the result of tumour treatment in women with cervical cancer. Material and methods The research was carried out in a group of 58 patients scheduled for brachytherapy for cervical cancer. All women were patients of the Department and University Hospital of Oncology and Brachytherapy, Collegium Medicum in Bydgoszcz of Nicolaus Copernicus University in Toruń. VEGF-C was determined by means of a quantitative sandwich enzyme immunoassay using a human antibody VEGF-C ELISA produced by Bender MedSystem, enzyme-linked immunosorbent detecting the activity of human VEGF-C in body fluids. The measure for the intensity of angiogenesis and lymphangiogenesis in immunohistochemical reactions is the number of blood vessels within the tumour. Statistical analysis was done using Statistica 6.0 software (StatSoft, Inc. 2001). The Cox proportional hazards model was used for univariate and multivariate analyses. Univariate analysis of overall survival was performed as outlined by Kaplan and Meier. In all statistical analyses p < 0.05 (marked red) was taken as significant. Results In 51 patients who showed up for follow-up examination, the influence of the factors of angiogenesis, lymphangiogenesis, patients’ age and the level of haemoglobin at the end of treatment were assessed. Selected variables, such as patients’ age, lymph vessel density (LMVD), microvessel density (MVD) and the level of haemoglobin (Hb) before treatment were analysed by means of Cox logical regression as potential prognostic factors for lymph node invasion. The observed differences were statistically significant for haemoglobin level before treatment and the platelet number after treatment. The study revealed the following prognostic factors: lymph node status, FIGO stage, and kind of treatment. No statistically significant influence of angiogenic and lymphangiogenic factors on the prognosis was found. Conclusion Angiogenic and lymphangiogenic factors have no value in predicting response to radiotherapy in cervical cancer patients. PMID:23788848

Method and data evaluation at NASA endocrine laboratory. [Skylab 3 experiments

NASA Technical Reports Server (NTRS)

Johnston, D. A.

1974-01-01

The biomedical data of the astronauts on Skylab 3 were analyzed to evaluate the univariate statistical methods for comparing endocrine series experiments in relation to other medical experiments. It was found that an information storage and retrieval system was needed to facilitate statistical analyses.

MANCOVA for one way classification with homogeneity of regression coefficient vectors

NASA Astrophysics Data System (ADS)

Mokesh Rayalu, G.; Ravisankar, J.; Mythili, G. Y.

2017-11-01

The MANOVA and MANCOVA are the extensions of the univariate ANOVA and ANCOVA techniques to multidimensional or vector valued observations. The assumption of a Gaussian distribution has been replaced with the Multivariate Gaussian distribution for the vectors data and residual term variables in the statistical models of these techniques. The objective of MANCOVA is to determine if there are statistically reliable mean differences that can be demonstrated between groups later modifying the newly created variable. When randomization assignment of samples or subjects to groups is not possible, multivariate analysis of covariance (MANCOVA) provides statistical matching of groups by adjusting dependent variables as if all subjects scored the same on the covariates. In this research article, an extension has been made to the MANCOVA technique with more number of covariates and homogeneity of regression coefficient vectors is also tested.

Analysis of vector wind change with respect to time for Cape Kennedy, Florida

NASA Technical Reports Server (NTRS)

Adelfang, S. I.

1978-01-01

Multivariate analysis was used to determine the joint distribution of the four variables represented by the components of the wind vector at an initial time and after a specified elapsed time is hypothesized to be quadravariate normal; the fourteen statistics of this distribution, calculated from 15 years of twice-daily rawinsonde data are presented by monthly reference periods for each month from 0 to 27 km. The hypotheses that the wind component changes with respect to time is univariate normal, that the joint distribution of wind component change with respect to time is univariate normal, that the joint distribution of wind component changes is bivariate normal, and that the modulus of vector wind change is Rayleigh are tested by comparison with observed distributions. Statistics of the conditional bivariate normal distributions of vector wind at a future time given the vector wind at an initial time are derived. Wind changes over time periods from 1 to 5 hours, calculated from Jimsphere data, are presented. Extension of the theoretical prediction (based on rawinsonde data) of wind component change standard deviation to time periods of 1 to 5 hours falls (with a few exceptions) within the 95 percentile confidence band of the population estimate obtained from the Jimsphere sample data. The joint distributions of wind change components, conditional wind components, and 1 km vector wind shear change components are illustrated by probability ellipses at the 95 percentile level.

Acceleration techniques in the univariate Lipschitz global optimization

NASA Astrophysics Data System (ADS)

Sergeyev, Yaroslav D.; Kvasov, Dmitri E.; Mukhametzhanov, Marat S.; De Franco, Angela

2016-10-01

Univariate box-constrained Lipschitz global optimization problems are considered in this contribution. Geometric and information statistical approaches are presented. The novel powerful local tuning and local improvement techniques are described in the contribution as well as the traditional ways to estimate the Lipschitz constant. The advantages of the presented local tuning and local improvement techniques are demonstrated using the operational characteristics approach for comparing deterministic global optimization algorithms on the class of 100 widely used test functions.

Metabolomics analysis of follicular fluid in women with ovarian endometriosis undergoing in vitro fertilization.

PubMed

Karaer, Abdullah; Tuncay, Gorkem; Mumcu, Akın; Dogan, Berat

2018-05-28

The purpose of this study was to investigate whether a change in the follicular fluid metabolomics profile due to endometrioma is identifiable. Twelve women with ovarian endometriosis (aged<40 years, with a body mass index [BMI] of <30 kg/m 2 ) and 12 age- and BMI-matched controls (women with infertility purely due to a male factor) underwent ovarian stimulation for intracytoplasmic sperm injection (ICSI). Follicular fluid samples were collected from both of groups at the time of oocyte retrieval for ICSI. Next, nuclear magnetic resonance (NMR) spectroscopy was performed for the collected follicular fluids. The metabolic compositions of the follicular fluids were then compared using univariate and multivariate statistical analyses of NMR data. Univariate and multivariate statistical analyses of NMR data showed that the metabolomic profiles of the follicular fluids obtained from the women with ovarian endometriosis were distinctly different from those obtained from the control group. In comparison with the controls, the follicular fluids of the women with ovarian endometriosis had statistically significant elevated levels of lactate, β-glucose, pyruvate, and valine. We conclude that the levels of lactate, β-glucose, pyruvate, and valine in the follicular fluid of the women with endometrioma were higher than those of the controls. ASRM: American Society for Reproductive Medicine; BMI: body mass index; CPMG: Carr-Purcell-Meiboom-Gill; E 2 : estradiol; ESHRE: European Society of Human Reproduction and Embryology; ERETIC: electronic to access in vivo concentration; FF: follicular fluid; FSH: follicle-stimulating hormone; hCG: human chorionic gonadotropin; HEPES: 2-hydroxyethyl-1-piperazineethanesulfonic acid; ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilization; NMR: nuclear magnetic resonance spectroscopy; PCA: principal component analysis; PCOS: polycystic ovary syndrome; PLS-DA: partial least squares discriminant analysis; ppm: parts per million; PULCON: pulse length-based concentration determination; TSP: 3-(trimethylsilyl)-1-propanesulfonic acid sodium salt; VIP: variable importance in projection.

Resection of Concomitant Hepatic and Extrahepatic Metastases from Colorectal Cancer - A Worthwhile Operation?

PubMed

Diaconescu, Andrei; Alexandrescu, Sorin; Ionel, Zenaida; Zlate, Cristian; Grigorie, Razvan; Brasoveanu, Vladislav; Hrehoret, Doina; Ciurea, Silviu; Botea, Florin; Tomescu, Dana; Droc, Gabriela; Croitoru, Adina; Herlea, Vlad; Boros, Mirela; Grasu, Mugur; Dumitru, Radu; Toma, Mihai; Ionescu, Mihnea; Vasilescu, Catalin; Popescu, Irinel

2017-01-01

Background: The benefit of hepatic resection in case of concomitant colorectal hepatic and extrahepatic metastases (CHEHMs) is still debatable. The purpose of this study is to assess the results of resection of hepatic and extrahepatic metastases in patients with CHEHMs in a high-volume center for both hepatobiliary and colorectal surgery and to identify prognostic factors that correlate with longer survival in these patients. It was performed a retrospective analysis of 678 consecutive patients with liver resection for colorectal cancer metastases operated in a single Centre between April 1996 and March 2016. Among these, 73 patients presented CHEHMs. Univariate analysis was performed to identify the risk factors for overall survival (OS) in these patients. Results: There were 20 CHMs located at the lymphatic node level, 20 at the peritoneal level, 12 at the ovary and lung level, 12 presenting as local relapses and 9 other sites. 53 curative resections (R0) were performed. The difference in overall survival between the CHEHMs group and the CHMs group is statistically significant for the entire groups (p 0.0001), as well as in patients who underwent R0 resection (p 0.0001). In CHEHMs group, the OS was statistically significant higher in patients who underwent R0 resection vs. those with R1/R2 resection (p=0.004). Three variables were identified as prognostic factors for poor OS following univariate analysis: 4 or more hepatic metastases, major hepatectomy and the performance of operation during first period of the study (1996 - 2004). There was a tendency toward better OS in patients with ovarian or pulmonary location of extrahepatic disease, although the difference was not statistically significant. In patients with concomitant hepatic and extrahepatic metastases, complete resection of metastatic burden significantly prolong survival. The patients with up to 4 liver metastases, resectable by minor hepatectomy benefit the most from this aggressive onco-surgical management. Celsius.

What Do Differences Between Multi-voxel and Univariate Analysis Mean? How Subject-, Voxel-, and Trial-level Variance Impact fMRI Analysis

PubMed Central

Davis, Tyler; LaRocque, Karen F.; Mumford, Jeanette; Norman, Kenneth A.; Wagner, Anthony D.; Poldrack, Russell A.

2014-01-01

Multi-voxel pattern analysis (MVPA) has led to major changes in how fMRI data are analyzed and interpreted. Many studies now report both MVPA results and results from standard univariate voxel-wise analysis, often with the goal of drawing different conclusions from each. Because MVPA results can be sensitive to latent multidimensional representations and processes whereas univariate voxel-wise analysis cannot, one conclusion that is often drawn when MVPA and univariate results differ is that the activation patterns underlying MVPA results contain a multidimensional code. In the current study, we conducted simulations to formally test this assumption. Our findings reveal that MVPA tests are sensitive to the magnitude of voxel-level variability in the effect of a condition within subjects, even when the same linear relationship is coded in all voxels. We also find that MVPA is insensitive to subject-level variability in mean activation across an ROI, which is the primary variance component of interest in many standard univariate tests. Together, these results illustrate that differences between MVPA and univariate tests do not afford conclusions about the nature or dimensionality of the neural code. Instead, targeted tests of the informational content and/or dimensionality of activation patterns are critical for drawing strong conclusions about the representational codes that are indicated by significant MVPA results. PMID:24768930

Neural Activity Patterns in the Human Brain Reflect Tactile Stickiness Perception.

PubMed

Kim, Junsuk; Yeon, Jiwon; Ryu, Jaekyun; Park, Jang-Yeon; Chung, Soon-Cheol; Kim, Sung-Phil

2017-01-01

Our previous human fMRI study found brain activations correlated with tactile stickiness perception using the uni-variate general linear model (GLM) (Yeon et al., 2017). Here, we conducted an in-depth investigation on neural correlates of sticky sensations by employing a multivoxel pattern analysis (MVPA) on the same dataset. In particular, we statistically compared multi-variate neural activities in response to the three groups of sticky stimuli: A supra-threshold group including a set of sticky stimuli that evoked vivid sticky perception; an infra-threshold group including another set of sticky stimuli that barely evoked sticky perception; and a sham group including acrylic stimuli with no physically sticky property. Searchlight MVPAs were performed to search for local activity patterns carrying neural information of stickiness perception. Similar to the uni-variate GLM results, significant multi-variate neural activity patterns were identified in postcentral gyrus, subcortical (basal ganglia and thalamus), and insula areas (insula and adjacent areas). Moreover, MVPAs revealed that activity patterns in posterior parietal cortex discriminated the perceptual intensities of stickiness, which was not present in the uni-variate analysis. Next, we applied a principal component analysis (PCA) to the voxel response patterns within identified clusters so as to find low-dimensional neural representations of stickiness intensities. Follow-up clustering analyses clearly showed separate neural grouping configurations between the Supra- and Infra-threshold groups. Interestingly, this neural categorization was in line with the perceptual grouping pattern obtained from the psychophysical data. Our findings thus suggest that different stickiness intensities would elicit distinct neural activity patterns in the human brain and may provide a neural basis for the perception and categorization of tactile stickiness.

Neural Activity Patterns in the Human Brain Reflect Tactile Stickiness Perception

PubMed Central

Kim, Junsuk; Yeon, Jiwon; Ryu, Jaekyun; Park, Jang-Yeon; Chung, Soon-Cheol; Kim, Sung-Phil

2017-01-01

Our previous human fMRI study found brain activations correlated with tactile stickiness perception using the uni-variate general linear model (GLM) (Yeon et al., 2017). Here, we conducted an in-depth investigation on neural correlates of sticky sensations by employing a multivoxel pattern analysis (MVPA) on the same dataset. In particular, we statistically compared multi-variate neural activities in response to the three groups of sticky stimuli: A supra-threshold group including a set of sticky stimuli that evoked vivid sticky perception; an infra-threshold group including another set of sticky stimuli that barely evoked sticky perception; and a sham group including acrylic stimuli with no physically sticky property. Searchlight MVPAs were performed to search for local activity patterns carrying neural information of stickiness perception. Similar to the uni-variate GLM results, significant multi-variate neural activity patterns were identified in postcentral gyrus, subcortical (basal ganglia and thalamus), and insula areas (insula and adjacent areas). Moreover, MVPAs revealed that activity patterns in posterior parietal cortex discriminated the perceptual intensities of stickiness, which was not present in the uni-variate analysis. Next, we applied a principal component analysis (PCA) to the voxel response patterns within identified clusters so as to find low-dimensional neural representations of stickiness intensities. Follow-up clustering analyses clearly showed separate neural grouping configurations between the Supra- and Infra-threshold groups. Interestingly, this neural categorization was in line with the perceptual grouping pattern obtained from the psychophysical data. Our findings thus suggest that different stickiness intensities would elicit distinct neural activity patterns in the human brain and may provide a neural basis for the perception and categorization of tactile stickiness. PMID:28936171

Role of Adjuvant Chemoradiation Therapy in Adenocarcinomas of the Ampulla of Vater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, Sunil; Rana, Vishal; Evans, Douglas B.

2008-03-01

Purpose: The role of adjuvant chemoradiation therapy (CRT) in the treatment of ampullary cancers remains undefined. We retrospectively compared treatment outcomes in patients treated with pancreaticoduodenectomy alone versus those who received additional adjuvant CRT. Methods and Materials: Between May 1990 and January 2006, 54 of 96 patients with ampullary adenocarcinoma who underwent potentially curative pancreaticoduodenectomy also received adjuvant CRT. The median preoperative radiation dose was 45 Gy (range, 30-50.4 Gy) and median postoperative dose was 50.4 Gy (range, 45-55.8 Gy). Concurrent chemotherapy included primarily 5-fluorouracil (52%) and capecitabine (43%). Median follow-up was 31 months. Univariate and multivariate statistical methodologies weremore » used to determine significant prognostic factors for local control (LC), distant control (DC), and overall survival (OS). Results: Actuarial 5-year LC, DC, and OS were 77%, 69%, and 64%, respectively. On univariate analysis, age, gender, race/ethnicity, tumor grade, use of adjuvant treatment, and sequencing of adjuvant therapy were not significantly associated with LC, DC, or OS. However, on univariate analysis, T3/T4 tumor stage was prognostic for poorer LC and OS (p = 0.02 and p < 0.001, respectively); node-positive disease was prognostic for poorer LC (p = 0.03). On multivariate analysis, T3/T4 tumor stage was independently prognostic for decreased OS (p = 0.002). Among these patients (n = 34), those who received adjuvant CRT had a trend toward improved OS (median, 35.2 vs. 16.5 months; p = 0.06). Conclusions: Ampullary cancers have a distinctly better treatment outcome than pancreatic adenocarcinomas. Higher primary tumor stage (T3/T4), an independent adverse risk factor for poorer treatment outcomes, may warrant the addition of adjuvant CRT to pancreaticoduodenectomy.« less

Discerning mild cognitive impairment and Alzheimer Disease from normal aging: morphologic characterization based on univariate and multivariate models.

PubMed

Liao, Weiqi; Long, Xiaojing; Jiang, Chunxiang; Diao, Yanjun; Liu, Xin; Zheng, Hairong; Zhang, Lijuan

2014-05-01

Differentiating mild cognitive impairment (MCI) and Alzheimer Disease (AD) from healthy aging remains challenging. This study aimed to explore the cerebral structural alterations of subjects with MCI or AD as compared to healthy elderly based on the individual and collective effects of cerebral morphologic indices using univariate and multivariate analyses. T1-weighted images (T1WIs) were retrieved from Alzheimer Disease Neuroimaging Initiative database for 116 subjects who were categorized into groups of healthy aging, MCI, and AD. Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) were performed to explore the intergroup morphologic alterations indexed by surface area, curvature index, cortical thickness, and subjacent white matter volume with age and sex controlled as covariates, in 34 parcellated gyri regions of interest (ROIs) for both cerebral hemispheres based on the T1WI. Statistical parameters were mapped on the anatomic images to facilitate visual inspection. Global rather than region-specific structural alterations were revealed in groups of MCI and AD relative to healthy elderly using MANCOVA. ANCOVA revealed that the cortical thickness decreased more prominently in entorhinal, temporal, and cingulate cortices and was positively correlated with patients' cognitive performance in AD group but not in MCI. The temporal lobe features marked atrophy of white matter during the disease dynamics. Significant intercorrelations were observed among the morphologic indices with univariate analysis for given ROIs. Significant global structural alterations were identified in MCI and AD based on MANCOVA model with improved sensitivity. The intercorrelation among the morphologic indices may dampen the use of individual morphological parameter in featuring cerebral structural alterations. Decrease in cortical thickness is not reflective of the cognitive performance at the early stage of AD. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Measuring the statistical validity of summary meta‐analysis and meta‐regression results for use in clinical practice

PubMed Central

Riley, Richard D.

2017-01-01

An important question for clinicians appraising a meta‐analysis is: are the findings likely to be valid in their own practice—does the reported effect accurately represent the effect that would occur in their own clinical population? To this end we advance the concept of statistical validity—where the parameter being estimated equals the corresponding parameter for a new independent study. Using a simple (‘leave‐one‐out’) cross‐validation technique, we demonstrate how we may test meta‐analysis estimates for statistical validity using a new validation statistic, Vn, and derive its distribution. We compare this with the usual approach of investigating heterogeneity in meta‐analyses and demonstrate the link between statistical validity and homogeneity. Using a simulation study, the properties of Vn and the Q statistic are compared for univariate random effects meta‐analysis and a tailored meta‐regression model, where information from the setting (included as model covariates) is used to calibrate the summary estimate to the setting of application. Their properties are found to be similar when there are 50 studies or more, but for fewer studies Vn has greater power but a higher type 1 error rate than Q. The power and type 1 error rate of Vn are also shown to depend on the within‐study variance, between‐study variance, study sample size, and the number of studies in the meta‐analysis. Finally, we apply Vn to two published meta‐analyses and conclude that it usefully augments standard methods when deciding upon the likely validity of summary meta‐analysis estimates in clinical practice. © 2017 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:28620945

Prolonged instability prior to a regime shift

USGS Publications Warehouse

Spanbauer, Trisha; Allen, Craig R.; Angeler, David G.; Eason, Tarsha; Fritz, Sherilyn C.; Garmestani, Ahjond S.; Nash, Kirsty L.; Stone, Jeffery R.

2014-01-01

Regime shifts are generally defined as the point of ‘abrupt’ change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia.

Parasites as valuable stock markers for fisheries in Australasia, East Asia and the Pacific Islands.

PubMed

Lester, R J G; Moore, B R

2015-01-01

Over 30 studies in Australasia, East Asia and the Pacific Islands region have collected and analysed parasite data to determine the ranges of individual fish, many leading to conclusions about stock delineation. Parasites used as biological tags have included both those known to have long residence times in the fish and those thought to be relatively transient. In many cases the parasitological conclusions have been supported by other methods especially analysis of the chemical constituents of otoliths, and to a lesser extent, genetic data. In analysing parasite data, authors have applied multiple different statistical methodologies, including summary statistics, and univariate and multivariate approaches. Recently, a growing number of researchers have found non-parametric methods, such as analysis of similarities and cluster analysis, to be valuable. Future studies into the residence times, life cycles and geographical distributions of parasites together with more robust analytical methods will yield much important information to clarify stock structures in the area.

TGFbeta1 (Leu10Pro), p53 (Arg72Pro) can predict for increased risk for breast cancer in south Indian women and TGFbeta1 Pro (Leu10Pro) allele predicts response to neo-adjuvant chemo-radiotherapy.

PubMed

Rajkumar, Thangarajan; Samson, Mani; Rama, Ranganathan; Sridevi, Veluswami; Mahji, Urmila; Swaminathan, Rajaraman; Nancy, Nirmala K

2008-11-01

The breast cancer incidence has been increasing in the south Indian women. A case (n=250)-control (n=500) study was undertaken to investigate the role of Single Nucleotide Polymorphisms (SNP's) in GSTM1 (Present/Null); GSTP1 (Ile105Val), p53 (Arg72Pro), TGFbeta1 (Leu10Pro), c-erbB2 (Ile655Val), and GSTT1 (Null/Present) in breast cancer. In addition, the value of the SNP's in predicting primary tumor's pathologic response following neo-adjuvant chemo-radiotherapy was assessed. Genotyping was done using PCR (GSTM1, GSTT1), Taqman Allelic discrimination assay (GSTP1, c-erbB2) and PCR-CTPP (p53 and TGFbeta1). None of the gene SNP's studied were associated with a statistically significant increased risk for the breast cancer. However, combined analysis of the SNP's showed that p53 (Arg/Arg and Arg/Pro) with TGFbeta1 (Pro/Pro and Leu/Pro) were associated with greater than 2 fold increased risk for breast cancer in Univariate (P=0.01) and Multivariate (P=0.003) analysis. There was no statistically significant association for the GST family members with the breast cancer risk. TGFbeta1 (Pro/Pro) allele was found to predict complete pathologic response in the primary tumour following neo-adjuvant chemo-radiotherapy (OR=6.53 and 10.53 in Univariate and Multivariate analysis respectively) (P=0.004) and was independent of stage. This study suggests that SNP's can help predict breast cancer risk in south Indian women and that TGFbeta1 (Pro/Pro) allele is associated with a better pCR in the primary tumour.

Reversed inverse regression for the univariate linear calibration and its statistical properties derived using a new methodology

NASA Astrophysics Data System (ADS)

Kang, Pilsang; Koo, Changhoi; Roh, Hokyu

2017-11-01

Since simple linear regression theory was established at the beginning of the 1900s, it has been used in a variety of fields. Unfortunately, it cannot be used directly for calibration. In practical calibrations, the observed measurements (the inputs) are subject to errors, and hence they vary, thus violating the assumption that the inputs are fixed. Therefore, in the case of calibration, the regression line fitted using the method of least squares is not consistent with the statistical properties of simple linear regression as already established based on this assumption. To resolve this problem, "classical regression" and "inverse regression" have been proposed. However, they do not completely resolve the problem. As a fundamental solution, we introduce "reversed inverse regression" along with a new methodology for deriving its statistical properties. In this study, the statistical properties of this regression are derived using the "error propagation rule" and the "method of simultaneous error equations" and are compared with those of the existing regression approaches. The accuracy of the statistical properties thus derived is investigated in a simulation study. We conclude that the newly proposed regression and methodology constitute the complete regression approach for univariate linear calibrations.

Effect of mixed mutans streptococci colonization on caries development.

PubMed

Seki, M; Yamashita, Y; Shibata, Y; Torigoe, H; Tsuda, H; Maeno, M

2006-02-01

To evaluate the clinical importance of mixed mutans streptococci colonization in predicting caries in preschool children. Caries prevalence was examined twice, with a 6-month interval, in 410 preschool children aged 3-4 years at baseline. A commercial strip method was used to evaluate the mutans streptococci score in plaque collected from eight selected interdental spaces and in saliva. Mutans streptococci typing polymerase chain reaction (PCR) assays (Streptococcus sobrinus and Streptococcus mutans, including serotypes c, e, and f) were performed using colonies on the strips as template. Twenty variables were examined in a univariate analysis to predict caries development: questionnaire variables, results of clinical examination, mutans streptococci scores, and PCR detection of S. sobrinus and S. mutans (including serotypes c, e, and f). Sixteen variables showed statistically significant associations (P < 0.04) in the univariate analysis. However, when entered into a logistic regression, only five variables remained significant (P < 0.05): caries experience at baseline; mixed colonization of S. sobrinus and S. mutans including S. mutans serotypes; high plaque mutans streptococci score; habitual use of sweet drinks; and nonuse of fluoride toothpaste. 'Mixed mutans streptococci colonization' is a novel measure correlated with caries development in their primary dentition.

Expression of thymidylate synthase (TS) and its prognostic significance in patients with cutaneous angiosarcoma.

PubMed

Shimizu, A; Kaira, K; Okubo, Y; Utsumi, D; Bolag, A; Yasuda, M; Takahashi, K; Ishikawa, O

2017-01-01

Cutaneous angiosarcoma (CA) is extremely rare, and little is known about the biological significance of possible biomarkers for chemotherapeutic agents. Thymidylate synthase (TS) is an attractive target for cancer treatment in various human neoplasms. It remains unclear whether the expression of TS is associated with the clinicopathological features of CA patients. The aim of this study was to elucidate the relationship between TS expression and the clinicopathological significance in CA patients. Fifty-one patients with CA were included in this study. TS expression and Ki-67 labeling index were examined using immunohistochemical analysis. TS was positively expressed in 39% (20/51) of CA patients. No statistically significant prognostic factor was identified as a predictor of overall survival (OS) for all patients by univariate analysis, whereas a significant prognostic variable for progression free survival (PFS) was found to be the clinical stage. In addition, both univariate and multivariate analyses confirmed that positive expression of TS was a significant predictor of worse PFS in CA patients of clinical stage 1. Positive TS expression in CA was identified as a significant predictor of worse outcome in patients of clinical stage 1.

Diagnosis of intrauterine growth restriction: comparison of ultrasound parameters.

PubMed

Ott, William J

2002-04-01

The objective of this study is an attempt to evaluate the best ultrasonic method of diagnosing intrauterine growth restriction (IUGR); a retrospective study of patients with singleton pregnancies who had been scanned at the author's institution within 2 weeks of their delivery was undertaken. Estimated fetal weight, abdominal circumference, head circumference/abdominal circumference ratio, abdominal circumference/femur length ratio, and umbilical artery S/D ratio were compared for accuracy in prediction IUGR in the neonate using both univariant and multivariant statistical analysis. Five hundred one (501) patients were analyzed. One hundred fourteen (114) neonates were classified as IUGR (22.8%). Doppler evaluation of the umbilical artery showed the best sensitivity while both abdominal circumference alone and estimated fetal weight showed similar specificity, positive and negative predictive value, and lowest false-positive and -negative results. Logistic regression analysis confirmed the univariant results and showed that, when used in combination, abdominal circumference and Doppler, or estimated fetal weight and Doppler resulted in the best predictive values. Either estimated fetal weight or abdominal circumference (alone) are accurate predictors of IUGR. Combined with Doppler studies of the umbilical artery either method will provide accurate evaluation of suspected IUGR.

Importance of Preserving Cross-correlation in developing Statistically Downscaled Climate Forcings and in estimating Land-surface Fluxes and States

NASA Astrophysics Data System (ADS)

Das Bhowmik, R.; Arumugam, S.

2015-12-01

Multivariate downscaling techniques exhibited superiority over univariate regression schemes in terms of preserving cross-correlations between multiple variables- precipitation and temperature - from GCMs. This study focuses on two aspects: (a) develop an analytical solutions on estimating biases in cross-correlations from univariate downscaling approaches and (b) quantify the uncertainty in land-surface states and fluxes due to biases in cross-correlations in downscaled climate forcings. Both these aspects are evaluated using climate forcings available from both historical climate simulations and CMIP5 hindcasts over the entire US. The analytical solution basically relates the univariate regression parameters, co-efficient of determination of regression and the co-variance ratio between GCM and downscaled values. The analytical solutions are compared with the downscaled univariate forcings by choosing the desired p-value (Type-1 error) in preserving the observed cross-correlation. . For quantifying the impacts of biases on cross-correlation on estimating streamflow and groundwater, we corrupt the downscaled climate forcings with different cross-correlation structure.

Multi-resolutional shape features via non-Euclidean wavelets: Applications to statistical analysis of cortical thickness

PubMed Central

Kim, Won Hwa; Singh, Vikas; Chung, Moo K.; Hinrichs, Chris; Pachauri, Deepti; Okonkwo, Ozioma C.; Johnson, Sterling C.

2014-01-01

Statistical analysis on arbitrary surface meshes such as the cortical surface is an important approach to understanding brain diseases such as Alzheimer’s disease (AD). Surface analysis may be able to identify specific cortical patterns that relate to certain disease characteristics or exhibit differences between groups. Our goal in this paper is to make group analysis of signals on surfaces more sensitive. To do this, we derive multi-scale shape descriptors that characterize the signal around each mesh vertex, i.e., its local context, at varying levels of resolution. In order to define such a shape descriptor, we make use of recent results from harmonic analysis that extend traditional continuous wavelet theory from the Euclidean to a non-Euclidean setting (i.e., a graph, mesh or network). Using this descriptor, we conduct experiments on two different datasets, the Alzheimer’s Disease NeuroImaging Initiative (ADNI) data and images acquired at the Wisconsin Alzheimer’s Disease Research Center (W-ADRC), focusing on individuals labeled as having Alzheimer’s disease (AD), mild cognitive impairment (MCI) and healthy controls. In particular, we contrast traditional univariate methods with our multi-resolution approach which show increased sensitivity and improved statistical power to detect a group-level effects. We also provide an open source implementation. PMID:24614060

Quantitative investigation of inappropriate regression model construction and the importance of medical statistics experts in observational medical research: a cross-sectional study.

PubMed

Nojima, Masanori; Tokunaga, Mutsumi; Nagamura, Fumitaka

2018-05-05

To investigate under what circumstances inappropriate use of 'multivariate analysis' is likely to occur and to identify the population that needs more support with medical statistics. The frequency of inappropriate regression model construction in multivariate analysis and related factors were investigated in observational medical research publications. The inappropriate algorithm of using only variables that were significant in univariate analysis was estimated to occur at 6.4% (95% CI 4.8% to 8.5%). This was observed in 1.1% of the publications with a medical statistics expert (hereinafter 'expert') as the first author, 3.5% if an expert was included as coauthor and in 12.2% if experts were not involved. In the publications where the number of cases was 50 or less and the study did not include experts, inappropriate algorithm usage was observed with a high proportion of 20.2%. The OR of the involvement of experts for this outcome was 0.28 (95% CI 0.15 to 0.53). A further, nation-level, analysis showed that the involvement of experts and the implementation of unfavourable multivariate analysis are associated at the nation-level analysis (R=-0.652). Based on the results of this study, the benefit of participation of medical statistics experts is obvious. Experts should be involved for proper confounding adjustment and interpretation of statistical models. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Link between perceived smoking behaviour at school and students smoking status: a large survey among Italian adolescents.

PubMed

Backhaus, I; D'Egidio, V; Grassucci, D; Gelardini, M; Ardizzone, C; La Torre, G

2017-10-01

To investigate a possible link between sociodemographic factors, the perception of smoking habits at school and smoking status of Italian adolescents attending secondary school. The study was a cross-sectional study. An anonymous online survey was employed to gather information on age, gender, smoking status and to examine the perception of smoking behaviour on the school premises. Chi-squared and Kruskal-Wallis tests were performed for the univariate analysis and logistic and multinomial regressions for the multivariate analysis. The statistical analyses included 1889 students. Univariate analysis showed significant differences concerning knowledge between smoker and non-smoker concerning the harmfulness of smoking (P < 0.001). According to the multivariate analysis smokers had a higher perception of teacher, principal or janitor smoking at school (odds ratio: 1.54 [95% confidence interval 1.26-1.89]). Students older than 19 years most often begin smoking because their friends smoke compared with younger students (adjusted odds ratio: 1.18 [95% confidence interval 0.48-2.89]). School environment and behaviour of role models play a crucial part in student smoking. To prevent and reduce youth tobacco smoking, not merely the presence of preventive measures is important but greater attention needs to be placed on the enforcement of smoking policies. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Nontargeted, Rapid Screening of Extra Virgin Olive Oil Products for Authenticity Using Near-Infrared Spectroscopy in Combination with Conformity Index and Multivariate Statistical Analyses.

PubMed

Karunathilaka, Sanjeewa R; Kia, Ali-Reza Fardin; Srigley, Cynthia; Chung, Jin Kyu; Mossoba, Magdi M

2016-10-01

A rapid tool for evaluating authenticity was developed and applied to the screening of extra virgin olive oil (EVOO) retail products by using Fourier-transform near infrared (FT-NIR) spectroscopy in combination with univariate and multivariate data analysis methods. Using disposable glass tubes, spectra for 62 reference EVOO, 10 edible oil adulterants, 20 blends consisting of EVOO spiked with adulterants, 88 retail EVOO products and other test samples were rapidly measured in the transmission mode without any sample preparation. The univariate conformity index (CI) and the multivariate supervised soft independent modeling of class analogy (SIMCA) classification tool were used to analyze the various olive oil products which were tested for authenticity against a library of reference EVOO. Better discrimination between the authentic EVOO and some commercial EVOO products was observed with SIMCA than with CI analysis. Approximately 61% of all EVOO commercial products were flagged by SIMCA analysis, suggesting that further analysis be performed to identify quality issues and/or potential adulterants. Due to its simplicity and speed, FT-NIR spectroscopy in combination with multivariate data analysis can be used as a complementary tool to conventional official methods of analysis to rapidly flag EVOO products that may not belong to the class of authentic EVOO. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Decoding auditory spatial and emotional information encoding using multivariate versus univariate techniques.

PubMed

Kryklywy, James H; Macpherson, Ewan A; Mitchell, Derek G V

2018-04-01

Emotion can have diverse effects on behaviour and perception, modulating function in some circumstances, and sometimes having little effect. Recently, it was identified that part of the heterogeneity of emotional effects could be due to a dissociable representation of emotion in dual pathway models of sensory processing. Our previous fMRI experiment using traditional univariate analyses showed that emotion modulated processing in the auditory 'what' but not 'where' processing pathway. The current study aims to further investigate this dissociation using a more recently emerging multi-voxel pattern analysis searchlight approach. While undergoing fMRI, participants localized sounds of varying emotional content. A searchlight multi-voxel pattern analysis was conducted to identify activity patterns predictive of sound location and/or emotion. Relative to the prior univariate analysis, MVPA indicated larger overlapping spatial and emotional representations of sound within early secondary regions associated with auditory localization. However, consistent with the univariate analysis, these two dimensions were increasingly segregated in late secondary and tertiary regions of the auditory processing streams. These results, while complimentary to our original univariate analyses, highlight the utility of multiple analytic approaches for neuroimaging, particularly for neural processes with known representations dependent on population coding.

SPReM: Sparse Projection Regression Model For High-dimensional Linear Regression *

PubMed Central

Sun, Qiang; Zhu, Hongtu; Liu, Yufeng; Ibrahim, Joseph G.

2014-01-01

The aim of this paper is to develop a sparse projection regression modeling (SPReM) framework to perform multivariate regression modeling with a large number of responses and a multivariate covariate of interest. We propose two novel heritability ratios to simultaneously perform dimension reduction, response selection, estimation, and testing, while explicitly accounting for correlations among multivariate responses. Our SPReM is devised to specifically address the low statistical power issue of many standard statistical approaches, such as the Hotelling’s T2 test statistic or a mass univariate analysis, for high-dimensional data. We formulate the estimation problem of SPREM as a novel sparse unit rank projection (SURP) problem and propose a fast optimization algorithm for SURP. Furthermore, we extend SURP to the sparse multi-rank projection (SMURP) by adopting a sequential SURP approximation. Theoretically, we have systematically investigated the convergence properties of SURP and the convergence rate of SURP estimates. Our simulation results and real data analysis have shown that SPReM out-performs other state-of-the-art methods. PMID:26527844

Multivariate analysis for stormwater quality characteristics identification from different urban surface types in macau.

PubMed

Huang, J; Du, P; Ao, C; Ho, M; Lei, M; Zhao, D; Wang, Z

2007-12-01

Statistical analysis of stormwater runoff data enables general identification of runoff characteristics. Six catchments with different urban surface type including roofs, roadway, park, and residential/commercial in Macau were selected for sampling and study during the period from June 2005 to September 2006. Based on univariate statistical analysis of data sampled, major pollutants discharged from different urban surface type were identified. As for iron roof runoff, Zn is the most significant pollutant. The major pollutants from urban roadway runoff are TSS and COD. Stormwater runoff from commercial/residential and Park catchments show high level of COD, TN, and TP concentration. Principal component analysis was further done for identification of linkages between stormwater quality and urban surface types. Two potential pollution sources were identified for study catchments with different urban surface types. The first one is referred as nutrients losses, soil losses and organic pollutants discharges, the second is related to heavy metals losses. PCA was proved to be a viable tool to explain the type of pollution sources and its mechanism for different urban surface type catchments.

A comparison between univariate probabilistic and multivariate (logistic regression) methods for landslide susceptibility analysis: the example of the Febbraro valley (Northern Alps, Italy)

NASA Astrophysics Data System (ADS)

Rossi, M.; Apuani, T.; Felletti, F.

2009-04-01

The aim of this paper is to compare the results of two statistical methods for landslide susceptibility analysis: 1) univariate probabilistic method based on landslide susceptibility index, 2) multivariate method (logistic regression). The study area is the Febbraro valley, located in the central Italian Alps, where different types of metamorphic rocks croup out. On the eastern part of the studied basin a quaternary cover represented by colluvial and secondarily, by glacial deposits, is dominant. In this study 110 earth flows, mainly located toward NE portion of the catchment, were analyzed. They involve only the colluvial deposits and their extension mainly ranges from 36 to 3173 m2. Both statistical methods require to establish a spatial database, in which each landslide is described by several parameters that can be assigned using a main scarp central point of landslide. The spatial database is constructed using a Geographical Information System (GIS). Each landslide is described by several parameters corresponding to the value of main scarp central point of the landslide. Based on bibliographic review a total of 15 predisposing factors were utilized. The width of the intervals, in which the maps of the predisposing factors have to be reclassified, has been defined assuming constant intervals to: elevation (100 m), slope (5 °), solar radiation (0.1 MJ/cm2/year), profile curvature (1.2 1/m), tangential curvature (2.2 1/m), drainage density (0.5), lineament density (0.00126). For the other parameters have been used the results of the probability-probability plots analysis and the statistical indexes of landslides site. In particular slope length (0 ÷ 2, 2 ÷ 5, 5 ÷ 10, 10 ÷ 20, 20 ÷ 35, 35 ÷ 260), accumulation flow (0 ÷ 1, 1 ÷ 2, 2 ÷ 5, 5 ÷ 12, 12 ÷ 60, 60 ÷27265), Topographic Wetness Index 0 ÷ 0.74, 0.74 ÷ 1.94, 1.94 ÷ 2.62, 2.62 ÷ 3.48, 3.48 ÷ 6,00, 6.00 ÷ 9.44), Stream Power Index (0 ÷ 0.64, 0.64 ÷ 1.28, 1.28 ÷ 1.81, 1.81 ÷ 4.20, 4.20 ÷ 9.40). Geological map and land use map were also used, considering geological and land use properties as categorical variables. Appling the univariate probabilistic method the Landslide Susceptibility Index (LSI) is defined as the sum of the ratio Ra/Rb calculated for each predisposing factor, where Ra is the ratio between number of pixel of class and the total number of pixel of the study area, and Rb is the ratio between number of landslides respect to the pixel number of the interval area. From the analysis of the Ra/Rb ratio the relationship between landslide occurrence and predisposing factors were defined. Then the equation of LSI was used in GIS to trace the landslide susceptibility maps. The multivariate method for landslide susceptibility analysis, based on logistic regression, was performed starting from the density maps of the predisposing factors, calculated with the intervals defined above using the equation Rb/Rbtot, where Rbtot is a sum of all Rb values. Using stepwise forward algorithms the logistic regression was performed in two successive steps: first a univariate logistic regression is used to choose the most significant predisposing factors, then the multivariate logistic regression can be performed. The univariate regression highlighted the importance of the following factors: elevation, accumulation flow, drainage density, lineament density, geology and land use. When the multivariate regression was applied the number of controlling factors was reduced neglecting the geological properties. The resulting final susceptibility equation is: P = 1 / (1 + exp-(6.46-22.34*elevation-5.33*accumulation flow-7.99* drainage density-4.47*lineament density-17.31*land use)) and using this equation the susceptibility maps were obtained. To easy compare the results of the two methodologies, the susceptibility maps were reclassified in five susceptibility intervals (very high, high, moderate, low and very low) using natural breaks. Then the maps were validated using two cumulative distribution curves, one related to the landslides (number of landslides in each susceptibility class) and one to the basin (number of pixel covering each class). Comparing the curves for each method, it results that the two approaches (univariate and multivariate) are appropriate, providing acceptable results. In both maps the distribution of high susceptibility condition is mainly localized on the left slope of the catchment in agreement with the field evidences. The comparison between the methods was obtained by subtraction of the two maps. This operation shows that about 40% of the basin is classified by the same class of susceptibility. In general the univariate probabilistic method tends to overestimate the areal extension of the high susceptibility class with respect to the maps obtained by the logistic regression method.

Investigation of Clinical Characteristics and Etiological Factors in Children with Molar Incisor Hypomineralization

PubMed Central

Giuca, Maria Rita; Cappè, Maria; Carli, Elisabetta; Lardani, Lisa

2018-01-01

Aim The purpose of the present study was to evaluate the clinical defects and etiological factors potentially involved in the onset of MIH in a pediatric sample. Methods 120 children, selected from the university dental clinic, were included: 60 children (25 boys and 35 girls; average age: 9.8 ± 1.8 years) with MIH formed the test group and 60 children (27 boys and 33 girls; average age: 10.1 ± 2 years) without MIH constituted the control group. Distribution and severity of MIH defects were evaluated, and a questionnaire was used to investigate the etiological variables; chi-square, univariate, and multivariate statistical tests were performed (significance level set at p < 0.05). Results A total of 186 molars and 98 incisors exhibited MIH defects: 55 molars and 75 incisors showed mild defects, 91 molars and 20 incisors had moderate lesions, and 40 molars and 3 incisors showed severe lesions. Univariate and multivariate statistical analysis showed a significant association (p < 0.05) between MIH and ear, nose, and throat (ENT) disorders and the antibiotics used during pregnancy (0.019). Conclusions Moderate defects were more frequent in the molars, while mild lesions were more frequent in the incisors. Antibiotics used during pregnancy and ENT may be directly involved in the etiology of MIH in children. PMID:29861729

Quality control for quantitative PCR based on amplification compatibility test.

PubMed

Tichopad, Ales; Bar, Tzachi; Pecen, Ladislav; Kitchen, Robert R; Kubista, Mikael; Pfaffl, Michael W

2010-04-01

Quantitative qPCR is a routinely used method for the accurate quantification of nucleic acids. Yet it may generate erroneous results if the amplification process is obscured by inhibition or generation of aberrant side-products such as primer dimers. Several methods have been established to control for pre-processing performance that rely on the introduction of a co-amplified reference sequence, however there is currently no method to allow for reliable control of the amplification process without directly modifying the sample mix. Herein we present a statistical approach based on multivariate analysis of the amplification response data generated in real-time. The amplification trajectory in its most resolved and dynamic phase is fitted with a suitable model. Two parameters of this model, related to amplification efficiency, are then used for calculation of the Z-score statistics. Each studied sample is compared to a predefined reference set of reactions, typically calibration reactions. A probabilistic decision for each individual Z-score is then used to identify the majority of inhibited reactions in our experiments. We compare this approach to univariate methods using only the sample specific amplification efficiency as reporter of the compatibility. We demonstrate improved identification performance using the multivariate approach compared to the univariate approach. Finally we stress that the performance of the amplification compatibility test as a quality control procedure depends on the quality of the reference set. Copyright 2010 Elsevier Inc. All rights reserved.

Statistical interpretation of machine learning-based feature importance scores for biomarker discovery.

PubMed

Huynh-Thu, Vân Anh; Saeys, Yvan; Wehenkel, Louis; Geurts, Pierre

2012-07-01

Univariate statistical tests are widely used for biomarker discovery in bioinformatics. These procedures are simple, fast and their output is easily interpretable by biologists but they can only identify variables that provide a significant amount of information in isolation from the other variables. As biological processes are expected to involve complex interactions between variables, univariate methods thus potentially miss some informative biomarkers. Variable relevance scores provided by machine learning techniques, however, are potentially able to highlight multivariate interacting effects, but unlike the p-values returned by univariate tests, these relevance scores are usually not statistically interpretable. This lack of interpretability hampers the determination of a relevance threshold for extracting a feature subset from the rankings and also prevents the wide adoption of these methods by practicians. We evaluated several, existing and novel, procedures that extract relevant features from rankings derived from machine learning approaches. These procedures replace the relevance scores with measures that can be interpreted in a statistical way, such as p-values, false discovery rates, or family wise error rates, for which it is easier to determine a significance level. Experiments were performed on several artificial problems as well as on real microarray datasets. Although the methods differ in terms of computing times and the tradeoff, they achieve in terms of false positives and false negatives, some of them greatly help in the extraction of truly relevant biomarkers and should thus be of great practical interest for biologists and physicians. As a side conclusion, our experiments also clearly highlight that using model performance as a criterion for feature selection is often counter-productive. Python source codes of all tested methods, as well as the MATLAB scripts used for data simulation, can be found in the Supplementary Material.

A large-scale perspective on stress-induced alterations in resting-state networks

NASA Astrophysics Data System (ADS)

Maron-Katz, Adi; Vaisvaser, Sharon; Lin, Tamar; Hendler, Talma; Shamir, Ron

2016-02-01

Stress is known to induce large-scale neural modulations. However, its neural effect once the stressor is removed and how it relates to subjective experience are not fully understood. Here we used a statistically sound data-driven approach to investigate alterations in large-scale resting-state functional connectivity (rsFC) induced by acute social stress. We compared rsfMRI profiles of 57 healthy male subjects before and after stress induction. Using a parcellation-based univariate statistical analysis, we identified a large-scale rsFC change, involving 490 parcel-pairs. Aiming to characterize this change, we employed statistical enrichment analysis, identifying anatomic structures that were significantly interconnected by these pairs. This analysis revealed strengthening of thalamo-cortical connectivity and weakening of cross-hemispheral parieto-temporal connectivity. These alterations were further found to be associated with change in subjective stress reports. Integrating report-based information on stress sustainment 20 minutes post induction, revealed a single significant rsFC change between the right amygdala and the precuneus, which inversely correlated with the level of subjective recovery. Our study demonstrates the value of enrichment analysis for exploring large-scale network reorganization patterns, and provides new insight on stress-induced neural modulations and their relation to subjective experience.

Analysis of the dependence of extreme rainfalls

NASA Astrophysics Data System (ADS)

Padoan, Simone; Ancey, Christophe; Parlange, Marc

2010-05-01

The aim of spatial analysis is to quantitatively describe the behavior of environmental phenomena such as precipitation levels, wind speed or daily temperatures. A number of generic approaches to spatial modeling have been developed[1], but these are not necessarily ideal for handling extremal aspects given their focus on mean process levels. The areal modelling of the extremes of a natural process observed at points in space is important in environmental statistics; for example, understanding extremal spatial rainfall is crucial in flood protection. In light of recent concerns over climate change, the use of robust mathematical and statistical methods for such analyses has grown in importance. Multivariate extreme value models and the class of maxstable processes [2] have a similar asymptotic motivation to the univariate Generalized Extreme Value (GEV) distribution , but providing a general approach to modeling extreme processes incorporating temporal or spatial dependence. Statistical methods for max-stable processes and data analyses of practical problems are discussed by [3] and [4]. This work illustrates methods to the statistical modelling of spatial extremes and gives examples of their use by means of a real extremal data analysis of Switzerland precipitation levels. [1] Cressie, N. A. C. (1993). Statistics for Spatial Data. Wiley, New York. [2] de Haan, L and Ferreria A. (2006). Extreme Value Theory An Introduction. Springer, USA. [3] Padoan, S. A., Ribatet, M and Sisson, S. A. (2009). Likelihood-Based Inference for Max-Stable Processes. Journal of the American Statistical Association, Theory & Methods. In press. [4] Davison, A. C. and Gholamrezaee, M. (2009), Geostatistics of extremes. Journal of the Royal Statistical Society, Series B. To appear.

Radiographical findings in patients with liver cirrhosis and hepatic encephalopathy.

PubMed

Elwir, Saleh; Hal, Hassan; Veith, Joshua; Schreibman, Ian; Kadry, Zakiyah; Riley, Thomas

2016-08-01

Hepatic encephalopathy is a common complication encountered in patients with liver cirrhosis. Hepatic encephalopathy is not reflected in the current liver transplant allocation system. Correlation was sought between hepatic encephalopathy with findings detected on radiographic imaging studies and the patient's clinical profile. A retrospective analysis was conducted of patients with cirrhosis, who presented for liver transplant evaluation in 2009 and 2010. Patients with hepatocellular carcinoma, ejection fraction less than 60% and who had a TIPS (transjugular intrahepatic portosystemic shunting) procedure or who did not complete the evaluation were excluded. Statistical analysis was performed and variables found to be significant on univariate analysis (P < 0.05) were analysed by a multivariate logistic regression model. A total of 117 patients met the inclusion criteria and were divided into a hepatic encephalopathy group (n = 58) and a control group (n = 59). Univariate analysis found that a smaller portal vein diameter, smaller liver antero-posterior diameter, liver nodularity and use of diuretics or centrally acting medications showed significant correlation with hepatic encephalopathy. This association was confirmed for smaller portal vein, use of diuretics and centrally acting medications in the multivariate analysis. A decrease in portal vein diameter was associated with increased risk of encephalopathy. Identifying patients with smaller portal vein diameter may warrant screening for encephalopathy by more advanced psychometric testing, and more aggressive control of constipation and other factors that may precipitate encephalopathy. © The Author(s) 2015. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

Reflectance of vegetation, soil, and water

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1973-01-01

There are no author-identified significant results in this report. This report deals with the selection of the best channels from the 24-channel aircraft data to represent crop and soil conditions. A three-step procedure has been developed that involves using univariate statistics and an F-ratio test to indicate the best 14 channels. From the 14, the 10 best channels are selected by a multivariate stochastic process. The third step involves the pattern recognition procedures developed in the data analysis plan. Indications are that the procedures in use are satsifactory and will extract the desired information from the data.

Relevant Feature Set Estimation with a Knock-out Strategy and Random Forests

PubMed Central

Ganz, Melanie; Greve, Douglas N.; Fischl, Bruce; Konukoglu, Ender

2015-01-01

Group analysis of neuroimaging data is a vital tool for identifying anatomical and functional variations related to diseases as well as normal biological processes. The analyses are often performed on a large number of highly correlated measurements using a relatively smaller number of samples. Despite the correlation structure, the most widely used approach is to analyze the data using univariate methods followed by post-hoc corrections that try to account for the data’s multivariate nature. Although widely used, this approach may fail to recover from the adverse effects of the initial analysis when local effects are not strong. Multivariate pattern analysis (MVPA) is a powerful alternative to the univariate approach for identifying relevant variations. Jointly analyzing all the measures, MVPA techniques can detect global effects even when individual local effects are too weak to detect with univariate analysis. Current approaches are successful in identifying variations that yield highly predictive and compact models. However, they suffer from lessened sensitivity and instabilities in identification of relevant variations. Furthermore, current methods’ user-defined parameters are often unintuitive and difficult to determine. In this article, we propose a novel MVPA method for group analysis of high-dimensional data that overcomes the drawbacks of the current techniques. Our approach explicitly aims to identify all relevant variations using a “knock-out” strategy and the Random Forest algorithm. In evaluations with synthetic datasets the proposed method achieved substantially higher sensitivity and accuracy than the state-of-the-art MVPA methods, and outperformed the univariate approach when the effect size is low. In experiments with real datasets the proposed method identified regions beyond the univariate approach, while other MVPA methods failed to replicate the univariate results. More importantly, in a reproducibility study with the well-known ADNI dataset the proposed method yielded higher stability and power than the univariate approach. PMID:26272728

Time from Prior Chemotherapy Enhances Prognostic Risk Grouping in the Second-line Setting of Advanced Urothelial Carcinoma: A Retrospective Analysis of Pooled, Prospective Phase 2 Trials

PubMed Central

Sonpavde, Guru; Pond, Gregory R.; Fougeray, Ronan; Choueiri, Toni K.; Qu, Angela Q.; Vaughn, David J.; Niegisch, Guenter; Albers, Peter; James, Nicholas D.; Wong, Yu-Ning; Ko, Yoo-Joung; Sridhar, Srikala S.; Galsky, Matthew D.; Petrylak, Daniel P.; Vaishampayan, Ulka N.; Khan, Awais; Vogelzang, Nicholas J.; Beer, Tomasz M.; Stadler, Walter M.; O’Donnell, Peter H.; Sternberg, Cora N.; Rosenberg, Jonathan E.; Bellmunt, Joaquim

2014-01-01

Background Outcomes for patients in the second-line setting of advanced urothelial carcinoma (UC) are dismal. The recognized prognostic factors in this context are Eastern Cooperative Oncology Group (ECOG) performance status (PS) >0, hemoglobin level (Hb) <10 g/dl, and liver metastasis (LM). Objectives The purpose of this retrospective study of prospective trials was to investigate the prognostic value of time from prior chemotherapy (TFPC) independent of known prognostic factors. Design, setting, and participants: Data from patients from seven prospective trials with available baseline TFPC, Hb, PS, and LM values were used for retrospective analysis (n = 570). External validation was conducted in a second-line phase 3 trial comparing best supportive care (BSC) versus vinflunine plus BSC (n = 352). Outcome measurements and statistical analysis Cox proportional hazards regression was used to evaluate the association of factors, with overall survival (OS) and progression-free survival (PFS) being the respective primary and secondary outcome measures. Results and limitations ECOG-PS >0, LM, Hb <10 g/dl, and shorter TFPC were significant prognostic factors for OS and PFS on multivariable analysis. Patients with zero, one, two, and three to four factors demonstrated median OS of 12.2, 6.7, 5.1, and 3.0 mo, respectively (concordance statistic = 0.638). Setting of prior chemotherapy (metastatic disease vs perioperative) and prior platinum agent (cisplatin or carboplatin) were not prognostic factors. External validation demonstrated a significant association of TFPC with PFS on univariable and most multivariable analyses, and with OS on univariable analyses. Limitations of retrospective analyses are applicable. Conclusions Shorter TFPC enhances prognostic classification independent of ECOG-PS>0, Hb<10 g/ dl, and LM in the setting of second-line therapy for advanced UC. These data may facilitate drug development and interpretation of trials. PMID:23206856

Whole brain radiotherapy and stereotactic radiosurgery for patients with recursive partitioning analysis I and lesions <5 cm(3): A matched pair analysis.

PubMed

Viani, Gustavo Arruda; Godoi da Silva, Lucas Bernardes; Viana, Bruno Silveira; Rossi, Bruno Tiago; Suguikawa, Elton; Zuliani, Gisele

2016-01-01

The intention of this study is to compare whole brain radiotherapy and stereotactic radiosurgery (WBRT + SRS) with WBRT in patients with 1-4 brain metastases to find a subgroup of patients that have a great benefit with aggressive treatment. Between December 2002 and December 2013, 60 patients with 1-4 brain metastases were treated by WBRT + SRS. In this period, 60 patients treated with WBRT were matched with patients treated with WBRT + SRS. The median survival for the entire cohort was 8.3 months. In the univariate analysis, WBRT + SRS (0.031), the presence of extracranial disease (P = 0.02), Karnofsky performance score <70 (P = 0.0001), and age >65 (P = 0.001) years were significant factors for survival. In the entire cohort, the median survival for recursive partitioning analysis (RPA) classes I, II, and III was 11, 7, and 3 months, respectively (P = 0.0001). In a stratified analysis, only RPA class I achieved statistical significance for 1-year survival between the groups (WBRT + SRS = 51% and WBRT = 23%, P = 0.03). Cox regression analysis revealed WBRT + SRS, age >65 years, and extracranial disease as independent prognostic factors. In the univariate analysis, lesion volume ≤5 cm 3 (P = 0.002) and WBRT + SRS (P = 0.003) were the significant factors associated with better brain control. WBRT plus SRS was an independent prognostic factor for survival. However, the combined treatment appears to be justified only in patients with RPA I and lesion volume ≤5 cm 3, independently of the number of lesions.

Capillary loss on nailfold capillary microscopy is associated with mortality in systemic sclerosis.

PubMed

Pavan, Thais Rohde; Bredemeier, Markus; Hax, Vanessa; Capobianco, Karina Gatz; da Silva Mendonça Chakr, Rafael; Xavier, Ricardo Machado

2018-02-01

The objective of this study is to test the association of the severity of nailfold capillaroscopy (NFC) abnormalities with mortality in systemic sclerosis (SSc). One hundred and seventy SSc patients underwent an extensive evaluation (including high-resolution computed tomography, pulmonary function tests, and Doppler echocardiography) at baseline following a standard protocol. Capillary loss on NFC was evaluated using the avascular score (AS, ranging from 0 to 3), and the mean number of ectasias, megacapillaries, and hemorrhages per finger was also recorded. After a mean period of 10.1 ± 4.9 years, the life status of the patients was ascertained. Univariate and multivariate Cox proportional hazards models were used for statistical analysis. Overall, 73 patients died. By univariate Cox analysis, the AS was significantly associated with mortality (hazard ratio [HR] = 1.64, 95% CI 1.22 to 2.19, p = 0.001). In our study, this association was stronger than that of race, gender, anticentromere antibodies, anti-topoisomerase I antibodies, and form of disease and had similar strength to that of skin score in univariate analyses. However, after controlling for a combination of variables (age, skin score, gender, race, signs of peripheral ischemia, and extent of interstitial lung disease, all independently associated with mortality), the association of AS with mortality was blunted (HR = 1.15, 95% CI 0.80 to 1.65, p = 0.445). Other NFC variables were not related to mortality. AS was associated with higher risk of death and, despite not having an independent association with mortality after controlling for a set of demographic and clinical variables, may be a useful tool in prognostic evaluation of SSc.

Univariate Analysis of Multivariate Outcomes in Educational Psychology.

ERIC Educational Resources Information Center

Hubble, L. M.

1984-01-01

The author examined the prevalence of multiple operational definitions of outcome constructs and an estimate of the incidence of Type I error rates when univariate procedures were applied to multiple variables in educational psychology. Multiple operational definitions of constructs were advocated and wider use of multivariate analysis was…

Risk factors for hydrocephalus and neurological deficit in children born with an encephalocele.

PubMed

Da Silva, Stephanie L; Jeelani, Yasser; Dang, Ha; Krieger, Mark D; McComb, J Gordon

2015-04-01

There is a known association of hydrocephalus with encephaloceles. Risk factors for hydrocephalus and neurological deficit were ascertained in a series of patients born with an encephalocele. A retrospective analysis was undertaken of patients treated for encephaloceles at Children's Hospital Los Angeles between 1994 and 2012. The following factors were evaluated for their prognostic value: age at presentation, sex, location of encephalocele, size, contents, microcephaly, presence of hydrocephalus, CSF leak, associated cranial anomalies, and neurological outcome. Seventy children were identified, including 38 girls and 32 boys. The median age at presentation was 2 months. The mean follow-up duration was 3.7 years. Encephalocele location was classified as anterior (n = 14) or posterior (n = 56) to the coronal suture. The average maximum encephalocele diameter was 4 cm (range 0.5-23 cm). Forty-seven encephaloceles contained neural tissue. Eight infants presented at birth with CSF leaking from the encephalocele, with 1 being infected. Six patients presented with hydrocephalus, while 11 developed progressive hydrocephalus postoperatively. On univariate analysis, the presence of neural tissue, cranial anomalies, encephalocele size of at least 2 cm, seizure disorder, and microcephaly were each positively associated with hydrocephalus. On multivariate logistic regression modeling, the single prognostic factor for hydrocephalus of borderline statistical significance was the presence of neural tissue (odds ratio [OR] = 5.8, 95% confidence interval [CI] = 0.8-74.0). Fourteen patients had severe developmental delay, 28 had mild/moderate delay, and 28 were neurologically normal. On univariate analysis, the presence of cranial anomalies, larger size of encephalocele, hydrocephalus, and microcephaly were positively associated with neurological deficit. In the multivariable model, the only statistically significant prognostic factor for neurological deficit was presence of hydrocephalus (OR 17.2, 95% CI 1.7-infinity). In multivariate models, the presence of neural tissue was borderline significantly associated with hydrocephalus and the presence of hydrocephalus was significantly associated with neurological deficit. The location of the encephalocele did not have a statistically significant association with incidence of hydrocephalus or neurological deficit. In contrast to modestly good/fair neurological outcome in children with an encephalocele without hydrocephalus, the presence of hydrocephalus resulted in a far worse neurological outcome.

Comparative study of the efficiency of computed univariate and multivariate methods for the estimation of the binary mixture of clotrimazole and dexamethasone using two different spectral regions

NASA Astrophysics Data System (ADS)

Fayez, Yasmin Mohammed; Tawakkol, Shereen Mostafa; Fahmy, Nesma Mahmoud; Lotfy, Hayam Mahmoud; Shehata, Mostafa Abdel-Aty

2018-04-01

Three methods of analysis are conducted that need computational procedures by the Matlab® software. The first is the univariate mean centering method which eliminates the interfering signal of the one component at a selected wave length leaving the amplitude measured to represent the component of interest only. The other two multivariate methods named PLS and PCR depend on a large number of variables that lead to extraction of the maximum amount of information required to determine the component of interest in the presence of the other. Good accurate and precise results are obtained from the three methods for determining clotrimazole in the linearity range 1-12 μg/mL and 75-550 μg/mL with dexamethasone acetate 2-20 μg/mL in synthetic mixtures and pharmaceutical formulation using two different spectral regions 205-240 nm and 233-278 nm. The results obtained are compared statistically to each other and to the official methods.

Low vascularity predicts favourable outcomes in leiomyoma patients treated with uterine artery embolization.

PubMed

Tang, Yixin; Chen, Chunlin; Duan, Hui; Ma, Ben; Liu, Ping

2016-10-01

To investigate the clinical factors predicting outcomes of leiomyoma treated with uterine artery embolization (UAE). A total of 183 uterine leiomyoma patients undergoing UAE were retrospectively analyzed. Patient age, characteristics of vascular supply in magnetic resonance imaging (MRI)/digital subtraction angiography (DSA), number, size and location of leiomyoma were recorded. Leiomyoma regrowth, new leiomyoma appearance and recurrence of any previously reported symptoms were carefully monitored over a mean follow-up of 30 months (median 32 months, range 12-80). Potential recurrence risk factors were analyzed by univariate and multivariate cox regression analysis. Twenty-three recurrences were recorded. The difference in the vascularity classification systems between MRI and DSA was not statistically significant (P = 0.059). High vascularity in MRI, high vascularity in DSA and multiple leiomyoma showed a significant risk of recurrence using univariate and multivariate analysis (P = 0.004, P < 0.001 and P = 0.023, respectively). The other factors were not significantly associated with leiomyoma recurrence (P > 0.05). Low vascularity and solitary leiomyoma indicated favourable outcomes in patients treated with UAE. • Low vascularity and solitary mass predicted favourable outcomes in UAE-treated patients. • MRI might provide information on vascularity in leiomyoma before UAE. • Variations in vascular supply, age, size, location were not associated with recurrence.

EMMPRIN/CD147 is an independent prognostic biomarker in cutaneous melanoma.

PubMed

Caudron, Anne; Battistella, Maxime; Feugeas, Jean-Paul; Pages, Cécile; Basset-Seguin, Nicole; Mazouz Dorval, Sarra; Funck Brentano, Elisa; Sadoux, Aurélie; Podgorniak, Marie-Pierre; Menashi, Suzanne; Janin, Anne; Lebbé, Céleste; Mourah, Samia

2016-08-01

CD147 has been implicated in melanoma invasion and metastasis mainly through increasing metalloproteinase synthesis and regulating VEGF/VEGFR signalling. In this study, the prognostic value of CD147 expression was investigated in a cohort of 196 cutaneous melanomas including 136 consecutive primary malignant melanomas, 30 lymph nodes, 16 in-transit and 14 visceral metastases. A series of 10 normal skin, 10 blue nevi and 10 dermal nevi was used as control. CD147 expression was assessed by immunohistochemistry, and the association of its expression with the clinicopathological characteristics of patients and survival was evaluated using univariate and multivariate statistical analyses. Univariate analysis showed that high CD147 expression was significantly associated with metastatic potential and with a reduced overall survival (P < 0.05 for both) in primary melanoma patients. CD147 expression level was correlated with histological factors which were associated with prognosis: Clark level, ulceration status and more particularly with Breslow index (r = 0.7, P < 10(-8) ). Multivariate analysis retained CD147 expression level and ulceration status as predicting factors for metastasis and overall survival (P < 0.05 for both). CD147 emerges as an important factor in the aggressive behaviour of melanoma and deserves further evaluation as an independent prognostic biomarker. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Prognostic significance of MRI findings in patients with myxoid-round cell liposarcoma.

PubMed

Tateishi, Ukihide; Hasegawa, Tadashi; Beppu, Yasuo; Kawai, Akira; Satake, Mitsuo; Moriyama, Noriyuki

2004-03-01

The aims of this study were to determine the prognostic significance of MRI findings in patients with myxoid-round cell liposarcomas and to clarify which MRI features best indicate tumors with adverse clinical behavior. The initial MRI studies of 36 pathologically confirmed myxoid-round cell liposarcomas were retrospectively reviewed, and observations from this review were correlated with the histopathologic features. MR images were evaluated by two radiologists with agreement by consensus, and both univariate and multivariate analyses were conducted to evaluate survival with a median clinical follow-up of 33 months (range, 9-276 months). Statistically significant MRI findings that favored a diagnosis of intermediate- or high-grade tumor were large tumor size (> 10 cm), deeply situated tumor, tumor possessing irregular contours, absence of lobulation, absence of thin septa, presence of thick septa, absence of tumor capsule, high-intensity signal pattern, pronounced enhancement, and globular or nodular enhancement. Of these MRI findings, thin septa (p < 0.05), a tumor capsule (p < 0.01), and pronounced enhancement (p < 0.01) were associated significantly, according to univariate analysis, with overall survival. Multivariate analysis indicated that pronounced enhancement was associated significantly with overall survival (p < 0.05). Contrast-enhanced MRI findings can indicate a good or adverse prognosis in patients with myxoid-round cell liposarcomas.

Patients’ willingness to pay for cognitive pharmacist services in community pharmacies

PubMed Central

Lakić, Dragana; Stević, Ivana; Odalović, Marina; Vezmar-Kovačević, Sandra; Tadić, Ivana

2017-01-01

Aim To determine the general population willingness to pay for cognitive pharmacist service in community pharmacy, describe the behavior of participants regarding health care issues, and evaluate correlation between participants’ sociodemographic characteristics or attitudes and their willingness to pay. Methods A questionnaire-based survey was conducted among general population visiting community pharmacies. The participants were asked about receiving cognitive pharmacist services to identify and resolve potential medication therapy problems after the initiation of a new medicine to optimize health outcomes of the patients. A univariate and multivariate analysis were used to analyze associations between different variables and willingness to pay for pharmacy service. Results Of 444 respondents, 167 (38%) reported that they were willing to pay for a medication management service provided in the community pharmacy. Univariate analysis showed significant association between the willingness to pay for pharmacist-provided service and respondents’ socio-demographic factors, health-related characteristics, and behavior, dilemmas, or need for certain pharmacist-provided service. The logistic regression model was statistically significant (χ2 = 4.599, P < 0.001). Conclusions The respondents expressed their willingness to pay for cognitive pharmacist services, which has not been fully recognized within the health care system. In future, pharmacists should focus on practical implementation of the service and models of funding. PMID:29094815

Patients' willingness to pay for cognitive pharmacist services in community pharmacies.

PubMed

Lakić, Dragana; Stević, Ivana; Odalović, Marina; Vezmar-Kovačević, Sandra; Tadić, Ivana

2017-10-31

To determine the general population willingness to pay for cognitive pharmacist service in community pharmacy, describe the behavior of participants regarding health care issues, and evaluate correlation between participants' sociodemographic characteristics or attitudes and their willingness to pay. A questionnaire-based survey was conducted among general population visiting community pharmacies. The participants were asked about receiving cognitive pharmacist services to identify and resolve potential medication therapy problems after the initiation of a new medicine to optimize health outcomes of the patients. A univariate and multivariate analysis were used to analyze associations between different variables and willingness to pay for pharmacy service. Of 444 respondents, 167 (38%) reported that they were willing to pay for a medication management service provided in the community pharmacy. Univariate analysis showed significant association between the willingness to pay for pharmacist-provided service and respondents' socio-demographic factors, health-related characteristics, and behavior, dilemmas, or need for certain pharmacist-provided service. The logistic regression model was statistically significant (χ2=4.599, P<0.001). The respondents expressed their willingness to pay for cognitive pharmacist services, which has not been fully recognized within the health care system. In future, pharmacists should focus on practical implementation of the service and models of funding.

Prevalence of gestational diabetes mellitus in Europe: A meta-analysis.

PubMed

Eades, Claire E; Cameron, Dawn M; Evans, Josie M M

2017-07-01

Estimates of the prevalence of gestational diabetes vary widely. It is important to have a clear understanding of the prevalence of this condition to be able to plan interventions and health care provision. This paper describes a meta-analysis of primary research data reporting the prevalence of gestational diabetes mellitus in the general pregnant population of developed countries in Europe. Four electronic databases were systematically searched in May 2016. English language articles reporting gestational diabetes mellitus prevalence using universal screening in general pregnant population samples from developed countries in Europe were included. All papers identified by the search were screened by one author, and then half screened independently by a second author and half by a third author. Data were extracted by one author. Values for the measures of interest were combined using a random effects model and analysis of the effects of moderator variables was carried out. A total of 3258 abstracts were screened, with 40 studies included in the review. Overall prevalence of gestational diabetes mellitus was 5.4% (3.8-7.8). Maternal age, year of data collection, country, area of Europe, week of gestation at testing, and diagnostic criteria were found to have a significant univariate effect on GDM prevalence, and area, week of gestation at testing and year of data collection remained statistically significant in multivariate analysis. Quality category was significant in multivariate but not univariate analysis. This meta-analysis shows prevalence of GDM that is at the upper end of previous estimates in Europe. Copyright © 2017 Elsevier B.V. All rights reserved.

Artificial neural network models for prediction of cardiovascular autonomic dysfunction in general Chinese population

PubMed Central

2013-01-01

Background The present study aimed to develop an artificial neural network (ANN) based prediction model for cardiovascular autonomic (CA) dysfunction in the general population. Methods We analyzed a previous dataset based on a population sample consisted of 2,092 individuals aged 30–80 years. The prediction models were derived from an exploratory set using ANN analysis. Performances of these prediction models were evaluated in the validation set. Results Univariate analysis indicated that 14 risk factors showed statistically significant association with CA dysfunction (P < 0.05). The mean area under the receiver-operating curve was 0.762 (95% CI 0.732–0.793) for prediction model developed using ANN analysis. The mean sensitivity, specificity, positive and negative predictive values were similar in the prediction models was 0.751, 0.665, 0.330 and 0.924, respectively. All HL statistics were less than 15.0. Conclusion ANN is an effective tool for developing prediction models with high value for predicting CA dysfunction among the general population. PMID:23902963

Diagnostic performance of conventional MRI parameters and apparent diffusion coefficient values in differentiating between benign and malignant soft-tissue tumours.

PubMed

Song, Y; Yoon, Y C; Chong, Y; Seo, S W; Choi, Y-L; Sohn, I; Kim, M-J

2017-08-01

To compare the abilities of conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) in differentiating between benign and malignant soft-tissue tumours (STT). A total of 123 patients with STT who underwent 3 T MRI, including diffusion-weighted imaging (DWI), were retrospectively analysed using variate conventional MRI parameters, ADC mean and ADC min . For the all-STT group, the correlation between the malignant STT conventional MRI parameters, except deep compartment involvement, compared to those of benign STT were statistically significant with univariate analysis. Maximum diameter of the tumour (p=0.001; odds ratio [OR], 8.97) and ADC mean (p=0.020; OR, 4.30) were independent factors with multivariate analysis. For the non-myxoid non-haemosiderin STT group, signal heterogeneity on axial T1-weighted imaging (T1WI; p=0.017), ADC mean , and ADC min (p=0.001, p=0.001), showed significant differences with univariate analysis between malignancy and benignity. Signal heterogeneity in axial T1WI (p=0.025; OR, 12.64) and ADC mean (p=0.004; OR, 33.15) were independent factors with multivariate analysis. ADC values as well as conventional MRI parameters were useful in differentiating between benign and malignant STT. The ADC mean was the most powerful diagnostic parameter in non-myxoid non-haemosiderin STT. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Post-operative diffusion weighted imaging as a predictor of posterior fossa syndrome permanence in paediatric medulloblastoma.

PubMed

Chua, Felicia H Z; Thien, Ady; Ng, Lee Ping; Seow, Wan Tew; Low, David C Y; Chang, Kenneth T E; Lian, Derrick W Q; Loh, Eva; Low, Sharon Y Y

2017-03-01

Posterior fossa syndrome (PFS) is a serious complication faced by neurosurgeons and their patients, especially in paediatric medulloblastoma patients. The uncertain aetiology of PFS, myriad of cited risk factors and therapeutic challenges make this phenomenon an elusive entity. The primary objective of this study was to identify associative factors related to the development of PFS in medulloblastoma patient post-tumour resection. This is a retrospective study based at a single institution. Patient data and all related information were collected from the hospital records, in accordance to a list of possible risk factors associated with PFS. These included pre-operative tumour volume, hydrocephalus, age, gender, extent of resection, metastasis, ventriculoperitoneal shunt insertion, post-operative meningitis and radiological changes in MRI. Additional variables included molecular and histological subtypes of each patient's medulloblastoma tumour. Statistical analysis was employed to determine evidence of each variable's significance in PFS permanence. A total of 19 patients with appropriately complete data was identified. Initial univariate analysis did not show any statistical significance. However, multivariate analysis for MRI-specific changes reported bilateral DWI restricted diffusion changes involving both right and left sides of the surgical cavity was of statistical significance for PFS permanence. The authors performed a clinical study that evaluated possible risk factors for permanent PFS in paediatric medulloblastoma patients. Analysis of collated results found that post-operative DWI restriction in bilateral regions within the surgical cavity demonstrated statistical significance as a predictor of PFS permanence-a novel finding in the current literature.

Thyroid V50 Highly Predictive of Hypothyroidism in Head-and-Neck Cancer Patients Treated With Intensity-modulated Radiotherapy (IMRT).

PubMed

Sachdev, Sean; Refaat, Tamer; Bacchus, Ian D; Sathiaseelan, Vythialinga; Mittal, Bharat B

2017-08-01

Radiation-induced hypothyroidism affects a significant number of patients with head-and-neck squamous cell cancer (HNSCC). We examined detailed dosimetric and clinical parameters to better determine the risk of hypothyroidism in euthyroid HNSCC patients treated with intensity-modulated radiation therapy (IMRT). From 2006 to 2010, 75 clinically euthyroid patients with HNSCC were treated with sequential IMRT. The cohort included 59 men and 16 females with a median age of 55 years (range, 30 to 89 y) who were treated to a median dose of 70 Gy (range, 60 to 75 Gy) with concurrent chemotherapy in nearly all (95%) cases. Detailed thyroid dosimetric parameters including maximum dose, mean dose, and other parameters (eg, V50-percent volume receiving at least 50 Gy) were obtained. Freedom from hypothyroidism was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were conducted using Cox regression. After a median follow-up period of 50 months, 25 patients (33%) became hypothyroid. On univariate analysis, thyroid V50 was highly correlated with developing hypothyroidism (P=0.035). Other dosimetric paramaters including mean thyroid dose (P=0.11) and maximum thyroid dose (P=0.39) did not reach statistical significance. On multivariate analysis incorporating patient, tumor, and treatment variables, V50 remained highly statistically significant (P=0.037). Regardless of other factors, for V50>60%, the odds ratio of developing hypothyroidism was 6.76 (P=0.002). In HNSCC patients treated with IMRT, thyroid V50 highly predicts the risk of developing hypothyroidism. V50>60% puts patients at a significantly higher risk of becoming hypothyroid. This can be a useful dose constraint to consider during treatment planning.

Surgical Outcomes in Vedolizumab-Treated Patients with Ulcerative Colitis.

PubMed

Lightner, Amy L; McKenna, Nicholas P; Moncrief, Sara; Pemberton, John H; Raffals, Laura E; Mathis, Kellie L

2017-12-01

Surgical outcomes and pouch outcomes in the setting of vedolizumab remains poorly understood. We sought to determine the rate of 30-day postoperative surgical infectious complications and pouch-specific complications among patients with ulcerative colitis (UC) who received vedolizumab within 12 weeks of surgery. A retrospective chart review between 5/1/2014 and 12/31/2016 of all adult patients with UC who underwent an abdominal operation was performed. Patients with UC who received vedolizumab within 12 weeks of their abdominal operation were compared with patients with UC on anti-TNFα treatment. Eighty-eight patients received vedolizumab and 62 received anti-TNFα within 12 weeks of surgery. More vedolizumab-treated patients had superficial surgical site infections (P = 0.047) and mucocutaneous separation at the ileostomy (P = 0.047), but there was no difference in the overall surgical infectious complication rate, deep space SSI, 30-day hospital readmission or return to the operating room. On univariate analysis of SSI among patients with UC, exposure to vedolizumab was not a significant predictor of SSI (P = 0.27), but steroids were predictive of SSI on univariate (P = 0.02) and multivariable analysis (P = 0.02). After ileal pouch anal anastomosis, there was a higher rate of intra-abdominal abscesses (31.3% versus 5.9%) and mucocutaneous separation (18.8% versus 0%) in the vedolizumab group compared with the anti-TNFα group, but statistical significance was not reached. Vedolizumab patients had significantly increased rates of superficial SSI, but not overall infectious complications. Among ileal pouch anal anastomosis patients, peripouch abscess rates were increased among vedolizumab-treated patients, but this did not reach statistical significance. Vedolizumab seems safe in the perioperative period for patients with UC.

A 10-Year Retrospective Review of a Nonrandomized Cohort of 458 Patients Undergoing Radical Radiotherapy or Cystectomy in Yorkshire, UK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munro, Nicholas P., E-mail: nic@munron.plus.co; Sundaram, Subramnian K.; Weston, Philip

2010-05-01

Purpose: We have previously reported on the mortality, morbidity, and 5-year survival of 458 patients who underwent radical radiotherapy or surgery for invasive bladder cancer in Yorkshire from 1993 to 1996. We aim to present the 10-year outcomes of these patients and to reassess factors predicting survival. Methods and Materials: The Northern and Yorkshire Cancer Registry identified 458 patients whose cases were subjected to Kaplan-Meier all-cause survival analyses, and a retrospective casenote analysis was undertaken on 398 (87%) for univariate and multivariate Cox proportional hazards modeling. Additional proportional hazards regression modeling was used to assess the statistical significance of variablesmore » on overall survival. Results: The ratio of radiotherapy to cystectomy was 3:1. There was no significant difference in overall 10-year survival between those who underwent radiotherapy (22%) and radical cystectomy (24%). Univariate analyses suggested that female sex, performance status, hydronephrosis and clinical T stage, were associated with an inferior outcome at 10 years. Patient age, tumor grade, treatment delay, and caseload factors were not significant. Multivariate analysis models were created for 0-2 and 2-10 years after treatment. There were no significant differences in treatment for 0-2 years; however, after 2 years follow-up there was some evidence of increased survival for patients receiving surgery compared with radiotherapy (hazard ratio 0.66, 95% confidence interval: 0.44-1.01, p = 0.06). Conclusions: a 10-year minimum follow-up has rarely been reported after radical treatment for invasive bladder cancer. At 10 years, there was no statistical difference in all-cause survival between surgery and radiotherapy treatment modalities.« less

Telangiectatic osteosarcoma: a review of 87 cases.

PubMed

Angelini, Andrea; Mavrogenis, Andreas F; Trovarelli, Giulia; Ferrari, Stefano; Picci, Piero; Ruggieri, Pietro

2016-10-01

Telangiectatic osteosarcoma (TOS) is a rare subtype of osteosarcoma. We analyzed (1) oncologic outcome in a large homogeneous series and (2) the role of prognostic factors on prognosis, local recurrence and metastasis. Eighty-seven patients (47 males, 54 %) were retrospectively analyzed. All except 4 had extracompartmental disease, and ten patients had lung metastasis at diagnosis. Pathologic fracture was present in 27 cases (31 %). Seventy-eight patients were treated with neoadjuvant chemotherapy; nine had surgery as first treatment. Limb-salvage surgery was performed in 71 cases, amputation in 14, and rotationplasty in one. One patient died before surgery. Possible prognostic factors were statistically evaluated. Overall survival was 60.7 % at 10 years of follow-up. Fifty-one patients were disease-free (58.6 %), 2 were alive with disease (2.3 %), 31 died with disease (35.6 %), and 3 died of other causes (3.4 %). Ten local recurrences were observed (11 %). Twenty-five patients (29 %) developed lung (22) or bone (3) metastases. No statistical difference was found considering age, metastases at diagnosis, gender, pathologic fracture, tumor volume, compartmental status, number of neoadjuvant chemotherapy agents and treatment. Induced necrosis was significant at both univariate and multivariate analysis (p < 0.0001). TOS does not have a poor prognosis as previously reported in literature, with a survival of about 60 % at 10 years. Most of patients can be cured with neoadjuvant chemotherapy plus surgery (limb sparing surgery is possible and safe). Tumor response to chemotherapy as induced necrosis was the only significant prognostic factors on survival, even if small tumor volume at diagnosis correlates with better prognosis at univariate analysis. IV.

Interval between surgery and radiotherapy: effect on local control of soft tissue sarcoma.

PubMed

Ballo, Matthew T; Zagars, Gunar K; Cormier, Janice N; Hunt, Kelly K; Feig, Barry W; Patel, Shreyaskumar R; Pisters, Peter W T

2004-04-01

To evaluate the clinical significance of the interval between surgery and postoperative radiotherapy (RT) for patients with soft tissue sarcoma. The records of 799 patients who underwent postoperative RT for soft tissue sarcoma between 1960 and 2000 were retrospectively reviewed. Univariate and multivariate analyses were used to evaluate the potential impact of the timing of postoperative RT on the rate of local control (LC). The actuarial overall LC rate was 79% at 10 years and 78% at 15 years. Univariate analysis indicated that the factors associated with an inferior 10-year LC rate were positive resection margins (p <0.0001); treatment for recurrent disease (p <0.0001); primary location in the head and neck or deep trunk (p <0.0001); age >64 years (p <0.0001); histopathologic subtype of malignant fibrous histiocytoma, neurogenic sarcoma, or epithelioid sarcoma (p = 0.01); tumor size >10 cm (p = 0.02); postoperative radiation dose <64 Gy (p = 0.03); and high histologic grade (p = 0.05). On multivariate analysis, all these factors remained statistically significant, except for high histologic grade and large size. A delay between surgery and the start of RT of >30 days was associated with a decreased 10-year LC rate, but this association was not statistically significant (76% vs. 83%, p = 0.07). The potential association between RT delay and inferior LC could be explained by an imbalance in the distribution of other prognostic factors. The interval between surgery and RT did not significantly impact the 10-year LC rate. These findings indicate that an RT delay should not be viewed as an independent adverse factor for LC and that treatment intensification may not be necessary for patients in whom a treatment delay has already occurred.

Quality of Life Outcomes in Patients Living with Stoma

PubMed Central

Anaraki, Fakhrialsadat; Vafaie, Mohamad; Behboo, Roobic; Maghsoodi, Nakisa; Esmaeilpour, Sahar; Safaee, Azadeh

2012-01-01

Background: Despite efforts to maintain the intestinal tissue and treat gastrointestinal disease, a large number of patients undergo ostomy surgery each year. Using stoma reduces the patient's quality of life (QOL) greatly. Although there are approximately 3000 patients in Iran; there is little information about the impact of stoma on their QOL. Aims: The study aims to evaluate QOL of stoma patients using a special measurement tool. Settings and Design: This survey was a cross-sectional study that was conducted on 102 random samples of stoma patients. Materials and Methods: The City of Hope Quality of Life-Ostomy Questionnaire was used for collecting demographic and clinical information and evaluating QOL. Statistical Analysis Used: Univariate and multiple regression analyses were performed to identify predictors of QOL. Results: The mean score for the overall QOL for stoma patients was 7.48 ± 0.9. 70% of patients were dissatisfied with sexual activities. More than half of them reported feelings of depression following stoma surgery. Univariate analysis indicated that factors such as the type of ostomy (temporary/permanent), the underlying disease that had led to the stoma, depression, problem with location of ostomy, and change in clothing style had significant effects on overall QOL and its subscales (P < 0.05). The results of the regression analyses showed that only depression and problem with the location of ostomy were statistically significant in predicting patients’ QOL and its subscales (P < 0.05). Conclusions: The findings demonstrated that living with stoma influences the overall aspect of QOL. Education for the patients and their families is important for improving the stoma patients’ QOL. Sexual and psychological consultation may also improve patients’ QOL. PMID:23439841

Grey matter volume patterns in thalamic nuclei are associated with familial risk for schizophrenia.

PubMed

Pergola, Giulio; Trizio, Silvestro; Di Carlo, Pasquale; Taurisano, Paolo; Mancini, Marina; Amoroso, Nicola; Nettis, Maria Antonietta; Andriola, Ileana; Caforio, Grazia; Popolizio, Teresa; Rampino, Antonio; Di Giorgio, Annabella; Bertolino, Alessandro; Blasi, Giuseppe

2017-02-01

Previous evidence suggests reduced thalamic grey matter volume (GMV) in patients with schizophrenia (SCZ). However, it is not considered an intermediate phenotype for schizophrenia, possibly because previous studies did not assess the contribution of individual thalamic nuclei and employed univariate statistics. Here, we hypothesized that multivariate statistics would reveal an association of GMV in different thalamic nuclei with familial risk for schizophrenia. We also hypothesized that accounting for the heterogeneity of thalamic GMV in healthy controls would improve the detection of subjects at familial risk for the disorder. We acquired MRI scans for 96 clinically stable SCZ, 55 non-affected siblings of patients with schizophrenia (SIB), and 249 HC. The thalamus was parceled into seven regions of interest (ROIs). After a canonical univariate analysis, we used GMV estimates of thalamic ROIs, together with total thalamic GMV and premorbid intelligence, as features in Random Forests to classify HC, SIB, and SCZ. Then, we computed a Misclassification Index for each individual and tested the improvement in SIB detection after excluding a subsample of HC misclassified as patients. Random Forests discriminated SCZ from HC (accuracy=81%) and SIB from HC (accuracy=75%). Left anteromedial thalamic volumes were significantly associated with both multivariate classifications (p<0.05). Excluding HC misclassified as SCZ improved greatly HC vs. SIB classification (Cohen's d=1.39). These findings suggest that multivariate statistics identify a familial background associated with thalamic GMV reduction in SCZ. They also suggest the relevance of inter-individual variability of GMV patterns for the discrimination of individuals at familial risk for the disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

PROM and Labour Effects on Urinary Metabolome: A Pilot Study

PubMed Central

Meloni, Alessandra; Palmas, Francesco; Mereu, Rossella; Deiana, Sara Francesca; Fais, Maria Francesca; Mussap, Michele; Ragusa, Antonio; Pintus, Roberta; Fanos, Vassilios; Melis, Gian Benedetto

2018-01-01

Since pathologies and complications occurring during pregnancy and/or during labour may cause adverse outcomes for both newborns and mothers, there is a growing interest in metabolomic applications on pregnancy investigation. In fact, metabolomics has proved to be an efficient strategy for the description of several perinatal conditions. In particular, this study focuses on premature rupture of membranes (PROM) in pregnancy at term. For this project, urine samples were collected at three different clinical conditions: out of labour before PROM occurrence (Ph1), out of labour with PROM (Ph2), and during labour with PROM (Ph3). GC-MS analysis, followed by univariate and multivariate statistical analysis, was able to discriminate among the different classes, highlighting the metabolites most involved in the discrimination. PMID:29511388

Conceptual and statistical problems associated with the use of diversity indices in ecology.

PubMed

Barrantes, Gilbert; Sandoval, Luis

2009-09-01

Diversity indices, particularly the Shannon-Wiener index, have extensively been used in analyzing patterns of diversity at different geographic and ecological scales. These indices have serious conceptual and statistical problems which make comparisons of species richness or species abundances across communities nearly impossible. There is often no a single statistical method that retains all information needed to answer even a simple question. However, multivariate analyses could be used instead of diversity indices, such as cluster analyses or multiple regressions. More complex multivariate analyses, such as Canonical Correspondence Analysis, provide very valuable information on environmental variables associated to the presence and abundance of the species in a community. In addition, particular hypotheses associated to changes in species richness across localities, or change in abundance of one, or a group of species can be tested using univariate, bivariate, and/or rarefaction statistical tests. The rarefaction method has proved to be robust to standardize all samples to a common size. Even the simplest method as reporting the number of species per taxonomic category possibly provides more information than a diversity index value.

Early and late fracture following extensive limb lengthening in patients with achondroplasia and hypochondroplasia.

PubMed

Kitoh, H; Mishima, K; Matsushita, M; Nishida, Y; Ishiguro, N

2014-09-01

Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The Mann‑Whitney U test and Pearson's chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened limbs in patients with ACH or HCH. In patients with thin callus formation, some measures to stimulate bone formation should be considered as early as possible. ©2014 The British Editorial Society of Bone & Joint Surgery.

A change in humidification system can eliminate endotracheal tube occlusion.

PubMed

Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter

2011-12-01

Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P < .05 was considered statistically significant. There were 158 patients in the HME group and 88 patients in the HH group. The incidence of endotracheal tube occlusion was 5.7% in the HME group and 0% in the HH group. Statistical analysis revealed a significant difference between the 2 groups (P = .02). In light of this finding, we changed our practice to provide humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.

[Relational database for urinary stone ambulatory consultation. Assessment of initial outcomes].

PubMed

Sáenz Medina, J; Páez Borda, A; Crespo Martinez, L; Gómez Dos Santos, V; Barrado, C; Durán Poveda, M

2010-05-01

To create a relational database for monitoring lithiasic patients. We describe the architectural details and the initial results of the statistical analysis. Microsoft Access 2002 was used as template. Four different tables were constructed to gather demographic data (table 1), clinical and laboratory findings (table 2), stone features (table 3) and therapeutic approach (table 4). For a reliability analysis of the database the number of correctly stored data was gathered. To evaluate the performance of the database, a prospective analysis was conducted, from May 2004 to August 2009, on 171 stone free patients after treatment (EWSL, surgery or medical) from a total of 511 patients stored in the database. Lithiasic status (stone free or stone relapse) was used as primary end point, while demographic factors (age, gender), lithiasic history, upper urinary tract alterations and characteristics of the stone (side, location, composition and size) were considered as predictive factors. An univariate analysis was conducted initially by chi square test and supplemented by Kaplan Meier estimates for time to stone recurrence. A multiple Cox proportional hazards regression model was generated to jointly assess the prognostic value of the demographic factors and the predictive value of stones characteristics. For the reliability analysis 22,084 data were available corresponding to 702 consultations on 511 patients. Analysis of data showed a recurrence rate of 85.4% (146/171, median time to recurrence 608 days, range 70-1758). In the univariate and multivariate analysis, none of the factors under consideration had a significant effect on recurrence rate (p=ns). The relational database is useful for monitoring patients with urolithiasis. It allows easy control and update, as well as data storage for later use. The analysis conducted for its evaluation showed no influence of demographic factors and stone features on stone recurrence.

A Statistical Approach for Testing Cross-Phenotype Effects of Rare Variants

PubMed Central

Broadaway, K. Alaine; Cutler, David J.; Duncan, Richard; Moore, Jacob L.; Ware, Erin B.; Jhun, Min A.; Bielak, Lawrence F.; Zhao, Wei; Smith, Jennifer A.; Peyser, Patricia A.; Kardia, Sharon L.R.; Ghosh, Debashis; Epstein, Michael P.

2016-01-01

Increasing empirical evidence suggests that many genetic variants influence multiple distinct phenotypes. When cross-phenotype effects exist, multivariate association methods that consider pleiotropy are often more powerful than univariate methods that model each phenotype separately. Although several statistical approaches exist for testing cross-phenotype effects for common variants, there is a lack of similar tests for gene-based analysis of rare variants. In order to fill this important gap, we introduce a statistical method for cross-phenotype analysis of rare variants using a nonparametric distance-covariance approach that compares similarity in multivariate phenotypes to similarity in rare-variant genotypes across a gene. The approach can accommodate both binary and continuous phenotypes and further can adjust for covariates. Our approach yields a closed-form test whose significance can be evaluated analytically, thereby improving computational efficiency and permitting application on a genome-wide scale. We use simulated data to demonstrate that our method, which we refer to as the Gene Association with Multiple Traits (GAMuT) test, provides increased power over competing approaches. We also illustrate our approach using exome-chip data from the Genetic Epidemiology Network of Arteriopathy. PMID:26942286

Multivariate pattern dependence

PubMed Central

Saxe, Rebecca

2017-01-01

When we perform a cognitive task, multiple brain regions are engaged. Understanding how these regions interact is a fundamental step to uncover the neural bases of behavior. Most research on the interactions between brain regions has focused on the univariate responses in the regions. However, fine grained patterns of response encode important information, as shown by multivariate pattern analysis. In the present article, we introduce and apply multivariate pattern dependence (MVPD): a technique to study the statistical dependence between brain regions in humans in terms of the multivariate relations between their patterns of responses. MVPD characterizes the responses in each brain region as trajectories in region-specific multidimensional spaces, and models the multivariate relationship between these trajectories. We applied MVPD to the posterior superior temporal sulcus (pSTS) and to the fusiform face area (FFA), using a searchlight approach to reveal interactions between these seed regions and the rest of the brain. Across two different experiments, MVPD identified significant statistical dependence not detected by standard functional connectivity. Additionally, MVPD outperformed univariate connectivity in its ability to explain independent variance in the responses of individual voxels. In the end, MVPD uncovered different connectivity profiles associated with different representational subspaces of FFA: the first principal component of FFA shows differential connectivity with occipital and parietal regions implicated in the processing of low-level properties of faces, while the second and third components show differential connectivity with anterior temporal regions implicated in the processing of invariant representations of face identity. PMID:29155809

Predictors of radio-cephalic arteriovenous fistulae patency in an Asian population.

PubMed

Joseph Lo, Zhiwen; Tay, Wee Ming; Lee, Qinyi; Chua, Jia Long; Tan, Glenn Wei Leong; Chandrasekar, Sadhana; Narayanan, Sriram

2016-09-21

To identify predictors of arteriovenous fistula (AVF) patency in Asian patients with autogenous radio-cephalic arteriovenous fistula (RCAVF). Retrospective review of 436 RCAVFs created between 2009 and 2013. Predictors of patency were identified with univariate and multivariate analysis. Kaplan-Meier survival analysis and log-rank test were used to calculate patency rates. Overall secondary patency rate was 72% at 12 months, 69% at 24 months, 58% at 36 months, 57% at 48 months, 56% at 60 months and 54% at 72 months. Univariate analysis showed that factors which predict for patency include male gender (p = 0.003), good diabetic control (p = 0.025), aspirin use (p = 0.031), pre-dialysis status (p = 0.037), radial artery diameter (p = 0.029) and non-calcified radial arteries (p = 0.002). Age (p = 0.866), cephalic vein diameter (p = 0.630) and surgeon grade (p = 0.472) did not predict for primary AVF failure. Multivariate analysis revealed the male gender to be an independent predictor for patency (odds ratio 1.99, p = 0.01). Subset analysis showed a significantly larger average radial artery diameter of 2.3 mm amongst males, as compared to 1.9 mm amongst females (p = 0.001) and no statistical difference in the average cephalic vein diameter. Within our Asian study population, 12-month patency rate of RCAVF is 72%, 69% at 24 months, 58% at 36 months, 57% at 48 months, 56% at 60 months and 54% at 72 months. Male gender is an independent predictor for RCAVF patency. In females or patients with calcified radial arteries, a more proximal AVF should be considered.

The microbiological profile and presence of bloodstream infection influence mortality rates in necrotizing fasciitis

PubMed Central

2011-01-01

Introduction Necrotizing fasciitis (NF) is a life threatening infectious disease with a high mortality rate. We carried out a microbiological characterization of the causative pathogens. We investigated the correlation of mortality in NF with bloodstream infection and with the presence of co-morbidities. Methods In this retrospective study, we analyzed 323 patients who presented with necrotizing fasciitis at two different institutions. Bloodstream infection (BSI) was defined as a positive blood culture result. The patients were categorized as survivors and non-survivors. Eleven clinically important variables which were statistically significant by univariate analysis were selected for multivariate regression analysis and a stepwise logistic regression model was developed to determine the association between BSI and mortality. Results Univariate logistic regression analysis showed that patients with hypotension, heart disease, liver disease, presence of Vibrio spp. in wound cultures, presence of fungus in wound cultures, and presence of Streptococcus group A, Aeromonas spp. or Vibrio spp. in blood cultures, had a significantly higher risk of in-hospital mortality. Our multivariate logistic regression analysis showed a higher risk of mortality in patients with pre-existing conditions like hypotension, heart disease, and liver disease. Multivariate logistic regression analysis also showed that presence of Vibrio spp in wound cultures, and presence of Streptococcus Group A in blood cultures were associated with a high risk of mortality while debridement > = 3 was associated with improved survival. Conclusions Mortality in patients with necrotizing fasciitis was significantly associated with the presence of Vibrio in wound cultures and Streptococcus group A in blood cultures. PMID:21693053

Venous Thromboembolism Requiring Extended Anticoagulation Among HIV-Infected Patients in a Rural, Resource-Constrained Setting in Western Kenya.

PubMed

Kanyi, John; Karwa, Rakhi; Pastakia, Sonak Dinesh; Manji, Imran; Manyara, Simon; Saina, Collins

2017-05-01

HIV-infected patients are at an increased risk of developing venous thromboembolism (VTE), and minimal data are available to describe the need for extended treatment. To evaluate the frequency of and determine predictive risk factors for extended anticoagulation of VTE in HIV-infected patients in rural, western Kenya. A retrospective chart review was conducted at the Anticoagulation Monitoring Service affiliated with Moi Teaching and Referral Hospital and the Academic Model Providing Access to Healthcare. Data were collected on patients who were HIV-infected and receiving anticoagulation for lower-limb deep vein thrombosis. The need for extended anticoagulation, defined as receiving ≥7 months of warfarin therapy, was established based on patient symptoms or Doppler ultrasound-confirmed diagnosis. Evaluation of the secondary outcomes utilized a univariate analysis to identify risk factors associated with extended anticoagulation. A total of 71 patients were included in the analysis; 27 patients (38%) required extended anticoagulation. The univariate analysis showed a statistically significant association between the need for extended anticoagulation and achieving a therapeutic international normalized ratio within 21 days in both the unadjusted and adjusted analysis. Patients with a history of opportunistic infections required an extended duration of anticoagulation in the adjusted analysis: odds ratio = 3.42; 95% CI = 1.04-11.32; P = 0.04. This study shows that there may be a need for increased duration of anticoagulation in HIV-infected patients, with a need to address the issue of long-term management. Guideline recommendations are needed to address the complexity of treatment issues in this population.

The Efficacy of Two Improvement-over-Chance Effect Sizes for Two-Group Univariate Comparisons under Variance Heterogeneity and Nonnormality.

ERIC Educational Resources Information Center

Hess, Brian; Olejnik, Stephen; Huberty, Carl J.

2001-01-01

Studied the efficacy of two improvement-over-chance or "I" effect sizes derived from predictive discriminant analysis and logistic regression analysis for two-group univariate mean comparisons through simulation. Discusses the ways in which the usefulness of each of the indices depends on the population characteristics. (SLD)

Significant Association of Urinary Toxic Metals and Autism-Related Symptoms—A Nonlinear Statistical Analysis with Cross Validation

PubMed Central

Adams, James; Kruger, Uwe; Geis, Elizabeth; Gehn, Eva; Fimbres, Valeria; Pollard, Elena; Mitchell, Jessica; Ingram, Julie; Hellmers, Robert; Quig, David; Hahn, Juergen

2017-01-01

Introduction A number of previous studies examined a possible association of toxic metals and autism, and over half of those studies suggest that toxic metal levels are different in individuals with Autism Spectrum Disorders (ASD). Additionally, several studies found that those levels correlate with the severity of ASD. Methods In order to further investigate these points, this paper performs the most detailed statistical analysis to date of a data set in this field. First morning urine samples were collected from 67 children and adults with ASD and 50 neurotypical controls of similar age and gender. The samples were analyzed to determine the levels of 10 urinary toxic metals (UTM). Autism-related symptoms were assessed with eleven behavioral measures. Statistical analysis was used to distinguish participants on the ASD spectrum and neurotypical participants based upon the UTM data alone. The analysis also included examining the association of autism severity with toxic metal excretion data using linear and nonlinear analysis. “Leave-one-out” cross-validation was used to ensure statistical independence of results. Results and Discussion Average excretion levels of several toxic metals (lead, tin, thallium, antimony) were significantly higher in the ASD group. However, ASD classification using univariate statistics proved difficult due to large variability, but nonlinear multivariate statistical analysis significantly improved ASD classification with Type I/II errors of 15% and 18%, respectively. These results clearly indicate that the urinary toxic metal excretion profiles of participants in the ASD group were significantly different from those of the neurotypical participants. Similarly, nonlinear methods determined a significantly stronger association between the behavioral measures and toxic metal excretion. The association was strongest for the Aberrant Behavior Checklist (including subscales on Irritability, Stereotypy, Hyperactivity, and Inappropriate Speech), but significant associations were found for UTM with all eleven autism-related assessments with cross-validation R2 values ranging from 0.12–0.48. PMID:28068407

Association of the Shared Epitope, Smoking and the Interaction Between the Two With the Presence of Autoantibodies (Anti-CCP and FR) in Patients With Rheumatoid Arthritis in a Hospital in Seville, Spain.

PubMed

García de Veas Silva, José Luis; González Rodríguez, Concepción; Hernández Cruz, Blanca

2017-11-01

To evaluate the association of shared epitope, smoking and their interaction on the presence of autoantibodies (anti-cyclic citrullinated peptide [CCP] antibodies and rheumatoid factor) in patients with rheumatoid arthritis in our geographical area. A descriptive and cross-sectional study was carried out in a cohort of 106 patients diagnosed with RA. Odds ratios (OR) for antibody development were calculated for shared epitope, tobacco exposure and smoking dose. Statistical analysis was performed with univariate and multivariate statistics using ordinal logistic regression. Odds ratios were calculated with 95% confidence interval (95% CI) and a value of P<.05 was considered significant. In univariate analysis, shared epitope (OR=2.68; 95% CI: 1.11-6.46), tobacco exposure (OR=2.79; 95% CI: 1.12-6.97) and heavy smoker (>20 packs/year) (OR=8.93; 95% CI: 1.95-40.82) were associated with the presence of anti-CCP antibodies. For rheumatoid factor, the association was only significant for tobacco exposure (OR=3.89; 95% CI: 1.06-14.28) and smoking dose (OR=8.33; 95% CI: 1.05-66.22). By ordinal logistic regression analysis, an association with high titers of anti-CCP (>200U/mL) was identified with South American mestizos, patients with homozygous shared epitope, positive FR and heavy smokers. Being a South American mestizo, having a shared epitope, rheumatoid factor positivity and a smoking dose>20 packs/year are independent risk factors for the development of rheumatoid arthritis with a high titer of anti-CCP (>200U/mL). In shared epitope-positive rheumatoid arthritis patients, the intensity of smoking is more strongly associated than tobacco exposure with an increased risk of positive anti-CCP. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Dietary predictors of childhood obesity in a representative sample of children in north east of Iran.

PubMed

Baygi, Fereshteh; Qorbani, Mostafa; Dorosty, Ahmad Reza; Kelishadi, Roya; Asayesh, Hamid; Rezapour, Aziz; Mohammadi, Younes; Mohammadi, Fatemeh

2013-07-01

The prevalence of obesity is increasing in Iranian youngsters. This study aimed to assess some dietary determinants of obesity in a representative sample of children in Neishabour, a city in northeastern, Iran. This case-control study was conducted among 114 school students, aged 6-12 years, with a body mass index (BMI) ≥95th (based on percentile of Iranian children) as the case group and 102 age- and gender-matched controls, who were selected from their non-obese classmates. Nutrient intake data were collected by trained nutritionists by using two 24-hour-dietary recalls through maternal interviews in the presence of their child. A food frequency questionnaire was used for detecting the snack consumption patterns. Statistical analysis was done using univariate and multivariate logistic regression (MLR) by SPSS version 16. In univariate logistic regression, total energy, protein, carbohydrate, fat (including saturated, mono- and poly-unsaturated fat), and dietary fiber were the positive predictors of obesity in studied children. The estimated crude ORs for frequency of corn-based extruded snacks, carbonated beverages, potato chips, fast foods, and chocolate consumption were statistically significant. After MLR analysis, the association of obesity remained significant with energy intake (OR = 2.489, 95%CI: 1.667-3.716), frequency of corn-based extruded snacks (OR = 1.122, 95%CI: 1.007-1.250), and potato chips (OR = 1.143, 95%CI:1.024-1.276). The MLR analysis showed that dietary fiber (OR = 0.601, 95%CI: 0.368-0.983) and natural fruit juice intake (OR = 0.909, 95%CI: 0.835-0.988) were protective factors against obesity. The findings serve to confirm the role of an unhealthy diet, notably calorie-dense snacks, in childhood obesity. Healthy dietary habits, such as the consumption of high-fiber foods, should be encouraged among children.

Applications of multivariate modeling to neuroimaging group analysis: a comprehensive alternative to univariate general linear model.

PubMed

Chen, Gang; Adleman, Nancy E; Saad, Ziad S; Leibenluft, Ellen; Cox, Robert W

2014-10-01

All neuroimaging packages can handle group analysis with t-tests or general linear modeling (GLM). However, they are quite hamstrung when there are multiple within-subject factors or when quantitative covariates are involved in the presence of a within-subject factor. In addition, sphericity is typically assumed for the variance-covariance structure when there are more than two levels in a within-subject factor. To overcome such limitations in the traditional AN(C)OVA and GLM, we adopt a multivariate modeling (MVM) approach to analyzing neuroimaging data at the group level with the following advantages: a) there is no limit on the number of factors as long as sample sizes are deemed appropriate; b) quantitative covariates can be analyzed together with within-subject factors; c) when a within-subject factor is involved, three testing methodologies are provided: traditional univariate testing (UVT) with sphericity assumption (UVT-UC) and with correction when the assumption is violated (UVT-SC), and within-subject multivariate testing (MVT-WS); d) to correct for sphericity violation at the voxel level, we propose a hybrid testing (HT) approach that achieves equal or higher power via combining traditional sphericity correction methods (Greenhouse-Geisser and Huynh-Feldt) with MVT-WS. To validate the MVM methodology, we performed simulations to assess the controllability for false positives and power achievement. A real FMRI dataset was analyzed to demonstrate the capability of the MVM approach. The methodology has been implemented into an open source program 3dMVM in AFNI, and all the statistical tests can be performed through symbolic coding with variable names instead of the tedious process of dummy coding. Our data indicates that the severity of sphericity violation varies substantially across brain regions. The differences among various modeling methodologies were addressed through direct comparisons between the MVM approach and some of the GLM implementations in the field, and the following two issues were raised: a) the improper formulation of test statistics in some univariate GLM implementations when a within-subject factor is involved in a data structure with two or more factors, and b) the unjustified presumption of uniform sphericity violation and the practice of estimating the variance-covariance structure through pooling across brain regions. Published by Elsevier Inc.

Multivariate Methods for Meta-Analysis of Genetic Association Studies.

PubMed

Dimou, Niki L; Pantavou, Katerina G; Braliou, Georgia G; Bagos, Pantelis G

2018-01-01

Multivariate meta-analysis of genetic association studies and genome-wide association studies has received a remarkable attention as it improves the precision of the analysis. Here, we review, summarize and present in a unified framework methods for multivariate meta-analysis of genetic association studies and genome-wide association studies. Starting with the statistical methods used for robust analysis and genetic model selection, we present in brief univariate methods for meta-analysis and we then scrutinize multivariate methodologies. Multivariate models of meta-analysis for a single gene-disease association studies, including models for haplotype association studies, multiple linked polymorphisms and multiple outcomes are discussed. The popular Mendelian randomization approach and special cases of meta-analysis addressing issues such as the assumption of the mode of inheritance, deviation from Hardy-Weinberg Equilibrium and gene-environment interactions are also presented. All available methods are enriched with practical applications and methodologies that could be developed in the future are discussed. Links for all available software implementing multivariate meta-analysis methods are also provided.

Validated univariate and multivariate spectrophotometric methods for the determination of pharmaceuticals mixture in complex wastewater

NASA Astrophysics Data System (ADS)

Riad, Safaa M.; Salem, Hesham; Elbalkiny, Heba T.; Khattab, Fatma I.

2015-04-01

Five, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its λmax 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p = 0.05.

Validated univariate and multivariate spectrophotometric methods for the determination of pharmaceuticals mixture in complex wastewater.

PubMed

Riad, Safaa M; Salem, Hesham; Elbalkiny, Heba T; Khattab, Fatma I

2015-04-05

Five, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its λmax 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p=0.05. Copyright © 2015 Elsevier B.V. All rights reserved.

Do Angiotensin-Converting Enzyme Inhibitors Reduce the Risk of Symptomatic Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer After Definitive Radiation Therapy? Analysis of a Single-Institution Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hongmei; Liao, Zhongxing, E-mail: zliao@mdanderson.org; Zhuang, Yan

2013-12-01

Purpose: Preclinical studies have suggested that angiotensin-converting enzyme inhibitors (ACEIs) can mitigate radiation-induced lung injury. We sought here to investigate possible associations between ACEI use and the risk of symptomatic radiation pneumonitis (RP) among patients undergoing radiation therapy (RT) for non–small cell lung cancer (NSCLC). Methods and Materials: We retrospectively identified patients who received definitive radiation therapy for stages I to III NSCLC between 2004 and 2010 at a single tertiary cancer center. Patients must have received a radiation dose of at least 60 Gy for a single primary lung tumor and have had imaging and dosimetric data available formore » analysis. RP was quantified according to Common Terminology Criteria for Adverse Events, version 3.0. A Cox proportional hazard model was used to assess potential associations between ACEI use and risk of symptomatic RP. Results: Of 413 patients analyzed, 65 were using ACEIs during RT. In univariate analysis, the rate of RP grade ≥2 seemed lower in ACEI users than in nonusers (34% vs 46%), but this apparent difference was not statistically significant (P=.06). In multivariate analysis of all patients, ACEI use was not associated with the risk of symptomatic RP (hazard ratio [HR] = 0.66; P=.07) after adjustment for sex, smoking status, mean lung dose (MLD), and concurrent carboplatin and paclitaxel chemotherapy. Subgroup analysis showed that ACEI use did have a protective effect from RP grade ≥2 among patients who received a low (≤20-Gy) MLD (P<.01) or were male (P=.04). Conclusions: A trend toward reduction in symptomatic RP among patients taking ACEIs during RT for NSCLC was not statistically significant on univariate or multivariate analyses, although certain subgroups may benefit from use (ie, male patients and those receiving low MLD). The evidence at this point is insufficient to establish whether the use of ACEIs does or does not reduce the risk of RP.« less

Comparison of univariate and multivariate models for prediction of major and minor elements from laser-induced breakdown spectra with and without masking

NASA Astrophysics Data System (ADS)

Dyar, M. Darby; Fassett, Caleb I.; Giguere, Stephen; Lepore, Kate; Byrne, Sarah; Boucher, Thomas; Carey, CJ; Mahadevan, Sridhar

2016-09-01

This study uses 1356 spectra from 452 geologically-diverse samples, the largest suite of LIBS rock spectra ever assembled, to compare the accuracy of elemental predictions in models that use only spectral regions thought to contain peaks arising from the element of interest versus those that use information in the entire spectrum. Results show that for the elements Si, Al, Ti, Fe, Mg, Ca, Na, K, Ni, Mn, Cr, Co, and Zn, univariate predictions based on single emission lines are by far the least accurate, no matter how carefully the region of channels/wavelengths is chosen and despite the prominence of the selected emission lines. An automated iterative algorithm was developed to sweep through all 5485 channels of data and select the single region that produces the optimal prediction accuracy for each element using univariate analysis. For the eight major elements, use of this technique results in a 35% improvement in prediction accuracy; for minors, the improvement is 13%. The best wavelength region choice for any given univariate analysis is likely to be an inherent property of the specific training set that cannot be generalized. In comparison, multivariate analysis using partial least-squares (PLS) almost universally outperforms univariate analysis. PLS using all the same wavelength regions from the univariate analysis produces results that improve in accuracy by 63% for major elements and 3% for minor element. This difference is likely a reflection of signal to noise ratios, which are far better for major elements than for minor elements, and likely limit their prediction accuracy by any technique. We also compare predictions using specific wavelength ranges for each element against those employing all channels. Masking out channels to focus on emission lines from a specific element that occurs decreases prediction accuracy for major elements but is useful for minor elements with low signals and proportionally much higher noise; use of PLS rather than univariate analysis is still recommended. Finally, we tested the generalizability of our results by analyzing a second data set from a different instrument. Overall prediction accuracies for the mixed data sets are higher than for either set alone for all major and minor elements except Ni, Cr, and Co, where results are roughly comparable.

THE DISTRIBUTION OF COOK’S D STATISTIC

PubMed Central

Muller, Keith E.; Mok, Mario Chen

2013-01-01

Cook (1977) proposed a diagnostic to quantify the impact of deleting an observation on the estimated regression coefficients of a General Linear Univariate Model (GLUM). Simulations of models with Gaussian response and predictors demonstrate that his suggestion of comparing the diagnostic to the median of the F for overall regression captures an erratically varying proportion of the values. We describe the exact distribution of Cook’s statistic for a GLUM with Gaussian predictors and response. We also present computational forms, simple approximations, and asymptotic results. A simulation supports the accuracy of the results. The methods allow accurate evaluation of a single value or the maximum value from a regression analysis. The approximations work well for a single value, but less well for the maximum. In contrast, the cut-point suggested by Cook provides widely varying tail probabilities. As with all diagnostics, the data analyst must use scientific judgment in deciding how to treat highlighted observations. PMID:24363487

Pretreatment health behaviors predict survival among patients with head and neck squamous cell carcinoma.

PubMed

Duffy, Sonia A; Ronis, David L; McLean, Scott; Fowler, Karen E; Gruber, Stephen B; Wolf, Gregory T; Terrell, Jeffrey E

2009-04-20

Our prior work has shown that the health behaviors of head and neck cancer patients are interrelated and are associated with quality of life; however, other than smoking, the relationship between health behaviors and survival is unclear. A prospective cohort study was conducted to determine the relationship between five pretreatment health behaviors (smoking, alcohol, diet, physical activity, and sleep) and all-cause survival among 504 head and neck cancer patients. Smoking status was the strongest predictor of survival, with both current smokers (hazard ratio [HR] = 2.4; 95% CI, 1.3 to 4.4) and former smokers (HR = 2.0; 95% CI, 1.2 to 3.5) showing significant associations with poor survival. Problem drinking was associated with survival in the univariate analysis (HR = 1.4; 95% CI, 1.0 to 2.0) but lost significance when controlling for other factors. Low fruit intake was negatively associated with survival in the univariate analysis only (HR = 1.6; 95% CI, 1.1 to 2.1), whereas vegetable intake was not significant in either univariate or multivariate analyses. Although physical activity was associated with survival in the univariate analysis (HR = 0.95; 95% CI, 0.93 to 0.97), it was not significant in the multivariate model. Sleep was not significantly associated with survival in either univariate or multivariate analysis. Control variables that were also independently associated with survival in the multivariate analysis were age, education, tumor site, cancer stage, and surgical treatment. Variation in selected pretreatment health behaviors (eg, smoking, fruit intake, and physical activity) in this population is associated with variation in survival.

Scout 2008 Version 1.0 User Guide

EPA Science Inventory

The Scout 2008 version 1.0 software package provides a wide variety of classical and robust statistical methods that are not typically available in other commercial software packages. A major part of Scout deals with classical, robust, and resistant univariate and multivariate ou...

Multivariate stochastic analysis for Monthly hydrological time series at Cuyahoga River Basin

NASA Astrophysics Data System (ADS)

zhang, L.

2011-12-01

Copula has become a very powerful statistic and stochastic methodology in case of the multivariate analysis in Environmental and Water resources Engineering. In recent years, the popular one-parameter Archimedean copulas, e.g. Gumbel-Houggard copula, Cook-Johnson copula, Frank copula, the meta-elliptical copula, e.g. Gaussian Copula, Student-T copula, etc. have been applied in multivariate hydrological analyses, e.g. multivariate rainfall (rainfall intensity, duration and depth), flood (peak discharge, duration and volume), and drought analyses (drought length, mean and minimum SPI values, and drought mean areal extent). Copula has also been applied in the flood frequency analysis at the confluences of river systems by taking into account the dependence among upstream gauge stations rather than by using the hydrological routing technique. In most of the studies above, the annual time series have been considered as stationary signal which the time series have been assumed as independent identically distributed (i.i.d.) random variables. But in reality, hydrological time series, especially the daily and monthly hydrological time series, cannot be considered as i.i.d. random variables due to the periodicity existed in the data structure. Also, the stationary assumption is also under question due to the Climate Change and Land Use and Land Cover (LULC) change in the fast years. To this end, it is necessary to revaluate the classic approach for the study of hydrological time series by relaxing the stationary assumption by the use of nonstationary approach. Also as to the study of the dependence structure for the hydrological time series, the assumption of same type of univariate distribution also needs to be relaxed by adopting the copula theory. In this paper, the univariate monthly hydrological time series will be studied through the nonstationary time series analysis approach. The dependence structure of the multivariate monthly hydrological time series will be studied through the copula theory. As to the parameter estimation, the maximum likelihood estimation (MLE) will be applied. To illustrate the method, the univariate time series model and the dependence structure will be determined and tested using the monthly discharge time series of Cuyahoga River Basin.

Pleiotropy Analysis of Quantitative Traits at Gene Level by Multivariate Functional Linear Models

PubMed Central

Wang, Yifan; Liu, Aiyi; Mills, James L.; Boehnke, Michael; Wilson, Alexander F.; Bailey-Wilson, Joan E.; Xiong, Momiao; Wu, Colin O.; Fan, Ruzong

2015-01-01

In genetics, pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. A common approach is to analyze the phenotypic traits separately using univariate analyses and combine the test results through multiple comparisons. This approach may lead to low power. Multivariate functional linear models are developed to connect genetic variant data to multiple quantitative traits adjusting for covariates for a unified analysis. Three types of approximate F-distribution tests based on Pillai–Bartlett trace, Hotelling–Lawley trace, and Wilks’s Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants in one genetic region. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and optimal sequence kernel association test (SKAT-O). Extensive simulations were performed to evaluate the false positive rates and power performance of the proposed models and tests. We show that the approximate F-distribution tests control the type I error rates very well. Overall, simultaneous analysis of multiple traits can increase power performance compared to an individual test of each trait. The proposed methods were applied to analyze (1) four lipid traits in eight European cohorts, and (2) three biochemical traits in the Trinity Students Study. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and SKAT-O for the three biochemical traits. The approximate F-distribution tests of the proposed functional linear models are more sensitive than those of the traditional multivariate linear models that in turn are more sensitive than SKAT-O in the univariate case. The analysis of the four lipid traits and the three biochemical traits detects more association than SKAT-O in the univariate case. PMID:25809955

Pleiotropy analysis of quantitative traits at gene level by multivariate functional linear models.

PubMed

Wang, Yifan; Liu, Aiyi; Mills, James L; Boehnke, Michael; Wilson, Alexander F; Bailey-Wilson, Joan E; Xiong, Momiao; Wu, Colin O; Fan, Ruzong

2015-05-01

In genetics, pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. A common approach is to analyze the phenotypic traits separately using univariate analyses and combine the test results through multiple comparisons. This approach may lead to low power. Multivariate functional linear models are developed to connect genetic variant data to multiple quantitative traits adjusting for covariates for a unified analysis. Three types of approximate F-distribution tests based on Pillai-Bartlett trace, Hotelling-Lawley trace, and Wilks's Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants in one genetic region. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and optimal sequence kernel association test (SKAT-O). Extensive simulations were performed to evaluate the false positive rates and power performance of the proposed models and tests. We show that the approximate F-distribution tests control the type I error rates very well. Overall, simultaneous analysis of multiple traits can increase power performance compared to an individual test of each trait. The proposed methods were applied to analyze (1) four lipid traits in eight European cohorts, and (2) three biochemical traits in the Trinity Students Study. The approximate F-distribution tests provide much more significant results than those of F-tests of univariate analysis and SKAT-O for the three biochemical traits. The approximate F-distribution tests of the proposed functional linear models are more sensitive than those of the traditional multivariate linear models that in turn are more sensitive than SKAT-O in the univariate case. The analysis of the four lipid traits and the three biochemical traits detects more association than SKAT-O in the univariate case. © 2015 WILEY PERIODICALS, INC.

Diagnostic Classification of Schizophrenia Patients on the Basis of Regional Reward-Related fMRI Signal Patterns

PubMed Central

Koch, Stefan P.; Hägele, Claudia; Haynes, John-Dylan; Heinz, Andreas; Schlagenhauf, Florian; Sterzer, Philipp

2015-01-01

Functional neuroimaging has provided evidence for altered function of mesolimbic circuits implicated in reward processing, first and foremost the ventral striatum, in patients with schizophrenia. While such findings based on significant group differences in brain activations can provide important insights into the pathomechanisms of mental disorders, the use of neuroimaging results from standard univariate statistical analysis for individual diagnosis has proven difficult. In this proof of concept study, we tested whether the predictive accuracy for the diagnostic classification of schizophrenia patients vs. healthy controls could be improved using multivariate pattern analysis (MVPA) of regional functional magnetic resonance imaging (fMRI) activation patterns for the anticipation of monetary reward. With a searchlight MVPA approach using support vector machine classification, we found that the diagnostic category could be predicted from local activation patterns in frontal, temporal, occipital and midbrain regions, with a maximal cluster peak classification accuracy of 93% for the right pallidum. Region-of-interest based MVPA for the ventral striatum achieved a maximal cluster peak accuracy of 88%, whereas the classification accuracy on the basis of standard univariate analysis reached only 75%. Moreover, using support vector regression we could additionally predict the severity of negative symptoms from ventral striatal activation patterns. These results show that MVPA can be used to substantially increase the accuracy of diagnostic classification on the basis of task-related fMRI signal patterns in a regionally specific way. PMID:25799236

Retrospective study of adjuvant icotinib in postoperative lung cancer patients harboring epidermal growth factor receptor mutations

PubMed Central

Yao, Shuyang; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu

2016-01-01

Background Epidermal growth factor receptor (EGFR) mutations occur in about 50% of Asian patients with non‐small cell lung cancer (NSCLC). Patients with advanced NSCLC and EGFR mutations derive clinical benefit from treatment with EGFR‐tyrosine kinase inhibitors (TKIs). This study assessed the efficacy and safety of adjuvant icotinib without chemotherapy in EGFR‐mutated NSCLC patients undergoing resection of stage IB–IIIA. Methods Our retrospective study enrolled 20 patients treated with icotinib as adjuvant therapy. Survival factors were evaluated by univariate and Cox regression analysis. Results The median follow‐up time was 30 months (range 24–41). At the data cut‐off, five patients (25%) had recurrence or metastasis and one patient had died of the disease. The two‐year disease‐free survival (DFS) rate was 85%. No recurrence occurred in the high‐risk stage IB subgroup during the follow‐up period. In univariate analysis, the micropapillary pattern had a statistically significant effect on DFS (P = 0.040). Multivariate logistic regression analysis showed that there was no independent predictor. Drug related adverse events (AEs) occurred in nine patients (45.0%). The most common AEs were skin‐related events and diarrhea, but were relatively mild. No grade 3 AEs or occurrences of intolerable toxicity were observed. Conclusions Icotinib as adjuvant therapy is effective in patients harboring EGFR mutations after complete resection, with an acceptable AE profile. Further trials with larger sample sizes might confirm the efficiency of adjuvant TKI in selected patients. PMID:27766784

The prognosis analysis of different metastasis pattern in patients with different breast cancer subtypes: a SEER based study.

PubMed

Wang, Haiyong; Zhang, Chenyue; Zhang, Jingze; Kong, Li; Zhu, Hui; Yu, Jinming

2017-04-18

Studies on prognosis of different metastasis patterns in patients with different breast cancer subtypes (BCS) are limited. Therefore, we identified 7862 breast cancer patients with distant metastasis from 2010 to 2013 using Surveillance, Epidemiology, wand End Results (SEER) population-based data. The results showed that bone was the most common metastatic site and brain was the least common metastatic site, and the patients with HR+/HER2- occupied the highest metastasis proportion, the lowest metastasis proportion were found in HR-/HER2+ patients. Univariate and multivariate logistic regression analysis were used to analyze the association, and it was found that there were significant differences of distant metastasis patterns in patients with different BCS(different P value). Importantly, univariate and multivariate Cox regression analysis were used to analyze the prognosis. It was proven that only bone metastasis was not a prognostic factor in the HR+/HER2-, HR+/HER2+ and HR-/HER2+ subgroup (all, P > 0.05), and patients with brain metastasis had the worst cancer specific survival (CSS) in all the subgroups of BCS (all, P<0.01). Interestingly, for patients with two metastatic sites, those with bone and lung metastasis had best CSS in the HR+/HER2- (P<0.001) and HR+/HER2+ subgroups (P=0.009) However, for patients with three and four metastatic sites, there was no statistical difference in their CSS (all, P>0.05).

The prognosis analysis of different metastasis pattern in patients with different breast cancer subtypes: a SEER based study

PubMed Central

Wang, Haiyong; Zhang, Chenyue; Zhang, Jingze; Kong, Li; Zhu, Hui; Yu, Jinming

2017-01-01

Studies on prognosis of different metastasis patterns in patients with different breast cancer subtypes (BCS) are limited. Therefore, we identified 7862 breast cancer patients with distant metastasis from 2010 to 2013 using Surveillance, Epidemiology, wand End Results (SEER) population-based data. The results showed that bone was the most common metastatic site and brain was the least common metastatic site, and the patients with HR+/HER2− occupied the highest metastasis proportion, the lowest metastasis proportion were found in HR-/HER2+ patients. Univariate and multivariate logistic regression analysis were used to analyze the association, and it was found that there were significant differences of distant metastasis patterns in patients with different BCS(different P value). Importantly, univariate and multivariate Cox regression analysis were used to analyze the prognosis. It was proven that only bone metastasis was not a prognostic factor in the HR+/HER2-, HR+/HER2+ and HR-/HER2+ subgroup (all, P > 0.05), and patients with brain metastasis had the worst cancer specific survival (CSS) in all the subgroups of BCS (all, P<0.01). Interestingly, for patients with two metastatic sites, those with bone and lung metastasis had best CSS in the HR+/HER2- (P<0.001) and HR+/HER2+ subgroups (P=0.009) However, for patients with three and four metastatic sites, there was no statistical difference in their CSS (all, P>0.05). PMID:28038448

Gender Inequality: Is the National Population Policy's Objective of Two Child Norm Heading the Correct Way?

PubMed

Patrikar, S R; Bhalwar, R; Datta, A; Basannar, D R

2008-07-01

Male Preference is well known phenomena world wide from ancient ages. A descriptive study was carried out to assess the attitude of women towards birth of son, use of contraception methods and sex determination methods in rural village Kasurdi in Pune district. Univariate analysis was carried out by considering each factor determining sex preference separately as well as using a Logistic Regression Model. Adequacy of fit of the model has also been tested. Out of 110 respondents interviewed, 62.7% felt that male child is necessary in the family. Univariate analysis revealed that sex of first child, concern undergone for second pregnancy with regards to sex of the child, number of children in family and type of family were significant factors contributing to the son preference. The analysis under the logistic regression model revealed that sex of the first child and concern undergone in second pregnancy with respect to the sex of the second child are the most dominating and significant factors in the causation of son preference. The difference between family sizes when compared with the sex of first child was statistically significant signifying that if the first child is a male then it hardly matters whether the second child is male or female, but if the sex of first child is female then the families land up with bigger family size. On an average most of the respondents favour two children with an equal share of male and female children.

Evaluation of clinical, laboratory and morphologic prognostic factors in colon cancer

PubMed Central

Grande, Michele; Milito, Giovanni; Attinà, Grazia Maria; Cadeddu, Federica; Muzi, Marco Gallinella; Nigro, Casimiro; Rulli, Francesco; Farinon, Attilio Maria

2008-01-01

Background The long-term prognosis of patients with colon cancer is dependent on many factors. To investigate the influence of a series of clinical, laboratory and morphological variables on prognosis of colon carcinoma we conducted a retrospective analysis of our data. Methods Ninety-two patients with colon cancer, who underwent surgical resection between January 1999 and December 2001, were analyzed. On survival analysis, demographics, clinical, laboratory and pathomorphological parameters were tested for their potential prognostic value. Furthermore, univariate and multivariate analysis of the above mentioned data were performed considering the depth of tumour invasion into the bowel wall as independent variable. Results On survival analysis we found that depth of tumour invasion (P < 0.001; F-ratio 2.11), type of operation (P < 0.001; F-ratio 3.51) and CT scanning (P < 0.001; F-ratio 5.21) were predictors of survival. Considering the degree of mural invasion as independent variable, on univariate analysis, we observed that mucorrhea, anismus, hematocrit, WBC count, fibrinogen value and CT scanning were significantly related to the degree of mural invasion of the cancer. On the multivariate analysis, fibrinogen value was the most statistically significant variable (P < 0.001) with the highest F-ratio (F-ratio 5.86). Finally, in the present study, the tumour site was significantly related neither to the survival nor to the mural invasion of the tumour. Conclusion The various clinical, laboratory and patho-morphological parameters showed different prognostic value for colon carcinoma. In the future, preoperative prognostic markers will probably gain relevance in order to make a proper choice between surgery, chemotherapy and radiotherapy. Nevertheless, current data do not provide sufficient evidence for preoperative stratification of high and low risk patients. Further assessments in prospective large studies are warranted. PMID:18778464

Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: an SPSS method to analyze univariate data.

PubMed

Maric, Marija; de Haan, Else; Hogendoorn, Sanne M; Wolters, Lidewij H; Huizenga, Hilde M

2015-03-01

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a data-analytic method to analyze univariate (i.e., one symptom) single-case data using the common package SPSS. This method can help the clinical researcher to investigate whether an intervention works as compared with a baseline period or another intervention type, and to determine whether symptom improvement is clinically significant. First, we describe the statistical method in a conceptual way and show how it can be implemented in SPSS. Simulation studies were performed to determine the number of observation points required per intervention phase. Second, to illustrate this method and its implications, we present a case study of an adolescent with anxiety disorders treated with cognitive-behavioral therapy techniques in an outpatient psychotherapy clinic, whose symptoms were regularly assessed before each session. We provide a description of the data analyses and results of this case study. Finally, we discuss the advantages and shortcomings of the proposed method. Copyright © 2014. Published by Elsevier Ltd.

The Effect of Coffee and Quantity of Consumption on Specific Cardiovascular and All-Cause Mortality: Coffee Consumption Does Not Affect Mortality.

PubMed

Loomba, Rohit S; Aggarwal, Saurabh; Arora, Rohit R

2016-01-01

Previous studies have examined whether or not an association exists between the consumption of caffeinated coffee to all-cause and cardiovascular mortality. This study aimed to delineate this association using population representative data from the National Health and Nutrition Examination Survey III. Patients were included in the study if all the following criteria were met: (1) follow-up mortality data were available, (2) age of at least 45 years, and (3) reported amount of average coffee consumption. A total of 8608 patients were included, with patients stratified into the following groups of average daily coffee consumption: (1) no coffee consumption, (2) less than 1 cup, (3) 1 cup a day, (4) 2-3 cups, (5) 4-5 cups, (6) more than 6 cups a day. Odds ratios, 95% confidence intervals, and P values were calculated for univariate analysis to compare the prevalence of all-cause mortality, ischemia-related mortality, congestive heart failure-related mortality, and stroke-related mortality, using the no coffee consumption group as reference. These were then adjusted for confounding factors for a multivariate analysis. P < 0.05 were considered statistically significant. Univariate analysis demonstrated an association between coffee consumption and mortality, although this became insignificant on multivariate analysis. Coffee consumption, thus, does not seem to impact all-cause mortality or specific cardiovascular mortality. These findings do differ from those of recently published studies. Coffee consumption of any quantity seems to be safe without any increased mortality risk. There may be some protective effects but additional data are needed to further delineate this.

Univariate normalization of bispectrum using Hölder's inequality.

PubMed

Shahbazi, Forooz; Ewald, Arne; Nolte, Guido

2014-08-15

Considering that many biological systems including the brain are complex non-linear systems, suitable methods capable of detecting these non-linearities are required to study the dynamical properties of these systems. One of these tools is the third order cummulant or cross-bispectrum, which is a measure of interfrequency interactions between three signals. For convenient interpretation, interaction measures are most commonly normalized to be independent of constant scales of the signals such that its absolute values are bounded by one, with this limit reflecting perfect coupling. Although many different normalization factors for cross-bispectra were suggested in the literature these either do not lead to bounded measures or are themselves dependent on the coupling and not only on the scale of the signals. In this paper we suggest a normalization factor which is univariate, i.e., dependent only on the amplitude of each signal and not on the interactions between signals. Using a generalization of Hölder's inequality it is proven that the absolute value of this univariate bicoherence is bounded by zero and one. We compared three widely used normalizations to the univariate normalization concerning the significance of bicoherence values gained from resampling tests. Bicoherence values are calculated from real EEG data recorded in an eyes closed experiment from 10 subjects. The results show slightly more significant values for the univariate normalization but in general, the differences are very small or even vanishing in some subjects. Therefore, we conclude that the normalization factor does not play an important role in the bicoherence values with regard to statistical power, although a univariate normalization is the only normalization factor which fulfills all the required conditions of a proper normalization. Copyright © 2014 Elsevier B.V. All rights reserved.

Meta-analysis of quantitative pleiotropic traits for next-generation sequencing with multivariate functional linear models

PubMed Central

Chiu, Chi-yang; Jung, Jeesun; Chen, Wei; Weeks, Daniel E; Ren, Haobo; Boehnke, Michael; Amos, Christopher I; Liu, Aiyi; Mills, James L; Ting Lee, Mei-ling; Xiong, Momiao; Fan, Ruzong

2017-01-01

To analyze next-generation sequencing data, multivariate functional linear models are developed for a meta-analysis of multiple studies to connect genetic variant data to multiple quantitative traits adjusting for covariates. The goal is to take the advantage of both meta-analysis and pleiotropic analysis in order to improve power and to carry out a unified association analysis of multiple studies and multiple traits of complex disorders. Three types of approximate F -distributions based on Pillai–Bartlett trace, Hotelling–Lawley trace, and Wilks's Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants. Simulation analysis is performed to evaluate false-positive rates and power of the proposed tests. The proposed methods are applied to analyze lipid traits in eight European cohorts. It is shown that it is more advantageous to perform multivariate analysis than univariate analysis in general, and it is more advantageous to perform meta-analysis of multiple studies instead of analyzing the individual studies separately. The proposed models require individual observations. The value of the current paper can be seen at least for two reasons: (a) the proposed methods can be applied to studies that have individual genotype data; (b) the proposed methods can be used as a criterion for future work that uses summary statistics to build test statistics to meta-analyze the data. PMID:28000696

Meta-analysis of quantitative pleiotropic traits for next-generation sequencing with multivariate functional linear models.

PubMed

Chiu, Chi-Yang; Jung, Jeesun; Chen, Wei; Weeks, Daniel E; Ren, Haobo; Boehnke, Michael; Amos, Christopher I; Liu, Aiyi; Mills, James L; Ting Lee, Mei-Ling; Xiong, Momiao; Fan, Ruzong

2017-02-01

To analyze next-generation sequencing data, multivariate functional linear models are developed for a meta-analysis of multiple studies to connect genetic variant data to multiple quantitative traits adjusting for covariates. The goal is to take the advantage of both meta-analysis and pleiotropic analysis in order to improve power and to carry out a unified association analysis of multiple studies and multiple traits of complex disorders. Three types of approximate F -distributions based on Pillai-Bartlett trace, Hotelling-Lawley trace, and Wilks's Lambda are introduced to test for association between multiple quantitative traits and multiple genetic variants. Simulation analysis is performed to evaluate false-positive rates and power of the proposed tests. The proposed methods are applied to analyze lipid traits in eight European cohorts. It is shown that it is more advantageous to perform multivariate analysis than univariate analysis in general, and it is more advantageous to perform meta-analysis of multiple studies instead of analyzing the individual studies separately. The proposed models require individual observations. The value of the current paper can be seen at least for two reasons: (a) the proposed methods can be applied to studies that have individual genotype data; (b) the proposed methods can be used as a criterion for future work that uses summary statistics to build test statistics to meta-analyze the data.

Differentiation of nonneoplastic and neoplastic gallbladder polyps 1 cm or bigger with multi-detector row computed tomography.

PubMed

Park, Ko Woon; Kim, Seong Hyun; Choi, Seong Ho; Lee, Won Jae

2010-01-01

To evaluate useful computed tomographic features to differentiate nonneoplastic and neoplastic gallbladder polyps 1 cm or bigger. Thirty-one patients with 32 nonneoplastic polyps and 67 patients with 73 neoplastic polyps 1 cm or bigger underwent unenhanced and dual-phase (arterial and portal venous phases) multi-detector row computed tomography. Gallbladder polyps were diagnosed by cholecystectomy. Computed tomographic features including size (1.5 cm), surface (smooth or irregular), shape (pedunculated or sessile), accompanying wall thickening, basal indentation, perception on unenhanced images, and enhancement pattern between 2 groups were compared using univariate and multivariate analyses. On univariate analysis, age 55 years or older (P = 0.0019), size bigger than 1.5 cm (P < 0.0001), irregular surface (P = 0.0033), sessile shape (P = 0.0016), accompanying wall thickening (P = 0.0056), basal indentation (P = 0.0236), and perception on unenhanced images (P < 0.0001) were significantly more frequent in neoplastic polyps as compared with nonneoplastic polyps. On multivariate analysis, size bigger than 1.5 cm (P = 0.0260), sessile shape (P = 0.0397), and perception on unenhanced images (P < 0.0001) were statistically significant. Size bigger than 1.5 cm, sessile shape, and perception on unenhanced images are the main factors that differentiate neoplastic from nonneoplastic gallbladder polyps 1 cm or bigger.

Risk Factors Related with Retroperitoneal Laparoscopic Converted to Open Nephrectomy for Nonfunctioning Renal Tuberculosis.

PubMed

Xu, Bo; Hu, Jinghai; Chen, Anxiang; Hao, Yuanyuan; Liu, GuoHui; Wang, Chunxi; Wang, Xiaoqing

2017-06-01

The present study was designed to investigate the risk factors affecting the conversion to open surgery in retroperitoneal laparoscopic nephrectomy of nonfunctioning renal tuberculosis (TB). The records of 144 patients who underwent a retroperitoneal laparoscopic nephrectomy procedure by a single surgeon were retrospectively reviewed. The following factors, including age, sex, body mass index (BMI), diabetes status, hypertension status, side of kidney, size of kidney, degree of calcification, mild perirenal extravasation, contralateral hydronephrosis, the time of anti-TB, and surgeon experience were analyzed. Univariate and multivariate logistic regression analyses were used for statistical assessment. Twenty-three patients were converted to open surgery and the conversion rate was 15.97%. In univariate analysis, BMI ≥35 kg/m 2 (p = 0.023), hypertension (p = 0.011), diabetes (p = 0.003), and kidney size (p = 0.032) were the main factors of conversion to open surgery. Sex, age, side, anti-TB time, calcification, mild extravasation, and surgeon experience were not significantly related. In multivariate regression analysis, BMI ≥35 kg/m 2 , hypertension, diabetes, and enlargement of kidney were the most important factors for conversion to open surgery. Depending on the results achieved by a single surgeon, BMI ≥30 kg/m 2 , diabetes, hypertension, and enlargement of kidney significantly increased the conversion risk in retroperitoneal laparoscopic nephrectomy for nonfunctioning renal TB.

Expression of miR-146a-5p in patients with intracranial aneurysms and its association with prognosis.

PubMed

Zhang, H-L; Li, L; Cheng, C-J; Sun, X-C

2018-02-01

The study aims to detect the association of miR-146a-5p with intracranial aneurysms (IAs). The expression of miR-146a-5p was compared from plasma samples between 72 patients with intracranial aneurysms (IAs) and 40 healthy volunteers by quantitative Real-time polymerase chain reaction (qRT-PCR). Statistical analysis was performed to analyze the relationship between miR-146a-5p expression and clinical data and overall survival (OS) time of IAs patients. Univariate and multivariate Cox proportional hazards have also been performed. Notably, higher miR-146a-5p expression was found in plasma samples from 72 patients with intracranial aneurysms (IAs) compared with 40 healthy controls. Higher miR-146a-5p expression was significantly associated with rupture and Hunt-Hess level in IAs patients. Kaplan-Meier survival analysis verified that higher miR-146a-5p expression predicted a shorter overall survival (OS) compared with lower miR-146a-5p expression in IAs patients. Univariate and multivariate Cox proportional hazards demonstrated that higher miR-146a-5p expression, rupture, and Hunt-Hess were independent risk factors of OS in patients with intracranial aneurysms (IAs). MiR-146a-5p expression may serve as a biomarker for predicting prognosis in patients with IAs.

Mandibular osteoradionecrosis in squamous cell carcinoma of the oral cavity and oropharynx: incidence and risk factors.

PubMed

Monnier, Yan; Broome, Martin; Betz, Michael; Bouferrache, Kahina; Ozsahin, Mahmut; Jaques, Bertrand

2011-05-01

Mandibular osteoradionecrosis (ORN) is a serious complication of radiotherapy (RT) in head and neck cancer patients. The aim of this study was to analyze the incidence of and risk factors for mandibular ORN in squamous cell carcinoma (SCC) of the oral cavity and oropharynx. Case series with chart review. University tertiary care center for head and neck oncology. Seventy-three patients treated for stage I to IV SCC of the oral cavity and oropharynx between 2000 and 2007, with a minimum follow-up of 2 years, were included in the study. Treatment modalities included both RT with curative intent and adjuvant RT following tumor surgery. The log-rank test and Cox model were used for univariate and multivariate analyses. The incidence of mandibular ORN was 40% at 5 years. Using univariate analysis, the following risk factors were identified: oral cavity tumors (P < .01), bone invasion (P < .02), any surgery prior to RT (P < .04), and bone surgery (P < .0001). By multivariate analysis, mandibular surgery proved to be the most important risk factor and the only one reaching statistical significance (P < .0002). Mandibular ORN is a frequent long-term complication of RT for oral cavity and oropharynx cancers. Mandibular surgery before irradiation is the only independent risk factor. These aspects must be considered when planning treatment for these tumors.

Analysis of Exhaled Breath Volatile Organic Compounds in Inflammatory Bowel Disease: A Pilot Study.

PubMed

Hicks, Lucy C; Huang, Juzheng; Kumar, Sacheen; Powles, Sam T; Orchard, Timothy R; Hanna, George B; Williams, Horace R T

2015-09-01

Distinguishing between the inflammatory bowel diseases [IBD], Crohn's disease [CD] and ulcerative colitis [UC], is important for determining management and prognosis. Selected ion flow tube mass spectrometry [SIFT-MS] may be used to analyse volatile organic compounds [VOCs] in exhaled breath: these may be altered in disease states, and distinguishing breath VOC profiles can be identified. The aim of this pilot study was to identify, quantify, and analyse VOCs present in the breath of IBD patients and controls, potentially providing insights into disease pathogenesis and complementing current diagnostic algorithms. SIFT-MS breath profiling of 56 individuals [20 UC, 18 CD, and 18 healthy controls] was undertaken. Multivariate analysis included principal components analysis and partial least squares discriminant analysis with orthogonal signal correction [OSC-PLS-DA]. Receiver operating characteristic [ROC] analysis was performed for each comparative analysis using statistically significant VOCs. OSC-PLS-DA modelling was able to distinguish both CD and UC from healthy controls and from one other with good sensitivity and specificity. ROC analysis using combinations of statistically significant VOCs [dimethyl sulphide, hydrogen sulphide, hydrogen cyanide, ammonia, butanal, and nonanal] gave integrated areas under the curve of 0.86 [CD vs healthy controls], 0.74 [UC vs healthy controls], and 0.83 [CD vs UC]. Exhaled breath VOC profiling was able to distinguish IBD patients from controls, as well as to separate UC from CD, using both multivariate and univariate statistical techniques. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil

PubMed Central

Lankadurai, Brian P.; Furdui, Vasile I.; Reiner, Eric J.; Simpson, André J.; Simpson, Myrna J.

2013-01-01

1H NMR-based metabolomics was used to measure the response of Eisenia fetida earthworms after exposure to sub-lethal concentrations of perfluorooctane sulfonate (PFOS) in soil. Earthworms were exposed to a range of PFOS concentrations (five, 10, 25, 50, 100 or 150 mg/kg) for two, seven and fourteen days. Earthworm tissues were extracted and analyzed by 1H NMR. Multivariate statistical analysis of the metabolic response of E. fetida to PFOS exposure identified time-dependent responses that were comprised of two separate modes of action: a non-polar narcosis type mechanism after two days of exposure and increased fatty acid oxidation after seven and fourteen days of exposure. Univariate statistical analysis revealed that 2-hexyl-5-ethyl-3-furansulfonate (HEFS), betaine, leucine, arginine, glutamate, maltose and ATP are potential indicators of PFOS exposure, as the concentrations of these metabolites fluctuated significantly. Overall, NMR-based metabolomic analysis suggests elevated fatty acid oxidation, disruption in energy metabolism and biological membrane structure and a possible interruption of ATP synthesis. These conclusions obtained from analysis of the metabolic profile in response to sub-lethal PFOS exposure indicates that NMR-based metabolomics is an excellent discovery tool when the mode of action (MOA) of contaminants is not clearly defined. PMID:24958147

Methods for meta-analysis of multiple traits using GWAS summary statistics.

PubMed

Ray, Debashree; Boehnke, Michael

2018-03-01

Genome-wide association studies (GWAS) for complex diseases have focused primarily on single-trait analyses for disease status and disease-related quantitative traits. For example, GWAS on risk factors for coronary artery disease analyze genetic associations of plasma lipids such as total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides (TGs) separately. However, traits are often correlated and a joint analysis may yield increased statistical power for association over multiple univariate analyses. Recently several multivariate methods have been proposed that require individual-level data. Here, we develop metaUSAT (where USAT is unified score-based association test), a novel unified association test of a single genetic variant with multiple traits that uses only summary statistics from existing GWAS. Although the existing methods either perform well when most correlated traits are affected by the genetic variant in the same direction or are powerful when only a few of the correlated traits are associated, metaUSAT is designed to be robust to the association structure of correlated traits. metaUSAT does not require individual-level data and can test genetic associations of categorical and/or continuous traits. One can also use metaUSAT to analyze a single trait over multiple studies, appropriately accounting for overlapping samples, if any. metaUSAT provides an approximate asymptotic P-value for association and is computationally efficient for implementation at a genome-wide level. Simulation experiments show that metaUSAT maintains proper type-I error at low error levels. It has similar and sometimes greater power to detect association across a wide array of scenarios compared to existing methods, which are usually powerful for some specific association scenarios only. When applied to plasma lipids summary data from the METSIM and the T2D-GENES studies, metaUSAT detected genome-wide significant loci beyond the ones identified by univariate analyses. Evidence from larger studies suggest that the variants additionally detected by our test are, indeed, associated with lipid levels in humans. In summary, metaUSAT can provide novel insights into the genetic architecture of a common disease or traits. © 2017 WILEY PERIODICALS, INC.

Use of the Analysis of the Volatile Faecal Metabolome in Screening for Colorectal Cancer

PubMed Central

2015-01-01

Diagnosis of colorectal cancer is an invasive and expensive colonoscopy, which is usually carried out after a positive screening test. Unfortunately, existing screening tests lack specificity and sensitivity, hence many unnecessary colonoscopies are performed. Here we report on a potential new screening test for colorectal cancer based on the analysis of volatile organic compounds (VOCs) in the headspace of faecal samples. Faecal samples were obtained from subjects who had a positive faecal occult blood sample (FOBT). Subjects subsequently had colonoscopies performed to classify them into low risk (non-cancer) and high risk (colorectal cancer) groups. Volatile organic compounds were analysed by selected ion flow tube mass spectrometry (SIFT-MS) and then data were analysed using both univariate and multivariate statistical methods. Ions most likely from hydrogen sulphide, dimethyl sulphide and dimethyl disulphide are statistically significantly higher in samples from high risk rather than low risk subjects. Results using multivariate methods show that the test gives a correct classification of 75% with 78% specificity and 72% sensitivity on FOBT positive samples, offering a potentially effective alternative to FOBT. PMID:26086914

Prolonged Instability Prior to a Regime Shift | Science ...

EPA Pesticide Factsheets

Regime shifts are generally defined as the point of ‘abrupt’ change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia. This manuscript explores various methods of assessing the transition between alternative states in an ecological system described by a long-term high-resolution paleoecological dataset.

Uncertainty Analysis of Instrument Calibration and Application

NASA Technical Reports Server (NTRS)

Tripp, John S.; Tcheng, Ping

1999-01-01

Experimental aerodynamic researchers require estimated precision and bias uncertainties of measured physical quantities, typically at 95 percent confidence levels. Uncertainties of final computed aerodynamic parameters are obtained by propagation of individual measurement uncertainties through the defining functional expressions. In this paper, rigorous mathematical techniques are extended to determine precision and bias uncertainties of any instrument-sensor system. Through this analysis, instrument uncertainties determined through calibration are now expressed as functions of the corresponding measurement for linear and nonlinear univariate and multivariate processes. Treatment of correlated measurement precision error is developed. During laboratory calibration, calibration standard uncertainties are assumed to be an order of magnitude less than those of the instrument being calibrated. Often calibration standards do not satisfy this assumption. This paper applies rigorous statistical methods for inclusion of calibration standard uncertainty and covariance due to the order of their application. The effects of mathematical modeling error on calibration bias uncertainty are quantified. The effects of experimental design on uncertainty are analyzed. The importance of replication is emphasized, techniques for estimation of both bias and precision uncertainties using replication are developed. Statistical tests for stationarity of calibration parameters over time are obtained.

Pretreatment Health Behaviors Predict Survival Among Patients With Head and Neck Squamous Cell Carcinoma

PubMed Central

Duffy, Sonia A.; Ronis, David L.; McLean, Scott; Fowler, Karen E.; Gruber, Stephen B.; Wolf, Gregory T.; Terrell, Jeffrey E.

2009-01-01

Purpose Our prior work has shown that the health behaviors of head and neck cancer patients are interrelated and are associated with quality of life; however, other than smoking, the relationship between health behaviors and survival is unclear. Patients and Methods A prospective cohort study was conducted to determine the relationship between five pretreatment health behaviors (smoking, alcohol, diet, physical activity, and sleep) and all-cause survival among 504 head and neck cancer patients. Results Smoking status was the strongest predictor of survival, with both current smokers (hazard ratio [HR] = 2.4; 95% CI, 1.3 to 4.4) and former smokers (HR = 2.0; 95% CI, 1.2 to 3.5) showing significant associations with poor survival. Problem drinking was associated with survival in the univariate analysis (HR = 1.4; 95% CI, 1.0 to 2.0) but lost significance when controlling for other factors. Low fruit intake was negatively associated with survival in the univariate analysis only (HR = 1.6; 95% CI, 1.1 to 2.1), whereas vegetable intake was not significant in either univariate or multivariate analyses. Although physical activity was associated with survival in the univariate analysis (HR = 0.95; 95% CI, 0.93 to 0.97), it was not significant in the multivariate model. Sleep was not significantly associated with survival in either univariate or multivariate analysis. Control variables that were also independently associated with survival in the multivariate analysis were age, education, tumor site, cancer stage, and surgical treatment. Conclusion Variation in selected pretreatment health behaviors (eg, smoking, fruit intake, and physical activity) in this population is associated with variation in survival. PMID:19289626

Application and validation of Cox regression models in a single-center series of double kidney transplantation.

PubMed

Santori, G; Fontana, I; Bertocchi, M; Gasloli, G; Magoni Rossi, A; Tagliamacco, A; Barocci, S; Nocera, A; Valente, U

2010-05-01

A useful approach to reduce the number of discarded marginal kidneys and to increase the nephron mass is double kidney transplantation (DKT). In this study, we retrospectively evaluated the potential predictors for patient and graft survival in a single-center series of 59 DKT procedures performed between April 21, 1999, and September 21, 2008. The kidney recipients of mean age 63.27 +/- 5.17 years included 16 women (27%) and 43 men (73%). The donors of mean age 69.54 +/- 7.48 years included 32 women (54%) and 27 men (46%). The mean posttransplant dialysis time was 2.37 +/- 3.61 days. The mean hospitalization was 20.12 +/- 13.65 days. Average serum creatinine (SCr) at discharge was 1.5 +/- 0.59 mg/dL. In view of the limited numbers of recipient deaths (n = 4) and graft losses (n = 8) that occurred in our series, the proportional hazards assumption for each Cox regression model with P < .05 was tested by using correlation coefficients between transformed survival times and scaled Schoenfeld residuals, and checked with smoothed plots of Schoenfeld residuals. For patient survival, the variables that reached statistical significance were donor SCr (P = .007), donor creatinine cleararance (P = .023), and recipient age (P = .047). Each significant model passed the Schoenfeld test. By entering these variables into a multivariate Cox model for patient survival, no further significance was observed. In the univariate Cox models performed for graft survival, statistical significance was noted for donor SCr (P = .027), SCr 3 months post-DKT (P = .043), and SCr 6 months post-DKT (P = .017). All significant univariate models for graft survival passed the Schoenfeld test. A final multivariate model retained SCr at 6 months (beta = 1.746, P = .042) and donor SCr (beta = .767, P = .090). In our analysis, SCr at 6 months seemed to emerge from both univariate and multivariate Cox models as a potential predictor of graft survival among DKT. Multicenter studies with larger recipient populations and more graft losses should be performed to confirm our findings. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Prognostic value of echocardiographic indices of left atrial morphology and function in dogs with myxomatous mitral valve disease

PubMed Central

Romito, Giovanni; Guglielmini, Carlo; Diana, Alessia; Pelle, Nazzareno G.; Contiero, Barbara; Cipone, Mario

2018-01-01

Background The prognostic relevance of left atrial (LA) morphological and functional variables, including those derived from speckle tracking echocardiography (STE), has been little investigated in veterinary medicine. Objectives To assess the prognostic value of several echocardiographic variables, with a focus on LA morphological and functional variables in dogs with myxomatous mitral valve disease (MMVD). Animals One‐hundred and fifteen dogs of different breeds with MMVD. Methods Prospective cohort study. Conventional morphologic and echo‐Doppler variables, LA areas and volumes, and STE‐based LA strain analysis were performed in all dogs. A survival analysis was performed to test for the best echocardiographic predictors of cardiac‐related death. Results Most of the tested variables, including all LA STE‐derived variables were univariate predictors of cardiac death in Cox proportional hazard analysis. Because of strong correlation between many variables, only left atrium to aorta ratio (LA/Ao > 1.7), mitral valve E wave velocity (MV E vel > 1.3 m/s), LA maximal volume (LAVmax > 3.53 mL/kg), peak atrial longitudinal strain (PALS < 30%), and contraction strain index (CSI per 1% increase) were entered in the univariate analysis, and all were predictors of cardiac death. However, only the MV E vel (hazard ratio [HR], 4.45; confidence interval [CI], 1.76‐11.24; P < .001) and LAVmax (HR, 2.32; CI, 1.10‐4.89; P = .024) remained statistically significant in the multivariable analysis. Conclusions and Clinical Importance The assessment of LA dimension and function provides useful prognostic information in dogs with MMVD. Considering all the LA variables, LAVmax appears the strongest predictor of cardiac death, being superior to LA/Ao and STE‐derived variables. PMID:29572938

Dose-volume effects in pathologic lymph nodes in locally advanced cervical cancer.

PubMed

Bacorro, Warren; Dumas, Isabelle; Escande, Alexandre; Gouy, Sebastien; Bentivegna, Enrica; Morice, Philippe; Haie-Meder, Christine; Chargari, Cyrus

2018-03-01

In cervical cancer patients, dose-volume relationships have been demonstrated for tumor and organs-at-risk, but not for pathologic nodes. The nodal control probability (NCP) according to dose/volume parameters was investigated. Patients with node-positive cervical cancer treated curatively with external beam radiotherapy (EBRT) and image-guided brachytherapy (IGABT) were identified. Nodal doses during EBRT, IGABT and boost were converted to 2-Gy equivalent (α/β = 10 Gy) and summed. Pathologic nodes were followed individually from diagnosis to relapse. Statistical analyses comprised log-rank tests (univariate analyses), Cox proportional model (factors with p ≤ 0.1 in univariate) and Probit analyses. A total of 108 patients with 254 unresected pathological nodes were identified. The mean nodal volume at diagnosis was 3.4 ± 5.8 cm 3 . The mean total nodal EQD2 doses were 55.3 ± 5.6 Gy. Concurrent chemotherapy was given in 96%. With a median follow-up of 33.5 months, 20 patients (18.5%) experienced relapse in nodes considered pathologic at diagnosis. Overall nodal recurrence rate was 9.1% (23/254). On univariate analyses, nodal volume (threshold: 3 cm 3 , p < .0001) and lymph node dose (≥57.5 Gy α/β10 , p = .039) were significant for nodal control. The use of simultaneous boost was borderline for significance (p = .07). On multivariate analysis, volume (HR = 8.2, 4.0-16.6, p < .0001) and dose (HR = 2, 1.05-3.9, p = .034) remained independent factors. Probit analysis combining dose and volume showed significant relationships with NCP, with increasing gap between the curves with higher nodal volumes. A nodal dose-volume effect on NCP is demonstrated for the first time, with increasing NCP benefit of additional doses to higher-volume nodes. Copyright © 2018 Elsevier Inc. All rights reserved.

Role of late gadolinium enhancement cardiovascular magnetic resonance in the risk stratification of hypertrophic cardiomyopathy.

PubMed

Ismail, Tevfik F; Jabbour, Andrew; Gulati, Ankur; Mallorie, Amy; Raza, Sadaf; Cowling, Thomas E; Das, Bibek; Khwaja, Jahanzaib; Alpendurada, Francisco D; Wage, Ricardo; Roughton, Michael; McKenna, William J; Moon, James C; Varnava, Amanda; Shakespeare, Carl; Cowie, Martin R; Cook, Stuart A; Elliott, Perry; O'Hanlon, Rory; Pennell, Dudley J; Prasad, Sanjay K

2014-12-01

Myocardial fibrosis identified by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM) is associated with adverse cardiovascular events, but its value as an independent risk factor for sudden cardiac death (SCD) is unknown. We investigated the role of LGE-CMR in the risk stratification of HCM. We conducted a prospective cohort study in a tertiary referral centre. Consecutive patients with HCM (n=711, median age 56.3 years, IQR 46.7-66.6; 70.0% male) underwent LGE-CMR and were followed for a median 3.5 years. The primary end point was SCD or aborted SCD. Overall, 471 patients (66.2%) had myocardial fibrosis (median 5.9% of left ventricular mass, IQR: 2.2-13.3). Twenty-two (3.1%) reached the primary end point. The extent but not the presence of fibrosis was a significant univariable predictor of the primary end point (HR per 5% LGE: 1.24, 95% CI 1.06 to 1.45; p=0.007 and HR for LGE: 2.69, 95% CI 0.91 to 7.97; p=0.073, respectively). However, on multivariable analysis, only LV-EF remained statistically significant (HR: 0.92, 95% CI 0.89 to 0.95; p<0.001). For the secondary outcome of cardiovascular mortality/aborted SCD, the presence and the amount of fibrosis were significant predictors on univariable but not multivariable analysis after adjusting for LV-EF and non-sustained ventricular tachycardia. The amount of myocardial fibrosis was a strong univariable predictor of SCD risk. However, this effect was not maintained after adjusting for LV-EF. Further work is required to elucidate the interrelationship between fibrosis and traditional predictors of outcome in HCM. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Statistical Frequency-Dependent Analysis of Trial-to-Trial Variability in Single Time Series by Recurrence Plots.

PubMed

Tošić, Tamara; Sellers, Kristin K; Fröhlich, Flavio; Fedotenkova, Mariia; Beim Graben, Peter; Hutt, Axel

2015-01-01

For decades, research in neuroscience has supported the hypothesis that brain dynamics exhibits recurrent metastable states connected by transients, which together encode fundamental neural information processing. To understand the system's dynamics it is important to detect such recurrence domains, but it is challenging to extract them from experimental neuroscience datasets due to the large trial-to-trial variability. The proposed methodology extracts recurrent metastable states in univariate time series by transforming datasets into their time-frequency representations and computing recurrence plots based on instantaneous spectral power values in various frequency bands. Additionally, a new statistical inference analysis compares different trial recurrence plots with corresponding surrogates to obtain statistically significant recurrent structures. This combination of methods is validated by applying it to two artificial datasets. In a final study of visually-evoked Local Field Potentials in partially anesthetized ferrets, the methodology is able to reveal recurrence structures of neural responses with trial-to-trial variability. Focusing on different frequency bands, the δ-band activity is much less recurrent than α-band activity. Moreover, α-activity is susceptible to pre-stimuli, while δ-activity is much less sensitive to pre-stimuli. This difference in recurrence structures in different frequency bands indicates diverse underlying information processing steps in the brain.

Statistical Frequency-Dependent Analysis of Trial-to-Trial Variability in Single Time Series by Recurrence Plots

PubMed Central

Tošić, Tamara; Sellers, Kristin K.; Fröhlich, Flavio; Fedotenkova, Mariia; beim Graben, Peter; Hutt, Axel

2016-01-01

For decades, research in neuroscience has supported the hypothesis that brain dynamics exhibits recurrent metastable states connected by transients, which together encode fundamental neural information processing. To understand the system's dynamics it is important to detect such recurrence domains, but it is challenging to extract them from experimental neuroscience datasets due to the large trial-to-trial variability. The proposed methodology extracts recurrent metastable states in univariate time series by transforming datasets into their time-frequency representations and computing recurrence plots based on instantaneous spectral power values in various frequency bands. Additionally, a new statistical inference analysis compares different trial recurrence plots with corresponding surrogates to obtain statistically significant recurrent structures. This combination of methods is validated by applying it to two artificial datasets. In a final study of visually-evoked Local Field Potentials in partially anesthetized ferrets, the methodology is able to reveal recurrence structures of neural responses with trial-to-trial variability. Focusing on different frequency bands, the δ-band activity is much less recurrent than α-band activity. Moreover, α-activity is susceptible to pre-stimuli, while δ-activity is much less sensitive to pre-stimuli. This difference in recurrence structures in different frequency bands indicates diverse underlying information processing steps in the brain. PMID:26834580

A refined method for multivariate meta-analysis and meta-regression

PubMed Central

Jackson, Daniel; Riley, Richard D

2014-01-01

Making inferences about the average treatment effect using the random effects model for meta-analysis is problematic in the common situation where there is a small number of studies. This is because estimates of the between-study variance are not precise enough to accurately apply the conventional methods for testing and deriving a confidence interval for the average effect. We have found that a refined method for univariate meta-analysis, which applies a scaling factor to the estimated effects’ standard error, provides more accurate inference. We explain how to extend this method to the multivariate scenario and show that our proposal for refined multivariate meta-analysis and meta-regression can provide more accurate inferences than the more conventional approach. We explain how our proposed approach can be implemented using standard output from multivariate meta-analysis software packages and apply our methodology to two real examples. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:23996351

Academic Departments and Student Attitudes toward Different Dimensions of Web-based Education.

ERIC Educational Resources Information Center

Federico, Pat-Anthony

2001-01-01

Describes research at the Naval Postgraduate School that investigated student attitudes toward various aspects of Web-based instruction. Results of a survey, which were analyzed using a variety of multivariate and univariate statistical techniques, showed significantly different attitudes toward different dimensions of Web-based education…

Simultaneous calibration of ensemble river flow predictions over an entire range of lead times

NASA Astrophysics Data System (ADS)

Hemri, S.; Fundel, F.; Zappa, M.

2013-10-01

Probabilistic estimates of future water levels and river discharge are usually simulated with hydrologic models using ensemble weather forecasts as main inputs. As hydrologic models are imperfect and the meteorological ensembles tend to be biased and underdispersed, the ensemble forecasts for river runoff typically are biased and underdispersed, too. Thus, in order to achieve both reliable and sharp predictions statistical postprocessing is required. In this work Bayesian model averaging (BMA) is applied to statistically postprocess ensemble runoff raw forecasts for a catchment in Switzerland, at lead times ranging from 1 to 240 h. The raw forecasts have been obtained using deterministic and ensemble forcing meteorological models with different forecast lead time ranges. First, BMA is applied based on mixtures of univariate normal distributions, subject to the assumption of independence between distinct lead times. Then, the independence assumption is relaxed in order to estimate multivariate runoff forecasts over the entire range of lead times simultaneously, based on a BMA version that uses multivariate normal distributions. Since river runoff is a highly skewed variable, Box-Cox transformations are applied in order to achieve approximate normality. Both univariate and multivariate BMA approaches are able to generate well calibrated probabilistic forecasts that are considerably sharper than climatological forecasts. Additionally, multivariate BMA provides a promising approach for incorporating temporal dependencies into the postprocessed forecasts. Its major advantage against univariate BMA is an increase in reliability when the forecast system is changing due to model availability.

Self-confidence in financial analysis: a study of younger and older male professional analysts.

PubMed

Webster, R L; Ellis, T S

2001-06-01

Measures of reported self-confidence in performing financial analysis by 59 professional male analysts, 31 born between 1946 and 1964 and 28 born between 1965 and 1976, were investigated and reported. Self-confidence in one's ability is important in the securities industry because it affects recommendations and decisions to buy, sell, and hold securities. The respondents analyzed a set of multiyear corporate financial statements and reported their self-confidence in six separate financial areas. Data from the 59 male financial analysts were tallied and analyzed using both univariate and multivariate statistical tests. Rated self-confidence was not significantly different for the younger and the older men. These results are not consistent with a similar prior study of female analysts in which younger women showed significantly higher self-confidence than older women.

Univariate and Bivariate Loglinear Models for Discrete Test Score Distributions.

ERIC Educational Resources Information Center

Holland, Paul W.; Thayer, Dorothy T.

2000-01-01

Applied the theory of exponential families of distributions to the problem of fitting the univariate histograms and discrete bivariate frequency distributions that often arise in the analysis of test scores. Considers efficient computation of the maximum likelihood estimates of the parameters using Newton's Method and computationally efficient…

Game-Related Statistics that Discriminated Winning, Drawing and Losing Teams from the Spanish Soccer League

PubMed Central

Lago-Peñas, Carlos; Lago-Ballesteros, Joaquín; Dellal, Alexandre; Gómez, Maite

2010-01-01

The aim of the present study was to analyze men’s football competitions, trying to identify which game-related statistics allow to discriminate winning, drawing and losing teams. The sample used corresponded to 380 games from the 2008-2009 season of the Spanish Men’s Professional League. The game-related statistics gathered were: total shots, shots on goal, effectiveness, assists, crosses, offsides commited and received, corners, ball possession, crosses against, fouls committed and received, corners against, yellow and red cards, and venue. An univariate (t-test) and multivariate (discriminant) analysis of data was done. The results showed that winning teams had averages that were significantly higher for the following game statistics: total shots (p < 0.001), shots on goal (p < 0.01), effectiveness (p < 0.01), assists (p < 0.01), offsides committed (p < 0.01) and crosses against (p < 0.01). Losing teams had significantly higher averages in the variable crosses (p < 0.01), offsides received (p < 0. 01) and red cards (p < 0.01). Discriminant analysis allowed to conclude the following: the variables that discriminate between winning, drawing and losing teams were the total shots, shots on goal, crosses, crosses against, ball possession and venue. Coaches and players should be aware for these different profiles in order to increase knowledge about game cognitive and motor solicitation and, therefore, to evaluate specificity at the time of practice and game planning. Key points This paper increases the knowledge about soccer match analysis. Give normative values to establish practice and match objectives. Give applications ideas to connect research with coaches’ practice. PMID:24149698

Neurological Outcomes Following Suicidal Hanging: A Prospective Study of 101 Patients

PubMed Central

Jawaid, Mohammed Turab; Amalnath, S. Deepak; Subrahmanyam, D. K. S.

2017-01-01

Context: Survivors of suicidal hanging can have variable neurological outcomes – from complete recovery to irreversible brain damage. Literature on the neurological outcomes in these patients is confined to retrospective studies and case series. Hence, this prospective study was carried out. Aims: The aim is to study the neurological outcomes in suicidal hanging. Settings and Design: This was a prospective observational study carried out from July 2014 to July 2016. Subjects and Methods: Consecutive patients admitted to the emergency and medicine wards were included in the study. Details of the clinical and radiological findings, course in hospital and at 1 month postdischarge were analyzed. Statistical Analysis Used: Statistical analysis was performed using IBM SPSS advanced statistics 20.0 (SPSS Inc., Chicago, USA). Univariate analysis was performed using Chi-square test for significance and Odd's ratio was calculated. Results: Of the 101 patients, 6 died and 4 had residual neuro deficits. Cervical spine injury was seen in 3 patients. Interestingly, 39 patients could not remember the act of hanging (retrograde amnesia). Hypotension, pulmonary edema, Glasgow coma scale (GCS) score <8 at admission, need for mechanical ventilation, and cerebral edema on plain computed tomography were more in those with amnesia as compared to those with normal memory and these findings were statistically significant. Conclusions: Majority of patients recovered without any sequelae. Routine imaging of cervical spine may not be warranted in all patients, even in those with poor GCS. Retrograde amnesia might be more common than previously believed and further studies are needed to analyze this peculiar feature. PMID:28584409

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apte, A; Veeraraghavan, H; Oh, J

Purpose: To present an open source and free platform to facilitate radiomics research — The “Radiomics toolbox” in CERR. Method: There is scarcity of open source tools that support end-to-end modeling of image features to predict patient outcomes. The “Radiomics toolbox” strives to fill the need for such a software platform. The platform supports (1) import of various kinds of image modalities like CT, PET, MR, SPECT, US. (2) Contouring tools to delineate structures of interest. (3) Extraction and storage of image based features like 1st order statistics, gray-scale co-occurrence and zonesize matrix based texture features and shape features andmore » (4) Statistical Analysis. Statistical analysis of the extracted features is supported with basic functionality that includes univariate correlations, Kaplan-Meir curves and advanced functionality that includes feature reduction and multivariate modeling. The graphical user interface and the data management are performed with Matlab for the ease of development and readability of code and features for wide audience. Open-source software developed with other programming languages is integrated to enhance various components of this toolbox. For example: Java-based DCM4CHE for import of DICOM, R for statistical analysis. Results: The Radiomics toolbox will be distributed as an open source, GNU copyrighted software. The toolbox was prototyped for modeling Oropharyngeal PET dataset at MSKCC. The analysis will be presented in a separate paper. Conclusion: The Radiomics Toolbox provides an extensible platform for extracting and modeling image features. To emphasize new uses of CERR for radiomics and image-based research, we have changed the name from the “Computational Environment for Radiotherapy Research” to the “Computational Environment for Radiological Research”.« less

Factors affecting surgical margin recurrence after hepatectomy for colorectal liver metastases.

PubMed

Akyuz, Muhammet; Aucejo, Federico; Quintini, Cristiano; Miller, Charles; Fung, John; Berber, Eren

2016-06-01

Hepatic recurrence after resection of colorectal liver metastasis (CLM) occurs in 50% of patients during follow-up, with 2.8% to 13.9% presenting with surgical margin recurrence (SMR). The aim of this study is to analyze factors that related to SMR in patients with CLM undergoing hepatectomy. Demographics, clinical and survival data of patients who underwent hepatectomy were identified from a prospectively maintained, institutional review board (IRB)-approved database between 2000 and 2012. Statistical analysis was performed using univariate Kaplan Meier and Cox proportional hazard model. There were 85 female and 121 male patients who underwent liver resection for CLM. An R0 resection was performed in 157 (76%) patients and R1 resection in 49. SMR was detected in 32 patients (15.5%) followed up for a median of 29 months (range, 3-121 months). A half of these patients had undergone R1 (n=16) and another half R0 resection (n=16). Tumor size, preoperative carcinoembryonic antigen (CEA) level and margin status were associated with SMR on univariate analysis. On multivariate analysis, a positive surgical margin was the only independent predictor of SMR. The receipt of adjuvant chemotherapy did not affect margin recurrence. SMR was an independent risk factor associated with worse disease-free (DFS) and overall survival (OS). This study shows that SMR, which can be detected in up to 15.5% of patients after liver resection for CLM, adversely affects DFS and OS. The fact that a positive surgical margin was the only predictive factor for SMR in these patients underscores the importance of achieving negative margins during hepatectomy.

Prevention program for Clostridium difficile infection: a single-centre Serbian experience.

PubMed

Brkic, Snezana; Pellicano, Rinaldo; Turkulov, Vesna; Radovanovic, Marija; Abenavoli, Ludovico

2016-06-01

Clostridium difficile (C. difficile) diarrhea is a common, iatrogenic, nosocomial disease with a worldwide diffusion. Recent studies reported that the incidence of C. difficile infection (CDI) is rising, due to aging of the population and to greater prevalence of hypervirulent strains. We investigated whether the application of a prevention program lead to a decline in the incidence of intrahospital CDI. The study was designed as observational, to compare the efficacy of Schülke preventive program with the standard protocols, in a period of 4 months. For every patient with community-onset healthcare facility-associated (HCFA) CDI, we randomly selected four controls (1:4) with the same ICD code but without HCFA CDI. For statistical analysis the nonparametric, one-way ANOVA, univariate regression analysis, univariate analysis of variance, and Welch and Brown-Forsythe Test were used. Clinical features of HCFA CDI were typical. HCFA CDI group was significantly older than control group (P=0.008 and F=6.686; Partial Eta Square=0.013). Patients with HCFA CDI stayed significantly longer in hospital (P=0.000 and F=69.379; Partial Eta Square=0.117). Acquiring CDI prolonged the hospitalization of 14.52 days. HCFA CDI significantly increases the total cost of hospitalization as well as each element of the price respectively. With the application of the prevention program the annual incidence of CDI dropped from 49.01 in 2013 to 18.22/10000 bed days in 2014. Applying Schülke preventive program, implemented in 2014, has led to significant savings for the hospital compared to previous methods.

Post-traumatic stress disorder status in a rescue group after the Wenchuan earthquake relief

PubMed Central

Huang, Junhua; Liu, Qunying; Li, Jinliang; Li, Xuejiang; You, Jin; Zhang, Liang; Tian, Changfu; Luan, Rongsheng

2013-01-01

Previous studies have suggested that the incidence of post-traumatic stress disorder in earthquake rescue workers is relatively high. Risk factors for this disorder include demographic characteristics, earthquake-related high-risk factors, risk factors in the rescue process, personality, social support and coping style. This study examined the current status of a unit of 1 040 rescue workers who participated in earthquake relief for the Wenchuan earthquake that occurred on May 12th, 2008. Post-traumatic stress disorder was diagnosed primarily using the Clinician-Administered Post-traumatic Stress Disorder Scale during structured interviews. Univariate and multivariate statistical analyses were used to examine major risk factors that contributed to the incidence of post-traumatic stress disorder. Results revealed that the incidence of this disorder in the rescue group was 5.96%. The impact factors in univariate analysis included death of family members, contact with corpses or witnessing of the deceased or seriously injured, near-death experience, severe injury or mental trauma in the rescue process and working at the epicenter of the earthquake. Correlation analysis suggested that post-traumatic stress disorder was positively correlated with psychotic and neurotic personalities, negative coping and low social support. Impact factors in multivariate logistic regression analysis included near-death experience, severe injury or mental trauma, working in the epicenter of the rescue, neurotic personality, negative coping and low social support, among which low social support had the largest odds ratio of 20.42. Findings showed that the occurrence of post-traumatic stress disorder was the result of the interaction of multiple factors. PMID:25206499

Transforming Parent-Child Interaction in Family Routines: Longitudinal Analysis with Families of Children with Developmental Disabilities.

PubMed

Lucyshyn, Joseph M; Fossett, Brenda; Bakeman, Roger; Cheremshynski, Christy; Miller, Lynn; Lohrmann, Sharon; Binnendyk, Lauren; Khan, Sophia; Chinn, Stephen; Kwon, Samantha; Irvin, Larry K

2015-12-01

The efficacy and consequential validity of an ecological approach to behavioral intervention with families of children with developmental disabilities was examined. The approach aimed to transform coercive into constructive parent-child interaction in family routines. Ten families participated, including 10 mothers and fathers and 10 children 3-8 years old with developmental disabilities. Thirty-six family routines were selected (2 to 4 per family). Dependent measures included child problem behavior, routine steps completed, and coercive and constructive parent-child interaction. For each family, a single case, multiple baseline design was employed with three phases: baseline, intervention, and follow-up. Visual analysis evaluated the functional relation between intervention and improvements in child behavior and routine participation. Nonparametric tests across families evaluated the statistical significance of these improvements. Sequential analyses within families and univariate analyses across families examined changes from baseline to intervention in the percentage and odds ratio of coercive and constructive parent-child interaction. Multiple baseline results documented functional or basic effects for 8 of 10 families. Nonparametric tests showed these changes to be significant. Follow-up showed durability at 11 to 24 months postintervention. Sequential analyses documented the transformation of coercive into constructive processes for 9 of 10 families. Univariate analyses across families showed significant improvements in 2- and 4-step coercive and constructive processes but not in odds ratio. Results offer evidence of the efficacy of the approach and consequential validity of the ecological unit of analysis, parent-child interaction in family routines. Future studies should improve efficiency, and outcomes for families experiencing family systems challenges.

Retrospective study of adjuvant icotinib in postoperative lung cancer patients harboring epidermal growth factor receptor mutations.

PubMed

Yao, Shuyang; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu; Zhang, Yi

2016-09-01

Epidermal growth factor receptor (EGFR) mutations occur in about 50% of Asian patients with non-small cell lung cancer (NSCLC). Patients with advanced NSCLC and EGFR mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors (TKIs). This study assessed the efficacy and safety of adjuvant icotinib without chemotherapy in EGFR-mutated NSCLC patients undergoing resection of stage IB-IIIA. Our retrospective study enrolled 20 patients treated with icotinib as adjuvant therapy. Survival factors were evaluated by univariate and Cox regression analysis. The median follow-up time was 30 months (range 24-41). At the data cut-off, five patients (25%) had recurrence or metastasis and one patient had died of the disease. The two-year disease-free survival (DFS) rate was 85%. No recurrence occurred in the high-risk stage IB subgroup during the follow-up period. In univariate analysis, the micropapillary pattern had a statistically significant effect on DFS ( P = 0.040). Multivariate logistic regression analysis showed that there was no independent predictor. Drug related adverse events (AEs) occurred in nine patients (45.0%). The most common AEs were skin-related events and diarrhea, but were relatively mild. No grade 3 AEs or occurrences of intolerable toxicity were observed. Icotinib as adjuvant therapy is effective in patients harboring EGFR mutations after complete resection, with an acceptable AE profile. Further trials with larger sample sizes might confirm the efficiency of adjuvant TKI in selected patients. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Predictive factors of Gastrointestinal motility Dysfunction after gastrojejunostomy for peptic ulcer stenosis.

PubMed

Ayadi, Sofiene; Daghfous, Amine; Saidani, Ahmed; Haddad, Anis; Magherbi, Houcine; Jouini, Mohamed; Kacem, Montassar; Ben Safta, Zoubeir

2014-10-01

Despite the establishment of effective medical therapies in peptic ulcer disease, gastric outlet obstruction remains one of the most common health problem in Tunisia. Various operations have been attempted, which may lead to postoperative morbidity. Gastrointestinal (GI) motility dysfunction is the most common complications. to determine the predictive factor of gastrointestinal motility dysfunction after gastrojejunostomy for peptic ulcer stenosis. We carried out a retrospective study to evaluate the postoperative recovery of the motility of the upper gastrointestinal tract after gastrojejunostomy for peptic ulcer stenosis. During the 9- year study, 138 patients underwent operations for ulcer peptic stenosis. Among the patients, 116 (84,1%) were treated with gastrojejunostomy. Descriptive statistics, univariate and multivariate analyses were performed. The mean age of patients was 47.85 years (range: 19- 92years) and most. Were male (84, 5 %). Ninety two (79.3%) patients had a documented history of peptic ulcer disease. The duration of symptoms ranged from 10 to 372 days (mean: 135.86 days). Eighty two (71%) patients were operated on through laparotomy. Laparoscopic procedure was performed in 29% of the patients. There was no operative mortality. Perioperative morbidity occurred in 12.4% (14 patients). Gastrointestinal motility dysfunction occurred in 12 patients (10.3%). It was treated by nasogastric aspiration and prokinetics. By univariate analysis; diabetes (0,010), cachexia (0,049), ASA class (0.05) were all statistically associated with gastrointestinal motility dysfunction in this series. Multivariate logistic regression analysis (table 2) showed that the cachexia (0,009), ASA class (0.02) were the main predictors of gastrointestinal motility dysfunction after gastrojejunostomy for peptic ulcer stenosis in the followed patients. Gastrointestinal motility dysfunction is the most common complications after gastrojejunostomy for pyloric adult stenosis. Surgery must be preceded by careful medical preparation. It is more likely to occur in patients with an ASA class 2 or greater. Those patients should be considered for other treatment options, such as endoscopic balloon dilation.

Age-dependent risk factors for malnutrition in traumatology and orthopedic patients.

PubMed

Lambert, Christine; Nüssler, Andreas; Biesalski, Hans Konrad; Freude, Thomas; Bahrs, Christian; Ochs, Gunnar; Flesch, Ingo; Stöckle, Ulrich; Ihle, Christoph

2017-05-01

The aim of this study was to investigate the prevalence of risk of malnutrition (RoM) in an orthopedic and traumatology patient cohort with a broad range of ages. In addition to the classical indicators for risk assessment (low body mass index, weight loss, and comorbidity), this study aimed to analyze the effects of lifestyle factors (eating pattern, smoking, physical activity) on RoM. The prospective cohort study included 1053 patients in a level 1 trauma center in Germany. RoM was assessed by Nutritional Risk Screening (NRS) 2002 and for the elderly additionally by Mini Nutritional Assessment (MNA). Age-dependent risk factors identified in univariate statistical analysis were used for multivariate logistic regression models. The prevalence of patients at RoM (NRS ≥3) was 22%. In the three age categories (<50 y, 50-69 y, and ≥70 y), loss of appetite, weight loss, number of comorbidities, drugs and gastrointestinal symptoms significantly increased RoM in univariate statistical analysis. In patients ages ≥70 y, several disease- and lifestyle-related factors (not living at home, less frequent consumption of vegetables and whole meal bread, low physical activity, and smoking) were associated with RoM. Multivariate logistic regression model for the total study population identified weight loss (odds ratio [OR], 6.09; 95% confidence interval [CI], 4.14-8.83), loss of appetite (OR, 3.81; 95% CI, 2.52-5.78), age-specific low BMI (OR, 1.87; 95% CI, 1.18-2.97), number of drugs taken (OR, 1.19; 95% CI, 1.12-1.26), age (OR, 1.03; 95% CI, 1.02-1.04), and days per week with vegetable consumption (OR, 0.938; 95% CI, 0.89-0.99) as risk factors. Malnutrition in trauma and orthopedic patients is not only a problem related to age. Lifestyle-related factors also contribute significantly to malnutrition in geriatric patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Boundary formulations for sensitivity analysis without matrix derivatives

NASA Technical Reports Server (NTRS)

Kane, J. H.; Guru Prasad, K.

1993-01-01

A new hybrid approach to continuum structural shape sensitivity analysis employing boundary element analysis (BEA) is presented. The approach uses iterative reanalysis to obviate the need to factor perturbed matrices in the determination of surface displacement and traction sensitivities via a univariate perturbation/finite difference (UPFD) step. The UPFD approach makes it possible to immediately reuse existing subroutines for computation of BEA matrix coefficients in the design sensitivity analysis process. The reanalysis technique computes economical response of univariately perturbed models without factoring perturbed matrices. The approach provides substantial computational economy without the burden of a large-scale reprogramming effort.

The prognostic significance of nonsentinel lymph node metastasis in melanoma.

PubMed

Brown, Russell E; Ross, Merrick I; Edwards, Michael J; Noyes, R Dirk; Reintgen, Douglas S; Hagendoorn, Lee J; Stromberg, Arnold J; Martin, Robert C G; McMasters, Kelly M; Scoggins, Charles R

2010-12-01

We hypothesized that metastasis beyond the sentinel lymph nodes (SLN) to the nonsentinel nodes (NSN) is an important predictor of survival. Analysis was performed of a prospective multi-institutional study that included patients with melanoma ≥ 1.0 mm in Breslow thickness. All patients underwent SLN biopsy; completion lymphadenectomy was performed for all SLN metastases. Disease-free survival (DFS) and overall survival (OS) were computed by Kaplan-Meier analysis; univariate and multivariate analyses were performed to identify factors associated with differences in survival among groups. A total of 2335 patients were analyzed over a median follow-up of 68 months. We compared 3 groups: SLN negative (n = 1988), SLN-only positive (n = 296), and both SLN and NSN positive (n = 51). The 5-year DFS rates were 85.5, 64.8, and 42.6% for groups 1, 2, and 3, respectively (P < 0.001). The 5-year OS rates were 85.5, 64.9, and 49.4%, respectively (P < 0.001). On univariate analysis, predictors of decreased OS included: SLN metastasis, NSN metastasis, increased total number of positive LN, increased ratio of positive LN to total LN, increased age, male gender, increased Breslow thickness, presence of ulceration, Clark level ≥ IV, and axial primary site (in all cases, P < 0.01). When the total number of positive LN and NSN status were evaluated using multivariate analysis, NSN status remained statistically significant (P < 0.01), while the total number of positive LN and LN ratio did not. NSN melanoma metastasis is an independent prognostic factor for DFS and OS, which is distinct from the number of positive lymph nodes or the lymph node ratio.

Positron emission tomography–computed tomography predictors of progression after DA-R-EPOCH for PMBCL

PubMed Central

Ng, Andrea K.; Dabaja, Bouthaina S.; Milgrom, Sarah A.; Gunther, Jillian R.; Fuller, C. David; Smith, Grace L.; Abou Yehia, Zeinab; Qiao, Wei; Wogan, Christine F.; Akhtari, Mani; Mawlawi, Osama; Medeiros, L. Jeffrey; Chuang, Hubert H.; Martin-Doyle, William; Armand, Philippe; LaCasce, Ann S.; Oki, Yasuhiro; Fanale, Michelle; Westin, Jason; Neelapu, Sattva; Nastoupil, Loretta

2018-01-01

Dose-adjusted rituximab plus etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH) has produced good outcomes in primary mediastinal B-cell lymphoma (PMBCL), but predictors of resistance to this treatment are unclear. We investigated whether [18F]fluorodeoxyglucose positron emission tomography–computed tomography (PET-CT) findings could identify patients with PMBCL who would not respond completely to DA-R-EPOCH. We performed a retrospective analysis of 65 patients with newly diagnosed stage I to IV PMBCL treated at 2 tertiary cancer centers who had PET-CT scans available before and after frontline therapy with DA-R-EPOCH. Pretreatment variables assessed included metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Optimal cutoff points for progression-free survival (PFS) were determined by a machine learning approach. Univariate and multivariable models were constructed to assess associations between radiographic variables and PFS. At a median follow-up of 36.6 months (95% confidence interval, 28.1-45.1), 2-year PFS and overall survival rates for the 65 patients were 81.4% and 98.4%, respectively. Machine learning–derived thresholds for baseline MTV and TLG were associated with inferior PFS (elevated MTV: hazard ratio [HR], 11.5; P = .019; elevated TLG: HR, 8.99; P = .005); other pretreatment clinical factors, including International Prognostic Index and bulky (>10 cm) disease, were not. On multivariable analysis, only TLG retained statistical significance (P = .049). Univariate analysis of posttreatment variables revealed that residual CT tumor volume, maximum standardized uptake value, and Deauville score were associated with PFS; a Deauville score of 5 remained significant on multivariable analysis (P = .006). A model combining baseline TLG and end-of-therapy Deauville score identified patients at increased risk of progression. PMID:29895624

[Neutrophil to lymphocyte ratio in peripheral blood: a novel independent prognostic factor in patients with head and neck squamous cell carcinoma].

PubMed

Wu, F; Wu, L L; Zhu, L X

2017-01-23

Objective: To investigate whether neutrophil to lymphocyte ratio (NLR) in peripheral blood can be an independent prognostic factor in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Clinical data of 97 HNSCC patients who received surgical treatment in our department between January 2008 and January 2012 were analyzed retrospectively. The 97 patients were divided into low NLR group (NLR≤5, n =69) and high NLR group (NLR>5, n =28) according to the NLR in preoperative peripheral blood. The relationships of NLR and clinicopathological features were analyzed. Kaplan-Meier method was used for univariate survival analysis and Cox proportional hazard model for multivariate survival analysis. Results: The clinical stages were significantly different between high NLR group and low NLR group ( P <0.05), however, the age, gender, location, lymph node metastasis, smoking and alcohol of the two groups showed no significant differences ( P > 0.05 of all). Univariate survival analysis showed that smoking, lymph node metastasis, clinical stage and NLR value were risk factors for 3-year overall survival (OS) rate and relapse-free survival (RFS) rate of HNSCC patients ( P <0.05). The OS rate of high NLR and low NLR groups was 42.9% and 91.3%, and the RFS rate was 44.2% and 80.1%, respectively, with a statistically significant difference ( P <0.05 for both). Cox multivariate survival analysis showed that clinical stage and NLR were independent factors for prognostic evaluation of HNSCC patients ( P <0.05 for both). Conclusions: NLR level is significantly associated with clinical stage of HNSCC. High NLR is an independent prognostic rick factor and plays an important role in prognostic evaluation of HNSCC patients.

Influence of microclimatic ammonia levels on productive performance of different broilers' breeds estimated with univariate and multivariate approaches.

PubMed

Soliman, Essam S; Moawed, Sherif A; Hassan, Rania A

2017-08-01

Birds litter contains unutilized nitrogen in the form of uric acid that is converted into ammonia; a fact that does not only affect poultry performance but also has a negative effect on people's health around the farm and contributes in the environmental degradation. The influence of microclimatic ammonia emissions on Ross and Hubbard broilers reared in different housing systems at two consecutive seasons (fall and winter) was evaluated using a discriminant function analysis to differentiate between Ross and Hubbard breeds. A total number of 400 air samples were collected and analyzed for ammonia levels during the experimental period. Data were analyzed using univariate and multivariate statistical methods. Ammonia levels were significantly higher (p< 0.01) in the Ross compared to the Hubbard breed farm, although no significant differences (p>0.05) were found between the two farms in body weight, body weight gain, feed intake, feed conversion ratio, and performance index (PI) of broilers. Body weight; weight gain and PI had increased values (p< 0.01) during fall compared to winter irrespective of broiler breed. Ammonia emissions were positively (although weekly) correlated with the ambient relative humidity (r=0.383; p< 0.01), but not with the ambient temperature (r=-0.045; p>0.05). Test of significance of discriminant function analysis did not show a classification based on the studied traits suggesting that they cannot been used as predictor variables. The percentage of correct classification was 52% and it was improved after deletion of highly correlated traits to 57%. The study revealed that broiler's growth was negatively affected by increased microclimatic ammonia concentrations and recommended the analysis of broilers' growth performance parameters data using multivariate discriminant function analysis.

Influence of microclimatic ammonia levels on productive performance of different broilers’ breeds estimated with univariate and multivariate approaches

PubMed Central

Soliman, Essam S.; Moawed, Sherif A.; Hassan, Rania A.

2017-01-01

Background and Aim: Birds litter contains unutilized nitrogen in the form of uric acid that is converted into ammonia; a fact that does not only affect poultry performance but also has a negative effect on people’s health around the farm and contributes in the environmental degradation. The influence of microclimatic ammonia emissions on Ross and Hubbard broilers reared in different housing systems at two consecutive seasons (fall and winter) was evaluated using a discriminant function analysis to differentiate between Ross and Hubbard breeds. Materials and Methods: A total number of 400 air samples were collected and analyzed for ammonia levels during the experimental period. Data were analyzed using univariate and multivariate statistical methods. Results: Ammonia levels were significantly higher (p< 0.01) in the Ross compared to the Hubbard breed farm, although no significant differences (p>0.05) were found between the two farms in body weight, body weight gain, feed intake, feed conversion ratio, and performance index (PI) of broilers. Body weight; weight gain and PI had increased values (p< 0.01) during fall compared to winter irrespective of broiler breed. Ammonia emissions were positively (although weekly) correlated with the ambient relative humidity (r=0.383; p< 0.01), but not with the ambient temperature (r=−0.045; p>0.05). Test of significance of discriminant function analysis did not show a classification based on the studied traits suggesting that they cannot been used as predictor variables. The percentage of correct classification was 52% and it was improved after deletion of highly correlated traits to 57%. Conclusion: The study revealed that broiler’s growth was negatively affected by increased microclimatic ammonia concentrations and recommended the analysis of broilers’ growth performance parameters data using multivariate discriminant function analysis. PMID:28919677

Prevalence of cigarette smoking and associated factors among secondary school teachers in Malaysia.

PubMed

Al-Naggar, Redhwan A; Jawad, Ammar A; Bobryshev, Yuri V

2012-01-01

The smoking prevalence in Malaysia is high, especially among men and adolescents. This study aimed to determine the prevalence and associated factors towards cigarette smoking among school teachers in Malaysia. This study was a school-based cross-sectional study conducted among 495 secondary school teachers. The questionnaire used in this study consisted of 29 questions categorized into two sections: socio-demographic characteristics and smoking behaviour. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) program 13.0. ANOVA; t-tests were used in univariate analysis; multiple linear regression was applied for multivariate analysis. The majority of the participants were female (81.6%), in the age group ranged between 30-39 years (44%), Malay (90.1%), married (89.7%), degree holders (85.1%), with monthly income ranged between 3000-3999 Ringgit Malaysia (33.5%), from urban areas (94.7%), their specialty is social studies (33.9%) and with no family history of cancer (83.6%). The prevalence of smoking among school teachers in Malaysia was found to be 7.8%. Regarding reasons to start smoking among school teachers: the major reason was found to be relaxation (33.3%), followed by stress-relief (28.2%). Univariate analysis showed that sex, educational status, monthly income and residency were significantly associated with smoking among school teachers (p<0.001, p=0.004, p=0.031, p=0.010; respectively). Multivariate analysis showed that gender and marital status were significantly associated with smoking among school teachers (p<0.001, p=0.033; respectively). The prevalence of smoking among school teachers in Malaysia was found to be relatively low. Sex, marital status, educational status, monthly income and residency were significantly associated with smoking among school teachers.

Positron emission tomography-computed tomography predictors of progression after DA-R-EPOCH for PMBCL.

PubMed

Pinnix, Chelsea C; Ng, Andrea K; Dabaja, Bouthaina S; Milgrom, Sarah A; Gunther, Jillian R; Fuller, C David; Smith, Grace L; Abou Yehia, Zeinab; Qiao, Wei; Wogan, Christine F; Akhtari, Mani; Mawlawi, Osama; Medeiros, L Jeffrey; Chuang, Hubert H; Martin-Doyle, William; Armand, Philippe; LaCasce, Ann S; Oki, Yasuhiro; Fanale, Michelle; Westin, Jason; Neelapu, Sattva; Nastoupil, Loretta

2018-06-12

Dose-adjusted rituximab plus etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH) has produced good outcomes in primary mediastinal B-cell lymphoma (PMBCL), but predictors of resistance to this treatment are unclear. We investigated whether [ 18 F]fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) findings could identify patients with PMBCL who would not respond completely to DA-R-EPOCH. We performed a retrospective analysis of 65 patients with newly diagnosed stage I to IV PMBCL treated at 2 tertiary cancer centers who had PET-CT scans available before and after frontline therapy with DA-R-EPOCH. Pretreatment variables assessed included metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Optimal cutoff points for progression-free survival (PFS) were determined by a machine learning approach. Univariate and multivariable models were constructed to assess associations between radiographic variables and PFS. At a median follow-up of 36.6 months (95% confidence interval, 28.1-45.1), 2-year PFS and overall survival rates for the 65 patients were 81.4% and 98.4%, respectively. Machine learning-derived thresholds for baseline MTV and TLG were associated with inferior PFS (elevated MTV: hazard ratio [HR], 11.5; P = .019; elevated TLG: HR, 8.99; P = .005); other pretreatment clinical factors, including International Prognostic Index and bulky (>10 cm) disease, were not. On multivariable analysis, only TLG retained statistical significance ( P = .049). Univariate analysis of posttreatment variables revealed that residual CT tumor volume, maximum standardized uptake value, and Deauville score were associated with PFS; a Deauville score of 5 remained significant on multivariable analysis ( P = .006). A model combining baseline TLG and end-of-therapy Deauville score identified patients at increased risk of progression. © 2018 by The American Society of Hematology.

Prediction of the space adaptation syndrome

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Homick, J. L.; Ryan, P.; Moseley, E. C.

1984-01-01

The univariate and multivariate relationships of provocative measures used to produce motion sickness symptoms were described. Normative subjects were used to develop and cross-validate sets of linear equations that optimally predict motion sickness in parabolic flights. The possibility of reducing the number of measurements required for prediction was assessed. After describing the variables verbally and statistically for 159 subjects, a factor analysis of 27 variables was completed to improve understanding of the relationships between variables and to reduce the number of measures for prediction purposes. The results of this analysis show that none of variables are significantly related to the responses to parabolic flights. A set of variables was selected to predict responses to KC-135 flights. A series of discriminant analyses were completed. Results indicate that low, moderate, or severe susceptibility could be correctly predicted 64 percent and 53 percent of the time on original and cross-validation samples, respectively. Both the factor analysis and the discriminant analysis provided no basis for reducing the number of tests.

Comparative study of contrast-enhanced ultrasound qualitative and quantitative analysis for identifying benign and malignant breast tumor lumps.

PubMed

Liu, Jian; Gao, Yun-Hua; Li, Ding-Dong; Gao, Yan-Chun; Hou, Ling-Mi; Xie, Ting

2014-01-01

To compare the value of contrast-enhanced ultrasound (CEUS) qualitative and quantitative analysis in the identification of breast tumor lumps. Qualitative and quantitative indicators of CEUS for 73 cases of breast tumor lumps were retrospectively analyzed by univariate and multivariate approaches. Logistic regression was applied and ROC curves were drawn for evaluation and comparison. The CEUS qualitative indicator-generated regression equation contained three indicators, namely enhanced homogeneity, diameter line expansion and peak intensity grading, which demonstrated prediction accuracy for benign and malignant breast tumor lumps of 91.8%; the quantitative indicator-generated regression equation only contained one indicator, namely the relative peak intensity, and its prediction accuracy was 61.5%. The corresponding areas under the ROC curve for qualitative and quantitative analyses were 91.3% and 75.7%, respectively, which exhibited a statistically significant difference by the Z test (P<0.05). The ability of CEUS qualitative analysis to identify breast tumor lumps is better than with quantitative analysis.

[Study on the factors impacting on early cochlear implantation between the eastern and western region of China].

PubMed

Xiao, Hanqiong; Li, Wei; Ma, Ruixia; Gong, Zhengpeng; Shi, Haibo; Li, Huawei; Chen, Bing; Jiang, Ye; Dai, Chunfu

2015-06-01

To describe tne regional different factors which impact on early cochlear implantation in prelingual deaf children between eastern and western regions of China. The charts of 113 children who received the cochlear implantation after 24 months old were reviewed and analyzed. Forty-five of them came from the eastern region (Jiangsu, Zhejiang or Shanghai) while 68 of them came from the western region (Ningxia or Guizhou). Parental interviews were conducted to collect information regarding the factors that impact on early cochlear implantation. Result:Based on the univariate logistic regression analysis, the odds ratio (OR) value of universal newborn hearing screening (UNHS) was 5. 481, which indicated the correlation of UNHS with early cochlear implantation is significant. There was statistical difference between the 2 groups (P<0. 01). For the financial burden, the OR value was 3. 521(strong correlation) and there was statistical difference between the 2 groups (P<0. 01). For the communication barriers and community location, the OR value was 0. 566 and 1. 128 respectively, and there was no statistical difference between the 2 groups (P>0. 05). The multivariate analysis indicated that the UNHS and financial burden are statistically different between the eastern and western regions (P=0. 00 and 0. 040 respectively). The UNHS and financial burden are statistically different between the eastern reinforced in the western region. In addition, the government and society should provide powerful policy and more financial support in the western region of China. The innovation of management system is also helpful to the early cochlear implantation.

The status of diabetes control in Kurdistan province, west of Iran.

PubMed

Esmailnasab, Nader; Afkhamzadeh, Abdorrahim; Roshani, Daem; Moradi, Ghobad

2013-09-17

Based on some estimation more than two million peoples in Iran are affected by Type 2 diabetes. The present study was designed to evaluate the status of diabetes control among Type 2 diabetes patients in Kurdistan, west of Iran and its associated factors. In our cross sectional study conducted in 2010, 411 Type 2 diabetes patients were randomly recruited from Sanandaj, Capital of Kurdistan. Chi square test was used in univariate analysis to address the association between HgAlc and FBS status and other variables. The significant results from Univariate analysis were entered in multivariate analysis and multinomial logistic regression model. In 38% of patients, FBS was in normal range (70-130) and in 47% HgA1c was <7% which is normal range for HgA1c. In univariate analysis, FBS level was associated with educational levels (P=0.001), referral style (P=0.001), referral time (P=0.009), and insulin injection (P=0.016). In addition, HgA1c had a relationship with sex (P=0.023), age (P=0.035), education (P=0.001), referral style (P=0.001), and insulin injection (P=0.008). After using multinomial logistic regression for significant results of univariate analysis, it was found that FBS was significantly associated with referral style. In addition HgA1c was significantly associated with referral style and Insulin injection. Although some of patients were under the coverage of specialized cares, but their diabetes were not properly controlled.

A Comparison of Latent Growth Models for Constructs Measured by Multiple Items

ERIC Educational Resources Information Center

Leite, Walter L.

2007-01-01

Univariate latent growth modeling (LGM) of composites of multiple items (e.g., item means or sums) has been frequently used to analyze the growth of latent constructs. This study evaluated whether LGM of composites yields unbiased parameter estimates, standard errors, chi-square statistics, and adequate fit indexes. Furthermore, LGM was compared…

Survey of Working Conditions. Final Report on Univariate and Bivariate Tables.

ERIC Educational Resources Information Center

Michigan Univ., Ann Arbor. Survey Research Center.

A nationwide survey of employed persons was conducted to provide information on labor standards problems, assess the impact of working conditions on workers, develop job satisfaction measures, and establish statistics for similar data collections. The survey revealed that the majority of workers expressed satisfaction with their jobs but they also…

Down regulation of E-Cadherin (ECAD) - a predictor for occult metastatic disease in sentinel node biopsy of early squamous cell carcinomas of the oral cavity and oropharynx.

PubMed

Huber, Gerhard F; Züllig, Lena; Soltermann, Alex; Roessle, Matthias; Graf, Nicole; Haerle, Stephan K; Studer, Gabriela; Jochum, Wolfram; Moch, Holger; Stoeckli, Sandro J

2011-06-03

Prognostic factors in predicting occult lymph node metastasis in patients with head and neck squamous-cell carcinoma (HNSCC) are necessary to improve the results of the sentinel lymph node procedure in this tumour type. The E-Cadherin glycoprotein is an intercellular adhesion molecule in epithelial cells, which plays an important role in establishing and maintaining intercellular connections. To determine the value of the molecular marker E-Cadherin in predicting regional metastatic disease. E-Cadherin expression in tumour tissue of 120 patients with HNSCC of the oral cavity and oropharynx were evaluated using the tissue microarray technique. 110 tumours were located in the oral cavity (91.7%; mostly tongue), 10 tumours in the oropharynx (8.3%). Intensity of E-Cadherin expression was quantified by the Intensity Reactivity Score (IRS). These results were correlated with the lymph node status of biopsied sentinel lymph nodes. Univariate and multivariate analysis was used to determine statistical significance. pT-stage, gender, tumour side and location did not correlate with lymph node metastasis. Differentiation grade (p = 0.018) and down regulation of E-Cadherin expression significantly correlate with positive lymph node status (p = 0.005) in univariate and multivariate analysis. These data suggest that loss of E-cadherin expression is associated with increased lymhogeneous metastasis of HNSCC. E-cadherin immunohistochemistry may be used as a predictor for lymph node metastasis in squamous cell carcinoma of the oral cavity and oropharynx. 2b.

Computed tomography predictors of hepatocellular carcinoma tumour necrosis after chemoembolization

PubMed Central

Bryant, Mary K; Dorn, David P; Zarzour, Jessica; Smith, J Kevin; Redden, David T; Saddekni, Souheil; Aal, Ahmed Kamel Abdel; Gray, Stephen H; Eckhoff, Devin E; DuBay, Derek A

2014-01-01

Background Radiographical features associated with a favourable response to trans-arterial chemoembolization (TACE) are poorly defined for patients with hepatocellular carcinoma (HCC). Methods From 2008 to 2012, all first TACE interventions for HCC performed at the University of Alabama at Birmingham (UAB) were retrospectively reviewed. Only patients with a pre-TACE and a post-TACE computed tomography (CT) scan were included in the analyses (n = 115). HCC tumour response to TACE was quantified via the the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. Univariate and multivariable analyses were constructed. Results The index HCC tumours experienced a > 90% or complete tumour necrosis in 59/115 (51%) of patients after the first TACE intervention. On univariate analysis, smaller tumour size, peripheral tumour location and arterial enhancement were associated with a > 90% or complete tumour necrosis, whereas, only smaller tumour size [odds ratio (OR) 0.62; 95% confidence interval (CI) 0.48, 0.81] and peripheral location (OR 6.91; 95% CI 1.75, 27.29) were significant on multivariable analysis. There was a trend towards improved survival in the patients that experienced a > 90% or complete tumour necrosis (P = 0.08). Conclusions Peripherally located smaller HCC tumours are most likely to experience a > 90% or complete tumour necrosis after TACE. Surprisingly, arterial-phase enhancement and portal venous-phase washout were not significantly predictive of TACE-induced tumour necrosis. The TACE response was not statistically associated with improved survival. PMID:23980917

True survival benefit of lung transplantation for cystic fibrosis patients: the Zurich experience.

PubMed

Hofer, Markus; Benden, Christian; Inci, Ilhan; Schmid, Christoph; Irani, Sarosh; Speich, Rudolf; Weder, Walter; Boehler, Annette

2009-04-01

Lung transplantation is the ultimate therapy for end-stage cystic fibrosis (CF) lung disease; however, the debate continues as to whether lung transplantation improves survival. We report post-transplant outcome in CF at our institution by comparing 5-year post-transplant survival with a calculated 5-year survival without lung transplantation, using a predictive 5-year survivorship model, and describe pre-transplant parameters influencing transplant outcome. CF patients undergoing lung transplantation at our center were included (1992 to 2007). Survival rates were calculated and compared, and univariate and multivariate Cox regression analyses were used for statistical assessment. Eighty transplants were performed in CF patients, 11 (13.8%) of whom were children. Mean age at transplant was 26.2 years (95% confidence interval: 24.4 to 28.0). The Liou raw score at transplant was -20 (95% confidence interval: -16 to -24), resulting in an estimated 5-year survival without transplantation of 33 +/- 14%, compared with a 5-year post-transplant survival of 68.2 +/- 5.6%. Further improvement was noted in the recent transplant era (since 2000), with a 5-year survival of 72.7 +/- 7.3%. Univariate analysis revealed that later year of transplant and diagnosis of diabetes influenced survival positively. Pediatric age had no negative impact. In the multivariate analysis, only diabetes influenced survival, in a positive manner. Lung transplantation performed at centers having experience with the procedure can offer a true survival benefit to patients with end-stage CF lung disease.

Percentage of positive prostate biopsies independently predicts biochemical outcome following radiation therapy for prostate cancer.

PubMed

Gabriele, Domenico; Garibaldi, Monica; Girelli, Giuseppe; Taraglio, Stefano; Duregon, Eleonora; Gabriele, Pietro; Guiot, Caterina; Bollito, Enrico

2016-06-01

This work aims to definitely show the ability of percentage of positive biopsy cores (%PC) to independently predict biochemical outcome beyond traditional pretreatment risk-factors in prostate cancer (PCa) patients treated with radiotherapy. A cohort of 2493 men belonging to the EUREKA-2 retrospective multicentric database on (PCa) and treated with external-beam radiation therapy (EBRT) as primary treatment comprised the study population (median follow-up 50 months). A Cox regression time to prostate-specific antigen (PSA) failure analysis was performed to evaluate the predictive power of %PC, both in univariate and multivariate settings, with age, pretreatment PSA, clinical-radiological staging, bioptic Gleason Score (bGS), RT dose and RT +/- ADT as covariates. P statistics for %PC is lower than 0.001 both in univariate and multivariate models. %PC as a continuous variable yields an AUC of 69% in ROC curve analysis for biochemical relapse. Four classes of %PC (1-20%, 21-50%, 51-80% and 81-100%) distinctly split patients for risk of biochemical relapse (overall log-rank test P<0.0001), with biochemical progression free survival (bPFS) at 5-years ranging from 88% to 58% and 10-years bPFS ranging from 80% to 38%. We strongly affirm the usefulness of %PC information beyond main risk factors (PSA, staging and bGS) in predicting biochemical recurrence after EBRT for PCa. The stratification of patients according to %PC may be valuable to further discriminate cases with favourable or adverse prognosis.

A Cross-Sectional Study of the Association between Autoantibodies and Qualitative Ultrasound Index of Bone in an Elderly Sample without Clinical Autoimmune Disease

PubMed Central

McEvoy, Mark; Kelly, Brian; Agnew, Linda; Walker, Frederick R.; Boyle, Michael

2018-01-01

Bone loss is characteristic of the ageing process and a common complication of many autoimmune diseases. Research has highlighted a potential role of autoantibodies in pathologic bone loss. The confounding effects of immunomodulatory drugs make it difficult to establish the contribution of autoantibodies amongst autoimmune disease sufferers. We attempted to examine the relationship between autoantibodies and bone mass in a population of 2812 elderly participants without clinical autoimmune disease. Serum samples were assayed for a panel of autoantibodies (anti-nuclear, extractable nuclear antigen, anti-neutrophil cytoplasmic, thyroid peroxidase, tissue transglutaminase, anti-cardiolipin, rheumatoid factor, and cyclic citrullinated peptide). Bone mass was measured using quantitative ultrasound (QUS) of the calcaneus. The relationship between each autoantibody and bone mass was determined using linear regression models. Anti-nuclear autoantibodies were the most prevalent, positive in approximately 11%, and borderline in roughly 23% of our sample. They were also the only autoantibody observed to be significantly associated with QUS index in the univariate analysis (n = 1628; r = −0.20; 95% CI: −0.40–0.00; p = 0.046). However, statistical significance was lost after adjustment for various other potential confounders. None of the other autoantibodies was associated with QUS index in either univariate or multivariate analysis. We are limited by the cross-sectional nature of the study and the low prevalence of autoantibodies in our nonclinical sample. PMID:29854851

Does uneven geographic distribution of urologists effect bladder and prostate cancers mortality? National health insurance data in Korea from 2007-2011.

PubMed

Kim, Jae Heon; Sun, Hwa Yeon; Kim, Hyun Jung; Ko, Young Myoung; Chun, Dong-Il; Park, Jae Young

2017-09-12

The relationship between distribution of urologists and mortality of bladder and prostate cancers has not been clearly established. The aim of this study was to investigate the relationship between uneven distribution of urologists and urologic cancer specific mortality at country level. Data from the National Health Insurance Service and National Statistical Office in Korea from 2007 to 2011 were analyzed in this ecological study. Univariate and multivariable regression analyses were performed to determine risk factors for age standardized mortality rates (ASMR) of bladder and prostate cancers. Linear regression analysis showed a markedly ( p < 0.001) uneven distribution of urologists between metropolitan and non-metropolitan areas. There was no significant difference in cancer specific ASMRs for either bladder cancer or prostate cancer. Univariate analysis after adjusting for time showed that country area, urologist density, and income were significant factors affecting bladder cancer incidence ( p < 0.001, p = 0.013, and p < 0.001, respectively). It also showed that the number of training hospitals was a significant factor for prostate cancer incidence ( p = 0.002). Although country area showed borderline significance ( p = 0.056) for ASMR of bladder cancer, urologist density was not related to ASMR of bladder cancer or prostate cancer. Although there was a marked difference in urologist density between metropolitan and non-metropolitan areas for these years analyzed, mortality rates of bladder and prostate cancers were not significantly affected by country area or urologist density.

Does uneven geographic distribution of urologists effect bladder and prostate cancers mortality? National health insurance data in Korea from 2007–2011

PubMed Central

Kim, Jae Heon; Sun, Hwa Yeon; Kim, Hyun Jung; Ko, Young Myoung; Chun, Dong-Il; Park, Jae Young

2017-01-01

The relationship between distribution of urologists and mortality of bladder and prostate cancers has not been clearly established. The aim of this study was to investigate the relationship between uneven distribution of urologists and urologic cancer specific mortality at country level. Data from the National Health Insurance Service and National Statistical Office in Korea from 2007 to 2011 were analyzed in this ecological study. Univariate and multivariable regression analyses were performed to determine risk factors for age standardized mortality rates (ASMR) of bladder and prostate cancers. Linear regression analysis showed a markedly (p < 0.001) uneven distribution of urologists between metropolitan and non-metropolitan areas. There was no significant difference in cancer specific ASMRs for either bladder cancer or prostate cancer. Univariate analysis after adjusting for time showed that country area, urologist density, and income were significant factors affecting bladder cancer incidence (p < 0.001, p = 0.013, and p < 0.001, respectively). It also showed that the number of training hospitals was a significant factor for prostate cancer incidence (p = 0.002). Although country area showed borderline significance (p = 0.056) for ASMR of bladder cancer, urologist density was not related to ASMR of bladder cancer or prostate cancer. Although there was a marked difference in urologist density between metropolitan and non-metropolitan areas for these years analyzed, mortality rates of bladder and prostate cancers were not significantly affected by country area or urologist density. PMID:29029431

Association between single nucleotide polymorphisms of the transforming growth factor β1 gene and the risk of severe radiation esophagitis in patients with lung cancer.

PubMed

Guerra, Jose Luis Lopez; Gomez, Daniel; Wei, Qingyi; Liu, Zhengshen; Wang, Li-E; Yuan, Xianglin; Zhuang, Yan; Komaki, Ritusko; Liao, Zhongxing

2012-12-01

We investigated the association between single nucleotide polymorphisms (SNPs) in the transforming growth factor β1 (TGFβ1) gene and the risk of radiation-induced esophageal toxicity (RE) in patients with non-small-cell lung cancer (NSCLC). Ninety-seven NSCLC patients with available genomic DNA samples and mostly treated with intensity modulated radio(chemo)therapy from 2003 to 2006 were used as a test dataset and 101 NSCLC patients treated with 3-dimensional conformal radio(chemo)therapy from 1998 to 2002 were used as a validation set. We genotyped three SNPs of the TGFβ1 gene (rs1800469:C-509T, rs1800471:G915C, and rs1982073:T869C) by the polymerase chain reaction restriction fragment length polymorphism method. In the test dataset, the CT/TT genotypes of TGFβ1 rs1800469:C-509T were associated with a statistically significant higher risk of RE grade⩾3 in univariate (P=0.026) and multivariate analysis (P=0.045) when compared with the CC genotype. These results were again observed in both univariate (P=0.045) and multivariate (P=0.023) analysis in the validation dataset. We found and validated that the TGFβ1 rs1800469:C-509T genotype is associated with severe RE. This response marker may be used for guiding therapy intensity in an individual patient, which would further the goal of individualized therapy. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Experiments with a three-dimensional statistical objective analysis scheme using FGGE data

NASA Technical Reports Server (NTRS)

Baker, Wayman E.; Bloom, Stephen C.; Woollen, John S.; Nestler, Mark S.; Brin, Eugenia

1987-01-01

A three-dimensional (3D), multivariate, statistical objective analysis scheme (referred to as optimum interpolation or OI) has been developed for use in numerical weather prediction studies with the FGGE data. Some novel aspects of the present scheme include: (1) a multivariate surface analysis over the oceans, which employs an Ekman balance instead of the usual geostrophic relationship, to model the pressure-wind error cross correlations, and (2) the capability to use an error correlation function which is geographically dependent. A series of 4-day data assimilation experiments are conducted to examine the importance of some of the key features of the OI in terms of their effects on forecast skill, as well as to compare the forecast skill using the OI with that utilizing a successive correction method (SCM) of analysis developed earlier. For the three cases examined, the forecast skill is found to be rather insensitive to varying the error correlation function geographically. However, significant differences are noted between forecasts from a two-dimensional (2D) version of the OI and those from the 3D OI, with the 3D OI forecasts exhibiting better forecast skill. The 3D OI forecasts are also more accurate than those from the SCM initial conditions. The 3D OI with the multivariate oceanic surface analysis was found to produce forecasts which were slightly more accurate, on the average, than a univariate version.

[Assessment of self-esteem in pregnant women using Rosenberg's Self-Esteem Scale].

PubMed

Maçola, Ligia; do Vale, Ianê Nogueira; Carmona, Elenice Valentim

2010-09-01

The objective of this descriptive, cross-sectional study was to evaluate the self-esteem of 127 pregnant women seen in a prenatal care program conducted in a public school hospital. Data collection was performed using the Rosenberg's Self-esteem Scale; unsatisfactory self-esteem was related to socio-demographic and health variables of the pregnant woman, and to the presence or absence of support systems. Descriptive and univariate statistical analysis were used to assess possible associations. Pregnant women who had low scores for self-esteem were 60% of all subjects. As for the sociodemographic data, women with fewer years of education presented higher frequency of lower self-esteem scores, which disagrees with other studies. Pregnant women who report having an unplanned pregnancy presented higher prevalence of low self-esteem than those who reported having planned their pregnancy. The lack of support from the partner to look after the baby was also associated to the pregnant women's low self-esteem. Other associations between variables were not statistically significant.

Pulp calcification in traumatized primary teeth: prevalence and associated factors.

PubMed

Mello-Moura, A C V; Bonini, G A V C; Zardetto, C G D C; Rodrigues, C R M D; Wanderley, M T

2011-01-01

To establish the prevalence of pulp calcifications in 946 patients at the Research and Clinical Center of Dental Trauma in Primary Teeth. The clinical and radiographic records of l675 traumatized primary teeth were evaluated. Statistical analysis was performed using chi-square and univariate logistic regression. 197 (20.8%) patients showed pulp calcification (PC). A total of 250 (14.9%) calcified teeth were observed In most teeth, PC appeared within the first 12 months following trauma. PC prevalence was higher in cases of repeated trauma (29.6%) than in single trauma (16.4%), p < 0.05, with a 2.14 chance of showing pulp calcification when a child suffered recurrent trauma. Most teeth showing calcified pulp, suffered trauma to the supportive tissue (67.4%), being statistically significant in relation to the trauma to dental tissue (p < 0.05). PC is a sequelae in cases of trauma to the primary dentition; teeth that suffered recurrent traumatic injuries show higher risk of presenting.

Analysis of vector wind change with respect to time for Cape Kennedy, Florida: Wind aloft profile change vs. time, phase 1

NASA Technical Reports Server (NTRS)

Adelfang, S. I.

1977-01-01

Wind vector change with respect to time at Cape Kennedy, Florida, is examined according to the theory of multivariate normality. The joint distribution of the four variables represented by the components of the wind vector at an initial time and after a specified elapsed time is hypothesized to be quadravariate normal; the fourteen statistics of this distribution, calculated from fifteen years of twice daily Rawinsonde data are presented by monthly reference periods for each month from 0 to 27 km. The hypotheses that the wind component changes with respect to time is univariate normal, the joint distribution of wind component changes is bivariate normal, and the modulus of vector wind change is Rayleigh, has been tested by comparison with observed distributions. Statistics of the conditional bivariate normal distributions of vector wind at a future time given the vector wind at an initial time are derived. Wind changes over time periods from one to five hours, calculated from Jimsphere data, are presented.

The fragility of statistically significant findings from randomized trials in head and neck surgery.

PubMed

Noel, Christopher W; McMullen, Caitlin; Yao, Christopher; Monteiro, Eric; Goldstein, David P; Eskander, Antoine; de Almeida, John R

2018-04-23

The Fragility Index (FI) is a novel tool for evaluating the robustness of statistically significant findings in a randomized control trial (RCT). It measures the number of events upon which statistical significance depends. We sought to calculate the FI scores for RCTs in the head and neck cancer literature where surgery was a primary intervention. Potential articles were identified in PubMed (MEDLINE), Embase, and Cochrane without publication date restrictions. Two reviewers independently screened eligible RCTs reporting at least one dichotomous and statistically significant outcome. The data from each trial were extracted and the FI scores were calculated. Associations between trial characteristics and FI were determined. In total, 27 articles were identified. The median sample size was 67.5 (interquartile range [IQR] = 42-143) and the median number of events per trial was 8 (IQR = 2.25-18.25). The median FI score was 1 (IQR = 0-2.5), meaning that changing one patient from a nonevent to an event in the treatment arm would change the result to a statistically nonsignificant result, or P > .05. The FI score was less than the number of patients lost to follow-up in 71% of cases. The FI score was found to be moderately correlated with P value (ρ = -0.52, P = .007) and with journal impact factor (ρ = 0.49, P = .009) on univariable analysis. On multivariable analysis, only the P value was found to be a predictor of FI score (P = .001). Randomized trials in the head and neck cancer literature where surgery is a primary modality are relatively nonrobust statistically with low FI scores. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

Predictors of poor outcome despite recanalization: a multiple regression analysis of the NASA registry.

PubMed

Linfante, Italo; Starosciak, Amy K; Walker, Gail R; Dabus, Guilherme; Castonguay, Alicia C; Gupta, Rishi; Sun, Chung-Huan J; Martin, Coleman; Holloway, William E; Mueller-Kronast, Nils; English, Joey D; Malisch, Tim W; Marden, Franklin A; Bozorgchami, Hormozd; Xavier, Andrew; Rai, Ansaar T; Froehler, Michael T; Badruddin, Aamir; Nguyen, Thanh N; Taqi, M Asif; Abraham, Michael G; Janardhan, Vallabh; Shaltoni, Hashem; Novakovic, Roberta; Yoo, Albert J; Abou-Chebl, Alex; Chen, Peng R; Britz, Gavin W; Kaushal, Ritesh; Nanda, Ashish; Issa, Mohammad A; Nogueira, Raul G; Zaidat, Osama O

2016-03-01

Mechanical thrombectomy with stent-retrievers results in higher recanalization rates compared with previous devices. Despite successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b) of 70-83%, good outcomes by 90-day modified Rankin Scale (mRS) score ≤2 are achieved in only 40-55% of patients. We evaluated predictors of poor outcomes (mRS >2) despite successful recanalization (TICI ≥2b) in the North American Solitaire Stent Retriever Acute Stroke (NASA) registry. Logistic regression was used to evaluate baseline characteristics and recanalization outcomes for association with 90-day mRS score of 0-2 (good outcome) vs 3-6 (poor outcome). Univariate tests were carried out for all factors. A multivariable model was developed based on backwards selection from the factors with at least marginal significance (p≤0.10) on univariate analysis with the retention criterion set at p≤0.05. The model was refit to minimize the number of cases excluded because of missing covariate values; the c-statistic was a measure of predictive power. Of 354 patients, 256 (72.3%) were recanalized successfully. Based on 234 recanalized patients evaluated for 90-day mRS score, 116 (49.6%) had poor outcomes. Univariate analysis identified an increased risk of poor outcome for age ≥80 years, occlusion site of internal carotid artery (ICA)/basilar artery, National Institute of Health Stroke Scale (NIHSS) score ≥18, history of diabetes mellitus, TICI 2b, use of rescue therapy, not using a balloon-guided catheter or intravenous tissue plasminogen activator (IV t-PA), and >30 min to recanalization (p≤0.05). In multivariable analysis, age ≥80 years, occlusion site ICA/basilar, initial NIHSS score ≥18, diabetes, absence of IV t-PA, ≥3 passes, and use of rescue therapy were significant independent predictors of poor 90-day outcome in a model with good predictive power (c-index=0.80). Age, occlusion site, high NIHSS, diabetes, no IV t-PA, ≥3 passes, and use of rescue therapy are associated with poor 90-day outcome despite successful recanalization. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion.

PubMed

Balaratnasingam, Chandrakumar; Inoue, Maiko; Ahn, Seungjun; McCann, Jesse; Dhrami-Gavazi, Elona; Yannuzzi, Lawrence A; Freund, K Bailey

2016-11-01

To determine if the area of the foveal avascular zone (FAZ) is correlated with visual acuity (VA) in diabetic retinopathy (DR) and retinal vein occlusion (RVO). Cross-sectional study. Ninety-five eyes of 66 subjects with DR (65 eyes), branch retinal vein occlusion (19 eyes), and central retinal vein occlusion (11 eyes). Structural optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) and OCT angiography (OCTA; Avanti, Optovue RTVue XR) data from a single visit were analyzed. FAZ area, point thickness of central fovea, central 1-mm subfield thickness, the occurrence of intraretinal cysts, ellipsoid zone disruption, and disorganization of retinal inner layers (DRIL) length were measured. VA was also recorded. Correlations between FAZ area and VA were explored using regression models. Main outcome measure was VA. Mean age was 62.9±13.2 years. There was no difference in demographic and OCT-derived anatomic measurements between branch retinal vein occlusion and central retinal vein occlusion groups (all P ≥ 0.058); therefore, data from the 2 groups were pooled together to a single RVO group for further statistical comparisons. Univariate and multiple regression analysis showed that the area of the FAZ was significantly correlated with VA in DR and RVO (all P ≤ 0.003). The relationship between FAZ area and VA varied with age (P = 0.026) such that for a constant FAZ area, an increase in patient age was associated with poorer vision (rise in logarithm of the minimum angle of resolution visual acuity). Disruption of the ellipsoid zone was significantly correlated with VA in univariate and multiple regression analysis (both P < 0.001). Occurrence of intraretinal cysts, DRIL length, and lens status were significantly correlated with VA in the univariate regression analysis (P ≤ 0.018) but not the multiple regression analysis (P ≥ 0.210). Remaining variables evaluated in this study were not predictive of VA (all P ≥ 0.225). The area of the FAZ is significantly correlated with VA in DR and RVO and this relationship is modulated by patient age. Further study about FAZ area and VA correlations during the natural course of retinal vascular diseases and following treatment is warranted. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Use of erythropoietin is associated with threshold retinopathy of prematurity (ROP) in preterm ELBW neonates: a retrospective, cohort study from two large tertiary NICUs in Italy.

PubMed

Manzoni, Paolo; Memo, Luigi; Mostert, Michael; Gallo, Elena; Guardione, Roberta; Maestri, Andrea; Saia, Onofrio Sergio; Opramolla, Anna; Calabrese, Sara; Tavella, Elena; Luparia, Martina; Farina, Daniele

2014-09-01

Retinopathy of prematurity (ROP) is a multifactorial disease with evidence of many associated risk factors. Erythropoietin has been reported to be associated with this disorder in a murine model, as well as in humans in some single-center reports. We reviewed the data from two large tertiary NICUs in Italy to test the hypothesis that the use of erythropoietin may be associated with the development of the most severe stages of ROP in extremely low birth weight (ELBW) neonates. Retrospective study by review of patient charts and eye examination index cards on infants with birth weight <1000g admitted to two large tertiary NICUs in Northern Italy (Sant'Anna Hospital NICU in Torino, and Ca' Foncello Hospital Neonatology in Treviso) in the years 2005 to 2007. Standard protocol of administration of EPO in the two NICUs consisted of 250 UI/kg three times a week for 6-week courses (4-week in 1001-1500g infants). Univariate analysis was performed to assess whether the use of EPO was associated with severe (threshold) ROP. A control, multivariate statistical analysis was performed by entering into a logistic regression model a number of neonatal and perinatal variables that - in univariate analysis - had been associated with threshold ROP. During the study period, 211 ELBW infants were born at the two facilities and survived till discharge. Complete data were obtained for 197 of them. Threshold retinopathy of prematurity occurred in 26.9% (29 of 108) of ELBW infants who received erythropoietin therapy, as compared with 13.5% (12 of 89) of those who did not receive erythropoietin (OR 2.35; 95% CI 1.121-4.949; p=0.02 in univariate analysis, and p=0.04 at multivariate logistic regression after controlling for the following variables: birth weight, gestational age, days on supplemental oxygen, systemic fungal infection, vaginal delivery). Use of erythropoietin was not significantly associated with other major sequelae of prematurity (intraventricular hemorrhage, bronchopulmonary dysplasia, necrotizing enterocolitis). © 2014 Elsevier Ireland Ltd. All rights reserved. Use of erythropoietin is an additional, independent predictor of threshold ROP in ELBW neonates. Larger prospective, population-based studies should further clarify the extent of this association. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

determination of sex in south african blacks by discriminant function analysis of mandibular linear dimensions : A preliminary investigation using the zulu local population.

PubMed

Franklin, Daniel; O'Higgins, Paul; Oxnard, Charles E; Dadour, Ian

2006-12-01

The determination of sex is a critical component in forensic anthropological investigation. The literature attests to numerous metrical standards, each utilizing diffetent skeletal elements, for sex determination in South A frican Blacks. Metrical standards are popular because they provide a high degree of expected accuracy and are less error-prone than subjective nonmetric visual techniques. We note, however, that there appears to be no established metric mandible discriminant function standards for sex determination in this population.We report here on a preliminary investigation designed to evaluate whether the mandible is a practical element for sex determination in South African Blacks. The sample analyzed comprises 40 nonpathological Zulu individuals drawn from the R.A. Dart Collection. Ten linear measurements, obtained from mathematically trans-formed three-dimensional landmark data, are analyzed using basic univariate statistics and discriminant function analyses. Seven of the 10 measurements examined are found to be sexually dimorphic; the dimensions of the ramus are most dimorphic. The sex classification accuracy of the discriminant functions ranged from 72.5 to 87.5% for the univariate method, 92.5% for the stepwise method, and 57.5 to 95% for the direct method. We conclude that the mandible is an extremely useful element for sex determination in this population.

Gamma Knife radiosurgery for intracranial hemangioblastoma.

PubMed

Silva, Danilo; Grabowski, Mathew M; Juthani, Rupa; Sharma, Mayur; Angelov, Lilyana; Vogelbaum, Michael A; Chao, Samuel; Suh, John; Mohammadi, Alireza; Barnett, Gene H

2016-09-01

Gamma knife radiosurgery (GKRS) has become a treatment option for intracranial hemangioblastomas, especially in patients with poor clinical status and also high-risk surgical candidates. The objective of this study was to analyze clinical outcome and tumor control rates. Retrospective chart review revealed 12 patients with a total of 20 intracranial hemangioblastomas treated with GKRS from May 1998 until December 2014. Kaplan-Meier plots were used to calculate the actuarial local tumor control rates and rate of recurrence following GKRS. Univariate analysis, including log rank test and Wilcoxon test were used on the Kaplan-Meier plots to evaluate the predictors of tumor progression. Two-tailed p value of <0.05 was considered as significant. Median follow-up was 64months (2-184). Median tumor volume pre-GKRS was 946mm(3) (79-15970), while median tumor volume post-GKRS was 356mm(3) (30-5404). Complications were seen in two patients. Tumor control rates were 100% at 1year, 90% at 3years, and 85% at 5years, using the Kaplan-Meier method. There were no statistically significant univariate predictors of progression identified, although there was a trend towards successful tumor control in solid tumors (p=0.07). GKRS is an effective and safe option for treating intracranial hemangioblastoma with favorable tumor control rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Social Well-Being and Related Factors in Students of School of Nursing and Midwifery.

PubMed

Salehi, Alireza; Marzban, Maryam; Sourosh, Maryam; Sharif, Farkhondeh; Nejabat, Mahmoud; Imanieh, Mohammad Hadi

2017-01-01

According to the World Health Organization viewpoint, social well-being is an important dimension of health along with physical and mental aspects. Evaluation of social well-being is necessary in students, especially in medical sciences students due to future responsibility as health care professionals. The present study attempted to investigate the level of social well-being, five domains of it (like actualization, integration, contribution), and some related factors in the school of nursing and midwifery students. This cross-sectional study was carried out between Julys to December 2015 and comprised 346 students in the school of nursing and midwifery in Shiraz University of Medical Sciences, Shiraz, Iran. Social well-being, socio-demographic status and physical activity were measured by valid questionnaires. Univariate linear regression analysis, multiple imputation method, ANOVA and independent sample t-test were used as different statistical methods. The P values less than 0.05 were considered as statistically significant. The mean score of social well-being was 50. The minimum and maximum scores of social well-being were 20 to 100. Married students had higher social well-being than single students in univariate linear regression (Beta: 2.111, 95% CI: (0.387 to 3.738), P=0.017). Also, social integration had higher scores in married students (P=0.015). Social actualization was higher in male students (P=0.015); on the other hand, social contribution was higher in female students (P=0.026). The results of our study showed that social well-being status of students in this research was not satisfactory. Designing and conducting programs for promotion of social well-being, for example preparing facilities for marriage of students, can be helpful. Evaluation of social well-being in students of other schools with multicenter studies seems to be useful.

MR image features predicting hemorrhagic transformation in acute cerebral infarction: a multimodal study.

PubMed

Liu, Chunming; Dong, Zhengchao; Xu, Liang; Khursheed, Aiman; Dong, Longchun; Liu, Zhenxing; Yang, Jun; Liu, Jun

2015-11-01

The aims of this study were to observe magnetic resonance imaging (MRI) features and the frequency of hemorrhagic transformation (HT) in patients with acute cerebral infarction and to identify the risk factors of HT. We first performed multimodal MRI (anatomical, diffusion weighted, and susceptibility weighted) scans on 87 patients with acute cerebral infarction within 24 hours after symptom onset and documented the image findings. We then performed follow-up examinations 3 days to 2 weeks after the onset or whenever the conditions of the patients worsened within 3 days. We utilized univariate statistics to identify the correlations between HT and image features and used multivariate logistical regression to correct for confounding factors to determine relevant independent image features of HT. HT was observed in 17 out of total 87 patients (19.5 %). The infarct size (p = 0.021), cerebral microbleeds (CMBs) (p = 0.004), relative apparent diffusion (rADC) (p = 0.023), and venous anomalies (p = 0.000) were significantly related with HT in the univariate statistics. Multivariate analysis demonstrated that CMBs (odd ratio (OR) = 0.082; 95 % confidence interval (CI) = 0.011-0.597; p = 0.014), rADC (OR = 0.000; 95 % CI = 0.000-0.692; p = 0.041), and venous anomalies (OR = 0.066; 95 % CI = 0.011-0.403; p = 0.003) were independent risk factors for HT. The frequency of HT is 19.5 % in this study. CMBs, rADC, and venous anomalies are independent risk factors for HT of acute cerebral infarction.

Effect of correlation on covariate selection in linear and nonlinear mixed effect models.

PubMed

Bonate, Peter L

2017-01-01

The effect of correlation among covariates on covariate selection was examined with linear and nonlinear mixed effect models. Demographic covariates were extracted from the National Health and Nutrition Examination Survey III database. Concentration-time profiles were Monte Carlo simulated where only one covariate affected apparent oral clearance (CL/F). A series of univariate covariate population pharmacokinetic models was fit to the data and compared with the reduced model without covariate. The "best" covariate was identified using either the likelihood ratio test statistic or AIC. Weight and body surface area (calculated using Gehan and George equation, 1970) were highly correlated (r = 0.98). Body surface area was often selected as a better covariate than weight, sometimes as high as 1 in 5 times, when weight was the covariate used in the data generating mechanism. In a second simulation, parent drug concentration and three metabolites were simulated from a thorough QT study and used as covariates in a series of univariate linear mixed effects models of ddQTc interval prolongation. The covariate with the largest significant LRT statistic was deemed the "best" predictor. When the metabolite was formation-rate limited and only parent concentrations affected ddQTc intervals the metabolite was chosen as a better predictor as often as 1 in 5 times depending on the slope of the relationship between parent concentrations and ddQTc intervals. A correlated covariate can be chosen as being a better predictor than another covariate in a linear or nonlinear population analysis by sheer correlation These results explain why for the same drug different covariates may be identified in different analyses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Outcome and prognostic factors in single brain metastases from small-cell lung cancer.

PubMed

Bernhardt, Denise; Adeberg, Sebastian; Bozorgmehr, Farastuk; Opfermann, Nils; Hörner-Rieber, Juliane; König, Laila; Kappes, Jutta; Thomas, Michael; Unterberg, Andreas; Herth, Felix; Heußel, Claus Peter; Warth, Arne; Debus, Jürgen; Steins, Martin; Rieken, Stefan

2018-02-01

Whole brain radiation therapy (WBRT) is historically the standard of care for patients with brain metastases (BM) from small-cell lung cancer (SCLC), although locally ablative treatments are the standard of care for patients with 1-4 BM from other solid tumors. The objective of this analysis was to find prognostic factors influencing overall survival (OS) and intracranial progression-free survival (iPFS) in SCLC patients with single BM (SBM) treated with WBRT. A total of 52 patients were identified in the authors' cancer center database with histologically confirmed SCLC and contrast-enhanced magnet resonance imaging (MRI) or computed tomography (CT), which confirmed SBM between 2006 and 2015 and were therefore treated with WBRT. A Kaplan-Meier survival analysis was performed for OS analyses. The log-rank (Mantel-Cox) test was used to compare survival curves. Univariate Cox proportional-hazards ratios (HRs) were used to assess the influence of cofactors on OS and iPFS. The median OS after WBRT was 5 months and the median iPFS after WBRT 16 months. Patients that received surgery prior to WBRT had a significantly longer median OS of 19 months compared to 5 months in the group receiving only WBRT (p = 0.03; HR 2.24; 95% confidence interval [CI] 1.06-4.73). Patients with synchronous disease had a significantly longer OS compared to patients with metachronous BM (6 months vs. 3 months, p = 0.005; HR 0.27; 95% CI 0.11-0.68). Univariate analysis for OS revealed a statistically significant effect for metachronous disease (HR 2.25; 95% CI 1.14-4.46; p = 0.019), initial response to first-line chemotherapy (HR 0.58; 95% CI 0.35-0.97; p = 0.04), and surgical resection (HR 0.36; 95% CI 0.15-0.88; p = 0.026). OS was significantly affected by metachronous disease in multivariate analysis (HR 2.20; 95% CI 1.09-4.45; p = 0.028). Univariate analysis revealed that surgery followed by WBRT can improve OS in patients with SBM in SCLC. Furthermore, synchronous disease and response to initial chemotherapy appeared to be major prognostic factors. Multivariate analysis revealed metachronous disease as a significantly negative prognostic factor on OS. The value of WBRT, stereotactic radiosurgery (SRS), or surgery alone or in combination for patients with a limited number of BM in SCLC should be evaluated in further prospective clinical trials.

Assessment of water quality parameters using multivariate analysis for Klang River basin, Malaysia.

PubMed

Mohamed, Ibrahim; Othman, Faridah; Ibrahim, Adriana I N; Alaa-Eldin, M E; Yunus, Rossita M

2015-01-01

This case study uses several univariate and multivariate statistical techniques to evaluate and interpret a water quality data set obtained from the Klang River basin located within the state of Selangor and the Federal Territory of Kuala Lumpur, Malaysia. The river drains an area of 1,288 km(2), from the steep mountain rainforests of the main Central Range along Peninsular Malaysia to the river mouth in Port Klang, into the Straits of Malacca. Water quality was monitored at 20 stations, nine of which are situated along the main river and 11 along six tributaries. Data was collected from 1997 to 2007 for seven parameters used to evaluate the status of the water quality, namely dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, suspended solids, ammoniacal nitrogen, pH, and temperature. The data were first investigated using descriptive statistical tools, followed by two practical multivariate analyses that reduced the data dimensions for better interpretation. The analyses employed were factor analysis and principal component analysis, which explain 60 and 81.6% of the total variation in the data, respectively. We found that the resulting latent variables from the factor analysis are interpretable and beneficial for describing the water quality in the Klang River. This study presents the usefulness of several statistical methods in evaluating and interpreting water quality data for the purpose of monitoring the effectiveness of water resource management. The results should provide more straightforward data interpretation as well as valuable insight for managers to conceive optimum action plans for controlling pollution in river water.

Disability in physical education textbooks: an analysis of image content.

PubMed

Táboas-Pais, María Inés; Rey-Cao, Ana

2012-10-01

The aim of this paper is to show how images of disability are portrayed in physical education textbooks for secondary schools in Spain. The sample was composed of 3,316 images published in 36 textbooks by 10 publishing houses. A content analysis was carried out using a coding scheme based on categories employed in other similar studies and adapted to the requirements of this study with additional categories. The variables were camera angle, gender, type of physical activity, field of practice, space, and level. Univariate and bivariate descriptive analyses were also carried out. The Pearson chi-square statistic was used to identify associations between the variables. Results showed a noticeable imbalance between people with disabilities and people without disabilities, and women with disabilities were less frequently represented than men with disabilities. People with disabilities were depicted as participating in a very limited variety of segregated, competitive, and elite sports activities.

Fungal neuroinfections and fungaemia: unexpected increase of mortality from invasive fungal infections in 2005-2011 in comparison to 1989-1998: analysis of 210 cases.

PubMed

Demitrovicova, Andrea; Liskova, Anna; Valach, Michal; Izakovic, Martin; Noge, Adriana; Baranova, Jana; Kalatova, Dagmar; Syrovatkova, Ludmila; Velicova, Jana; Bugykova, Beata; Gulasova, Ivica; Seinova, Dagmar; Mikolasova, Gertruda; Mutalova, Martina; Pilkova, Martina; Szabo, Ivan; Findova, Lubica; Madarasz, Istvan; Stanzyk, Martin; Mikulickova, Dagmar; Blazekova, Maria; Jankechova, Monika; Slezakova, Zuzana; Kuriplachova, Gabriela; Visnovsky, Jozef; Obrocnikova, Andrea; Blumm, Mathias; Blumm, Bernard; Wolfram, Simon; Zeleny, Peter; Otrubova, Jana; Rudinsky, Bruno; Nagyova, Zuzana; Vravcova, Martina; Kajaba, Jozef; Jexova, Sona; Oravec, Svetoslav; Toth, Slavomir; Klobucka, Stanislava; Gerigh, Jana; Schumann, Frank; Ambra, Robert; Bandura, Peter; Bonnack, Christian; Kubisova, Zuzana; Palo, Marek; Kalavsky, Erich; Drgona, Lubos; Mahesvaari, Rajoo; Riedl, Jan

2013-09-01

In this short communication we compared the data of fungaemia cases in Slovak hospitals from 1989-1998 published in 1999-2000 with data from 2005-2011. Risk factors, etiology and outcome of fungaemia between two periods (1989-1998 vs. 2005-2011) were compared and risk factors for death assessed by univariate analysis (CDC 2006 Statistical Package). In comparison to 1989-1998 when only amphotericin B and fluconazole has been used (55%), in 2005-2011 only 35.2% patients received FLU, but 26.4% received voriconazole, 22% caspofungin and anidulafungin and about 6.6% lipid formulations of Amphotericin B. In etiology, while in 1989-1998 only 37.1% (115/310) represented non-albicans Candida (NAC) and non-Candida yeasts in 2005-2011 already reached 63.7%. The significant increase of breakthrough fungaemia may be a sign of inappropriate empiric therapy.

First and recurrent pediatric urinary tract infections: do they have different antibiotic susceptibilities?

PubMed

Narchi, H; Al-Hamdani, M

2008-08-01

Antibiotic susceptibility studies in children rarely differentiate between first and recurrent urinary tract infections (UTI), although the latter, frequently associated with underlying urinary tract anomalies and antibiotic prophylaxis, are more likely to be associated with higher antibiotic resistance of uropathogens as a result. We investigated whether antibiotic resistance was different between first and recurrent UTIs in 250 episodes (145 first and 105 recurrent) in 154 children (2 months to 12 years of age) with culture proven UTI. According to univariate analysis, resistance to cefuroxime and gentamicin was significantly lower in recurrences. This association remained statistically significant in the multivariable analysis, with adjusted odds ratio OR of 0.8 for cefuroxime (p=0.04) and for gentamicin (p=0.003) after adjusting for the role of confounding factors. The risk of resistance to other antibiotics was otherwise similar for first and recurrent UTIs.

Factors associated with inadequate fine motor skills in Brazilian students of different socioeconomic status.

PubMed

Bobbio, Tatiana Godoy; Morcillo, André Moreno; Barros Filho, Antonio de Azevedo; Concalves, Vanda Maria Gimenes

2007-12-01

The objective of this study was to evaluate and compare the motor coordination of Brazilian schoolchildren of different socioeconomic status in their first year of primary education. Factors associated with inadequate fine motor skills were identified. A total of 238 schoolchildren, 118 from a public school and 120 from a private school, were evaluated on fine motor skills using the Evolutional Neurological Examination. Statistical analysis was performed using univariate logistic regression followed by multivariate analysis. Children attending public school had a 5.5-fold greater risk of having inadequate fine motor skills for their age compared to children attending private school, while children who started school after four years of age had a 2.8-fold greater risk of having inadequate motor coordination compared to children who began school earlier. Data for this sample suggest socioeconomic factors and later entry of children to school may be associated with their fine motor skills.

Confronting Compassion Fatigue: Assessment and Intervention in Inpatient Oncology
.

PubMed

Zajac, Lisa M; Moran, Katherine J; Groh, Carla J

2017-08-01

A notable variation among patient satisfaction scores with nursing care was identified. Contributing factors were examined and revealed significant negative correlations between the unit death rate and surviving patients' satisfaction scores. Compassion fatigue (CF) was hypothesized to be a major contributing factor.
. The objective was to address CF in RNs and oncology care associates (assistive personnel) by developing an intervention to provide bereavement support to staff after patient deaths.
. A mixed-methods sequential design was used. Instruments included the Professional Quality of Life scale and Press Ganey survey results. Univariate descriptive statistics, frequencies, an independent t test, and an analysis of covariance were used for data analysis.
. The preintervention results revealed average compassion satisfaction and secondary traumatic stress scores and low burnout scores. No significant difference was noted between pre- and postintervention CF scores. Patients' perception of nurses' skills improved significantly in the second quarter of 2015.

Temperature and Humidity Effects on Hospital Morbidity in Darwin, Australia.

PubMed

Goldie, James; Sherwood, Steven C; Green, Donna; Alexander, Lisa

2015-01-01

Many studies have explored the relationship between temperature and health in the context of a changing climate, but few have considered the effects of humidity, particularly in tropical locations, on human health and well-being. To investigate this potential relationship, this study assessed the main and interacting effects of daily temperature and humidity on hospital admission rates for selected heat-relevant diagnoses in Darwin, Australia. Univariate and bivariate Poisson generalized linear models were used to find statistically significant predictors and the admission rates within bins of predictors were compared to explore nonlinear effects. The analysis indicated that nighttime humidity was the most statistically significant predictor (P < 0.001), followed by daytime temperature and average daily humidity (P < 0.05). There was no evidence of a significant interaction between them or other predictors. The nighttime humidity effect appeared to be strongly nonlinear: Hot days appeared to have higher admission rates when they were preceded by high nighttime humidity. From this analysis, we suggest that heat-health policies in tropical regions similar to Darwin need to accommodate the effects of temperature and humidity at different times of day. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Flexible Magnets Are Not Effective in Decreasing Pain Perception and Recovery Time After Muscle Microinjury

PubMed Central

Borsa, Paul A.; Liggett, Charles L.

1998-01-01

Objective: To assess the therapeutic effects of flexible magnets on pain perception, intramuscular swelling, range of motion, and muscular strength in individuals with a muscle microinjury. Design and Setting: This experiment was a single-blind, placebo study using a repeated-measures design. Subjects performed an intense exercise protocol to induce a muscle microinjury. After pretreatment measurements were recorded, subjects were randomly assigned to an experimental (magnet), placebo (imitation magnet), or control (no magnet) group. Posttreatment measurements were repeated at 24, 48, and 72 hours. Subjects: Forty-five healthy subjects participated in the study. Measurements: Subjects were measured repeatedly for pain perception, upper arm girth, range of motion, and static force production. Four separate univariate analyses of variances were used to reveal statistically significant mean (±SD) differences between variables over time. Interaction effects were analyzed using Scheffe post hoc analysis. Results: Analysis of variance revealed no statistically significant (P > .05) mean differences between conditions for any dependent pretreatment and posttreatment measurements. No significant interaction effects were demonstrated between conditions and times. Conclusions: No significant therapeutic effects on pain control and muscular dysfunction were observed in subjects wearing flexible magnets. ImagesFig 2.Fig 3. PMID:16558503

Survival analysis of colorectal cancer patients with tumor recurrence using global score test methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zain, Zakiyah, E-mail: zac@uum.edu.my; Ahmad, Yuhaniz, E-mail: yuhaniz@uum.edu.my; Azwan, Zairul, E-mail: zairulazwan@gmail.com, E-mail: farhanaraduan@gmail.com, E-mail: drisagap@yahoo.com

Colorectal cancer is the third and the second most common cancer worldwide in men and women respectively, and the second in Malaysia for both genders. Surgery, chemotherapy and radiotherapy are among the options available for treatment of patients with colorectal cancer. In clinical trials, the main purpose is often to compare efficacy between experimental and control treatments. Treatment comparisons often involve several responses or endpoints, and this situation complicates the analysis. In the case of colorectal cancer, sets of responses concerned with survival times include: times from tumor removal until the first, the second and the third tumor recurrences, andmore » time to death. For a patient, the time to recurrence is correlated to the overall survival. In this study, global score test methodology is used in combining the univariate score statistics for comparing treatments with respect to each survival endpoint into a single statistic. The data of tumor recurrence and overall survival of colorectal cancer patients are taken from a Malaysian hospital. The results are found to be similar to those computed using the established Wei, Lin and Weissfeld method. Key factors such as ethnic, gender, age and stage at diagnose are also reported.« less

Survival analysis of colorectal cancer patients with tumor recurrence using global score test methodology

NASA Astrophysics Data System (ADS)

Zain, Zakiyah; Aziz, Nazrina; Ahmad, Yuhaniz; Azwan, Zairul; Raduan, Farhana; Sagap, Ismail

2014-12-01

Colorectal cancer is the third and the second most common cancer worldwide in men and women respectively, and the second in Malaysia for both genders. Surgery, chemotherapy and radiotherapy are among the options available for treatment of patients with colorectal cancer. In clinical trials, the main purpose is often to compare efficacy between experimental and control treatments. Treatment comparisons often involve several responses or endpoints, and this situation complicates the analysis. In the case of colorectal cancer, sets of responses concerned with survival times include: times from tumor removal until the first, the second and the third tumor recurrences, and time to death. For a patient, the time to recurrence is correlated to the overall survival. In this study, global score test methodology is used in combining the univariate score statistics for comparing treatments with respect to each survival endpoint into a single statistic. The data of tumor recurrence and overall survival of colorectal cancer patients are taken from a Malaysian hospital. The results are found to be similar to those computed using the established Wei, Lin and Weissfeld method. Key factors such as ethnic, gender, age and stage at diagnose are also reported.

Safety in ready mixed concrete industry: descriptive analysis of injuries and development of preventive measures.

PubMed

Akboğa, Özge; Baradan, Selim

2017-02-07

Ready mixed concrete (RMC) industry, one of the barebones of construction sector, has its distinctive occupational safety and health (OSH) risks. Employees experience risks that emerge during the fabrication of concrete, as well as its delivery to the construction site. Statistics show that usage and demand of RMC have been increasing along with the number of producers and workers. Unfortunately, adequate OSH measures to meet this rapid growth are not in place even in top RMC producing countries, such as Turkey. Moreover, lack of statistical data and academic research in this sector exacerbates this problem. This study aims to fill this gap by conducting data mining in Turkish Social Security Institution archives and performing univariate frequency and cross tabulation analysis on 71 incidents that RMC truck drivers were involved. Also, investigations and interviews were conducted in seven RMC plants in Turkey and Netherlands with OSH point of view. Based on the results of this research, problem areas were determined such as; cleaning truck mixer/pump is a hazardous activity where operators get injured frequently, and struck by falling objects is a major hazard at RMC industry. Finally, Job Safety Analyses were performed on these areas to suggest mitigation methods.

Coping with confounds in multivoxel pattern analysis: what should we do about reaction time differences? A comment on Todd, Nystrom & Cohen 2013.

PubMed

Woolgar, Alexandra; Golland, Polina; Bode, Stefan

2014-09-01

Multivoxel pattern analysis (MVPA) is a sensitive and increasingly popular method for examining differences between neural activation patterns that cannot be detected using classical mass-univariate analysis. Recently, Todd et al. ("Confounds in multivariate pattern analysis: Theory and rule representation case study", 2013, NeuroImage 77: 157-165) highlighted a potential problem for these methods: high sensitivity to confounds at the level of individual participants due to the use of directionless summary statistics. Unlike traditional mass-univariate analyses where confounding activation differences in opposite directions tend to approximately average out at group level, group level MVPA results may be driven by any activation differences that can be discriminated in individual participants. In Todd et al.'s empirical data, factoring out differences in reaction time (RT) reduced a classifier's ability to distinguish patterns of activation pertaining to two task rules. This raises two significant questions for the field: to what extent have previous multivoxel discriminations in the literature been driven by RT differences, and by what methods should future studies take RT and other confounds into account? We build on the work of Todd et al. and compare two different approaches to remove the effect of RT in MVPA. We show that in our empirical data, in contrast to that of Todd et al., the effect of RT on rule decoding is negligible, and results were not affected by the specific details of RT modelling. We discuss the meaning of and sensitivity for confounds in traditional and multivoxel approaches to fMRI analysis. We observe that the increased sensitivity of MVPA comes at a price of reduced specificity, meaning that these methods in particular call for careful consideration of what differs between our conditions of interest. We conclude that the additional complexity of the experimental design, analysis and interpretation needed for MVPA is still not a reason to favour a less sensitive approach. Copyright © 2014 Elsevier Inc. All rights reserved.

Kalman filter for statistical monitoring of forest cover across sub-continental regions [Symposium

Treesearch

Raymond L. Czaplewski

1991-01-01

The Kalman filter is a generalization of the composite estimator. The univariate composite estimate combines 2 prior estimates of population parameter with a weighted average where the scalar weight is inversely proportional to the variances. The composite estimator is a minimum variance estimator that requires no distributional assumptions other than estimates of the...

Creating Realistic Data Sets with Specified Properties via Simulation

ERIC Educational Resources Information Center

Goldman, Robert N.; McKenzie, John D. Jr.

2009-01-01

We explain how to simulate both univariate and bivariate raw data sets having specified values for common summary statistics. The first example illustrates how to "construct" a data set having prescribed values for the mean and the standard deviation--for a one-sample t test with a specified outcome. The second shows how to create a bivariate data…

Departure from Normality in Multivariate Normative Comparison: The Cramer Alternative for Hotelling's "T[squared]"

ERIC Educational Resources Information Center

Grasman, Raoul P. P. P.; Huizenga, Hilde M.; Geurts, Hilde M.

2010-01-01

Crawford and Howell (1998) have pointed out that the common practice of z-score inference on cognitive disability is inappropriate if a patient's performance on a task is compared with relatively few typical control individuals. Appropriate univariate and multivariate statistical tests have been proposed for these studies, but these are only valid…

Higher rates of metabolic syndrome among women taking zidovudine as compared to tenofovir in rural Africa: preliminary data from the CART-1 study.

PubMed

Labhardt, Niklaus Daniel; Cheleboi, Molisana; Faturyiele, Olatunbosun; Motlatsi, Mokete M; Pfeiffer, Karolin; Lejone, Thabo Ismael; Cerutti, Bernard; Muser, Jürgen; Gupta, Ravi Shankar; Lynen, Lutgarde; Hatz, Christoph

2014-01-01

Due to its side effects stavudine (D4T) has been replaced by zidovudine (AZT) and tenofovir (TDF) in most low- and middle-income countries (LMICs). In 2014 about 38% of adult first-line regimens contain AZT and 62% TDF [1]. Whereas the unfavourable metabolic outcomes of D4T in comparison to TDF have been described extensively, studies from LMICs comparing metabolic profiles between patients on AZT and TDF are scarce. Given the high number of patients in LMICs still taking AZT, data on their metabolic profile are needed. We present rates of metabolic syndrome (MS) in adult patients taking either AZT- or TDF-containing first-line, non-nucleoside reverse transcriptase (NNRTI)-based regimens. Data derived from a cross-sectional multi-disease screening conducted in ten facilities in two rural districts of Lesotho, Southern Africa [2]. Patients were eligible if aged ≥25 years and on NNRTI-containing first-line ART ≥6 months. The MS definition for Africa of the International Diabetes Federation was applied [3]. Assessed potential predictors for MS were age, time on ART, virologic suppression, body-mass index (BMI), alcohol consumption, wealth quintile, NNRTI (nevirapine (NVP) or Efavirenz (EFV)), history of previous D4T exposure and ART-backbone (AZT or TDF). Statistical analyses - stratified for sex - comprised univariate logistic regression for each predictor variable with subsequent construction of a multivariate model including all predictors with an association to MS at a significance level<0.1 in univariate analysis. Out of 1026 patients, 660 (64.3%) were female. MS prevalence was 9.8% (95% CI 6.9-13.4) in men and 22.9% (19.7-26.3) in women. In women, aged ≥35 years, AZT-backbone, NVP-base, BMI ≥25kg/m2 and taking ART for ≥4.5 years were associated with MS in univariate analysis. In the multivariate model only AZT (adjusted odds-ratio: 2.2, 95% CI 1.4-3.6; p=0.001) and BMI ≥25kg/m2 (9.8; 2.8-34.1, p<0.001) were associated with MS. For men, age, higher wealth quintile, history of D4T exposure and BMI were associated with MS in univariate analysis. In the multivariate model only a BMI ≥25kg/m2 was associated with MS (8.9; 3.8-20.9, p<0.001). In rural Lesotho, Southern Africa, the use of AZT instead of TDF among women who are on ART for ≥6 months predisposes to the development of metabolic syndrome. Given that, still 38% of first-line regimens in LMIC contain AZT, this finding needs to be verified in other settings in Sub-Saharan Africa.

Deformable image registration as a tool to improve survival prediction after neoadjuvant chemotherapy for breast cancer: results from the ACRIN 6657/I-SPY-1 trial

NASA Astrophysics Data System (ADS)

Jahani, Nariman; Cohen, Eric; Hsieh, Meng-Kang; Weinstein, Susan P.; Pantalone, Lauren; Davatzikos, Christos; Kontos, Despina

2018-02-01

We examined the ability of DCE-MRI longitudinal features to give early prediction of recurrence-free survival (RFS) in women undergoing neoadjuvant chemotherapy for breast cancer, in a retrospective analysis of 106 women from the ISPY 1 cohort. These features were based on the voxel-wise changes seen in registered images taken before treatment and after the first round of chemotherapy. We computed the transformation field using a robust deformable image registration technique to match breast images from these two visits. Using the deformation field, parametric response maps (PRM) — a voxel-based feature analysis of longitudinal changes in images between visits — was computed for maps of four kinetic features (signal enhancement ratio, peak enhancement, and wash-in/wash-out slopes). A two-level discrete wavelet transform was applied to these PRMs to extract heterogeneity information about tumor change between visits. To estimate survival, a Cox proportional hazard model was applied with the C statistic as the measure of success in predicting RFS. The best PRM feature (as determined by C statistic in univariable analysis) was determined for each of the four kinetic features. The baseline model, incorporating functional tumor volume, age, race, and hormone response status, had a C statistic of 0.70 in predicting RFS. The model augmented with the four PRM features had a C statistic of 0.76. Thus, our results suggest that adding information on the texture of voxel-level changes in tumor kinetic response between registered images of first and second visits could improve early RFS prediction in breast cancer after neoadjuvant chemotherapy.

Assessment of Coastal and Urban Flooding Hazards Applying Extreme Value Analysis and Multivariate Statistical Techniques: A Case Study in Elwood, Australia

NASA Astrophysics Data System (ADS)

Guimarães Nobre, Gabriela; Arnbjerg-Nielsen, Karsten; Rosbjerg, Dan; Madsen, Henrik

2016-04-01

Traditionally, flood risk assessment studies have been carried out from a univariate frequency analysis perspective. However, statistical dependence between hydrological variables, such as extreme rainfall and extreme sea surge, is plausible to exist, since both variables to some extent are driven by common meteorological conditions. Aiming to overcome this limitation, multivariate statistical techniques has the potential to combine different sources of flooding in the investigation. The aim of this study was to apply a range of statistical methodologies for analyzing combined extreme hydrological variables that can lead to coastal and urban flooding. The study area is the Elwood Catchment, which is a highly urbanized catchment located in the city of Port Phillip, Melbourne, Australia. The first part of the investigation dealt with the marginal extreme value distributions. Two approaches to extract extreme value series were applied (Annual Maximum and Partial Duration Series), and different probability distribution functions were fit to the observed sample. Results obtained by using the Generalized Pareto distribution demonstrate the ability of the Pareto family to model the extreme events. Advancing into multivariate extreme value analysis, first an investigation regarding the asymptotic properties of extremal dependence was carried out. As a weak positive asymptotic dependence between the bivariate extreme pairs was found, the Conditional method proposed by Heffernan and Tawn (2004) was chosen. This approach is suitable to model bivariate extreme values, which are relatively unlikely to occur together. The results show that the probability of an extreme sea surge occurring during a one-hour intensity extreme precipitation event (or vice versa) can be twice as great as what would occur when assuming independent events. Therefore, presuming independence between these two variables would result in severe underestimation of the flooding risk in the study area.

Comorbidity measurement in patients with laryngeal squamous cell carcinoma.

PubMed

Castro, Mario A F; Dedivitis, Rogério A; Ribeiro, Karina C B

2007-01-01

The evaluation of a cancer patient can be affected by many factors. Cancer patients often have other diseases or medical conditions in addition to their cancer. These conditions are referred to as comorbidities. They can influence the treatment option, the rate of complications, the outcome, and can confound the survival analysis. It was the aim of this study to measure comorbidities in patients with laryngeal squamous cell carcinoma. Ninety adult patients treated for newly diagnosed laryngeal squamous cell carcinoma were studied. We measured comorbid illness applying the following validated scales: the Cumulative Illness Rating Scale (CIRS), the Kaplan-Feinstein Classification (KFC), the Charlson index, the Index of Coexistent Disease (ICED), the Adult Comorbidity Evaluation-27 (ACE-27), the Alcohol-Tobacco-Related Comorbidities Index (ATC), and the Washington University Head and Neck Comorbidity Index (WUHNCI). Survival analysis was performed using the Kaplan-Meier method (with the log-rank test value being used to compare groups). The Cox proportional hazards model was chosen to identify independent prognostic factors. The mean age was 62.3 years. The majority of patients (36.7%) had early tumors. Forty patients were treated by surgery only, while the remaining 49 patients also received postoperative radiation therapy. Only 5 patients (5.6%) were lost to follow-up. Median follow-up time was 42.5 months. The 4-year overall survival was 63%. There was a statistically significant difference between survival rates according to clinical stage (CS I 87.3%, CS II 48.9%, CS III 74.7%, CS IV 23.9%; p < 0.001). Patients treated by surgery only presented a better survival rate (79.6%) than those receiving postoperative radiation therapy (48.9%; p = 0.001). A statistically significant difference in survival rates was also noted when patients were analyzed according to the type of surgical procedure. In a univariate analysis, comorbidity had impact on prognosis, no matter which scale was utilized: CIRS (p = 0.008), ACE-27 (p = 0.010), ATC (p = 0.004), WUHNCI (p = 0.003), Charlson index (p = 0.020), KFC (p = 0.001), and ICED (p = 0.010). However, in the multivariate analysis, only CIRS and TNM staging were identified as independent prognostic factors. The comorbidity is an independent prognostic factor in patients with surgically treated laryngeal cancer. In the univariate analysis, all indexes were able to stratify patients. However, in the multiple analysis, only the CIRS was predictive of death. Comorbidities are an important factor in the analysis of overall survival. Copyright (c) 2007 S. Karger AG, Basel.

Is the prognostic significance of O6-methylguanine- DNA methyltransferase promoter methylation equally important in glioblastomas of patients from different continents? A systematic review with meta-analysis.

PubMed

Meng, Wei; Jiang, Yangyang; Ma, Jie

2017-01-01

O6-methylguanine-DNA methyltransferase (MGMT) is an independent predictor of therapeutic response and potential prognosis in patients with glioblastoma multiforme (GBM). However, its significance of clinical prognosis in different continents still needs to be explored. To explore the effects of MGMT promoter methylation on both progression-free survival (PFS) and overall survival (OS) among GBM patients from different continents, a systematic review of published studies was conducted. A total of 5103 patients from 53 studies were involved in the systematic review and the total percentage of MGMT promoter methylation was 45.53%. Of these studies, 16 studies performed univariate analyses and 17 performed multivariate analyses of MGMT promoter methylation on PFS. The pooled hazard ratio (HR) estimated for PFS was 0.55 (95% CI 0.50, 0.60) by univariate analysis and 0.43 (95% CI 0.38, 0.48) by multivariate analysis. The effect of MGMT promoter methylation on OS was explored in 30 studies by univariate analysis and in 30 studies by multivariate analysis. The combined HR was 0.48 (95% CI 0.44, 0.52) and 0.42 (95% CI 0.38, 0.45), respectively. In each subgroup divided by areas, the prognostic significance still remained highly significant. The proportion of methylation in each group was in inverse proportion to the corresponding HR in the univariate and multivariate analyses of PFS. However, from the perspective of OS, compared with data from Europe and the US, higher methylation rates in Asia did not bring better returns.

Cartilaginous Metabolomic Study Reveals Potential Mechanisms of Osteophyte Formation in Osteoarthritis.

PubMed

Xu, Zhongwei; Chen, Tingmei; Luo, Jiao; Ding, Shijia; Gao, Sichuan; Zhang, Jian

2017-04-07

Osteophyte is one of the inevitable consequences of progressive osteoarthritis with the main characteristics of cartilage degeneration and endochondral ossification. The pathogenesis of osteophyte formation is not fully understood to date. In this work, metabolomic approaches were employed to explore potential mechanisms of osteophyte formation by detecting metabolic variations between extracts of osteophyte cartilage tissues (n = 32) and uninvolved control cartilage tissues (n = 34), based on the platform of ultraperformance liquid chromatography tandem quadrupole time-of-flight mass spectrometry, as well as the use of multivariate statistic analysis and univariate statistic analysis. The osteophyte group was significantly separated from the control group by the orthogonal partial least-squares discriminant analysis models, indicating that metabolic state of osteophyte cartilage had been changed. In total, 28 metabolic variations further validated by mass spectrum (MS) match, tandom mass spectrum (MS/MS) match, and standards match mainly included amino acids, sulfonic acids, glycerophospholipids, and fatty acyls. These metabolites were related to some specific physiological or pathological processes (collagen dissolution, boundary layers destroyed, self-restoration triggered, etc.) which might be associated with the procedure of osteophyte formation. Pathway analysis showed phenylalanine metabolism (PI = 0.168, p = 0.004) was highly correlative to this degenerative process. Our findings provided a direction for targeted metabolomic study and an insight into further reveal the molecular mechanisms of ostophyte formation.

[Effect of occupational stress on mental health].

PubMed

Yu, Shan-fa; Zhang, Rui; Ma, Liang-qing; Gu, Gui-zhen; Yang, Yan; Li, Kui-rong

2003-02-01

To study the effect of job psychological demands and job control on mental health and their interaction. 93 male freight train dispatchers were evaluated by using revised Job Demand-Control Scale and 7 strain scales. Stepwise regression analysis, Univariate ANOVA, Kruskal-Wallis H and Modian methods were used in statistic analysis. Kruskal-Wallis H and Modian methods analysis revealed the difference in mental health scores among groups of decision latitude (mean rank 55.57, 47.95, 48.42, 33.50, P < 0.05), the differences in scores of mental health (37.45, 40.01, 58.35), job satisfaction (53.18, 46.91, 32.43), daily life strains (33.00, 44.96, 56.12) and depression (36.45, 42.25, 53.61) among groups of job time demands (P < 0.05) were all statistically significant. ANOVA showed that job time demands and decision latitude had interaction effects on physical complains (R(2) = 0.24), state-anxiety (R(2) = 0.26), and daytime fatigue (R(2) = 0.28) (P < 0.05). Regression analysis revealed a significant job time demands and job decision latitude interaction effect as well as significant main effects of the some independent variables on different job strains (R(2) > 0.05). Job time demands and job decision latitude have direct and interactive effects on psychosomatic health, the more time demands, the more psychological strains, the effect of job time demands is greater than that of job decision latitude.

Intratumoral heterogeneity analysis reveals hidden associations between protein expression losses and patient survival in clear cell renal cell carcinoma

PubMed Central

Devarajan, Karthik; Parsons, Theodore; Wang, Qiong; O'Neill, Raymond; Solomides, Charalambos; Peiper, Stephen C.; Testa, Joseph R.; Uzzo, Robert; Yang, Haifeng

2017-01-01

Intratumoral heterogeneity (ITH) is a prominent feature of kidney cancer. It is not known whether it has utility in finding associations between protein expression and clinical parameters. We used ITH that is detected by immunohistochemistry (IHC) to aid the association analysis between the loss of SWI/SNF components and clinical parameters.160 ccRCC tumors (40 per tumor stage) were used to generate tissue microarray (TMA). Four foci from different regions of each tumor were selected. IHC was performed against PBRM1, ARID1A, SETD2, SMARCA4, and SMARCA2. Statistical analyses were performed to correlate biomarker losses with patho-clinical parameters. Categorical variables were compared between groups using Fisher's exact tests. Univariate and multivariable analyses were used to correlate biomarker changes and patient survivals. Multivariable analyses were performed by constructing decision trees using the classification and regression trees (CART) methodology. IHC detected widespread ITH in ccRCC tumors. The statistical analysis of the “Truncal loss” (root loss) found additional correlations between biomarker losses and tumor stages than the traditional “Loss in tumor (total)”. Losses of SMARCA4 or SMARCA2 significantly improved prognosis for overall survival (OS). Losses of PBRM1, ARID1A or SETD2 had the opposite effect. Thus “Truncal Loss” analysis revealed hidden links between protein losses and patient survival in ccRCC. PMID:28445125

Comparison of Salmonella enteritidis phage types isolated from layers and humans in Belgium in 2005.

PubMed

Welby, Sarah; Imberechts, Hein; Riocreux, Flavien; Bertrand, Sophie; Dierick, Katelijne; Wildemauwe, Christa; Hooyberghs, Jozef; Van der Stede, Yves

2011-08-01

The aim of this study was to investigate the available results for Belgium of the European Union coordinated monitoring program (2004/665 EC) on Salmonella in layers in 2005, as well as the results of the monthly outbreak reports of Salmonella Enteritidis in humans in 2005 to identify a possible statistical significant trend in both populations. Separate descriptive statistics and univariate analysis were carried out and the parametric and/or non-parametric hypothesis tests were conducted. A time cluster analysis was performed for all Salmonella Enteritidis phage types (PTs) isolated. The proportions of each Salmonella Enteritidis PT in layers and in humans were compared and the monthly distribution of the most common PT, isolated in both populations, was evaluated. The time cluster analysis revealed significant clusters during the months May and June for layers and May, July, August, and September for humans. PT21, the most frequently isolated PT in both populations in 2005, seemed to be responsible of these significant clusters. PT4 was the second most frequently isolated PT. No significant difference was found for the monthly trend evolution of both PT in both populations based on parametric and non-parametric methods. A similar monthly trend of PT distribution in humans and layers during the year 2005 was observed. The time cluster analysis and the statistical significance testing confirmed these results. Moreover, the time cluster analysis showed significant clusters during the summer time and slightly delayed in time (humans after layers). These results suggest a common link between the prevalence of Salmonella Enteritidis in layers and the occurrence of the pathogen in humans. Phage typing was confirmed to be a useful tool for identifying temporal trends.

Smoking prevalence and seizure control in Chinese males with epilepsy.

PubMed

Gao, Hui; Sander, Josemir W; Du, Xudong; Chen, Jiani; Zhu, Cairong; Zhou, Dong

2017-08-01

Smoking has a negative effect on most diseases, yet it is under-investigated in people with epilepsy; thus its role is not clear in the general population with epilepsy. We performed a retrospective pilot study on males with epilepsy to determine the smoking rate and its relationship with seizure control using univariate analysis to calculate odds ratios (ORs) and also used a multi-variate logistic regression model. The smoking rate in our sample of 278 individuals was 25.5%, which is lower than the general Chinese population smoking rate among males of 52.1%. We used two classifications: the first classified epilepsy as generalized, or by presumed topographic origin (temporal, frontal, parietal and occipital). The second classified the dominant seizure type of an individual as generalized tonic clonic seizure (GTCS), myoclonic seizure (MS), complex partial seizure (CPS), simple partial seizure (SPS), and secondary GTCS (sGTCS). The univariable analysis of satisfactory seizure control profile and smoking rate in both classifications showed a trend towards a beneficial effect of smoking although most were not statistically significant. Considering medication is an important confounding factor that would largely influence seizure control, we also conducted multi-variable analysis for both classifications with drug numbers and dosage. The result of our model also suggested that smoking is a protective factor. Our findings seem to suggest that smoking could have a potential role in seizure control although confounders need exploration particularly in view of the potential long term health effects. Replication in a much larger sample is needed as well as case control studies to elucidate this issue. Copyright © 2017 Elsevier Inc. All rights reserved.

A single pre-operative antibiotic dose is as effective as continued antibiotic prophylaxis in implant-based breast reconstruction: A matched cohort study.

PubMed

Townley, William A; Baluch, Narges; Bagher, Shaghayegh; Maass, Saskia W M C; O'Neill, Anne; Zhong, Toni; Hofer, Stefan O P

2015-05-01

Infections following implant-based breast reconstruction can lead to devastating consequences. There is currently no consensus on the need for post-operative antibiotics in preventing immediate infection. This study compared two different methods of infection prevention in this group of patients. A retrospective matched cohort study was performed on consecutive women undergoing implant-based breast reconstruction at University Health Network, Toronto (November 2008-December 2012). All patients received a single pre-operative intravenous antibiotic dose. Group A received minimal interventions and Group B underwent maximal prophylactic measures. Patient (age, smoking, diabetes, co-morbidities), oncologic and procedural variables (timing and laterality) were collected. Univariate and multivariate logistic regression were performed to compare outcomes between the two groups. Two hundred and eight patients underwent 647 implant procedures. After matching the two treatment groups by BMI, 94 patients in each treatment group yielding a total of 605 implant procedures were selected for analysis. The two groups were comparable in terms of patient and disease variables. Post-operative wound infection was similar in Group A (n = 11, 12%) compared with Group B (n = 9, 10%; p = 0.8). Univariate analysis revealed only pre-operative radiotherapy to be associated with the development of infection (0.004). Controlling for the effect of radiotherapy, multivariate analysis demonstrated that there was no statistically significant difference between the two methods for infection prevention. Our findings suggest that a single pre-operative dose of intravenous antibiotics is equally as effective as continued antibiotic prophylaxis in preventing immediate infection in patients undergoing implant-based breast reconstructions. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Factors affecting surgical margin recurrence after hepatectomy for colorectal liver metastases

PubMed Central

Akyuz, Muhammet; Aucejo, Federico; Quintini, Cristiano; Miller, Charles; Fung, John

2016-01-01

Background Hepatic recurrence after resection of colorectal liver metastasis (CLM) occurs in 50% of patients during follow-up, with 2.8% to 13.9% presenting with surgical margin recurrence (SMR). The aim of this study is to analyze factors that related to SMR in patients with CLM undergoing hepatectomy. Methods Demographics, clinical and survival data of patients who underwent hepatectomy were identified from a prospectively maintained, institutional review board (IRB)-approved database between 2000 and 2012. Statistical analysis was performed using univariate Kaplan Meier and Cox proportional hazard model. Results There were 85 female and 121 male patients who underwent liver resection for CLM. An R0 resection was performed in 157 (76%) patients and R1 resection in 49. SMR was detected in 32 patients (15.5%) followed up for a median of 29 months (range, 3–121 months). A half of these patients had undergone R1 (n=16) and another half R0 resection (n=16). Tumor size, preoperative carcinoembryonic antigen (CEA) level and margin status were associated with SMR on univariate analysis. On multivariate analysis, a positive surgical margin was the only independent predictor of SMR. The receipt of adjuvant chemotherapy did not affect margin recurrence. SMR was an independent risk factor associated with worse disease-free (DFS) and overall survival (OS). Conclusions This study shows that SMR, which can be detected in up to 15.5% of patients after liver resection for CLM, adversely affects DFS and OS. The fact that a positive surgical margin was the only predictive factor for SMR in these patients underscores the importance of achieving negative margins during hepatectomy. PMID:27294032

Sternocleidomastoid myofascial flap for reconstruction after composite resection of invasive squamous cell carcinoma of the tonsillar region: technique and outcome.

PubMed

Laccourreye, Ollivier; Ménard, Madeleine; Behm, Eva; Garcia, Dominique; Cauchois, Régis; Holsinger, F Christopher

2006-11-01

To present the surgical technique and determine the efficacy of sternocleidomastoid myofascial (SCMF) flap reconstruction after composite resection with intent to cure. Retrospective review of 73 consecutive patients with a previously isolated and untreated moderately to well-differentiated invasive squamous cell carcinoma of the tonsillar region and a minimum of 3 years follow-up, managed at a tertiary referral care center during the years 1970 to 2002, with an ipsilateral superiorly based SCMF flap after composite resection. The surgical procedure is presented in detail. Potential technical pitfalls are highlighted. Survival, mortality, and morbidity are documented. Univariate analysis for potential correlation between the incidence for postoperative flap complications and various variables is also performed. The 1, 3, and 5 year Kaplan-Meier actuarial survival estimates were 82.2%, 64.4%, and 49.3%, respectively. Death never appeared to be related to the completion of the SCMF flap. Thirty-three (45.2%) patients had some kind of significant postoperative surgical complication, and nine (12.3%) patients had some kind of significant postoperative medical complication. The most common significant postoperative complication was partial SCMF flap necrosis and pharyngocutaneous fistula noted in 30.1% and 10.9% of patients, respectively. Complete SCMF flap necrosis was never encountered. No patient developed carotid artery rupture or died as a result of the SCMF flap, and none required additional surgery. In univariate analysis, no significant statistical relation was noted between the significant postoperative surgical complications related to the use of the SCMF flap and the variables under analysis. The superiorly based SCMF flap appears to be simple to perform and useful for reconstruction of defects after composite resection.

Esophageal wall dose-surface maps do not improve the predictive performance of a multivariable NTCP model for acute esophageal toxicity in advanced stage NSCLC patients treated with intensity-modulated (chemo-)radiotherapy.

PubMed

Dankers, Frank; Wijsman, Robin; Troost, Esther G C; Monshouwer, René; Bussink, Johan; Hoffmann, Aswin L

2017-05-07

In our previous work, a multivariable normal-tissue complication probability (NTCP) model for acute esophageal toxicity (AET) Grade  ⩾2 after highly conformal (chemo-)radiotherapy for non-small cell lung cancer (NSCLC) was developed using multivariable logistic regression analysis incorporating clinical parameters and mean esophageal dose (MED). Since the esophagus is a tubular organ, spatial information of the esophageal wall dose distribution may be important in predicting AET. We investigated whether the incorporation of esophageal wall dose-surface data with spatial information improves the predictive power of our established NTCP model. For 149 NSCLC patients treated with highly conformal radiation therapy esophageal wall dose-surface histograms (DSHs) and polar dose-surface maps (DSMs) were generated. DSMs were used to generate new DSHs and dose-length-histograms that incorporate spatial information of the dose-surface distribution. From these histograms dose parameters were derived and univariate logistic regression analysis showed that they correlated significantly with AET. Following our previous work, new multivariable NTCP models were developed using the most significant dose histogram parameters based on univariate analysis (19 in total). However, the 19 new models incorporating esophageal wall dose-surface data with spatial information did not show improved predictive performance (area under the curve, AUC range 0.79-0.84) over the established multivariable NTCP model based on conventional dose-volume data (AUC  =  0.84). For prediction of AET, based on the proposed multivariable statistical approach, spatial information of the esophageal wall dose distribution is of no added value and it is sufficient to only consider MED as a predictive dosimetric parameter.

Trainee-Associated Factors and Proficiency at Percutaneous Nephrolithotomy.

PubMed

Aghamir, Seyed Mohammad Kazem; Behtash, Negar; Hamidi, Morteza; Farahmand, Hasan; Salavati, Alborz; Mortaz Hejri, Sara

2017-07-01

Percutaneous nephrolithotomy (PNL) is a complicated procedure for urology trainees. This study was designed to investigate the effect of trainees' ages and previous experience, as well as the number of operated cases, on proficiency at PNL by using patient outcomes. A cross sectional observational study was designed during a five-year period. Trainees in PNL fellowship programs were included. At the end of the program, the trainees' performance in PNL was assessed regarding five competencies and scored 1-5. If the overall score was 4 or above, the trainee was considered as proficient. The trainees' age at the beginning of the program and the years passed from their residency graduation were asked and recorded. Also, the number of PNL cases operated by each trainee was obtained via their logbooks. The age, years passed from graduation, and number of operated cases were compared between two groups of proficient and non-proficient trainees. Univariate and multivariate binary logistic regression analysis was applied to estimate the effect of aforementioned variables on the occurrence of the proficiency. Forty-two trainees were included in the study. The mean and standard deviation for the overall score were 3.40 (out of 5) and 0.67, respectively. Eleven trainees (26.2%) recognized as proficient in performing PNL. Univariate regression analysis indicated that each of three variables (age, years passed from graduation and number of operated cases) had statistically significant effect on proficiency. However, the multivariate regression analysis revealed that just the number of cases had significant effect on achieving proficiency. Although it might be assumed that trainees' age negatively correlates with their scores, in fact, it is their amount of practice that makes a difference. A certain number of cases is required to be operated by a trainee in order to reach the desired competency in PNL.

Value of the Definition of Severe Familial Hypercholesterolemia for Stratification of Heterozygous Patients.

PubMed

Pérez-Calahorra, Sofia; Sánchez-Hernández, Rosa María; Plana, Núria; Marco-Benedi, Victoria; Pedro-Botet, Juan; Almagro, Fátima; Brea, Angel; Ascaso, Juan Francisco; Lahoz, Carlos; Civeira, Fernando

2017-03-01

Familial hypercholesterolemia (FH) is characterized by high low-density lipoprotein (LDL) cholesterol with co-dominant transmission and high risk of cardiovascular disease (CVD), although with high variability among subjects. Currently, CVD stratification tools for heterozygous FH (HeFH) are not available. A definition of severe HeFH has been recently proposed by the International Atherosclerosis Society (IAS), but it has not been validated. Our study aims to see clinical characteristics and prevalence of CVD in subjects defined as severe HeFH by IAS criteria. Probable or definite HeFH introduced in the Dyslipidemia Registry of Spanish Arteriosclerosis Society were analyzed by the IAS criteria. Univariate and multivariate analysis was used to assess the association of CVD with the IAS criteria. About 1,732 HeFH cases were analyzed. Severe HeFH had higher prevalence of familial history of CVD, personal history of tendon xanthomas, LDL cholesterol, and CVD than nonsevere HeFH. A total of 656 (77.1%) and 441 (50.1%) of men and women, respectively, fulfilled the IAS criteria of severe HeFH. In the univariate analysis, subjects defined as severe HeFH showed odds ratio 3.016 (95% CI 3.136 to 4.257, p <0.001) for CVD. However, when traditional risk factors were included in the multivariate analysis, only the presence of cholesterol >400 mg/dl had a statistically significant association with CVD odds ratio 8.76 (95% CI 3.90 to 19.69, p <0.001). In conclusion, the IAS definition of severe HeFH is not significantly associated with CVD when adjusted for classic risk factors. Risk stratification in HeFH is an important issue, but the proposed criteria do not seem to solve this problem. Copyright © 2016 Elsevier Inc. All rights reserved.

A Java-based fMRI processing pipeline evaluation system for assessment of univariate general linear model and multivariate canonical variate analysis-based pipelines.

PubMed

Zhang, Jing; Liang, Lichen; Anderson, Jon R; Gatewood, Lael; Rottenberg, David A; Strother, Stephen C

2008-01-01

As functional magnetic resonance imaging (fMRI) becomes widely used, the demands for evaluation of fMRI processing pipelines and validation of fMRI analysis results is increasing rapidly. The current NPAIRS package, an IDL-based fMRI processing pipeline evaluation framework, lacks system interoperability and the ability to evaluate general linear model (GLM)-based pipelines using prediction metrics. Thus, it can not fully evaluate fMRI analytical software modules such as FSL.FEAT and NPAIRS.GLM. In order to overcome these limitations, a Java-based fMRI processing pipeline evaluation system was developed. It integrated YALE (a machine learning environment) into Fiswidgets (a fMRI software environment) to obtain system interoperability and applied an algorithm to measure GLM prediction accuracy. The results demonstrated that the system can evaluate fMRI processing pipelines with univariate GLM and multivariate canonical variates analysis (CVA)-based models on real fMRI data based on prediction accuracy (classification accuracy) and statistical parametric image (SPI) reproducibility. In addition, a preliminary study was performed where four fMRI processing pipelines with GLM and CVA modules such as FSL.FEAT and NPAIRS.CVA were evaluated with the system. The results indicated that (1) the system can compare different fMRI processing pipelines with heterogeneous models (NPAIRS.GLM, NPAIRS.CVA and FSL.FEAT) and rank their performance by automatic performance scoring, and (2) the rank of pipeline performance is highly dependent on the preprocessing operations. These results suggest that the system will be of value for the comparison, validation, standardization and optimization of functional neuroimaging software packages and fMRI processing pipelines.

Predictors of Nodal Upstaging in Clinical Node Negative Patients With Penile Carcinoma: A National Cancer Database Analysis.

PubMed

Winters, Brian R; Mossanen, Matthew; Holt, Sarah K; Lin, Daniel W; Wright, Jonathan L

2016-10-01

To examine the risk factors associated with upstaging at inguinal lymph node dissection (ILND) in men with penile cancer and clinically negative lymph nodes (cN0) using a large US cancer database. The National Cancer Data Base was queried from 1998 to 2012 to identify men with penile cancer who underwent ILND and had complete clinical or pathologic node status available. Lymphovascular invasion (LVI) was available after 2010. Multivariate logistic regression evaluated factors (cT stage, grade, LVI) associated with pathologic nodal upstaging in those with cN0 disease. Correlations between clinical and pathologic node status were also calculated with weighted kappa statistics. Complete clinical and pathologic LN status was available for 875 patients. Of these, 461 (53%) were cN0. Upstaging occurred in 111 (24%). When stratified by low, intermediate, and high-risk groups, the proportion with pathologically positive LNs was 16%, 20%, and 27%, respectively (P = .12). On multivariate analysis, limited to men with LVI data available (N = 206), LVI (odds ratio 3.10, 95% confidence interval 1.39-6.92), but not increasing stage (univariate only) or grade (univariate only), was significantly associated with upstaging at ILND. In this analysis, of 461 patients with node-negative penile cancer undergoing ILND, upstaging was observed in 24%. LVI was the strongest independent predictor of occult lymph node disease. These findings corroborate the presence of LVI as the significant risk factor for occult micrometastases and suggest a possible improvement in existing risk stratification groupings, with the presence of LVI, regardless of stage or grade, to be considered high-risk disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Esophageal wall dose-surface maps do not improve the predictive performance of a multivariable NTCP model for acute esophageal toxicity in advanced stage NSCLC patients treated with intensity-modulated (chemo-)radiotherapy

NASA Astrophysics Data System (ADS)

Dankers, Frank; Wijsman, Robin; Troost, Esther G. C.; Monshouwer, René; Bussink, Johan; Hoffmann, Aswin L.

2017-05-01

In our previous work, a multivariable normal-tissue complication probability (NTCP) model for acute esophageal toxicity (AET) Grade  ⩾2 after highly conformal (chemo-)radiotherapy for non-small cell lung cancer (NSCLC) was developed using multivariable logistic regression analysis incorporating clinical parameters and mean esophageal dose (MED). Since the esophagus is a tubular organ, spatial information of the esophageal wall dose distribution may be important in predicting AET. We investigated whether the incorporation of esophageal wall dose-surface data with spatial information improves the predictive power of our established NTCP model. For 149 NSCLC patients treated with highly conformal radiation therapy esophageal wall dose-surface histograms (DSHs) and polar dose-surface maps (DSMs) were generated. DSMs were used to generate new DSHs and dose-length-histograms that incorporate spatial information of the dose-surface distribution. From these histograms dose parameters were derived and univariate logistic regression analysis showed that they correlated significantly with AET. Following our previous work, new multivariable NTCP models were developed using the most significant dose histogram parameters based on univariate analysis (19 in total). However, the 19 new models incorporating esophageal wall dose-surface data with spatial information did not show improved predictive performance (area under the curve, AUC range 0.79-0.84) over the established multivariable NTCP model based on conventional dose-volume data (AUC  =  0.84). For prediction of AET, based on the proposed multivariable statistical approach, spatial information of the esophageal wall dose distribution is of no added value and it is sufficient to only consider MED as a predictive dosimetric parameter.

CT and histopathologic characteristics of lung adenocarcinoma with pure ground-glass nodules 10 mm or less in diameter.

PubMed

Wu, Fang; Tian, Shu-Ping; Jin, Xin; Jing, Rui; Yang, Yue-Qing; Jin, Mei; Zhao, Shao-Hong

2017-10-01

To evaluate CT and histopathologic features of lung adenocarcinoma with pure ground-glass nodule (pGGN) ≤10 mm in diameter. CT appearances of 148 patients (150 lesions) who underwent curative resection of lung adenocarcinoma with pGGN ≤10 mm (25 atypical adenomatous hyperplasias, 42 adenocarcinoma in situs, 38 minimally invasive adenocarcinomas, and 45 invasive pulmonary adenocarcinomas) were analyzed for lesion size, density, bubble-like sign, air bronchogram, vessel changes, margin, and tumour-lung interface. CT characteristics were compared among different histopathologic subtypes. Univariate and multivariate analysis were used to assess the relationship between CT characteristics of pGGN and lesion invasiveness, respectively. There were statistically significant differences among histopathologic subtypes in lesion size, vessel changes, and tumour-lung interface (P<0.05). Univariate analysis revealed significant differences of vessel changes, margin and tumour-lung interface between preinvasive and invasive lesions (P<0.05). Logistic regression analysis showed that the vessel changes, unsmooth margin and clear tumour-lung interface were significant predictive factors for lesion invasiveness, with odds ratios (95% CI) of 2.57 (1.17-5.62), 1.83 (1.25-2.68) and 4.25 (1.78-10.14), respectively. Invasive lesions are found in 55.3% of subcentimeter pGGNs in our cohort. Vessel changes, unsmooth margin, and clear lung-tumour interface may indicate the invasiveness of lung adenocarcinoma with subcentimeter pGGN. • Invasive lesions were found in 55.3% of lung adenocarcinomas with subcentimeter pGGNs • Lesion size, vessel changes, and tumour-lung interface showed different among histopathologic subtypes • Vessel changes, unsmooth margin and clear tumour-lung interface were predictors for lesion invasiveness.

Does mental health staffing level affect antipsychotic prescribing? Analysis of Italian national statistics.

PubMed

Starace, Fabrizio; Mungai, Francesco; Barbui, Corrado

2018-01-01

In mental healthcare, one area of major concern identified by health information systems is variability in antipsychotic prescribing. While most studies have investigated patient- and prescriber-related factors as possible reasons for such variability, no studies have investigated facility-level characteristics. The present study ascertained whether staffing level is associated with antipsychotic prescribing in community mental healthcare. A cross-sectional analysis of data extracted from the Italian national mental health information system was carried out. For each Italian region, it collects data on the availability and use of mental health facilities. The rate of individuals exposed to antipsychotic drugs was tested for evidence of association with the rate of mental health staff availability by means of univariate and multivariate analyses. In Italy there were on average nearly 60 mental health professionals per 100,000 inhabitants, with wide regional variations (range 21 to 100). The average rate of individuals prescribed antipsychotic drugs was 2.33%, with wide regional variations (1.04% to 4.01%). Univariate analysis showed that the rate of individuals prescribed antipsychotic drugs was inversely associated with the rate of mental health professionals available in Italian regions (Kendall's tau -0.438, p = 0.006), with lower rates of antipsychotic prescriptions in regions with higher rates of mental health professionals. After adjustment for possible confounders, the total availability of mental health professionals was still inversely associated with the rate of individuals exposed to antipsychotic drugs. The evidence that staffing level was inversely associated with antipsychotic prescribing indicates that any actions aimed at decreasing variability in antipsychotic prescribing need to take into account aspects related to the organization of the mental health system.

Confidential donation confirmation as an alternative to confidential unit exclusion: 15 months experience of the HEMOMINAS foundation.

PubMed

Loureiro, Flávia Cristine Martineli; Oliveira, Cláudia Di Lorenzo; Proietti, Anna Bárbara F Carneiro; Proietti, Fernando Augusto

2011-01-01

Confidential unit exclusion remains a controversial strategy to reduce the residual risk of transfusion-transmitted infections. This study aimed to analyze confidential unit exclusion from its development in a large institution in light of confidential donation confirmation. Data of individuals who donated from October 1, 2008 to December 31, 2009 were analyzed in a case-control study. The serological results and sociodemographic characteristics of donors who did not confirm their donations were compared to those who did. Variables with p-values < 0.20 in univariate analysis were included in a logistic multivariate analysis. In the univariate analysis there was a statically significant association between positive serological results and response to confidential donation confirmation of "No". Donation type, (firsttime or return donor - OR 1.69, CI 1.37-2.09), gender (OR 1.66, CI 1.35-2.04), education level (OR 2.82, CI 2.30-3.47) and ethnic background (OR 0.67, CI 0.55-0.82) were included in the final logistic regression model. In all logistic regression models analyzed, the serological suitability and confidential donation confirmation were not found to be statistically associated. The adoption of new measures of clinical classification such as audiovisual touch-screen computer-assisted self-administered interviews might be more effective than confidential unit exclusion in the identification of donor risk behavior. The requirement that transfusion services continue to use confidential unit exclusion needs to be debated in countries where more specific and sensitive clinical and serological screening methods are available. Our findings suggest that there are not enough benefits to justify continued use of confidential donation confirmation in the analyzed institution.

Confidential donation confirmation as an alternative to confidential unit exclusion: 15 months experience of the HEMOMINAS foundation

PubMed Central

Loureiro, Flávia Cristine Martineli; Oliveira, Cláudia Di Lorenzo; Proietti, Anna Bárbara F. Carneiro; Proietti, Fernando Augusto

2011-01-01

Background Confidential unit exclusion remains a controversial strategy to reduce the residual risk of transfusion-transmitted infections. Objective This study aimed to analyze confidential unit exclusion from its development in a large institution in light of confidential donation confirmation. Methods Data of individuals who donated from October 1, 2008 to December 31, 2009 were analyzed in a case-control study. The serological results and sociodemographic characteristics of donors who did not confirm their donations were compared to those who did. Variables with p-values < 0.20 in univariate analysis were included in a logistic multivariate analysis. Results In the univariate analysis there was a statically significant association between positive serological results and response to confidential donation confirmation of "No". Donation type, (firsttime or return donor - OR 1.69, CI 1.37-2.09), gender (OR 1.66, CI 1.35-2.04), education level (OR 2.82, CI 2.30-3.47) and ethnic background (OR 0.67, CI 0.55-0.82) were included in the final logistic regression model. In all logistic regression models analyzed, the serological suitability and confidential donation confirmation were not found to be statistically associated. The adoption of new measures of clinical classification such as audiovisual touch-screen computer-assisted self-administered interviews might be more effective than confidential unit exclusion in the identification of donor risk behavior. The requirement that transfusion services continue to use confidential unit exclusion needs to be debated in countries where more specific and sensitive clinical and serological screening methods are available. Conclusion Our findings suggest that there are not enough benefits to justify continued use of confidential donation confirmation in the analyzed institution. PMID:23049316

Regression Is a Univariate General Linear Model Subsuming Other Parametric Methods as Special Cases.

ERIC Educational Resources Information Center

Vidal, Sherry

Although the concept of the general linear model (GLM) has existed since the 1960s, other univariate analyses such as the t-test and the analysis of variance models have remained popular. The GLM produces an equation that minimizes the mean differences of independent variables as they are related to a dependent variable. From a computer printout…

Multimodal Feature Integration in the Angular Gyrus during Episodic and Semantic Retrieval

PubMed Central

Bonnici, Heidi M.; Richter, Franziska R.; Yazar, Yasemin

2016-01-01

Much evidence from distinct lines of investigation indicates the involvement of angular gyrus (AnG) in the retrieval of both episodic and semantic information, but the region's precise function and whether that function differs across episodic and semantic retrieval have yet to be determined. We used univariate and multivariate fMRI analysis methods to examine the role of AnG in multimodal feature integration during episodic and semantic retrieval. Human participants completed episodic and semantic memory tasks involving unimodal (auditory or visual) and multimodal (audio-visual) stimuli. Univariate analyses revealed the recruitment of functionally distinct AnG subregions during the retrieval of episodic and semantic information. Consistent with a role in multimodal feature integration during episodic retrieval, significantly greater AnG activity was observed during retrieval of integrated multimodal episodic memories compared with unimodal episodic memories. Multivariate classification analyses revealed that individual multimodal episodic memories could be differentiated in AnG, with classification accuracy tracking the vividness of participants' reported recollections, whereas distinct unimodal memories were represented in sensory association areas only. In contrast to episodic retrieval, AnG was engaged to a statistically equivalent degree during retrieval of unimodal and multimodal semantic memories, suggesting a distinct role for AnG during semantic retrieval. Modality-specific sensory association areas exhibited corresponding activity during both episodic and semantic retrieval, which mirrored the functional specialization of these regions during perception. The results offer new insights into the integrative processes subserved by AnG and its contribution to our subjective experience of remembering. SIGNIFICANCE STATEMENT Using univariate and multivariate fMRI analyses, we provide evidence that functionally distinct subregions of angular gyrus (AnG) contribute to the retrieval of episodic and semantic memories. Our multivariate pattern classifier could distinguish episodic memory representations in AnG according to whether they were multimodal (audio-visual) or unimodal (auditory or visual) in nature, whereas statistically equivalent AnG activity was observed during retrieval of unimodal and multimodal semantic memories. Classification accuracy during episodic retrieval scaled with the trial-by-trial vividness with which participants experienced their recollections. Therefore, the findings offer new insights into the integrative processes subserved by AnG and how its function may contribute to our subjective experience of remembering. PMID:27194327

Multimodal Feature Integration in the Angular Gyrus during Episodic and Semantic Retrieval.

PubMed

Bonnici, Heidi M; Richter, Franziska R; Yazar, Yasemin; Simons, Jon S

2016-05-18

Much evidence from distinct lines of investigation indicates the involvement of angular gyrus (AnG) in the retrieval of both episodic and semantic information, but the region's precise function and whether that function differs across episodic and semantic retrieval have yet to be determined. We used univariate and multivariate fMRI analysis methods to examine the role of AnG in multimodal feature integration during episodic and semantic retrieval. Human participants completed episodic and semantic memory tasks involving unimodal (auditory or visual) and multimodal (audio-visual) stimuli. Univariate analyses revealed the recruitment of functionally distinct AnG subregions during the retrieval of episodic and semantic information. Consistent with a role in multimodal feature integration during episodic retrieval, significantly greater AnG activity was observed during retrieval of integrated multimodal episodic memories compared with unimodal episodic memories. Multivariate classification analyses revealed that individual multimodal episodic memories could be differentiated in AnG, with classification accuracy tracking the vividness of participants' reported recollections, whereas distinct unimodal memories were represented in sensory association areas only. In contrast to episodic retrieval, AnG was engaged to a statistically equivalent degree during retrieval of unimodal and multimodal semantic memories, suggesting a distinct role for AnG during semantic retrieval. Modality-specific sensory association areas exhibited corresponding activity during both episodic and semantic retrieval, which mirrored the functional specialization of these regions during perception. The results offer new insights into the integrative processes subserved by AnG and its contribution to our subjective experience of remembering. Using univariate and multivariate fMRI analyses, we provide evidence that functionally distinct subregions of angular gyrus (AnG) contribute to the retrieval of episodic and semantic memories. Our multivariate pattern classifier could distinguish episodic memory representations in AnG according to whether they were multimodal (audio-visual) or unimodal (auditory or visual) in nature, whereas statistically equivalent AnG activity was observed during retrieval of unimodal and multimodal semantic memories. Classification accuracy during episodic retrieval scaled with the trial-by-trial vividness with which participants experienced their recollections. Therefore, the findings offer new insights into the integrative processes subserved by AnG and how its function may contribute to our subjective experience of remembering. Copyright © 2016 Bonnici, Richter, et al.

What Can Influence Iranian Suicide Attempters to Go Through the Process of Non-Fatal Suicide Act Once Again? A Preliminary Report.

PubMed

Toudehskchuie, Gholam Reza Ghassemi; Fereidoon, Mahsa

2016-07-01

The thrust of this study was to examine some of the psycho-social risk factors for the recurrence of non-fatal suicide attempt in a sample of 1121 inmates admitted between April 2012 to June 2013 at the toxicology emergency ward, Noor Medical Centre, Isfahan, Iran. Out of the total participants, 240 of them reported history of suicide attempt and assumed the status of case group. The remaining 881 patients were admitted first their attempt and constituted the control group. Cases were compared to the controls with respect to select demographic features (i.e. age, sex, education, occupation, marital status, type of residence, and locale), current suicide attempt method, family history of suicide and drug abuse, history of psychiatric disorder, physical ailment and physical disability, substance abuse and alcohol use, psychiatric diagnosis, and recent life hassles (i.e. interpersonal, occupational, financial, medical, and home affairs). We used a structured interview schedule to interview the participants. Psychiatric diagnosis was based on the DSM-IV criteria. Data were computer analyzed using SPSS.21 and administering statistical analysis including Chi Square, t-student, and logistic regression. Demographic risk factors for recurrence of suicide attempts at the univariate level included occupational status [Crud odds Ratio (COR) = 0.53] and type of residence (COR = 1.40). Medical and psychiatric risk factors at the univariate level included substance abuse (COR = 1.97), physical ailment (COR = 1.76), alcohol use (COR = 1.84), psychiatric disorder (COR = 3.69), and history of suicide in the family of origin (COR = 1.86). Recent life hassles risk factors at the univariate level included financial constraints (COR = 1.46) and medical emergencies (COR = 3.48). A multivariate logistic regression model identified five variables (i.e. substance abuse, alcohol use, psychiatric illness, suicide in family, and medical emergencies) that were statistically associated with an increased risk for recurrence of nonfatal suicide attempt. The model predicted chances of repeating suicide attempt correctly 79 % of the time. These observations indicate that people who report to the toxicology emergency ward for nonfatal suicide not only need immediate relief but also careful psychiatric and social assessments which subsequently may lead to psychiatric admission and comprehensive community interventions.

The impact of multiple endpoint dependency on Q and I(2) in meta-analysis.

PubMed

Thompson, Christopher Glen; Becker, Betsy Jane

2014-09-01

A common assumption in meta-analysis is that effect sizes are independent. When correlated effect sizes are analyzed using traditional univariate techniques, this assumption is violated. This research assesses the impact of dependence arising from treatment-control studies with multiple endpoints on homogeneity measures Q and I(2) in scenarios using the unbiased standardized-mean-difference effect size. Univariate and multivariate meta-analysis methods are examined. Conditions included different overall outcome effects, study sample sizes, numbers of studies, between-outcomes correlations, dependency structures, and ways of computing the correlation. The univariate approach used typical fixed-effects analyses whereas the multivariate approach used generalized least-squares (GLS) estimates of a fixed-effects model, weighted by the inverse variance-covariance matrix. Increased dependence among effect sizes led to increased Type I error rates from univariate models. When effect sizes were strongly dependent, error rates were drastically higher than nominal levels regardless of study sample size and number of studies. In contrast, using GLS estimation to account for multiple-endpoint dependency maintained error rates within nominal levels. Conversely, mean I(2) values were not greatly affected by increased amounts of dependency. Last, we point out that the between-outcomes correlation should be estimated as a pooled within-groups correlation rather than using a full-sample estimator that does not consider treatment/control group membership. Copyright © 2014 John Wiley & Sons, Ltd.

Using structural equation modeling for network meta-analysis.

PubMed

Tu, Yu-Kang; Wu, Yun-Chun

2017-07-14

Network meta-analysis overcomes the limitations of traditional pair-wise meta-analysis by incorporating all available evidence into a general statistical framework for simultaneous comparisons of several treatments. Currently, network meta-analyses are undertaken either within the Bayesian hierarchical linear models or frequentist generalized linear mixed models. Structural equation modeling (SEM) is a statistical method originally developed for modeling causal relations among observed and latent variables. As random effect is explicitly modeled as a latent variable in SEM, it is very flexible for analysts to specify complex random effect structure and to make linear and nonlinear constraints on parameters. The aim of this article is to show how to undertake a network meta-analysis within the statistical framework of SEM. We used an example dataset to demonstrate the standard fixed and random effect network meta-analysis models can be easily implemented in SEM. It contains results of 26 studies that directly compared three treatment groups A, B and C for prevention of first bleeding in patients with liver cirrhosis. We also showed that a new approach to network meta-analysis based on the technique of unrestricted weighted least squares (UWLS) method can also be undertaken using SEM. For both the fixed and random effect network meta-analysis, SEM yielded similar coefficients and confidence intervals to those reported in the previous literature. The point estimates of two UWLS models were identical to those in the fixed effect model but the confidence intervals were greater. This is consistent with results from the traditional pairwise meta-analyses. Comparing to UWLS model with common variance adjusted factor, UWLS model with unique variance adjusted factor has greater confidence intervals when the heterogeneity was larger in the pairwise comparison. The UWLS model with unique variance adjusted factor reflects the difference in heterogeneity within each comparison. SEM provides a very flexible framework for univariate and multivariate meta-analysis, and its potential as a powerful tool for advanced meta-analysis is still to be explored.

Fast Genome-Wide QTL Association Mapping on Pedigree and Population Data.

PubMed

Zhou, Hua; Blangero, John; Dyer, Thomas D; Chan, Kei-Hang K; Lange, Kenneth; Sobel, Eric M

2017-04-01

Since most analysis software for genome-wide association studies (GWAS) currently exploit only unrelated individuals, there is a need for efficient applications that can handle general pedigree data or mixtures of both population and pedigree data. Even datasets thought to consist of only unrelated individuals may include cryptic relationships that can lead to false positives if not discovered and controlled for. In addition, family designs possess compelling advantages. They are better equipped to detect rare variants, control for population stratification, and facilitate the study of parent-of-origin effects. Pedigrees selected for extreme trait values often segregate a single gene with strong effect. Finally, many pedigrees are available as an important legacy from the era of linkage analysis. Unfortunately, pedigree likelihoods are notoriously hard to compute. In this paper, we reexamine the computational bottlenecks and implement ultra-fast pedigree-based GWAS analysis. Kinship coefficients can either be based on explicitly provided pedigrees or automatically estimated from dense markers. Our strategy (a) works for random sample data, pedigree data, or a mix of both; (b) entails no loss of power; (c) allows for any number of covariate adjustments, including correction for population stratification; (d) allows for testing SNPs under additive, dominant, and recessive models; and (e) accommodates both univariate and multivariate quantitative traits. On a typical personal computer (six CPU cores at 2.67 GHz), analyzing a univariate HDL (high-density lipoprotein) trait from the San Antonio Family Heart Study (935,392 SNPs on 1,388 individuals in 124 pedigrees) takes less than 2 min and 1.5 GB of memory. Complete multivariate QTL analysis of the three time-points of the longitudinal HDL multivariate trait takes less than 5 min and 1.5 GB of memory. The algorithm is implemented as the Ped-GWAS Analysis (Option 29) in the Mendel statistical genetics package, which is freely available for Macintosh, Linux, and Windows platforms from http://genetics.ucla.edu/software/mendel. © 2016 WILEY PERIODICALS, INC.

Prognostic value of echocardiographic indices of left atrial morphology and function in dogs with myxomatous mitral valve disease.

PubMed

Baron Toaldo, Marco; Romito, Giovanni; Guglielmini, Carlo; Diana, Alessia; Pelle, Nazzareno G; Contiero, Barbara; Cipone, Mario

2018-05-01

The prognostic relevance of left atrial (LA) morphological and functional variables, including those derived from speckle tracking echocardiography (STE), has been little investigated in veterinary medicine. To assess the prognostic value of several echocardiographic variables, with a focus on LA morphological and functional variables in dogs with myxomatous mitral valve disease (MMVD). One-hundred and fifteen dogs of different breeds with MMVD. Prospective cohort study. Conventional morphologic and echo-Doppler variables, LA areas and volumes, and STE-based LA strain analysis were performed in all dogs. A survival analysis was performed to test for the best echocardiographic predictors of cardiac-related death. Most of the tested variables, including all LA STE-derived variables were univariate predictors of cardiac death in Cox proportional hazard analysis. Because of strong correlation between many variables, only left atrium to aorta ratio (LA/Ao > 1.7), mitral valve E wave velocity (MV E vel > 1.3 m/s), LA maximal volume (LAVmax > 3.53 mL/kg), peak atrial longitudinal strain (PALS < 30%), and contraction strain index (CSI per 1% increase) were entered in the univariate analysis, and all were predictors of cardiac death. However, only the MV E vel (hazard ratio [HR], 4.45; confidence interval [CI], 1.76-11.24; P < .001) and LAVmax (HR, 2.32; CI, 1.10-4.89; P = .024) remained statistically significant in the multivariable analysis. The assessment of LA dimension and function provides useful prognostic information in dogs with MMVD. Considering all the LA variables, LAVmax appears the strongest predictor of cardiac death, being superior to LA/Ao and STE-derived variables. Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Urine metabolic fingerprinting using LC-MS and GC-MS reveals metabolite changes in prostate cancer: A pilot study.

PubMed

Struck-Lewicka, Wiktoria; Kordalewska, Marta; Bujak, Renata; Yumba Mpanga, Arlette; Markuszewski, Marcin; Jacyna, Julia; Matuszewski, Marcin; Kaliszan, Roman; Markuszewski, Michał J

2015-01-01

Prostate cancer (CaP) is a leading cause of cancer deaths in men worldwide. The alarming statistics, the currently applied biomarkers are still not enough specific and selective. In addition, pathogenesis of CaP development is not totally understood. Therefore, in the present work, metabolomics study related to urinary metabolic fingerprinting analyses has been performed in order to scrutinize potential biomarkers that could help in explaining the pathomechanism of the disease and be potentially useful in its diagnosis and prognosis. Urine samples from CaP patients and healthy volunteers were analyzed with the use of high performance liquid chromatography coupled with time of flight mass spectrometry detection (HPLC-TOF/MS) in positive and negative polarity as well as gas chromatography hyphenated with triple quadruple mass spectrometry detection (GC-QqQ/MS) in a scan mode. The obtained data sets were statistically analyzed using univariate and multivariate statistical analyses. The Principal Component Analysis (PCA) was used to check systems' stability and possible outliers, whereas Partial Least Squares Discriminant Analysis (PLS-DA) was performed for evaluation of quality of the model as well as its predictive ability using statistically significant metabolites. The subsequent identification of selected metabolites using NIST library and commonly available databases allows for creation of a list of putative biomarkers and related biochemical pathways they are involved in. The selected pathways, like urea and tricarboxylic acid cycle, amino acid and purine metabolism, can play crucial role in pathogenesis of prostate cancer disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Simulating Univariate and Multivariate Burr Type IIII and Type XII Distributions through the Method of L-Moments

ERIC Educational Resources Information Center

Pant, Mohan Dev

2011-01-01

The Burr families (Type III and Type XII) of distributions are traditionally used in the context of statistical modeling and for simulating non-normal distributions with moment-based parameters (e.g., Skew and Kurtosis). In educational and psychological studies, the Burr families of distributions can be used to simulate extremely asymmetrical and…

Workplace stress in nursing workers from an emergency hospital: Job Stress Scale analysis.

PubMed

Urbanetto, Janete de Souza; da Silva, Priscila Costa; Hoffmeister, Eveline; de Negri, Bianca Souza; da Costa, Bartira Ercília Pinheiro; Poli de Figueiredo, Carlos Eduardo

2011-01-01

This study identifies workplace stress according to the Job Stress Scale and associates it with socio-demographic and occupational variables of nursing workers from an emergency hospital. This is a cross-sectional study and data were collected through a questionnaire applied to 388 nursing professionals. Descriptive statistics were applied; univariate and multivariate analyses were performed. The results indicate there is a significant association with being a nursing technician or auxiliary, working in the position for more than 15 years, and having low social support, with 3.84, 2.25 and 4.79 times more chances of being placed in the 'high strain job' quadrant. The study reveals that aspects related to the workplace should be monitored by competent agencies in order to improve the quality of life of nursing workers.

Untargeted metabolomics analysis reveals dynamic changes in azelaic acid- and salicylic acid derivatives in LPS-treated Nicotiana tabacum cells.

PubMed

Mhlongo, M I; Tugizimana, F; Piater, L A; Steenkamp, P A; Madala, N E; Dubery, I A

2017-01-22

To counteract biotic stress factors, plants employ multilayered defense mechanisms responsive to pathogen-derived elicitor molecules, and regulated by different phytohormones and signaling molecules. Here, lipopolysaccharide (LPS), a microbe-associated molecular pattern (MAMP) molecule, was used to induce defense responses in Nicotiana tabacum cell suspensions. Intracellular metabolites were extracted with methanol and analyzed using a liquid chromatography-mass spectrometry (UHPLC-qTOF-MS/MS) platform. The generated data were processed and examined with multivariate and univariate statistical tools. The results show time-dependent dynamic changes and accumulation of glycosylated signaling molecules, specifically those of azelaic acid, salicylic acid and methyl-salicylate as contributors to the altered metabolomic state in LPS-treated cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Ulex europeus agglutinin-I binding as a potential prognostic marker in ovarian cancer.

PubMed

Blonski, Katharina; Milde-Langosch, Karin; Bamberger, Ana-Maria; Osterholz, Tina; Utler, Christian; Berger, Jürgen; Löning, Thomas; Schumacher, Udo

2007-01-01

Ovarian cancer represents the malignant tumour of the female genital tract with the worst prognosis, mainly caused by early intraperitoneal spread. Cell-to-cell and cell-to-matrix interactions play a functionally important role in this spread and are both mediated by the cell membrane. Changes in the glycosylation of the cell membrane, as detected by lectin histochemistry, are sometimes associated with a poor prognosis. The expression of lectin binding of 164 ovarian cancer patients was analysed and the staining results were correlated with the clinical data of the patients. The univariate and multivariate statistical analysis revealed an independent prognostic significance for Ulex europeus agglutinin-I (UEA-I) binding. These findings indicate that UEA-I binding can serve as a prognostic factor in ovarian cancer.

Down regulation of E-Cadherin (ECAD) - a predictor for occult metastatic disease in sentinel node biopsy of early squamous cell carcinomas of the oral cavity and oropharynx

PubMed Central

2011-01-01

Background Prognostic factors in predicting occult lymph node metastasis in patients with head and neck squamous-cell carcinoma (HNSCC) are necessary to improve the results of the sentinel lymph node procedure in this tumour type. The E-Cadherin glycoprotein is an intercellular adhesion molecule in epithelial cells, which plays an important role in establishing and maintaining intercellular connections. Objectives To determine the value of the molecular marker E-Cadherin in predicting regional metastatic disease. Methods E-Cadherin expression in tumour tissue of 120 patients with HNSCC of the oral cavity and oropharynx were evaluated using the tissue microarray technique. 110 tumours were located in the oral cavity (91.7%; mostly tongue), 10 tumours in the oropharynx (8.3%). Intensity of E-Cadherin expression was quantified by the Intensity Reactivity Score (IRS). These results were correlated with the lymph node status of biopsied sentinel lymph nodes. Univariate and multivariate analysis was used to determine statistical significance. Results pT-stage, gender, tumour side and location did not correlate with lymph node metastasis. Differentiation grade (p = 0.018) and down regulation of E-Cadherin expression significantly correlate with positive lymph node status (p = 0.005) in univariate and multivariate analysis. Conclusion These data suggest that loss of E-cadherin expression is associated with increased lymhogeneous metastasis of HNSCC. E-cadherin immunohistochemistry may be used as a predictor for lymph node metastasis in squamous cell carcinoma of the oral cavity and oropharynx. Level of evidence: 2b PMID:21639893

The effect of kidney morcellation on operative time, incision complications, and postoperative analgesia after laparoscopic nephrectomy.

PubMed

Camargo, Affonso H; Rubenstein, Jonathan N; Ershoff, Brent D; Meng, Maxwell V; Kane, Christopher J; Stoller, Marshall L

2006-01-01

Compare the outcomes between kidney morcellation and two types of open specimen extraction incisions, several covariates need to be taken into consideration that have not yet been studied. We retrospectively reviewed 153 consecutive patients who underwent laparoscopic nephrectomy at our institution, 107 who underwent specimen morcellation and 46 with intact specimen removal, either those with connected port sites with a muscle-cutting incision and those with a remote, muscle-splitting incision. Operative time, postoperative analgesia requirements, and incisional complications were evaluated using univariate and multivariate analysis, comparing variables such as patient age, gender, body mass index (BMI), laterality, benign versus cancerous renal conditions, estimated blood loss, specimen weight, overall complications, and length of stay. There was no significant difference for operative time between the 2 treatment groups (p = 0.65). Incision related complications occurred in 2 patients (4.4%) from the intact specimen group but none in the morcellation group (p = 0.03). Overall narcotic requirement was lower in patients with morcellated (41 mg) compared to intact specimen retrieval (66 mg) on univariate (p = 0.03) and multivariate analysis (p = 0.049). Upon further stratification, however, there was no significant difference in mean narcotic requirement between the morcellation and muscle-splitting incision subgroup (p = 0.14). Morcellation does not extend operative time, and is associated with significantly less postoperative pain compared to intact specimen retrieval overall, although this is not statistically significant if a remote, muscle-splitting incision is made. Morcellation markedly reduces the risk of incisional-related complications.

Impaired health status, sleep disorders, and pain in the craniomandibular and cervical spinal regions.

PubMed

Lobbezoo, Frank; Visscher, Corine M; Naeije, Machiel

2004-02-01

This study investigated the relationship between health status (i.e., physical well-being and quality of life), sleep disorders (e.g., insomnia, sleep-related depression and anxiety), and musculoskeletal pain in the craniomandibular and cervical spinal regions. The number of painful body areas below the cervical spine (i.e., widespread pain) was also taken into account. Two questionnaires, viz., the RAND 36-item Health Survey Questionnaire and the Dutch Sleep Disorders Questionnaire (SDQ), were administered to 103 persons who could unequivocally be classified into one of four mutually exclusive groups: No pain, craniomandibular pain (CMP), cervical spinal pain (CSP), and both CMP and CSP. Body drawings were used for the self-report of widespread pain. Multivariate analysis of variance showed effects of gender, group, and widespread pain on the questionnaire scales; not of age. As shown by univariate analysis of variance, men suffered more from sleep apnea than did women. No other gender differences were found. Simple contrast analyses following univariate analyses of the group and widespread pain effects showed that, in general, more questionnaire scales, both of the RAND-36 and of the SDQ, reached statistical significance with an increase in the number of painful areas. It was concluded that both musculoskeletal pain in the trigemino-cervical area and widespread body pain are associated with an increased impairment of health status. Also, sleep disorders are frequently found in patients with chronic pain in the craniomandibular and cervical spinal regions as well as in patients with widespread pain. The more painful areas there are, the likelier it is that sleep disorders are present.

Continuous Aspirin Use Does Not Increase Bleeding Risk of Split-Thickness Skin Transplantation Repair to Chronic Wounds.

PubMed

Sun, Yanwei; Wang, Yibing; Li, Liang; Zhang, Zheng; Wang, Ning; Wu, Dan

Discontinuation of aspirin therapy before cutaneous surgery may cause serious complications. The aim of this prospective study was to evaluate the bleeding risk of split-thickness skin transplantation repair to chronic wounds in patients on aspirin therapy. A total of 97 patients who underwent split-thickness skin transplantation surgery of chronic wounds during a 2-year period were enrolled. They were categorized on the basis of aspirin therapies. The primary outcome was postoperative bleeding and bleeding complications. Univariate analysis was performed to examine the association between aspirin and bleeding complications. Among the 26 patients taking aspirin continuously in group A, there were 5 bleeding complications (19.23%). Among the 55 nonusers in group B, there were 10 bleeding complications (18.18%). Among the 16 discontinuous patients in group C, there were 3 bleeding complications (18.75%). No statistical differences were found among the groups ( P = .956). Univariate analysis showed that continuous aspirin use was not significantly associated with bleeding complications (odds ratio, 0.933; 95% confidence interval, 0.283-3.074; P = .910 in the aspirin and control groups) and that discontinuous aspirin use was not significantly associated with bleeding complications (odds ratio, 0.963; 95% confidence interval, 0.230-4.025; P = .959 in the aspirin and control groups; odds ratio, 0.969; 95% confidence interval, 0.198-4.752; P = .969 in the aspirin and discontinuous groups). Continuous aspirin use does not produce an additional bleeding risk in patients who undergo split-thickness skin transplantation repair of chronic wounds.

Toward the improvement in fetal monitoring during labor with the inclusion of maternal heart rate analysis.

PubMed

Gonçalves, Hernâni; Pinto, Paula; Silva, Manuela; Ayres-de-Campos, Diogo; Bernardes, João

2016-04-01

Fetal heart rate (FHR) monitoring is used routinely in labor, but conventional methods have a limited capacity to detect fetal hypoxia/acidosis. An exploratory study was performed on the simultaneous assessment of maternal heart rate (MHR) and FHR variability, to evaluate their evolution during labor and their capacity to detect newborn acidemia. MHR and FHR were simultaneously recorded in 51 singleton term pregnancies during the last two hours of labor and compared with newborn umbilical artery blood (UAB) pH. Linear/nonlinear indices were computed separately for MHR and FHR. Interaction between MHR and FHR was quantified through the same indices on FHR-MHR and through their correlation and cross-entropy. Univariate and bivariate statistical analysis included nonparametric confidence intervals and statistical tests, receiver operating characteristic curves and linear discriminant analysis. Progression of labor was associated with a significant increase in most MHR and FHR linear indices, whereas entropy indices decreased. FHR alone and in combination with MHR as FHR-MHR evidenced the highest auROC values for prediction of fetal acidemia, with 0.76 and 0.88 for the UAB pH thresholds 7.20 and 7.15, respectively. The inclusion of MHR on bivariate analysis achieved sensitivity and specificity values of nearly 100 and 89.1%, respectively. These results suggest that simultaneous analysis of MHR and FHR may improve the identification of fetal acidemia compared with FHR alone, namely during the last hour of labor.

Compounding approach for univariate time series with nonstationary variances

NASA Astrophysics Data System (ADS)

Schäfer, Rudi; Barkhofen, Sonja; Guhr, Thomas; Stöckmann, Hans-Jürgen; Kuhl, Ulrich

2015-12-01

A defining feature of nonstationary systems is the time dependence of their statistical parameters. Measured time series may exhibit Gaussian statistics on short time horizons, due to the central limit theorem. The sample statistics for long time horizons, however, averages over the time-dependent variances. To model the long-term statistical behavior, we compound the local distribution with the distribution of its parameters. Here, we consider two concrete, but diverse, examples of such nonstationary systems: the turbulent air flow of a fan and a time series of foreign exchange rates. Our main focus is to empirically determine the appropriate parameter distribution for the compounding approach. To this end, we extract the relevant time scales by decomposing the time signals into windows and determine the distribution function of the thus obtained local variances.

Compounding approach for univariate time series with nonstationary variances.

PubMed

Schäfer, Rudi; Barkhofen, Sonja; Guhr, Thomas; Stöckmann, Hans-Jürgen; Kuhl, Ulrich

2015-12-01

A defining feature of nonstationary systems is the time dependence of their statistical parameters. Measured time series may exhibit Gaussian statistics on short time horizons, due to the central limit theorem. The sample statistics for long time horizons, however, averages over the time-dependent variances. To model the long-term statistical behavior, we compound the local distribution with the distribution of its parameters. Here, we consider two concrete, but diverse, examples of such nonstationary systems: the turbulent air flow of a fan and a time series of foreign exchange rates. Our main focus is to empirically determine the appropriate parameter distribution for the compounding approach. To this end, we extract the relevant time scales by decomposing the time signals into windows and determine the distribution function of the thus obtained local variances.

Comparison of univariate and multivariate calibration for the determination of micronutrients in pellets of plant materials by laser induced breakdown spectrometry

NASA Astrophysics Data System (ADS)

Braga, Jez Willian Batista; Trevizan, Lilian Cristina; Nunes, Lidiane Cristina; Rufini, Iolanda Aparecida; Santos, Dário, Jr.; Krug, Francisco José

2010-01-01

The application of laser induced breakdown spectrometry (LIBS) aiming the direct analysis of plant materials is a great challenge that still needs efforts for its development and validation. In this way, a series of experimental approaches has been carried out in order to show that LIBS can be used as an alternative method to wet acid digestions based methods for analysis of agricultural and environmental samples. The large amount of information provided by LIBS spectra for these complex samples increases the difficulties for selecting the most appropriated wavelengths for each analyte. Some applications have suggested that improvements in both accuracy and precision can be achieved by the application of multivariate calibration in LIBS data when compared to the univariate regression developed with line emission intensities. In the present work, the performance of univariate and multivariate calibration, based on partial least squares regression (PLSR), was compared for analysis of pellets of plant materials made from an appropriate mixture of cryogenically ground samples with cellulose as the binding agent. The development of a specific PLSR model for each analyte and the selection of spectral regions containing only lines of the analyte of interest were the best conditions for the analysis. In this particular application, these models showed a similar performance, but PLSR seemed to be more robust due to a lower occurrence of outliers in comparison to the univariate method. Data suggests that efforts dealing with sample presentation and fitness of standards for LIBS analysis must be done in order to fulfill the boundary conditions for matrix independent development and validation.

Is there an association between flow diverter fish mouthing and delayed-type hypersensitivity to metals?-a case-control study.

PubMed

Kocer, Naci; Mondel, Prabath Kumar; Yamac, Elif; Kavak, Ayse; Kizilkilic, Osman; Islak, Civan

2017-11-01

Flow diverters are increasingly used in the treatment of complex and giant intracranial aneurysms. However, they are associated with complications like late aneurysmal rupture. Additionally, flow diverters show focal structural decrease in luminal diameter without any intimal hyperplasia. This resembles a "fish mouth" when viewed en face. In this pilot study, we tested the hypothesis of a possible association between flow diverter fish-mouthing and delayed-type hypersensitivity to its metal constituents. We retrospectively reviewed patient records from our center between May 2010 and November 2015. A total of nine patients had flow diverter fish mouthing. A control group of 25 patients was selected. All study participants underwent prospective patch test to detect hypersensitivity to flow diverter metal constituents. Analysis was performed using logistic regression analysis and Wilcoxon sign rank sum test. Univariate and multivariate analyses were performed to test variables to predict flow diverter fish mouthing. The association between flow diverter fish mouthing and positive patch test was not statistically significant. In multivariate analysis, history of allergy and maximum aneurysm size category was associated with flow diverter fish mouthing. This was further confirmed on Wilcoxon sign rank sum test. The study showed statistically significant association between flow diverter fish mouthing and history of contact allergy and a small aneurysmal size. Further large-scale studies are needed to detect a statistically significant association between flow diverter fish mouthing and patch test. We recommend early and more frequent follow-up imaging in patients with contact allergy to detect flow diverter fish mouthing and its subsequent evolution.

Flood risk analysis for flood control and sediment transportation: a case study in the catchments of the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Wang, Y.; Chang, J.; Guo, A.

2017-12-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on flood control systems. Given this focus, a univariate and copula-based bivariate hydrological risk framework focusing on flood control and sediment transport is proposed in the current work. Additionally, the conditional probabilities of occurrence of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula model. Moreover, a Monte Carlo-based algorithm is used to evaluate the uncertainties of univariate and bivariate hydrological risk. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The results indicate that (1) 2-day and 3-day consecutive rainfall are highly correlated with the annual maximum flood discharge (AMF) in UCX and UCH, respectively; and (2) univariate and bivariate return periods, risk and reliability for the purposes of flood control and sediment transport are successfully estimated. Sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the AMF, exceeding the design flood of downstream hydraulic structures in the UCX and UCH. Most importantly, there was considerable sampling uncertainty in the univariate and bivariate hydrologic risk analysis, which would greatly challenge measures of future flood mitigation. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

A retrospective analysis of the role of proton pump inhibitors in colorectal cancer disease survival

PubMed Central

Graham, C.; Orr, C.; Bricks, C.S.; Hopman, W.M.; Hammad, N.; Ramjeesingh, R.

2016-01-01

Background Proton pump inhibitors (ppis) are a commonly used medication. A limited number of studies have identified a weak-to-moderate association between ppi use and colorectal cancer (crc) risk, but none to date have identified an effect of ppi use on crc survival. We therefore postulated that an association between ppi use and crc survival might potentially exist. Methods We performed a retrospective chart review of 1304 crc patients diagnosed from January 2005 to December 2011 and treated at the Cancer Centre of Southeastern Ontario. Kaplan–Meier analysis and Cox proportional hazards regression models were used to evaluate overall survival (os). Results We identified 117 patients (9.0%) who were taking ppis at the time of oncology consult. Those taking a ppi were also more often taking asa or statins (or both) and had a statistically significantly increased rate of cardiac disease. No identifiable difference in tumour characteristics was evident in the two groups, including tumour location, differentiation, lymph node status, and stage. Univariate analysis identified a statistically nonsignificant difference in survival, with those taking a ppi experiencing lesser 1-year (82.1% vs. 86.7%, p = 0.161), 2-year (70.1% vs. 76.8%, p = 0.111), and 5-year os (55.2% vs. 62.9%, p = 0.165). When controlling for patient demographics and tumour characteristics, multivariate Cox regression analysis identified a statistically significant effect of ppi in our patient population (hazard ratio: 1.343; 95% confidence interval: 1.011 to 1.785; p = 0.042). Conclusions Our results suggest a potential adverse effect of ppi use on os in crc patients. These results need further evaluation in prospective analyses. PMID:28050148

Use of Multivariate Linkage Analysis for Dissection of a Complex Cognitive Trait

PubMed Central

Marlow, Angela J.; Fisher, Simon E.; Francks, Clyde; MacPhie, I. Laurence; Cherny, Stacey S.; Richardson, Alex J.; Talcott, Joel B.; Stein, John F.; Monaco, Anthony P.; Cardon, Lon R.

2003-01-01

Replication of linkage results for complex traits has been exceedingly difficult, owing in part to the inability to measure the precise underlying phenotype, small sample sizes, genetic heterogeneity, and statistical methods employed in analysis. Often, in any particular study, multiple correlated traits have been collected, yet these have been analyzed independently or, at most, in bivariate analyses. Theoretical arguments suggest that full multivariate analysis of all available traits should offer more power to detect linkage; however, this has not yet been evaluated on a genomewide scale. Here, we conduct multivariate genomewide analyses of quantitative-trait loci that influence reading- and language-related measures in families affected with developmental dyslexia. The results of these analyses are substantially clearer than those of previous univariate analyses of the same data set, helping to resolve a number of key issues. These outcomes highlight the relevance of multivariate analysis for complex disorders for dissection of linkage results in correlated traits. The approach employed here may aid positional cloning of susceptibility genes in a wide spectrum of complex traits. PMID:12587094

A preliminary analysis of quantifying computer security vulnerability data in "the wild"

NASA Astrophysics Data System (ADS)

Farris, Katheryn A.; McNamara, Sean R.; Goldstein, Adam; Cybenko, George

2016-05-01

A system of computers, networks and software has some level of vulnerability exposure that puts it at risk to criminal hackers. Presently, most vulnerability research uses data from software vendors, and the National Vulnerability Database (NVD). We propose an alternative path forward through grounding our analysis in data from the operational information security community, i.e. vulnerability data from "the wild". In this paper, we propose a vulnerability data parsing algorithm and an in-depth univariate and multivariate analysis of the vulnerability arrival and deletion process (also referred to as the vulnerability birth-death process). We find that vulnerability arrivals are best characterized by the log-normal distribution and vulnerability deletions are best characterized by the exponential distribution. These distributions can serve as prior probabilities for future Bayesian analysis. We also find that over 22% of the deleted vulnerability data have a rate of zero, and that the arrival vulnerability data is always greater than zero. Finally, we quantify and visualize the dependencies between vulnerability arrivals and deletions through a bivariate scatterplot and statistical observations.

Comparison between the univariate and multivariate analysis on the partial characterization of the endoglucanase produced in the solid state fermentation by Aspergillus oryzae ATCC 10124.

PubMed

de Brito, Aila Riany; Santos Reis, Nadabe Dos; Silva, Tatielle Pereira; Ferreira Bonomo, Renata Cristina; Trovatti Uetanabaro, Ana Paula; de Assis, Sandra Aparecida; da Silva, Erik Galvão Paranhos; Aguiar-Oliveira, Elizama; Oliveira, Julieta Rangel; Franco, Marcelo

2017-11-26

Endoglucanase production by Aspergillus oryzae ATCC 10124 cultivated in rice husks or peanut shells was optimized by experimental design as a function of humidity, time, and temperature. The optimum temperature for the endoglucanase activity was estimated by a univariate analysis (one factor at the time) as 50°C (rice husks) and 60°C (peanut shells), however, by a multivariate analysis (synergism of factors), it was determined a different temperature (56°C) for endoglucanase from peanut shells. For the optimum pH, values determined by univariate and multivariate analysis were 5 and 5.2 (rice husk) and 5 and 7.6 (peanut shells). In addition, the best half-lives were observed at 50°C as 22.8 hr (rice husks) and 7.3 hr (peanut shells), also, 80% of residual activities was obtained between 30 and 50°C for both substrates, and the pH stability was improved at 5-7 (rice hulls) and 6-9 (peanut shells). Both endoglucanases obtained presented different characteristics as a result of the versatility of fungi in different substrates.

Risk factors for incidental durotomy during lumbar surgery: a retrospective study by multivariate analysis.

PubMed

Chen, Zhixiang; Shao, Peng; Sun, Qizhao; Zhao, Dong

2015-03-01

The purpose of the present study was to use a prospectively collected data to evaluate the rate of incidental durotomy (ID) during lumbar surgery and determine the associated risk factors by using univariate and multivariate analysis. We retrospectively reviewed 2184 patients who underwent lumbar surgery from January 1, 2009 to December 31, 2011 at a single hospital. Patients with ID (n=97) were compared with the patients without ID (n=2019). The influences of several potential risk factors that might affect the occurrence of ID were assessed using univariate and multivariate analyses. The overall incidence of ID was 4.62%. Univariate analysis demonstrated that older age, diabetes, lumbar central stenosis, posterior approach, revision surgery, prior lumber surgery and minimal invasive surgery are risk factors for ID during lumbar surgery. However, multivariate analysis identified older age, prior lumber surgery, revision surgery, and minimally invasive surgery as independent risk factors. Older age, prior lumber surgery, revision surgery, and minimal invasive surgery were independent risk factors for ID during lumbar surgery. These findings may guide clinicians making future surgical decisions regarding ID and aid in the patient counseling process to alleviate risks and complications. Copyright © 2015 Elsevier B.V. All rights reserved.

Gender differences in health-related quality of life of adolescents with cystic fibrosis

PubMed Central

Arrington-Sanders, Renata; Yi, Michael S; Tsevat, Joel; Wilmott, Robert W; Mrus, Joseph M; Britto, Maria T

2006-01-01

Background Female patients with cystic fibrosis (CF) have consistently poorer survival rates than males across all ages. To determine if gender differences exist in health-related quality of life (HRQOL) of adolescent patients with CF, we performed a cross-section analysis of CF patients recruited from 2 medical centers in 2 cities during 1997–2001. Methods We used the 87-item child self-report form of the Child Health Questionnaire to measure 12 health domains. Data was also collected on age and forced expiratory volume in 1 second (FEV1). We analyzed data from 98 subjects and performed univariate analyses and linear regression or ordinal logistic regression for multivariable analyses. Results The mean (SD) age was 14.6 (2.5) years; 50 (51.0%) were female; and mean FEV1 was 71.6% (25.6%) of predicted. There were no statistically significant gender differences in age or FEV1. In univariate analyses, females reported significantly poorer HRQOL in 5 of the 12 domains. In multivariable analyses controlling for FEV1 and age, we found that female gender was associated with significantly lower global health (p < 0.05), mental health (p < 0.01), and general health perceptions (p < 0.05) scores. Conclusion Further research will need to focus on the causes of these differences in HRQOL and on potential interventions to improve HRQOL of adolescent patients with CF. PMID:16433917

The impact of teacher preparation on student achievement in rural secondary schools

NASA Astrophysics Data System (ADS)

Barnes, Shontier Prescott

The primary purpose of this study was to examine significant differences, if any, in student achievement in the area of math and science of students taught by traditionally certified teachers and alternatively certified teachers. This study examined alternatively certified teachers, as identified from through the Georgia TAPP (Teacher Alternative Preparation Program), and traditionally certified teachers in rural high schools in the Central Savannah River Area of Georgia. Student achievement was measured by student scores on the Algebra I and Physical Science End-Of-Course Test, a criterion-referenced test aligned with state adopted curriculum standards. The study utilized frequency distributions, correlations, descriptive statistics, and univariate analysis of variance (ANOVA) to examine the data. Univariate tests were done to find individual differences for each dependent variable. The ANOVA was used for the single dependent (student achievement) and formed comparisons and tracked the effect of the independent variable (teacher preparation), each of which (traditional and alternative) may have a number of levels and may interact to affect the dependent variable. The covariates, the independent variables not manipulated, but still affecting the response, are students' ethnicity, gender, and school socioeconomic status were also analyzed to predict student achievement. KEY WORDS. Teacher Preparation, Student Achievement, Math, Science, Traditionally certified teachers, Alternatively certified teachers, Georgia TAPP (Teacher Alternative Preparation Program), End-Of-Course Test (EOCT), Performance standard.

Intimate partner violence in Madrid: a time series analysis (2008-2016).

PubMed

Sanz-Barbero, Belén; Linares, Cristina; Vives-Cases, Carmen; González, José Luis; López-Ossorio, Juan José; Díaz, Julio

2018-06-02

This study analyzes whether there are time patterns in different intimate partner violence (IPV) indicators and aims to obtain models that can predict the behavior of these time series. Univariate autoregressive moving average models were used to analyze the time series corresponding to the number of daily calls to the 016 telephone IPV helpline and the number of daily police reports filed in the Community of Madrid during the period 2008-2015. Predictions were made for both dependent variables for 2016. The daily number of calls to the 016 telephone IPV helpline decreased during January 2008-April 2012 and increased during April 2012-December 2015. No statistically significant change was observed in the trend of the number of daily IPV police reports. The number of IPV police reports filed increased on weekends and on Christmas holidays. The number of calls to the 016 IPV help line increased on Mondays. Using data from 2008 to 2015, the univariate autoregressive moving average models predicted 64.2% of calls to the 016 telephone IPV helpline and 73.2% of police reports filed during 2016 in the Community of Madrid. Our results suggest the need for an increase in police and judicial resources on nonwork days. Also, the 016 telephone IPV helpline should be especially active on work days. Copyright © 2018 Elsevier Inc. All rights reserved.

Modifiable Lifestyle Behaviors Are Associated With Metabolic Syndrome in a Taiwanese Population.

PubMed

Lin, Kuei-Man; Chiou, Jeng-Yuan; Ko, Shu-Hua; Tan, Jung-Ying; Huang, Chien-Ning; Liao, Wen-Chun

2015-11-01

To explore associations between metabolic syndrome and modifiable lifestyle behaviors among the adult population in Taiwan. This cross-sectional study analyzed data from a nationally representative sample that participated in the 2005-2008 Nutrition and Health Survey in Taiwan. The sample (2,337 participants older than 19 years) provided data on demographic characteristics, modifiable lifestyle behaviors, anthropometric measurements, and blood chemistry panel. These data were analyzed by descriptive statistics, univariate logistic regression, and multivariate logistic regression to determine factors associated with metabolic syndrome. Metabolic syndrome had a prevalence of 25.2%, and this prevalence increased with age. In univariate regression analysis, metabolic syndrome was associated with age, living with family members, educational level, and modifiable lifestyle behaviors (smoking, drinking, betel quid chewing, and physical activity). Individuals with a smoking history and currently chewing betel quid had the highest risk for metabolic syndrome. The risk for metabolic syndrome might be reduced by public health campaigns to encourage people to quit smoking cigarettes and chewing betel quid. Implementing more modifiable lifestyle behaviors in daily life will decrease metabolic syndrome in Taiwan. Considering that betel quid chewing and tobacco smoking interact to adversely affect metabolic syndrome risk, public health campaigns against both behaviors seem to be a cost-effective and efficient health promotion strategy to reduce the prevalence rate of metabolic syndrome. © 2015 Sigma Theta Tau International.

VEGF and Ki-67 Overexpression in Predicting Poor Overall Survival in Adenoid Cystic Carcinoma.

PubMed

Park, Seongyeol; Nam, Soo Jeong; Keam, Bhumsuk; Kim, Tae Min; Jeon, Yoon Kyung; Lee, Se-Hoon; Hah, J Hun; Kwon, Tack-Kyun; Kim, Dong-Wan; Sung, Myung-Whun; Heo, Dae Seog; Bang, Yung-Jue

2016-04-01

The purpose of this study was to evaluate potential prognostic factors in patients with adenoid cystic carcinoma (ACC). A total of 68 patients who underwent curative surgery and had available tissue were enrolled in this study. Their medical records and pathologic slides were reviewed and immunohistochemistry for basic fibroblast growth factor, fibroblast growth factor receptor (FGFR) 2, FGFR3, c-kit, Myb proto-oncogene protein, platelet-derived growth factor receptor beta, vascular endothelial growth factor (VEGF), and Ki-67 was performed. Univariate and multivariate analysis was performed for determination of disease-free survival (DFS) and overall survival (OS). In univariate analyses, primary site of nasal cavity and paranasal sinus (p=0.022) and Ki-67 expression of more than 7% (p=0.001) were statistically significant factors for poor DFS. Regarding OS, perineural invasion (p=0.032), high expression of VEGF (p=0.033), and high expression of Ki-67 (p=0.007) were poor prognostic factors. In multivariate analyses, primary site of nasal cavity and paranasal sinus (p=0.028) and high expression of Ki-67 (p=0.004) were independent risk factors for poor DFS, and high expression of VEGF (p=0.011) and Ki-67 (p=0.011) showed independent association with poor OS. High expression of VEGF and Ki-67 were independent poor prognostic factors for OS in ACC.

Association factor analysis between osteoporosis with cerebral artery disease: The STROBE study.

PubMed

Jin, Eun-Sun; Jeong, Je Hoon; Lee, Bora; Im, Soo Bin

2017-03-01

The purpose of this study was to determine the clinical association factors between osteoporosis and cerebral artery disease in Korean population. Two hundred nineteen postmenopausal women and men undergoing cerebral computed tomography angiography were enrolled in this study to evaluate the cerebral artery disease by cross-sectional study. Cerebral artery disease was diagnosed if there was narrowing of 50% higher diameter in one or more cerebral vessel artery or presence of vascular calcification. History of osteoporotic fracture was assessed using medical record, and radiographic data such as simple radiography, MRI, and bone scan. Bone mineral density was checked by dual-energy x-ray absorptiometry. We reviewed clinical characteristics in all patients and also performed subgroup analysis for total or extracranial/ intracranial cerebral artery disease group retrospectively. We performed statistical analysis by means of chi-square test or Fisher's exact test for categorical variables and Student's t-test or Wilcoxon's rank sum test for continuous variables. We also used univariate and multivariate logistic regression analyses were conducted to assess the factors associated with the prevalence of cerebral artery disease. A two-tailed p-value of less than 0.05 was considered as statistically significant. All statistical analyses were performed using R (version 3.1.3; The R Foundation for Statistical Computing, Vienna, Austria) and SPSS (version 14.0; SPSS, Inc, Chicago, Ill, USA). Of the 219 patients, 142 had cerebral artery disease. All vertebral fracture was observed in 29 (13.24%) patients. There was significant difference in hip fracture according to the presence or absence of cerebral artery disease. In logistic regression analysis, osteoporotic hip fracture was significantly associated with extracranial cerebral artery disease after adjusting for multiple risk factors. Females with osteoporotic hip fracture were associated with total calcified cerebral artery disease. Some clinical factors such as age, hypertension, and osteoporotic hip fracture, smoking history and anti-osteoporosis drug use were associated with cerebral artery disease.

Across the Great Divide: The Effects of Technology in Secondary Biology Classrooms

NASA Astrophysics Data System (ADS)

Worley, Johnny Howard, II

This study investigates the relationship between technology use and student achievement in public high school across North Carolina. The purpose of this study was to determine whether a digital divide (differences in technology utilization based on student demographics of race/ethnicity, gender, socioeconomic status, and municipality) exists among schools and whether those differences relate to student achievement in high school biology classrooms. The study uses North Carolina end-of-course (EOC) data for biology to analyze student demographic data and assessment results from the 2010-2011 school year from the North Carolina Department of Public Instruction. The data analyses use descriptive and factorial univariate statistics to determine the existence of digital divides and their effects on biology achievement. Analysis of these data described patterns of technology use to determine whether potential variances resulted in a digital divide. Specific technology uses were identified in the data and then their impact on biology achievement scores within various demographic groups was examined. Research findings revealed statistically significant variations of use within different population groups. Despite being statistically significant, the relevance of the association in the variations was minimal at best -- based on the effect scale established by Cohen (1988). Additional factorial univariate analyses were employed to determine potential relationships between technology use and student achievement. The data revealed that technology use did not influence the variation of student achievement scale scores as much as race/ethnicity and socioeconomic status. White students outperformed Hispanic students by an average of three scale score points and Black students by an average of six scale score points. Technology use alone averaged less than a one point difference in mean scale scores, and only when interacting with race, gender, and/or SES did the mean difference increase. However, this increase within the context of the biology scale score range was negligible. This study contributes to the existing body of research on the effects of technology use on student achievement and its influence within various student demographic groups and municipalities. The study also provides additional research information for effective technology utilization, implementation, and instruction in educational environments.

Nonstationary frequency analysis for the trivariate flood series of the Weihe River

NASA Astrophysics Data System (ADS)

Jiang, Cong; Xiong, Lihua

2016-04-01

Some intensive human activities such as water-soil conservation can significantly alter the natural hydrological processes of rivers. In this study, the effect of the water-soil conservation on the trivariate flood series from the Weihe River located in the Northwest China is investigated. The annual maxima daily discharge, annual maxima 3-day flood volume and annual maxima 5-day flood volume are chosen as the study data and used to compose the trivariate flood series. The nonstationarities in both the individual univariate flood series and the corresponding antecedent precipitation series generating the flood events are examined by the Mann-Kendall trend test. It is found that all individual univariate flood series present significant decreasing trend, while the antecedent precipitation series can be treated as stationary. It indicates that the increase of the water-soil conservation land area has altered the rainfall-runoff relationship of the Weihe basin, and induced the nonstationarities in the three individual univariate flood series. The time-varying moments model based on the Pearson type III distribution is applied to capture the nonstationarities in the flood frequency distribution with the water-soil conservation land area introduced as the explanatory variable of the flood distribution parameters. Based on the analysis for each individual univariate flood series, the dependence structure among the three univariate flood series are investigated by the time-varying copula model also with the water-soil conservation land area as the explanatory variable of copula parameters. The results indicate that the dependence among the trivariate flood series is enhanced by the increase of water-soil conservation land area.

Linkage Analysis of a Model Quantitative Trait in Humans: Finger Ridge Count Shows Significant Multivariate Linkage to 5q14.1

PubMed Central

Medland, Sarah E; Loesch, Danuta Z; Mdzewski, Bogdan; Zhu, Gu; Montgomery, Grant W; Martin, Nicholas G

2007-01-01

The finger ridge count (a measure of pattern size) is one of the most heritable complex traits studied in humans and has been considered a model human polygenic trait in quantitative genetic analysis. Here, we report the results of the first genome-wide linkage scan for finger ridge count in a sample of 2,114 offspring from 922 nuclear families. Both univariate linkage to the absolute ridge count (a sum of all the ridge counts on all ten fingers), and multivariate linkage analyses of the counts on individual fingers, were conducted. The multivariate analyses yielded significant linkage to 5q14.1 (Logarithm of odds [LOD] = 3.34, pointwise-empirical p-value = 0.00025) that was predominantly driven by linkage to the ring, index, and middle fingers. The strongest univariate linkage was to 1q42.2 (LOD = 2.04, point-wise p-value = 0.002, genome-wide p-value = 0.29). In summary, the combination of univariate and multivariate results was more informative than simple univariate analyses alone. Patterns of quantitative trait loci factor loadings consistent with developmental fields were observed, and the simple pleiotropic model underlying the absolute ridge count was not sufficient to characterize the interrelationships between the ridge counts of individual fingers. PMID:17907812

Risk models for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP): smoking and chronic liver disease are predictors of protection against PEP.

PubMed

DiMagno, Matthew J; Spaete, Joshua P; Ballard, Darren D; Wamsteker, Erik-Jan; Saini, Sameer D

2013-08-01

We investigated which variables independently associated with protection against or development of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) and severity of PEP. Subsequently, we derived predictive risk models for PEP. In a case-control design, 6505 patients had 8264 ERCPs, 211 patients had PEP, and 22 patients had severe PEP. We randomly selected 348 non-PEP controls. We examined 7 established- and 9 investigational variables. In univariate analysis, 7 variables predicted PEP: younger age, female sex, suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate-difficult cannulation (MDC), pancreatic stent placement, and lower Charlson score. Protective variables were current smoking, former drinking, diabetes, and chronic liver disease (CLD, biliary/transplant complications). Multivariate analysis identified seven independent variables for PEP, three protective (current smoking, CLD-biliary, CLD-transplant/hepatectomy complications) and 4 predictive (younger age, suspected SOD, pancreatic sphincterotomy, MDC). Pre- and post-ERCP risk models of 7 variables have a C-statistic of 0.74. Removing age (seventh variable) did not significantly affect the predictive value (C-statistic of 0.73) and reduced model complexity. Severity of PEP did not associate with any variables by multivariate analysis. By using the newly identified protective variables with 3 predictive variables, we derived 2 risk models with a higher predictive value for PEP compared to prior studies.

Videodermoscopy does not enhance diagnosis of scalp contact dermatitis due to topical minoxidil.

PubMed

Tosti, Antonella; Donati, Aline; Vincenzi, Colombina; Fabbrocini, Gabriella

2009-07-01

Videodermoscopy (VD) is a noninvasive diagnostic tool that provides useful information for the differential diagnosis of scalp disorders. The aim of this study was to investigate if dermoscopy may help the clinician in the diagnosis of contact dermatitis of the scalp. We analyzed the dermoscopic images taken from 7 patients with contact dermatitis due to topical minoxidil, 6 patients complaining of intense scalp itching during treatment with topical minoxidil but with negative patch tests and 19 controls. The following dermoscopic patterns described for scalp diseases were evaluated: Vascular patterns (simple loops, twisted loops and arborizing lines), follicular/perifollicular patterns (yellow dots, empty ostia, white dots, peripilar signs), white scales, yellow scales, follicular plugging, hair diameter diversity, honeycomb pattern and short regrowing hairs. Findings were graded from 0-4, according to severity in 20-fold magnifications. Statistical analysis included univariate analysis and Chi-square test by SPSS version 12. There were no statistical differences in the analysis of the vascular patterns and scales between the 3 groups. We were not able to detect dermoscopic features that can help the clinician in distinguishing scalp contact dermatitis due to topical minoxidil from other conditions that cause severe scalp itching. In particular, minoxidil contact dermatitis does not produce increase or alterations in the morphology of the scalp vessels or significant scalp scaling when evaluated with dermoscopy.

Live weight, carcass ultrasound images, and visual scores in Angus cattle under feeding regimes in Brazil.

PubMed

Pinto, Luís Fernando Batista; Tarouco, Jaime Urdapilleta; Pedrosa, Victor Breno; de Farias Jucá, Adriana; Leão, André Gustavo; Moita, Antonia Kécya França

2013-08-01

This study aimed to evaluate visual precocity, muscling, conformation, skeletal, and breed scores; live weights at birth, at 205, and at 550 days of age; and, besides, rib eye area and fat thickness between the 12th and 13th ribs obtained by ultrasound. Those traits were evaluated in 1,645 Angus cattle kept in five feeding conditions as follows: supplemented or non-supplemented, grazing native pasture or grazing cultivated pasture, and feedlot. Descriptive statistics, Pearson's correlations, and principal component analysis were carried out. Gender and feeding conditions were fixed effects, while animal's age and mother's weight at weaning were the covariates analyzed. Gender and feeding conditions were very significant for the studied traits, but visual scores were not influenced by gender. Animal's age and mother's weight at weaning influenced many traits and must be appropriately adjusted in the statistical models. An important correlation between visual scores, live weights, and carcass traits obtained by ultrasound was found, which can be analyzed by univariate procedure. However, the multivariate approach revealed some information that cannot be neglected in order to ensure a more detailed assessment.

Clinical and imaging predictors of management in retained products of conception.

PubMed

Kamaya, Aya; Krishnarao, Priya Menon; Nayak, Nita; Jeffrey, R Brooke; Maturen, Katherine E

2016-12-01

To determine if clinical and ultrasound (US) imaging features help predict management in clinically suspected retained products of conception (RPOC). 334 patients sonographically evaluated for RPOC were included in this IRB-approved retrospective study. Of the 334 patients, 176 had sonographic diagnosis of RPOC and comprised the final study group. Patients were managed expectantly, medically, or surgically in accordance with clinical judgment of treating physicians. Pelvic sonograms were retrospectively reviewed for endometrial stripe thickness and vascularity was graded on a 0-3 scale based on appearance relative to myometrium (Grade 0: no vascularity, Grade 1: minimal vascularity, Grade 2: moderate vascularity, Grade 3: marked vascularity). Clinical and imaging predictors of management were evaluated in univariate and multivariate analysis. Mean patient age was 29.6 years and mean gestational age was 17.4 weeks. Most (74.4%) women presented with vaginal bleeding. 83 patients (47.2%) were treated conservatively with expectant management, 42 (23.8%) were treated medically, and 51 (29.0%) required surgical intervention. Mean endometrial stripe thickness was 21.3 mm. 47 women (26.7%) had vascularity score of 0; 50 (28.4%) had score 1; 52 (29.6%) had score 2; and 27 (15.3%) had score 3. In univariate analysis, serum hemoglobin (Hb) (p < 0.0001), endometrial stripe thickness on US (p < 0.005), presenting symptoms (p = 0.03), and US vascularity score (p < 0.005) were statistically significant predictors of final management. In multivariate logistic regression, serum Hb (OR 0.69, 95% CI 0.55-0.86, p < 0.0009), endometrial stripe thickness (OR 1.08, 95% CI 1.04-1.12, p < 0.0001), and US vascularity score (OR 1.77, 95% CI 1.16-2.70, p < 0.01) were statistically significant predictors of need for surgery. Serum Hb, endometrial stripe thickness, and US vascularity score were significant predictors of clinical management, particularly the need for surgical intervention, in women with clinically suspected RPOC.

Predicting and evaluation the severity in acute pancreatitis using a new modeling built on body mass index and intra-abdominal pressure.

PubMed

Fei, Yang; Gao, Kun; Tu, Jianfeng; Wang, Wei; Zong, Guang-Quan; Li, Wei-Qin

2017-06-03

Acute pancreatitis (AP) keeps as severe medical diagnosis and treatment problem. Early evaluation for severity and risk stratification in patients with AP is very important. Some scoring system such as acute physiology and chronic health evaluation-II (APACHE-II), the computed tomography severity index (CTSI), Ranson's score and the bedside index of severity of AP (BISAP) have been used, nevertheless, there're a few shortcomings in these methods. The aim of this study was to construct a new modeling including intra-abdominal pressure (IAP) and body mass index (BMI) to evaluate the severity in AP. The study comprised of two independent cohorts of patients with AP, one set was used to develop modeling from Jinling hospital in the period between January 2013 and October 2016, 1073 patients were included in it; another set was used to validate modeling from the 81st hospital in the period between January 2012 and December 2016, 326 patients were included in it. The association between risk factors and severity of AP were assessed by univariable analysis; multivariable modeling was explored through stepwise selection regression. The change in IAP and BMI were combined to generate a regression equation as the new modeling. Statistical indexes were used to evaluate the value of the prediction in the new modeling. Univariable analysis confirmed change in IAP and BMI to be significantly associated with severity of AP. The predict sensitivity, specificity, positive predictive value, negative predictive value and accuracy by the new modeling for severity of AP were 77.6%, 82.6%, 71.9%, 87.5% and 74.9% respectively in the developing dataset. There were significant differences between the new modeling and other scoring systems in these parameters (P < 0.05). In addition, a comparison of the area under receiver operating characteristic curves of them showed a statistically significant difference (P < 0.05). The same results could be found in the validating dataset. A new modeling based on IAP and BMI is more likely to predict the severity of AP. Copyright © 2017. Published by Elsevier Inc.

Detection of Equid herpesvirus type 2 and 5 DNA in uterine flushings of mares with reproductive disorders.

PubMed

Marenzoni, Maria Luisa; Sforna, Monica; Stefanetti, Valentina; Casagrande Proietti, Patrizia; Brignone, Luca; Del Sero, Andrea; Falcioni, Fabio; Orvieto, Simona; Tamantini, Cristina; Tiburzi, Alessandra; Valentini, Silvia; Coletti, Mauro; Timoney, Peter J; Passamonti, Fabrizio

2014-12-05

In recent years, there has been increasing evidence of the potential pathogenic significance of equine gammaherpesviruses in the horse. In humans, cattle and mice, gammaherpesviruses have already been associated with uterine infection. The aim of the present study was to investigate the presence of gammaherpesviruses in uterine flushings of mares with reproductive problems and to evaluate if there was a possible statistical association with clinical and laboratory findings in these cases. A total of 80 uterine flushings were collected from 61 mares with different reproductive problems and these were tested for equine herpesviruses (EHV) 1-5 by PCR. In the case of each mare in the study, the age, history of infertility, presence of anatomical defects in the reproductive tract, presence of systemic or local disease at time of sampling, phase in the oestrous cycle, post-partum interval, nature of uterine lavage performed (low versus large volume lavage), cytological and bacteriological examination results from the uterine flushing, and PCR herpesvirus results were recorded. Univariate analysis and multivariable logistic regression models were used to identify possible statistical associations and risk factors. Nine out of 61 mares (14.7%) had EHV-5 DNA in their uterine flushings. Co-infections with EHV-1 and EHV-2 were present in two cases. Of all the variables analyzed, only the cytological examination findings were associated with EHV-5 PCR positive results, both on univariate and multivariable analysis, especially in cases with an inflammation score of 3. It is postulated that presence of EHV-5 infection in the non-pregnant uterus may have a role to play in reproductive dysfunction and have a negative consequence on the pregnant uterus. Additional studies involving both healthy mares and mares with reproductive problems need to be performed, however, to elucidate whatever role equine gammaherpesviruses may play in the reproductive tract. This would be very worthwhile, since reproductive problems can have a significant impact on the equine breeding industry. Gaining a greater understanding of its causes could lead to new approaches for prevention and treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Racial disparity in colorectal cancer: the role of equal treatment.

PubMed

Laryea, Jonathan A; Siegel, Eric; Klimberg, Suzanne

2014-03-01

Racial disparity exists in colorectal cancer outcomes. The reasons for this are multifactorial. The aim of this study was to evaluate the role of equal treatment of blacks and whites in the elimination of racial disparity in colorectal cancer outcomes. A retrospective cohort study of 878 patients with colorectal cancer diagnosed between 1998 and 2008 was done at a University tertiary referral center. Demographic variables including age, sex, and race were abstracted. Tumor-specific variables including American Joint Committee on Cancer stage, anatomic tumor location, vital status, and survival were obtained. Treatment-specific variables including surgery, chemotherapy, radiotherapy, and follow-up were also obtained. Racial differences in these variables were studied and their effect on overall survival was determined by using univariate and multivariate analyses. The findings were then compared with previous data from our institution. University tertiary referral center. The primary outcomes measured were overall survival and cancer-specific mortality. A total of 878 patients met the inclusion criteria, 186 (21.2%) of whom were black. Blacks were significantly younger at diagnosis in comparison with whites, with a median (quartiles) age of 55 years (28-87) compared with 59 years (23-94) (p = 0.0012). Equal proportions of blacks (78.5%) and whites (79.2%) underwent surgery (p = 0.84), similar proportions of blacks (55.4%) and whites (60.8%) received chemotherapy (p = 0.18), and similar proportions of blacks (17.2%) and whites (20.5%) received radiation therapy (p = 0.31). There was no difference in overall survival or cancer-specific mortality between the 2 racial groups. Univariate analysis showed American Joint Committee on Cancer stage and surgery as the only statistically significant factors for overall survival. On multivariate analysis, stage, surgery, and chemotherapy were the only statistically significant factors. Race was not an independent determinant of survival. There were no differences in overall survival and cancer-related mortality between blacks and whites, and this may have resulted from identical treatment. The previously noted disparities in treatment and overall survival at our institution have disappeared.

[Maternal posture and its influence on birthweight].

PubMed

Takito, Monica Yuri; Benício, Maria Helena D'Aquino; Latorre, Maria do Rosário Dias de Oliveira

2005-06-01

To analyze the relationship between maternal posture/physical activity and inadequate birthweight. Prospective cohort study involving 152 pregnant women from a public low-risk antenatal care facility. Three interviews evaluating the frequency of physical activity were administered to each pregnant woman during gestation. Birthweight (inadequate when <3,000 g and adequate when > or =3,000 g) was the dependent variable and the frequency of physical activity the independent variable. Statistical analysis was performed using logistic univariate analysis and multiple regression controlling for schooling, smoking, living with spouse, and baseline nutritional status. The practice of walking for at least 50 minutes during the first period of pregnancy was identified as a protective factor against inadequate birthweight (adjusted OR=0.44; 95% CI: 0.20-0.98). Standing for 2.5 hours or longer during the second semester of pregnancy was associated with increased risk (adjusted OR=3.23; 95% CI: 1.30-7.99). Dose-response relationships were identified for washing clothing by hand and cooking (p-value for linear trend <0.01 and 0.05, respectively). After confounder control, only washing clothing during the second trimester of gestation remained statistically significant. Our results show the importance of medical orientation regarding posture and physical activity during antenatal care, aiming at the reduction of inadequate birthweight.

Safety in ready mixed concrete industry: descriptive analysis of injuries and development of preventive measures

PubMed Central

AKBOĞA, Özge; BARADAN, Selim

2016-01-01

Ready mixed concrete (RMC) industry, one of the barebones of construction sector, has its distinctive occupational safety and health (OSH) risks. Employees experience risks that emerge during the fabrication of concrete, as well as its delivery to the construction site. Statistics show that usage and demand of RMC have been increasing along with the number of producers and workers. Unfortunately, adequate OSH measures to meet this rapid growth are not in place even in top RMC producing countries, such as Turkey. Moreover, lack of statistical data and academic research in this sector exacerbates this problem. This study aims to fill this gap by conducting data mining in Turkish Social Security Institution archives and performing univariate frequency and cross tabulation analysis on 71 incidents that RMC truck drivers were involved. Also, investigations and interviews were conducted in seven RMC plants in Turkey and Netherlands with OSH point of view. Based on the results of this research, problem areas were determined such as; cleaning truck mixer/pump is a hazardous activity where operators get injured frequently, and struck by falling objects is a major hazard at RMC industry. Finally, Job Safety Analyses were performed on these areas to suggest mitigation methods. PMID:27524105

A power analysis for multivariate tests of temporal trend in species composition.

PubMed

Irvine, Kathryn M; Dinger, Eric C; Sarr, Daniel

2011-10-01

Long-term monitoring programs emphasize power analysis as a tool to determine the sampling effort necessary to effectively document ecologically significant changes in ecosystems. Programs that monitor entire multispecies assemblages require a method for determining the power of multivariate statistical models to detect trend. We provide a method to simulate presence-absence species assemblage data that are consistent with increasing or decreasing directional change in species composition within multiple sites. This step is the foundation for using Monte Carlo methods to approximate the power of any multivariate method for detecting temporal trends. We focus on comparing the power of the Mantel test, permutational multivariate analysis of variance, and constrained analysis of principal coordinates. We find that the power of the various methods we investigate is sensitive to the number of species in the community, univariate species patterns, and the number of sites sampled over time. For increasing directional change scenarios, constrained analysis of principal coordinates was as or more powerful than permutational multivariate analysis of variance, the Mantel test was the least powerful. However, in our investigation of decreasing directional change, the Mantel test was typically as or more powerful than the other models.

Does intrapleural length and position of the intercostal drain affect the frequency of residual hemothorax? A prospective study from north India

PubMed Central

Kumar, Sunil; Agarwal, Nitin; Rattan, Amulya; Rathi, Vinita

2014-01-01

Context: Thoracic trauma causes significant morbidity; however, many deaths are preventable and few patients require surgery. Intercostal chest drainage (ICD) for hemo/pneumothorax is simple and effective; the main problem is residual hemothorax, which can cause lung collapse and empyema. Aims: Our study aimed to analyze the relationship between radiological chest tube parameters (position and intrathoracic length) and the frequency of residual hemothorax. Settings and Design: This prospective analytical study was conducted in a large tertiary care hospital in north India over 2 years till March 2013. Materials and Methods: Patients of chest trauma aged 18-60 years, with hemothorax or hemopneumothorax requiring ICD insertion were included in the study. Bedside ICD insertion was performed as per current standards. Immediate post-ICD chest radiographs were used to record lung status and ICD position (chest tube zone and intrapleural length). Residual hemothorax was defined as any collection identified on radiological investigations after 48 hours of ICD placement. Statistical Analysis: Univariate analysis was performed with the chi-square test or Student's t-test as appropriate, while multivariate analysis using stepwise logistic regression; a P-value < 0.05 was significant. Results: Out of 170 patients of chest trauma, 154 underwent ICD insertion. Most patients were young (mean age: 31.7 ± 12 years) males (M:F = 14:1). Ninety-seven patients (57.1%) had isolated chest injuries. Blunt trauma (n = 119; 77.3%) and motor vehicle accidents (n = 72; 46.7%) were the commonest causes. Mean hospital stay was 9 ± 3.94 days, and mortality 2/154 (1.1%). Residual hemothorax was seen in 48 (31%). No ICD zone or length was significantly associated with residual hemothorax on univariate or multivariate analysis. Conclusion: Intrapleural ICD zone or length does not affect the frequency of residual hemothorax. PMID:25400388

Predictors of Grade 3 or Higher Late Bowel Toxicity in Patients Undergoing Pelvic Radiation for Cervical Cancer: Results From a Prospective Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chopra, Supriya, E-mail: schopra@actrec.gov.in; Dora, Tapas; Chinnachamy, Anand N.

Purpose: The present study investigates relationship between dose–volume parameters and severe bowel toxicity after postoperative radiation treatment (PORT) for cervical cancer. Methods and Materials: From June 2010 to December 2012, a total of 71 patients undergoing PORT were included. Small bowel (SB) and large bowel (LB) loops were contoured 2 cm above the target volume. The volume of SB and LB that received 15 Gy, 30 Gy, and 40 Gy was calculated (V15 SB, V15 LB, V30 SB, V30 LB, V40 SB, V 40 LB). On follow-up, bowel toxicity was scored using Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. A reciever operatingmore » characteristic (ROC) curve identified volume thresholds that predicted for grade 3 or higher toxicity with highest specificity. All data was dichotomized across these identified cut-off values. Univariate and multivariate analysis was performed using SPSS, version 15. Results: The median patient age was 47 years (range, 35-65 years). Of the 71 patients, 46 received image-guided intensity modulated radiation therapy, and 25 received conformal radiation (50 Gy in 25 fractions for 5 weeks). Overall, 63 of 71 patients received concurrent chemotherapy. On a median follow-up of 18 months (range, 8-29 months), grade 2 or higher bowel toxicity was seen in 22 of 71 patients (30.9%) and grade 3 or higher bowel toxicity was seen in 9 patients (12.6%). On univariate analysis, V15 SB <275 cc (P=.01), V30 SB <190 cc (P=.02), V40 SB <150 cc (P=.01), and V15 LB <250 cc (P=.03), and V40 LB <90 cc (P=.04) predicted for absence of grade 3 or higher toxicity. No other patient- or treatment-related factors were statistically significant. On multivariate analysis, only V15 SB (P=.002) and V15 LB (P=.03) were statistically significant. Conclusions: V 15 Gy SB and LB are independent predictors of late grade 3 or higher toxicity. Restricting V15 SB and V15 LB to <275 cc and <250 cc can reduce grade 3 or higher toxicity to less than 5%.« less

Appearance Matters: Neural Correlates of Food Choice and Packaging Aesthetics

PubMed Central

Van der Laan, Laura N.; De Ridder, Denise T. D.; Viergever, Max A.; Smeets, Paul A. M.

2012-01-01

Neuro-imaging holds great potential for predicting choice behavior from brain responses. In this study we used both traditional mass-univariate and state-of-the-art multivariate pattern analysis to establish which brain regions respond to preferred packages and to what extent neural activation patterns can predict realistic low-involvement consumer choices. More specifically, this was assessed in the context of package-induced binary food choices. Mass-univariate analyses showed that several regions, among which the bilateral striatum, were more strongly activated in response to preferred food packages. Food choices could be predicted with an accuracy of up to 61.2% by activation patterns in brain regions previously found to be involved in healthy food choices (superior frontal gyrus) and visual processing (middle occipital gyrus). In conclusion, this study shows that mass-univariate analysis can detect small package-induced differences in product preference and that MVPA can successfully predict realistic low-involvement consumer choices from functional MRI data. PMID:22848586

Flood risk analysis for flood control and sediment transportation in sandy regions: A case study in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Guo, Aijun; Chang, Jianxia; Wang, Yimin; Huang, Qiang; Zhou, Shuai

2018-05-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on regional flood control systems. This work advances traditional flood risk analysis by proposing a univariate and copula-based bivariate hydrological risk framework which incorporates both flood control and sediment transport. In developing the framework, the conditional probabilities of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula-based model. Moreover, a Monte Carlo-based algorithm is designed to quantify the sampling uncertainty associated with univariate and bivariate hydrological risk analyses. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The univariate and bivariate return periods, risk and reliability in the context of uncertainty for the purposes of flood control and sediment transport are assessed for the study regions. The results indicate that sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the event that AMF exceeds the design flood of downstream hydraulic structures in the UCX and UCH. Moreover, there is considerable sampling uncertainty affecting the univariate and bivariate hydrologic risk evaluation, which greatly challenges measures of future flood mitigation. In addition, results also confirm that the developed framework can estimate conditional probabilities associated with different flood events under various extreme precipitation scenarios aiming for flood control and sediment transport. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

Meta-Analyses of Diagnostic Accuracy in Imaging Journals: Analysis of Pooling Techniques and Their Effect on Summary Estimates of Diagnostic Accuracy.

PubMed

McGrath, Trevor A; McInnes, Matthew D F; Korevaar, Daniël A; Bossuyt, Patrick M M

2016-10-01

Purpose To determine whether authors of systematic reviews of diagnostic accuracy studies published in imaging journals used recommended methods for meta-analysis, and to evaluate the effect of traditional methods on summary estimates of sensitivity and specificity. Materials and Methods Medline was searched for published systematic reviews that included meta-analysis of test accuracy data limited to imaging journals published from January 2005 to May 2015. Two reviewers independently extracted study data and classified methods for meta-analysis as traditional (univariate fixed- or random-effects pooling or summary receiver operating characteristic curve) or recommended (bivariate model or hierarchic summary receiver operating characteristic curve). Use of methods was analyzed for variation with time, geographical location, subspecialty, and journal. Results from reviews in which study authors used traditional univariate pooling methods were recalculated with a bivariate model. Results Three hundred reviews met the inclusion criteria, and in 118 (39%) of those, authors used recommended meta-analysis methods. No change in the method used was observed with time (r = 0.54, P = .09); however, there was geographic (χ(2) = 15.7, P = .001), subspecialty (χ(2) = 46.7, P < .001), and journal (χ(2) = 27.6, P < .001) heterogeneity. Fifty-one univariate random-effects meta-analyses were reanalyzed with the bivariate model; the average change in the summary estimate was -1.4% (P < .001) for sensitivity and -2.5% (P < .001) for specificity. The average change in width of the confidence interval was 7.7% (P < .001) for sensitivity and 9.9% (P ≤ .001) for specificity. Conclusion Recommended methods for meta-analysis of diagnostic accuracy in imaging journals are used in a minority of reviews; this has not changed significantly with time. Traditional (univariate) methods allow overestimation of diagnostic accuracy and provide narrower confidence intervals than do recommended (bivariate) methods. (©) RSNA, 2016 Online supplemental material is available for this article.

Fibroblast Growth Factor 2-A Predictor of Outcome for Patients Irradiated for Stage II-III Non-Small-Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rades, Dirk, E-mail: Rades.Dirk@gmx.net; Setter, Cornelia; Dahl, Olav

2012-01-01

Purpose: The prognostic value of the tumor cell expression of the fibroblast growth factor 2 (FGF-2) in patients with non-small-cell lung cancer (NSCLC) is unclear. The present study investigated the effect of tumor cell expression of FGF-2 on the outcome of 60 patients irradiated for Stage II-III NSCLC. Methods and Materials: The effect of FGF-2 expression and 13 additional factors on locoregional control (LRC), metastasis-free survival (MFS), and overall survival (OS) were retrospectively evaluated. These additional factors included age, gender, Karnofsky performance status, histologic type, histologic grade, T and N category, American Joint Committee on Cancer stage, surgery, chemotherapy, pack-years,more » smoking during radiotherapy, and hemoglobin during radiotherapy. Locoregional failure was identified by endoscopy or computed tomography. Univariate analyses were performed with the Kaplan-Meier method and the Wilcoxon test and multivariate analyses with the Cox proportional hazard model. Results: On univariate analysis, improved LRC was associated with surgery (p = .017), greater hemoglobin levels (p = .036), and FGF-2 negativity (p <.001). On multivariate analysis of LRC, surgery (relative risk [RR], 2.44; p = .037), and FGF-2 expression (RR, 5.06; p <.001) maintained significance. On univariate analysis, improved MFS was associated with squamous cell carcinoma (p = .020), greater hemoglobin levels (p = .007), and FGF-2 negativity (p = .001). On multivariate analysis of MFS, the hemoglobin levels (RR, 2.65; p = .019) and FGF-2 expression (RR, 3.05; p = .004) were significant. On univariate analysis, improved OS was associated with a lower N category (p = .048), greater hemoglobin levels (p <.001), and FGF-2 negativity (p <.001). On multivariate analysis of OS, greater hemoglobin levels (RR, 4.62; p = .002) and FGF-2 expression (RR, 3.25; p = .002) maintained significance. Conclusions: Tumor cell expression of FGF-2 appeared to be an independent negative predictor of LRC, MFS, and OS.« less

The association between overactive bladder and fibromyalgia syndrome: a community survey.

PubMed

Chung, Jae Hoon; Kim, Shin Ah; Choi, Bo Youl; Lee, Hye-Soon; Lee, Seung Wook; Kim, Yong Tae; Lee, Tchun Yong; Moon, Hong Sang

2013-01-01

Fibromyalgia syndrome (FMS) is the most common disease causing chronic generalized pain, and FMS patients often complain of urinary symptoms such as frequency or urgency. This study focuses on the association of overactive bladder (OAB) and FMS in adults aged 40 and over. A survey of adults aged 40s and over was conducted in the Guri and Yangpyeong areas of South Korea. The response rate was 74.2% (940/1,266). After excluding subjects with incomplete questionnaires (n = 20), 920 were included in the final analysis. The association of FMS and OAB was analyzed by univariate and multivariate logistic regression analysis. Individuals with FMS had a significantly increased symptoms of OAB after adjustment for gender, age group, and area of residence (odds ratio (OR) 3.39, 95% confidence interval (CI) 1.82-6.31). The association between FMS and severity of OAB was statistical significant (P for trend <0.0001). OAB is associated with FMS. Moreover FMS increases with severity of OAB. Copyright © 2012 Wiley Periodicals, Inc.

PRETREATMENT NUTRITIONAL STATUS AND LOCOREGIONAL FAILURE IN PATIENTS WITH HEAD AND NECK CANCER UNDERGOING DEFINITIVE CONCURRENT CHEMORADIATION THERAPY

PubMed Central

Platek, Mary E.; Reid, Mary E.; Wilding, Gregory E.; Jaggernauth, Wainwright; Rigual, Nestor R.; Hicks, Wesley L.; Popat, Saurin R.; Warren, Graham W.; Sullivan, Maureen; Thorstad, Wade L.; Khan, Mohamed K.; Loree, Thom R.; Singh, Anurag K.

2015-01-01

Background This study was carried out to determine if markers of nutritional status predict for locoregional failure following intensity-modulated radiation therapy (IMRT) with concurrent chemoradiotherapy (CCRT) for squamous cell carcinoma of the head and neck (SCCHN). Methods We performed a retrospective chart review of 78 patients with SCCHN who received definitive CCRT. We compared patient factors, tumor characteristics, and nutritional status indicators between patients with and without locoregional failure. Results Fifteen of 78 patients (19%) experienced locoregional failure. Median follow-up for live patients was 38 months. On univariate analysis, pretreatment percentage of ideal body weight (%IBW) (p < .01), pretreatment hemoglobin (p = .04), and treatment duration (p < .01) were significant predictors of failure. On multivariate analysis, pretreatment %IBW (p = .04) and treatment time (p < .01) remained statistically significant. Conclusions Although treatment time is an accepted risk factor for failure, differences in outcome for patients with head and neck cancer undergoing definitive CCRT based on pre-treatment %IBW should be examined further. PMID:21990220

Incidence of cerebral infarction after radiotherapy for pituitary adenoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flickinger, J.C.; Nelson, P.B.; Taylor, F.H.

1989-06-15

The incidence of cerebral infarction was studied in 156 patients irradiated for treatment of pituitary adenomas. Seven patients experienced strokes at intervals of 3.2 to 14.6 years after irradiation. The observed incidence was not significantly greater than the expected value of 3.5 strokes (P = 0.078). Six strokes occurred in patients receiving equivalent doses (ED) of 1070 ret or more (observed to expected ratio 3.87, significantly elevated; P less than 0.001). Univariate log-rank analysis showed that the risk of stroke was significantly higher (P = 0.010) in patients receiving an ED of 1070 ret or more (4180 cGy/22 fractions) thanmore » those receiving lower doses. Multivariate analysis, however, demonstrated that the increased risk of stroke was associated only with increasing age (P less than 0.0001), not ED (P = 0.148). Due to these inconsistent statistical results, no definitive conclusions could be reached about the relationship between radiation dose to the pituitary and subsequent cerebral infarction.« less

Clinical evaluation of post-operative cerebral infarction in traumatic epidural haematoma.

PubMed

Zhang, Suojun; Wang, Sheng; Wan, Xueyan; Liu, Shengwen; Shu, Kai; Lei, Ting

2017-01-01

Patients with traumatic epidural haematoma, undergoing the prompt and correct treatment, usually have favourable outcomes. However, secondary cerebral infarction may be life-threatening condition, as it is difficult to be identified before neurological impairment occurs. To evaluate the clinical data of patients with traumatic EDH and assess potential risk factors for post-operative cerebral infarction. The clinical data of patients with traumatic EDH were collected and analysed retrospectively. The univariate analysis revealed 10 potential risk factors (the haematoma location, volume, the largest thickness and mid-line shift, basal cisterns compression, traumatic subarachnoid haemorrhage, pupil dilatation, pre-operative Glasgow Coma Scale score, ∆GCS and intraoperative brain pressure) for cerebral infarction with statistically significant difference. Of these factors, haematoma volume and basal cistern compression turned out to be the most significant risk factors through final multivariate logistic regression analysis. The findings of this study can provide predictive factors for development of cerebral infarction and information for clinical decision-making and future studies.

Identification of petroleum hydrocarbons using a reduced number of PAHs selected by Procrustes rotation.

PubMed

Fernández-Varela, R; Andrade, J M; Muniategui, S; Prada, D; Ramírez-Villalobos, F

2010-04-01

Identifying petroleum-related products released into the environment is a complex and difficult task. To achieve this, polycyclic aromatic hydrocarbons (PAHs) are of outstanding importance nowadays. Despite traditional quantitative fingerprinting uses straightforward univariate statistical analyses to differentiate among oils and to assess their sources, a multivariate strategy based on Procrustes rotation (PR) was applied in this paper. The aim of PR is to select a reduced subset of PAHs still capable of performing a satisfactory identification of petroleum-related hydrocarbons. PR selected two subsets of three (C(2)-naphthalene, C(2)-dibenzothiophene and C(2)-phenanthrene) and five (C(1)-decahidronaphthalene, naphthalene, C(2)-phenanthrene, C(3)-phenanthrene and C(2)-fluoranthene) PAHs for each of the two datasets studied here. The classification abilities of each subset of PAHs were tested using principal components analysis, hierarchical cluster analysis and Kohonen neural networks and it was demonstrated that they unraveled the same patterns as the overall set of PAHs. (c) 2009 Elsevier Ltd. All rights reserved.

Prognostic factors in patients with advanced cancer: use of the patient-generated subjective global assessment in survival prediction.

PubMed

Martin, Lisa; Watanabe, Sharon; Fainsinger, Robin; Lau, Francis; Ghosh, Sunita; Quan, Hue; Atkins, Marlis; Fassbender, Konrad; Downing, G Michael; Baracos, Vickie

2010-10-01

To determine whether elements of a standard nutritional screening assessment are independently prognostic of survival in patients with advanced cancer. A prospective nested cohort of patients with metastatic cancer were accrued from different units of a Regional Palliative Care Program. Patients completed a nutritional screen on admission. Data included age, sex, cancer site, height, weight history, dietary intake, 13 nutrition impact symptoms, and patient- and physician-reported performance status (PS). Univariate and multivariate survival analyses were conducted. Concordance statistics (c-statistics) were used to test the predictive accuracy of models based on training and validation sets; a c-statistic of 0.5 indicates the model predicts the outcome as well as chance; perfect prediction has a c-statistic of 1.0. A training set of patients in palliative home care (n = 1,164) was used to identify prognostic variables. Primary disease site, PS, short-term weight change (either gain or loss), dietary intake, and dysphagia predicted survival in multivariate analysis (P < .05). A model including only patients separated by disease site and PS with high c-statistics between predicted and observed responses for survival in the training set (0.90) and validation set (0.88; n = 603). The addition of weight change, dietary intake, and dysphagia did not further improve the c-statistic of the model. The c-statistic was also not altered by substituting physician-rated palliative PS for patient-reported PS. We demonstrate a high probability of concordance between predicted and observed survival for patients in distinct palliative care settings (home care, tertiary inpatient, ambulatory outpatient) based on patient-reported information.

Locality-specific variation in the feeding of Sparus aurata L.: evidence from two Mediterranean lagoon systems

NASA Astrophysics Data System (ADS)

Tancioni, L.; Mariani, S.; Maccaroni, A.; Mariani, A.; Massa, F.; Scardi, M.; Cataudella, S.

2003-06-01

A large number of juvenile, sub-adult and adult individuals of Sparus aurata were collected in two adjacent Mediterranean coastal lagoons, Lake Fogliano and Lake Caprolace, located on the central Tyrrhenian coast of Italy. A comprehensive analysis of the feeding habits of this species was carried out using both univariate and multivariate statistical methods. The results showed that qualitative and quantitative changes in the diet of this species take place within the first months of development. Considerable feeding differences between sub-adult and adult individuals of two bream populations were found in the different coastal lagoons: specimens from Fogliano showed a significantly less diverse trophic spectrum, whereas specimens from Caprolace tended to feed on a larger variety of prey. The ecological significance of these differences and their implications for ecosystem management and conservation are discussed.

A joint probability approach for coincidental flood frequency analysis at ungauged basin confluences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cheng

2016-03-12

A reliable and accurate flood frequency analysis at the confluence of streams is of importance. Given that long-term peak flow observations are often unavailable at tributary confluences, at a practical level, this paper presents a joint probability approach (JPA) to address the coincidental flood frequency analysis at the ungauged confluence of two streams based on the flow rate data from the upstream tributaries. One case study is performed for comparison against several traditional approaches, including the position-plotting formula, the univariate flood frequency analysis, and the National Flood Frequency Program developed by US Geological Survey. It shows that the results generatedmore » by the JPA approach agree well with the floods estimated by the plotting position and univariate flood frequency analysis based on the observation data.« less

The role of environmental heterogeneity in meta-analysis of gene-environment interactions with quantitative traits.

PubMed

Li, Shi; Mukherjee, Bhramar; Taylor, Jeremy M G; Rice, Kenneth M; Wen, Xiaoquan; Rice, John D; Stringham, Heather M; Boehnke, Michael

2014-07-01

With challenges in data harmonization and environmental heterogeneity across various data sources, meta-analysis of gene-environment interaction studies can often involve subtle statistical issues. In this paper, we study the effect of environmental covariate heterogeneity (within and between cohorts) on two approaches for fixed-effect meta-analysis: the standard inverse-variance weighted meta-analysis and a meta-regression approach. Akin to the results in Simmonds and Higgins (), we obtain analytic efficiency results for both methods under certain assumptions. The relative efficiency of the two methods depends on the ratio of within versus between cohort variability of the environmental covariate. We propose to use an adaptively weighted estimator (AWE), between meta-analysis and meta-regression, for the interaction parameter. The AWE retains full efficiency of the joint analysis using individual level data under certain natural assumptions. Lin and Zeng (2010a, b) showed that a multivariate inverse-variance weighted estimator retains full efficiency as joint analysis using individual level data, if the estimates with full covariance matrices for all the common parameters are pooled across all studies. We show consistency of our work with Lin and Zeng (2010a, b). Without sacrificing much efficiency, the AWE uses only univariate summary statistics from each study, and bypasses issues with sharing individual level data or full covariance matrices across studies. We compare the performance of the methods both analytically and numerically. The methods are illustrated through meta-analysis of interaction between Single Nucleotide Polymorphisms in FTO gene and body mass index on high-density lipoprotein cholesterol data from a set of eight studies of type 2 diabetes. © 2014 WILEY PERIODICALS, INC.

Factors influencing health professions students' use of computers for data analysis at three Ugandan public medical schools: a cross-sectional survey.

PubMed

Munabi, Ian G; Buwembo, William; Bajunirwe, Francis; Kitara, David Lagoro; Joseph, Ruberwa; Peter, Kawungezi; Obua, Celestino; Quinn, John; Mwaka, Erisa S

2015-02-25

Effective utilization of computers and their applications in medical education and research is of paramount importance to students. The objective of this study was to determine the association between owning a computer and use of computers for research data analysis and the other factors influencing health professions students' computer use for data analysis. We conducted a cross sectional study among undergraduate health professions students at three public universities in Uganda using a self-administered questionnaire. The questionnaire was composed of questions on participant demographics, students' participation in research, computer ownership, and use of computers for data analysis. Descriptive and inferential statistics (uni-variable and multi- level logistic regression analysis) were used to analyse data. The level of significance was set at 0.05. Six hundred (600) of 668 questionnaires were completed and returned (response rate 89.8%). A majority of respondents were male (68.8%) and 75.3% reported owning computers. Overall, 63.7% of respondents reported that they had ever done computer based data analysis. The following factors were significant predictors of having ever done computer based data analysis: ownership of a computer (adj. OR 1.80, p = 0.02), recently completed course in statistics (Adj. OR 1.48, p =0.04), and participation in research (Adj. OR 2.64, p <0.01). Owning a computer, participation in research and undertaking courses in research methods influence undergraduate students' use of computers for research data analysis. Students are increasingly participating in research, and thus need to have competencies for the successful conduct of research. Medical training institutions should encourage both curricular and extra-curricular efforts to enhance research capacity in line with the modern theories of adult learning.

Integrative set enrichment testing for multiple omics platforms

PubMed Central

2011-01-01

Background Enrichment testing assesses the overall evidence of differential expression behavior of the elements within a defined set. When we have measured many molecular aspects, e.g. gene expression, metabolites, proteins, it is desirable to assess their differential tendencies jointly across platforms using an integrated set enrichment test. In this work we explore the properties of several methods for performing a combined enrichment test using gene expression and metabolomics as the motivating platforms. Results Using two simulation models we explored the properties of several enrichment methods including two novel methods: the logistic regression 2-degree of freedom Wald test and the 2-dimensional permutation p-value for the sum-of-squared statistics test. In relation to their univariate counterparts we find that the joint tests can improve our ability to detect results that are marginal univariately. We also find that joint tests improve the ranking of associated pathways compared to their univariate counterparts. However, there is a risk of Type I error inflation with some methods and self-contained methods lose specificity when the sets are not representative of underlying association. Conclusions In this work we show that consideration of data from multiple platforms, in conjunction with summarization via a priori pathway information, leads to increased power in detection of genomic associations with phenotypes. PMID:22118224

Definitive or conservative surgery for perforated gastric ulcer?--An unresolved problem.

PubMed

Sarath Chandra, Sistla; Kumar, S Siva

2009-04-01

Gastric ulcer perforation has not been the focus of many studies. In addition there is a need to analyze the results of gastric perforation separately and not along with duodenal perforations, to identify the factors influencing the outcome and to develop strategies for its management. Retrospective analysis of 54 patients presenting with gastric perforation. Mean age of the patients was 44.5 years with male preponderance. Morbidity following Closure of the perforation, acid reduction surgery and resection was not significantly different. Overall mortality was 16.6% with highest mortality 24.1% following simple closure. Mortality following simple closure and definitive surgery was not significantly different. Univariate analysis revealed preoperative shock, associated medical illness and surgical delay to be significant factors for mortality whereas on multivariate analysis, preoperative shock was the only independent predictor of mortality. Mortality increased with increasing Boey score but the association between the type of surgery and probability of survival was not statistically significant. Boey risk score is useful in predicting the outcome of surgical treatment for gastric perforation. Definitive surgery is not associated with greater morbidity or mortality compared to simple closure.

Detection of Patient Subgroups with Differential Expression in Omics Data: A Comprehensive Comparison of Univariate Measures

PubMed Central

Ahrens, Maike; Turewicz, Michael; Casjens, Swaantje; May, Caroline; Pesch, Beate; Stephan, Christian; Woitalla, Dirk; Gold, Ralf; Brüning, Thomas; Meyer, Helmut E.

2013-01-01

Detection of yet unknown subgroups showing differential gene or protein expression is a frequent goal in the analysis of modern molecular data. Applications range from cancer biology over developmental biology to toxicology. Often a control and an experimental group are compared, and subgroups can be characterized by differential expression for only a subgroup-specific set of genes or proteins. Finding such genes and corresponding patient subgroups can help in understanding pathological pathways, diagnosis and defining drug targets. The size of the subgroup and the type of differential expression determine the optimal strategy for subgroup identification. To date, commonly used software packages hardly provide statistical tests and methods for the detection of such subgroups. Different univariate methods for subgroup detection are characterized and compared, both on simulated and on real data. We present an advanced design for simulation studies: Data is simulated under different distributional assumptions for the expression of the subgroup, and performance results are compared against theoretical upper bounds. For each distribution, different degrees of deviation from the majority of observations are considered for the subgroup. We evaluate classical approaches as well as various new suggestions in the context of omics data, including outlier sum, PADGE, and kurtosis. We also propose the new FisherSum score. ROC curve analysis and AUC values are used to quantify the ability of the methods to distinguish between genes or proteins with and without certain subgroup patterns. In general, FisherSum for small subgroups and -test for large subgroups achieve best results. We apply each method to a case-control study on Parkinson's disease and underline the biological benefit of the new method. PMID:24278130

A prognostic index for predicting lymph node metastasis in minor salivary gland cancer.

PubMed

Lloyd, Shane; Yu, James B; Ross, Douglas A; Wilson, Lynn D; Decker, Roy H

2010-01-01

Large studies examining the clinical and pathological factors associated with nodal metastasis in minor salivary gland cancer are lacking in the literature. Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 2,667 minor salivary gland cancers with known lymph node status from 1988 to 2004. Univariate and multivariate analyses were conducted to identify factors associated with the use of neck dissection, the use of external beam radiation therapy, and the presence of cervical lymph node metastases. Four hundred twenty-six (16.0%) patients had neck nodal involvement. Factors associated with neck nodal involvement on univariate analysis included increasing age, male sex, increasing tumor size, high tumor grade, T3-T4 stage, adenocarcinoma or mucoepidermoid carcinomas, and pharyngeal site of primary malignancy. On multivariate analysis, four statistically significant factors were identified, including male sex, T3-T4 stage, pharyngeal site of primary malignancy, and high-grade adenocarcinoma or high-grade mucoepidermoid carcinomas. The proportions (and 95% confidence intervals) of patients with lymph node involvement for those with 0, 1, 2, 3, and 4 of these prognostic factors were 0.02 (0.01-0.03), 0.09 (0.07-0.11), 0.17 (0.14-0.21), 0.41 (0.33-0.49), and 0.70 (0.54-0.85), respectively. Grade was a significant predictor of metastasis for adenocarcinoma and mucoepidermoid carcinoma but not for adenoid cystic carcinoma. A prognostic index using the four clinicopathological factors listed here can effectively differentiate patients into risk groups of nodal metastasis. The precision of this index is subject to the limitations of SEER data and should be validated in further clinical studies.

Medical impulsive therapy (MIT): the impact of 1 week of preoperative tamsulosin on deployment of 16-French ureteral access sheaths without preoperative ureteral stent placement.

PubMed

Kaler, Kamaljot S; Safiullah, Shoaib; Lama, Daniel J; Parkhomenko, Egor; Okhunov, Zhamshid; Ko, Young H; Huynh, Linda; Patel, Roshan M; Landman, Jaime; Clayman, Ralph V

2018-05-25

Medical expulsive therapy is based on pharmacologic ureteral relaxation. We hypothesized this concept may facilitate the deployment of the large 16 French (F) ureteral access sheath (UAS) when patients are intentionally pre-treated with oral tamsulosin, i.e., medical impulsive therapy. We retrospectively analyzed our experience with UAS deployment during endoscopic-guided percutaneous nephrolithotomy in prone position in patients pre-treated for 1 week with oral tamsulosin with a contemporary untreated cohort. Between January 2015 and September 2016, seventy-seven patients without a pre-existing ureteral stent met inclusion criteria. Demographic data, tamsulosin usage, UAS size, deployment failure, ureteral injuries, stone-free rates, and complications were recorded. Univariate and multivariate analysis was conducted to assess the impact of tamsulosin on deployment of the 16F UAS. There was no statistical difference between the tamsulosin (n = 40) group and non-tamsulosin (n = 37) group in regard to demographic data. The tamsulosin group had a significantly higher percentage of 16F UAS deployment, 87 vs. 43% (p < 0.001), and no significant difference in ureteral injuries (p = 0.228). Univariate and multivariate analysis revealed that tamsulosin significantly increased the odds ratio (9.3 and 19.4, respectively) for successful passage of a 16F UAS. Despite a larger stone volume, there was no significant difference in computed tomography scan complete stone-free rates (29 vs. 42%; p = 0.277) at median post-operative time of only 3 days. In this retrospective study, 1 week of preoperative tamsulosin was associated with an increase in the deployment of a 16F UAS in patients without preoperative ureteral stent placement.

Self-injurious behavior among Greek male prisoners: prevalence and risk factors.

PubMed

Sakelliadis, E I; Papadodima, S A; Sergentanis, T N; Giotakos, O; Spiliopoulou, C A

2010-04-01

Self-harm among prisoners is a common phenomenon. This study aims to estimate the prevalence of self-injurious behavior (SIB) among Greek male prisoners, record their motives and determine independent risk factors. A self-administered, anonymous questionnaire was administered to 173 male prisoners in the Chalkida prison, Greece. The questionnaire included items on self-harm/SIB, demographic parameters, childhood history, family history, physical and mental disease, lifestyle and smoking habits, alcohol dependence (CAGE questionnaire), illicit substance use, aggression (Buss-Perry Aggression Questionnaire [BPAQ] and Lifetime History of Aggression [LTHA]), impulsivity (Barrat Impulsivity Scale-11) and suicidal ideation (Spectrum of Suicidal Behavior Scale). Univariate nonparametric statistics and multivariate ordinal logistic regression were performed. Of all the participants, 49.4% (95% CI: 41.5-57.3%) disclosed self-harm (direct or indirect). The prevalence of SIB was equal to 34.8% (95% CI: 27.5-42.6%). Most frequently, SIB coexisted with indirect self-harm (80.7%). The most common underlying motives were to obtain emotional release (31.6%) and to release anger (21.1%). At the univariate analysis, SIB was positively associated with a host of closely related factors: low education, physical/sexual abuse in childhood, parental neglect, parental divorce, alcoholism in family, psychiatric condition in family, recidivism, age, sentence already served, impulsivity, aggression, alcohol dependence, self-reported diagnosed psychiatric condition and illicit substance use. Childhood variables were particularly associated with the presence of diagnosed psychiatric condition. At the multivariate analysis, however, only three parameters were proven independent risk factors: self-reported diagnosed psychiatric condition, illicit substance use and aggression (BPAQ scale). The prevalence of SIB is particularly high. Psychiatric condition, illicit substance use and aggression seem to be the most meaningful risk factors; childhood events seem only to act indirectly. Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.

The impact of social deprivation on coronary revascularisation treatment outcomes within the National Health Service in England and Wales.

PubMed

Matata, Bashir M; Shaw, Matthew; Grayson, Antony D; McShane, James; Lucy, John; Fisher, Michael; Jackson, Mark

2016-02-01

There is strong evidence to suggest that social deprivation is linked to health inequalities. In the UK, concerns have been raised regarding disparities in the outcomes of acute cardiac services within the National Health Service (NHS). This study explored whether differences exist in (a) elective hospital presentation time (b) indicators of severity and disease burden and (c) treatment outcomes (hospital stay and mortality) on the basis of the index of multiple deprivation (IMD) status. This study was a retrospective analysis of data from NHS databases for 13,758 patients that had undergone cardiac revascularisation interventions at the Liverpool Heart and Chest Hospital between April 2007-March 2012. The data was analysed by descriptive, univariate and multivariate statistics to explore the association between the IMD quintiles (Q1-Q5) and revascularisation type, elective presentation time, hospital length of stay and mortality. Univariate analysis indicated that there were significant differences between patients from the most deprived areas (Q5) compared with patients from the least deprived areas (Q1), these included admission volumes, time before presentation to hospital and proportion of non-elective cases. After risk-adjustments, percutaneous coronary intervention patients from Q5 compared with Q1 had significantly greater length of hospital stay and risk of in-hospital major acute cardiovascular events. After multivariate adjustment for baseline risk factors, patients from Q5 were associated with significantly worse five-year survival as compared with Q1 (hazard ratio (HR) 1.52, 95% confidence interval (CI): 1.36-1.71; p < 0.001). In conclusion, there is evidence to suggest that inequalities in cardiac revascularisation choices and outcomes in the UK may be associated with social deprivation. © The European Society of Cardiology 2015.

Characterizing job satisfaction and intent to leave among nationally registered emergency medical technicians: an analysis of the 2005 LEADS survey.

PubMed

Patterson, P Daniel; Moore, Charity G; Sanddal, Nels D; Wingrove, Gary; LaCroix, Brian

2009-01-01

The primary purpose of this study was to characterize job satisfaction with opportunities for advancement, job satisfaction with pay and benefits, and intent to leave the EMS profession among Nationally Registered EMT-Basics and EMT-Paramedics. A secondary data analysis was performed on the National Registry of EMTs Longitudinal Emergency Medical Technician Attributes and Demographic Study Project (LEADS) 2005 core survey. We used chi-square and multiple logistic regression analyses to test for differences in job satisfaction with opportunities for advancement, job satisfaction with pay and benefits, and intent to leave the EMS profession across years of experience and work location. Among 11 measures of job satisfaction, NREMT-Basics and NREMT-Paramedics were least satisfied with opportunities for advancement and pay and benefits (67.8 and 55.2%, respectively). Nearly 6% of respondents reported intentions of leaving the profession within 12 months. In univariate analyses, job satisfaction with advancement opportunities varied across years of experience and work location. Job satisfaction with pay and benefits varied across years of experience and work location. The proportion reporting intentions of leaving the profession did not vary across the two independent variables of interest. In multivariable logistic regression, statistical differences observed in univariate analyses were attenuated to non-significance across all outcome models. Income, personal health, level of EMS certification, and type of EMS work were significant in several outcome models. EMS workforce research is at its infancy, thus our study adds to a limited but growing body of knowledge. In future and replicated research, one will need to consider different person and organizational variables in predicting different measures of job satisfaction among EMS personnel.

Prevalence of kidney stones and associated risk factors in the Shunyi District of Beijing, China.

PubMed

Jiang, Y G; He, L H; Luo, G T; Zhang, X D

2017-10-01

Kidney stone formation is a multifactorial condition that involves interaction of environmental and genetic factors. Presence of kidney stones is strongly related to other diseases, which may result in a heavy economic and social burden. Clinical data on the prevalence and influencing factors in kidney stone disease in the north of China are scarce. In this study, we explored the prevalence of kidney stone and potentially associated risk factors in the Shunyi District of Beijing, China. A population-based cross-sectional study was conducted from December 2011 to November 2012 in a northern area of China. Participants were interviewed in randomly selected towns. Univariate analysis of continuous and categorical variables was first performed by calculation of Spearman's correlation coefficient and Pearson Chi squared value, respectively. Variables with statistical significance were further analysed by multivariate logistic regression to explore the potential influencing factors. A total of 3350 participants (1091 males and 2259 females) completed the survey and the response rate was 99.67%. Among the participants, 3.61% were diagnosed with kidney stone. Univariate analysis showed that significant differences were evident in 31 variables. Blood and urine tests were performed in 100 randomly selected patients with kidney stone and 100 healthy controls. Serum creatinine, calcium, and uric acid were significantly different between the patients with kidney stone and healthy controls. Multivariate logistic regression revealed that being male (odds ratio=102.681; 95% confidence interval, 1.062-9925.797), daily intake of white spirits (6.331; 1.204-33.282), and a history of urolithiasis (1797.775; 24.228-133 396.982) were factors potentially associated with kidney stone prevalence. Male gender, drinking white spirits, and a history of urolithiasis are potentially associated with kidney stone formation.

Association between maternal acculturation and health beliefs related to oral health of Latino children.

PubMed

Tiwari, Tamanna; Mulvahill, Matthew; Wilson, Anne; Rai, Nayanjot; Albino, Judith

2018-04-24

This report is presenting the association of maternal acculturation, measured by preferred language, and oral health-related psychosocial measures in an urban Latino population. A cross-sectional survey was conducted with 100 mother-child dyads from the Dental Center at the Children's Hospital Colorado, the University of Colorado. A portion of Basic Research Factors Questionnaire capturing information about parental dental knowledge, attitudes, behavior and psychosocial measures was used to collect data from the participating mothers. Descriptive statistics were calculated for demographics and psychosocial measures by acculturation. A univariate linear regression model was performed for each measure by preferred language for primary analysis followed by adjusted model adjusting for parent's education. The mean age of the children was 3.99 years (SD = 1.11), and that of the mother was 29.54 years (SD = 9.62). Dental caries, measured as dmfs, was significantly higher in children of Spanish-speaking mothers compared to children of English-speaking mothers. English-speaking mothers had higher mean scores of oral health knowledge, oral health behaviors, knowledge on dental utilization, self-efficacy, and Oral Health Locus of Control as compared to Spanish-speaking mothers. Univariate analysis demonstrated significant association for preference for Spanish language with knowledge on dental utilization, maternal self-efficacy, perceived susceptibility and perceived barriers. The effect of language was attenuated, but significant, for each of these variables after adjusting for parent's education. This study reported that higher acculturation measured by a preference for the English language had a positive association with oral health outcomes in children. Spanish-speaking mothers perceived that their children were less susceptible to caries. Additionally, they perceived barriers in visiting the dentist for preventive visits.

Tension-free vaginal tape for treatment of pure urodynamic stress urinary incontinence: efficacy and adverse effects at 17-year follow-up.

PubMed

Braga, Andrea; Caccia, Giorgio; Sorice, Paola; Cantaluppi, Simona; Coluccia, Anna Chiara; Di Dedda, Maria Carmela; Regusci, Luca; Ghezzi, Fabio; Uccella, Stefano; Serati, Maurizio

2018-07-01

To assess the efficacy and safety of retropubic tension-free vaginal tape (TVT) 17 years after implantation for the treatment of female pure stress urinary incontinence (SUI). A prospective study was conducted in two urogynaecological units in two countries. All consecutive women with urodynamically proven pure SUI treated by TVT were included. Patients with mixed incontinence and/or anatomical evidence of pelvic organ prolapse were excluded. Data regarding subjective outcomes (International Consultation on Incontinence Questionnaire-Short Form, Patient Global Impression of Improvement, and patient satisfaction scores), objective cure (stress test) rates, and adverse events were collected during follow-up. Univariable analysis was performed to investigate outcomes. A total of 52 women underwent TVT implantation. At 17-year follow-up, 46 women (88.4%) were available for the evaluation. We did not find any significant change in surgical outcomes during this time. At 17 years after surgery, 41 of 46 women (89.1%) declared themselves cured (P = 0.98). Similarly, at 17-year evaluation, 42 of 46 women (91.4%) were objectively cured. No significant deterioration in objective cure rates was observed over time (P for trend 0.50). The univariate analysis did not find any risk factor statistically associated with the recurrence of SUI. Of the 46 women, 15 (32.6%) reported the onset of de novo overactive bladder at 17-year follow-up. No other late complications were reported. The 17-year results of this study showed that TVT is a highly effective and safe option for the treatment of SUI. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

CDO1 promoter methylation is associated with gene silencing and is a prognostic biomarker for biochemical recurrence-free survival in prostate cancer patients.

PubMed

Meller, Sebastian; Zipfel, Lisa; Gevensleben, Heidrun; Dietrich, Jörn; Ellinger, Jörg; Majores, Michael; Stein, Johannes; Sailer, Verena; Jung, Maria; Kristiansen, Glen; Dietrich, Dimo

2016-12-01

Molecular biomarkers may facilitate the distinction between aggressive and clinically insignificant prostate cancer (PCa), thereby potentially aiding individualized treatment. We analyzed cysteine dioxygenase 1 (CDO1) promoter methylation and mRNA expression in order to evaluate its potential as prognostic biomarker. CDO1 methylation and mRNA expression were determined in cell lines and formalin-fixed paraffin-embedded prostatectomy specimens from a first cohort of 300 PCa patients using methylation-specific qPCR and qRT-PCR. Univariate and multivariate Cox proportional hazards and Kaplan-Meier analyses were performed to evaluate biochemical recurrence (BCR)-free survival. Results were confirmed in an independent second cohort comprising 498 PCa cases. Methylation and mRNA expression data from the second cohort were generated by The Cancer Genome Atlas (TCGA) Research Network by means of Infinium HumanMethylation450 BeadChip and RNASeq. CDO1 was hypermethylated in PCa compared to normal adjacent tissues and benign prostatic hyperplasia (P < 0.001) and was associated with reduced gene expression (ρ = -0.91, P = 0.005). Using two different methodologies for methylation quantification, high CDO1 methylation as continuous variable was associated with BCR in univariate analysis (first cohort: HR = 1.02, P = 0.002, 95% CI [1.01-1.03]; second cohort: HR = 1.02, P = 0.032, 95% CI [1.00-1.03]) but failed to reach statistical significance in multivariate analysis. CDO1 promoter methylation is involved in gene regulation and is a potential prognostic biomarker for BCR-free survival in PCa patients following radical prostatectomy. Further studies are needed to validate CDO1 methylation assays and to evaluate the clinical utility of CDO1 methylation for the management of PCa.

A multi-institutional, propensity-score-matched comparison of post-operative outcomes between general anesthesia and monitored anesthesia care with intravenous sedation in umbilical hernia repair.

PubMed

Vu, M M; Galiano, R D; Souza, J M; Du Qin, C; Kim, J Y S

2016-08-01

Monitored anesthesia care with intravenous sedation (MAC/IV), recently proposed as a good choice for hernia repair, has faster recovery and better patient satisfaction than general anesthesia; however the possibility of oversedation and respiratory distress is a widespread concern. There is a paucity of the literature examining umbilical hernia repairs (UHR) and optimal anesthesia choice, despite its importance in determining clinical outcomes. A retrospective analysis of anesthesia type in UHR was performed in the National Surgical Quality Improvement Program 2005-2013 database. General anesthesia and MAC/IV groups were propensity-score-matched (PSM) to reduce treatment selection bias. Surgical complications, medical complications, and post-operative hospital stays exceeding 1 day were the primary outcomes of interest. Pre-operative characteristics and post-operative outcomes were compared between the two anesthesia groups using univariate and multivariate statistics. PSM removed all observed differences between the two groups (p > 0.05 for all tracked pre-operative characteristics). MAC/IV cases required fewer post-operative hospital stays exceeding 1 day (3.5 vs 6.3 %, p < 0.001). Univariate analysis showed that overall complication rate did not differ (1.7 vs 1.8 %, p = 0.569), however MAC/IV cases resulted in fewer incidences of septic shock (<0.1 vs 0.1 %, p = 0.016). After multivariate logistic regression, MAC/IV was revealed to yield significantly lower chances of overall medical complications (OR = 0.654, p = 0.046). UHR under MAC/IV causes fewer medical complications and reduces post-operative hospital stays compared to general anesthesia. The implications for surgeons and patients are broad, including improved surgical safety, cost-effective care, and patient satisfaction.

MGAS: a powerful tool for multivariate gene-based genome-wide association analysis.

PubMed

Van der Sluis, Sophie; Dolan, Conor V; Li, Jiang; Song, Youqiang; Sham, Pak; Posthuma, Danielle; Li, Miao-Xin

2015-04-01

Standard genome-wide association studies, testing the association between one phenotype and a large number of single nucleotide polymorphisms (SNPs), are limited in two ways: (i) traits are often multivariate, and analysis of composite scores entails loss in statistical power and (ii) gene-based analyses may be preferred, e.g. to decrease the multiple testing problem. Here we present a new method, multivariate gene-based association test by extended Simes procedure (MGAS), that allows gene-based testing of multivariate phenotypes in unrelated individuals. Through extensive simulation, we show that under most trait-generating genotype-phenotype models MGAS has superior statistical power to detect associated genes compared with gene-based analyses of univariate phenotypic composite scores (i.e. GATES, multiple regression), and multivariate analysis of variance (MANOVA). Re-analysis of metabolic data revealed 32 False Discovery Rate controlled genome-wide significant genes, and 12 regions harboring multiple genes; of these 44 regions, 30 were not reported in the original analysis. MGAS allows researchers to conduct their multivariate gene-based analyses efficiently, and without the loss of power that is often associated with an incorrectly specified genotype-phenotype models. MGAS is freely available in KGG v3.0 (http://statgenpro.psychiatry.hku.hk/limx/kgg/download.php). Access to the metabolic dataset can be requested at dbGaP (https://dbgap.ncbi.nlm.nih.gov/). The R-simulation code is available from http://ctglab.nl/people/sophie_van_der_sluis. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

Invariance in the recurrence of large returns and the validation of models of price dynamics

NASA Astrophysics Data System (ADS)

Chang, Lo-Bin; Geman, Stuart; Hsieh, Fushing; Hwang, Chii-Ruey

2013-08-01

Starting from a robust, nonparametric definition of large returns (“excursions”), we study the statistics of their occurrences, focusing on the recurrence process. The empirical waiting-time distribution between excursions is remarkably invariant to year, stock, and scale (return interval). This invariance is related to self-similarity of the marginal distributions of returns, but the excursion waiting-time distribution is a function of the entire return process and not just its univariate probabilities. Generalized autoregressive conditional heteroskedasticity (GARCH) models, market-time transformations based on volume or trades, and generalized (Lévy) random-walk models all fail to fit the statistical structure of excursions.

Toxoplasma gondii in sheep and goats: seroprevalence and potential risk factors under dairy husbandry practices.

PubMed

Tzanidakis, Nikolaos; Maksimov, Pavlo; Conraths, Franz J; Kiossis, Evaggelos; Brozos, Christos; Sotiraki, Smaragda; Schares, Gereon

2012-12-21

Sheep and goats are highly susceptible for infections with Toxoplasma gondii and may play a major role in the transmission of toxoplasmosis to humans. The aim of this study was to obtain up-to-date data on T. gondii infection in small ruminants and to identify putative risk factors in sheep and goats reared under dairy husbandry systems most commonly applied in Greece. To this end, ELISA tests were established for the examination of sheep and goat sera based on the use of TgSAG1, a major surface antigen of T. gondii tachyzoites. Serum samples from 2-4 years old small ruminants, 1501 from sheep and 541 from goats were examined. These samples had been collected on 69 farms in a mountainous and in a costal environment of Northern Greece from September 2008 to January 2009. In addition to farms containing only sheep (n=28) and farms containing only goats (n=9) also mixed farms with both animal species (n=32) were sampled. A standardized questionnaire was used to obtain information on putative risk factors. Sheep showed a higher seroprevalence (48.6% [729/1501]) for T. gondii than goats (30.7% [166/541]). Univariate multi-level modelling assuming random effects by the factor "farm" revealed that goats were statistically significantly less often seropositive than sheep (OR 0.475 [95% CI: 0.318-0.707]). No statistically significant regional differences in seroprevalence were observed. Risk factor analysis using univariate multi-level modelling revealed that sheep and goats that were kept under intensive (OR 4.30 [95% CI: 1.39-13.27]) or semi-intensive (OR 5.35 [95% CI: 2.33-12.28]) conditions had significantly higher odds of being seropositive. Further significant risk factors were "feeding concentrate" (OR 3.88 [95% CI: 1.81-8.29]) and providing "water from the public supply" (OR 1.67 [95% CI: 4.56-12.39]) to small ruminants. Copyright © 2012 Elsevier B.V. All rights reserved.

Economic Expansion Is a Major Determinant of Physician Supply and Utilization

PubMed Central

Cooper, Richard A; Getzen, Thomas E; Laud, Prakash

2003-01-01

Objective To assess the relationship between levels of economic development and the supply and utilization of physicians. Data Sources Data were obtained from the American Medical Association, American Osteopathic Association, Organization for Economic Cooperation and Development (OECD), Bureau of Health Professions, Bureau of Labor Statistics, Bureau of Economic Analysis, Census Bureau, Health Care Financing Administration, and historical sources. Study Design Economic development, expressed as real per capita gross domestic product (GDP) or personal income, was correlated with per capita health care labor and physician supply within countries and states over periods of time spanning 25–70 years and across countries, states, and metropolitan statistical areas (MSAs) at multiple points in time over periods of up to 30 years. Longitudinal data were analyzed in four complementary ways: (1) simple univariate regressions; (2) regressions in which temporal trends were partialled out; (3) time series comparing percentage differences across segments of time; and (4) a bivariate Granger causality test. Cross-sectional data were assessed at multiple time points by means of univariate regression analyses. Principal Findings Under each analytic scenario, physician supply correlated with differences in GDP or personal income. Longitudinal correlations were associated with temporal lags of approximately 5 years for health employment and 10 years for changes in physician supply. The magnitude of changes in per capita physician supply in the United States was equivalent to differences of approximately 0.75 percent for each 1.0 percent difference in GDP. The greatest effects of economic expansion were on the medical specialties, whereas the surgical and hospital-based specialties were affected to a lesser degree, and levels of economic expansion had little influence on family/general practice. Conclusions Economic expansion has a strong, lagged relationship with changes in physician supply. This suggests that economic projections could serve as a gauge for projecting the future utilization of physician services. PMID:12785567

Whole-coal versus ash basis in coal geochemistry: a mathematical approach to consistent interpretations

USGS Publications Warehouse

Geboy, Nicholas J.; Engle, Mark A.; Hower, James C.

2013-01-01

Several standard methods require coal to be ashed prior to geochemical analysis. Researchers, however, are commonly interested in the compositional nature of the whole-coal, not its ash. Coal geochemical data for any given sample can, therefore, be reported in the ash basis on which it is analyzed or the whole-coal basis to which the ash basis data are back calculated. Basic univariate (mean, variance, distribution, etc.) and bivariate (correlation coefficients, etc.) measures of the same suite of samples can be very different depending which reporting basis the researcher uses. These differences are not real, but an artifact resulting from the compositional nature of most geochemical data. The technical term for this artifact is subcompositional incoherence. Since compositional data are forced to a constant sum, such as 100% or 1,000,000 ppm, they possess curvilinear properties which make the Euclidean principles on which most statistical tests rely inappropriate, leading to erroneous results. Applying the isometric logratio (ilr) transformation to compositional data allows them to be represented in Euclidean space and evaluated using traditional tests without fear of producing mathematically inconsistent results. When applied to coal geochemical data, the issues related to differences between the two reporting bases are resolved as demonstrated in this paper using major oxide and trace metal data from the Pennsylvanian-age Pond Creek coal of eastern Kentucky, USA. Following ilr transformation, univariate statistics, such as mean and variance, still differ between the ash basis and whole-coal basis, but in predictable and calculated manners. Further, the stability between two different components, a bivariate measure, is identical, regardless of the reporting basis. The application of ilr transformations addresses both the erroneous results of Euclidean-based measurements on compositional data as well as the inconsistencies observed on coal geochemical data reported on different bases.

Analysis of risk factors of type a aortic dissection (TAAD) operation of frozen elephant trunk and total arch replacement.

PubMed

Shang, W; Ma, M; Ge, Y-P; Liu, N; Zhu, J-M; Sun, L-Z

2016-11-01

To investigate the incidence and risk factors of acute renal failure (ARF) after operation of frozen elephant trunk and total arch replacement for acute thoracic aortic aneurysm and dissection (TAAD) with mild hypothermic circulatory arrest (MHCA), and to analyze the long-term survival rate of the patients with ARF. From February 2009 to March 2015, patients with acute TAAD accepted operation of frozen elephant trunk and total arch replacement were enrolled. Those patients who were treated with renal replacement treatment (RRT) before the operation were excluded. The age, gender, cardiovascular disease history, preoperative serum creatinine and extracorporeal circulation duration in operation were recorded. On the basis of requiring RRT after TAAD operation, the patients were divided into ARF group and non-ARF group. The risk factors of ARF after TAAD operation were assessed by univariate and multivariate analysis. After completion of clinical follow-up, Kaplan-Meier curve was drawn to analyze five-year survival. A total of 524 patients were included in the study. 51 cases of them got postoperative ARF. The incidence was 9.7%. The mortality rate of ARF group in the hospital was significantly higher than non-ARF group (25.5% vs. 3.6%; p<0.001). Univariate analysis showed that there was statistically significant difference in the age, gender, hypertension history, preoperative serum creatinine ≥200 µmol/L, extracorporeal circulation duration ≥260 min and combined with coronary artery bypass surgery simultaneously (p<0.05). Multiple logistic regression analysis showed that there were three independent risk factors of ARF after the operation, including hypertension (p=0.031, OR=2.377), preoperative serum creatinine ≥200 µmol/L (p=0.005, OR=4.451) and extracorporeal circulation duration ≥260 min (p=0.002, OR=3.295). The total five-year survival rate of ARF group after the operation was 56%. There was no statistically significant difference in the five-year survival rate between preoperative serum creatinine ≥200 µmol/L group and <200 µmol/L group (p>0.05). The incidence of ARF after the operation was 9.7%. Preoperative serum creatinine ≥200 µmol/L, hypertension history and extracorporeal circulation duration ≥260 min were independent risk factors of ARF after the operation. The five-year survival rate of ARF after the operation was 56%. The preoperative serum creatinine level had no influence on the postoperative long-term survival.

Empirical likelihood-based tests for stochastic ordering

PubMed Central

BARMI, HAMMOU EL; MCKEAGUE, IAN W.

2013-01-01

This paper develops an empirical likelihood approach to testing for the presence of stochastic ordering among univariate distributions based on independent random samples from each distribution. The proposed test statistic is formed by integrating a localized empirical likelihood statistic with respect to the empirical distribution of the pooled sample. The asymptotic null distribution of this test statistic is found to have a simple distribution-free representation in terms of standard Brownian bridge processes. The approach is used to compare the lengths of rule of Roman Emperors over various historical periods, including the “decline and fall” phase of the empire. In a simulation study, the power of the proposed test is found to improve substantially upon that of a competing test due to El Barmi and Mukerjee. PMID:23874142

Vascular endothelial growth factor (VEGF) expression in locally advanced prostate cancer: secondary analysis of radiation therapy oncology group (RTOG) 8610.

PubMed

Pan, Larry; Baek, Seunghee; Edmonds, Pamela R; Roach, Mack; Wolkov, Harvey; Shah, Satish; Pollack, Alan; Hammond, M Elizabeth; Dicker, Adam P

2013-04-25

Angiogenesis is a key element in solid-tumor growth, invasion, and metastasis. VEGF is among the most potent angiogenic factor thus far detected. The aim of the present study is to explore the potential of VEGF (also known as VEGF-A) as a prognostic and predictive biomarker among men with locally advanced prostate cancer. The analysis was performed using patients enrolled on RTOG 8610, a phase III randomized control trial of radiation therapy alone (Arm 1) versus short-term neoadjuvant and concurrent androgen deprivation and radiation therapy (Arm 2) in men with locally advanced prostate carcinoma. Tissue samples were obtained from the RTOG tissue repository. Hematoxylin and eosin slides were reviewed, and paraffin blocks were immunohistochemically stained for VEGF expression and graded by Intensity score (0-3). Cox or Fine and Gray's proportional hazards models were used. Sufficient pathologic material was available from 103 (23%) of the 456 analyzable patients enrolled in the RTOG 8610 study. There were no statistically significant differences in the pre-treatment characteristics between the patient groups with and without VEGF intensity data. Median follow-up for all surviving patients with VEGF intensity data is 12.2 years. Univariate and multivariate analyses demonstrated no statistically significant correlation between the intensity of VEGF expression and overall survival, distant metastasis, local progression, disease-free survival, or biochemical failure. VEGF expression was also not statistically significantly associated with any of the endpoints when analyzed by treatment arm. This study revealed no statistically significant prognostic or predictive value of VEGF expression for locally advanced prostate cancer. This analysis is among one of the largest sample bases with long-term follow-up in a well-characterized patient population. There is an urgent need to establish multidisciplinary initiatives for coordinating further research in the area of human prostate cancer biomarkers.

Imaging heterogeneity in the mitochondrial redox state of premalignant pancreas in the pancreas-specific PTEN-null transgenic mouse model

PubMed Central

2013-01-01

Background Metabolic alteration is one of the hallmarks of carcinogenesis. We aimed to identify certain metabolic biomarkers for the early detection of pancreatic cancer (PC) using the transgenic PTEN-null mouse model. Pancreas-specific deletion of PTEN in mouse caused progressive premalignant lesions such as highly proliferative ductal metaplasia. We imaged the mitochondrial redox state of the pancreases of the transgenic mice approximately eight months old using the redox scanner, i.e., the nicotinamide adenine dinucleotide/oxidized flavoproteins (NADH/Fp) fluorescence imager at low temperature. Two different approaches, the global averaging of the redox indices without considering tissue heterogeneity along tissue depth and the univariate analysis of multi-section data using tissue depth as a covariate were adopted for the statistical analysis of the multi-section imaging data. The standard deviations of the redox indices and the histogram analysis with Gaussian fit were used to determine the tissue heterogeneity. Results All methods show consistently that the PTEN deficient pancreases (Pdx1-Cre;PTENlox/lox) were significantly more heterogeneous in their mitochondrial redox state compared to the controls (PTENlox/lox). Statistical analysis taking into account the variations of the redox state with tissue depth further shows that PTEN deletion significantly shifted the pancreatic tissue to an overall more oxidized state. Oxidization of the PTEN-null group was not seen when the imaging data were analyzed by global averaging without considering the variation of the redox indices along tissue depth, indicating the importance of taking tissue heterogeneity into account for the statistical analysis of the multi-section imaging data. Conclusions This study reveals a possible link between the mitochondrial redox state alteration of the pancreas and its malignant transformation and may be further developed for establishing potential metabolic biomarkers for the early diagnosis of pancreatic cancer. PMID:24252270

Model-based methods for case definitions from administrative health data: application to rheumatoid arthritis

PubMed Central

Kroeker, Kristine; Widdifield, Jessica; Muthukumarana, Saman; Jiang, Depeng; Lix, Lisa M

2017-01-01

Objective This research proposes a model-based method to facilitate the selection of disease case definitions from validation studies for administrative health data. The method is demonstrated for a rheumatoid arthritis (RA) validation study. Study design and setting Data were from 148 definitions to ascertain cases of RA in hospital, physician and prescription medication administrative data. We considered: (A) separate univariate models for sensitivity and specificity, (B) univariate model for Youden’s summary index and (C) bivariate (ie, joint) mixed-effects model for sensitivity and specificity. Model covariates included the number of diagnoses in physician, hospital and emergency department records, physician diagnosis observation time, duration of time between physician diagnoses and number of RA-related prescription medication records. Results The most common case definition attributes were: 1+ hospital diagnosis (65%), 2+ physician diagnoses (43%), 1+ specialist physician diagnosis (51%) and 2+ years of physician diagnosis observation time (27%). Statistically significant improvements in sensitivity and/or specificity for separate univariate models were associated with (all p values <0.01): 2+ and 3+ physician diagnoses, unlimited physician diagnosis observation time, 1+ specialist physician diagnosis and 1+ RA-related prescription medication records (65+ years only). The bivariate model produced similar results. Youden’s index was associated with these same case definition criteria, except for the length of the physician diagnosis observation time. Conclusion A model-based method provides valuable empirical evidence to aid in selecting a definition(s) for ascertaining diagnosed disease cases from administrative health data. The choice between univariate and bivariate models depends on the goals of the validation study and number of case definitions. PMID:28645978

Multivariate bias adjustment of high-dimensional climate simulations: the Rank Resampling for Distributions and Dependences (R2D2) bias correction

NASA Astrophysics Data System (ADS)

Vrac, Mathieu

2018-06-01

Climate simulations often suffer from statistical biases with respect to observations or reanalyses. It is therefore common to correct (or adjust) those simulations before using them as inputs into impact models. However, most bias correction (BC) methods are univariate and so do not account for the statistical dependences linking the different locations and/or physical variables of interest. In addition, they are often deterministic, and stochasticity is frequently needed to investigate climate uncertainty and to add constrained randomness to climate simulations that do not possess a realistic variability. This study presents a multivariate method of rank resampling for distributions and dependences (R2D2) bias correction allowing one to adjust not only the univariate distributions but also their inter-variable and inter-site dependence structures. Moreover, the proposed R2D2 method provides some stochasticity since it can generate as many multivariate corrected outputs as the number of statistical dimensions (i.e., number of grid cell × number of climate variables) of the simulations to be corrected. It is based on an assumption of stability in time of the dependence structure - making it possible to deal with a high number of statistical dimensions - that lets the climate model drive the temporal properties and their changes in time. R2D2 is applied on temperature and precipitation reanalysis time series with respect to high-resolution reference data over the southeast of France (1506 grid cell). Bivariate, 1506-dimensional and 3012-dimensional versions of R2D2 are tested over a historical period and compared to a univariate BC. How the different BC methods behave in a climate change context is also illustrated with an application to regional climate simulations over the 2071-2100 period. The results indicate that the 1d-BC basically reproduces the climate model multivariate properties, 2d-R2D2 is only satisfying in the inter-variable context, 1506d-R2D2 strongly improves inter-site properties and 3012d-R2D2 is able to account for both. Applications of the proposed R2D2 method to various climate datasets are relevant for many impact studies. The perspectives of improvements are numerous, such as introducing stochasticity in the dependence itself, questioning its stability assumption, and accounting for temporal properties adjustment while including more physics in the adjustment procedures.

Brain shaving: adaptive detection for brain PET data

NASA Astrophysics Data System (ADS)

Grecchi, Elisabetta; Doyle, Orla M.; Bertoldo, Alessandra; Pavese, Nicola; Turkheimer, Federico E.

2014-05-01

The intricacy of brain biology is such that the variation of imaging end-points in health and disease exhibits an unpredictable range of spatial distributions from the extremely localized to the very diffuse. This represents a challenge for the two standard approaches to analysis, the mass univariate and the multivariate that exhibit either strong specificity but not as good sensitivity (the former) or poor specificity and comparatively better sensitivity (the latter). In this work, we develop an analytical methodology for positron emission tomography that operates an extraction (‘shaving’) of coherent patterns of signal variation while maintaining control of the type I error. The methodology operates two rotations on the image data, one local using the wavelet transform and one global using the singular value decomposition. The control of specificity is obtained by using the gap statistic that selects, within each eigenvector, a subset of significantly coherent elements. Face-validity of the algorithm is demonstrated using a paradigmatic data-set with two radiotracers, [11C]-raclopride and [11C]-(R)-PK11195, measured on the same Huntington's disease patients, a disorder with a genetic based diagnosis. The algorithm is able to detect the two well-known separate but connected processes of dopamine neuronal loss (localized in the basal ganglia) and neuroinflammation (diffusive around the whole brain). These processes are at the two extremes of the distributional envelope, one being very sparse and the latter being perfectly Gaussian and they are not adequately detected by the univariate and the multivariate approaches.

Multivariate Radiological-Based Models for the Prediction of Future Knee Pain: Data from the OAI

PubMed Central

Galván-Tejada, Jorge I.; Celaya-Padilla, José M.; Treviño, Victor; Tamez-Peña, José G.

2015-01-01

In this work, the potential of X-ray based multivariate prognostic models to predict the onset of chronic knee pain is presented. Using X-rays quantitative image assessments of joint-space-width (JSW) and paired semiquantitative central X-ray scores from the Osteoarthritis Initiative (OAI), a case-control study is presented. The pain assessments of the right knee at the baseline and the 60-month visits were used to screen for case/control subjects. Scores were analyzed at the time of pain incidence (T-0), the year prior incidence (T-1), and two years before pain incidence (T-2). Multivariate models were created by a cross validated elastic-net regularized generalized linear models feature selection tool. Univariate differences between cases and controls were reported by AUC, C-statistics, and ODDs ratios. Univariate analysis indicated that the medial osteophytes were significantly more prevalent in cases than controls: C-stat 0.62, 0.62, and 0.61, at T-0, T-1, and T-2, respectively. The multivariate JSW models significantly predicted pain: AUC = 0.695, 0.623, and 0.620, at T-0, T-1, and T-2, respectively. Semiquantitative multivariate models predicted paint with C-stat = 0.671, 0.648, and 0.645 at T-0, T-1, and T-2, respectively. Multivariate models derived from plain X-ray radiography assessments may be used to predict subjects that are at risk of developing knee pain. PMID:26504490

Multivariate assessment of event-related potentials with the t-CWT method.

PubMed

Bostanov, Vladimir

2015-11-05

Event-related brain potentials (ERPs) are usually assessed with univariate statistical tests although they are essentially multivariate objects. Brain-computer interface applications are a notable exception to this practice, because they are based on multivariate classification of single-trial ERPs. Multivariate ERP assessment can be facilitated by feature extraction methods. One such method is t-CWT, a mathematical-statistical algorithm based on the continuous wavelet transform (CWT) and Student's t-test. This article begins with a geometric primer on some basic concepts of multivariate statistics as applied to ERP assessment in general and to the t-CWT method in particular. Further, it presents for the first time a detailed, step-by-step, formal mathematical description of the t-CWT algorithm. A new multivariate outlier rejection procedure based on principal component analysis in the frequency domain is presented as an important pre-processing step. The MATLAB and GNU Octave implementation of t-CWT is also made publicly available for the first time as free and open source code. The method is demonstrated on some example ERP data obtained in a passive oddball paradigm. Finally, some conceptually novel applications of the multivariate approach in general and of the t-CWT method in particular are suggested and discussed. Hopefully, the publication of both the t-CWT source code and its underlying mathematical algorithm along with a didactic geometric introduction to some basic concepts of multivariate statistics would make t-CWT more accessible to both users and developers in the field of neuroscience research.

The Relationship between Resettlement and Birth Rates: The Case of Gambella, Ethiopia.

PubMed

Adugna, Aynalem; Kloos, Helmut

2016-07-01

This study aims to examine the possible impacts of resettlement on birth rates by using the length of stay variable in the 2000 Demographic and Health Survey (DHS). Data in all three rounds of Gambella Administrative Region's Demographic and Health Surveys (DHS) are analyzed. The neighboring administrative region of Benishangul-Gumuz is used as a control. The multivariate analysis of variance (MANOVA) is applied with duration of residence as a categorical independent variable. The statistical software SAS is used. In a univariate analysis of Gambella's DHS 2000, duration of residence has a significant effect on mothers' age at first birth (p < 0.001), the number of children born within the five years of the survey (p<0.001), and the total number of children ever born (P<0.001). In the MANOVA analysis, the duration effect on all three is also statistically significant (p<0.001). Resettlement had a disruptive effect on birth rates among females who were just coming into marriageable ages in places of origin but were resettled to Gambella. Although the disruptive effects waned over time, the initial shortfall resulted in reduced overall lifetime births for settler women who were not past the midpoint of their reproductive years at arrival. Based on the reproductive history of female settlers with different duration of residence in the resettlement schemes, we recommend the reinstatement of the length of residence question in future DHS surveys in Ethiopia to allow a longitudinal tracking of demographic trends among nonnative populations.

Potential predictors of risk sexual behavior among private college students in Mekelle City, North Ethiopia.

PubMed

Gebresllasie, Fanna; Tsadik, Mache; Berhane, Eyoel

2017-01-01

Risk sexual practice among students from public universities/colleges is common in Ethiopia. However, little has been known about risk sexual behavior of students in private colleges where more students are potentially enrolled. Therefore, this study aimed to assess the magnitude of risky sexual behaviors and predictors among students of Private Colleges in Mekelle City. A mixed design of both quantitative and qualitative methods was used among 627 randomly selected students of private colleges from February to march 2013. Self administered questionnaire and focus group discussion was used to collect data. A thematic content analysis was used for the qualitative part. For the quantitative study, Univariate, Bivariate and multivariable analysis was made using SPSS version 16 statistical package and p value less than 0.05 was used as cut off point for a statistical significance. Among the total 590 respondents, 151 (29.1%) have ever had sex. Among the sexually active students, 30.5% reported having had multiple sexual partners and consistent condom use was nearly 39%. In multivariable logistic regression analysis, variables such as sex, age group, sex last twelve months and condom use last twelve months was found significantly associated with risky sexual behavior. The findings of qualitative and quantitative study showed consistency in presence of risk factors. Finding of this study showed sexual risk behaviors is high among private colleges such as multiple sexual partners and substance use. So that colleges should emphasis on promoting healthy sexual and reproductive health programs.

Risk factors for repetitive strain injuries among school teachers in Thailand.

PubMed

Chaiklieng, Sunisa; Suggaravetsiri, Pornnapa

2012-01-01

Prolonged posture, static works and repetition are previously reported as the cause of repetitive strain injuries (RSIs) among workers including teachers. This cross-sectional analytic study aimed to investigate the prevalence and risk factors of RSIs among school teachers. Participants were 452 full-time school teachers in Thailand. Data were collected by the structural questionnaires, illuminance measurements and the physical fitness tests. Descriptive statistics and inferential statistics which were Chi-square test and multiple logistic regression analysis were used. Most teachers in this study were females (57.3%), the mean years of work experience was 22.6 ± 10.4 years. The six-month prevalence of RSIs was 73.7%. The univariate analysis identified the related risk factors to RSIs which were chronic disease (OR=1.8; 95% CI = 1.16-2.73), history of trauma (OR=2.0; 95% CI = 1.02-4.01), member of family had RSIs (OR=2.0; 95% CI = 1.02- 4.01), stretch to write on board (OR=1.7; 95% CI = 1.06-1.70) and high heel shoe >2 inch (OR=1.6; 95% CI = 1.03-2.51). Multiple logistic regression analysis showed that chronic diseases and high heel shoe >2 inch significantly related to developing of RSIs. The poor grip strength and back muscle flexibility significantly affected RSIs of teachers. In conclusions, RSIs were highly prevalent in school teachers that they should be aware of health promotion to prevent RSIs.

Human equilibrative nucleoside transporter 1 (hENT1) levels predict response to gemcitabine in patients with biliary tract cancer (BTC).

PubMed

Santini, Daniele; Schiavon, Gaia; Vincenzi, Bruno; Cass, Carol E; Vasile, Enrico; Manazza, Andrea D; Catalano, Vincenzo; Baldi, Giacomo Giulio; Lai, Raymond; Rizzo, Sergio; Giacobino, Alice; Chiusa, Luigi; Caraglia, Michele; Russo, Antonio; Mackey, John; Falcone, Alfredo; Tonini, Giuseppe

2011-01-01

Translational data suggest that nucleoside transporters, in particular human equilibrative nucleoside transporter 1 (hENT1), play an important role in predicting clinical outcome after gemcitabine chemotherapy for several types of cancer. The aim of this study was to retrospectively determine patients' outcome according to the expression of hENT1 in tumoral cells of patients receiving gemcitabine-based therapy. The immunohistochemistry analysis was performed on samples from thirty-one patients with unresectable biliary tract cancer (BTC) consecutively treated with first line gemcitabine-based regimens. Positive hENT1 staining patients were 21 (67.7%); negative hENT1 staining patients were 10 (32.3%). Statistical analysis revealed no association between baseline characteristics, toxicities and tumor response to gemcitabine and hENT1 levels. In the univariate analysis, HENT1 expression was significantly correlated with time to progression (TTP) (p=0.0394; HR 2.902, 95%CI 1.053-7.996). The median TTP was 6.33 versus 2.83 months, respectively in patients with positive versus negative hENT1 staining. Moreover, patients with positive hENT1 expression showed a longer median overall survival when compared with patients with low hENT1 expression (14 versus 7 months, respectively), but this difference did not reach the statistical significance (p=0.128). Therefore, hENT1 may be a relevant predictive marker of benefit from gemcitabine-based therapies in patients with advanced BTC.

[Burnout syndrome in teachers from two universities in Popayán, Colombia].

PubMed

Correa-Correa, Zamanda; Muñoz-Zambrano, Isabel; Chaparro, Andrés F

2010-08-01

Evaluating professional exhaustion or burnout syndrome: background, syndrome and consequences amongst half-time and full-time staff working in two private universities in the city of Popayán during 2008. The study population included 44 male and female participants aged 20 to 40 who were evaluated by using a brief burnout questionnaire (BBQ). This questionnaire had been validated for Latin-American and for teachers. It was not exclusively focused on the structure of the syndrome itself but rather included background elements and consequences. The study was quantitative and cross-sectional, having a deductive hypothetical methodological focus. Descriptive statistics and the Chi-square test were used for data analysis, accepting p<0.05 statistical significance. The analysis was univariate and bivariate. The results indicated low burnout syndrome frequency in the study population. However, 9.1 % high depersonalization frequency was found (i.e. teachers had developed negative attitudes and were insensitive to those receiving their services) and 15.9 % and 9.1 % frequencies for high physical and social consequences, respectively. Bivariate analysis revealed significant association of several factors. The results indicated low burnout syndrome frequency in this population. However, factors which were highly associated with physical and social consequences were: being male, aged 20 to 40, having a marital relationship with a habitual partner, working full-time, working at home and spending more than 75 % of the working day interacting with the beneficiaries of the services being provided.

Multivariate analysis of fMRI time series: classification and regression of brain responses using machine learning.

PubMed

Formisano, Elia; De Martino, Federico; Valente, Giancarlo

2008-09-01

Machine learning and pattern recognition techniques are being increasingly employed in functional magnetic resonance imaging (fMRI) data analysis. By taking into account the full spatial pattern of brain activity measured simultaneously at many locations, these methods allow detecting subtle, non-strictly localized effects that may remain invisible to the conventional analysis with univariate statistical methods. In typical fMRI applications, pattern recognition algorithms "learn" a functional relationship between brain response patterns and a perceptual, cognitive or behavioral state of a subject expressed in terms of a label, which may assume discrete (classification) or continuous (regression) values. This learned functional relationship is then used to predict the unseen labels from a new data set ("brain reading"). In this article, we describe the mathematical foundations of machine learning applications in fMRI. We focus on two methods, support vector machines and relevance vector machines, which are respectively suited for the classification and regression of fMRI patterns. Furthermore, by means of several examples and applications, we illustrate and discuss the methodological challenges of using machine learning algorithms in the context of fMRI data analysis.

Phytochemical diversity of cranberry (Vaccinium macrocarpon Aiton) cultivars by anthocyanin determination and metabolomic profiling with chemometric analysis.

PubMed

Brown, Paula N; Murch, Susan J; Shipley, Paul

2012-01-11

Originally native to the eastern United States, American cranberry ( Vaccinium macrocarpon Aiton, family Ericaceae) cultivation of native and hybrid varieties has spread across North America. Herein is reported the phytochemical diversity of five cranberry cultivars (Stevens, Ben Lear, Bergman, Pilgrim, and GH1) collected in the Greater Vancouver Regional District, by anthocyanin content and UPLC-TOF-MS metabolomic profiling. The anthocyanin content for biological replicates (n = 5) was determined as 7.98 ± 5.83, Ben Lear; 7.02 ± 1.75, Bergman; 6.05 ± 2.51, GH1; 3.28 ± 1.88, Pilgrim; and 2.81 ± 0.81, Stevens. Using subtractive metabonomic algorithms 6481 compounds were found conserved across all varietals, with 136 (Ben Lear), 84 (Bergman), 91 (GH1), 128 (Pilgrim), and 165 (Stevens) unique compounds observed. Principal component analysis (PCA) did not differentiate varieties, whereas partial least-squares discriminate analysis (PLS-DA) exhibited clustering patterns. Univariate statistical approaches were applied to the data set, establishing significance of values and assessing quality of the models. Metabolomic profiling with chemometric analysis proved to be useful for characterizing metabonomic changes across cranberry varieties.

Neutrophil-to-lymphocyte ratio in head and neck cancer.

PubMed

Haddad, Carol R; Guo, Linxin; Clarke, Stephen; Guminski, Alex; Back, Michael; Eade, Thomas

2015-08-01

The neutrophil-to-lymphocyte ratio (NLR) is an index of systemic inflammatory burden in malignancy. An elevated NLR has been associated with poor prognosis in a number of cancer sites. We investigated its role in a cohort of patients with locally advanced head and neck cancer. Eligible patients had primary mucosal squamous cell carcinoma treated with chemoradiotherapy and a minimum follow-up of 12 months (unless deceased). NLR was analysed as <5 vs. ≥5 and above and below the median. The primary endpoint was overall survival (OS) and secondary endpoints metastasis free survival and locoregional relapse free survival. Actuarial Kaplan-Meier statistics and log rank test were used. Univariate analysis for age (continuous), Eastern Cooperative Oncology Group performance status (0 vs. 1), gender (male vs. female), smoking (yes vs. no), American Joint Committee on Cancer stage (III vs. IV) and NLR (<5 vs. ≥5 and <3.3 vs. ≥3.3) were performed. Forty-six patients were included in this analysis. Median NLR was 3.3 (0.4-22.8). After a median follow-up of 34 months (13-47 months), the 2-year estimated OS, metastasis free survival and locoregional relapse free survival for NLR <5 vs. ≥5 were 89% vs. 61% (p = 0.017), 84% vs. 64% (p = 0.083) and 81% vs. 70% (p = 0.17) respectively. On univariate analysis NLR ≥5 (p = 0.025), older age (p = 0.01) and ECOG 1 (p = 0.025) were significant for OS. In this cohort of locally advanced head and neck cancer patients treated with chemoradiotherapy, pre-treatment NLR ≥5 was prognostic for mortality. Further studies are required to confirm these results and to assess the interaction with other prognostic factors. © 2015 The Royal Australian and New Zealand College of Radiologists.

Time from prior chemotherapy enhances prognostic risk grouping in the second-line setting of advanced urothelial carcinoma: a retrospective analysis of pooled, prospective phase 2 trials.

PubMed

Sonpavde, Guru; Pond, Gregory R; Fougeray, Ronan; Choueiri, Toni K; Qu, Angela Q; Vaughn, David J; Niegisch, Guenter; Albers, Peter; James, Nicholas D; Wong, Yu-Ning; Ko, Yoo-Joung; Sridhar, Srikala S; Galsky, Matthew D; Petrylak, Daniel P; Vaishampayan, Ulka N; Khan, Awais; Vogelzang, Nicholas J; Beer, Tomasz M; Stadler, Walter M; O'Donnell, Peter H; Sternberg, Cora N; Rosenberg, Jonathan E; Bellmunt, Joaquim

2013-04-01

Outcomes for patients in the second-line setting of advanced urothelial carcinoma (UC) are dismal. The recognized prognostic factors in this context are Eastern Cooperative Oncology Group (ECOG) performance status (PS) >0, hemoglobin level (Hb) <10 g/dl, and liver metastasis (LM). The purpose of this retrospective study of prospective trials was to investigate the prognostic value of time from prior chemotherapy (TFPC) independent of known prognostic factors. Data from patients from seven prospective trials with available baseline TFPC, Hb, PS, and LM values were used for retrospective analysis (n=570). External validation was conducted in a second-line phase 3 trial comparing best supportive care (BSC) versus vinflunine plus BSC (n=352). Cox proportional hazards regression was used to evaluate the association of factors, with overall survival (OS) and progression-free survival (PFS) being the respective primary and secondary outcome measures. ECOG-PS >0, LM, Hb <10 g/dl, and shorter TFPC were significant prognostic factors for OS and PFS on multivariable analysis. Patients with zero, one, two, and three to four factors demonstrated median OS of 12.2, 6.7, 5.1, and 3.0 mo, respectively (concordance statistic=0.638). Setting of prior chemotherapy (metastatic disease vs perioperative) and prior platinum agent (cisplatin or carboplatin) were not prognostic factors. External validation demonstrated a significant association of TFPC with PFS on univariable and most multivariable analyses, and with OS on univariable analyses. Limitations of retrospective analyses are applicable. Shorter TFPC enhances prognostic classification independent of ECOG-PS >0, Hb <10 g/dl, and LM in the setting of second-line therapy for advanced UC. These data may facilitate drug development and interpretation of trials. Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Metastasis in dedifferentiated liposarcoma: Predictors and outcome in 148 patients.

PubMed

Tirumani, S H; Tirumani, H; Jagannathan, J P; Shinagare, A B; Hornick, J L; Ramaiya, N H; Wagner, A J

2015-07-01

To describe the pattern of dedifferentiated liposarcoma (DDLPS) metastases and to analyze their predictors and outcome. In this retrospective study, we reviewed the imaging and clinical records of all consenting patients with histopathology-confirmed DDLPS seen from 2000 through 2012. The predictive value of clinical and histopathologic parameters for metastasis later in the disease course was analyzed using univariate and multivariate analyses. Survival of patients with and without metastasis was compared using Log-rank test. Records of 148 patients (57 women, 91 men; mean age 59 years, range 30-87 years) were reviewed. Distant metastases were observed in 44/148 patients (29.7%), 9/44 (20.5%) at presentation and 35/44 (79.5%) developing them later at a median interval of 8 months (IQR = 0.80-26 months). Median duration of follow-up was 38 months (IQR = 18-74 months) with 77/148 patients (31 with metastases) deceased at the time of analysis. Median survival was 28 months (IQR = 10-56 months) for patients with metastases and 38 months (IQR, 17-65 months) for patients without metastases (p = 0.0123, Log-Rank test; Hazard ratio 1.79 [95% confidence interval 1.11-2.84]). Lung was the most common site of metastases (33 patients, 22.3%). On univariate analysis, grade and local recurrence were associated with subsequent risk of metastasis where as age, tumor size, site, de novo dedifferentiation, number of previous surgical resections, margin positivity and chemoradiation were not. On multivariate analysis, high tumor grade (p-value = 0.0005, OR 5.05; 95% CI 2.01-13.48) and local recurrence (p-value = 0.0025, OR 4.46; 95% CI 1.67-13.40) predicted metastasis. Lung was most frequent site of DDLPS metastases. Risk of developing metastatic disease was statistically associated with tumor grade and local recurrence. Metastatic disease was associated with decreased survival. Copyright © 2015 Elsevier Ltd. All rights reserved.

Predictive factors for the severity of liver fibrosis in patients with chronic hepatitis C and moderate alcohol consumption.

PubMed

Vădan, Roxana; Gheorghe, Liana; Becheanu, Gabriel; Iacob, Răzvan; Iacob, Speranţa; Gheorghe, Cristian

2003-09-01

Among the histological lesions seen in chronic hepatitis C (CHC), the presence of steatosis, bile duct lesions and lymphoid aggregates are characteristic. Recent reports suggest that steatosis is an independent risk factor for liver fibrosis in CHC. The aim of our study was to determine the relative contribution of steatosis and moderate alcohol consumption to the severity of liver fibrosis in patients infected with genotype 1 hepatitis C virus. We evaluated the patients with biopsy proven CHC and no or only moderate alcohol intake (<40 g/day). The demographical parameters of the study population, the indices of alcohol consumption: erythrocyte median corpuscular volume (MCV), gamma-glutamyl transpeptidase (GGT), the histological characteristics were noted and a statistical analysis was performed in order to determine the factors independently associated with severe fibrosis and with severe steatosis. From the 200 patients included in the study, 82 were males and 118 females, with a mean age of 47.75+/-10.42 years. At univariate analysis, advanced (grade 2, 3) fibrosis correlated with: the age at the time of biopsy, increased inflammatory activity (HAI), moderate/severe steatosis, alcohol intake, elevated GGT and MCV values. After multivariate logistic regression only age, HAI and steatosis were independently associated with advanced fibrosis stage. Regarding hepatic steatosis, from the factors found to correlate with severe steatosis at univariate analysis (alcohol intake, elevated GGT and MCV levels, severe fibrosis), after multivariate logistic regression only the elevated level of GGT was an independent prognostic factor for severe steatosis. Steatosis is an important risk factor for the severity of liver disease in CHC patients. Among patients with genotype 1 hepatitis C virus infection and moderate alcohol intake, those with serum levels of GGT over two times the normal value are at high risk for severe steatosis.

Predictive factors for survival and correlation to toxicity in advanced Stage III non-small cell lung cancer patients with concurrent chemoradiation.

PubMed

Kim, Yong-Hyub; Ahn, Sung-Ja; Kim, Young-Chul; Kim, Kyu-Sik; Oh, In-Jae; Ban, Hee-Jung; Chung, Woong-Ki; Nam, Taek-Keun; Yoon, Mee Sun; Jeong, Jae-Uk; Song, Ju-Young

2016-02-01

Concurrent chemoradiotherapy is the standard treatment for locally advanced Stage III non-small cell lung cancer in patients with a good performance status and minimal weight loss. This study aimed to define subgroups with different survival outcomes and identify correlations with the radiation-related toxicities. We retrospectively reviewed 381 locally advanced Stage III non-small cell lung cancer patients with a good performance status or weight loss of <10% who received concurrent chemoradiotherapy between 2004 and 2011. Three-dimensional conformal radiotherapy was administered once daily, combined with weekly chemotherapy. The Kaplan-Meier method was used for survival comparison and Cox regression for multivariate analysis. Multivariate analysis was performed using all variables with P values <0.1 from the univariate analysis. Median survival of all patients was 24 months. Age > 75 years, the diffusion lung capacity for carbon monoxide ≤80%, gross tumor volume ≥100 cm(3) and subcarinal nodal involvement were the statistically significant predictive factors for poor overall survival both in univariate and multivariate analyses. Patients were classified into four groups according to these four predictive factors. The median survival times were 36, 29, 18 and 14 months in Groups I, II, III and IV, respectively (P < 0.001). Rates of esophageal or lung toxicity ≥Grade 3 were 5.9, 14.1, 12.5 and 22.2%, respectively. The radiotherapy interruption rate differed significantly between the prognostic subgroups; 8.8, 15.4, 22.7 and 30.6%, respectively (P = 0.017). Severe toxicity and interruption of radiotherapy were more frequent in patients with multiple adverse predictive factors. To maintain the survival benefit in patients with concurrent chemoradiotherapy, strategies to reduce treatment-related toxicities need to be deeply considered. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiotherapy is associated with significant improvement in local and regional control in Merkel cell carcinoma

PubMed Central

2012-01-01

Introduction Merkel cell carcinoma (MCC) is a rare tumour of skin. This study is a retrospective audit of patients with MCC from St Vincent’s and Mater Hospital, Sydney, Australia. The aim of this study was to investigate the influence of radiotherapy (RT) on the local and regional control of MCC lesions and survival of patients with MCC. Method The data bases in anatomical pathology, RT and surgery. We searched for patients having a diagnosis of MCC between 1996 and 2007. Patient, tumour and treatment characteristics were collected and analysed. Univariate survival analysis of categorical variables was conducted with the Kaplan-Meier method together with the Log-Rank test for statistical significance. Continuous variables were assessed using the Cox regression method. Multivariate analysis was performed for significant univariate results. Results Sixty seven patients were found. Sixty two who were stage I-III and were treated with radical intent were analysed. 68% were male. The median age was 74 years. Forty-two cases (68%) were stage I or II, and 20 cases (32%) were stage III. For the subset of 42 stage I and II patients, those that had RT to their primary site had a 2-year local recurrence free survival of 89% compared with 36% for patients not receiving RT (p<0.001). The cumulative 2-year regional recurrence free survival for patients having adjuvant regional RT was 84% compared with 43% for patients not receiving this treatment (p<0.001). Immune status at initial surgery was a significant predictor for OS and MCCSS. In a multivariate analysis combining macroscopic size (mm) and immune status at initial surgery, only immune status remained a significant predictor of overall survival (HR=2.096, 95% CI: 1.002-4.385, p=0.049). Conclusions RT is associated with significant improvement in local and regional control in Merkel cell carcinoma. Immunosuppression is an important factor in overall survival. PMID:23075308

Reliability Implications in Wood Systems of a Bivariate Gaussian-Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull

Treesearch

Steve P. Verrill; James W. Evans; David E. Kretschmann; Cherilyn A. Hatfield

2014-01-01

Two important wood properties are the modulus of elasticity (MOE) and the modulus of rupture (MOR). In the past, the statistical distribution of the MOE has often been modeled as Gaussian, and that of the MOR as lognormal or as a two- or three-parameter Weibull distribution. It is well known that MOE and MOR are positively correlated. To model the simultaneous behavior...

Evaluation of 2 whole-brain radiotherapy schedules and prognostic factors for brain metastases in breast cancer patients.

PubMed

Rades, Dirk; Lohynska, Radka; Veninga, Theo; Stalpers, Lukas J A; Schild, Steven E

2007-12-01

The majority of breast cancer patients with brain metastases receive whole-brain radiotherapy (WBRT) and have a survival of only a few months. A short WBRT regimen would be preferable if it provides survival that is similar to that achieved with longer programs. This retrospective study compared survival and local control within the brain resulting from short-course WBRT with longer programs in 207 breast cancer patients. Sixty-nine patients treated with 5 fractions of 4 grays (Gy) each given within 5 days were compared with 138 patients treated with 10 fractions of 3 Gy each given over 2 weeks or 20 fractions of 2 Gy each given over 4 weeks. Six additional potential prognostic factors were investigated: age, Karnofsky performance score (KPS), number of brain metastases, the presence of extracranial metastases, interval from tumor diagnosis to WBRT, and recursive partitioning analysis (RPA) class. On univariate analysis, the WBRT regimen was not found to be associated with survival (P=.254) or local control (P=.397). Improved survival was associated with a KPS>70 (P<.001), single brain metastasis (P=.023), the absence of extracranial metastases (P<.001), and lower RPA class (P<.001). On multivariate analysis, which was performed without RPA class because this is a confounding variable, KPS (relative risk [RR] of 4.00; P<.001) and the presence of extracranial metastases (RR of 1.54; P=.024) maintained statistical significance. On univariate analysis, local control was associated with KPS (P<.001) and RPA class (P<.001). On multivariate analysis, local control was found to be associated with a KPS>70 (RR of 5.75; P<.001). Short-course WBRT with 5 fractions of 4 Gy each resulted in survival and local control that were similar to longer programs in breast cancer patients with brain metastases. The dose of 5 fractions of 4 Gy each appears preferable for the majority of these patients because it is less time consuming and more convenient. Copyright (c) 2007 American Cancer Society.

Male gender and renal dysfunction are predictors of adverse outcome in nonpostoperative ischemic colitis patients.

PubMed

Lee, Tsung-Chun; Wang, Hsiu-Po; Chiu, Han-Mo; Lien, Wan-Ching; Chen, Mei-Jyh; Yu, Linda C H; Sun, Chia-Tung; Lin, Jaw-Town; Wu, Ming-Shiang

2010-01-01

Ischemic colitis (IC) spans a broad spectrum from self-limiting illness to intestinal gangrene and mortality. Prognostic factors specifically for nonpostoperative IC were not fully characterized. We aim to focus on nonpostoperative IC in patients with renal dysfunction and try to identify prognostic factors for adverse outcomes. We conducted a retrospective analysis at a university-affiliated tertiary medical center in Taiwan. From January 2003 to August 2008, 25 men and 52 women (mean age: 66 y) had colonoscopic biopsy-proven IC without prior culprit surgery. We estimated glomerular filtration rate with simplified Modification of Diet in Renal Disease equation. Nine patients with glomerular filtration rate below 30 mL per minute per 1.73 m were classified as renal dysfunction group (including 7 dialysis patients). Adverse outcomes were defined as need for surgery and mortality. Predictors for adverse outcomes were captured by univariate and multivariate analysis. Research ethical committee approved the study protocol. Patients with renal dysfunction more often had: diabetes mellitus (56% vs. 16%, P=0.02), prolonged symptoms (6.8 d vs. 3.5 d, P=0.01), lower hemoglobin (11.1 g/dL vs. 13.4 g/dL, P=0.01), and more often right colonic involvement (56% vs. 19%, P=0.03). Renal dysfunction patients also had longer hospitalization days (median 15 d vs. 4 d, P=0.045). However, there was no statistical significance in the rate of either surgery or mortality between these 2 groups (P>0.05). Univariate analysis showed that renal dysfunction, sex, emergency department referral, presentation with abdominal pain were significant for adverse outcome (P<0.1). Multivariate analysis revealed that male sex conveyed 9.5-fold risk (P=0.01) and renal dysfunction conveyed 8.5-fold risk (P=0.03) for adverse outcomes. Nonpostoperative IC patients with concurrent renal dysfunction had distinct clinical profiles. Multivariate analysis showed that male patients had 9.5-fold and renal dysfunction patients had 8.5-fold increased risk for adverse outcomes. Although IC is often self-limited, our data warrants special attention and aggressive therapy in treating these patients.

Quantitative Analysis of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography Identifies Novel Prognostic Imaging Biomarkers in Locally Advanced Pancreatic Cancer Patients Treated With Stereotactic Body Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Yi; Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo; Song, Jie

Purpose: To identify prognostic biomarkers in pancreatic cancer using high-throughput quantitative image analysis. Methods and Materials: In this institutional review board–approved study, we retrospectively analyzed images and outcomes for 139 locally advanced pancreatic cancer patients treated with stereotactic body radiation therapy (SBRT). The overall population was split into a training cohort (n=90) and a validation cohort (n=49) according to the time of treatment. We extracted quantitative imaging characteristics from pre-SBRT {sup 18}F-fluorodeoxyglucose positron emission tomography, including statistical, morphologic, and texture features. A Cox proportional hazard regression model was built to predict overall survival (OS) in the training cohort using 162more » robust image features. To avoid over-fitting, we applied the elastic net to obtain a sparse set of image features, whose linear combination constitutes a prognostic imaging signature. Univariate and multivariate Cox regression analyses were used to evaluate the association with OS, and concordance index (CI) was used to evaluate the survival prediction accuracy. Results: The prognostic imaging signature included 7 features characterizing different tumor phenotypes, including shape, intensity, and texture. On the validation cohort, univariate analysis showed that this prognostic signature was significantly associated with OS (P=.002, hazard ratio 2.74), which improved upon conventional imaging predictors including tumor volume, maximum standardized uptake value, and total legion glycolysis (P=.018-.028, hazard ratio 1.51-1.57). On multivariate analysis, the proposed signature was the only significant prognostic index (P=.037, hazard ratio 3.72) when adjusted for conventional imaging and clinical factors (P=.123-.870, hazard ratio 0.53-1.30). In terms of CI, the proposed signature scored 0.66 and was significantly better than competing prognostic indices (CI 0.48-0.64, Wilcoxon rank sum test P<1e-6). Conclusion: Quantitative analysis identified novel {sup 18}F-fluorodeoxyglucose positron emission tomography image features that showed improved prognostic value over conventional imaging metrics. If validated in large, prospective cohorts, the new prognostic signature might be used to identify patients for individualized risk-adaptive therapy.« less

Evaluation of risk factors for perforated peptic ulcer.

PubMed

Yamamoto, Kazuki; Takahashi, Osamu; Arioka, Hiroko; Kobayashi, Daiki

2018-02-15

The aim of this study was to evaluate the prediction factors for perforated peptic ulcer (PPU). At St. Luke's International Hospital in Tokyo, Japan, a case control study was performed between August 2004 and March 2016. All patients diagnosed with PPU were included. As control subjects, patients with age, sex and date of CT scan corresponding to those of the PPU subjects were included in the study at a proportion of 2 controls for every PPU subject. All data such as past medical histories, physical findings, and laboratory data were collected through chart reviews. Univariate analyses and multivariate analyses with logistic regression were conducted, and receiver operating characteristic curves (ROCs) were calculated to show validity. Sensitivity analyses were performed to confirm results using a stepwise method and conditional logistic regression. A total of 408 patients were included in this study; 136 were a group of patients with PPU, and 272 were a control group. Univariate analysis showed statistical significance in many categories. Four different models of multivariate analyses were conducted, and significant differences were found for muscular defense and a history of peptic ulcer disease (PUD) in all models. The conditional forced-entry analysis of muscular defense showed an odds ratio (OR) of 23.8 (95% confidence interval [CI]: 5.70-100.0), and the analysis of PUD history showed an OR of 6.40 (95% CI: 1.13-36.2). The sensitivity analysis showed consistent results, with an OR of 23.8-366.2 for muscular defense and an OR of 3.67-7.81 for PUD history. The area under the curve (AUC) of all models was high enough to confirm the results. However, anticoagulants, known risk factors for PUD, did not increase the risk for PPU in our study. The conditional forced-entry analysis of anticoagulant use showed an OR of 0.85 (95% CI: 0.03-22.3). The evaluation of prediction factors and development of a prediction rule for PPU may help our decision making in performing a CT scan for patients with acute abdominal pain.

CD147 as a novel biomarker for predicting the prognosis and clinicopathological features of bladder cancer: a meta-analysis

PubMed Central

Li, Hongru; Xu, Yadong; Li, Hui

2017-01-01

Objective To assess the prognostic and clinicopathological characteristics of CD147 in human bladder cancer. Methods Studies on CD147 expression in bladder cancer were retrieved from PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, and the WanFang databases. Outcomes were pooled with meta-analyzing softwares RevMan 5.3 and STATA 14.0. Results Twenty-four studies with 25 datasets demonstrated that CD147 expression was higher in bladder cancer than in non-cancer tissues (OR=43.64, P<0.00001). Moreover, this increase was associated with more advanced clinical stages (OR=73.89, P<0.0001), deeper invasion (OR=3.22, P<0.00001), lower histological differentiation (OR=4.54, P=0.0005), poorer overall survival (univariate analysis, HR=2.63, P<0.00001; multivariate analysis, HR=1.86, P=0.00036), disease specific survival (univariate analysis, HR=1.65, P=0.002), disease recurrence-free survival (univariate analysis, HR=2.78, P=0.001; multivariate analysis, HR=5.51, P=0.017), rate of recurrence (OR=1.91, P=0.0006), invasive depth (pT2∼T4 vs. pTa∼T1; OR=3.22, P<0.00001), and histological differentiation (low versus moderate-to-high; OR=4.54, P=0.0005). No difference was found among disease specific survival in multivariate analysis (P=0.067), lymph node metastasis (P=0.12), and sex (P=0.15). Conclusion CD147 could be a biomarker for early diagnosis, treatment, and prognosis of bladder cancer. PMID:28977970

Measures of dependence for multivariate Lévy distributions

NASA Astrophysics Data System (ADS)

Boland, J.; Hurd, T. R.; Pivato, M.; Seco, L.

2001-02-01

Recent statistical analysis of a number of financial databases is summarized. Increasing agreement is found that logarithmic equity returns show a certain type of asymptotic behavior of the largest events, namely that the probability density functions have power law tails with an exponent α≈3.0. This behavior does not vary much over different stock exchanges or over time, despite large variations in trading environments. The present paper proposes a class of multivariate distributions which generalizes the observed qualities of univariate time series. A new consequence of the proposed class is the "spectral measure" which completely characterizes the multivariate dependences of the extreme tails of the distribution. This measure on the unit sphere in M-dimensions, in principle completely general, can be determined empirically by looking at extreme events. If it can be observed and determined, it will prove to be of importance for scenario generation in portfolio risk management.

[Does self-esteem affect body dissatisfaction levels in female adolescents?].

PubMed

Fortes, Leonardo de Sousa; Cipriani, Flávia Marcele; Coelho, Fernanda Dias; Paes, Santiago Tavares; Ferreira, Maria Elisa Caputo

2014-09-01

To evaluate the influence of self-esteem on levels of body dissatisfaction among adolescent females. A group of 397 adolescents aged 12 to 17 years were enrolled in the study. The Body Shape Questionnaire (BSQ) was applied to assess body dissatisfaction. The Rosenberg Self-Esteem Scale was used to assess self-esteem. Weight, height, and skinfold thickness were also measured. These anthropometric data were controlled in the statistical analyses. The multiple regression model indicated influence of "positive self-esteem" (R(2)=0.16; p=0.001) and "negative self-esteem" (R(2)=0.23; p=0.001) subscales on the BSQ scores. Univariate analysis of covariance demonstrated differences in BSQ scores (p=0.001) according to groups of self-esteem. It was concluded that self-esteem influenced body dissatisfaction in adolescent girls from Juiz de Fora, MG. Copyright © 2014 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

Correlates of condom use among female prostitutes and tourist clients in Bali, Indonesia.

PubMed

Thorpe, L; Ford, K; Fajans, P; Wirawan, D N

1997-04-01

This study examines the commercial sex activity of both tourist client and local prostitute groups in the host country of Indonesia. The study provides a profile of social and behavioural characteristics of foreign tourist men and Indonesian women engaging in commercial sex, using cross-sectional data gathered in the tourist resort town of Kuta, Bali. Univariate statistical analysis and multiple logistic regression are used to assess psychosocial and other factors associated with consistent condom use in commercial sex encounters, drawing from the Health Belief model and social cognitive theory. Results from both respondent groups indicate that condom use is high between tourist clients and female Indonesian sex workers, although not 100% consistent. Beliefs about condom efficacy and effects on pleasure, as well as susceptibility to STD infection were related to condom use for female sex workers. Beliefs about condoms being too much trouble, and self-efficacy were related to condom use for tourist clients.

The characteristics of soil and water loss in Pinus Massoniana forest in Quaternary red soil area of south China

NASA Astrophysics Data System (ADS)

Song, Yuejun; Huang, Yanhe; Jie, Yang

2017-08-01

The soil and water loss in Pinus massoniana forests is an urgent environmental problem in the red soil region of southern China.Using the method of field monitoring, by analogy and statistical analysis, The characteristics of soil and water loss of Pinus massoniana forests in Quaternary red soil region under 30 rainfall were analyzed,the results show that the relationship models of rainfall,runoff and sediment of pure Pinus massoniana plot were slightly different from the naked control plot,were all the univariate quadratic linear regression models.the contribution of runoff and sediment in different rain types were different, and the water and soil loss in Pinus massoniana forest was most prominent under moderate rain.The merging effect of sparse Pinus massoniana forest on raindrop, aggravated the degree of soil and water loss to some extent.

Photogrammetry: An available surface characterization tool for solar concentrators. Part 2: Assessment of surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shortis, M.; Johnston, G.

1997-11-01

In a previous paper, the results of photogrammetric measurements of a number of paraboloidal reflecting surfaces were presented. These results showed that photogrammetry can provide three-dimensional surface characterizations of such solar concentrators. The present paper describes the assessment of the quality of these surfaces as a derivation of the photogrammetrically produced surface coordinates. Statistical analysis of the z-coordinate distribution of errors indicates that these generally conform to a univariate Gaussian distribution, while the numerical assessment of the surface normal vectors on these surfaces indicates that the surface normal deviations appear to follow an approximately bivariate Gaussian distribution. Ray tracing ofmore » the measured surfaces to predict the expected flux distribution at the focal point of the 400 m{sup 2} dish show a close correlation with the videographically measured flux distribution at the focal point of the dish.« less

Does self-esteem affect body dissatisfaction levels in female adolescents?☆

PubMed Central

Fortes, Leonardo de Sousa; Cipriani, Flávia Marcele; Coelho, Fernanda Dias; Paes, Santiago Tavares; Ferreira, Maria Elisa Caputo

2014-01-01

Objective: To evaluate the influence of self-esteem on levels of body dissatisfaction among adolescent females. Methods: A group of 397 adolescents aged 12 to 17 years were enrolled in the study. The Body Shape Questionnaire (BSQ) was applied to assess body dissatisfaction. The Rosenberg Self-Esteem Scale was used to assess self-esteem. Weight, height, and skinfold thickness were also measured. These anthropometric data were controlled in the statistical analyses. Results: The multiple regression model indicated influence of "positive self-esteem" (R2=0.16; p=0.001) and "negative self-esteem" (R2=0.23; p=0.001) subscales on the BSQ scores. Univariate analysis of covariance demonstrated differences in BSQ scores (p=0.001) according to groups of self-esteem. Conclusion: It was concluded that self-esteem influenced body dissatisfaction in adolescent girls from Juiz de Fora, MG. PMID:25479855

Prognostic significance of blood coagulation tests in carcinoma of the lung and colon.

PubMed

Wojtukiewicz, M Z; Zacharski, L R; Moritz, T E; Hur, K; Edwards, R L; Rickles, F R

1992-08-01

Blood coagulation test results were collected prospectively in patients with previously untreated, advanced lung or colon cancer who entered into a clinical trial. In patients with colon cancer, reduced survival was associated (in univariate analysis) with higher values obtained at entry to the study for fibrinogen, fibrin(ogen) split products, antiplasmin, and fibrinopeptide A and accelerated euglobulin lysis times. In patients with non-small cell lung cancer, reduced survival was associated (in univariate analysis) with higher fibrinogen and fibrin(ogen) split products, platelet counts and activated partial thromboplastin times. In patients with small cell carcinoma of the lung, only higher activated partial thromboplastin times were associated (in univariate analysis) with reduced survival in patients with disseminated disease. In multivariate analysis, higher activated partial thromboplastin times were a significant independent predictor of survival for patients with non-small cell lung cancer limited to one hemithorax and with disseminated small cell carcinoma of the lung. Fibrin(ogen) split product levels were an independent predictor of survival for patients with disseminated non-small cell lung cancer as were both the fibrinogen and fibrinopeptide A levels for patients with disseminated colon cancer. These results suggest that certain tests of blood coagulation may be indicative of prognosis in lung and colon cancer. The heterogeneity of these results suggests that the mechanism(s), intensity, and pathophysiological significance of coagulation activation in cancer may differ between tumour types.

Factors Associated with Salmonella Prevalence in U.S. Swine Grower-Finisher Operations, 2012.

PubMed

Bjork, Kathe E; Fields, Victoria; Garber, Lindsey P; Kopral, Christine A

2018-05-15

Nontyphoidal Salmonella is an important foodborne pathogen with diverse serotypes occurring in animal and human populations. The prevalence of the organism on swine farms has been associated with numerous risk factors, and although there are strong veterinary public health controls for preventing Salmonella from entering food, there remains interest in eradicating or controlling the organism in the preharvest environment. In this study, using data collected via the U.S. Department of Agriculture (USDA) National Animal Health Monitoring System Swine 2012 study, we describe nontyphoidal Salmonella and specific serotype prevalence on U.S. grower-finisher swine operations and investigate associations between Salmonella detection and numerous factors via multiple correspondence analysis (MCA) and regression analysis. MCA plots, complementary to univariate analyses, display relationships between covariates and Salmonella detection at the farm level. In the univariate analysis, Salmonella detection varied with feed characteristics and farm management practices, reports of diseases on farms and vaccinations administered, and administration of certain antimicrobials. Results from the univariate analysis reinforce the importance of biosecurity in managing diseases and pathogens such as Salmonella on farms. All multivariable regression models for the likelihood of Salmonella detection were strongly affected by multicollinearity among variables, and only one variable, pelleted feed preparation, remained in the final model. The study was limited by its cross-sectional nature, timelines of data collection, and reliance on operator-reported data via a convenience sample.

Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions from at-line laboratory to in-line industrial scale.

PubMed

Brouckaert, D; Uyttersprot, J-S; Broeckx, W; De Beer, T

2018-03-01

Calibration transfer or standardisation aims at creating a uniform spectral response on different spectroscopic instruments or under varying conditions, without requiring a full recalibration for each situation. In the current study, this strategy is applied to construct at-line multivariate calibration models and consequently employ them in-line in a continuous industrial production line, using the same spectrometer. Firstly, quantitative multivariate models are constructed at-line at laboratory scale for predicting the concentration of two main ingredients in hard surface cleaners. By regressing the Raman spectra of a set of small-scale calibration samples against their reference concentration values, partial least squares (PLS) models are developed to quantify the surfactant levels in the liquid detergent compositions under investigation. After evaluating the models performance with a set of independent validation samples, a univariate slope/bias correction is applied in view of transporting these at-line calibration models to an in-line manufacturing set-up. This standardisation technique allows a fast and easy transfer of the PLS regression models, by simply correcting the model predictions on the in-line set-up, without adjusting anything to the original multivariate calibration models. An extensive statistical analysis is performed in order to assess the predictive quality of the transferred regression models. Before and after transfer, the R 2 and RMSEP of both models is compared for evaluating if their magnitude is similar. T-tests are then performed to investigate whether the slope and intercept of the transferred regression line are not statistically different from 1 and 0, respectively. Furthermore, it is inspected whether no significant bias can be noted. F-tests are executed as well, for assessing the linearity of the transfer regression line and for investigating the statistical coincidence of the transfer and validation regression line. Finally, a paired t-test is performed to compare the original at-line model to the slope/bias corrected in-line model, using interval hypotheses. It is shown that the calibration models of Surfactant 1 and Surfactant 2 yield satisfactory in-line predictions after slope/bias correction. While Surfactant 1 passes seven out of eight statistical tests, the recommended validation parameters are 100% successful for Surfactant 2. It is hence concluded that the proposed strategy for transferring at-line calibration models to an in-line industrial environment via a univariate slope/bias correction of the predicted values offers a successful standardisation approach. Copyright © 2017 Elsevier B.V. All rights reserved.

History and physical examination findings predictive of testicular torsion: an attempt to promote clinical diagnosis by house staff.

PubMed

Srinivasan, Arun; Cinman, Nadya; Feber, Kevin M; Gitlin, Jordan; Palmer, Lane S

2011-08-01

To standardize the history and physical examination of boys who present with acute scrotum and identify parameters that best predict testicular torsion. Over a 5-month period, a standardized history and physical examination form with 22 items was used for all boys presenting with scrotal pain. Management decisions for radiological evaluation and surgical intervention were based on the results. Data were statistically analyzed in correlation with the eventual diagnosis. Of the 79 boys evaluated, 8 (10.1%) had testicular torsion. On univariate analysis, age, worsening pain, nausea/vomiting, severe pain at rest, absence of ipsilateral cremaster reflex, abnormal testicular position and scrotal skin changes were statistically predictive of torsion. After multivariate analysis and adjusting for confounding effect of other co-existing variables, absence of ipsilateral cremaster reflex (P < 0.001), nausea/vomiting (P < 0.05) and scrotal skin changes (P < 0.001) were the only consistent predictive factors of testicular torsion. An accurate history and physical examination of boys with acute scrotum should be primary in deciding upon further radiographic or surgical evaluation. While several forces have led to less consistent overnight resident staffing, consistent and reliable clinical evaluation of the acute scrotum using a standardized approach should reduce error, improve patient care and potentially reduce health care costs. Copyright © 2011 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Risk factors for early post-operative neurological deterioration in dogs undergoing a cervical dorsal laminectomy or hemilaminectomy: 100 cases (2002-2014).

PubMed

Taylor-Brown, F E; Cardy, T J A; Liebel, F X; Garosi, L; Kenny, P J; Volk, H A; De Decker, S

2015-12-01

Early post-operative neurological deterioration is a well-known complication following dorsal cervical laminectomies and hemilaminectomies in dogs. This study aimed to evaluate potential risk factors for early post-operative neurological deterioration following these surgical procedures. Medical records of 100 dogs that had undergone a cervical dorsal laminectomy or hemilaminectomy between 2002 and 2014 were assessed retrospectively. Assessed variables included signalment, bodyweight, duration of clinical signs, neurological status before surgery, diagnosis, surgical site, type and extent of surgery and duration of procedure. Outcome measures were neurological status immediately following surgery and duration of hospitalisation. Univariate statistical analysis was performed to identify variables to be included in a multivariate model. Diagnoses included osseous associated cervical spondylomyelopathy (OACSM; n = 41), acute intervertebral disk extrusion (IVDE; 31), meningioma (11), spinal arachnoid diverticulum (10) and vertebral arch anomalies (7). Overall 54% (95% CI 45.25-64.75) of dogs were neurologically worse 48 h post-operatively. Multivariate statistical analysis identified four factors significantly related to early post-operative neurological outcome. Diagnoses of OACSM or meningioma were considered the strongest variables to predict early post-operative neurological deterioration, followed by higher (more severely affected) neurological grade before surgery and longer surgery time. This information can aid in the management of expectations of clinical staff and owners with dogs undergoing these surgical procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

A generalized association test based on U statistics.

PubMed

Wei, Changshuai; Lu, Qing

2017-07-01

Second generation sequencing technologies are being increasingly used for genetic association studies, where the main research interest is to identify sets of genetic variants that contribute to various phenotypes. The phenotype can be univariate disease status, multivariate responses and even high-dimensional outcomes. Considering the genotype and phenotype as two complex objects, this also poses a general statistical problem of testing association between complex objects. We here proposed a similarity-based test, generalized similarity U (GSU), that can test the association between complex objects. We first studied the theoretical properties of the test in a general setting and then focused on the application of the test to sequencing association studies. Based on theoretical analysis, we proposed to use Laplacian Kernel-based similarity for GSU to boost power and enhance robustness. Through simulation, we found that GSU did have advantages over existing methods in terms of power and robustness. We further performed a whole genome sequencing (WGS) scan for Alzherimer's disease neuroimaging initiative data, identifying three genes, APOE , APOC1 and TOMM40 , associated with imaging phenotype. We developed a C ++ package for analysis of WGS data using GSU. The source codes can be downloaded at https://github.com/changshuaiwei/gsu . weichangshuai@gmail.com ; qlu@epi.msu.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Meta-analysis in Stata using gllamm.

PubMed

Bagos, Pantelis G

2015-12-01

There are several user-written programs for performing meta-analysis in Stata (Stata Statistical Software: College Station, TX: Stata Corp LP). These include metan, metareg, mvmeta, and glst. However, there are several cases for which these programs do not suffice. For instance, there is no software for performing univariate meta-analysis with correlated estimates, for multilevel or hierarchical meta-analysis, or for meta-analysis of longitudinal data. In this work, we show with practical applications that many disparate models, including but not limited to the ones mentioned earlier, can be fitted using gllamm. The software is very versatile and can handle a wide variety of models with applications in a wide range of disciplines. The method presented here takes advantage of these modeling capabilities and makes use of appropriate transformations, based on the Cholesky decomposition of the inverse of the covariance matrix, known as generalized least squares, in order to handle correlated data. The models described earlier can be thought of as special instances of a general linear mixed-model formulation, but to the author's knowledge, a general exposition in order to incorporate all the available models for meta-analysis as special cases and the instructions to fit them in Stata has not been presented so far. Source code is available at http:www.compgen.org/tools/gllamm. Copyright © 2015 John Wiley & Sons, Ltd.

Nurse executive transformational leadership and organizational commitment.

PubMed

Leach, Linda Searle

2005-05-01

To investigate the relationship between nurse executive leadership and organizational commitment among nurses in acute care hospitals. A key challenge for organizations is to maximize the contributions of all workers by cultivating their commitment. Nurse leaders are in a position to influence organizational commitment among nurses. The theoretical constructs underlying this study are the transformational leadership theory and the Etzioni's organizational theory. A cross-sectional, field survey of nurse executives, nurse managers, and staff nurses was conducted to assess nurse executive transformational and transactional leadership and their relationship to organizational commitment. Hypotheses were tested using correlational analysis, and univariate statistics were used to describe the sample. An inverse relationship between nurse executive transformational and transactional leadership and alienative (highly negative) organizational commitment was statistically significant. A positive association was demonstrated between nurse executive leadership and nurse manager leadership. This study supports the effect of nurse executive leadership on nurse manager leadership and on organizational commitment among nurses despite role distance. To the extent that transformational leadership is present, alienative organizational commitment is reduced. This relationship shows the importance of nurse executive leadership in organizational involvement among nurses in the dynamic context of contemporary hospital settings.

Ecological effects of spring and late summer applications of lambda-cyhalothrin on freshwater microcosms.

PubMed

Van Wijngaarden, R P A; Brock, T C M; van den Brink, P J; Gylstra, R; Maund, S J

2006-02-01

The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a 50-cm-deep experimental ditch system containing communities typical of macrophyte-dominated freshwater ecosystems. Effects on macroinvertebrates, zooplankton, phytoplankton, macrophytes, and community metabolism were assessed and evaluated using univariate and multivariate statistical techniques. The macroinvertebrate community responded most clearly to treatment and, as anticipated, insects and crustaceans were among the most sensitive organisms. Statistical analysis showed that the underlying community structure was significantly different between the spring and summer experiments. However, the most sensitive species (Chaoborus obscuripes and Gammarus pulex) were abundant in spring as well as in late summer. In spring and late summer, only slight and transient effects were observed at the community level in the 10-ng/L treatment. Overall, the study did not show substantial differences in the responses of sensitive taxa between spring and late summer treatments, and effects thresholds were similar irrespective of season of treatment.

Risk Factors Associated with Mortality and Increased Drug Costs in Nonvariceal Upper Gastrointestinal Bleeding.

PubMed

Lu, Mingliang; Sun, Gang; Zhang, Xiu-li; Zhang, Xiao-mei; Liu, Qing-sen; Huang, Qi-yang; Lau, James W Y; Yang, Yun-sheng

2015-06-01

To determine risk factors associated with mortality and increased drug costs in patients with nonvariceal upper gastrointestinal bleeding. We retrospectively analyzed data from patients hospitalized with nonvariceal upper gastrointestinal bleeding between January 2001-December 2011. Demographic and clinical characteristics and drug costs were documented. Univariate analysis determined possible risk factors for mortality. Statistically significant variables were analyzed using a logistic regression model. Multiple linear regression analyzed factors influencing drug costs. p < 0.05 was considered statistically significant. The study included data from 627 patients. Risk factors associated with increased mortality were age > 60, systolic blood pressure<100 mmHg, lack of endoscopic examination, comorbidities, blood transfusion, and rebleeding. Drug costs were higher in patients with rebleeding, blood transfusion, and prolonged hospital stay. In this patient cohort, re-bleeding rate is 11.20% and mortality is 5.74%. The mortality risk in patients with comorbidities was higher than in patients without comorbidities, and was higher in patients requiring blood transfusion than in patients not requiring transfusion. Rebleeding was associ-ated with mortality. Rebleeding, blood transfusion, and prolonged hospital stay were associated with increased drug costs, whereas bleeding from lesions in the esophagus and duodenum was associated with lower drug costs.

An Assessment of Organizational Health Literacy Practices at an Academic Health Center.

PubMed

Prince, Latrina Y; Schmidtke, Carsten; Beck, Jules K; Hadden, Kristie B

Organizational health literacy is the degree to which an organization considers and promotes the health literacy of patients. Addressing health literacy at an organizational level has the potential to have a greater impact on more health consumers in a health system than individual-level approaches. The purpose of this study was to assess health care practices at an academic health center using the 10 attributes of a health-literate health care organization. Using a survey research design, the Health Literate Healthcare Organization 10-Item Questionnaire was administered online using total population sampling. Employees (N = 10 300) rated the extent that their organization's health care practices consider and promote patients' health literacy. Differences in responses were assessed using factorial analysis of variance. The mean response was 4.7 on a 7-point Likert scale. Employee training and communication about costs received the lowest ratings. Univariate analyses revealed that there were no statistically significant differences (P = .05) by employees' health profession, years of service, or level of patient contact. There were statistically significant differences by highest education obtained with lowest ratings from employees with college degrees. Survey responses indicate a need for improvements in health care practices to better assist patients with inadequate health literacy.

Disadvantage of survival outcomes in widowed patients with colorectal neuroendocrine neoplasm: an analysis of surveillance, epidemiology and end results database.

PubMed

Li, Jing; Wang, Ying; Han, Fang; Wang, Zhu; Xu, Lichun; Tong, Jiandong

2016-12-13

Marital status correlates with health. Our goal was to examine the impact of marital status on the survival outcomes of patients with colorectal neuroendocrine neoplasms (NENs). The Surveillance, Epidemiology and End Results program was used to identify 1,289 eligible patients diagnosed between 2004 and 2010 with colorectal NENs. Statistical analyses were performed using Chi-square, Kaplan-Meier, and Cox regression proportional hazards methods. Patients in the widowed group had the highest proportion of larger tumor (>2cm), and higher ratio of poor grade (Grade III and IV) and more tumors at advanced stage (P<0.05). The 5-year cause specific survival (CSS) was 76% in the married group, 51% in the widowed group, 73% in the single group, and 72% in the divorced/separated group, which manifest statistically significant difference in the univariate log-rank test and Cox regression model (P<0.05). Furthermore, marital status was an independent prognostic factor only in Distant stage (P<0.001). In conclusion, patients in widowed group were at greater risk of cancer specific mortality from colorectal NENs and social support may lead to improved outcomes for patients with NENs.

Predictors of neonatal outcome in women with severe preeclampsia or eclampsia between 24 and 33 weeks' gestation.

PubMed

Witlin, A G; Saade, G R; Mattar, F; Sibai, B M

2000-03-01

We sought to characterize predictors of neonatal outcome in women with severe preeclampsia or eclampsia who were delivered of their infants preterm. We performed a retrospective analysis of 195 pregnancies delivered between 24 and 33 weeks' gestation because of severe preeclampsia or eclampsia. Multiple logistic regression and univariate chi(2) analysis were performed for the dependent outcome variables of survival and respiratory distress syndrome by use of independent fetal and maternal variables. A P value of <.05 was considered significant. In the multivariate analysis, respiratory distress syndrome was inversely related to gestational age at delivery (P =.0018) and directly related to cesarean delivery (P =.02), whereas survival was directly related to birth weight (P =.00025). There was no correlation in the multivariate analysis between respiratory distress syndrome or survival and corticosteroid use, composite neonatal morbidity, mean arterial pressure, eclampsia, or abruptio placentae. In the univariate analysis respiratory distress syndrome was associated with cesarean delivery (odds ratio, 7.19; 95% confidence interval, 2. 91-18.32). The incidence of intrauterine growth restriction increased as gestational age advanced. Furthermore, intrauterine growth restriction decreased survival in both the multivariate (P =. 038; odds ratio, 13.2; 95% confidence interval, 1.16-151.8) and univariate (P =.001; odds ratio, 5.88; 95% confidence interval, 1. 81-19.26) analyses. The presence of intrauterine growth restriction adversely affected survival independently of other variables. Presumed intrauterine stress, as reflected by the severity of maternal disease, did not improve neonatal outcome.

Influence of stromal refractive index and hydration on corneal laser refractive surgery.

PubMed

de Ortueta, Diego; von Rüden, Dennis; Magnago, Thomas; Arba Mosquera, Samuel

2014-06-01

To evaluate the influence of the stromal refractive index and hydration on postoperative outcomes in eyes that had corneal laser refractive surgery using the Amaris laser system. Augenzentrum Recklinghausen, Recklinghausen, Germany. Comparative case series. At the 6-month follow-up, right eyes were retrospectively analyzed. The effect of the stromal refractive index and hydration on refractive outcomes was assessed using univariate linear and multilinear correlations. Sixty eyes were analyzed. Univariate linear analyses showed that the stromal refractive index and hydration were correlated with the thickness of the preoperative exposed stroma and was statistically different for laser in situ keratomileusis and laser-assisted subepithelial keratectomy treatments. Univariate multilinear analyses showed that the spherical equivalent (SE) was correlated with the attempted SE and stromal refractive index (or hydration). Analyses suggest overcorrections for higher stromal refractive index values and for lower hydration values. The stromal refractive index and hydration affected postoperative outcomes in a subtle, yet significant manner. An adjustment toward greater attempted correction in highly hydrated corneas and less intended correction in low hydrated corneas might help optimize refractive outcomes. Mr. Magnago and Dr. Arba-Mosquera are employees of and Dr. Diego de Ortueta is a consultant to Schwind eye-tech-solutions GmbH & Co. KG. Mr. Rüden has no financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

An Extension of Dominance Analysis to Canonical Correlation Analysis

ERIC Educational Resources Information Center

Huo, Yan; Budescu, David V.

2009-01-01

Dominance analysis (Budescu, 1993) offers a general framework for determination of relative importance of predictors in univariate and multivariate multiple regression models. This approach relies on pairwise comparisons of the contribution of predictors in all relevant subset models. In this article we extend dominance analysis to canonical…

An R2 statistic for fixed effects in the linear mixed model.

PubMed

Edwards, Lloyd J; Muller, Keith E; Wolfinger, Russell D; Qaqish, Bahjat F; Schabenberger, Oliver

2008-12-20

Statisticians most often use the linear mixed model to analyze Gaussian longitudinal data. The value and familiarity of the R(2) statistic in the linear univariate model naturally creates great interest in extending it to the linear mixed model. We define and describe how to compute a model R(2) statistic for the linear mixed model by using only a single model. The proposed R(2) statistic measures multivariate association between the repeated outcomes and the fixed effects in the linear mixed model. The R(2) statistic arises as a 1-1 function of an appropriate F statistic for testing all fixed effects (except typically the intercept) in a full model. The statistic compares the full model with a null model with all fixed effects deleted (except typically the intercept) while retaining exactly the same covariance structure. Furthermore, the R(2) statistic leads immediately to a natural definition of a partial R(2) statistic. A mixed model in which ethnicity gives a very small p-value as a longitudinal predictor of blood pressure (BP) compellingly illustrates the value of the statistic. In sharp contrast to the extreme p-value, a very small R(2) , a measure of statistical and scientific importance, indicates that ethnicity has an almost negligible association with the repeated BP outcomes for the study.

Young Vs Old Colorectal Cancer in Indian Subcontinent: a Tertiary Care Center Experience.

PubMed

Pokharkar, Ashish B; Bhandare, Manish; Patil, Prachi; Mehta, Shaesta; Engineer, Reena; Saklani, Avanish P

2017-12-01

This study aims to compare patient, tumor, treatment-related factors and survival between young (<45 years) and old (>45 years) Indian colorectal cancer (CRC) patients. Total 778 patients of CRC were registered at tertiary cancer center in India between 1 August 2013 and 31 July 2014. Patients were followed up for median period of 27.73 months. Data regarding patient, tumor, treatment and survival-related factors were collected. Patients were divided in young (≤45 years) and old (>45 years) age groups. Statistical analysis was done with SPSS software version 23. Young age group patients presented more commonly with poor histology, node-positive disease, and rectal site. Younger age group patients received multiple lines of neoadjuvant treatment. There was no significant overall survival difference in both groups of patients. On stratified stage-wise analysis, no significant overall survival (OS) difference was found between two groups (young vs old-1- and 3-year OS: 85.2 and 61.5% vs 81.5 and 64.5%, respectively; P  = 0.881). On univariate analysis, gender, performance status, site, stage, differentiation, TRG, CRM status, signet ring type, and CEA level were significant prognostic factors. In disease-free survival (DFS) analysis, it is found that there is statistically significant difference in DFS (young vs old: 1 and 3 years; 77.6 and 62.8% vs 85.8 and 74.1%, respectively; P value, 0.02), but when OS was analyzed for same group of patient, there was no statistical difference ( P  = 0.302). This study confirms the high incidence rates of CRC in young Indian patients. There is no OS difference between two age groups. In operated group of patients, there is higher DFS in older patients but no OS advantage at 3 years follow-up. Further long-term follow-up is required to see any OS difference.

Evaluation of redundancy analysis to identify signatures of local adaptation.

PubMed

Capblancq, Thibaut; Luu, Keurcien; Blum, Michael G B; Bazin, Eric

2018-05-26

Ordination is a common tool in ecology that aims at representing complex biological information in a reduced space. In landscape genetics, ordination methods such as principal component analysis (PCA) have been used to detect adaptive variation based on genomic data. Taking advantage of environmental data in addition to genotype data, redundancy analysis (RDA) is another ordination approach that is useful to detect adaptive variation. This paper aims at proposing a test statistic based on RDA to search for loci under selection. We compare redundancy analysis to pcadapt, which is a nonconstrained ordination method, and to a latent factor mixed model (LFMM), which is a univariate genotype-environment association method. Individual-based simulations identify evolutionary scenarios where RDA genome scans have a greater statistical power than genome scans based on PCA. By constraining the analysis with environmental variables, RDA performs better than PCA in identifying adaptive variation when selection gradients are weakly correlated with population structure. Additionally, we show that if RDA and LFMM have a similar power to identify genetic markers associated with environmental variables, the RDA-based procedure has the advantage to identify the main selective gradients as a combination of environmental variables. To give a concrete illustration of RDA in population genomics, we apply this method to the detection of outliers and selective gradients on an SNP data set of Populus trichocarpa (Geraldes et al., 2013). The RDA-based approach identifies the main selective gradient contrasting southern and coastal populations to northern and continental populations in the northwestern American coast. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Exposure-response analysis of alectinib in crizotinib-resistant ALK-positive non-small cell lung cancer.

PubMed

Morcos, Peter N; Nueesch, Eveline; Jaminion, Felix; Guerini, Elena; Hsu, Joy C; Bordogna, Walter; Balas, Bogdana; Mercier, Francois

2018-05-10

Alectinib is a selective and potent anaplastic lymphoma kinase (ALK) inhibitor that is active in the central nervous system (CNS). Alectinib demonstrated robust efficacy in a pooled analysis of two single-arm, open-label phase II studies (NP28673, NCT01801111; NP28761, NCT01871805) in crizotinib-resistant ALK-positive non-small-cell lung cancer (NSCLC): median overall survival (OS) 29.1 months (95% confidence interval [CI]: 21.3-39.0) for alectinib 600 mg twice daily (BID). We investigated exposure-response relationships from final pooled phase II OS and safety data to assess alectinib dose selection. A semi-parametric Cox proportional hazards model analyzed relationships between individual median observed steady-state trough concentrations (C trough,ss ) for combined exposure of alectinib and its major metabolite (M4), baseline covariates (demographics and disease characteristics) and OS. Univariate logistic regression analysis analyzed relationships between C trough,ss and incidence of adverse events (AEs: serious and Grade ≥ 3). Overall, 92% of patients (n = 207/225) had C trough,ss data and were included in the analysis. No statistically significant relationship was found between C trough,ss and OS following alectinib treatment. The only baseline covariates that statistically influenced OS were baseline tumor size and prior crizotinib treatment duration. Larger baseline tumor size and shorter prior crizotinib treatment were both associated with shorter OS. Logistic regression confirmed no significant relationship between C trough,ss and AEs. Alectinib 600 mg BID provides systemic exposures at plateau of response for OS while maintaining a well-tolerated safety profile. This analysis confirms alectinib 600 mg BID as the recommended global dose for patients with crizotinib-resistant ALK-positive NSCLC.

An Investigation of Integrated Sizing for US Army Men and Women

DTIC Science & Technology

1981-08-01

number) Anthropometry U.S. Army Field Clothing Mee, surem, ent (s) Military Personnel Sizing (Clothing) Body Size Men Clothing Design Sizes...are larger. ’Ibid. ŕ°White, Robert M. and Edmund Churchill, 1.971, The Body Size of Soldiers, U.S. Army Anthropometry - 1966, Technical Report 72-51...1977, Anthropometry of Women in the U.S. Army--1977; Report No. 2 - The Basic Univariate Statistics, Technical Report NATICK/TR-77/024, U.S. Army

In vivo microvascular and macrovascular endothelial function is not associated with circulating dimethylarginines in patients with rheumatoid arthritis: a prospective analysis of the DRACCO cohort.

PubMed

Dimitroulas, Theodoros; Sandoo, Aamer; Hodson, James; Smith, Jacqueline P; Kitas, George D

2016-07-01

To examine associations between asymmetric (ADMA), symmetric dimethylarginine (SDMA) and ADMA:SDMA ratio with assessments of endothelial function and coronary artery perfusion in RA patients. ADMA and SDMA levels were measured in 197 RA individuals [144 (77.4%) females, median age: 66 years (quartiles: 59-73)]. Patients underwent assessments of microvascular endothelium-dependent and endothelium-independent function, macrovascular endothelium-dependent and endothelium-independent function and vascular morphology (pulse wave analysis, carotid intima-media thickness (cIMT), and carotid plaque). Coronary perfusion was assessed by subendocardial viability ratio (SEVR). SEVR correlated with SDMA (r = 0.172, p = 0.026) and ADMA:SDMA (r = -0.160, p = 0.041) in univariable analysis, but not in multivariable analysis accounting for confounding factors. Neither ADMA:SDMA ratio nor SDMA were significantly correlated with microvascular or macrovascular endothelial function, or with arterial stiffness and cIMT. Within subgroup of patients (n = 26) with high inflammatory markers, a post-hoc analysis showed that SDMA and the ADMA:SDMA ratio were significantly associated with endothelium-dependent microvascular function in univariable analysis, with Pearson's r correlation coefficients of -0.440 (p = 0.031) and 0.511 (p = 0.011), respectively. Similar finding were established between ADMA:SDMA ratio and arterial stiffness in univariable analysis, with Pearson's r of 0.493, (p = 0.024). Dimethylarginines were not found to be significantly associated with several assessments of vascular function and morphology in patients with RA, however, post-hoc analysis indicates that there may be associations in patients with raised inflammatory markers. Our results suggest that dysregulated NO metabolism may not be the sole mechanism for the development of preclinical atherosclerosis in RA.

High Ki-67 Immunohistochemical Reactivity Correlates With Poor Prognosis in Bladder Carcinoma

PubMed Central

Luo, Yihuan; Zhang, Xin; Mo, Meile; Tan, Zhong; Huang, Lanshan; Zhou, Hong; Wang, Chunqin; Wei, Fanglin; Qiu, Xiaohui; He, Rongquan; Chen, Gang

2016-01-01

Abstract Ki-67 is considered as one of prime biomarkers to reflect cell proliferation and immunohistochemical Ki-67 staining has been widely applied in clinical pathology. To solve the widespread controversy whether Ki-67 reactivity significantly predicts clinical prognosis of bladder carcinoma (BC), we performed a comprehensive meta-analysis by combining results from different literature. A comprehensive search was conducted in the Chinese databases of WanFang, China National Knowledge Infrastructure and Chinese VIP as well as English databases of PubMed, ISI web of science, EMBASE, Science Direct, and Wiley online library. Independent studies linking Ki-67 to cancer-specific survival (CSS), disease-free survival (DFS), overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) were included in our meta-analysis. With the cut-off values literature provided, hazard ratio (HR) values between the survival distributions were extracted and later combined with STATA 12.0. In total, 76 studies (n = 13,053 patients) were eligible for the meta-analysis. It was indicated in either univariate or multivariate analysis for survival that high Ki-67 reactivity significantly predicted poor prognosis. In the univariate analysis, the combined HR for CSS, DFS, OS, PFS, and RFS were 2.588 (95% confidence interval [CI]: 1.623–4.127, P < 0.001), 2.697 (95%CI: 1.874–3.883, P < 0.001), 2.649 (95%CI: 1.632–4.300, P < 0.001), 3.506 (95%CI: 2.231–5.508, P < 0.001), and 1.792 (95%CI: 1.409–2.279, P < 0.001), respectively. The pooled HR of multivariate analysis for CSS, DFS, OS, PFS, and RFS were 1.868 (95%CI: 1.343–2.597, P < 0.001), 2.626 (95%CI: 2.089–3.301, P < 0.001), 1.104 (95%CI: 1.008–1.209, P = 0.032), 1.518 (95%CI: 1.299–1.773, P < 0.001), and 1.294 (95%CI: 1.203–1.392, P < 0.001), respectively. Subgroup analysis of univariate analysis by origin showed that Ki-67 reactivity significantly correlated with all 5 clinical outcome in Asian and European-American patients (P < 0.05). For multivariate analysis, however, the pooled results were only significant for DFS, OS, and RFS in Asian patients, for CSS, DFS, PFS, and RFS in European-American patients (P < 0.05). In the subgroup with low cut-off value (<20%), our meta-analysis indicated that high Ki-67 reactivity was significantly correlated with worsened CSS, DFS, OS, PFS, and RFS on univariate analysis (P < 0.05). For multivariate analysis, the meta-analysis of literature with low cut-off value (<20%) demonstrated that high Ki-67 reactivity predicted shorter DFS, PFS, and RFS in BC patients (P < 0.05). In the subgroup analysis of high cut-off value (≥20%), our meta-analysis indicated that high Ki-67 reactivity, in either univariate or multivariate analysis, significantly correlated with all five clinical outcomes in BC patients (P < 0.05). The meta-analysis indicates that high Ki-67 reactivity significantly correlates with deteriorated clinical outcomes in BC patients and that Ki-67 can be considered as an independent indicator for the prognosis by the meta-analyses of multivariate analysis. PMID:27082587

Differences in stone size and ureteral dilation between obstructing proximal and distal ureteral calculi.

PubMed

Eisner, Brian H; Pedro, Renato; Namasivayam, Saravanan; Kambadakone, Avinash; Sahani, Dushyant V; Dretler, Stephen P; Monga, Manoj

2008-09-01

To examine the differences in ureteral dilation and calculus size between obstructing proximal and distal ureteral stones. A retrospective review of computed tomography (CT) scans from 176 consecutive patients with obstructing ureteral calculi was performed. For the calculi, the axial diameter was defined as the largest stone diameter on the axial CT images, and the coronal length was defined as the cephalocaudal length of the stone measured on the coronal CT images. Univariate and multivariate statistical analyses were performed. A total of 65 proximal and 111 distal ureteral calculi were analyzed. On univariate analysis, the proximal calculi were associated with a greater degree of ureteral dilation (mean 6.1 mm vs 5.3 mm, P = .01) and had a greater coronal length (mean 9.9 mm vs 8.3 mm, P = .005) than distal calculi. This association was also true on the multivariate analysis, which controlled for age and sex (P = .0004). No statistically significant difference was found in the axial calculus diameter for the proximal and distal stones (mean 5.3 mm vs 5.0 mm, P = .29). In a subset of 50 patients whose contralateral ureters (without stones) were measured for control comparison, the ureteral dilation in the ureters with stones was significantly greater than in the control ureters (proximal ureter 6.2 mm vs 4.3 mm, P = .001; distal ureter 4.7 mm vs 3.8 mm, P = .004). For proximal calculi, 72.3% were associated with ureteral dilation of less than 7 mm, 23.1% with 7-10 mm, and 4.6% with greater than 10 mm. For the distal calculi, 90.1% were associated with ureteral dilation of less than 7 mm, 6.3% with 7-10 mm, and 3.6% with greater than 10 mm. The coronal length was the largest measured diameter in 94% of the calculi, and the mean calculus coronal length was significantly greater than the mean axial diameter (8.9 mm vs 5.1 mm, respectively, P < .001). The results of our study have shown that proximal ureteral calculi are associated with a significantly greater degree of ureteral dilation and larger coronal length than are distal calculi. These findings should guide the endoscopist in planning intracorporeal ureteroscopic lithotripsy. We suggest obtaining CT coronal images to more accurately characterize obstructing ureteral stones.

Association of serum N(ε)-Carboxy methyl lysine with severity of diabetic retinopathy.

PubMed

Mishra, Nibha; Saxena, Sandeep; Shukla, Rajendra K; Singh, Vinita; Meyer, Carsten H; Kruzliak, Peter; Khanna, Vinay K

2016-04-01

To correlate serum levels of N-epsilon-carboxy methyl lysine (N(ε)-CML) with severity of retinopathy, in vivo macular edema and disruption of external limiting membrane (ELM) and photoreceptor ellipsoid zone in type 2 diabetes mellitus (DM). Consecutive cases of type 2 DM [diabetes mellitus with no retinopathy (No DR) (n=20); non- proliferative diabetic retinopathy (NPDR) with diabetic macular edema (n=20); proliferative diabetic retinopathy with diabetic macular edema (PDR) (n=20)] and healthy controls (n=20) between the ages of 40 and 65 years were included (power of study=93.8%). In vivo histology of retinal layers was assessed using spectral domain optical coherence tomography. Every study subject underwent macular thickness analysis using the macular cube 512×128 feature. Disruption of ELM and photoreceptor ellipsoid zone was graded: grade 0, no disruption of ELM and ellipsoid zone; grade 1, ELM disrupted and ellipsoid zone intact; grade 2, both ELM and ellipsoid zone disrupted. Data were statistically analyzed. The mean levels of N(ε)-CML were 31.34±21.23 ng/ml, 73.88±35.01 ng/ml, 91.21±66.65 ng/ml, and 132.08±84.07 ng/ml in control, No DR, NPDR and PDR respectively. N(ε)-CML level was significantly different between the study groups (control, No DR, NPDR and PDR) (p<0.001). Mean logMAR visual acuity decreased with increased levels of N(ε)-CML (p<0.001). The association of N(Ɛ)CML with the grades of disruption was found to be statistically significant (F value=18.48, p<0.001). Univariate analysis was done with N(Ɛ)-CML as a dependent variable. The values of N(Ɛ)-CML were normalized (log10) and were subjected to univariate analysis with fasting blood glucose level, glycosylated hemoglobin, central subfield macular thickness and cube average thickness among the diseased groups (NPDR and PDR) that act as confounders. It was found that none of the variables had significant effect on N(Ɛ)-CML (fasting blood glucose p=0.12, HBA1c p=0.65, central subfield macular thickness p=0.13, cube average thickness p=0.19). N(Ɛ)-CML tends to be a significant and important predictor of grade of ELM and ellipsoid zone disruption in diabetic retinopathy. Increased N(ε)-CML levels are associated with increased severity of diabetic retinopathy, macular edema and structural changes in macula that is ELM and ellipsoid zone disruption, which serves as a prognosticator of visual outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

Association of arsenobetaine with beta-cell function assessed by homeostasis model assessment (HOMA) in nondiabetic Koreans: data from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009.

PubMed

Baek, Kiook; Lee, Namhoon; Chung, Insung

2017-01-01

Arsenic is known as an endocrine disruptor that people are exposed to through various sources such as drinking water and indigestion of marine products. Although some epidemiological and animal studies have reported a correlation between arsenic exposure and diabetes development, there are limited studies regarding the toxic effects of organic arsenic including arsenobetaine on the human body. Here, we analyzed the association between urine arsenobetaine and the homeostasis model assessment of β-cell function (HOMA-β), which is an index for predicting diabetes development and reflecting the function of pancreatic β-cells. In the fourth Korea National Health and Nutrition Examination Survey (KNHANES), health and nutrition surveys and screening tests were performed. Of the total survey population, people with confirmed values for urine total arsenic and arsenobetaine were included, and known diabetic patients were excluded. A total 369 participants were finally included in the study. We collected surveys on health, height, body weight, body mass index, blood mercury level, fasting glucose level, and serum insulin level and calculated HOMA index. Owing to sexual discrepancy, we performed sexually stratified analysis. Urine total arsenic and total arsenic minus arsenobetaine was not associated with HOMA-IR and HOMA-β in univariate analysis or in sexually stratified analysis. However, urine arsenobetaine showed a statistically significant relationship with HOMA-β in univariate analysis, and only male participants showed a significant correlation in sexually stratified analysis. In the analysis adjusted for age, BMI, smoking, alcohol drinking, physical activity and blood mercury, the HOMA-β value in the group below the 25th percentile of arsenobetaine was significantly higher than the group between 50 and 75th percentile, while no difference was shown for HOMA-IR. In sexually stratified analysis, The value of HOMA-β was significantly higher in male participants with below the 25th percentile urine arsenobetaine than the group between 25 and 50th and between 50 and 75th, while no difference was shown for HOMA-IR. However, female participants did not demonstrate a relationship between HOMA-IR, HOMA-β and urine arsenobetaine. This study revealed the association between urine arsenobetaine and pancreatic β-cell function assessed by HOMA-β in the normal population (without diabetes), especially in males, despite adjusting for factors affecting pancreatic β-cell function and diabetes.

Clinical dysphagia risk predictors after prolonged orotracheal intubation

PubMed Central

de Medeiros, Gisele Chagas; Sassi, Fernanda Chiarion; Mangilli, Laura Davison; Zilberstein, Bruno; de Andrade, Claudia Regina Furquim

2014-01-01

OBJECTIVES: To elucidate independent risk factors for dysphagia after prolonged orotracheal intubation. METHODS: The participants were 148 consecutive patients who underwent clinical bedside swallowing assessments from September 2009 to September 2011. All patients had received prolonged orotracheal intubations and were admitted to one of several intensive care units of a large Brazilian school hospital. The correlations between the conducted water swallow test results and dysphagia risk levels were analyzed for statistical significance. RESULTS: Of the 148 patients included in the study, 91 were male and 57 were female (mean age, 53.64 years). The univariate analysis results indicated that specific variables, including extraoral loss, multiple swallows, cervical auscultation, vocal quality, cough, choking, and other signs, were possible significant high-risk indicators of dysphagia onset. The multivariate analysis results indicated that cervical auscultation and coughing were independent predictive variables for high dysphagia risk. CONCLUSIONS: Patients displaying extraoral loss, multiple swallows, cervical auscultation, vocal quality, cough, choking and other signs should benefit from early swallowing evaluations. Additionally, early post-extubation dysfunction recognition is paramount in reducing the morbidity rate in this high-risk population. PMID:24473554

Mesothelioma in the Quebec chrysotile mining region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Case, B.W.; Armstrong, B.; McDonald, J.C.

Previous studies of incidence of mesothelioma and lung tissue burden in workers and nonworkers in the Quebec chrysotile mining region showed that mesothelioma incidence is very slightly increased in the mining area, and that tremolite, or even commercial amphiboles, are responsible (and chrysotile is not). Recently, one of us (BC) noted an increase in the numbers of cases of mesothelioma coming to autopsy in the mining region. There were 19 cases, all confirmed histologically, since 1982, vs. 6 that we know of in the previous 10 y. Eighteen were occupationally exposed; one was the wife of chrysotile miner/miller. We examinedmore » lung tissue from 9 cases matched to controls of the same sex and age, dying in the same years in the same hospitals, without evidence of malignant disease. We found an excess in cases of typical asbestos bodies; tremolite fibers; and total amphiboles. In univariate linear relative risk analysis, both longer (>8 {mu}m) and shorter fibers are significant. Multivariate analysis indicates that while adjustment of chrysotile lung content for tremolite content eliminates any statistical effect of chrysotile, the reverse comparison retains significance.« less

Decreased expression of class III β-tubulin is associated with unfavourable prognosis in patients with malignant melanoma.

PubMed

Shimizu, Akira; Kaira, Kyoichi; Yasuda, Masahito; Asao, Takayuki; Ishikawa, Osamu

2016-02-01

Class III β-tubulin (TUBB3) has been recognized as being associated with resistance to taxane-based regimens in several cancers. However, little is known about the clinicopathological significance of TUBB3 expression in patients with cutaneous malignant melanoma. The aim of this study was to examine the prognostic significance of TUBB3 expression in cutaneous malignant melanoma. A total of 106 patients with surgically resected cutaneous malignant melanoma were assessed. Tumour sections were immunohistochemically stained for TUBB3, Ki-67 and microvessel density with CD34. TUBB3 was highly expressed in 80% (85/106) of patients. No statistically significant relationship was observed between the high expression of TUBB3 and any variables. On univariate analysis, ulceration, disease stage, TUBB3 and CD34 revealed a significant relationship with overall survival and progression-free survival. Multivariate analysis confirmed that a low TUBB3 expression was an independent prognostic factor for poor prognosis of cutaneous malignant melanoma. The decreased expression of TUBB3 could be a significant marker for predicting unfavourable prognosis in patients with cutaneous malignant melanoma.

What is the perception of biological risk by undergraduate nursing students?

PubMed Central

Moreno-Arroyo, Mª Carmen; Puig-Llobet, Montserrat; Falco-Pegueroles, Anna; Lluch-Canut, Maria Teresa; García, Irma Casas; Roldán-Merino, Juan

2016-01-01

Abstract Objective: to analyze undergraduate nursing students' perception of biological risk and its relationship with their prior practical training. Method: a descriptive cross-sectional study was conducted among undergraduate nursing students enrolled in clinical practice courses in the academic year 2013-2014 at the School of Nursing at the University of Barcelona. Variables: sociodemographic variables, employment, training, clinical experience and other variables related to the assessment of perceived biological risk were collected. Both a newly developed tool and the Dimensional Assessment of Risk Perception at the worker level scale (Escala de Evaluación Dimensional del Riesgo Percibido por el Trabajador, EDRP-T) were used. Statistical analysis: descriptive and univariate analysis were used to identify differences between the perception of biological risk of the EDRP-T scale items and sociodemographic variables. Results: students without prior practical training had weaker perceptions of biological risk compared to students with prior practical training (p=0.05 and p=0.04, respectively). Weaker perceptions of biological risk were found among students with prior work experience. Conclusion: practical training and work experience influence the perception of biological risk among nursing students. PMID:27384468

The crowding effect and morphometric variability in Echinostoma caproni (Digenea: Echinostomatidae) from ICR mice.

PubMed

Stillson, Lindsey L; Platt, Thomas R

2007-04-01

Population density, or crowding, was examined to determine its effect on the morphometric variability of Echinostoma caproni (Digenea) in ICR mice. Six mice were infected with 25 and 100 metacercariae, and a single mouse was infected with 300 metacercariae. All mice were infected at necropsy 22 days postinfection with recoveries of 77%, 69%, and 7.3%, respectively. Whole mounts were prepared, and 31 characters were evaluated (25 direct measurements and 6 ratios). Univariate and multivariate statistical analysis revealed significant differences between adult worms from all 3 groups. Twenty-seven of 31 characters showed significant within-group differences, with the primary differences between worms from 25/100 versus 300 metacercariae infections. Discriminant function analysis yielded a 100% correct classification based on infection size, which is consistent with studies on distinct species of Echinostoma. The low recovery from the mouse infected with 300 metacercariae suggests inflammatory expulsion of juvenile worms and the possibility of immunity as a factor in the crowding effect. These results suggest that external factors may affect morphometric variability of digenetic trematodes to a larger degree than previously recognized.

Can outcome of pancreatic pseudocysts be predicted? Proposal for a new scoring system.

PubMed

Şenol, Kazım; Akgül, Özgür; Gündoğdu, Salih Burak; Aydoğan, İhsan; Tez, Mesut; Coşkun, Faruk; Tihan, Deniz Necdet

2016-03-01

The spontaneous resolution rate of pancreatic pseudocysts (PPs) is 86%, and the serious complication rate is 3-9%. The aim of the present study was to develop a scoring system that would predict spontaneous resolution of PPs. Medical records of 70 patients were retrospectively reviewed. Two patients were excluded. Demographic data and laboratory measurements were obtained from patient records. Mean age of the 68 patients included was 56.6 years. Female:male ratio was 1.34:1. Causes of pancreatitis were stones (48.5%), alcohol consumption (26.5%), and unknown etiology (25%). Mean size of PP was 71 mm. Pseudocysts disappeared in 32 patients (47.1%). With univariate analysis, serum direct bilirubin level (>0.95 mg/dL), cyst carcinoembryonic antigen (CEA) level (>1.5), and cyst diameter (>55 mm) were found to be significantly different between patients with and without spontaneous resolution. In multivariate analysis, these variables were statistically significant. Scores were calculated with points assigned to each variable. Final scores predicted spontaneous resolution in approximately 80% of patients. The scoring system developed to predict resolution of PPs is simple and useful, but requires validation.

Clinical dysphagia risk predictors after prolonged orotracheal intubation.

PubMed

Medeiros, Gisele Chagas de; Sassi, Fernanda Chiarion; Mangilli, Laura Davison; Zilberstein, Bruno; Andrade, Claudia Regina Furquim de

2014-01-01

To elucidate independent risk factors for dysphagia after prolonged orotracheal intubation. The participants were 148 consecutive patients who underwent clinical bedside swallowing assessments from September 2009 to September 2011. All patients had received prolonged orotracheal intubations and were admitted to one of several intensive care units of a large Brazilian school hospital. The correlations between the conducted water swallow test results and dysphagia risk levels were analyzed for statistical significance. Of the 148 patients included in the study, 91 were male and 57 were female (mean age, 53.64 years). The univariate analysis results indicated that specific variables, including extraoral loss, multiple swallows, cervical auscultation, vocal quality, cough, choking, and other signs, were possible significant high-risk indicators of dysphagia onset. The multivariate analysis results indicated that cervical auscultation and coughing were independent predictive variables for high dysphagia risk. Patients displaying extraoral loss, multiple swallows, cervical auscultation, vocal quality, cough, choking and other signs should benefit from early swallowing evaluations. Additionally, early post-extubation dysfunction recognition is paramount in reducing the morbidity rate in this high-risk population.

The t-CWT: a new ERP detection and quantification method based on the continuous wavelet transform and Student's t-statistics.

PubMed

Bostanov, Vladimir; Kotchoubey, Boris

2006-12-01

This study was aimed at developing a method for extraction and assessment of event-related brain potentials (ERP) from single-trials. This method should be applicable in the assessment of single persons' ERPs and should be able to handle both single ERP components and whole waveforms. We adopted a recently developed ERP feature extraction method, the t-CWT, for the purposes of hypothesis testing in the statistical assessment of ERPs. The t-CWT is based on the continuous wavelet transform (CWT) and Student's t-statistics. The method was tested in two ERP paradigms, oddball and semantic priming, by assessing individual-participant data on a single-trial basis, and testing the significance of selected ERP components, P300 and N400, as well as of whole ERP waveforms. The t-CWT was also compared to other univariate and multivariate ERP assessment methods: peak picking, area computation, discrete wavelet transform (DWT) and principal component analysis (PCA). The t-CWT produced better results than all of the other assessment methods it was compared with. The t-CWT can be used as a reliable and powerful method for ERP-component detection and testing of statistical hypotheses concerning both single ERP components and whole waveforms extracted from either single persons' or group data. The t-CWT is the first such method based explicitly on the criteria of maximal statistical difference between two average ERPs in the time-frequency domain and is particularly suitable for ERP assessment of individual data (e.g. in clinical settings), but also for the investigation of small and/or novel ERP effects from group data.

The relationship between central corneal thickness and optic disc size in patients with primary open-angle glaucoma in a hospital-based population.

PubMed

Terai, Naim; Spoerl, Eberhard; Pillunat, Lutz E; Kuhlisch, Eberhard; Schmidt, Eckart; Boehm, Andreas G

2011-09-01

To investigate the relationship between central corneal thickness (CCT) and optic disc size in patients with primary open-angle glaucoma (POAG) in a hospital-based population. Data for the right eyes of 1435 White patients with POAG were included in a retrospective hospital-based study. All eyes underwent optic nerve head imaging using Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) and CCT measurement by ultrasound corneal pachymetry. Eyes with prior intraocular or corneal surgery were excluded. Low-quality HRT II images were also excluded. The impact of age, gender, CCT, intraocular pressure, cylindrical and spherical refractive error as independent factors on optic disc size was investigated in a multiple linear regression analysis. The data for 1104 right eyes qualified for participation in the study. The median age of these patients was 65 years. The median CCT was 547 μm (25th-75th percentile 522-575 μm). The median optic disc size was 2.21 mm(2) (25th-75th percentile 1.89-2.60 mm(2)). Multiple linear regression analysis revealed that age (p = 0.001), CCT (p = 0.001) and spherical equivalent (p = 0.049) were correlated to disc size according to the following formula: disc area = -0.004 × age - 0.001 × CCT - 0.014 × spherical equivalent +3.290. R(2) of the whole model was 0.021. Univariate regression analysis between age and disc area provided R(2) = 0.008 with p = 0.002. Univariate regression analysis between disc area and CCT provided R(2) = 0.005 with p = 0.02. In this retrospective hospital-based study we could not detect a clinically relevant correlation between optic disc size and CCT. The correlation between CCT and disc size and between age and disc size were statistically significant, but the R(2) values were very low. The results of the study are biased because of its hospital-based design, so the results of the study need to be confirmed in a large population-based study. © 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.

[Determinants of long-term survival in 38 patients with carcinoma of ampulla of Vater treated by local resection].

PubMed

Liu, Ning; Liang, Han; Li, Qiang; Wang, Dian-chang; Zhang, Ru-peng; Wang, Jia-cang; Hao, Xi-shan

2005-10-01

To investigate determinants of long-term survival for carcinoma of ampulla of Vater treated by local resection. The clinical and pathological data of 38 such patients treated by local resection from 1983 to 2003 were retrospectively analyzed. According to UICC staging system, there were T1 30, T2 7 and T3 1. Lymph nodes were involved in 4 during operation which was present in primary lesions larger than 2 cm across. All patients were treated by local resection. At first, external palpation was carried out to ascertain accessibility. Then with the duodenum opened, direct exploration was carried out. On deciding for resection, the common bile duct was probe explored which guided the circumferential ring resection 1 cm, away from the tumor, including all layers of duodenum, ampula and partial bile and terminal pancreatic ducts and the posterial wall of duodenum was completed in steps. Meticulous care was taken not to suture the pancreatic duct and endotheliation was ensured at the mouth of common bile duct and duodenum. The basal tissue was frozen sectioned to ensure negative stumps. The gall bladder of 6 patients was also resected. SPSS 10.0 software was used in data processing, log-rank test used in univariate analysis and Cox equation for multivariate analysis and Kaplan-Meirer method for the survival rates. Thirty-eight patients received local resection giving an operative mortality of 0% and morbidity of 13.2%. The 1-, 5- and 10-year survival rate was 83.5%, 51.4%, and 38.9%, respectively, with a median survival of 3.35 years. Up to now, 13 patients have survived for more than five years and 2 patients beyond ten years. The tumour size, tumour grading, lymph node status and UICC stage were significant prognostic factors in univariate analysis. However, only lymph node status was a statistically independent predictor of prognosis in multivariate analysis. Local excision is safe giving low morbidity and good survival in carefully selected cases. Preferably it is indicated only in high risk patients with a pT1 and well differentiated ampullary cancer smaller than 1 cm in diameter.

Remote Monitoring of Hypertension Diseases in Pregnancy: A Pilot Study

PubMed Central

Vandenberk, Thijs; Smeets, Christophe JP; De Cannière, Hélène; Molenberghs, Geert; Van Moerbeke, Anne; van den Hoogen, Anne; Robijns, Tiziana; Vonck, Sharona; Staelens, Anneleen; Storms, Valerie; Thijs, Inge M; Grieten, Lars; Gyselaers, Wilfried

2017-01-01

Background Although remote monitoring (RM) has proven its added value in various health care domains, little is known about the remote follow-up of pregnant women diagnosed with a gestational hypertensive disorders (GHD). Objective The aim of this study was to evaluate the added value of a remote follow-up program for pregnant women diagnosed with GHD. Methods A 1-year retrospective study was performed in the outpatient clinic of a 2nd level prenatal center where pregnant women with GHD received RM or conventional care (CC). Primary study endpoints include number of prenatal visits and admissions to the prenatal observation ward. Secondary outcomes include gestational outcome, mode of delivery, neonatal outcome, and admission to neonatal intensive care (NIC). Differences in continuous and categorical variables in maternal demographics and characteristics were tested using Unpaired Student’s two sampled t test or Mann-Whitney U test and the chi-square test. Both a univariate and multivariate analysis were performed for analyzing prenatal follow-up and gestational outcomes. All statistical analyses were done at nominal level, Cronbach alpha=.05. Results Of the 166 patients diagnosed with GHD, 53 received RM and 113 CC. After excluding 5 patients in the RM group and 15 in the CC group because of the missing data, 48 patients in RM group and 98 in CC group were taken into final analysis. The RM group had more women diagnosed with gestational hypertension, but less with preeclampsia when compared with CC (81.25% vs 42.86% and 14.58% vs 43.87%). Compared with CC, univariate analysis in RM showed less induction, more spontaneous labors, and less maternal and neonatal hospitalizations (48.98% vs 25.00%; 31.63% vs 60.42%; 74.49% vs 56.25%; and 27.55% vs 10.42%). This was also true in multivariate analysis, except for hospitalizations. Conclusions An RM follow-up of women with GHD is a promising tool in the prenatal care. It opens the perspectives to reverse the current evolution of antenatal interventions leading to more interventions and as such to ever increasing medicalized antenatal care. PMID:28279948

Dosimetric Predictors of Radiation-induced Acute Nausea and Vomiting in IMRT for Nasopharyngeal Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Victor H.F., E-mail: vhflee@hku.hk; Ng, Sherry C.Y.; Leung, T.W.

Purpose: We wanted to investigate dosimetric parameters that would predict radiation-induced acute nausea and vomiting in intensity-modulated radiation therapy (IMRT) for undifferentiated carcinoma of the nasopharynx (NPC). Methods and Materials: Forty-nine consecutive patients with newly diagnosed NPC were treated with IMRT alone in this prospective study. Patients receiving any form of chemotherapy were excluded. The dorsal vagal complex (DVC) as well as the left and right vestibules (VB-L and VB-R, respectively) were contoured on planning computed tomography images. A structure combining both the VB-L and the VB-R, named VB-T, was also generated. All structures were labeled organs at risk (OAR).more » A 3-mm three-dimensional margin was added to these structures and labeled DVC+3 mm, VB-L+3 mm, VB-R+3 mm, and VB-T+3 mm to account for physiological body motion and setup error. No weightings were given to these structures during optimization in treatment planning. Dosimetric parameters were recorded from dose-volume histograms. Statistical analysis of parameters' association with nausea and vomiting was performed using univariate and multivariate logistic regression. Results: Six patients (12.2%) reported Grade 1 nausea, and 8 patients (16.3%) reported Grade 2 nausea. Also, 4 patients (8.2%) complained of Grade 1 vomiting, and 4 patients (8.2%) experienced Grade 2 vomiting. No patients developed protracted nausea and vomiting after completion of IMRT. For radiation-induced acute nausea, V40 (percentage volume receiving at least 40Gy) to the VB-T and V40>=80% to the VB-T were predictors, using univariate analysis. On multivariate analysis, V40>=80% to the VB-T was the only predictor. There were no predictors of radiation-induced acute vomiting, as the number of events was too small for analysis. Conclusions: This is the first study demonstrating that a V40 to the VB-T is predictive of radiation-induced acute nausea. The vestibules should be labeled as sensitive OARs, and weightings should be considered for dose sparing during optimization in the treatment planning of IMRT.« less

Distortion Representation of Forecast Errors for Model Skill Assessment and Objective Analysis

NASA Technical Reports Server (NTRS)

Hoffman, Ross N.; Nehrkorn, Thomas; Grassotti, Christopher

1998-01-01

We proposed a novel characterization of errors for numerical weather predictions. A general distortion representation allows for the displacement and amplification or bias correction of forecast anomalies. Characterizing and decomposing forecast error in this way has several important applications, including the model assessment application and the objective analysis application. In this project, we have focused on the assessment application, restricted to a realistic but univariate 2-dimensional situation. Specifically, we study the forecast errors of the sea level pressure (SLP), the 500 hPa geopotential height, and the 315 K potential vorticity fields for forecasts of the short and medium range. The forecasts are generated by the Goddard Earth Observing System (GEOS) data assimilation system with and without ERS-1 scatterometer data. A great deal of novel work has been accomplished under the current contract. In broad terms, we have developed and tested an efficient algorithm for determining distortions. The algorithm and constraints are now ready for application to larger data sets to be used to determine the statistics of the distortion as outlined above, and to be applied in data analysis by using GEOS water vapor imagery to correct short-term forecast errors.

Predictors of Dropout by Female Obese Patients Treated with a Group Cognitive Behavioral Therapy to Promote Weight Loss.

PubMed

Sawamoto, Ryoko; Nozaki, Takehiro; Furukawa, Tomokazu; Tanahashi, Tokusei; Morita, Chihiro; Hata, Tomokazu; Komaki, Gen; Sudo, Nobuyuki

2016-01-01

To investigate predictors of dropout from a group cognitive behavioral therapy (CBT) intervention for overweight or obese women. 119 overweight and obese Japanese women aged 25-65 years who attended an outpatient weight loss intervention were followed throughout the 7-month weight loss phase. Somatic characteristics, socioeconomic status, obesity-related diseases, diet and exercise habits, and psychological variables (depression, anxiety, self-esteem, alexithymia, parenting style, perfectionism, and eating attitude) were assessed at baseline. Significant variables, extracted by univariate statistical analysis, were then used as independent variables in a stepwise multiple logistic regression analysis with dropout as the dependent variable. 90 participants completed the weight loss phase, giving a dropout rate of 24.4%. The multiple logistic regression analysis demonstrated that compared to completers the dropouts had significantly stronger body shape concern, tended to not have jobs, perceived their mothers to be less caring, and were more disorganized in temperament. Of all these factors, the best predictor of dropout was shape concern. Shape concern, job condition, parenting care, and organization predicted dropout from the group CBT weight loss intervention for overweight or obese Japanese women. © 2016 S. Karger GmbH, Freiburg.

Predictors of Dropout by Female Obese Patients Treated with a Group Cognitive Behavioral Therapy to Promote Weight Loss

PubMed Central

Sawamoto, Ryoko; Nozaki, Takehiro; Furukawa, Tomokazu; Tanahashi, Tokusei; Morita, Chihiro; Hata, Tomokazu; Komaki, Gen; Sudo, Nobuyuki

2016-01-01

Objective To investigate predictors of dropout from a group cognitive behavioral therapy (CBT) intervention for overweight or obese women. Methods 119 overweight and obese Japanese women aged 25-65 years who attended an outpatient weight loss intervention were followed throughout the 7-month weight loss phase. Somatic characteristics, socioeconomic status, obesity-related diseases, diet and exercise habits, and psychological variables (depression, anxiety, self-esteem, alexithymia, parenting style, perfectionism, and eating attitude) were assessed at baseline. Significant variables, extracted by univariate statistical analysis, were then used as independent variables in a stepwise multiple logistic regression analysis with dropout as the dependent variable. Results 90 participants completed the weight loss phase, giving a dropout rate of 24.4%. The multiple logistic regression analysis demonstrated that compared to completers the dropouts had significantly stronger body shape concern, tended to not have jobs, perceived their mothers to be less caring, and were more disorganized in temperament. Of all these factors, the best predictor of dropout was shape concern. Conclusion Shape concern, job condition, parenting care, and organization predicted dropout from the group CBT weight loss intervention for overweight or obese Japanese women. PMID:26745715

Low Alcohol and Cigarette Use Is Associated to the Risk of Developing Chronic Pancreatitis.

PubMed

Di Leo, Milena; Leandro, Gioacchino; Singh, Satish K; Mariani, Alberto; Bianco, Margherita; Zuppardo, Raffaella Alessia; Goni, Elisabetta; Rogger, Teresa Marzia; Di Mario, Francesco; Guslandi, Mario; De Cobelli, Francesco; Del Maschio, Alessandro; Testoni, Pier Alberto; Cavestro, Giulia Martina

2017-02-01

The aim of this study was to investigate the contribution of smoking and alcohol intake and pancreas divisum on the risk of developing chronic pancreatitis (CP). Consecutive patients with CP who underwent secretin-enhanced magnetic resonance cholangiopancreatography were compared with consecutive patients without pancreatic disease who underwent secretin-enhanced magnetic resonance cholangiopancreatography for irritable bowel syndrome. We enrolled 145 consecutive CP patients and 103 irritable bowel syndrome patients from 2010 to 2014. In a univariate analysis, statistically significant differences in sex, mean age, and the duration and amount of cigarette and alcohol use were found. Per a receiver operating characteristic curve analysis, thresholds for cigarette and alcohol consumption were, respectively, 5.5 cigarettes and 13.5 g daily. In a multivariate analysis, independent risk factors for CP were male sex (odds ratio [OR], 2.05), smoking more than 5.5 cigarettes per day (OR, 2.72), and drinking more than 13.5 g/d (OR, 6.35). In an Italian population, we confirmed smoking and alcohol as cofactors in the development of CP. This study shows that alcohol intake and smoking habits are 2 of the most important risk factors for the development of CP.

Missing Value Imputation Approach for Mass Spectrometry-based Metabolomics Data.

PubMed

Wei, Runmin; Wang, Jingye; Su, Mingming; Jia, Erik; Chen, Shaoqiu; Chen, Tianlu; Ni, Yan

2018-01-12

Missing values exist widely in mass-spectrometry (MS) based metabolomics data. Various methods have been applied for handling missing values, but the selection can significantly affect following data analyses. Typically, there are three types of missing values, missing not at random (MNAR), missing at random (MAR), and missing completely at random (MCAR). Our study comprehensively compared eight imputation methods (zero, half minimum (HM), mean, median, random forest (RF), singular value decomposition (SVD), k-nearest neighbors (kNN), and quantile regression imputation of left-censored data (QRILC)) for different types of missing values using four metabolomics datasets. Normalized root mean squared error (NRMSE) and NRMSE-based sum of ranks (SOR) were applied to evaluate imputation accuracy. Principal component analysis (PCA)/partial least squares (PLS)-Procrustes analysis were used to evaluate the overall sample distribution. Student's t-test followed by correlation analysis was conducted to evaluate the effects on univariate statistics. Our findings demonstrated that RF performed the best for MCAR/MAR and QRILC was the favored one for left-censored MNAR. Finally, we proposed a comprehensive strategy and developed a public-accessible web-tool for the application of missing value imputation in metabolomics ( https://metabolomics.cc.hawaii.edu/software/MetImp/ ).

Support vector machine for breast cancer classification using diffusion-weighted MRI histogram features: Preliminary study.

PubMed

Vidić, Igor; Egnell, Liv; Jerome, Neil P; Teruel, Jose R; Sjøbakk, Torill E; Østlie, Agnes; Fjøsne, Hans E; Bathen, Tone F; Goa, Pål Erik

2018-05-01

Diffusion-weighted MRI (DWI) is currently one of the fastest developing MRI-based techniques in oncology. Histogram properties from model fitting of DWI are useful features for differentiation of lesions, and classification can potentially be improved by machine learning. To evaluate classification of malignant and benign tumors and breast cancer subtypes using support vector machine (SVM). Prospective. Fifty-one patients with benign (n = 23) and malignant (n = 28) breast tumors (26 ER+, whereof six were HER2+). Patients were imaged with DW-MRI (3T) using twice refocused spin-echo echo-planar imaging with echo time / repetition time (TR/TE) = 9000/86 msec, 90 × 90 matrix size, 2 × 2 mm in-plane resolution, 2.5 mm slice thickness, and 13 b-values. Apparent diffusion coefficient (ADC), relative enhanced diffusivity (RED), and the intravoxel incoherent motion (IVIM) parameters diffusivity (D), pseudo-diffusivity (D*), and perfusion fraction (f) were calculated. The histogram properties (median, mean, standard deviation, skewness, kurtosis) were used as features in SVM (10-fold cross-validation) for differentiation of lesions and subtyping. Accuracies of the SVM classifications were calculated to find the combination of features with highest prediction accuracy. Mann-Whitney tests were performed for univariate comparisons. For benign versus malignant tumors, univariate analysis found 11 histogram properties to be significant differentiators. Using SVM, the highest accuracy (0.96) was achieved from a single feature (mean of RED), or from three feature combinations of IVIM or ADC. Combining features from all models gave perfect classification. No single feature predicted HER2 status of ER + tumors (univariate or SVM), although high accuracy (0.90) was achieved with SVM combining several features. Importantly, these features had to include higher-order statistics (kurtosis and skewness), indicating the importance to account for heterogeneity. Our findings suggest that SVM, using features from a combination of diffusion models, improves prediction accuracy for differentiation of benign versus malignant breast tumors, and may further assist in subtyping of breast cancer. 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1205-1216. © 2017 International Society for Magnetic Resonance in Medicine.

A comparison of multivariate and univariate time series approaches to modelling and forecasting emergency department demand in Western Australia.

PubMed

Aboagye-Sarfo, Patrick; Mai, Qun; Sanfilippo, Frank M; Preen, David B; Stewart, Louise M; Fatovich, Daniel M

2015-10-01

To develop multivariate vector-ARMA (VARMA) forecast models for predicting emergency department (ED) demand in Western Australia (WA) and compare them to the benchmark univariate autoregressive moving average (ARMA) and Winters' models. Seven-year monthly WA state-wide public hospital ED presentation data from 2006/07 to 2012/13 were modelled. Graphical and VARMA modelling methods were used for descriptive analysis and model fitting. The VARMA models were compared to the benchmark univariate ARMA and Winters' models to determine their accuracy to predict ED demand. The best models were evaluated by using error correction methods for accuracy. Descriptive analysis of all the dependent variables showed an increasing pattern of ED use with seasonal trends over time. The VARMA models provided a more precise and accurate forecast with smaller confidence intervals and better measures of accuracy in predicting ED demand in WA than the ARMA and Winters' method. VARMA models are a reliable forecasting method to predict ED demand for strategic planning and resource allocation. While the ARMA models are a closely competing alternative, they under-estimated future ED demand. Copyright © 2015 Elsevier Inc. All rights reserved.

A Unified Framework for Association Analysis with Multiple Related Phenotypes

PubMed Central

Stephens, Matthew

2013-01-01

We consider the problem of assessing associations between multiple related outcome variables, and a single explanatory variable of interest. This problem arises in many settings, including genetic association studies, where the explanatory variable is genotype at a genetic variant. We outline a framework for conducting this type of analysis, based on Bayesian model comparison and model averaging for multivariate regressions. This framework unifies several common approaches to this problem, and includes both standard univariate and standard multivariate association tests as special cases. The framework also unifies the problems of testing for associations and explaining associations – that is, identifying which outcome variables are associated with genotype. This provides an alternative to the usual, but conceptually unsatisfying, approach of resorting to univariate tests when explaining and interpreting significant multivariate findings. The method is computationally tractable genome-wide for modest numbers of phenotypes (e.g. 5–10), and can be applied to summary data, without access to raw genotype and phenotype data. We illustrate the methods on both simulated examples, and to a genome-wide association study of blood lipid traits where we identify 18 potential novel genetic associations that were not identified by univariate analyses of the same data. PMID:23861737

Organizational downsizing and age discrimination litigation: the influence of personnel practices and statistical evidence on litigation outcomes.

PubMed

Wingate, Peter H; Thornton, George C; McIntyre, Kelly S; Frame, Jennifer H

2003-02-01

The present study examined relationships between reduction-in-force (RIF) personnel practices, presentation of statistical evidence, and litigation outcomes. Policy capturing methods were utilized to analyze the components of 115 federal district court opinions involving age discrimination disparate treatment allegations and organizational downsizing. Univariate analyses revealed meaningful links between RIF personnel practices, use of statistical evidence, and judicial verdict. The defendant organization was awarded summary judgment in 73% of the claims included in the study. Judicial decisions in favor of the defendant organization were found to be significantly related to such variables as formal performance appraisal systems, termination decision review within the organization, methods of employee assessment and selection for termination, and the presence of a concrete layoff policy. The use of statistical evidence in ADEA disparate treatment litigation was investigated and found to be a potentially persuasive type of indirect evidence. Legal, personnel, and evidentiary ramifications are reviewed, and a framework of downsizing mechanics emphasizing legal defensibility is presented.

Multivariate pattern analysis of fMRI data reveals deficits in distributed representations in schizophrenia

PubMed Central

Yoon, Jong H.; Tamir, Diana; Minzenberg, Michael J.; Ragland, J. Daniel; Ursu, Stefan; Carter, Cameron S.

2009-01-01

Background Multivariate pattern analysis is an alternative method of analyzing fMRI data, which is capable of decoding distributed neural representations. We applied this method to test the hypothesis of the impairment in distributed representations in schizophrenia. We also compared the results of this method with traditional GLM-based univariate analysis. Methods 19 schizophrenia and 15 control subjects viewed two runs of stimuli--exemplars of faces, scenes, objects, and scrambled images. To verify engagement with stimuli, subjects completed a 1-back matching task. A multi-voxel pattern classifier was trained to identify category-specific activity patterns on one run of fMRI data. Classification testing was conducted on the remaining run. Correlation of voxel-wise activity across runs evaluated variance over time in activity patterns. Results Patients performed the task less accurately. This group difference was reflected in the pattern analysis results with diminished classification accuracy in patients compared to controls, 59% and 72% respectively. In contrast, there was no group difference in GLM-based univariate measures. In both groups, classification accuracy was significantly correlated with behavioral measures. Both groups showed highly significant correlation between inter-run correlations and classification accuracy. Conclusions Distributed representations of visual objects are impaired in schizophrenia. This impairment is correlated with diminished task performance, suggesting that decreased integrity of cortical activity patterns is reflected in impaired behavior. Comparisons with univariate results suggest greater sensitivity of pattern analysis in detecting group differences in neural activity and reduced likelihood of non-specific factors driving these results. PMID:18822407

Transportation Workload Forecasting (TWF) Study.

DTIC Science & Technology

1984-01-01

inflation factors, changes in troop strengths; opening , closing, or consolidation of facilities; and changes in mode of transportation. (4) The Military...tons Initial attempts to read the data with a univariate statistics program failed, due to the existence of nonnumeric entries in data fields . Records...W M=wn.99,i.i.Pm.i-,9Nd.~ C;f* ne hJN lfr csN ewc S.-,n melt rlfMOMf7 . £9 V oocacooofll.O N trtoati9e ieonhnfbo£0 * **. .~ ~~~ ~~~~ n

Game Location and Team Quality Effects on Performance Profiles in Professional Soccer

PubMed Central

Lago-Peñas, Carlos; Lago-Ballesteros, Joaquin

2011-01-01

Home advantage in team sports has an important role in determining the outcome of a game. The aim of the present study was to identify the soccer game- related statistics that best discriminate home and visiting teams according to the team quality. The sample included all 380 games of the Spanish professional men’s league. The independent variables were game location (home or away) and the team quality. Teams were classified into four groups according to their final ranking at the end of the league. The game-related statistics registered were divided into three groups: (i) variables related to goals scored; (ii) variables related to offense and (iii) variables related to defense. A univariate (t-test and Mann-Whitney U) and multivariate (discriminant analysis) analysis of data was done. Results showed that home teams have significantly higher means for goal scored, total shots, shots on goal, attacking moves, box moves, crosses, offsides committed, assists, passes made, successful passes, dribbles made, successful dribbles, ball possession, and gains of possession, while visiting teams presented higher means for losses of possession and yellow cards. In addition, the findings of the current study confirm that game location and team quality are important in determining technical and tactical performances in matches. Teams described as superior and those described as inferior did not experience the same home advantage. Future research should consider the influence of other confounding variables such as weather conditions, game status and team form. Key points Home teams have significantly higher figures for attack indicators probably due to facilities familiarity and crowd effects. The teams’ game-related statistics profile varied according to game location and team quality. Teams described as superior and those described as inferior did not experience the same home advantage. PMID:24150619

Degree-based statistic and center persistency for brain connectivity analysis.

PubMed

Yoo, Kwangsun; Lee, Peter; Chung, Moo K; Sohn, William S; Chung, Sun Ju; Na, Duk L; Ju, Daheen; Jeong, Yong

2017-01-01

Brain connectivity analyses have been widely performed to investigate the organization and functioning of the brain, or to observe changes in neurological or psychiatric conditions. However, connectivity analysis inevitably introduces the problem of mass-univariate hypothesis testing. Although, several cluster-wise correction methods have been suggested to address this problem and shown to provide high sensitivity, these approaches fundamentally have two drawbacks: the lack of spatial specificity (localization power) and the arbitrariness of an initial cluster-forming threshold. In this study, we propose a novel method, degree-based statistic (DBS), performing cluster-wise inference. DBS is designed to overcome the above-mentioned two shortcomings. From a network perspective, a few brain regions are of critical importance and considered to play pivotal roles in network integration. Regarding this notion, DBS defines a cluster as a set of edges of which one ending node is shared. This definition enables the efficient detection of clusters and their center nodes. Furthermore, a new measure of a cluster, center persistency (CP) was introduced. The efficiency of DBS with a known "ground truth" simulation was demonstrated. Then they applied DBS to two experimental datasets and showed that DBS successfully detects the persistent clusters. In conclusion, by adopting a graph theoretical concept of degrees and borrowing the concept of persistence from algebraic topology, DBS could sensitively identify clusters with centric nodes that would play pivotal roles in an effect of interest. DBS is potentially widely applicable to variable cognitive or clinical situations and allows us to obtain statistically reliable and easily interpretable results. Hum Brain Mapp 38:165-181, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Analysis and evaluation of the effectiveness of epidural analgesia and its relationship with eutocic or dystocic delivery.

PubMed

Sánchez-Migallón, V; Sánchez, E; Raynard, M; Miranda, A; Borràs, R M

Numerous studies have demonstrated the difference in the verbal rating scale with regard to obstructed labour and induced labour, so that obstructed labour and foetal macrosomia have been related to a greater sensation of pain during labour, particularly in the first stage. Even the epidural analgesia is linked to the need for instrumented or caesarean section due to foetal obstruction. The goal of the study is to analyze and evaluate the effectiveness of epidural analgesia in normal versus obstructed labour. One hundred and eighty pregnant women were included in an observational, analytical, longitudinal and prospective study, that was performed in the Obstetrics Department of the Hospital Universitario Dexeus. All the nulliparous or multiparous over 36 weeks of pregnancy, after 3cm of cervical dilatation in spontaneous or induced labor were included. All the patients were given epidural analgesia according to protocol. The basic descriptive methods were used for the univariate statistical analysis of the sample and the Mann-Whitney U test was used for the comparison of means between both groups. The correlations between variables were studied by means of the Spearman coefficient of correlation. The differences regarded as statistically significant are those whose P<.05. In our population there were no statistically significant differences in the effectiveness of epidural analgesia in normal versus obstructed labour. Patients who got epidural analgesia and had obstructed labors have the same degree of verbal rating scale as patients that do not had obstructed labors (P>.05). Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Novel biomarker identification using metabolomic profiling to differentiate radiation necrosis and recurrent tumor following Gamma Knife radiosurgery.

PubMed

Lu, Alex Y; Turban, Jack L; Damisah, Eyiyemisi C; Li, Jie; Alomari, Ahmed K; Eid, Tore; Vortmeyer, Alexander O; Chiang, Veronica L

2017-08-01

OBJECTIVE Following an initial response of brain metastases to Gamma Knife radiosurgery, regrowth of the enhancing lesion as detected on MRI may represent either radiation necrosis (a treatment-related inflammatory change) or recurrent tumor. Differentiation of radiation necrosis from tumor is vital for management decision making but remains difficult by imaging alone. In this study, gas chromatography with time-of-flight mass spectrometry (GC-TOF) was used to identify differential metabolite profiles of the 2 tissue types obtained by surgical biopsy to find potential targets for noninvasive imaging. METHODS Specimens of pure radiation necrosis and pure tumor obtained from patient brain biopsies were flash-frozen and validated histologically. These formalin-free tissue samples were then analyzed using GC-TOF. The metabolite profiles of radiation necrosis and tumor samples were compared using multivariate and univariate statistical analysis. Statistical significance was defined as p ≤ 0.05. RESULTS For the metabolic profiling, GC-TOF was performed on 7 samples of radiation necrosis and 7 samples of tumor. Of the 141 metabolites identified, 17 (12.1%) were found to be statistically significantly different between comparison groups. Of these metabolites, 6 were increased in tumor, and 11 were increased in radiation necrosis. An unsupervised hierarchical clustering analysis found that tumor had elevated levels of metabolites associated with energy metabolism, whereas radiation necrosis had elevated levels of metabolites that were fatty acids and antioxidants/cofactors. CONCLUSIONS To the authors' knowledge, this is the first tissue-based metabolomics study of radiation necrosis and tumor. Radiation necrosis and recurrent tumor following Gamma Knife radiosurgery for brain metastases have unique metabolite profiles that may be targeted in the future to develop noninvasive metabolic imaging techniques.

Full-text publication of abstracts presented at European Orthodontic Society congresses.

PubMed

Livas, Christos; Pandis, Nikolaos; Ren, Yijin

2014-10-01

Empirical evidence has indicated that only a subsample of studies conducted reach full-text publication and this phenomenon has become known as publication bias. A form of publication bias is the selectively delayed full publication of conference abstracts. The objective of this article was to examine the publication status of oral abstracts and poster-presentation abstracts, included in the scientific program of the 82nd and 83rd European Orthodontic Society (EOS) congresses, held in 2006 and 2007, and to identify factors associated with full-length publication. A systematic search of PubMed and Google Scholar databases was performed in April 2013 using author names and keywords from the abstract title to locate abstract and full-article publications. Information regarding mode of presentation, type of affiliation, geographical origin, statistical results, and publication details were collected and analyzed using univariable and multivariable logistic regression. Approximately 51 per cent of the EOS 2006 and 55 per cent of the EOS 2007 abstracts appeared in print more than 5 years post congress. A mean period of 1.32 years elapsed between conference and publication date. Mode of presentation (oral or poster), use of statistical analysis, and research subject area were significant predictors for publication success. Inherent discrepancies of abstract reporting, mainly related to presentation of preliminary results and incomplete description of methods, may be considered in analogous studies. On average 52.2 per cent of the abstracts presented at the two EOS conferences reached full publication. Abstracts presented orally, including statistical analysis, were more likely to get published. © The Author 2013. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Clinical evaluation of the aberrant left hepatic artery arising from the left gastric artery in esophagectomy.

PubMed

Maki, Harufumi; Satodate, Hitoshi; Satou, Shouichi; Nakajima, Kentaro; Nagao, Atsuki; Watanabe, Kazuteru; Nara, Satoshi; Furushima, Kaoru; Harihara, Yasushi

2018-04-12

The left gastric artery (LGA) is commonly severed when the gastric tube is made for esophageal reconstruction. Sacrifice of the LGA can cause liver ischemic necrosis in patients with an aberrant left hepatic artery (ALHA) arising from the LGA. We experienced a case of life-threatening hepatic abscess after severing the ALHA. Therefore, the purpose of this study is to evaluate clinical outcomes of severing the ALHA. We retrospectively enrolled 176 consecutive patients who underwent esophagectomy with gastric tube reconstruction. They were classified into the ALHA (N = 16, 9.1%) and non-ALHA (N = 160, 90.9%) groups. Univariate analysis was performed to compare the clinicopathological variables. Long-term survival was analyzed using the Kaplan-Meier method in matched pair case-control analysis. The postoperative morbidities were not statistically different between the two groups, although serum alanine aminotransferase levels on postoperative days 1 and 3 were significantly higher in the ALHA group (36 IU/L, 14-515; 32 IU/L, 13-295) than in the non-ALHA group (24 IU/L, 8-163; 19 IU/L, 6-180), respectively (p = 0.0055; p = 0.0073). Overall survival was not statistically different between the two groups (p = 0.26). Severe hepatic abscess occurred in 6.3% of the patients with the ALHA after esophagectomy, even though the results presented here found no statistical differences in morbidity or mortality with or without the ALHA. Surgeons should probably attempt to preserve the ALHA especially in patients with altered liver function while making a gastric tube for esophageal reconstruction.

Medicaid Managed Care Structures and Care Coordination.

PubMed

Gilchrist-Scott, Douglas H; Feinstein, James A; Agrawal, Rishi

2017-09-01

Child enrollment in Medicaid managed care (MMC) has expanded dramatically, primarily through state mandates. Care coordination is a key metric in MMC evaluation because it drives much of the proposed cost savings and may be associated with improved health outcomes and utilization. We evaluated the relationships between enrollment in 2 MMC structures, primary care case management (PCCM) and health maintenance organization (HMO) and access to and receipt of care coordination by children. Using data from the 2011/2012 National Survey of Children's Health and the Medicaid Statistical Information System state data mart, we conducted a retrospective, cross-sectional analysis of the relationships between fee-for-service, PCCM or HMO enrollment, and access to and receipt of care coordination. State-level univariate analyses and individual and state multilevel multivariable analyses evaluated correlations between MMC enrollment and care coordination, controlling for demographic characteristics and state financing levels. In univariate and multilevel multivariable analyses, the PCCM penetration rate was significantly associated with increased access to care coordination (adjusted odds ratio: 1.23, P = .034) and receipt of care coordination (adjusted odds ratio: 1.37, P = .02). The HMO penetration rate was significantly associated with lower access to care coordination (adjusted odds ratio: 0.85, P = .05) and receipt of care coordination (adjusted odds ratio: 0.71, P < .001). Fee-for-service served as the referent. State utilization of MMC varied widely. These data suggest that care coordination may be more effective in PCCM than HMO structures. States should consider care coordination outcomes when structuring their Medicaid programs. Copyright © 2017 by the American Academy of Pediatrics.

The impact of sample size on the reproducibility of voxel-based lesion-deficit mappings.

PubMed

Lorca-Puls, Diego L; Gajardo-Vidal, Andrea; White, Jitrachote; Seghier, Mohamed L; Leff, Alexander P; Green, David W; Crinion, Jenny T; Ludersdorfer, Philipp; Hope, Thomas M H; Bowman, Howard; Price, Cathy J

2018-07-01

This study investigated how sample size affects the reproducibility of findings from univariate voxel-based lesion-deficit analyses (e.g., voxel-based lesion-symptom mapping and voxel-based morphometry). Our effect of interest was the strength of the mapping between brain damage and speech articulation difficulties, as measured in terms of the proportion of variance explained. First, we identified a region of interest by searching on a voxel-by-voxel basis for brain areas where greater lesion load was associated with poorer speech articulation using a large sample of 360 right-handed English-speaking stroke survivors. We then randomly drew thousands of bootstrap samples from this data set that included either 30, 60, 90, 120, 180, or 360 patients. For each resample, we recorded effect size estimates and p values after conducting exactly the same lesion-deficit analysis within the previously identified region of interest and holding all procedures constant. The results show (1) how often small effect sizes in a heterogeneous population fail to be detected; (2) how effect size and its statistical significance varies with sample size; (3) how low-powered studies (due to small sample sizes) can greatly over-estimate as well as under-estimate effect sizes; and (4) how large sample sizes (N ≥ 90) can yield highly significant p values even when effect sizes are so small that they become trivial in practical terms. The implications of these findings for interpreting the results from univariate voxel-based lesion-deficit analyses are discussed. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Patient Perceptions of Athletic Trainers and Orthopaedic Medical Residents as Primary Clinical Support Staff in Sports Medicine Practice: A Randomized, Double-Blinded Prospective Survey.

PubMed

Pecha, Forrest Q; Nicolello, Timothy S; Xerogeanes, John W; Karas, Spero; Labib, Sameh A

2015-01-01

Orthopaedic sports medicine practices utilize a variety of healthcare professionals to assist physicians in the clinic. The purpose of this study was to investigate patients' perception of orthopaedic knowledge and clinical care provided by orthopaedic medical residents and athletic trainers (ATs). ATs will be perceived similarly to orthopaedic medical residents in overall patient care and perceived education level. Randomized, double-blind survey. 2. New patients were randomly selected to receive the survey to complete during an office visit. The survey included 8 questions which rated the patient's perceived level of orthopaedic knowledge and level of patient care provided by the AT and orthopaedic medical residents. A total of 110 surveys were collected during the 2-year study period. The data were analyzed using a multivariate analysis of variance (MANOVA). The multivariate effect (Pillai's trace) was not significant between clinicians, F(8,111)=0.122, p=0.695, partial η2=0.106. Univariate tests showed a significance between patient perceived level of clinician education, F(1,118)=5.361, p=0.632, partial η2=0.043. Univariate test showed no significant differences on any other dependent variables. There is no evidence that patients' perception is different when comparing ATs and orthopaedic medical residents in orthopaedic knowledge and clinical care. Although a statistically significant difference was found in the perceived highest level of education attained, orthopaedic medical residents and ATs were each perceived to have a master's degree level of education. Physicians should continue to use ATs in their practices.

Sex estimation standards for medieval and contemporary Croats

PubMed Central

Bašić, Željana; Kružić, Ivana; Jerković, Ivan; Anđelinović, Deny; Anđelinović, Šimun

2017-01-01

Aim To develop discriminant functions for sex estimation on medieval Croatian population and test their application on contemporary Croatian population. Methods From a total of 519 skeletons, we chose 84 adult excellently preserved skeletons free of antemortem and postmortem changes and took all standard measurements. Sex was estimated/determined using standard anthropological procedures and ancient DNA (amelogenin analysis) where pelvis was insufficiently preserved or where sex morphological indicators were not consistent. We explored which measurements showed sexual dimorphism and used them for developing univariate and multivariate discriminant functions for sex estimation. We included only those functions that reached accuracy rate ≥80%. We tested the applicability of developed functions on modern Croatian sample (n = 37). Results From 69 standard skeletal measurements used in this study, 56 of them showed statistically significant sexual dimorphism (74.7%). We developed five univariate discriminant functions with classification rate 80.6%-85.2% and seven multivariate discriminant functions with an accuracy rate of 81.8%-93.0%. When tested on the modern population functions showed classification rates 74.1%-100%, and ten of them reached aimed accuracy rate. Females showed higher classification rates in the medieval populations, whereas males were better classified in the modern populations. Conclusion Developed discriminant functions are sufficiently accurate for reliable sex estimation in both medieval Croatian population and modern Croatian samples and may be used in forensic settings. The methodological issues that emerged regarding the importance of considering external factors in development and application of discriminant functions for sex estimation should be further explored. PMID:28613039

Quality of life outcomes in patients living with stoma.

PubMed

Anaraki, Fakhrialsadat; Vafaie, Mohamad; Behboo, Roobic; Maghsoodi, Nakisa; Esmaeilpour, Sahar; Safaee, Azadeh

2012-09-01

Despite efforts to maintain the intestinal tissue and treat gastrointestinal disease, a large number of patients undergo ostomy surgery each year. Using stoma reduces the patient's quality of life (QOL) greatly. Although there are approximately 3000 patients in Iran; there is little information about the impact of stoma on their QOL. The study aims to evaluate QOL of stoma patients using a special measurement tool. This survey was a cross-sectional study that was conducted on 102 random samples of stoma patients. The City of Hope Quality of Life-Ostomy Questionnaire was used for collecting demographic and clinical information and evaluating QOL. Univariate and multiple regression analyses were performed to identify predictors of QOL. The mean score for the overall QOL for stoma patients was 7.48 ± 0.9. 70% of patients were dissatisfied with sexual activities. More than half of them reported feelings of depression following stoma surgery. Univariate analysis indicated that factors such as the type of ostomy (temporary/permanent), the underlying disease that had led to the stoma, depression, problem with location of ostomy, and change in clothing style had significant effects on overall QOL and its subscales (P < 0.05). The results of the regression analyses showed that only depression and problem with the location of ostomy were statistically significant in predicting patients' QOL and its subscales (P < 0.05). The findings demonstrated that living with stoma influences the overall aspect of QOL. Education for the patients and their families is important for improving the stoma patients' QOL. Sexual and psychological consultation may also improve patients' QOL.

Statistical Exposé of a Multiple-Compartment Anaerobic Reactor Treating Domestic Wastewater.

PubMed

Pfluger, Andrew R; Hahn, Martha J; Hering, Amanda S; Munakata-Marr, Junko; Figueroa, Linda

2018-06-01

  Mainstream anaerobic treatment of domestic wastewater is a promising energy-generating treatment strategy; however, such reactors operated in colder regions are not well characterized. Performance data from a pilot-scale, multiple-compartment anaerobic reactor taken over 786 days were subjected to comprehensive statistical analyses. Results suggest that chemical oxygen demand (COD) was a poor proxy for organics in anaerobic systems as oxygen demand from dissolved inorganic material, dissolved methane, and colloidal material influence dissolved and particulate COD measurements. Additionally, univariate and functional boxplots were useful in visualizing variability in contaminant concentrations and identifying statistical outliers. Further, significantly different dissolved organic removal and methane production was observed between operational years, suggesting that anaerobic reactor systems may not achieve steady-state performance within one year. Last, modeling multiple-compartment reactor systems will require data collected over at least two years to capture seasonal variations of the major anaerobic microbial functions occurring within each reactor compartment.

Nonparametric entropy estimation using kernel densities.

PubMed

Lake, Douglas E

2009-01-01

The entropy of experimental data from the biological and medical sciences provides additional information over summary statistics. Calculating entropy involves estimates of probability density functions, which can be effectively accomplished using kernel density methods. Kernel density estimation has been widely studied and a univariate implementation is readily available in MATLAB. The traditional definition of Shannon entropy is part of a larger family of statistics, called Renyi entropy, which are useful in applications that require a measure of the Gaussianity of data. Of particular note is the quadratic entropy which is related to the Friedman-Tukey (FT) index, a widely used measure in the statistical community. One application where quadratic entropy is very useful is the detection of abnormal cardiac rhythms, such as atrial fibrillation (AF). Asymptotic and exact small-sample results for optimal bandwidth and kernel selection to estimate the FT index are presented and lead to improved methods for entropy estimation.

Water pipe (shisha) smoking and associated factors among Malaysian university students.

PubMed

Al-Naggar, Redhwan Ahmed; Saghir, Fatma S A

2011-01-01

The objective of this study was to determine the prevalence of waterpipe (shisha) smoking and associated factors among Malaysian university students. A total of 200 university students from Management and Science University participated in this study. The survey was conducted by simple random sampling by randomly distributing self-administered questionnaires to the library, cafeterias and classes. The protocol of this study was approved by the ethics committee of Management and Science University. Consent forms were obtained from the students before they answered the questionnaire. Statistical analyses were performed using the Statistical Package for Social Science (SPSS) version 13. with the Student's t-test for comparison of the mean practice and backward multiple linear regression for multivariate analysis. The majority of the subjects were male, single, Malay and from urban areas (61.5%, 94.5%, 66%, 76.5%; respectively). In this study 30% of the study participants were shisha smokers. Regarding knowledge about shisha smoking, the majority (48.5%) mentioned that shisha is less harmful than cigarettes and 55% reported that shisha is less addictive. Univariate analysis showed that age, race, sex and income significantly influenced the practice of smoking shisha among university students (p=0.019, p=0.002, p=0.001, p=0.018; respectively). For multivariate analysis, income and gender demonstrated significant influence (both p=0.001). There was a high prevalence of shisha smoking among Malaysian university students and knowledge about the dangers is low. Income and gender significantly influenced the practice of smoking shisha in our population. Banning of smoking including shisha smoking in public places is strongly recommended.

Factors that Affected Functional Outcome After a Delayed Excision and Split-Thickness Skin Graft on the Dorsal Side of Burned Hands.

PubMed

Shichinohe, Ryuji; Yamamoto, Yuhei; Kawashima, Kunihiro; Kimura, Chu; Ono, Kentaro; Horiuchi, Katsumi; Yoshida, Tetsunori; Murao, Naoki; Hayashi, Toshihiko; Funayama, Emi; Oyama, Akihiko; Furukawa, Hiroshi

Early excision and skin grafting is the principle treatment for a burned hand although there are occasions when it cannot be done such as severe general condition, delayed consultation, and the lack of a definitive assessment of burn depth. This study analyzes the factors that affected function after a delayed excision and skin graft for hands with a deep dermal burn. This study retrospectively evaluated 43 burned hands that required a delayed excision and split-thickness skin graft on the dorsal side. Cases were required to only have split-thickness skin grafting from the dorsum of the hand and fingers distally to at least the proximal interphalangeal joint at least 8 days after the injury. The hands were divided into two functional categories: Functional category A, normal or nearly normal joint movements, and functional category B, abnormal joint movements. Demographic data were assessed statistically by a univariate analysis following a multiple regression analysis by a stepwise selection. A significant difference was observed between the groups in the number of days from grafting to complete wound healing of the graft site and with or without an escharotomy in the analysis. These parameters were statistically significant predictors of functional category B. The functional outcome of a burned hand after a delayed excision and split-thickness skin graft on the dorsal side became degraded depending on the number of days from grafting to complete wound healing. Cases that underwent an escharotomy also showed deterioration in function.

[Risk factors for the kidney stones: a hospital-based case-control study in a distric hospital in Beijing].

PubMed

Wang, Jiao; Luo, Gong-tang; Niu, Wei-jing; Gong, Man-man; Liu, Lu; Zhou, Jie; Zhou, Xue-wei; He, Li-hua

2013-12-18

To explore the risk and protective factors of kidney calculi in order to put forward theoretical basis for preventive and control measures. A 1:1 matched case-control study was performed using data from a hospital in Beijing. The case group included 100 inpatients who were diagnosed kidney calculi using B ultrasonic, X-ray and intravenous pyelography during the survey while other 100 urolithiasis and endocrine disease excluded inpatients who shared the same sex, within five years gap to the case group inpatients were for the control group. A face-to-face survey was conducted with self-made questionnaires which covered demographic characteristics, water issues, dietary habits, genetic and medical history. Epidata 3.0 was used to build the database and SPSS 19.0 for the statistical analysis. In the univariate Logistic regression analysis, ten variables were found showing statistical significance. For the multivariate Logistic regression analysis, variables left in the model were labor intensity (OR=0.622, 95%CI: 0.435-0.889), preferring to drink after dinner (OR=0.316, 95%CI: 0.122-0.815), loving drinking (OR=0.232, 95%CI: 0.084-0.642), drinking tea regularly (OR=1.463, 95%CI: 1.033-2.071), eating more vegetables (OR=0.571, 95%CI: 0.328-0.993), the history of the urolithiasis (OR=2.127, 95%CI: 1.065-90.145). Drinking tea regularly, urolithiasis history and brain work are the risk factors of kidney calculi while loving drinking and eating more vegetables for the protection.

Cigarette smoking and health-promoting behaviours among tuberculosis patients in rural areas.

PubMed

Tsai, Shu-Lan; Lai, Chun-Liang; Chi, Miao-Ching; Chen, Mei-Yen

2016-09-01

To explore cigarette smoking and health-promoting behaviours among disadvantaged adults before their tuberculosis diagnosis and after their tuberculosis treatment. Although tuberculosis infection is associated with impaired immune function, healthy lifestyle habits can play a role in improving the immune system. However, limited research has explored the health-promoting behaviours and cigarette smoking habits among tuberculosis patients in Taiwan. A cross-sectional retrospective study with a convenience sample. This study was conducted between May 2013-June 2014 with 123 patients at a rural district hospital in Chiayi County, Taiwan. Statistical analyses included descriptive statistics, univariate analysis and stepwise regression analysis. Tuberculosis tended to be associated with less education, male sex, malnutrition, cigarette smoking and unhealthy lifestyle habits before the tuberculosis diagnosis. The percentage of smoking decreased from 46·9% before to 30·2% after the tuberculosis diagnosis. Body mass index and health-promoting behaviours also significantly improved after tuberculosis treatment. After controlling for potential confounding factors, multivariate analysis identified chronic disease and completed treatment as significant factors that were associated with current health-promoting behaviours. A high prevalence of cigarette smoking and low levels of health-promoting behaviours were observed before the diagnosis and during or after completing tuberculosis treatment. This study's findings indicate the importance of promoting healthy lifestyle changes among tuberculosis patients; aggressive measures should be implemented immediately after the first diagnosis of tuberculosis. Furthermore, health promotion and smoking cessation programmes should be initiated in the general population to prevent activation of latent tuberculosis infection, and these programmes should specifically target men and rural residents. © 2016 John Wiley & Sons Ltd.

Impact of Donor Arterial Partial Pressure of Oxygen on Outcomes After Lung Transplantation in Adult Cystic Fibrosis Recipients.

PubMed

Hayes, Don; Kopp, Benjamin T; Kirkby, Stephen E; Reynolds, Susan D; Mansour, Heidi M; Tobias, Joseph D; Tumin, Dmitry

2016-08-01

Donor PaO2 levels are used for assessing organs for lung transplantation (LTx), but survival implications of PaO2 levels in adult cystic fibrosis (CF) patients receiving LTx are unclear. UNOS registry data spanning 2005-2013 were used to test for associations of donor PaO2 with patient survival and bronchiolitis obliterans syndrome (BOS) in adult (age ≥ 18 years) first-time LTx recipients diagnosed with CF. The analysis included 1587 patients, of whom 1420 had complete data for multivariable Cox models. No statistically significant differences among donor PaO2 categories of ≤200, 201-300, 301-400, or >400 mmHg were found in univariate survival analysis (log-rank test p = 0.290). BOS onset did not significantly differ across donor PaO2 categories (Chi-square p = 0.480). Multivariable Cox models of patient survival supported the lack of difference across donor PaO2 categories. Interaction analysis found a modest difference in survival between the two top categories of donor PaO2 when examining patients with body mass index (BMI) in the lowest decile (≤16.5 kg/m(2)). Donor PaO2 was not associated with survival or BOS onset in adult CF patients undergoing LTx. Notwithstanding statistically significant interactions between donor PaO2 and BMI, there was no evidence of post-LTx survival risk associated with donor PaO2 below conventional thresholds in any subgroup of adults with CF.

Glycolytic activity in breast cancer using 18F-FDG PET/CT as prognostic predictor: A molecular phenotype approach.

PubMed

Garcia Vicente, A M; Soriano Castrejón, A; Amo-Salas, M; Lopez Fidalgo, J F; Muñoz Sanchez, M M; Alvarez Cabellos, R; Espinosa Aunion, R; Muñoz Madero, V

2016-01-01

To explore the relationship between basal (18)F-FDG uptake in breast tumors and survival in patients with breast cancer (BC) using a molecular phenotype approach. This prospective and multicentre study included 193 women diagnosed with BC. All patients underwent an (18)F-FDG PET/CT prior to treatment. Maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N), and the N/T index was obtained in all the cases. Metabolic stage was established. As regards biological prognostic parameters, tumors were classified into molecular sub-types and risk categories. Overall survival (OS) and disease free survival (DFS) were obtained. An analysis was performed on the relationship between semi-quantitative metabolic parameters with molecular phenotypes and risk categories. The effect of molecular sub-type and risk categories in prognosis was analyzed using Kaplan-Meier and univariate and multivariate tests. Statistical differences were found in both SUVT and SUVN, according to the molecular sub-types and risk classifications, with higher semi-quantitative values in more biologically aggressive tumors. No statistical differences were observed with respect to the N/T index. Kaplan-Meier analysis revealed that risk categories were significantly related to DFS and OS. In the multivariate analysis, metabolic stage and risk phenotype showed a significant association with DFS. High-risk phenotype category showed a worst prognosis with respect to the other categories with higher SUVmax in primary tumor and lymph nodes. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Clinicians' adherence to clinical practice guidelines for cardiac function monitoring during antipsychotic treatment: a retrospective report on 434 patients with severe mental illness.

PubMed

Manchia, Mirko; Firinu, Giorgio; Carpiniello, Bernardo; Pinna, Federica

2017-03-31

Severe mental illness (SMI) has considerable excess morbidity and mortality, a proportion of which is explained by cardiovascular diseases, caused in part by antipsychotic (AP) induced QT-related arrhythmias and sudden death by Torsade de Point (TdP). The implementation of evidence-based recommendations for cardiac function monitoring might reduce the incidence of these AP-related adverse events. To investigate clinicians' adherence to cardiac function monitoring before and after starting AP, we performed a retrospective assessment of 434 AP-treated SMI patients longitudinally followed-up for 5 years at an academic community mental health center. We classified antipsychotics according to their risk of inducing QT-related arrhythmias and TdP (Center for Research on Therapeutics, University of Arizona). We used univariate tests and multinomial or binary logistic regression model for data analysis. Univariate and multinomial regression analysis showed that psychiatrists were more likely to perform pre-treatment electrocardiogram (ECG) and electrolyte testing with AP carrying higher cardiovascular risk, but not on the basis of AP pharmacological class. Univariate and binomial regression analysis showed that cardiac function parameters (ECG and electrolyte balance) were more frequently monitored during treatment with second generation AP than with first generation AP. Our data show the presence of weaknesses in the cardiac function monitoring of AP-treated SMI patients, and might guide future interventions to tackle them.

The International Scoring System (ISS) for multiple myeloma remains a robust prognostic tool independently of patients' renal function.

PubMed

Dimopoulos, M A; Kastritis, E; Michalis, E; Tsatalas, C; Michael, M; Pouli, A; Kartasis, Z; Delimpasi, S; Gika, D; Zomas, A; Roussou, M; Konstantopoulos, K; Parcharidou, A; Zervas, K; Terpos, E

2012-03-01

The International Staging System (ISS) is the most widely used staging system for patients with multiple myeloma (MM). However, serum β2-microglobulin increases in renal impairment (RI) and there have been concerns that ISS-3 stage may include 'up-staged' MM patients in whom elevated β2-microglobulin reflects the degree of renal dysfunction rather than tumor load. In order to assess the impact of RI on the prognostic value of ISS, we analyzed 1516 patients with symptomatic MM and the degree of RI was classified according to the Kidney Disease Outcomes Quality Initiative-Chronic Kidney Disease (CKD) criteria. Forty-eight percent patients had stages 3-5 CKD while 29% of patients had ISS-1, 38% had ISS-2 and 33% ISS-3. The frequency and severity of RI were more common in ISS-3 patients. RI was associated with inferior survival in univariate but not in multivariate analysis. When analyzed separately, ISS-1 and ISS-2 patients with RI had inferior survival in univariate but not in multivariate analysis. In ISS-3 MM patients, RI had no prognostic impact either in univariate or multivariate analysis. Results were similar, when we analyzed only patients with Bence-Jones >200 mg/day. ISS remains unaffected by the degree of RI, even in patients with ISS-3, which includes most patients with renal dysfunction.

Can the new RCP R0/R1 classification predict the clinical outcome in ductal adenocarcinoma of the pancreatic head?

PubMed

Janot, M S; Kersting, S; Belyaev, O; Matuschek, A; Chromik, A M; Suelberg, D; Uhl, W; Tannapfel, A; Bergmann, U

2012-08-01

According to the International Union Against Cancer (UICC), R1 is defined as the microscopic presence of tumor cells at the surface of the resection margin (RM). In contrast, the Royal College of Pathologists (RCP) suggested to declare R1 already when tumor cells are found within 1 mm of the RM. The aim of this study was to determine the significance of the RM concerning the prognosis of pancreatic ductal adenocarcinoma (PDAC). From 2007 to 2009, 62 patients underwent a curative operation for PDAC of the pancreatic head. The relevance of R status on cumulative overall survival (OS) was assessed on univariate and multivariate analysis for both the classic R classification (UICC) and the suggestion of the RCP. Following the UICC criteria, a positive RM was detected in 8 %. Along with grading and lymph node ratio, R status revealed a significant impact on OS on univariate and multivariate analysis. Applying the suggestion of the RCP, R1 rate rose to 26 % resulting in no significant impact on OS in univariate analysis. Our study has shown that the RCP suggestion for R status has no impact on the prognosis of PDAC. In contrast, our data confirmed the UICC R classification of RM as well as N category, grading, and lymph node ratio as significant prognostic factors.