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.

Radiation Therapy Noncompliance and Clinical Outcomes in an Urban Academic Cancer Center

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

Ohri, Nitin; Rapkin, Bruce D.; Guha, Chandan

Purpose: To examine associations between radiation therapy (RT) noncompliance and clinical outcomes. Methods and Materials: We reviewed all patients who completed courses of external beam RT with curative intent in our department from the years 2007 to 2012 for cancers of the head and neck, breast, lung, cervix, uterus, or rectum. Patients who missed 2 or more scheduled RT appointments (excluding planned treatment breaks) were deemed noncompliant. Univariate, multivariable, and propensity-matched analyses were performed to examine associations between RT noncompliance and clinical outcomes. Results: Of 1227 patients, 266 (21.7%) were noncompliant. With median follow-up of 50.9 months, 108 recurrences (8.8%) and 228more » deaths (18.6%) occurred. In univariate analyses, RT noncompliance was associated with increased recurrence risk (5-year cumulative incidence 16% vs 7%, P<.001), inferior recurrence-free survival (5-year actuarial rate 63% vs 79%, P<.001), and inferior overall survival (5-year actuarial rate 72% vs 83%, P<.001). In multivariable analyses that were adjusted for disease site and stage, comorbidity score, gender, ethnicity, race, and socioeconomic status (SES), RT noncompliance was associated with inferior recurrence, recurrence-free survival, and overall survival rates. Propensity score–matched models yielded results nearly identical to those seen in univariate analyses. Low SES was associated with RT noncompliance and was associated with inferior clinical outcomes in univariate analyses, but SES was not associated with inferior outcomes in multivariable models. Conclusion: For cancer patients being treated with curative intent, RT noncompliance is associated with inferior clinical outcomes. The magnitudes of these effects demonstrate that RT noncompliance can serve as a behavioral biomarker to identify high-risk patients who require additional interventions. Treatment compliance may mediate the associations that have been observed linking SES and clinical outcomes.« less

Multivariate Models for Normal and Binary Responses in Intervention Studies

ERIC Educational Resources Information Center

Pituch, Keenan A.; Whittaker, Tiffany A.; Chang, Wanchen

2016-01-01

Use of multivariate analysis (e.g., multivariate analysis of variance) is common when normally distributed outcomes are collected in intervention research. However, when mixed responses--a set of normal and binary outcomes--are collected, standard multivariate analyses are no longer suitable. While mixed responses are often obtained in…

A multivariate time series approach to modeling and forecasting demand in the emergency department.

PubMed

Jones, Spencer S; Evans, R Scott; Allen, Todd L; Thomas, Alun; Haug, Peter J; Welch, Shari J; Snow, Gregory L

2009-02-01

The goals of this investigation were to study the temporal relationships between the demands for key resources in the emergency department (ED) and the inpatient hospital, and to develop multivariate forecasting models. Hourly data were collected from three diverse hospitals for the year 2006. Descriptive analysis and model fitting were carried out using graphical and multivariate time series methods. Multivariate models were compared to a univariate benchmark model in terms of their ability to provide out-of-sample forecasts of ED census and the demands for diagnostic resources. Descriptive analyses revealed little temporal interaction between the demand for inpatient resources and the demand for ED resources at the facilities considered. Multivariate models provided more accurate forecasts of ED census and of the demands for diagnostic resources. Our results suggest that multivariate time series models can be used to reliably forecast ED patient census; however, forecasts of the demands for diagnostic resources were not sufficiently reliable to be useful in the clinical setting.

Hydrothermal contamination of public supply wells in Napa and Sonoma Valleys, California

USGS Publications Warehouse

Forrest, Matthew J.; Kulongoski, Justin T.; Edwards, Matthew S.; Farrar, Christopher D.; Belitz, Kenneth; Norris, Richard D.

2013-01-01

Groundwater chemistry and isotope data from 44 public supply wells in the Napa and Sonoma Valleys, California were determined to investigate mixing of relatively shallow groundwater with deeper hydrothermal fluids. Multivariate analyses including Cluster Analyses, Multidimensional Scaling (MDS), Principal Components Analyses (PCA), Analysis of Similarities (ANOSIM), and Similarity Percentage Analyses (SIMPER) were used to elucidate constituent distribution patterns, determine which constituents are significantly associated with these hydrothermal systems, and investigate hydrothermal contamination of local groundwater used for drinking water. Multivariate statistical analyses were essential to this study because traditional methods, such as mixing tests involving single species (e.g. Cl or SiO2) were incapable of quantifying component proportions due to mixing of multiple water types. Based on these analyses, water samples collected from the wells were broadly classified as fresh groundwater, saline waters, hydrothermal fluids, or mixed hydrothermal fluids/meteoric water wells. The Multivariate Mixing and Mass-balance (M3) model was applied in order to determine the proportion of hydrothermal fluids, saline water, and fresh groundwater in each sample. Major ions, isotopes, and physical parameters of the waters were used to characterize the hydrothermal fluids as Na–Cl type, with significant enrichment in the trace elements As, B, F and Li. Five of the wells from this study were classified as hydrothermal, 28 as fresh groundwater, two as saline water, and nine as mixed hydrothermal fluids/meteoric water wells. The M3 mixing-model results indicated that the nine mixed wells contained between 14% and 30% hydrothermal fluids. Further, the chemical analyses show that several of these mixed-water wells have concentrations of As, F and B that exceed drinking-water standards or notification levels due to contamination by hydrothermal fluids.

Changes in Landscape Greenness and Climatic Factors over ...

EPA Pesticide Factsheets

Monitoring and quantifying changes in vegetation cover over large areas using remote sensing can be achieved using the Normalized Difference Vegetation Index (NDVI), an indicator of greenness. However, distinguishing gradual shifts in NDVI (e.g. climate change) versus direct and rapid changes (e.g., fire, land development) is challenging as changes can be confounded by time-dependent patterns, and variation associated with climatic factors. In the present study we leveraged a method, that we previously developed for a pilot study, to address these confounding factors by evaluating NDVI change using autoregression techniques that compare results from univariate (NDVI vs. time) and multivariate analyses (NDVI vs. time and climatic factors) for ~7,660,636 1-km2 pixels comprising the 48 contiguous states of the USA, over a 25-year period (1989−2013). NDVI changed significantly for 48% of the nation over the 25-year in the univariate analyses where most significant trends (85%) indicated an increase in greenness over time. By including climatic factors in the multivariate analyses of NDVI over time, the detection of significant NDVI trends increased to 53% (an increase of 5%). Comparisons of univariate and multivariate analyses for each pixel showed that less than 4% of the pixels had a significant NDVI trend attributable to gradual climatic changes while the remainder of pixels with a significant NDVI trend indicated that changes were due to direct factors. Whi

Traditional food consumption and nutritional status of Dalit mothers in rural Andhra Pradesh, South India.

PubMed

Schmid, M A; Egeland, G M; Salomeyesudas, B; Satheesh, P V; Kuhnlein, H V

2006-11-01

To describe prevalence of malnutrition and their correlates of nutrient and traditional food consumption in rural Dalit mothers. In a cross-sectional study, we used socio-cultural questionnaires, anthropometric measurements and clinical eye examinations during the rainy season in 2003. Food frequency questionnaires and 24-h recalls were conducted during both summer and rainy seasons. Dalit mothers with young children were recruited from 37 villages in the Medak District of rural Andhra Pradesh, India. Dalit mothers (n = 220) participated. The prevalence of chronic energy-deficient (CED) mothers (body mass index <18.5 kg/m2) was 58%. Illiterate women and active women were more likely to have CED than those literate and non-active (relative risks (RR) = 1.6 and 1.4, respectively, P < or = 0.05), but literacy and activity level were not significant in multivariable analyses including sanitation and number of children < or =5 years of age. Increasing levels of fat intake, as a percent of total energy, was significantly associated with lower risk of CED (RR of the lowest 25th percentile compared to those in the 75th percentile or above was 1.6, P < or = 0.05), findings that remained significant in multivariable analyses. Consumption of pulses (g/day) was also inversely related to CED in univariate and multivariable analyses. Carbohydrate intake, as a percent of total energy, was inversely related to percent energy from fat (r = -0.96, P < or = 0.01), and, although positively related to CED in univariate analyses, carbohydrate consumption was not significant in multivariable analyses. Mothers' age in years and income was positively related to vitamin A deficiency. These results confirm that CED and vitamin A malnutrition among Dalit women are predominant problems in this area. Increased consumption of local traditional Dalit food (particularly sorghum, pulses, vegetables and animal source food) should be incorporated as an important component of intervention strategies to improve nutritional status.

Evaluating the role of admixture in cancer therapy via in vitro drug response and multivariate genome-wide associations

PubMed Central

Jack, John; Havener, Tammy M; McLeod, Howard L; Motsinger-Reif, Alison A; Foster, Matthew

2015-01-01

Aim: We investigate the role of ethnicity and admixture in drug response across a broad group of chemotherapeutic drugs. Also, we generate hypotheses on the genetic variants driving differential drug response through multivariate genome-wide association studies. Methods: Immortalized lymphoblastoid cell lines from 589 individuals (Hispanic or non-Hispanic/Caucasian) were used to investigate dose-response for 28 chemotherapeutic compounds. Univariate and multivariate statistical models were used to elucidate associations between genetic variants and differential drug response as well as the role of ethnicity in drug potency and efficacy. Results & Conclusion: For many drugs, the variability in drug response appears to correlate with self-reported race and estimates of genetic ancestry. Additionally, multivariate genome-wide association analyses offered interesting hypotheses governing these differential responses. PMID:26314407

Multivariate generalized multifactor dimensionality reduction to detect gene-gene interactions

PubMed Central

2013-01-01

Background Recently, one of the greatest challenges in genome-wide association studies is to detect gene-gene and/or gene-environment interactions for common complex human diseases. Ritchie et al. (2001) proposed multifactor dimensionality reduction (MDR) method for interaction analysis. MDR is a combinatorial approach to reduce multi-locus genotypes into high-risk and low-risk groups. Although MDR has been widely used for case-control studies with binary phenotypes, several extensions have been proposed. One of these methods, a generalized MDR (GMDR) proposed by Lou et al. (2007), allows adjusting for covariates and applying to both dichotomous and continuous phenotypes. GMDR uses the residual score of a generalized linear model of phenotypes to assign either high-risk or low-risk group, while MDR uses the ratio of cases to controls. Methods In this study, we propose multivariate GMDR, an extension of GMDR for multivariate phenotypes. Jointly analysing correlated multivariate phenotypes may have more power to detect susceptible genes and gene-gene interactions. We construct generalized estimating equations (GEE) with multivariate phenotypes to extend generalized linear models. Using the score vectors from GEE we discriminate high-risk from low-risk groups. We applied the multivariate GMDR method to the blood pressure data of the 7,546 subjects from the Korean Association Resource study: systolic blood pressure (SBP) and diastolic blood pressure (DBP). We compare the results of multivariate GMDR for SBP and DBP to the results from separate univariate GMDR for SBP and DBP, respectively. We also applied the multivariate GMDR method to the repeatedly measured hypertension status from 5,466 subjects and compared its result with those of univariate GMDR at each time point. Results Results from the univariate GMDR and multivariate GMDR in two-locus model with both blood pressures and hypertension phenotypes indicate best combinations of SNPs whose interaction has significant association with risk for high blood pressures or hypertension. Although the test balanced accuracy (BA) of multivariate analysis was not always greater than that of univariate analysis, the multivariate BAs were more stable with smaller standard deviations. Conclusions In this study, we have developed multivariate GMDR method using GEE approach. It is useful to use multivariate GMDR with correlated multiple phenotypes of interests. PMID:24565370

Comparison of plant cover of river valley fragments by using GIS tools and multivariate analysis

NASA Astrophysics Data System (ADS)

Waldon-Rudzionek, Barbara

2017-11-01

Selected landscape registers and results of ecological analyses of flora used in studies of transformations of anthropogenic plant cover and river valley landscapes were presented. The results were shown pursuant to a comparison of fragments of two adjacent valleys in north-western Poland.

ANALYSIS OF LOTIC MACROINVERTEBRATE ASSEMBLAGES IN CALIFORNIA'S CENTRAL VALLEY

EPA Science Inventory

Using multivariate and cluster analyses, we examined the relaitonships between chemical and physical characteristics and macroinvertebrate assemblages at sites sampled by R-EMAP in California's Central Valley. By contrasting results where community structure was summarized as met...

PHI and PCA3 improve the prognostic performance of PRIAS and Epstein criteria in predicting insignificant prostate cancer in men eligible for active surveillance.

PubMed

Cantiello, Francesco; Russo, Giorgio Ivan; Cicione, Antonio; Ferro, Matteo; Cimino, Sebastiano; Favilla, Vincenzo; Perdonà, Sisto; De Cobelli, Ottavio; Magno, Carlo; Morgia, Giuseppe; Damiano, Rocco

2016-04-01

To assess the performance of prostate health index (PHI) and prostate cancer antigen 3 (PCA3) when added to the PRIAS or Epstein criteria in predicting the presence of pathologically insignificant prostate cancer (IPCa) in patients who underwent radical prostatectomy (RP) but eligible for active surveillance (AS). An observational retrospective study was performed in 188 PCa patients treated with laparoscopic or robot-assisted RP but eligible for AS according to Epstein or PRIAS criteria. Blood and urinary specimens were collected before initial prostate biopsy for PHI and PCA3 measurements. Multivariate logistic regression analyses and decision curve analysis were carried out to identify predictors of IPCa using the updated ERSPC definition. At the multivariate analyses, the inclusion of both PCA3 and PHI significantly increased the accuracy of the Epstein multivariate model in predicting IPCa with an increase of 17 % (AUC = 0.77) and of 32 % (AUC = 0.92), respectively. The inclusion of both PCA3 and PHI also increased the predictive accuracy of the PRIAS multivariate model with an increase of 29 % (AUC = 0.87) and of 39 % (AUC = 0.97), respectively. DCA revealed that the multivariable models with the addition of PHI or PCA3 showed a greater net benefit and performed better than the reference models. In a direct comparison, PHI outperformed PCA3 performance resulting in higher net benefit. In a same cohort of patients eligible for AS, the addition of PHI and PCA3 to Epstein or PRIAS models improved their prognostic performance. PHI resulted in greater net benefit in predicting IPCa compared to PCA3.

Computational neuroanatomy using brain deformations: From brain parcellation to multivariate pattern analysis and machine learning.

PubMed

Davatzikos, Christos

2016-10-01

The past 20 years have seen a mushrooming growth of the field of computational neuroanatomy. Much of this work has been enabled by the development and refinement of powerful, high-dimensional image warping methods, which have enabled detailed brain parcellation, voxel-based morphometric analyses, and multivariate pattern analyses using machine learning approaches. The evolution of these 3 types of analyses over the years has overcome many challenges. We present the evolution of our work in these 3 directions, which largely follows the evolution of this field. We discuss the progression from single-atlas, single-registration brain parcellation work to current ensemble-based parcellation; from relatively basic mass-univariate t-tests to optimized regional pattern analyses combining deformations and residuals; and from basic application of support vector machines to generative-discriminative formulations of multivariate pattern analyses, and to methods dealing with heterogeneity of neuroanatomical patterns. We conclude with discussion of some of the future directions and challenges. Copyright © 2016. Published by Elsevier B.V.

Computational neuroanatomy using brain deformations: From brain parcellation to multivariate pattern analysis and machine learning

PubMed Central

Davatzikos, Christos

2017-01-01

The past 20 years have seen a mushrooming growth of the field of computational neuroanatomy. Much of this work has been enabled by the development and refinement of powerful, high-dimensional image warping methods, which have enabled detailed brain parcellation, voxel-based morphometric analyses, and multivariate pattern analyses using machine learning approaches. The evolution of these 3 types of analyses over the years has overcome many challenges. We present the evolution of our work in these 3 directions, which largely follows the evolution of this field. We discuss the progression from single-atlas, single-registration brain parcellation work to current ensemble-based parcellation; from relatively basic mass-univariate t-tests to optimized regional pattern analyses combining deformations and residuals; and from basic application of support vector machines to generative-discriminative formulations of multivariate pattern analyses, and to methods dealing with heterogeneity of neuroanatomical patterns. We conclude with discussion of some of the future directions and challenges. PMID:27514582

A revision of chiggers of the minuta species-group (Acari: Trombiculidae: Neotrombicula Hirst, 1925) using multivariate morphometrics.

PubMed

Stekolnikov, Alexandr A; Klimov, Pavel B

2010-09-01

We revise chiggers belonging to the minuta-species group (genus Neotrombicula Hirst, 1925) from the Palaearctic using size-free multivariate morphometrics. This approach allowed us to resolve several diagnostic problems. We show that the widely distributed Neotrombicula scrupulosa Kudryashova, 1993 forms three spatially and ecologically isolated groups different from each other in size or shape (morphometric property) only: specimens from the Caucasus are distinct from those from Asia in shape, whereas the Asian specimens from plains and mountains are different from each other in size. We developed a multivariate classification model to separate three closely related species: N. scrupulosa, N. lubrica Kudryashova, 1993 and N. minuta Schluger, 1966. This model is based on five shape variables selected from an initial 17 variables by a best subset analysis using a custom size-correction subroutine. The variable selection procedure slightly improved the predictive power of the model, suggesting that it not only removed redundancy but also reduced 'noise' in the dataset. The overall classification accuracy of this model is 96.2, 96.2 and 95.5%, as estimated by internal validation, external validation and jackknife statistics, respectively. Our analyses resulted in one new synonymy: N. dimidiata Stekolnikov, 1995 is considered to be a synonym of N. lubrica. Both N. scrupulosa and N. lubrica are recorded from new localities. A key to species of the minuta-group incorporating results from our multivariate analyses is presented.

Individual, Psychosocial, and Social Correlates of Unprotected Anal Intercourse in a New Generation of Young Men Who Have Sex With Men in New York City

PubMed Central

Kapadia, Farzana; Siconolfi, Daniel E.; Moeller, Robert W.; Figueroa, Rafael Perez; Barton, Staci C.; Blachman-Forshay, Jaclyn

2013-01-01

Objectives. We examined associations of individual, psychosocial, and social factors with unprotected anal intercourse (UAI) among young men who have sex with men in New York City. Methods. Using baseline assessment data from 592 young men who have sex with men participating in an ongoing prospective cohort study, we conducted multivariable logistic regression analyses to examine the associations between covariates and likelihood of recently engaging in UAI with same-sex partners. Results. Nineteen percent reported recent UAI with a same-sex partner. In multivariable models, being in a current relationship with another man (adjusted odds ratio [AOR] = 4.87), an arrest history (AOR = 2.01), greater residential instability (AOR = 1.75), and unstable housing or homelessness (AOR = 3.10) was associated with recent UAI. Although high levels of gay community affinity and low internalized homophobia were associated with engaging in UAI in bivariate analyses, these associations did not persist in multivariable analyses. Conclusions. Associations of psychosocial and socially produced conditions with UAI among a new generation of young men who have sex with men warrant that HIV prevention programs and policies address structural factors that predispose sexual risk behaviors. PMID:23488487

Assessing the effects of habitat patches ensuring propagule supply and different costs inclusion in marine spatial planning through multivariate analyses.

PubMed

Appolloni, L; Sandulli, R; Vetrano, G; Russo, G F

2018-05-15

Marine Protected Areas are considered key tools for conservation of coastal ecosystems. However, many reserves are characterized by several problems mainly related to inadequate zonings that often do not protect high biodiversity and propagule supply areas precluding, at the same time, economic important zones for local interests. The Gulf of Naples is here employed as a study area to assess the effects of inclusion of different conservation features and costs in reserve design process. In particular eight scenarios are developed using graph theory to identify propagule source patches and fishing and exploitation activities as costs-in-use for local population. Scenarios elaborated by MARXAN, software commonly used for marine conservation planning, are compared using multivariate analyses (MDS, PERMANOVA and PERMDISP) in order to assess input data having greatest effects on protected areas selection. MARXAN is heuristic software able to give a number of different correct results, all of them near to the best solution. Its outputs show that the most important areas to be protected, in order to ensure long-term habitat life and adequate propagule supply, are mainly located around the Gulf islands. In addition through statistical analyses it allowed us to prove that different choices on conservation features lead to statistically different scenarios. The presence of propagule supply patches forces MARXAN to select almost the same areas to protect decreasingly different MARXAN results and, thus, choices for reserves area selection. The multivariate analyses applied here to marine spatial planning proved to be very helpful allowing to identify i) how different scenario input data affect MARXAN and ii) what features have to be taken into account in study areas characterized by peculiar biological and economic interests. Copyright © 2018 Elsevier Ltd. All rights reserved.

Empirical study of the dependence of the results of multivariable flexible survival analyses on model selection strategy.

PubMed

Binquet, C; Abrahamowicz, M; Mahboubi, A; Jooste, V; Faivre, J; Bonithon-Kopp, C; Quantin, C

2008-12-30

Flexible survival models, which avoid assumptions about hazards proportionality (PH) or linearity of continuous covariates effects, bring the issues of model selection to a new level of complexity. Each 'candidate covariate' requires inter-dependent decisions regarding (i) its inclusion in the model, and representation of its effects on the log hazard as (ii) either constant over time or time-dependent (TD) and, for continuous covariates, (iii) either loglinear or non-loglinear (NL). Moreover, 'optimal' decisions for one covariate depend on the decisions regarding others. Thus, some efficient model-building strategy is necessary.We carried out an empirical study of the impact of the model selection strategy on the estimates obtained in flexible multivariable survival analyses of prognostic factors for mortality in 273 gastric cancer patients. We used 10 different strategies to select alternative multivariable parametric as well as spline-based models, allowing flexible modeling of non-parametric (TD and/or NL) effects. We employed 5-fold cross-validation to compare the predictive ability of alternative models.All flexible models indicated significant non-linearity and changes over time in the effect of age at diagnosis. Conventional 'parametric' models suggested the lack of period effect, whereas more flexible strategies indicated a significant NL effect. Cross-validation confirmed that flexible models predicted better mortality. The resulting differences in the 'final model' selected by various strategies had also impact on the risk prediction for individual subjects.Overall, our analyses underline (a) the importance of accounting for significant non-parametric effects of covariates and (b) the need for developing accurate model selection strategies for flexible survival analyses. Copyright 2008 John Wiley & Sons, Ltd.

Multi-country health surveys: are the analyses misleading?

PubMed

Masood, Mohd; Reidpath, Daniel D

2014-05-01

The aim of this paper was to review the types of approaches currently utilized in the analysis of multi-country survey data, specifically focusing on design and modeling issues with a focus on analyses of significant multi-country surveys published in 2010. A systematic search strategy was used to identify the 10 multi-country surveys and the articles published from them in 2010. The surveys were selected to reflect diverse topics and foci; and provide an insight into analytic approaches across research themes. The search identified 159 articles appropriate for full text review and data extraction. The analyses adopted in the multi-country surveys can be broadly classified as: univariate/bivariate analyses, and multivariate/multivariable analyses. Multivariate/multivariable analyses may be further divided into design- and model-based analyses. Of the 159 articles reviewed, 129 articles used model-based analysis, 30 articles used design-based analyses. Similar patterns could be seen in all the individual surveys. While there is general agreement among survey statisticians that complex surveys are most appropriately analyzed using design-based analyses, most researchers continued to use the more common model-based approaches. Recent developments in design-based multi-level analysis may be one approach to include all the survey design characteristics. This is a relatively new area, however, and there remains statistical, as well as applied analytic research required. An important limitation of this study relates to the selection of the surveys used and the choice of year for the analysis, i.e., year 2010 only. There is, however, no strong reason to believe that analytic strategies have changed radically in the past few years, and 2010 provides a credible snapshot of current practice.

Toward high value sensing: monolayer-protected metal nanoparticles in multivariable gas and vapor sensors.

PubMed

Potyrailo, Radislav A

2017-08-29

For detection of gases and vapors in complex backgrounds, "classic" analytical instruments are an unavoidable alternative to existing sensors. Recently a new generation of sensors, known as multivariable sensors, emerged with a fundamentally different perspective for sensing to eliminate limitations of existing sensors. In multivariable sensors, a sensing material is designed to have diverse responses to different gases and vapors and is coupled to a multivariable transducer that provides independent outputs to recognize these diverse responses. Data analytics tools provide rejection of interferences and multi-analyte quantitation. This review critically analyses advances of multivariable sensors based on ligand-functionalized metal nanoparticles also known as monolayer-protected nanoparticles (MPNs). These MPN sensing materials distinctively stand out from other sensing materials for multivariable sensors due to their diversity of gas- and vapor-response mechanisms as provided by organic and biological ligands, applicability of these sensing materials for broad classes of gas-phase compounds such as condensable vapors and non-condensable gases, and for several principles of signal transduction in multivariable sensors that result in non-resonant and resonant electrical sensors as well as material- and structure-based photonic sensors. Such features should allow MPN multivariable sensors to be an attractive high value addition to existing analytical instrumentation.

Multivariate analysis of volatile compounds detected by headspace solid-phase microextraction/gas chromatography: A tool for sensory classification of cork stoppers.

PubMed

Prat, Chantal; Besalú, Emili; Bañeras, Lluís; Anticó, Enriqueta

2011-06-15

The volatile fraction of aqueous cork macerates of tainted and non-tainted agglomerate cork stoppers was analysed by headspace solid-phase microextraction (HS-SPME)/gas chromatography. Twenty compounds containing terpenoids, aliphatic alcohols, lignin-related compounds and others were selected and analysed in individual corks. Cork stoppers were previously classified in six different classes according to sensory descriptions including, 2,4,6-trichloroanisole taint and other frequent, non-characteristic odours found in cork. A multivariate analysis of the chromatographic data of 20 selected chemical compounds using linear discriminant analysis models helped in the differentiation of the a priori made groups. The discriminant model selected five compounds as the best combination. Selected compounds appear in the model in the following order; 2,4,6 TCA, fenchyl alcohol, 1-octen-3-ol, benzyl alcohol and benzothiazole. Unfortunately, not all six a priori differentiated sensory classes were clearly discriminated in the model, probably indicating that no measurable differences exist in the chromatographic data for some categories. The predictive analyses of a refined model in which two sensory classes were fused together resulted in a good classification. Prediction rates of control (non-tainted), TCA, musty-earthy-vegetative, vegetative and chemical descriptions were 100%, 100%, 85%, 67.3% and 100%, respectively, when the modified model was used. The multivariate analysis of chromatographic data will help in the classification of stoppers and provide a perfect complement to sensory analyses. Copyright © 2010 Elsevier Ltd. All rights reserved.

Victimization and Suicidality among Female College Students

ERIC Educational Resources Information Center

Leone, Janel M.; Carroll, James M.

2016-01-01

Objective: To investigate the predictive role of victimization in suicidality among college women. Participants: Female respondents to the American College Health Association National College Health Assessment II (N = 258). Methods: Multivariate logistic regression analyses examined the relationship between victimization and suicidality. Results:…

Retention of community college students in online courses

NASA Astrophysics Data System (ADS)

Krajewski, Sarah

The issue of attrition in online courses at higher learning institutions remains a high priority in the United States. A recent rapid growth of online courses at community colleges has been instigated by student demand, as they meet the time constraints many nontraditional community college students have as a result of the need to work and care for dependents. Failure in an online course can cause students to become frustrated with the college experience, financially burdened, or to even give up and leave college. Attrition could be avoided by proper guidance of who is best suited for online courses. This study examined factors related to retention (i.e., course completion) and success (i.e., receiving a C or better) in an online biology course at a community college in the Midwest by operationalizing student characteristics (age, race, gender), student skills (whether or not the student met the criteria to be placed in an AFP course), and external factors (Pell recipient, full/part time status, first term) from the persistence model developed by Rovai. Internal factors from this model were not included in this study. Both univariate analyses and multivariate logistic regression were used to analyze the variables. Results suggest that race and Pell recipient were both predictive of course completion on univariate analyses. However, multivariate analyses showed that age, race, academic load and first term were predictive of completion and Pell recipient was no longer predictive. The univariate results for the C or better showed that age, race, Pell recipient, academic load, and meeting AFP criteria were predictive of success. Multivariate analyses showed that only age, race, and Pell recipient were significant predictors of success. Both regression models explained very little (<15%) of the variability within the outcome variables of retention and success. Therefore, although significant predictors were identified for course completion and retention, there are still many factors that remain unaccounted for in both regression models. Further research into the operationalization of Rovai's model, including internal factors, to predict completion and success is necessary.

Sample size calculations for case-control studies

Cancer.gov

This R package can be used to calculate the required samples size for unconditional multivariate analyses of unmatched case-control studies. The sample sizes are for a scalar exposure effect, such as binary, ordinal or continuous exposures. The sample sizes can also be computed for scalar interaction effects. The analyses account for the effects of potential confounder variables that are also included in the multivariate logistic model.

Concordance of Results from Randomized and Observational Analyses within the Same Study: A Re-Analysis of the Women’s Health Initiative Limited-Access Dataset

PubMed Central

Bolland, Mark J.; Grey, Andrew; Gamble, Greg D.; Reid, Ian R.

2015-01-01

Background Observational studies (OS) and randomized controlled trials (RCTs) often report discordant results. In the Women’s Health Initiative Calcium and Vitamin D (WHI CaD) RCT, women were randomly assigned to CaD or placebo, but were permitted to use personal calcium and vitamin D supplements, creating a unique opportunity to compare results from randomized and observational analyses within the same study. Methods WHI CaD was a 7-year RCT of 1g calcium/400IU vitamin D daily in 36,282 post-menopausal women. We assessed the effects of CaD on cardiovascular events, death, cancer and fracture in a randomized design- comparing CaD with placebo in 43% of women not using personal calcium or vitamin D supplements- and in a observational design- comparing women in the placebo group (44%) using personal calcium and vitamin D supplements with non-users. Incidence was assessed using Cox proportional hazards models, and results from the two study designs deemed concordant if the absolute difference in hazard ratios was ≤0.15. We also compared results from WHI CaD to those from the WHI Observational Study(WHI OS), which used similar methodology for analyses and recruited from the same population. Results In WHI CaD, for myocardial infarction and stroke, results of unadjusted and 6/8 covariate-controlled observational analyses (age-adjusted, multivariate-adjusted, propensity-adjusted, propensity-matched) were not concordant with the randomized design results. For death, hip and total fracture, colorectal and total cancer, unadjusted and covariate-controlled observational results were concordant with randomized results. For breast cancer, unadjusted and age-adjusted observational results were concordant with randomized results, but only 1/3 other covariate-controlled observational results were concordant with randomized results. Multivariate-adjusted results from WHI OS were concordant with randomized WHI CaD results for only 4/8 endpoints. Conclusions Results of randomized analyses in WHI CaD were concordant with observational analyses for 5/8 endpoints in WHI CaD and 4/8 endpoints in WHI OS. PMID:26440516

Concordance of Results from Randomized and Observational Analyses within the Same Study: A Re-Analysis of the Women's Health Initiative Limited-Access Dataset.

PubMed

Bolland, Mark J; Grey, Andrew; Gamble, Greg D; Reid, Ian R

2015-01-01

Observational studies (OS) and randomized controlled trials (RCTs) often report discordant results. In the Women's Health Initiative Calcium and Vitamin D (WHI CaD) RCT, women were randomly assigned to CaD or placebo, but were permitted to use personal calcium and vitamin D supplements, creating a unique opportunity to compare results from randomized and observational analyses within the same study. WHI CaD was a 7-year RCT of 1g calcium/400IU vitamin D daily in 36,282 post-menopausal women. We assessed the effects of CaD on cardiovascular events, death, cancer and fracture in a randomized design- comparing CaD with placebo in 43% of women not using personal calcium or vitamin D supplements- and in a observational design- comparing women in the placebo group (44%) using personal calcium and vitamin D supplements with non-users. Incidence was assessed using Cox proportional hazards models, and results from the two study designs deemed concordant if the absolute difference in hazard ratios was ≤0.15. We also compared results from WHI CaD to those from the WHI Observational Study(WHI OS), which used similar methodology for analyses and recruited from the same population. In WHI CaD, for myocardial infarction and stroke, results of unadjusted and 6/8 covariate-controlled observational analyses (age-adjusted, multivariate-adjusted, propensity-adjusted, propensity-matched) were not concordant with the randomized design results. For death, hip and total fracture, colorectal and total cancer, unadjusted and covariate-controlled observational results were concordant with randomized results. For breast cancer, unadjusted and age-adjusted observational results were concordant with randomized results, but only 1/3 other covariate-controlled observational results were concordant with randomized results. Multivariate-adjusted results from WHI OS were concordant with randomized WHI CaD results for only 4/8 endpoints. Results of randomized analyses in WHI CaD were concordant with observational analyses for 5/8 endpoints in WHI CaD and 4/8 endpoints in WHI OS.

A Shortened Version of the Suicide Cognitions Scale for Identifying Chronic Pain Patients at Risk for Suicide.

PubMed

Bryan, Craig J; Kanzler, Kathryn E; Grieser, Emily; Martinez, Annette; Allison, Sybil; McGeary, Donald

2017-03-01

Research in psychiatric outpatient and inpatient populations supports the utility of the Suicide Cognitions Scale (SCS) as an indicator of current and future risk for suicidal thoughts and behaviors. Designed to assess suicide-specific thoughts and beliefs, the SCS has yet to be evaluated among chronic pain patients, a group with elevated risk for suicide. The purpose of the present study was to develop and test a shortened version of the SCS (the SCS-S). A total of 228 chronic pain patients completed a battery of self-report surveys before or after a scheduled appointment. Three outpatient medical clinics (pain medicine, orofacial pain, and clinical health psychology). Confirmatory factor analysis, multivariate regression, and graded item response theory model analyses. Results of the CFAs suggested that a 3-factor solution was optimal. A shortened 9-item scale was identified based on the results of graded item response theory model analyses. Correlation and multivariate analyses supported the construct and incremental validity of the SCS-S. Results support the reliability and validity of the SCS-S among chronic pain patients, and suggest the scale may be a useful method for identifying high-risk patients in medical settings. © 2016 World Institute of Pain.

Exploratory analysis of TOF-SIMS data from biological surfaces

NASA Astrophysics Data System (ADS)

Vaidyanathan, Seetharaman; Fletcher, John S.; Henderson, Alex; Lockyer, Nicholas P.; Vickerman, John C.

2008-12-01

The application of multivariate analytical tools enables simplification of TOF-SIMS datasets so that useful information can be extracted from complex spectra and images, especially those that do not give readily interpretable results. There is however a challenge in understanding the outputs from such analyses. The problem is complicated when analysing images, given the additional dimensions in the dataset. Here we demonstrate how the application of simple pre-processing routines can enable the interpretation of TOF-SIMS spectra and images. For the spectral data, TOF-SIMS spectra used to discriminate bacterial isolates associated with urinary tract infection were studied. Using different criteria for picking peaks before carrying out PC-DFA enabled identification of the discriminatory information with greater certainty. For the image data, an air-dried salt stressed bacterial sample, discussed in another paper by us in this issue, was studied. Exploration of the image datasets with and without normalisation prior to multivariate analysis by PCA or MAF resulted in different regions of the image being highlighted by the techniques.

The classification of secondary colorectal liver cancer in human biopsy samples using angular dispersive x-ray diffraction and multivariate analysis

NASA Astrophysics Data System (ADS)

Theodorakou, Chrysoula; Farquharson, Michael J.

2009-08-01

The motivation behind this study is to assess whether angular dispersive x-ray diffraction (ADXRD) data, processed using multivariate analysis techniques, can be used for classifying secondary colorectal liver cancer tissue and normal surrounding liver tissue in human liver biopsy samples. The ADXRD profiles from a total of 60 samples of normal liver tissue and colorectal liver metastases were measured using a synchrotron radiation source. The data were analysed for 56 samples using nonlinear peak-fitting software. Four peaks were fitted to all of the ADXRD profiles, and the amplitude, area, amplitude and area ratios for three of the four peaks were calculated and used for the statistical and multivariate analysis. The statistical analysis showed that there are significant differences between all the peak-fitting parameters and ratios between the normal and the diseased tissue groups. The technique of soft independent modelling of class analogy (SIMCA) was used to classify normal liver tissue and colorectal liver metastases resulting in 67% of the normal tissue samples and 60% of the secondary colorectal liver tissue samples being classified correctly. This study has shown that the ADXRD data of normal and secondary colorectal liver cancer are statistically different and x-ray diffraction data analysed using multivariate analysis have the potential to be used as a method of tissue classification.

Angiotensin-converting Enzyme Inhibitor and Statin Medication Use and Incident Mobility Limitation in Community Older Adults. The Health, Aging and Body Composition Study

PubMed Central

Gray, Shelly L.; Boudreau, Robert M.; Newman, Anne B.; Studenski, Stephanie A.; Shorr, Ronald I; Bauer, Douglas C.; Simonsick, Eleanor M.; Hanlon, Joseph T

2012-01-01

Objective Angiotensin-converting enzyme (ACE) inhibitors and statin medications have been proposed as potential agents to prevent or delay physical disability; yet limited research has evaluated whether such use in older community dwelling adults is associated with a lower risk of incident mobility limitation. Design Longitudinal cohort study Setting Health, Aging and Body Composition (Health ABC) Participants 3055 participants who were well functioning at baseline (e.g., no mobility limitations). Measurements Summated standardized daily doses (low, medium and high) and duration of ACE inhibitor and statin use was computed. Mobility limitation (two consecutive self-reports of having any difficulty walking 1/4 mile or climbing 10 steps without resting) was assessed every 6 months after baseline. Multivariable Cox proportional hazard analyses were conducted adjusting for demographics, health status, and health behaviors. Results At baseline, ACE inhibitors and statins were used by 15.2% and 12.9%, respectively and both increased to over 25% by year 6. Over 6.5 years of follow-up, 49.8% had developed mobility limitation. In separate multivariable models, neither ACE inhibitor (multivariate hazard ratio [HR] 0.95; 95% confidence interval [CI] 0.82–1.09) nor statin use (multivariate HR 1.02; 95% CI 0.87–1.17) was associated with a lower risk for mobility limitation. Similar findings were seen in analyses examining dose- and duration-response relationships and sensitivity analyses restricted to those with hypertension. Conclusions These findings indicate that ACE inhibitors and statins widely prescribed to treat hypertension and hypercholesterolemia, respectively do not lower risk of mobility limitation, an important life quality indicator. PMID:22092102

Identification of Reliable Components in Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS): a Data-Driven Approach across Metabolic Processes.

PubMed

Motegi, Hiromi; Tsuboi, Yuuri; Saga, Ayako; Kagami, Tomoko; Inoue, Maki; Toki, Hideaki; Minowa, Osamu; Noda, Tetsuo; Kikuchi, Jun

2015-11-04

There is an increasing need to use multivariate statistical methods for understanding biological functions, identifying the mechanisms of diseases, and exploring biomarkers. In addition to classical analyses such as hierarchical cluster analysis, principal component analysis, and partial least squares discriminant analysis, various multivariate strategies, including independent component analysis, non-negative matrix factorization, and multivariate curve resolution, have recently been proposed. However, determining the number of components is problematic. Despite the proposal of several different methods, no satisfactory approach has yet been reported. To resolve this problem, we implemented a new idea: classifying a component as "reliable" or "unreliable" based on the reproducibility of its appearance, regardless of the number of components in the calculation. Using the clustering method for classification, we applied this idea to multivariate curve resolution-alternating least squares (MCR-ALS). Comparisons between conventional and modified methods applied to proton nuclear magnetic resonance ((1)H-NMR) spectral datasets derived from known standard mixtures and biological mixtures (urine and feces of mice) revealed that more plausible results are obtained by the modified method. In particular, clusters containing little information were detected with reliability. This strategy, named "cluster-aided MCR-ALS," will facilitate the attainment of more reliable results in the metabolomics datasets.

Multicollinearity in spatial genetics: separating the wheat from the chaff using commonality analyses.

PubMed

Prunier, J G; Colyn, M; Legendre, X; Nimon, K F; Flamand, M C

2015-01-01

Direct gradient analyses in spatial genetics provide unique opportunities to describe the inherent complexity of genetic variation in wildlife species and are the object of many methodological developments. However, multicollinearity among explanatory variables is a systemic issue in multivariate regression analyses and is likely to cause serious difficulties in properly interpreting results of direct gradient analyses, with the risk of erroneous conclusions, misdirected research and inefficient or counterproductive conservation measures. Using simulated data sets along with linear and logistic regressions on distance matrices, we illustrate how commonality analysis (CA), a detailed variance-partitioning procedure that was recently introduced in the field of ecology, can be used to deal with nonindependence among spatial predictors. By decomposing model fit indices into unique and common (or shared) variance components, CA allows identifying the location and magnitude of multicollinearity, revealing spurious correlations and thus thoroughly improving the interpretation of multivariate regressions. Despite a few inherent limitations, especially in the case of resistance model optimization, this review highlights the great potential of CA to account for complex multicollinearity patterns in spatial genetics and identifies future applications and lines of research. We strongly urge spatial geneticists to systematically investigate commonalities when performing direct gradient analyses. © 2014 John Wiley & Sons Ltd.

Men and women show similar survival outcome in stage IV breast cancer.

PubMed

Wu, San-Gang; Zhang, Wen-Wen; Liao, Xu-Lin; Sun, Jia-Yuan; Li, Feng-Yan; Su, Jing-Jun; He, Zhen-Yu

2017-08-01

To evaluate the clinicopathological features, patterns of distant metastases, and survival outcome between stage IV male breast cancer (MBC) and female breast cancer (FBC). Patients diagnosed with stage IV MBC and FBC between 2010 and 2013 were included using the Surveillance, Epidemiology, and End Results program. Univariate and multivariate Cox regression analyses were used to analyze risk factors for overall survival (OS). A total of 4997 patients were identified, including 60 MBC and 4937 FBC. Compared with FBC, patients with MBC were associated with a significantly higher rate of estrogen receptor-positive, progesterone receptor-positive, unmarried, lung metastases, and a lower frequency of liver metastases. Univariate and multivariate analyses showed no significant difference in OS between MBC and FBC. In the propensity score-matched population, there was also no difference in survival between MBC and FBC. Multivariate analysis of MBC showed that OS was longer for patients aged 50-69 years and with estrogen receptor-positive disease. There was no significant difference in survival outcome between stage IV MBC and FBC, but significant differences in clinicopathological features and patterns of metastases between the genders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Linking Contextual Affordances: Examining Racial-Ethnic Socialization and Parental Career Support among African American College Students

ERIC Educational Resources Information Center

Blackmon, Sha'Kema M.; Thomas, Anita Jones

2014-01-01

This exploratory investigation examined the link between self-reported racial-ethnic socialization experiences and perceived parental career support among African American undergraduate and graduate students. The results of two separate multivariate multiple regression analyses found that messages about coping with racism positively predicted…

Corporal Punishment and Student Outcomes in Rural Schools

ERIC Educational Resources Information Center

Han, Seunghee

2014-01-01

This study examined the effects of corporal punishment on student outcomes in rural schools by analyzing 1,067 samples from the School Survey on Crime and Safety 2007-2008. Results of descriptive statistics and multivariate regression analyses indicated that schools with corporal punishment may decrease students' violent behaviors and…

The Impact of Bullying and Victimization on Students' Relationships

ERIC Educational Resources Information Center

Demanet, Jannick; Van Houtte, Mieke

2012-01-01

Grschool, in Flemish secondary schools. Methods: We use data from the Flemish Educational Assessment (FlEA), consisting of 11,872 students in 85 schools. Multivariate analyses of variance (ANOVA) were performed. Results: Non-involved students felt most attached to peers, parents, teachers, and school. Bullies matched the level of parental…

Relationship between Job Burnout and Personal Wellness in Mental Health Professionals

ERIC Educational Resources Information Center

Puig, Ana; Baggs, Adrienne; Mixon, Kacy; Park, Yang Min; Kim, Bo Young; Lee, Sang Min

2012-01-01

This study aimed to determine the nature of the relationship between job burnout and personal wellness among mental health professionals. The authors performed intercorrelations and multivariate multiple regression analyses to identify the relationship between subscales of job burnout and personal wellness. Results showed that all subscales of job…

A multivariate twin study of early literacy in Japanese Kana

PubMed Central

Fujisawa, Keiko K.; Wadsworth, Sally J.; Kakihana, Shinichiro; Olson, Richard K.; DeFries, John C.; Byrne, Brian; Ando, Juko

2013-01-01

This first Japanese twin study of early literacy development investigated the extent to which genetic and environmental factors influence individual differences in prereading skills in 238 pairs of twins at 42 months of age. Twin pairs were individually tested on measures of phonological awareness, kana letter name/sound knowledge, receptive vocabulary, visual perception, nonword repetition, and digit span. Results obtained from univariate behavioral-genetic analyses yielded little evidence for genetic influences, but substantial shared-environmental influences, for all measures. Phenotypic confirmatory factor analysis suggested three correlated factors: phonological awareness, letter name/sound knowledge, and general prereading skills. Multivariate behavioral genetic analyses confirmed relatively small genetic and substantial shared environmental influences on the factors. The correlations among the three factors were mostly attributable to shared environment. Thus, shared environmental influences play an important role in the early reading development of Japanese children. PMID:23997545

Multivariable regression analysis of list experiment data on abortion: results from a large, randomly-selected population based study in Liberia.

PubMed

Moseson, Heidi; Gerdts, Caitlin; Dehlendorf, Christine; Hiatt, Robert A; Vittinghoff, Eric

2017-12-21

The list experiment is a promising measurement tool for eliciting truthful responses to stigmatized or sensitive health behaviors. However, investigators may be hesitant to adopt the method due to previously untestable assumptions and the perceived inability to conduct multivariable analysis. With a recently developed statistical test that can detect the presence of a design effect - the absence of which is a central assumption of the list experiment method - we sought to test the validity of a list experiment conducted on self-reported abortion in Liberia. We also aim to introduce recently developed multivariable regression estimators for the analysis of list experiment data, to explore relationships between respondent characteristics and having had an abortion - an important component of understanding the experiences of women who have abortions. To test the null hypothesis of no design effect in the Liberian list experiment data, we calculated the percentage of each respondent "type," characterized by response to the control items, and compared these percentages across treatment and control groups with a Bonferroni-adjusted alpha criterion. We then implemented two least squares and two maximum likelihood models (four total), each representing different bias-variance trade-offs, to estimate the association between respondent characteristics and abortion. We find no clear evidence of a design effect in list experiment data from Liberia (p = 0.18), affirming the first key assumption of the method. Multivariable analyses suggest a negative association between education and history of abortion. The retrospective nature of measuring lifetime experience of abortion, however, complicates interpretation of results, as the timing and safety of a respondent's abortion may have influenced her ability to pursue an education. Our work demonstrates that multivariable analyses, as well as statistical testing of a key design assumption, are possible with list experiment data, although with important limitations when considering lifetime measures. We outline how to implement this methodology with list experiment data in future research.

MULTIVARIATE ANALYSES (CONONICAL CORRELATION AND PARTIAL LEAST SQUARE, PLS) TO MODEL AND ASSESS THE ASSOCIATION OF LANDSCAPE METRICS TO SURFACE WATER CHEMICAL AND BIOLOGICAL PROPERTIES USING SAVANNAH RIVER BASIN DATA.

EPA Science Inventory

Many multivariate methods are used in describing and predicting relation; each has its unique usage of categorical and non-categorical data. In multivariate analysis of variance (MANOVA), many response variables (y's) are related to many independent variables that are categorical...

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.

The Risk of Achilles or Biceps Tendon Rupture in New Statin Users: A Propensity Score-Matched Sequential Cohort Study.

PubMed

Spoendlin, Julia; Layton, J Bradley; Mundkur, Mallika; Meier, Christian; Jick, Susan S; Meier, Christoph R

2016-12-01

Case reports and pharmacovigilance data reported cases of tendon ruptures in statin users, but evidence from observational studies is scarce and inconclusive. We aimed to assess the association between new statin use and tendon rupture. We performed a propensity score (PS)-matched sequential cohort study, using data from the Clinical Practice Research Datalink. Patients aged ≥45 years with at least one new statin prescription between 1995 and 2014 were PS-matched within 2-year entry blocks to patients without a statin prescription during the block. We followed patients until they had a recorded Achilles or biceps tendon rupture, completed 5 years of follow-up, or were censored for change in exposure status or another censoring criterion. We calculated hazard ratios (HRs) with 95 % confidence intervals (CIs), applying Cox proportional hazard analyses in the overall cohort (crude and multivariable) and in the PS-matched cohort. We performed subgroup analyses by sex, age, treatment duration, and statin dose. We observed a crude HR of 1.32 (95 % CI 1.21-1.44) in the overall cohort, which attenuated after multivariable adjustment (HR 1.02, 95 % CI 0.92-1.12) and after PS-matching (HR 0.95, 95 % CI 0.84-1.08). Crude HRs were higher in women than in men, but remained around null in both sexes after multivariable adjustment and PS-matching. Subgroup analyses by age, treatment duration, and statin dose revealed null results across all subgroups. The results of this cohort study suggest that statin use does not increase the risk of tendon rupture, irrespective of gender, age, statin dose, or treatment duration.

BRAF and RAS mutations as prognostic factors in metastatic colorectal cancer patients undergoing liver resection

PubMed Central

Schirripa, M; Bergamo, F; Cremolini, C; Casagrande, M; Lonardi, S; Aprile, G; Yang, D; Marmorino, F; Pasquini, G; Sensi, E; Lupi, C; De Maglio, G; Borrelli, N; Pizzolitto, S; Fasola, G; Bertorelle, R; Rugge, M; Fontanini, G; Zagonel, V; Loupakis, F; Falcone, A

2015-01-01

Background: Despite major advances in the management of metastatic colorectal cancer (mCRC) with liver-only involvement, relapse rates are high and reliable prognostic markers are needed. Methods: To assess the prognostic impact of BRAF and RAS mutations in a large series of liver-resected patients, medical records of 3024 mCRC patients were reviewed. Eligible cases undergoing potentially curative liver resection were selected. BRAF and RAS mutational status was tested on primary and/or metastases by means of pyrosequencing and mass spectrometry genotyping assay. Primary endpoint was relapse-free survival (RFS). Results: In the final study population (N=309) BRAF mutant, RAS mutant and all wild-type (wt) patients were 12(4%), 160(52%) and 137(44%), respectively. Median RFS was 5.7, 11.0 and 14.4 months respectively and differed significantly (Log-rank, P=0.043). At multivariate analyses, BRAF mutant had a higher risk of relapse in comparison to all wt (multivariate hazard ratio (HR)=2.31; 95% CI, 1.09–4.87; P=0.029) and to RAS mutant (multivariate HR=2.06; 95% CI, 1.02–4.14; P=0.044). Similar results were obtained in terms of overall survival. Compared with all wt patients, RAS mutant showed a higher risk of death (HR=1.47; 95% CI, 1.05–2.07; P=0.025), but such effect was lost at multivariate analyses. Conclusions: BRAF mutation is associated with an extremely poor median RFS after liver resection and with higher probability of relapse and death. Knowledge of BRAF mutational status may optimise clinical decision making in mCRC patients potentially candidate to hepatic surgery. RAS status as useful marker in this setting might require further studies. PMID:25942399

Comparison of connectivity analyses for resting state EEG data

NASA Astrophysics Data System (ADS)

Olejarczyk, Elzbieta; Marzetti, Laura; Pizzella, Vittorio; Zappasodi, Filippo

2017-06-01

Objective. In the present work, a nonlinear measure (transfer entropy, TE) was used in a multivariate approach for the analysis of effective connectivity in high density resting state EEG data in eyes open and eyes closed. Advantages of the multivariate approach in comparison to the bivariate one were tested. Moreover, the multivariate TE was compared to an effective linear measure, i.e. directed transfer function (DTF). Finally, the existence of a relationship between the information transfer and the level of brain synchronization as measured by phase synchronization value (PLV) was investigated. Approach. The comparison between the connectivity measures, i.e. bivariate versus multivariate TE, TE versus DTF, TE versus PLV, was performed by means of statistical analysis of indexes based on graph theory. Main results. The multivariate approach is less sensitive to false indirect connections with respect to the bivariate estimates. The multivariate TE differentiated better between eyes closed and eyes open conditions compared to DTF. Moreover, the multivariate TE evidenced non-linear phenomena in information transfer, which are not evidenced by the use of DTF. We also showed that the target of information flow, in particular the frontal region, is an area of greater brain synchronization. Significance. Comparison of different connectivity analysis methods pointed to the advantages of nonlinear methods, and indicated a relationship existing between the flow of information and the level of synchronization of the brain.

Causal diagrams and multivariate analysis II: precision work.

PubMed

Jupiter, Daniel C

2014-01-01

In this Investigators' Corner, I continue my discussion of when and why we researchers should include variables in multivariate regression. My examination focuses on studies comparing treatment groups and situations for which we can either exclude variables from multivariate analyses or include them for reasons of precision. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Multivariate two-part statistics for analysis of correlated mass spectrometry data from multiple biological specimens.

PubMed

Taylor, Sandra L; Ruhaak, L Renee; Weiss, Robert H; Kelly, Karen; Kim, Kyoungmi

2017-01-01

High through-put mass spectrometry (MS) is now being used to profile small molecular compounds across multiple biological sample types from the same subjects with the goal of leveraging information across biospecimens. Multivariate statistical methods that combine information from all biospecimens could be more powerful than the usual univariate analyses. However, missing values are common in MS data and imputation can impact between-biospecimen correlation and multivariate analysis results. We propose two multivariate two-part statistics that accommodate missing values and combine data from all biospecimens to identify differentially regulated compounds. Statistical significance is determined using a multivariate permutation null distribution. Relative to univariate tests, the multivariate procedures detected more significant compounds in three biological datasets. In a simulation study, we showed that multi-biospecimen testing procedures were more powerful than single-biospecimen methods when compounds are differentially regulated in multiple biospecimens but univariate methods can be more powerful if compounds are differentially regulated in only one biospecimen. We provide R functions to implement and illustrate our method as supplementary information CONTACT: sltaylor@ucdavis.eduSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

CpG island methylator phenotype identifies high risk patients among microsatellite stable BRAF mutated colorectal cancers

PubMed Central

Vedeld, Hege Marie; Merok, Marianne; Jeanmougin, Marine; Danielsen, Stine A.; Honne, Hilde; Presthus, Gro Kummeneje; Svindland, Aud; Sjo, Ole H.; Hektoen, Merete; Eknæs, Mette; Nesbakken, Arild; Lothe, Ragnhild A.

2017-01-01

The prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer remains unsettled. We aimed to assess the prognostic value of this phenotype analyzing a total of 1126 tumor samples obtained from two Norwegian consecutive colorectal cancer series. CIMP status was determined by analyzing the 5‐markers CAGNA1G, IGF2, NEUROG1, RUNX3 and SOCS1 by quantitative methylation specific PCR (qMSP). The effect of CIMP on time to recurrence (TTR) and overall survival (OS) were determined by uni‐ and multivariate analyses. Subgroup analyses were conducted according to MSI and BRAF mutation status, disease stage, and also age at time of diagnosis (<60, 60‐74, ≥75 years). Patients with CIMP positive tumors demonstrated significantly shorter TTR and worse OS compared to those with CIMP negative tumors (multivariate hazard ratio [95% CI] 1.86 [1.31‐2.63] and 1.89 [1.34‐2.65], respectively). In stratified analyses, CIMP tumors showed significantly worse outcome among patients with microsatellite stable (MSS, P < 0.001), and MSS BRAF mutated tumors (P < 0.001), a finding that persisted in patients with stage II, III or IV disease, and that remained significant in multivariate analysis (P < 0.01). Consistent results were found for all three age groups. To conclude, CIMP is significantly associated with inferior outcome for colorectal cancer patients, and can stratify the poor prognostic patients with MSS BRAF mutated tumors. PMID:28542846

Correlation between smoking habit and surgical outcomes on viral-associated hepatocellular carcinomas

PubMed Central

Kai, Keita; Komukai, Sho; Koga, Hiroki; Yamaji, Koutaro; Ide, Takao; Kawaguchi, Atsushi; Aishima, Shinichi; Noshiro, Hirokazu

2018-01-01

AIM To investigate the association between smoking habits and surgical outcomes in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) (B-HCC) and hepatitis C virus (HCV)-related HCC (C-HCC) and clarify the clinicopathological features associated with smoking status in B-HCC and C-HCC patients. METHODS We retrospectively examined the cases of the 341 consecutive patients with viral-associated HCC (C-HCC, n = 273; B-HCC, n = 68) who underwent curative surgery for their primary lesion. We categorized smoking status at the time of surgery into never, ex- and current smoker. We analyzed the B-HCC and C-HCC groups’ clinicopathological features and surgical outcomes, i.e., disease-free survival (DFS), overall survival (OS), and disease-specific survival (DSS). Univariate and multivariate analyses were performed using a Cox proportional hazards regression model. We also performed subset analyses in both patient groups comparing the current smokers to the other patients. RESULTS The multivariate analysis in the C-HCC group revealed that current-smoker status was significantly correlated with both OS (P = 0.0039) and DSS (P = 0.0416). In the B-HCC patients, no significant correlation was observed between current-smoker status and DFS, OS, or DSS in the univariate or multivariate analyses. The subset analyses comparing the current smokers to the other patients in both the C-HCC and B-HCC groups revealed that the current smokers developed HCC at significantly younger ages than the other patients irrespective of viral infection status. CONCLUSION A smoking habit is significantly correlated with the overall and disease-specific survivals of patients with C-HCC. In contrast, the B-HCC patients showed a weak association between smoking status and surgical outcomes. PMID:29358882

Fetal Growth and Childhood Acute Lymphoblastic Leukemia: Findings from the Childhood Leukemia International Consortium (CLIC)

PubMed Central

Milne, Elizabeth; Greenop, Kathryn R.; Metayer, Catherine; Schüz, Joachim; Petridou, Eleni; Pombo-de-Oliveira, Maria S.; Infante-Rivard, Claire; Roman, Eve; Dockerty, John D.; Spector, Logan G.; Koifman, Sérgio; Orsi, Laurent; Rudant, Jérémie; Dessypris, Nick; Simpson, Jill; Lightfoot, Tracy; Kaatsch, Peter; Baka, Margarita; Faro, Alessandra; Armstrong, Bruce K.; Clavel, Jacqueline; Buffler, Patricia A.

2013-01-01

Positive associations have been reported between measures of accelerated fetal growth and risk of childhood acute lymphoblastic leukemia (ALL). We investigated this association by pooling individual-level data from 12 case-control studies participating in the Childhood Leukemia International Consortium. Two measures of fetal growth – weight-for-gestational-age and proportion of optimal birth weight (POBW) – were analysed. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression, and combined in fixed effects meta-analyses. Pooled analyses of all data were also undertaken using multivariable logistic regression. Subgroup analyses were undertaken when possible. Data on weight for gestational age were available for 7,348 cases and 12,489 controls from all 12 studies and POBW data were available for 1,680 cases and 3,139 controls from three studies. The summary ORs from the meta-analyses were 1.24 (95% CI 1.13, 1.36) for children who were large for gestational age relative to appropriate for gestational age, and 1.16 (95% CI: 1.09, 1.24) for a one standard deviation increase in POBW. The pooled analyses produced similar results. The summary and pooled ORs for small-for-gestational-age children were 0.83 (95% CI: 0.75, 0.92) and 0.86 (95% CI 0.77, 0.95) respectively. Results were consistent across subgroups defined by sex, ethnicity and immunophenotype, and when the analysis was restricted to children who did not have high birth weight. The evidence that accelerated fetal growth is associated with a modest increased risk of childhood ALL is strong and consistent with known biological mechanisms involving insulin like growth factors. PMID:23754574

Influence of Gender on Parental Socialization of Children's Sadness Regulation

ERIC Educational Resources Information Center

Cassano, Michael; Perry-Parrish, Carisa; Zeman, Janice

2007-01-01

Mothers' (N = 60) and fathers' (N = 53) perceptions of and desire for change in their 6- to 11-year-old daughters' (N = 59) and sons' (N = 54) sadness regulation behaviors (i.e., inhibition, dysregulation, coping) were examined in addition to parental responses to children's hypothetical sadness displays. Results of multivariate analyses of…

Employment, Work Conditions, and the Home Environment in Single-Mother Families

ERIC Educational Resources Information Center

Lleras, Christy

2008-01-01

This study investigates the impact of employment status and work conditions on the quality of the home environment provided by single mothers of preschool-age children. Multivariate analyses were conducted using data from the National Longitudinal Survey of Youth. The results indicate that employment status is not a significant predictor of the…

Religion and HPV vaccine-related awareness, knowledge, and receipt among insured women aged 18-26 in Utah

PubMed Central

2017-01-01

Introduction We investigate the associations between religious practice and human papillomavirus (HPV) vaccine-related awareness, knowledge, and receipt among young women in Utah. Methods We surveyed 326 insured women aged 18–26 by mail. Fisher's Exact Tests and multivariable logistic regression models were used to evaluate the relations between religious practice and HPV vaccine-related outcomes. Data collection occurred January-December 2013; analyses were conducted June-September 2015. Results Multivariable analyses reveal that when controlling for age, educational attainment, and marital status, participants who practiced an organized religion were significantly less likely to have heard of HPV (aOR = 0.25, p = 0.0123), to have heard of the HPV vaccine (aOR = 0.41, p = 0.0368), to know how HPV is spread (aOR = 0.45, p = 0.0074), to have received a provider recommendation for the HPV vaccine (aOR = 0.36, p = 0.0332), and to have received at least one (aOR = 0.50, p = 0.0073) or all three (aOR = 0.47, p = 0.0026) doses of the HPV vaccine. Bivariate analyses produce parallel results. Conclusions Results indicate that religious young women in Utah are not only under-vaccinated, but are also under-informed about HPV and the HPV vaccine. These results suggest that suboptimal vaccine coverage among religious young women may present a serious health risk for the community. Strategies for educational interventions targeted to this population are discussed. PMID:28841681

The Multivariate Largest Lyapunov Exponent as an Age-Related Metric of Quiet Standing Balance

PubMed Central

Liu, Kun; Wang, Hongrui; Xiao, Jinzhuang

2015-01-01

The largest Lyapunov exponent has been researched as a metric of the balance ability during human quiet standing. However, the sensitivity and accuracy of this measurement method are not good enough for clinical use. The present research proposes a metric of the human body's standing balance ability based on the multivariate largest Lyapunov exponent which can quantify the human standing balance. The dynamic multivariate time series of ankle, knee, and hip were measured by multiple electrical goniometers. Thirty-six normal people of different ages participated in the test. With acquired data, the multivariate largest Lyapunov exponent was calculated. Finally, the results of the proposed approach were analysed and compared with the traditional method, for which the largest Lyapunov exponent and power spectral density from the centre of pressure were also calculated. The following conclusions can be obtained. The multivariate largest Lyapunov exponent has a higher degree of differentiation in differentiating balance in eyes-closed conditions. The MLLE value reflects the overall coordination between multisegment movements. Individuals of different ages can be distinguished by their MLLE values. The standing stability of human is reduced with the increment of age. PMID:26064182

Numerical analysis of the effect of the kind of activating agent and the impregnation ratio on the parameters of the microporous structure of the active carbons

NASA Astrophysics Data System (ADS)

Kwiatkowski, Mirosław

2015-09-01

The paper presents the results of the research on the application of the LBET class adsorption models with the fast multivariant identification procedure as a tool for analysing the microporous structure of the active carbons obtained by chemical activation using potassium and sodium hydroxides as an activator. The proposed technique of the fast multivariant fitting of the LBET class models to the empirical adsorption data was employed particularly to evaluate the impact of the used activator and the impregnation ratio on the obtained microporous structure of the carbonaceous adsorbents.

Network meta-analysis of multiple outcome measures accounting for borrowing of information across outcomes

PubMed Central

2014-01-01

Background Network meta-analysis (NMA) enables simultaneous comparison of multiple treatments while preserving randomisation. When summarising evidence to inform an economic evaluation, it is important that the analysis accurately reflects the dependency structure within the data, as correlations between outcomes may have implication for estimating the net benefit associated with treatment. A multivariate NMA offers a framework for evaluating multiple treatments across multiple outcome measures while accounting for the correlation structure between outcomes. Methods The standard NMA model is extended to multiple outcome settings in two stages. In the first stage, information is borrowed across outcomes as well across studies through modelling the within-study and between-study correlation structure. In the second stage, we make use of the additional assumption that intervention effects are exchangeable between outcomes to predict effect estimates for all outcomes, including effect estimates on outcomes where evidence is either sparse or the treatment had not been considered by any one of the studies included in the analysis. We apply the methods to binary outcome data from a systematic review evaluating the effectiveness of nine home safety interventions on uptake of three poisoning prevention practices (safe storage of medicines, safe storage of other household products, and possession of poison centre control telephone number) in households with children. Analyses are conducted in WinBUGS using Markov Chain Monte Carlo (MCMC) simulations. Results Univariate and the first stage multivariate models produced broadly similar point estimates of intervention effects but the uncertainty around the multivariate estimates varied depending on the prior distribution specified for the between-study covariance structure. The second stage multivariate analyses produced more precise effect estimates while enabling intervention effects to be predicted for all outcomes, including intervention effects on outcomes not directly considered by the studies included in the analysis. Conclusions Accounting for the dependency between outcomes in a multivariate meta-analysis may or may not improve the precision of effect estimates from a network meta-analysis compared to analysing each outcome separately. PMID:25047164

Publication of statistically significant research findings in prosthodontics & implant dentistry in the context of other dental specialties.

PubMed

Papageorgiou, Spyridon N; Kloukos, Dimitrios; Petridis, Haralampos; Pandis, Nikolaos

2015-10-01

To assess the hypothesis that there is excessive reporting of statistically significant studies published in prosthodontic and implantology journals, which could indicate selective publication. The last 30 issues of 9 journals in prosthodontics and implant dentistry were hand-searched for articles with statistical analyses. The percentages of significant and non-significant results were tabulated by parameter of interest. Univariable/multivariable logistic regression analyses were applied to identify possible predictors of reporting statistically significance findings. The results of this study were compared with similar studies in dentistry with random-effects meta-analyses. From the 2323 included studies 71% of them reported statistically significant results, with the significant results ranging from 47% to 86%. Multivariable modeling identified that geographical area and involvement of statistician were predictors of statistically significant results. Compared to interventional studies, the odds that in vitro and observational studies would report statistically significant results was increased by 1.20 times (OR: 2.20, 95% CI: 1.66-2.92) and 0.35 times (OR: 1.35, 95% CI: 1.05-1.73), respectively. The probability of statistically significant results from randomized controlled trials was significantly lower compared to various study designs (difference: 30%, 95% CI: 11-49%). Likewise the probability of statistically significant results in prosthodontics and implant dentistry was lower compared to other dental specialties, but this result did not reach statistical significant (P>0.05). The majority of studies identified in the fields of prosthodontics and implant dentistry presented statistically significant results. The same trend existed in publications of other specialties in dentistry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sex Hormones and Sleep in Men and Women From the General Population: A Cross-Sectional Observational Study.

PubMed

Kische, Hanna; Ewert, Ralf; Fietze, Ingo; Gross, Stefan; Wallaschofski, Henri; Völzke, Henry; Dörr, Marcus; Nauck, Matthias; Obst, Anne; Stubbe, Beate; Penzel, Thomas; Haring, Robin

2016-11-01

Associations between sex hormones and sleep habits originate mainly from small and selected patient-based samples. We examined data from a population-based sample with various sleep characteristics and the major part of sex hormones measured by mass spectrometry. We used data from 204 men and 213 women of the cross-sectional Study of Health in Pomerania-TREND. Associations of total T (TT) and free T, androstenedione (ASD), estrone, estradiol (E2), dehydroepiandrosterone-sulphate, SHBG, and E2 to TT ratio with sleep measures (including total sleep time, sleep efficiency, wake after sleep onset, apnea-hypopnea index [AHI], Insomnia Severity Index, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index) were assessed by sex-specific multivariable regression models. In men, age-adjusted associations of TT (odds ratio 0.62; 95% confidence interval (CI) 0.46-0.83), free T, and SHBG with AHI were rendered nonsignificant after multivariable adjustment. In multivariable analyses, ASD was associated with Epworth Sleepiness Scale (β-coefficient per SD increase in ASD: -0.71; 95% CI: -1.18 to -0.25). In women, multivariable analyses showed positive associations of dehydroepiandrosterone-sulphate with wake after sleep onset (β-coefficient: .16; 95% CI 0.03-0.28) and of E2 and E2 to TT ratio with Epworth Sleepiness Scale. Additionally, free T and SHBG were associated with AHI in multivariable models among premenopausal women. The present cross-sectional, population-based study observed sex-specific associations of androgens, E2, and SHBG with sleep apnea and daytime sleepiness. However, multivariable-adjusted analyses confirmed the impact of body composition and health-related lifestyle on the association between sex hormones and sleep.

Resemblance profiles as clustering decision criteria: Estimating statistical power, error, and correspondence for a hypothesis test for multivariate structure.

PubMed

Kilborn, Joshua P; Jones, David L; Peebles, Ernst B; Naar, David F

2017-04-01

Clustering data continues to be a highly active area of data analysis, and resemblance profiles are being incorporated into ecological methodologies as a hypothesis testing-based approach to clustering multivariate data. However, these new clustering techniques have not been rigorously tested to determine the performance variability based on the algorithm's assumptions or any underlying data structures. Here, we use simulation studies to estimate the statistical error rates for the hypothesis test for multivariate structure based on dissimilarity profiles (DISPROF). We concurrently tested a widely used algorithm that employs the unweighted pair group method with arithmetic mean (UPGMA) to estimate the proficiency of clustering with DISPROF as a decision criterion. We simulated unstructured multivariate data from different probability distributions with increasing numbers of objects and descriptors, and grouped data with increasing overlap, overdispersion for ecological data, and correlation among descriptors within groups. Using simulated data, we measured the resolution and correspondence of clustering solutions achieved by DISPROF with UPGMA against the reference grouping partitions used to simulate the structured test datasets. Our results highlight the dynamic interactions between dataset dimensionality, group overlap, and the properties of the descriptors within a group (i.e., overdispersion or correlation structure) that are relevant to resemblance profiles as a clustering criterion for multivariate data. These methods are particularly useful for multivariate ecological datasets that benefit from distance-based statistical analyses. We propose guidelines for using DISPROF as a clustering decision tool that will help future users avoid potential pitfalls during the application of methods and the interpretation of results.

mvMapper: statistical and geographical data exploration and visualization of multivariate analysis of population structure

USDA-ARS?s Scientific Manuscript database

Characterizing population genetic structure across geographic space is a fundamental challenge in population genetics. Multivariate statistical analyses are powerful tools for summarizing genetic variability, but geographic information and accompanying metadata is not always easily integrated into t...

Multivariate analysis of prognostic factors for idiopathic sudden sensorineural hearing loss treated with adjuvant hyperbaric oxygen therapy.

PubMed

Xie, Shaobing; Qiang, Qingfen; Mei, Lingyun; He, Chufeng; Feng, Yong; Sun, Hong; Wu, Xuewen

2018-01-01

The objective of this study is to evaluate possible prognostic factors of idiopathic sudden sensorineural hearing loss (ISSNHL) treated with adjuvant hyperbaric oxygen therapy (HBOT) using univariate and multivariate analyses. From January 2008 to October 2016, records of 178 ISSNHL patients treated with auxiliary hyperbaric oxygen therapy were reviewed to assess hearing recovery and evaluate associated prognostic factors (gender, age, localization, initial hearing threshold, presence of tinnitus, vertigo, ear fullness, hypertension, diabetes, onset of HBOT, number of HBOT, and audiogram), by using univariate and multivariate analyses. The overall recovery rate was 37.1%, including complete recovery (19.7%) and partial recovery (17.4%). According to multivariate analysis, later onset of HBOT and higher initial hearing threshold were associated with a poor prognosis in ISSNHL patients treated with HBOT. HBOT is a safe and beneficial adjuvant therapy for ISSNHL patients. 20 sessions of HBOT is possibly enough to show its therapeutic effect. Earlier HBOT onset and lower initial hearing threshold is associated with favorable hearing recovery.

An assessment on the use of bivariate, multivariate and soft computing techniques for collapse susceptibility in GIS environ

NASA Astrophysics Data System (ADS)

Yilmaz, Işik; Marschalko, Marian; Bednarik, Martin

2013-04-01

The paper presented herein compares and discusses the use of bivariate, multivariate and soft computing techniques for collapse susceptibility modelling. Conditional probability (CP), logistic regression (LR) and artificial neural networks (ANN) models representing the bivariate, multivariate and soft computing techniques were used in GIS based collapse susceptibility mapping in an area from Sivas basin (Turkey). Collapse-related factors, directly or indirectly related to the causes of collapse occurrence, such as distance from faults, slope angle and aspect, topographical elevation, distance from drainage, topographic wetness index (TWI), stream power index (SPI), Normalized Difference Vegetation Index (NDVI) by means of vegetation cover, distance from roads and settlements were used in the collapse susceptibility analyses. In the last stage of the analyses, collapse susceptibility maps were produced from the models, and they were then compared by means of their validations. However, Area Under Curve (AUC) values obtained from all three models showed that the map obtained from soft computing (ANN) model looks like more accurate than the other models, accuracies of all three models can be evaluated relatively similar. The results also showed that the conditional probability is an essential method in preparation of collapse susceptibility map and highly compatible with GIS operating features.

Using Multivariate Generalizability Theory to Assess the Effect of Content Stratification on the Reliability of a Performance Assessment

ERIC Educational Resources Information Center

Keller, Lisa A.; Clauser, Brian E.; Swanson, David B.

2010-01-01

In recent years, demand for performance assessments has continued to grow. However, performance assessments are notorious for lower reliability, and in particular, low reliability resulting from task specificity. Since reliability analyses typically treat the performance tasks as randomly sampled from an infinite universe of tasks, these estimates…

Postsecondary Student Mobility from College to University: Academic Performance of Students

ERIC Educational Resources Information Center

Gerhardt, Kris; Masakure, Oliver

2016-01-01

This paper considers the impact of transfer credits on the GPA of college-university transfer students. The data come from the academic records of students enrolled at 2 different campuses at an undergraduate university in Ontario across a 4-year period. The results from multivariate regression analyses show that the number of transfer credits is…

A multivariate analysis of genetic constraints to life history evolution in a wild population of red deer.

PubMed

Walling, Craig A; Morrissey, Michael B; Foerster, Katharina; Clutton-Brock, Tim H; Pemberton, Josephine M; Kruuk, Loeske E B

2014-12-01

Evolutionary theory predicts that genetic constraints should be widespread, but empirical support for their existence is surprisingly rare. Commonly applied univariate and bivariate approaches to detecting genetic constraints can underestimate their prevalence, with important aspects potentially tractable only within a multivariate framework. However, multivariate genetic analyses of data from natural populations are challenging because of modest sample sizes, incomplete pedigrees, and missing data. Here we present results from a study of a comprehensive set of life history traits (juvenile survival, age at first breeding, annual fecundity, and longevity) for both males and females in a wild, pedigreed, population of red deer (Cervus elaphus). We use factor analytic modeling of the genetic variance-covariance matrix ( G: ) to reduce the dimensionality of the problem and take a multivariate approach to estimating genetic constraints. We consider a range of metrics designed to assess the effect of G: on the deflection of a predicted response to selection away from the direction of fastest adaptation and on the evolvability of the traits. We found limited support for genetic constraint through genetic covariances between traits, both within sex and between sexes. We discuss these results with respect to other recent findings and to the problems of estimating these parameters for natural populations. Copyright © 2014 Walling et al.

A Multivariate Analysis of Genetic Constraints to Life History Evolution in a Wild Population of Red Deer

PubMed Central

Walling, Craig A.; Morrissey, Michael B.; Foerster, Katharina; Clutton-Brock, Tim H.; Pemberton, Josephine M.; Kruuk, Loeske E. B.

2014-01-01

Evolutionary theory predicts that genetic constraints should be widespread, but empirical support for their existence is surprisingly rare. Commonly applied univariate and bivariate approaches to detecting genetic constraints can underestimate their prevalence, with important aspects potentially tractable only within a multivariate framework. However, multivariate genetic analyses of data from natural populations are challenging because of modest sample sizes, incomplete pedigrees, and missing data. Here we present results from a study of a comprehensive set of life history traits (juvenile survival, age at first breeding, annual fecundity, and longevity) for both males and females in a wild, pedigreed, population of red deer (Cervus elaphus). We use factor analytic modeling of the genetic variance–covariance matrix (G) to reduce the dimensionality of the problem and take a multivariate approach to estimating genetic constraints. We consider a range of metrics designed to assess the effect of G on the deflection of a predicted response to selection away from the direction of fastest adaptation and on the evolvability of the traits. We found limited support for genetic constraint through genetic covariances between traits, both within sex and between sexes. We discuss these results with respect to other recent findings and to the problems of estimating these parameters for natural populations. PMID:25278555

A multivariate variational objective analysis-assimilation method. Part 2: Case study results with and without satellite data

NASA Technical Reports Server (NTRS)

Achtemeier, Gary L.; Kidder, Stanley Q.; Scott, Robert W.

1988-01-01

The variational multivariate assimilation method described in a companion paper by Achtemeier and Ochs is applied to conventional and conventional plus satellite data. Ground-based and space-based meteorological data are weighted according to the respective measurement errors and blended into a data set that is a solution of numerical forms of the two nonlinear horizontal momentum equations, the hydrostatic equation, and an integrated continuity equation for a dry atmosphere. The analyses serve first, to evaluate the accuracy of the model, and second to contrast the analyses with and without satellite data. Evaluation criteria measure the extent to which: (1) the assimilated fields satisfy the dynamical constraints, (2) the assimilated fields depart from the observations, and (3) the assimilated fields are judged to be realistic through pattern analysis. The last criterion requires that the signs, magnitudes, and patterns of the hypersensitive vertical velocity and local tendencies of the horizontal velocity components be physically consistent with respect to the larger scale weather systems.

Predictive Utility of Brief Alcohol Use Disorders Identification Test (AUDIT) for human immunodeficiency virus antiretroviral medication nonadherence.

PubMed

Broyles, Lauren Matukaitis; Gordon, Adam J; Sereika, Susan M; Ryan, Christopher M; Erlen, Judith A

2011-10-01

Alcohol use negatively affects adherence to antiretroviral therapy (ART), thus human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) care providers need accurate, efficient assessments of alcohol use. Using existing data from an efficacy trial of 2 cognitive-behavioral ART adherence interventions, the authors sought to determine if results on 2 common alcohol screening tests (Alcohol Use Disorders Identification Test--Consumption [AUDIT-C] and its binge-related question [AUDIT-3]) predict ART nonadherence. Twenty-seven percent of the sample (n = 308) were positive on the AUDIT-C and 34% were positive on the AUDIT-3. In multivariate analyses, AUDIT-C-positive status predicted ART nonadherence after controlling for race, age, conscientiousness, and self-efficacy (P = .036). Although AUDIT-3-positive status was associated with ART nonadherence in unadjusted analyses, this relationship was not maintained in the final multivariate model. The AUDIT-C shows potential as an indirect screening tool for both at-risk drinking and ART nonadherence, underscoring the relationship between alcohol and chronic disease management.

Predictive Utility of Brief AUDIT for HIV Antiretroviral Medication Nonadherence

PubMed Central

Broyles, Lauren Matukaitis; Gordon, Adam J.; Sereika, Susan M.; Ryan, Christopher M.; Erlen, Judith A.

2012-01-01

Alcohol use negatively affects adherence to antiretroviral therapy (ART), thus HIV/AIDS providers need accurate, efficient assessments of alcohol use. Using existing data from an efficacy trial of two cognitive-behavioral ART adherence interventions, we sought to determine if results on two common alcohol screening tests (Alcohol Use Disorders Identification Test—Consumption (AUDIT-C) and its binge-related question (AUDIT-3)) predict ART nonadherence. Twenty seven percent of the sample (n=308) were positive on the AUDIT-C and 34% were positive on the AUDIT-3. In multivariate analyses, AUDIT-C positive status predicted ART nonadherence after controlling for race, age, conscientiousness, and self-efficacy (p=.036). While AUDIT-3 positive status was associated with ART nonadherence in unadjusted analyses, this relationship was not maintained in the final multivariate model. The AUDIT-C shows potential as an indirect screening tool for both at-risk drinking and ART nonadherence, underscoring the relationship between alcohol and chronic disease management. PMID:22014256

The impact on social relationships of moving from congregated settings to personalized accommodation.

PubMed

McConkey, Roy; Bunting, Brendan; Keogh, Fiona; Garcia Iriarte, Edurne

2017-01-01

A natural experiment contrasted the social relationships of people with intellectual disabilities ( n = 110) before and after they moved from congregated settings to either personalized accommodation or group homes. Contrasts could also be drawn with individuals who had enduring mental health problems ( n = 46) and who experienced similar moves. Face-to-face interviews were conducted in each person's residence on two occasions approximately 24 months apart. Multivariate statistical analyses were used to determine significant effects. Greater proportions of people living in personalized settings scored higher on the five chosen indicators of social relationships than did persons living in grouped accommodation. However, multivariate statistical analyses identified that only one in five persons increased their social relationships as a result of changes in their accommodation, particularly persons with an intellectual disability and high support needs. These findings reinforce the extent of social isolation experienced by people with disabilities and mental health problems that changes in their accommodation only partially counter.

Religion and HPV vaccine-related awareness, knowledge, and receipt among insured women aged 18-26 in Utah.

PubMed

Bodson, Julia; Wilson, Andrew; Warner, Echo L; Kepka, Deanna

2017-01-01

We investigate the associations between religious practice and human papillomavirus (HPV) vaccine-related awareness, knowledge, and receipt among young women in Utah. We surveyed 326 insured women aged 18-26 by mail. Fisher's Exact Tests and multivariable logistic regression models were used to evaluate the relations between religious practice and HPV vaccine-related outcomes. Data collection occurred January-December 2013; analyses were conducted June-September 2015. Multivariable analyses reveal that when controlling for age, educational attainment, and marital status, participants who practiced an organized religion were significantly less likely to have heard of HPV (aOR = 0.25, p = 0.0123), to have heard of the HPV vaccine (aOR = 0.41, p = 0.0368), to know how HPV is spread (aOR = 0.45, p = 0.0074), to have received a provider recommendation for the HPV vaccine (aOR = 0.36, p = 0.0332), and to have received at least one (aOR = 0.50, p = 0.0073) or all three (aOR = 0.47, p = 0.0026) doses of the HPV vaccine. Bivariate analyses produce parallel results. Results indicate that religious young women in Utah are not only under-vaccinated, but are also under-informed about HPV and the HPV vaccine. These results suggest that suboptimal vaccine coverage among religious young women may present a serious health risk for the community. Strategies for educational interventions targeted to this population are discussed.

CpG island methylator phenotype identifies high risk patients among microsatellite stable BRAF mutated colorectal cancers.

PubMed

Vedeld, Hege Marie; Merok, Marianne; Jeanmougin, Marine; Danielsen, Stine A; Honne, Hilde; Presthus, Gro Kummeneje; Svindland, Aud; Sjo, Ole H; Hektoen, Merete; Eknaes, Mette; Nesbakken, Arild; Lothe, Ragnhild A; Lind, Guro E

2017-09-01

The prognostic value of CpG island methylator phenotype (CIMP) in colorectal cancer remains unsettled. We aimed to assess the prognostic value of this phenotype analyzing a total of 1126 tumor samples obtained from two Norwegian consecutive colorectal cancer series. CIMP status was determined by analyzing the 5-markers CAGNA1G, IGF2, NEUROG1, RUNX3 and SOCS1 by quantitative methylation specific PCR (qMSP). The effect of CIMP on time to recurrence (TTR) and overall survival (OS) were determined by uni- and multivariate analyses. Subgroup analyses were conducted according to MSI and BRAF mutation status, disease stage, and also age at time of diagnosis (<60, 60-74, ≥75 years). Patients with CIMP positive tumors demonstrated significantly shorter TTR and worse OS compared to those with CIMP negative tumors (multivariate hazard ratio [95% CI] 1.86 [1.31-2.63] and 1.89 [1.34-2.65], respectively). In stratified analyses, CIMP tumors showed significantly worse outcome among patients with microsatellite stable (MSS, P < 0.001), and MSS BRAF mutated tumors (P < 0.001), a finding that persisted in patients with stage II, III or IV disease, and that remained significant in multivariate analysis (P < 0.01). Consistent results were found for all three age groups. To conclude, CIMP is significantly associated with inferior outcome for colorectal cancer patients, and can stratify the poor prognostic patients with MSS BRAF mutated tumors. © 2017 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.

Hybrid approach combining chemometrics and likelihood ratio framework for reporting the evidential value of spectra.

PubMed

Martyna, Agnieszka; Zadora, Grzegorz; Neocleous, Tereza; Michalska, Aleksandra; Dean, Nema

2016-08-10

Many chemometric tools are invaluable and have proven effective in data mining and substantial dimensionality reduction of highly multivariate data. This becomes vital for interpreting various physicochemical data due to rapid development of advanced analytical techniques, delivering much information in a single measurement run. This concerns especially spectra, which are frequently used as the subject of comparative analysis in e.g. forensic sciences. In the presented study the microtraces collected from the scenarios of hit-and-run accidents were analysed. Plastic containers and automotive plastics (e.g. bumpers, headlamp lenses) were subjected to Fourier transform infrared spectrometry and car paints were analysed using Raman spectroscopy. In the forensic context analytical results must be interpreted and reported according to the standards of the interpretation schemes acknowledged in forensic sciences using the likelihood ratio approach. However, for proper construction of LR models for highly multivariate data, such as spectra, chemometric tools must be employed for substantial data compression. Conversion from classical feature representation to distance representation was proposed for revealing hidden data peculiarities and linear discriminant analysis was further applied for minimising the within-sample variability while maximising the between-sample variability. Both techniques enabled substantial reduction of data dimensionality. Univariate and multivariate likelihood ratio models were proposed for such data. It was shown that the combination of chemometric tools and the likelihood ratio approach is capable of solving the comparison problem of highly multivariate and correlated data after proper extraction of the most relevant features and variance information hidden in the data structure. Copyright © 2016 Elsevier B.V. All rights reserved.

A Multivariate Genome-Wide Association Analysis of 10 LDL Subfractions, and Their Response to Statin Treatment, in 1868 Caucasians

PubMed Central

Shim, Heejung; Chasman, Daniel I.; Smith, Joshua D.; Mora, Samia; Ridker, Paul M.; Nickerson, Deborah A.; Krauss, Ronald M.; Stephens, Matthew

2015-01-01

We conducted a genome-wide association analysis of 7 subfractions of low density lipoproteins (LDLs) and 3 subfractions of intermediate density lipoproteins (IDLs) measured by gradient gel electrophoresis, and their response to statin treatment, in 1868 individuals of European ancestry from the Pharmacogenomics and Risk of Cardiovascular Disease study. Our analyses identified four previously-implicated loci (SORT1, APOE, LPA, and CETP) as containing variants that are very strongly associated with lipoprotein subfractions (log10Bayes Factor > 15). Subsequent conditional analyses suggest that three of these (APOE, LPA and CETP) likely harbor multiple independently associated SNPs. Further, while different variants typically showed different characteristic patterns of association with combinations of subfractions, the two SNPs in CETP show strikingly similar patterns - both in our original data and in a replication cohort - consistent with a common underlying molecular mechanism. Notably, the CETP variants are very strongly associated with LDL subfractions, despite showing no association with total LDLs in our study, illustrating the potential value of the more detailed phenotypic measurements. In contrast with these strong subfraction associations, genetic association analysis of subfraction response to statins showed much weaker signals (none exceeding log10Bayes Factor of 6). However, two SNPs (in APOE and LPA) previously-reported to be associated with LDL statin response do show some modest evidence for association in our data, and the subfraction response proles at the LPA SNP are consistent with the LPA association, with response likely being due primarily to resistance of Lp(a) particles to statin therapy. An additional important feature of our analysis is that, unlike most previous analyses of multiple related phenotypes, we analyzed the subfractions jointly, rather than one at a time. Comparisons of our multivariate analyses with standard univariate analyses demonstrate that multivariate analyses can substantially increase power to detect associations. Software implementing our multivariate analysis methods is available at http://stephenslab.uchicago.edu/software.html. PMID:25898129

Conflict, Displacement, and IPV: Findings From Two Congolese Refugee Camps in Rwanda.

PubMed

Wako, Etobssie; Elliott, Leah; De Jesus, Stacy; Zotti, Marianne E; Swahn, Monica H; Beltrami, John

2015-09-01

This study describes the prevalence and correlates of past-year intimate partner violence (IPV) among displaced women. We used bivariate and multivariate analyses to assess the relationships between IPV and select variables of interest. Multivariate logistic regression modeling revealed that women who had experienced outsider violence were 11 times as likely (adjusted odds ratio [AOR] = 11.21; confidence interval, CI [5.25, 23.96]) to have reported IPV than women who had not experienced outsider violence. IPV in conflict-affected settings is a major public health concern that requires effective interventions; our results suggest that women who had experienced outsider violence are at greater risk of IPV. © The Author(s) 2015.

Role of Sleep Disturbance, Depression, Obesity, and Physical Inactivity in Fatigue in Rheumatoid Arthritis.

PubMed

Katz, Patricia; Margaretten, Mary; Trupin, Laura; Schmajuk, Gabriela; Yazdany, Jinoos; Yelin, Edward

2016-01-01

Fatigue is a major concern for individuals with rheumatoid arthritis (RA). However, in order to treat fatigue adequately, its sources need to be identified. Data were collected during a single home visit (number of participants = 158). All participants had physician-diagnosed RA. Assessments of self-reported sleep quality, depression, physical activity, RA disease activity, muscle strength, functional limitations, and body composition were made. Information on demographics, medications, and smoking was collected. The Fatigue Severity Inventory (FSI; measuring average fatigue over the past 7 days) was used as the primary outcome. Analyses were first conducted to evaluate bivariate relationships with fatigue. Correlations among risk factors were examined. Multivariate analyses identified independent predictors of fatigue. The mean ± SD age was 59 ± 11 years, the mean ± SD disease duration was 21 ± 13 years, and 85% of subjects were female. The mean ± SD FSI rating was 3.8 ± 2.0 (range 0-10). In multivariate analyses, self-reported disease activity, poor sleep, depression, and obesity were independently associated with fatigue. Physical inactivity was correlated with poor sleep, depression, and obesity. Mediation analyses indicated that physical inactivity had an indirect association with fatigue, mediated by poor sleep, depression, and obesity. This cross-sectional study suggests that fatigue may not be solely a result of RA disease activity, but may result from a constellation of factors that includes RA disease activity or pain, but also includes inactivity, depression, obesity, and poor sleep. The results suggest new avenues for interventions to improve fatigue in individuals with RA, such as increasing physical activity or addressing depression or obesity. © 2016, American College of Rheumatology.

Using multivariate generalizability theory to assess the effect of content stratification on the reliability of a performance assessment.

PubMed

Keller, Lisa A; Clauser, Brian E; Swanson, David B

2010-12-01

In recent years, demand for performance assessments has continued to grow. However, performance assessments are notorious for lower reliability, and in particular, low reliability resulting from task specificity. Since reliability analyses typically treat the performance tasks as randomly sampled from an infinite universe of tasks, these estimates of reliability may not be accurate. For tests built according to a table of specifications, tasks are randomly sampled from different strata (content domains, skill areas, etc.). If these strata remain fixed in the test construction process, ignoring this stratification in the reliability analysis results in an underestimate of "parallel forms" reliability, and an overestimate of the person-by-task component. This research explores the effect of representing and misrepresenting the stratification appropriately in estimation of reliability and the standard error of measurement. Both multivariate and univariate generalizability studies are reported. Results indicate that the proper specification of the analytic design is essential in yielding the proper information both about the generalizability of the assessment and the standard error of measurement. Further, illustrative D studies present the effect under a variety of situations and test designs. Additional benefits of multivariate generalizability theory in test design and evaluation are also discussed.

Selection Indices and Multivariate Analysis Show Similar Results in the Evaluation of Growth and Carcass Traits in Beef Cattle

PubMed Central

Brito Lopes, Fernando; da Silva, Marcelo Corrêa; Magnabosco, Cláudio Ulhôa; Goncalves Narciso, Marcelo; Sainz, Roberto Daniel

2016-01-01

This research evaluated a multivariate approach as an alternative tool for the purpose of selection regarding expected progeny differences (EPDs). Data were fitted using a multi-trait model and consisted of growth traits (birth weight and weights at 120, 210, 365 and 450 days of age) and carcass traits (longissimus muscle area (LMA), back-fat thickness (BF), and rump fat thickness (RF)), registered over 21 years in extensive breeding systems of Polled Nellore cattle in Brazil. Multivariate analyses were performed using standardized (zero mean and unit variance) EPDs. The k mean method revealed that the best fit of data occurred using three clusters (k = 3) (P < 0.001). Estimates of genetic correlation among growth and carcass traits and the estimates of heritability were moderate to high, suggesting that a correlated response approach is suitable for practical decision making. Estimates of correlation between selection indices and the multivariate index (LD1) were moderate to high, ranging from 0.48 to 0.97. This reveals that both types of indices give similar results and that the multivariate approach is reliable for the purpose of selection. The alternative tool seems very handy when economic weights are not available or in cases where more rapid identification of the best animals is desired. Interestingly, multivariate analysis allowed forecasting information based on the relationships among breeding values (EPDs). Also, it enabled fine discrimination, rapid data summarization after genetic evaluation, and permitted accounting for maternal ability and the genetic direct potential of the animals. In addition, we recommend the use of longissimus muscle area and subcutaneous fat thickness as selection criteria, to allow estimation of breeding values before the first mating season in order to accelerate the response to individual selection. PMID:26789008

Selection Indices and Multivariate Analysis Show Similar Results in the Evaluation of Growth and Carcass Traits in Beef Cattle.

PubMed

Brito Lopes, Fernando; da Silva, Marcelo Corrêa; Magnabosco, Cláudio Ulhôa; Goncalves Narciso, Marcelo; Sainz, Roberto Daniel

2016-01-01

This research evaluated a multivariate approach as an alternative tool for the purpose of selection regarding expected progeny differences (EPDs). Data were fitted using a multi-trait model and consisted of growth traits (birth weight and weights at 120, 210, 365 and 450 days of age) and carcass traits (longissimus muscle area (LMA), back-fat thickness (BF), and rump fat thickness (RF)), registered over 21 years in extensive breeding systems of Polled Nellore cattle in Brazil. Multivariate analyses were performed using standardized (zero mean and unit variance) EPDs. The k mean method revealed that the best fit of data occurred using three clusters (k = 3) (P < 0.001). Estimates of genetic correlation among growth and carcass traits and the estimates of heritability were moderate to high, suggesting that a correlated response approach is suitable for practical decision making. Estimates of correlation between selection indices and the multivariate index (LD1) were moderate to high, ranging from 0.48 to 0.97. This reveals that both types of indices give similar results and that the multivariate approach is reliable for the purpose of selection. The alternative tool seems very handy when economic weights are not available or in cases where more rapid identification of the best animals is desired. Interestingly, multivariate analysis allowed forecasting information based on the relationships among breeding values (EPDs). Also, it enabled fine discrimination, rapid data summarization after genetic evaluation, and permitted accounting for maternal ability and the genetic direct potential of the animals. In addition, we recommend the use of longissimus muscle area and subcutaneous fat thickness as selection criteria, to allow estimation of breeding values before the first mating season in order to accelerate the response to individual selection.

Ten Facts about Tuition at Independent Colleges and Universities. A Report from the National Association of Independent Colleges and Universities.

ERIC Educational Resources Information Center

National Association of Independent Colleges and Universities, Washington, DC.

This report seeks to explain the complex relationship between "cost" and "price" at independent private colleges and universities, and to demonstrate that federal student financial aid does not contribute to tuition and fee increases at such institutions. To support these results, 10 facts, drawn from multivariate statistical analyses of data from…

Effects of Flavor and Texture on the Sensory Perception of Gouda-Type Cheese Varieties during Ripening Using Multivariate Analysis.

PubMed

Shiota, Makoto; Iwasawa, Ai; Suzuki-Iwashima, Ai; Iida, Fumiko

2015-12-01

The impact of flavor composition, texture, and other factors on desirability of different commercial sources of Gouda-type cheese using multivariate analyses on the basis of sensory and instrumental analyses were investigated. Volatile aroma compounds were measured using headspace solid-phase microextraction gas chromatography/mass spectrometry (GC/MS) and steam distillation extraction (SDE)-GC/MS, and fatty acid composition, low-molecular-weight compounds, including amino acids, and organic acids, as well pH, texture, and color were measured to determine their relationship with sensory perception. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was performed to discriminate between 2 different ripening periods in 7 sample sets, revealing that ethanol, ethyl acetate, hexanoic acid, and octanoic acid increased with increasing sensory attribute scores for sweetness, fruity, and sulfurous. A partial least squares (PLS) regression model was constructed to predict the desirability of cheese using these parameters. We showed that texture and buttery flavors are important factors affecting the desirability of Gouda-type cheeses for Japanese consumers using these multivariate analyses. © 2015 Institute of Food Technologists®

Stature and jumping height are required in female volleyball, but motor coordination is a key factor for future elite success.

PubMed

Pion, Johan A; Fransen, Job; Deprez, Dieter N; Segers, Veerle I; Vaeyens, Roel; Philippaerts, Renaat M; Lenoir, Matthieu

2015-06-01

It was hypothesized that differences in anthropometry, physical performance, and motor coordination would be found between Belgian elite and sub-elite level female volleyball players using a retrospective analysis of test results gathered over a 5-year period. The test sample in this study consisted of 21 young female volleyball players (15.3 ± 1.5 years) who were selected to train at the Flemish Top Sports Academy for Volleyball in 2008. All players (elite, n = 13; sub-elite, n = 8) were included in the same talent development program, and the elite-level athletes were of a high to very high performance levels according to European competition level in 2013. Five multivariate analyses of variance were used. There was no significant effect of playing level on measures of anthropometry (F = 0.455, p = 0.718, (Equation is included in full-text article.)= 0.07), flexibility (F = 1.861, p = 0.188, (Equation is included in full-text article.)= 0.19), strength (F = 1.218, p = 0.355, (Equation is included in full-text article.)= 0.32); and speed and agility (F = 1.176, p = 0.350, (Equation is included in full-text article.)= 0.18). Multivariate analyses of variance revealed significant multivariate effects between playing levels for motor coordination (F = 3.470, p = 0.036, (Equation is included in full-text article.)= 0.59). A Mann-Whitney U test and a sequential discriminant analysis confirmed these results. Previous research revealed that stature and jump height are prerequisites for talent identification in female volleyball. In addition, the results show that motor coordination is an important factor in determining inclusion into the elite level in female volleyball.

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

Speed of response in ultrabrief and brief pulse width right unilateral ECT.

PubMed

Loo, Colleen K; Garfield, Joshua B B; Katalinic, Natalie; Schweitzer, Isaac; Hadzi-Pavlovic, Dusan

2013-05-01

Ultrabrief pulse width stimulation electroconvulsive therapy (ECT) results in less cognitive side-effects than brief pulse ECT, but recent work suggests that more treatment sessions may be required to achieve similar efficacy. In this retrospective analysis of subjects pooled from three research studies, time to improvement was analysed in 150 depressed subjects who received right unilateral ECT with a brief pulse width (at five times seizure threshold) or ultrabrief pulse width (at six times seizure threshold). Multivariate Cox regression analyses compared the number of treatments required for 50% reduction in depression scores (i.e. speed of response) in these two samples. The analyses controlled for clinical, demographic and treatment variables that differed between the samples or that were found to be significant predictors of speed of response in univariate analyses. In the multivariate analysis, older age predicted faster speed of response. There was a non-significant trend for faster time to 50% improvement with brief pulse ECT (p = 0.067). Remission rates were higher after brief pulse ECT than ultrabrief pulse ECT (p = 0.007) but response rates were similar. This study, the largest of its kind reported to date, suggests that fewer treatments may be needed to attain response with brief than ultrabrief pulse ECT and that remission rates are higher with brief pulse ECT. Further research with a larger randomized and blinded study is recommended.

Mortality Prediction Model of Septic Shock Patients Based on Routinely Recorded Data

PubMed Central

Carrara, Marta; Baselli, Giuseppe; Ferrario, Manuela

2015-01-01

We studied the problem of mortality prediction in two datasets, the first composed of 23 septic shock patients and the second composed of 73 septic subjects selected from the public database MIMIC-II. For each patient we derived hemodynamic variables, laboratory results, and clinical information of the first 48 hours after shock onset and we performed univariate and multivariate analyses to predict mortality in the following 7 days. The results show interesting features that individually identify significant differences between survivors and nonsurvivors and features which gain importance only when considered together with the others in a multivariate regression model. This preliminary study on two small septic shock populations represents a novel contribution towards new personalized models for an integration of multiparameter patient information to improve critical care management of shock patients. PMID:26557154

Application of multivariate statistical techniques in microbial ecology.

PubMed

Paliy, O; Shankar, V

2016-03-01

Recent advances in high-throughput methods of molecular analyses have led to an explosion of studies generating large-scale ecological data sets. In particular, noticeable effect has been attained in the field of microbial ecology, where new experimental approaches provided in-depth assessments of the composition, functions and dynamic changes of complex microbial communities. Because even a single high-throughput experiment produces large amount of data, powerful statistical techniques of multivariate analysis are well suited to analyse and interpret these data sets. Many different multivariate techniques are available, and often it is not clear which method should be applied to a particular data set. In this review, we describe and compare the most widely used multivariate statistical techniques including exploratory, interpretive and discriminatory procedures. We consider several important limitations and assumptions of these methods, and we present examples of how these approaches have been utilized in recent studies to provide insight into the ecology of the microbial world. Finally, we offer suggestions for the selection of appropriate methods based on the research question and data set structure. © 2016 John Wiley & Sons Ltd.

Probabilistic, meso-scale flood loss modelling

NASA Astrophysics Data System (ADS)

Kreibich, Heidi; Botto, Anna; Schröter, Kai; Merz, Bruno

2016-04-01

Flood risk analyses are an important basis for decisions on flood risk management and adaptation. However, such analyses are associated with significant uncertainty, even more if changes in risk due to global change are expected. Although uncertainty analysis and probabilistic approaches have received increased attention during the last years, they are still not standard practice for flood risk assessments and even more for flood loss modelling. State of the art in flood loss modelling is still the use of simple, deterministic approaches like stage-damage functions. Novel probabilistic, multi-variate flood loss models have been developed and validated on the micro-scale using a data-mining approach, namely bagging decision trees (Merz et al. 2013). In this presentation we demonstrate and evaluate the upscaling of the approach to the meso-scale, namely on the basis of land-use units. The model is applied in 19 municipalities which were affected during the 2002 flood by the River Mulde in Saxony, Germany (Botto et al. submitted). The application of bagging decision tree based loss models provide a probability distribution of estimated loss per municipality. Validation is undertaken on the one hand via a comparison with eight deterministic loss models including stage-damage functions as well as multi-variate models. On the other hand the results are compared with official loss data provided by the Saxon Relief Bank (SAB). The results show, that uncertainties of loss estimation remain high. Thus, the significant advantage of this probabilistic flood loss estimation approach is that it inherently provides quantitative information about the uncertainty of the prediction. References: Merz, B.; Kreibich, H.; Lall, U. (2013): Multi-variate flood damage assessment: a tree-based data-mining approach. NHESS, 13(1), 53-64. Botto A, Kreibich H, Merz B, Schröter K (submitted) Probabilistic, multi-variable flood loss modelling on the meso-scale with BT-FLEMO. Risk Analysis.

TU-FG-201-05: Varian MPC as a Statistical Process Control Tool

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

Carver, A; Rowbottom, C

Purpose: Quality assurance in radiotherapy requires the measurement of various machine parameters to ensure they remain within permitted values over time. In Truebeam release 2.0 the Machine Performance Check (MPC) was released allowing beam output and machine axis movements to be assessed in a single test. We aim to evaluate the Varian Machine Performance Check (MPC) as a tool for Statistical Process Control (SPC). Methods: Varian’s MPC tool was used on three Truebeam and one EDGE linac for a period of approximately one year. MPC was commissioned against independent systems. After this period the data were reviewed to determine whethermore » or not the MPC was useful as a process control tool. Analyses on individual tests were analysed using Shewhart control plots, using Matlab for analysis. Principal component analysis was used to determine if a multivariate model was of any benefit in analysing the data. Results: Control charts were found to be useful to detect beam output changes, worn T-nuts and jaw calibration issues. Upper and lower control limits were defined at the 95% level. Multivariate SPC was performed using Principal Component Analysis. We found little evidence of clustering beyond that which might be naively expected such as beam uniformity and beam output. Whilst this makes multivariate analysis of little use it suggests that each test is giving independent information. Conclusion: The variety of independent parameters tested in MPC makes it a sensitive tool for routine machine QA. We have determined that using control charts in our QA programme would rapidly detect changes in machine performance. The use of control charts allows large quantities of tests to be performed on all linacs without visual inspection of all results. The use of control limits alerts users when data are inconsistent with previous measurements before they become out of specification. A. Carver has received a speaker’s honorarium from Varian.« less

Incorporating Single-nucleotide Polymorphisms Into the Lyman Model to Improve Prediction of Radiation Pneumonitis

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

Tucker, Susan L., E-mail: sltucker@mdanderson.org; Li Minghuan; Xu Ting

2013-01-01

Purpose: To determine whether single-nucleotide polymorphisms (SNPs) in genes associated with DNA repair, cell cycle, transforming growth factor-{beta}, tumor necrosis factor and receptor, folic acid metabolism, and angiogenesis can significantly improve the fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model of radiation pneumonitis (RP) risk among patients with non-small cell lung cancer (NSCLC). Methods and Materials: Sixteen SNPs from 10 different genes (XRCC1, XRCC3, APEX1, MDM2, TGF{beta}, TNF{alpha}, TNFR, MTHFR, MTRR, and VEGF) were genotyped in 141 NSCLC patients treated with definitive radiation therapy, with or without chemotherapy. The LKB model was used to estimate the risk ofmore » severe (grade {>=}3) RP as a function of mean lung dose (MLD), with SNPs and patient smoking status incorporated into the model as dose-modifying factors. Multivariate analyses were performed by adding significant factors to the MLD model in a forward stepwise procedure, with significance assessed using the likelihood-ratio test. Bootstrap analyses were used to assess the reproducibility of results under variations in the data. Results: Five SNPs were selected for inclusion in the multivariate NTCP model based on MLD alone. SNPs associated with an increased risk of severe RP were in genes for TGF{beta}, VEGF, TNF{alpha}, XRCC1 and APEX1. With smoking status included in the multivariate model, the SNPs significantly associated with increased risk of RP were in genes for TGF{beta}, VEGF, and XRCC3. Bootstrap analyses selected a median of 4 SNPs per model fit, with the 6 genes listed above selected most often. Conclusions: This study provides evidence that SNPs can significantly improve the predictive ability of the Lyman MLD model. With a small number of SNPs, it was possible to distinguish cohorts with >50% risk vs <10% risk of RP when they were exposed to high MLDs.« less

An integrated phenomic approach to multivariate allelic association

PubMed Central

Medland, Sarah Elizabeth; Neale, Michael Churton

2010-01-01

The increased feasibility of genome-wide association has resulted in association becoming the primary method used to localize genetic variants that cause phenotypic variation. Much attention has been focused on the vast multiple testing problems arising from analyzing large numbers of single nucleotide polymorphisms. However, the inflation of experiment-wise type I error rates through testing numerous phenotypes has received less attention. Multivariate analyses can be used to detect both pleiotropic effects that influence a latent common factor, and monotropic effects that operate at a variable-specific levels, whilst controlling for non-independence between phenotypes. In this study, we present a maximum likelihood approach, which combines both latent and variable-specific tests and which may be used with either individual or family data. Simulation results indicate that in the presence of factor-level association, the combined multivariate (CMV) analysis approach performs well with a minimal loss of power as compared with a univariate analysis of a factor or sum score (SS). As the deviation between the pattern of allelic effects and the factor loadings increases, the power of univariate analyses of both factor and SSs decreases dramatically, whereas the power of the CMV approach is maintained. We show the utility of the approach by examining the association between dopamine receptor D2 TaqIA and the initiation of marijuana, tranquilizers and stimulants in data from the Add Health Study. Perl scripts that takes ped and dat files as input and produces Mx scripts and data for running the CMV approach can be downloaded from www.vipbg.vcu.edu/~sarahme/WriteMx. PMID:19707246

Acoustic neuroma: potential risk factors and audiometric surveillance in the aluminium industry

PubMed Central

Taiwo, Oyebode; Galusha, Deron; Tessier-Sherman, Baylah; Kirsche, Sharon; Cantley, Linda; Slade, Martin D; Cullen, Mark R; Donoghue, A Michael

2014-01-01

Objectives To look for an association between acoustic neuroma (AN) and participation in a hearing conservation programme (HCP) and also for an association between AN and possible occupational risk factors in the aluminium industry. Methods We conducted a case–control analysis of a population of US aluminium production workers in 8 smelters and 43 other plants. Using insurance claims data, 97 cases of AN were identified between 1996 and 2009. Each was matched with four controls. Covariates included participation in a HCP, working in an aluminium smelter, working in an electrical job and hearing loss. Results In the bivariate analyses, covariates associated with AN were participation in the HCP (OR=1.72; 95% CI 1.09 to 2.69) and smelter work (OR=1.88; 95% CI 1.06 to 3.36). Electrical work was not significant (OR=1.60; 95% CI 0.65 to 3.94). Owing to high participation in the HCP in smelters, multivariate subanalyses were required. In the multivariate analyses, participation in the HCP was the only statistically significant risk factor for AN. In the multivariate analysis restricted to employees not working in a smelter, the OR was 1.81 (95% CI 1.04 to 3.17). Hearing loss, an indirect measure of in-ear noise dose, was not predictive of AN. Conclusions Our results suggest the incidental detection of previously undiagnosed tumours in workers who participated in the company-sponsored HCP. The increased medical surveillance among this population of workers most likely introduced detection bias, leading to the identification of AN cases that would have otherwise remained undetected. PMID:25015928

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.

The analysis of morphometric data on rocky mountain wolves and artic wolves using statistical method

NASA Astrophysics Data System (ADS)

Ammar Shafi, Muhammad; Saifullah Rusiman, Mohd; Hamzah, Nor Shamsidah Amir; Nor, Maria Elena; Ahmad, Noor’ani; Azia Hazida Mohamad Azmi, Nur; Latip, Muhammad Faez Ab; Hilmi Azman, Ahmad

2018-04-01

Morphometrics is a quantitative analysis depending on the shape and size of several specimens. Morphometric quantitative analyses are commonly used to analyse fossil record, shape and size of specimens and others. The aim of the study is to find the differences between rocky mountain wolves and arctic wolves based on gender. The sample utilised secondary data which included seven variables as independent variables and two dependent variables. Statistical modelling was used in the analysis such was the analysis of variance (ANOVA) and multivariate analysis of variance (MANOVA). The results showed there exist differentiating results between arctic wolves and rocky mountain wolves based on independent factors and gender.

Dosimetric Predictors of Hypothyroidism After Radical Intensity-modulated Radiation Therapy for Non-metastatic Nasopharyngeal Carcinoma.

PubMed

Lee, V; Chan, Sum-Yin; Choi, Cheuk-Wai; Kwong, D; Lam, Ka-On; Tong, Chi-Chung; Sze, Chun-Kin; Ng, S; Leung, To-Wai; Lee, A

2016-08-01

To investigate dosimetric predictors of hypothyroidism after radical intensity-modulated radiation therapy (IMRT) for non-metastatic nasopharyngeal carcinoma (NPC). Patients with non-metastatic NPC treated with radical IMRT from 2008 to 2013 were reviewed. Serum thyroid function tests before and after IMRT were regularly monitored. Univariable and multivariable analyses were carried out for predictors of biochemical and clinical hypothyroidism. In total, 149 patients were recruited. After a median follow-up duration of 3.1 years, 33 (22.1%) and 21 (14.1%) patients developed biochemical and clinical hypothyroidism, respectively. Eight (24.2%) patients who had biochemical hypothyroidism developed clinical hypothyroidism later. Univariable and multivariable analyses revealed that the volume of the thyroid (P=0.002, multivariable), VS60 (the absolute thyroid volume spared from 60 Gy or less) (P<0.001, multivariable) and VS45 (P<0.001, multivariable) of the thyroid were significant predictors of biochemical hypothyroidism. The freedom from biochemical hypothyroidism was longer for those whose VS60 ≥ 10 cm(3) (mean 90.9 versus 62.6 months; P<0.001) and VS45 ≥ 5 cm(3) (mean 91.9 versus 65.2 months; P=0.001). Similarly multivariable analyses revealed that VS60 (P=0.001) and VS45 (P=0.003) were significant predictors of clinical hypothyroidism. The freedom from clinical hypothyroidism was longer for those whose VS60 ≥ 10 cm(3) (91.5 versus 73.3 months; P=0.002) and VS45 ≥ 5 cm(3) (91.5 versus 75.9 months; P=0.007). VS60 and VS45 of the thyroid should be considered important dose constraints against hypothyroidism without compromising target coverage during IMRT optimisation for NPC. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Prognostic Factors Affecting Locally Recurrent Rectal Cancer and Clinical Significance of Hemoglobin

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

Rades, Dirk; Kuhn, Hildegard; Schultze, Juergen

2008-03-15

Purpose: To investigate potential prognostic factors, including hemoglobin levels before and during radiotherapy, for associations with survival and local control in patients with unirradiated locally recurrent rectal cancer. Patients and Methods: Ten potential prognostic factors were investigated in 94 patients receiving radiotherapy for recurrent rectal cancer: age ({<=}68 vs. {>=}69 years), gender, Eastern Cooperative Oncology Group performance status (0-1 vs. 2-3), American Joint Committee on Cancer (AJCC) stage ({<=}II vs. III vs. IV), grading (G1-2 vs. G3), surgery, administration of chemotherapy, radiation dose (equivalent dose in 2-Gy fractions: {<=}50 vs. >50 Gy), and hemoglobin levels before (<12 vs. {>=}12 g/dL)more » and during (majority of levels: <12 vs. {>=}12 g/dL) radiotherapy. Multivariate analyses were performed, including hemoglobin levels, either before or during radiotherapy (not both) because these are confounding variables. Results: Improved survival was associated with better performance status (p < 0.001), lower AJCC stage (p = 0.023), surgery (p = 0.011), chemotherapy (p = 0.003), and hemoglobin levels {>=}12 g/dL both before (p = 0.031) and during (p < 0.001) radiotherapy. On multivariate analyses, performance status, AJCC stage, and hemoglobin levels during radiotherapy maintained significance. Improved local control was associated with better performance status (p = 0.040), lower AJCC stage (p = 0.010), lower grading (p = 0.012), surgery (p < 0.001), chemotherapy (p < 0.001), and hemoglobin levels {>=}12 g/dL before (p < 0.001) and during (p < 0.001) radiotherapy. On multivariate analyses, chemotherapy, grading, and hemoglobin levels before and during radiotherapy remained significant. Subgroup analyses of the patients having surgery demonstrated the extent of resection to be significantly associated with local control (p = 0.011) but not with survival (p = 0.45). Conclusion: Predictors for outcome in patients who received radiotherapy for locally recurrent rectal cancer were performance status, AJCC stage, chemotherapy, surgery, extent of resection, histologic grading, and hemoglobin levels both before and during radiotherapy.« less

Does speed matter? The impact of operative time on outcome in laparoscopic surgery

PubMed Central

Jackson, Timothy D.; Wannares, Jeffrey J.; Lancaster, R. Todd; Rattner, David W.

2012-01-01

Introduction Controversy exists concerning the importance of operative time on patient outcomes. It is unclear whether faster is better or haste makes waste or similarly whether slower procedures represent a safe, meticulous approach or inexperienced dawdling. The objective of the present study was to determine the effect of operative time on 30-day outcomes in laparoscopic surgery. Methods Patients who underwent laparoscopic general surgery procedures (colectomy, cholecystectomy, Nissen fundoplication, inguinal hernia, and gastric bypass) from the ACS-NSQIP 2005–2008 participant use file were identified. Exclusion criteria were defined a priori to identify same-day admission, elective procedures. Operative time was divided into deciles and summary statistics were analyzed. Univariate analyses using a Cochran-Armitage test for trend were completed. The effect of operative time on 30-day morbidity was further analyzed for each procedure type using multivariate regression controlling for case complexity and additional patient factors. Patients within the highest deciles were excluded to reduce outlier effect. Results A total of 76,748 elective general surgical patients who underwent laparoscopic procedures were analyzed. Univariate analyses of deciles of operative time demonstrated a statistically significant trend (p \\ 0.0001) toward increasing odds of complications with increasing operative time for laparoscopic colectomy (n = 10,135), cholecystectomy (n = 37,407), Nissen fundoplication (n = 4,934), and gastric bypass (n = 17,842). The trend was not found to be significant for laparoscopic inguinal hernia repair (n = 6,430; p = 0.14). Multivariate modeling revealed the effect of operative time to remain significant after controlling for additional patient factors. Conclusion Increasing operative time was associated with increased odds of complications and, therefore, it appears that speed may matter in laparoscopic surgery. These analyses are limited in their inability to adjust for all patient factors, potential confounders, and case complexities. Additional hierarchical multivariate analyses at the surgeon level would be important to examine this relationship further. PMID:21298533

Non-destructive analysis of the conformational differences among feedstock sources and their corresponding co-products from bioethanol production with molecular spectroscopy.

PubMed

Gamage, I H; Jonker, A; Zhang, X; Yu, P

2014-01-24

The objective of this study was to determine the possibility of using molecular spectroscopy with multivariate technique as a fast method to detect the source effects among original feedstock sources of wheat and their corresponding co-products, wheat DDGS, from bioethanol production. Different sources of the bioethanol feedstock and their corresponding bioethanol co-products, three samples per source, were collected from the same newly-built bioethanol plant with current bioethanol processing technology. Multivariate molecular spectral analyses were carried out using agglomerative hierarchical cluster analysis (AHCA) and principal component analysis (PCA). The molecular spectral data of different feedstock sources and their corresponding co-products were compared at four different regions of ca. 1800-1725 cm(-1) (carbonyl CO ester, mainly related to lipid structure conformation), ca. 1725-1482 cm(-1) (amide I and amide II region mainly related to protein structure conformation), ca. 1482-1180 cm(-1) (mainly associated with structural carbohydrate) and ca. 1180-800 cm(-1) (mainly related to carbohydrates) in complex plant-based system. The results showed that the molecular spectroscopy with multivariate technique could reveal the structural differences among the bioethanol feedstock sources and among their corresponding co-products. The AHCA and PCA analyses were able to distinguish the molecular structure differences associated with chemical functional groups among the different sources of the feedstock and their corresponding co-products. The molecular spectral differences indicated the differences in functional, biomolecular and biopolymer groups which were confirmed by wet chemical analysis. These biomolecular and biopolymer structural differences were associated with chemical and nutrient profiles and nutrient utilization and availability. Molecular spectral analyses had the potential to identify molecular structure difference among bioethanol feedstock sources and their corresponding co-products. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of intranasal oxytocin on symptoms of schizophrenia: A multivariate Bayesian meta-analysis.

PubMed

Williams, Donald R; Bürkner, Paul-Christian

2017-01-01

Schizophrenia is a heterogeneous disorder in which psychiatric symptoms are classified into two general subgroups-positive and negative symptoms. Current antipsychotic drugs are effective for treating positive symptoms, whereas negative symptoms are less responsive. Since the neuropeptide oxytocin (OT) has been shown to mediate social behavior in animals and humans, it has been used as an experimental therapeutic for treating schizophrenia and in particular negative symptoms which includes social deficits. Through eight randomized controlled trials (RCTs) and three meta-analyses, evidence for an effect of intranasal OT (IN-OT) has been inconsistent. We therefore conducted an updated meta-analysis that offers several advantages when compared to those done previously: (1) We used a multivariate analysis which allows for comparisons between symptoms and accounts for correlations between symptoms; (2) We controlled for baseline scores; (3) We used a fully Bayesian framework that allows for assessment of evidence in favor of the null hypothesis using Bayes factors; and (4) We addressed inconsistencies in the primary studies and previous meta-analyses. Eight RCTs (n=238) were included in the present study and we found that oxytocin did not improve any aspect of symptomology in schizophrenic patients and there was moderate evidence in favor of the null (no effect of oxytocin) for negative symptoms. Multivariate comparisons between symptom types revealed that oxytocin was not especially beneficial for treating negative symptoms. The effect size estimates were not moderated, publication bias was absent, and our estimates were robust to sensitivity analyses. These results suggest that IN-OT is not an effective therapeutic for schizophrenia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predicting microbiologically defined infection in febrile neutropenic episodes in children: global individual participant data multivariable meta-analysis

PubMed Central

Phillips, Robert S; Sung, Lillian; Amman, Roland A; Riley, Richard D; Castagnola, Elio; Haeusler, Gabrielle M; Klaassen, Robert; Tissing, Wim J E; Lehrnbecher, Thomas; Chisholm, Julia; Hakim, Hana; Ranasinghe, Neil; Paesmans, Marianne; Hann, Ian M; Stewart, Lesley A

2016-01-01

Background: Risk-stratified management of fever with neutropenia (FN), allows intensive management of high-risk cases and early discharge of low-risk cases. No single, internationally validated, prediction model of the risk of adverse outcomes exists for children and young people. An individual patient data (IPD) meta-analysis was undertaken to devise one. Methods: The ‘Predicting Infectious Complications in Children with Cancer' (PICNICC) collaboration was formed by parent representatives, international clinical and methodological experts. Univariable and multivariable analyses, using random effects logistic regression, were undertaken to derive and internally validate a risk-prediction model for outcomes of episodes of FN based on clinical and laboratory data at presentation. Results: Data came from 22 different study groups from 15 countries, of 5127 episodes of FN in 3504 patients. There were 1070 episodes in 616 patients from seven studies available for multivariable analysis. Univariable analyses showed associations with microbiologically defined infection (MDI) in many items, including higher temperature, lower white cell counts and acute myeloid leukaemia, but not age. Patients with osteosarcoma/Ewings sarcoma and those with more severe mucositis were associated with a decreased risk of MDI. The predictive model included: malignancy type, temperature, clinically ‘severely unwell', haemoglobin, white cell count and absolute monocyte count. It showed moderate discrimination (AUROC 0.723, 95% confidence interval 0.711–0.759) and good calibration (calibration slope 0.95). The model was robust to bootstrap and cross-validation sensitivity analyses. Conclusions: This new prediction model for risk of MDI appears accurate. It requires prospective studies assessing implementation to assist clinicians and parents/patients in individualised decision making. PMID:26954719

Non-destructive analysis of the conformational differences among feedstock sources and their corresponding co-products from bioethanol production with molecular spectroscopy

NASA Astrophysics Data System (ADS)

Gamage, I. H.; Jonker, A.; Zhang, X.; Yu, P.

2014-01-01

The objective of this study was to determine the possibility of using molecular spectroscopy with multivariate technique as a fast method to detect the source effects among original feedstock sources of wheat and their corresponding co-products, wheat DDGS, from bioethanol production. Different sources of the bioethanol feedstock and their corresponding bioethanol co-products, three samples per source, were collected from the same newly-built bioethanol plant with current bioethanol processing technology. Multivariate molecular spectral analyses were carried out using agglomerative hierarchical cluster analysis (AHCA) and principal component analysis (PCA). The molecular spectral data of different feedstock sources and their corresponding co-products were compared at four different regions of ca. 1800-1725 cm-1 (carbonyl Cdbnd O ester, mainly related to lipid structure conformation), ca. 1725-1482 cm-1 (amide I and amide II region mainly related to protein structure conformation), ca. 1482-1180 cm-1 (mainly associated with structural carbohydrate) and ca. 1180-800 cm-1 (mainly related to carbohydrates) in complex plant-based system. The results showed that the molecular spectroscopy with multivariate technique could reveal the structural differences among the bioethanol feedstock sources and among their corresponding co-products. The AHCA and PCA analyses were able to distinguish the molecular structure differences associated with chemical functional groups among the different sources of the feedstock and their corresponding co-products. The molecular spectral differences indicated the differences in functional, biomolecular and biopolymer groups which were confirmed by wet chemical analysis. These biomolecular and biopolymer structural differences were associated with chemical and nutrient profiles and nutrient utilization and availability. Molecular spectral analyses had the potential to identify molecular structure difference among bioethanol feedstock sources and their corresponding co-products.

Association Between Duration of Breast Feeding and Metabolic Syndrome: The Korean National Health and Nutrition Examination Surveys.

PubMed

Choi, Se Rin; Kim, Yong Min; Cho, Min Su; Kim, So Hyun; Shim, Young Suk

2017-04-01

This study aimed to evaluate the association of the lifelong duration of breast feeding with metabolic syndrome (MetS) and its components in Korean parous women aged 19-50 years. A total of 4724 participants from the Korean National Health and Nutritional Survey were included. Subjects were divided into four groups according to the duration of breast feeding: ≤5, 6-11, 12-23, or ≥24 months groups. The adjusted odds ratios (ORs) of MetS and its components were assessed according to the duration of breast feeding. Women who breastfed for 6-11 months had an OR of 0.67 (95% confidence interval [CI], 0.54-0.86) for elevated blood pressure (BP) compared with those who breastfed for ≤5 months after adjustment for possible confounders in a multivariable logistic regression analyses. Women who breastfed for 12-23 months were associated with an OR of 0.68 (95% CI, 0.54-0.86) for elevated BP, an OR of 0.78 (95% CI, 0.62-0.97) for elevated glucose, and an OR of 0.73 (95% CI, 0.56-0.95) for MetS compared with those who breastfed for ≤5 months in a multivariable logistic regression analyses. Women who breastfed for ≥24 months had an OR of 0.62 (95% CI, 0.52-0.84) for elevated glucose, an OR of 0.76 (95% CI, 0.60-0.96) for elevated triglycerides, and an OR of 0.70 (95% CI, 0.53-0.92) for MetS compared with those who breastfed for ≤5 months in a multivariable logistic regression analyses. Our results suggest that lifelong breast feeding for ≥12 months may be associated with lower risk for MetS.

Subtle but ubiquitous selection on body size in a natural population of collared flycatchers over 33 years.

PubMed

Björklund, M; Gustafsson, L

2017-07-01

Understanding the magnitude and long-term patterns of selection in natural populations is of importance, for example, when analysing the evolutionary impact of climate change. We estimated univariate and multivariate directional, quadratic and correlational selection on four morphological traits (adult wing, tarsus and tail length, body mass) over a time period of 33 years (≈ 19 000 observations) in a nest-box breeding population of collared flycatchers (Ficedula albicollis). In general, selection was weak in both males and females over the years regardless of fitness measure (fledged young, recruits and survival) with only few cases with statistically significant selection. When data were analysed in a multivariate context and as time series, a number of patterns emerged; there was a consistent, but weak, selection for longer wings in both sexes, selection was stronger on females when the number of fledged young was used as a fitness measure, there were no indications of sexually antagonistic selection, and we found a negative correlation between selection on tarsus and wing length in both sexes but using different fitness measures. Uni- and multivariate selection gradients were correlated only for wing length and mass. Multivariate selection gradient vectors were longer than corresponding vector of univariate gradients and had more constrained direction. Correlational selection had little importance. Overall, the fitness surface was more or less flat with few cases of significant curvature, indicating that the adaptive peak with regard to body size in this species is broader than the phenotypic distribution, which has resulted in weak estimates of selection. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Racial Differences in Circulating Natriuretic Peptide Levels: The Atherosclerosis Risk in Communities Study

PubMed Central

Gupta, Deepak K; Claggett, Brian; Wells, Quinn; Cheng, Susan; Li, Man; Maruthur, Nisa; Selvin, Elizabeth; Coresh, Josef; Konety, Suma; Butler, Kenneth R; Mosley, Thomas; Boerwinkle, Eric; Hoogeveen, Ron; Ballantyne, Christie M; Solomon, Scott D

2015-01-01

Background Natriuretic peptides promote natriuresis, diuresis, and vasodilation. Experimental deficiency of natriuretic peptides leads to hypertension (HTN) and cardiac hypertrophy, conditions more common among African Americans. Hospital-based studies suggest that African Americans may have reduced circulating natriuretic peptides, as compared to Caucasians, but definitive data from community-based cohorts are lacking. Methods and Results We examined plasma N-terminal pro B-type natriuretic peptide (NTproBNP) levels according to race in 9137 Atherosclerosis Risk in Communities (ARIC) Study participants (22% African American) without prevalent cardiovascular disease at visit 4 (1996–1998). Multivariable linear and logistic regression analyses were performed adjusting for clinical covariates. Among African Americans, percent European ancestry was determined from genetic ancestry informative markers and then examined in relation to NTproBNP levels in multivariable linear regression analysis. NTproBNP levels were significantly lower in African Americans (median, 43 pg/mL; interquartile range [IQR], 18, 88) than Caucasians (median, 68 pg/mL; IQR, 36, 124; P<0.0001). In multivariable models, adjusted log NTproBNP levels were 40% lower (95% confidence interval [CI], −43, −36) in African Americans, compared to Caucasians, which was consistent across subgroups of age, gender, HTN, diabetes, insulin resistance, and obesity. African-American race was also significantly associated with having nondetectable NTproBNP (adjusted OR, 5.74; 95% CI, 4.22, 7.80). In multivariable analyses in African Americans, a 10% increase in genetic European ancestry was associated with a 7% (95% CI, 1, 13) increase in adjusted log NTproBNP. Conclusions African Americans have lower levels of plasma NTproBNP than Caucasians, which may be partially owing to genetic variation. Low natriuretic peptide levels in African Americans may contribute to the greater risk for HTN and its sequalae in this population. PMID:25999400

Comparing lagged linear correlation, lagged regression, Granger causality, and vector autoregression for uncovering associations in EHR data.

PubMed

Levine, Matthew E; Albers, David J; Hripcsak, George

2016-01-01

Time series analysis methods have been shown to reveal clinical and biological associations in data collected in the electronic health record. We wish to develop reliable high-throughput methods for identifying adverse drug effects that are easy to implement and produce readily interpretable results. To move toward this goal, we used univariate and multivariate lagged regression models to investigate associations between twenty pairs of drug orders and laboratory measurements. Multivariate lagged regression models exhibited higher sensitivity and specificity than univariate lagged regression in the 20 examples, and incorporating autoregressive terms for labs and drugs produced more robust signals in cases of known associations among the 20 example pairings. Moreover, including inpatient admission terms in the model attenuated the signals for some cases of unlikely associations, demonstrating how multivariate lagged regression models' explicit handling of context-based variables can provide a simple way to probe for health-care processes that confound analyses of EHR data.

Metabolite profiling of Clinacanthus nutans leaves extracts obtained from different drying methods by 1H NMR-based metabolomics

NASA Astrophysics Data System (ADS)

Hashim, Noor Haslinda Noor; Latip, Jalifah; Khatib, Alfi

2016-11-01

The metabolites of Clinacanthus nutans leaves extracts and their dependence on drying process were systematically characterized using 1H nuclear magnetic resonance spectroscopy (NMR) multivariate data analysis. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were able to distinguish the leaves extracts obtained from different drying methods. The identified metabolites were carbohydrates, amino acid, flavonoids and sulfur glucoside compounds. The major metabolites responsible for the separation in PLS-DA loading plots were lupeol, cycloclinacosides, betulin, cerebrosides and choline. The results showed that the combination of 1H NMR spectroscopy and multivariate data analyses could act as an efficient technique to understand the C. nutans composition and its variation.

A Multivariate Genetic Analysis of Specific Phobia, Separation Anxiety and Social Phobia in Early Childhood

ERIC Educational Resources Information Center

Eley, Thalia C.; Rijsdijk, Fruhling V.; Perrin, Sean; O'Connor, Thomas G.; Bolton, Derek

2008-01-01

Background: Comorbidity amongst anxiety disorders is very common in children as in adults and leads to considerable distress and impairment, yet is poorly understood. Multivariate genetic analyses can shed light on the origins of this comorbidity by revealing whether genetic or environmental risks for one disorder also influence another. We…

The rate of country-level improvements of the infant mortality rate is mainly determined by previous history.

PubMed

Bremberg, Sven G

2016-08-01

Studies of country-level determinants of health have produced conflicting results even when the analyses have been restricted to high-income counties. Yet, most of these studies have not taken historical, country-specific developments into account. Thus, it is appropriate to separate the influence of current exposures from historical aspects. Determinants of the infant mortality rate (IMR) were studied in 28 OECD countries over the period 1990-2012. Twelve determinants were selected. They refer to the level of general resources, resources that specifically address child health and characteristics that affect knowledge dissemination, including level of trust, and a health related behaviour: the rate of female smoking. Bivariate analyses with the IMR in year 2000 as outcome and the 12 determinants produced six statistically significant models. In multivariate analyses, the rate of decrease in the IMR was investigated as outcome and a history variable (IMR in 1990) was included in the models. The history variable alone explained 95% of the variation. None of the multivariate models, with the 12 determinants included, explained significantly more variation. Taking into account the historical development of the IMR will critically affect correlations between country-level determinants and the IMR. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Factors associated with a second deferral among donors eligible for re-entry after a false-positive screening test for syphilis, HCV, HBV and HIV.

PubMed

Grégoire, Y; Germain, M; Delage, G

2018-05-01

Since 25 May 2010, all donors at our blood centre who tested false-positive for HIV, HBV, HCV or syphilis are eligible for re-entry after further testing. Donors who have a second false-positive screening test, either during qualification for or after re-entry, are deferred for life. This study reports on factors associated with the occurrence of such deferrals. Rates of second false-positive results were compared by year of deferral, transmissible disease marker, gender, age, donor status (new or repeat) and testing platform (same or different) both at qualification for re-entry and afterwards. Chi-square tests were used to compare proportions. Cox regression was used for multivariate analyses. Participation rates in the re-entry programme were 42·1%: 25·6% failed to qualify for re-entry [different platform: 2·7%; same platform: 42·9% (P < 0·0001)]. After re-entry, rates of deferral for second false-positive results were 8·4% after 3 years [different platform: 1·8%; same platform: 21·4% (P < 0·0001)]. Deferral rates were higher for HIV and HCV than for HBV at qualification when tested on the same platform. The risk, when analysed by multivariate analyses, of a second deferral for a false-positive result, both at qualification and 3 years after re-entry, was lower for donors deferred on a different platform; this risk was higher for HIV, HCV and syphilis than for HBV and for new donors if tested on the same platform. Re-entry is more often successful when donors are tested on a testing platform different from the one on which they obtained their first false-positive result. © 2018 International Society of Blood Transfusion.

Methods for estimating confidence intervals in interrupted time series analyses of health interventions.

PubMed

Zhang, Fang; Wagner, Anita K; Soumerai, Stephen B; Ross-Degnan, Dennis

2009-02-01

Interrupted time series (ITS) is a strong quasi-experimental research design, which is increasingly applied to estimate the effects of health services and policy interventions. We describe and illustrate two methods for estimating confidence intervals (CIs) around absolute and relative changes in outcomes calculated from segmented regression parameter estimates. We used multivariate delta and bootstrapping methods (BMs) to construct CIs around relative changes in level and trend, and around absolute changes in outcome based on segmented linear regression analyses of time series data corrected for autocorrelated errors. Using previously published time series data, we estimated CIs around the effect of prescription alerts for interacting medications with warfarin on the rate of prescriptions per 10,000 warfarin users per month. Both the multivariate delta method (MDM) and the BM produced similar results. BM is preferred for calculating CIs of relative changes in outcomes of time series studies, because it does not require large sample sizes when parameter estimates are obtained correctly from the model. Caution is needed when sample size is small.

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

Housing Status and HIV Risk Behaviors among Transgender Women in Los Angeles

PubMed Central

Fletcher, Jesse B.; Kisler, Kimberly A.; Reback, Cathy J.

2014-01-01

Due to social stigma, lack of social support, and minimal legal employment opportunities, transgender women (transwomen) face elevated rates of unstable housing. This study examined the association between housing status and HIV risk behaviors among 517 transwomen encountered through street outreach. Seven variables (including sociodemographics, HIV status, housing status, and sexual partner type) were used to estimate partial associations during multivariable analyses; housing status was coded trichotomously (housed, marginally housed, and homeless) for these analyses. Results demonstrated that homeless and marginally housed transwomen engaged in significantly higher rates of illicit drug use than housed transwomen; however, marginally housed and housed transwomen engaged in significantly higher rates of illegal hormone injections than homeless transwomen. Rates of sex work were high in the sample as a whole, though sex with an exchange partner was most common among the marginally housed transwomen. Multivariate logistic regression revealed that unstable housing moderated the association between HIV status and engagement in unprotected serodiscordant anal intercourse. The marginally housed transwomen exhibited the greatest risk profile for HIV acquisition or transmission. PMID:25190499

Breastfeeding difficulties and exclusivity among late preterm and term infants: results from the all our babies study.

PubMed

Nagulesapillai, Tharsiya; McDonald, Sheila W; Fenton, Tanis R; Mercader, Hannah Faye G; Tough, Suzanne C

2013-07-25

To compare breastfeeding difficulties attributable to the baby and mother/milk and exclusive breastfeeding between a group of late preterm (LP) infants and term infants. We utilized data from a prospective community-based cohort (n=2977) in Calgary, Alberta, and performed bivariate and multivariable analyses to identify demographic, obstetric, maternal and infant health indicators that were independently associated with term status and breastfeeding outcomes. Multivariable analyses found that LP status was an independent risk factor for breastfeeding difficulties attributable to the baby (OR 1.72, 95% CI 1.24-2.38), but not for difficulties due to mother/milk (defined as not producing enough milk or having flat or inverted nipples). Among women who were breastfeeding at hospital discharge, mothers of LP infants were less likely to report exclusive breastfeeding at 4 months (OR 0.67, 95% CI 0.46-0.97), after controlling for household income level, mode of delivery and postpartum maternal physical health. Mothers of LP infants need increased support to establish successful breastfeeding outcomes and to ensure that these infants receive the full benefits of breast milk.

Predictors of Low Back Pain Onset in a Prospective British Study

PubMed Central

Power, Chris; Frank, John; Hertzman, Clyde; Schierhout, Gill; Li, Leah

2001-01-01

Objectives. This study examined predictors of low back pain onset in a British birth cohort. Methods. Univariate and multivariate analyses focused on individuals who experienced onset of low back pain at 32 to 33 years of age (n= 571) and individuals who were pain free (n = 5210). Participants were members of the 1958 British birth cohort. Results. Incident pain was elevated among those with psychological distress at 23 years of age (adjusted odds ratio [OR] = 2.52, 95% confidence interval [CI] = 1.65, 3.86) and among persistent moderate or heavy smokers (adjusted OR = 1.63, 95% CI = 1.23, 2.17). Significant univariate associations involving other factors (e.g., social class, childhood emotional status, body mass index, job satisfaction) did not persist in multivariate analyses. Conclusions. This prospectively studied cohort provides evidence that psychological distress more than doubles later risk of low back pain, with smoking having a modest independent effect. Other prospective studies are needed to confirm these findings before implications for low back pain prevention can be assessed. PMID:11574334

Anthropometrics and prognosis in diffuse large B-cell lymphoma: a multicentre study of 653 patients.

PubMed

Bendtsen, Mette Dahl; Munksgaard, Peter Svenssen; Severinsen, Marianne Tang; Bekric, Eric; Brieghel, Christian; Nielsen, Kristina Buchardi; Brown, Peter de Nully; Dybkaer, Karen; Johnsen, Hans Erik; Bøgsted, Martin; El-Galaly, Tarec Christoffer

2017-04-01

The impact of body mass index (BMI) and body surface area (BSA) on survival in diffuse large B-cell lymphoma (DLBCL) is controversial. Recent studies show superior outcomes for overweight and obese patients. A total of 653 R-CHOP(-like)-treated DLBCL patients were included in this retrospective cohort study. Patients, baseline clinicopathologic characteristics and treatment information were retrieved from the Danish Lymphoma Registry. Anthropometric measures were obtained from chemotherapy prescription charts. Underweight (BMI <18.5 kg/m 2 ) was associated with significantly worse progression-free survival (PFS) for male patients only in sex-stratified analyses (HR 3.92, 95% CI: 1.57-9.75, P = 0.003, for males; HR 1.65, 95% CI: 0.90-3.02, P = 0.107, for females). In multivariate analyses, underweight was associated with worse PFS for both sexes (HR 5.34, 95% CI: 2.07-13.79, P = 0.001, for males; HR 2.14, 95% CI: 1.12-4.08, P = 0.021, for females). Similar results were obtained in analyses of overall survival. In crude analyses, BSA <1.8 m 2 was associated with worse PFS for men and women (HR 1.65, 95% CI: 1.03-2.65, P = 0.039, for men; HR 1.62, 95% CI: 1.03-2.56, P = 0.037, for women). In multivariate analyses, however, these associations diminished. Our study demonstrates that underweight DLBCL patients have worse outcomes following R-CHOP as compared to normal as well as overweight patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Collagen Triple Helix Repeat Containing-1 (CTHRC1) Expression in Oral Squamous Cell Carcinoma (OSCC): Prognostic Value and Clinico-Pathological Implications

PubMed Central

Lee, Chia Ee; Vincent-Chong, Vui King; Ramanathan, Anand; Kallarakkal, Thomas George; Karen-Ng, Lee Peng; Ghani, Wan Maria Nabillah; Rahman, Zainal Ariff Abdul; Ismail, Siti Mazlipah; Abraham, Mannil Thomas; Tay, Keng Kiong; Mustafa, Wan Mahadzir Wan; Cheong, Sok Ching; Zain, Rosnah Binti

2015-01-01

BACKGROUND: Collagen Triple Helix Repeat Containing 1 (CTHRC1) is a protein often found to be over-expressed in various types of human cancers. However, correlation between CTHRC1 expression level with clinico-pathological characteristics and prognosis in oral cancer remains unclear. Therefore, this study aimed to determine mRNA and protein expression of CTHRC1 in oral squamous cell carcinoma (OSCC) and to evaluate the clinical and prognostic impact of CTHRC1 in OSCC. METHODS: In this study, mRNA and protein expression of CTHRC1 in OSCCs were determined by quantitative PCR and immunohistochemistry, respectively. The association between CTHRC1 and clinico-pathological parameters were evaluated by univariate and multivariate binary logistic regression analyses. Correlation between CTHRC1 protein expressions with survival were analysed using Kaplan-Meier and Cox regression models. RESULTS: Current study demonstrated CTHRC1 was significantly overexpressed at the mRNA level in OSCC. Univariate analyses indicated a high-expression of CTHRC1 that was significantly associated with advanced stage pTNM staging, tumour size ≥ 4 cm and positive lymph node metastasis (LNM). However, only positive LNM remained significant after adjusting with other confounder factors in multivariate logistic regression analyses. Kaplan-Meier survival analyses and Cox model demonstrated that patients with high-expression of CTHRC1 protein were associated with poor prognosis and is an independent prognostic factor in OSCC. CONCLUSION: This study indicated that over-expression of CTHRC1 potentially as an independent predictor for positive LNM and poor prognosis in OSCC. PMID:26664254

Disproportionality and Learning Disabilities: Parsing Apart Race, Socioeconomic Status, and Language

PubMed Central

Shifrer, Dara; Muller, Chandra; Callahan, Rebecca

2014-01-01

The disproportionate identification of learning disabilities among certain socio-demographic subgroups, typically groups who are already disadvantaged, is perceived as a persistent problem within the education system. The academic and social experiences of students who are misidentified with a learning disability may be severely restricted, while students with a learning disability who are never identified are less likely to receive the accommodations and modifications necessary to learn at their maximum potential. We use the Education Longitudinal Study of 2002 to describe national patterns in learning disability identification. Results indicate that socio-demographic characteristics are predictive of identification with a learning disability. While some conventional areas of disproportionality are confirmed (males and language minorities), differences in SES entirely account for African-American and Hispanic disproportionality. Discrepancy between the results of bivariate and multivariate analyses confirms the importance of employing multivariate multilevel models in investigation of disproportionality. PMID:20587753

Relationship Between Central and Peripheral Atherosclerosis and Left Ventricular Dysfunction in a Community Population

PubMed Central

Tsao, Connie W.; Gona, Philimon; Salton, Carol; Murabito, Joanne M.; Oyama, Noriko; Danias, Peter G.; O’Donnell, Christopher J.; Manning, Warren J.; Yeon, Susan B.

2011-01-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and PAD in a community cohort. 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65±9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional LV systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at Examination 7. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p<0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p<0.001) and volume of aortic plaque were associated with decreased ABI (p<0.001). After multivariable adjustment, ABI≤0.9 or prior revascularization was associated with a three-fold odds of aortic plaque (p=0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p<0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment suggesting shared mechanisms beyond those captured by traditional risk factors. PMID:21708875

The association of serum prolactin concentration with inflammatory biomarkers - cross-sectional findings from the population-based Study of Health in Pomerania.

PubMed

Friedrich, Nele; Schneider, Harald J; Spielhagen, Christin; Markus, Marcello Ricardo Paulista; Haring, Robin; Grabe, Hans J; Buchfelder, Michael; Wallaschofski, Henri; Nauck, Matthias

2011-10-01

Prolactin (PRL) is involved in immune regulation and may contribute to an atherogenic phenotype. Previous results on the association of PRL with inflammatory biomarkers have been conflicting and limited by small patient studies. Therefore, we used data from a large population-based sample to assess the cross-sectional associations between serum PRL concentration and high-sensitivity C-reactive protein (hsCRP), fibrinogen, interleukin-6 (IL-6), and white blood cell (WBC) count. From the population-based Study of Health in Pomerania (SHIP), a total of 3744 subjects were available for the present analyses. PRL and inflammatory biomarkers were measured. Linear and logistic regression models adjusted for age, sex, body-mass-index, total cholesterol and glucose were analysed. Multivariable linear regression models revealed a positive association of PRL with WBC. Multivariable logistic regression analyses showed a significant association of PRL with increased IL-6 in non-smokers [highest vs lowest quintile: odds ratio 1·69 (95% confidence interval 1·10-2·58), P = 0·02] and smokers [OR 2·06 (95%-CI 1·10-3·89), P = 0·02]. Similar results were found for WBC in non-smokers [highest vs lowest quintile: OR 2·09 (95%-CI 1·21-3·61), P = 0·01)] but not in smokers. Linear and logistic regression analyses revealed no significant associations of PRL with hsCRP or fibrinogen. Serum PRL concentrations are associated with inflammatory biomarkers including IL-6 and WBC, but not hsCRP or fibrinogen. The suggested role of PRL in inflammation needs further investigation in future prospective studies. © 2011 Blackwell Publishing Ltd.

HPV infection among a population-based sample of sexual minority women from USA

PubMed Central

Reiter, Paul L; McRee, Annie-Laurie

2017-01-01

Objectives Sexual minority women are at risk for infection with human papillomavirus (HPV); yet, relatively little is known about the prevalence of HPV infection among this population. Methods We analysed data from the 2003–2012 National Health and Nutrition Examination Survey among women aged 20–59 (n=7132). We examined two dimensions of sexual orientation (sexual identity and sexual behaviour) and used weighted logistic regression to determine how HPV infection outcomes (any HPV type, high-risk HPV type and vaccine HPV type) vary by dimension. Results Similar patterns emerged for sexual identity and sexual behaviour. In bivariate analyses, HPV infection outcomes were more common among non-heterosexual women compared with heterosexual women (any type: 49.7% vs 41.1%; high-risk type: 37.0% vs 27.9%), as well as among women who reported any same-sex partners compared with women who reported only opposite-sex partners (any type: 55.9% vs 41.0%; high-risk type: 37.7% vs 28.2%; vaccine type: 19.1% vs 14.0%) (p<0.05). When we disaggregated measures of sexual orientation into subgroups, bisexual women and women who reported partners of both sexes had greater odds of HPV infection outcomes (p<0.05 in bivariate analyses). Multivariate models attenuated several of these differences, though lesbian women and women who reported only same-sex partners had lower odds of most HPV infection outcomes in multivariate analyses (p<0.05). Conclusions HPV infection is common among sexual minority women, though estimates vary depending on how sexual orientation is operationalised. Results can help inform targeted HPV and cervical cancer prevention efforts for sexual minority women. PMID:27165699

Effects of unplanned treatment interruptions on HIV treatment failure– results from TAHOD

PubMed Central

Jiamsakul, Awachana; Kerr, Stephen J.; Ng, Oon Tek; Lee, Man Po; Chaiwarith, Romanee; Yunihastuti, Evy; Van Nguyen, Kinh; Pham, Thuy Thanh; Kiertiburanakul, Sasisopin; Ditangco, Rossana; Saphonn, Vonthanak; Sim, Benedict L. H.; Merati, Tuti Parwati; Wong, Wingwai; Kantipong, Pacharee; Zhang, Fujie; Choi, Jun Yong; Pujari, Sanjay; Kamarulzaman, Adeeba; Oka, Shinichi; Mustafa, Mahiran; Ratanasuwan, Winai; Petersen, Boondarika; Law, Matthew; Kumarasamy, Nagalingeswaran

2016-01-01

Objectives Treatment interruptions (TI) of combination antiretroviral therapy (cART) are known to lead to unfavourable treatment outcomes but do still occur in resource-limited settings. We investigated the effects of TI associated with adverse events (AEs) and non-AE-related reasons, including their durations, on treatment failure after cART resumption in HIV-infected individuals in Asia. Methods Patients initiating cART between 2006-2013 were included. TI was defined as stopping cART for >1 day. Treatment failure was defined as confirmed virological, immunological or clinical failure. Time to treatment failure during cART was analysed using Cox regression, not including periods off treatment. Co-variables with p<0.10 in univariable analyses were included in multivariable analyses, where p<0.05 was considered statistically significant. Results Of 4549 patients from 13 countries in Asia, 3176 (69.8%) were male and the median age was 34 years. A total of 111 (2.4%) had TIs due to AEs and 135 (3.0%) had TIs for other reasons. Median interruption times were 22 days for AE and 148 days for non-AE TIs. In multivariable analyses, interruptions >30 days were associated with failure (31-180 days HR=2.66, 95%CI (1.70-4.16); 181-365 days HR=6.22, 95%CI (3.26-11.86); and >365 days HR=9.10, 95% CI (4.27-19.38), all p<0.001, compared to 0-14 days). Reasons for previous TI were not statistically significant (p=0.158). Conclusions Duration of interruptions of more than 30 days was the key factor associated with large increases in subsequent risk of treatment failure. If TI is unavoidable, its duration should be minimised to reduce the risk of failure after treatment resumption. PMID:26950901

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

A system to build distributed multivariate models and manage disparate data sharing policies: implementation in the scalable national network for effectiveness research.

PubMed

Meeker, Daniella; Jiang, Xiaoqian; Matheny, Michael E; Farcas, Claudiu; D'Arcy, Michel; Pearlman, Laura; Nookala, Lavanya; Day, Michele E; Kim, Katherine K; Kim, Hyeoneui; Boxwala, Aziz; El-Kareh, Robert; Kuo, Grace M; Resnic, Frederic S; Kesselman, Carl; Ohno-Machado, Lucila

2015-11-01

Centralized and federated models for sharing data in research networks currently exist. To build multivariate data analysis for centralized networks, transfer of patient-level data to a central computation resource is necessary. The authors implemented distributed multivariate models for federated networks in which patient-level data is kept at each site and data exchange policies are managed in a study-centric manner. The objective was to implement infrastructure that supports the functionality of some existing research networks (e.g., cohort discovery, workflow management, and estimation of multivariate analytic models on centralized data) while adding additional important new features, such as algorithms for distributed iterative multivariate models, a graphical interface for multivariate model specification, synchronous and asynchronous response to network queries, investigator-initiated studies, and study-based control of staff, protocols, and data sharing policies. Based on the requirements gathered from statisticians, administrators, and investigators from multiple institutions, the authors developed infrastructure and tools to support multisite comparative effectiveness studies using web services for multivariate statistical estimation in the SCANNER federated network. The authors implemented massively parallel (map-reduce) computation methods and a new policy management system to enable each study initiated by network participants to define the ways in which data may be processed, managed, queried, and shared. The authors illustrated the use of these systems among institutions with highly different policies and operating under different state laws. Federated research networks need not limit distributed query functionality to count queries, cohort discovery, or independently estimated analytic models. Multivariate analyses can be efficiently and securely conducted without patient-level data transport, allowing institutions with strict local data storage requirements to participate in sophisticated analyses based on federated research networks. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.

Panic disorder and agoraphobia: A direct comparison of their multivariate comorbidity patterns.

PubMed

Greene, Ashley L; Eaton, Nicholas R

2016-01-15

Scientific debate has long surrounded whether agoraphobia is a severe consequence of panic disorder or a frequently comorbid diagnosis. Multivariate comorbidity investigations typically treat these diagnoses as fungible in structural models, assuming both are manifestations of the fear-subfactor in the internalizing-externalizing model. No studies have directly compared these disorders' multivariate associations, which could clarify their conceptualization in classification and comorbidity research. In a nationally representative sample (N=43,093), we examined the multivariate comorbidity of panic disorder (1) without agoraphobia, (2) with agoraphobia, and (3) regardless of agoraphobia; and (4) agoraphobia without panic. We conducted exploratory and confirmatory factor analyses of these and 10 other lifetime DSM-IV diagnoses in a nationally representative sample (N=43,093). Differing bivariate and multivariate relations were found. Panic disorder without agoraphobia was largely a distress disorder, related to emotional disorders. Agoraphobia without panic was largely a fear disorder, related to phobias. When considered jointly, concomitant agoraphobia and panic was a fear disorder, and when panic was assessed without regard to agoraphobia (some individuals had agoraphobia while others did not) it was a mixed distress and fear disorder. Diagnoses were obtained from comprehensively trained lay interviewers, not clinicians and analyses used DSM-IV diagnoses (rather than DSM-5). These findings support the conceptualization of agoraphobia as a distinct diagnostic entity and the independent classification of both disorders in DSM-5, suggesting future multivariate comorbidity studies should not assume various panic/agoraphobia diagnoses are invariably fear disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Probabilistic flood damage modelling at the meso-scale

NASA Astrophysics Data System (ADS)

Kreibich, Heidi; Botto, Anna; Schröter, Kai; Merz, Bruno

2014-05-01

Decisions on flood risk management and adaptation are usually based on risk analyses. Such analyses are associated with significant uncertainty, even more if changes in risk due to global change are expected. Although uncertainty analysis and probabilistic approaches have received increased attention during the last years, they are still not standard practice for flood risk assessments. Most damage models have in common that complex damaging processes are described by simple, deterministic approaches like stage-damage functions. Novel probabilistic, multi-variate flood damage models have been developed and validated on the micro-scale using a data-mining approach, namely bagging decision trees (Merz et al. 2013). In this presentation we show how the model BT-FLEMO (Bagging decision Tree based Flood Loss Estimation MOdel) can be applied on the meso-scale, namely on the basis of ATKIS land-use units. The model is applied in 19 municipalities which were affected during the 2002 flood by the River Mulde in Saxony, Germany. The application of BT-FLEMO provides a probability distribution of estimated damage to residential buildings per municipality. Validation is undertaken on the one hand via a comparison with eight other damage models including stage-damage functions as well as multi-variate models. On the other hand the results are compared with official damage data provided by the Saxon Relief Bank (SAB). The results show, that uncertainties of damage estimation remain high. Thus, the significant advantage of this probabilistic flood loss estimation model BT-FLEMO is that it inherently provides quantitative information about the uncertainty of the prediction. Reference: Merz, B.; Kreibich, H.; Lall, U. (2013): Multi-variate flood damage assessment: a tree-based data-mining approach. NHESS, 13(1), 53-64.

Valuing the visual impact of wind farms: A calculus method for synthesizing choice experiments studies.

PubMed

Wen, Cheng; Dallimer, Martin; Carver, Steve; Ziv, Guy

2018-05-06

Despite the great potential of mitigating carbon emission, development of wind farms is often opposed by local communities due to the visual impact on landscape. A growing number of studies have applied nonmarket valuation methods like Choice Experiments (CE) to value the visual impact by eliciting respondents' willingness to pay (WTP) or willingness to accept (WTA) for hypothetical wind farms through survey questions. Several meta-analyses have been found in the literature to synthesize results from different valuation studies, but they have various limitations related to the use of the prevailing multivariate meta-regression analysis. In this paper, we propose a new meta-analysis method to establish general functions for the relationships between the estimated WTP or WTA and three wind farm attributes, namely the distance to residential/coastal areas, the number of turbines and turbine height. This method involves establishing WTA or WTP functions for individual studies, fitting the average derivative functions and deriving the general integral functions of WTP or WTA against wind farm attributes. Results indicate that respondents in different studies consistently showed increasing WTP for moving wind farms to greater distances, which can be fitted by non-linear (natural logarithm) functions. However, divergent preferences for the number of turbines and turbine height were found in different studies. We argue that the new analysis method proposed in this paper is an alternative to the mainstream multivariate meta-regression analysis for synthesizing CE studies and the general integral functions of WTP or WTA against wind farm attributes are useful for future spatial modelling and benefit transfer studies. We also suggest that future multivariate meta-analyses should include non-linear components in the regression functions. Copyright © 2018. Published by Elsevier B.V.

Clinical Trial Participation and Time to Treatment Among Adolescents and Young Adults With Cancer: Does Age at Diagnosis or Insurance Make a Difference?

PubMed Central

Parsons, Helen M.; Harlan, Linda C.; Seibel, Nita L.; Stevens, Jennifer L.; Keegan, Theresa H.M.

2011-01-01

Purpose Because adolescent and young adult (AYA) patients with cancer have experienced variable improvement in survival over the past two decades, enhancing the quality and timeliness of cancer care in this population has emerged as a priority area. To identify current trends in AYA care, we examined patterns of clinical trial participation, time to treatment, and provider characteristics in a population-based sample of AYA patients with cancer. Methods Using the National Cancer Institute Patterns of Care Study, we used multivariate logistic regression to evaluate demographic and provider characteristics associated with clinical trial enrollment and time to treatment among 1,358 AYA patients with cancer (age 15 to 39 years) identified through the Surveillance, Epidemiology, and End Results Program. Results In our study, 14% of patients age 15 to 39 years had enrolled onto a clinical trial; participation varied by type of cancer, with the highest participation in those diagnosed with acute lymphoblastic leukemia (37%) and sarcoma (32%). Multivariate analyses demonstrated that uninsured, older patients and those treated by nonpediatric oncologists were less likely to enroll onto clinical trials. Median time from pathologic confirmation to first treatment was 3 days, but this varied by race/ethnicity and cancer site. In multivariate analyses, advanced cancer stage and outpatient treatment alone were associated with longer time from pathologic confirmation to treatment. Conclusion Our study identified factors associated with low clinical trial participation in AYA patients with cancer. These findings support the continued need to improve access to clinical trials and innovative treatments for this population, which may ultimately translate into improved survival. PMID:21931022

Quality of life in Chronic Pancreatitis is determined by constant pain, disability/unemployment, current smoking and associated co-morbidities

PubMed Central

Machicado, Jorge D.; Amann, Stephen T; Anderson, Michelle A.; Abberbock, Judah; Sherman, Stuart; Conwell, Darwin; Cote, Gregory A.; Singh, Vikesh K.; Lewis, Michele; Alkaade, Samer; Sandhu, Bimaljit S.; Guda, Nalini M.; Muniraj, Thiruvengadam; Tang, Gong; Baillie, John; Brand, Randall; Gardner, Timothy B.; Gelrud, Andres; Forsmark, Christopher E.; Banks, Peter A.; Slivka, Adam; Wilcox, C. Mel; Whitcomb, David C.; Yadav, Dhiraj

2018-01-01

Background Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients. Methods We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype and treatments was obtained from responses to structured questionnaires. Physical (PCS) and mental (MCS) component summary scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. Results Mean PCS and MCS scores were 36.7±11.7 and 42.4±12.2, respectively. Significant (p<0.05) negative impact on PCS scores in multivariable analyses was noted due to constant mild-moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild-moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points) and medical co-morbidities. Significant (p<0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8-6.9 points), current smoking (3.9 points) and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional reduction 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. Conclusion Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses. PMID:28244497

Genetic Structure of Bluefin Tuna in the Mediterranean Sea Correlates with Environmental Variables

PubMed Central

Riccioni, Giulia; Stagioni, Marco; Landi, Monica; Ferrara, Giorgia; Barbujani, Guido; Tinti, Fausto

2013-01-01

Background Atlantic Bluefin Tuna (ABFT) shows complex demography and ecological variation in the Mediterranean Sea. Genetic surveys have detected significant, although weak, signals of population structuring; catch series analyses and tagging programs identified complex ABFT spatial dynamics and migration patterns. Here, we tested the hypothesis that the genetic structure of the ABFT in the Mediterranean is correlated with mean surface temperature and salinity. Methodology We used six samples collected from Western and Central Mediterranean integrated with a new sample collected from the recently identified easternmost reproductive area of Levantine Sea. To assess population structure in the Mediterranean we used a multidisciplinary framework combining classical population genetics, spatial and Bayesian clustering methods and a multivariate approach based on factor analysis. Conclusions FST analysis and Bayesian clustering methods detected several subpopulations in the Mediterranean, a result also supported by multivariate analyses. In addition, we identified significant correlations of genetic diversity with mean salinity and surface temperature values revealing that ABFT is genetically structured along two environmental gradients. These results suggest that a preference for some spawning habitat conditions could contribute to shape ABFT genetic structuring in the Mediterranean. However, further studies should be performed to assess to what extent ABFT spawning behaviour in the Mediterranean Sea can be affected by environmental variation. PMID:24260341

Exploratory multivariate modeling and prediction of the physico-chemical properties of surface water and groundwater

NASA Astrophysics Data System (ADS)

Ayoko, Godwin A.; Singh, Kirpal; Balerea, Steven; Kokot, Serge

2007-03-01

SummaryPhysico-chemical properties of surface water and groundwater samples from some developing countries have been subjected to multivariate analyses by the non-parametric multi-criteria decision-making methods, PROMETHEE and GAIA. Complete ranking information necessary to select one source of water in preference to all others was obtained, and this enabled relationships between the physico-chemical properties and water quality to be assessed. Thus, the ranking of the quality of the water bodies was found to be strongly dependent on the total dissolved solid, phosphate, sulfate, ammonia-nitrogen, calcium, iron, chloride, magnesium, zinc, nitrate and fluoride contents of the waters. However, potassium, manganese and zinc composition showed the least influence in differentiating the water bodies. To model and predict the water quality influencing parameters, partial least squares analyses were carried out on a matrix made up of the results of water quality assessment studies carried out in Nigeria, Papua New Guinea, Egypt, Thailand and India/Pakistan. The results showed that the total dissolved solid, calcium, sulfate, sodium and chloride contents can be used to predict a wide range of physico-chemical characteristics of water. The potential implications of these observations on the financial and opportunity costs associated with elaborate water quality monitoring are discussed.

Dermatoglyphic analysis of La Liébana (Cantabria, Spain). 2. Finger ridge counts.

PubMed

Martín, J; Gómez, P

1993-06-01

The results of univariate and multivariate analyses of the quantitative finger dermatoglyphic traits (i.e. ridge counts) of a sample of 109 males and 88 females from La Liébana (Cantabria, Spain) are reported. Univariate results follow the trends usually found in previous studies, e.g., ranking of finger ridge counts, bilateral asymmetry or shape of the distributions of the frequencies. However, sexual dimorphism is nearly inexistent concerning finger ridge counts. This lack of dimorphism could be related to certain characteristics of the distribution of finger dermatoglyphic patterns previously reported by the same authors. The multivariate description has been carried out by means of principal component analysis (with varimax rotation to obtain the final solution) of the correlation matrices computed from the 10 maximal finger ridge counts. Although the results do not necessarily prove the concept of developmental fields ("field theory" and later modifications), some precepts of the theory are present: field polarization and field overlapping.

Integration of vessel traits, wood density, and height in angiosperm shrubs and trees.

PubMed

Martínez-Cabrera, Hugo I; Schenk, H Jochen; Cevallos-Ferriz, Sergio R S; Jones, Cynthia S

2011-05-01

Trees and shrubs tend to occupy different niches within and across ecosystems; therefore, traits related to their resource use and life history are expected to differ. Here we analyzed how growth form is related to variation in integration among vessel traits, wood density, and height. We also considered the ecological and evolutionary consequences of such differences. In a sample of 200 woody plant species (65 shrubs and 135 trees) from Argentina, Mexico, and the United States, standardized major axis (SMA) regression, correlation analyses, and ANOVA were used to determine whether relationships among traits differed between growth forms. The influence of phylogenetic relationships was examined with a phylogenetic ANOVA and phylogenetically independent contrasts (PICs). A principal component analysis was conducted to determine whether trees and shrubs occupy different portions of multivariate trait space. Wood density did not differ between shrubs and trees, but there were significant differences in vessel diameter, vessel density, theoretical conductivity, and as expected, height. In addition, relationships between vessel traits and wood density differed between growth forms. Trees showed coordination among vessel traits, wood density, and height, but in shrubs, wood density and vessel traits were independent. These results hold when phylogenetic relationships were considered. In the multivariate analyses, these differences translated as significantly different positions in multivariate trait space occupied by shrubs and trees. Differences in trait integration between growth forms suggest that evolution of growth form in some lineages might be associated with the degree of trait interrelation.

A statistical framework for neuroimaging data analysis based on mutual information estimated via a gaussian copula

PubMed Central

Giordano, Bruno L.; Kayser, Christoph; Rousselet, Guillaume A.; Gross, Joachim; Schyns, Philippe G.

2016-01-01

Abstract We begin by reviewing the statistical framework of information theory as applicable to neuroimaging data analysis. A major factor hindering wider adoption of this framework in neuroimaging is the difficulty of estimating information theoretic quantities in practice. We present a novel estimation technique that combines the statistical theory of copulas with the closed form solution for the entropy of Gaussian variables. This results in a general, computationally efficient, flexible, and robust multivariate statistical framework that provides effect sizes on a common meaningful scale, allows for unified treatment of discrete, continuous, unidimensional and multidimensional variables, and enables direct comparisons of representations from behavioral and brain responses across any recording modality. We validate the use of this estimate as a statistical test within a neuroimaging context, considering both discrete stimulus classes and continuous stimulus features. We also present examples of analyses facilitated by these developments, including application of multivariate analyses to MEG planar magnetic field gradients, and pairwise temporal interactions in evoked EEG responses. We show the benefit of considering the instantaneous temporal derivative together with the raw values of M/EEG signals as a multivariate response, how we can separately quantify modulations of amplitude and direction for vector quantities, and how we can measure the emergence of novel information over time in evoked responses. Open‐source Matlab and Python code implementing the new methods accompanies this article. Hum Brain Mapp 38:1541–1573, 2017. © 2016 Wiley Periodicals, Inc. PMID:27860095

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

A Comparison of Anthropometric and Training Characteristics between Female and Male Half-Marathoners and the Relationship to Race Time

PubMed Central

Friedrich, Miriam; Rüst, Christoph A.; Rosemann, Thomas; Knechtle, Patrizia; Barandun, Ursula; Lepers, Romuald; Knechtle, Beat

2013-01-01

Purpose Lower limb skin-fold thicknesses have been differentially associated with sex in elite runners. Front thigh and medial calf skin-fold appear to be related to 1,500m and 10,000m time in men but 400m time in women. The aim of the present study was to compare anthropometric and training characteristics in recreational female and male half-marathoners. Methods The association between both anthropometry and training characteristics and race time was investigated in 83 female and 147 male recreational half marathoners using bi- and multi-variate analyses. Results In men, body fat percentage (β=0.6), running speed during training (β=-3.7), and body mass index (β=1.9) were related to half-marathon race time after multi-variate analysis. After exclusion of body mass index, r2 decreased from 0.51 to 0.49, but body fat percentage (β=0.8) and running speed during training (β=-4.1) remained predictive. In women, body fat percentage (β=0.75) and speed during training (β=-6.5) were related to race time (r2=0.73). For women, the exclusion of body mass index had no consequence on the predictive variables for half-marathon race time. Conclusion To summarize, in both female and male recreational half-marathoners, both body fat percentage and running speed during training sessions were related to half-marathon race times when corrected with co-variates after multi-variate regression analyses. PMID:24868427

Evoked prior learning experience and approach to learning as predictors of academic achievement.

PubMed

Trigwell, Keith; Ashwin, Paul; Millan, Elena S

2013-09-01

In separate studies and research from different perspectives, five factors are found to be among those related to higher quality outcomes of student learning (academic achievement). Those factors are higher self-efficacy, deeper approaches to learning, higher quality teaching, students' perceptions that their workload is appropriate, and greater learning motivation. University learning improvement strategies have been built on these research results. To investigate how students' evoked prior experience, perceptions of their learning environment, and their approaches to learning collectively contribute to academic achievement. This is the first study to investigate motivation and self-efficacy in the same educational context as conceptions of learning, approaches to learning and perceptions of the learning environment. Undergraduate students (773) from the full range of disciplines were part of a group of over 2,300 students who volunteered to complete a survey of their learning experience. On completing their degrees 6 and 18 months later, their academic achievement was matched with their learning experience survey data. A 77-item questionnaire was used to gather students' self-report of their evoked prior experience (self-efficacy, learning motivation, and conceptions of learning), perceptions of learning context (teaching quality and appropriate workload), and approaches to learning (deep and surface). Academic achievement was measured using the English honours degree classification system. Analyses were conducted using correlational and multi-variable (structural equation modelling) methods. The results from the correlation methods confirmed those found in numerous earlier studies. The results from the multi-variable analyses indicated that surface approach to learning was the strongest predictor of academic achievement, with self-efficacy and motivation also found to be directly related. In contrast to the correlation results, a deep approach to learning was not related to academic achievement, and teaching quality and conceptions of learning were only indirectly related to achievement. Research aimed at understanding how students experience their learning environment and how that experience relates to the quality of their learning needs to be conducted using a wider range of variables and more sophisticated analytical methods. In this study of one context, some of the relations found in earlier bivariate studies, and on which learning intervention strategies have been built, are not confirmed when more holistic teaching-learning contexts are analysed using multi-variable methods. © 2012 The British Psychological Society.

The influence of study design and sex-differences on results from developmental neurotoxicity studies of bisphenol A: implications for toxicity testing.

PubMed

Beronius, Anna; Johansson, Niklas; Rudén, Christina; Hanberg, Annika

2013-09-06

Developmental neurotoxicity (DNT) of bisphenol A (BPA) has been investigated in a large number of studies. However, there are discrepancies in the results reported between the studies. The aim of this study was to identify and analyze factors that may contribute to these differences and to assess whether there are sex-differences in the sensitivity of certain endpoints or tests used in DNT-studies. Forty-four DNT studies of BPA were identified from the open literature. Details about study design and results from each study, as well as the criteria for DNT testing according to the standardized OECD test guideline (TG) 426, were collected in a database. This enabled systematic and detailed comparisons between studies as well as to the criteria and recommendations stated in TG 426. Multivariate analyses were also used to investigate how different factors of the study design contributed to differences in study results. The analyses showed behavioral effects were often observed for endpoints that are not required according to OECD TG 426, such as anxiety-related, social and sexual behaviors, especially at very low doses and in female offspring. On the other hand relatively few studies observed any effects on motor activity, which is commonly used in screening for neurotoxic effects in regulatory testing. However, varied and to some extent seemingly contradictory results have been reported in these studies, especially for endpoints related to motor activity and anxiety and exploration. Many studies were also poorly reported, limiting these analyses. No strong conclusions could be drawn from the multivariate analyses. A few factors of study design, such as the size of the dose and number of dose levels used and the use of litter or individual pup as statistical unit seemed to have some influence on study results. In conclusion, this analysis suggests that DNT-studies conducted according to the standardized OECD TG 426 may overlook sensitive effects of BPA, and possibly other potential endocrine disruptors, especially in female offspring. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Modeling the Drift Towards Sex Role Deviance.

ERIC Educational Resources Information Center

James, Jennifer; Vitaliano, Peter Paul

The interrelationships of deviant life experiences and current status, i.e., prostitution versus non-prostitution, were investigated by the application of multivariate analyses. Variables were studied involving early home life, pregnancy history, sexual history, and criminal involvement. Based on the analyses, three models were developed that…

Synergism in work site adoption of employee assistance programs and health promotion activities.

PubMed

Blum, T C; Roman, P M; Patrick, L

1990-05-01

As workplaces increasingly adopt proactive programs directed toward employee health issues, the interrelation between different programs becomes an important issue. Of interest here is the "synergy" in patterns of program adoption between employee assistance programs (EAPs) and health promotion activities (HPAs). We utilize the 1985 National Survey of Worksite Health Promotion Activities (N = 1358) for analyses of the dual presence of EAPs and HPAs, and in multivariate analyses we consider factors affecting such dual presence. The data suggest that synergy occurs, with EAP adoption appearing to influence HPA adoption to a greater extent than the reverse. In multivariate analyses, synergy is confirmed by the finding that, among a variety of relevant organizational characteristics, EAP presence and HPA presence are the best predictors of each other's presence. The analyses also indicate that there is minimal commonality in program ingredients across organizations reporting the presence of HPAs. Implications of the data for the future development of these two programming strategies are discussed.

Processes and subdivisions in diogenites, a multivariate statistical analysis

NASA Technical Reports Server (NTRS)

Harriott, T. A.; Hewins, R. H.

1984-01-01

Multivariate statistical techniques used on diogenite orthopyroxene analyses show the relationships that occur within diogenites and the two orthopyroxenite components (class I and II) in the polymict diogenite Garland. Cluster analysis shows that only Peckelsheim is similar to Garland class I (Fe-rich) and the other diogenites resemble Garland class II. The unique diogenite Y 75032 may be related to type I by fractionation. Factor analysis confirms the subdivision and shows that Fe does not correlate with the weakly incompatible elements across the entire pyroxene composition range, indicating that igneous fractionation is not the process controlling total diogenite composition variation. The occurrence of two groups of diogenites is interpreted as the result of sampling or mixing of two main sequences of orthopyroxene cumulates with slightly different compositions.

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.

Patient experience and process measures of quality of care at home health agencies: Factors associated with high performance.

PubMed

Smith, Laura M; Anderson, Wayne L; Lines, Lisa M; Pronier, Cristalle; Thornburg, Vanessa; Butler, Janelle P; Teichman, Lori; Dean-Whittaker, Debra; Goldstein, Elizabeth

2017-01-01

We examined the effects of provider characteristics on home health agency performance on patient experience of care (Home Health CAHPS) and process (OASIS) measures. Descriptive, multivariate, and factor analyses were used. While agencies score high on both domains, factor analyses showed that the underlying items represent separate constructs. Freestanding and Visiting Nurse Association agencies, higher number of home health aides per 100 episodes, and urban location were statistically significant predictors of lower performance. Lack of variation in composite measures potentially led to counterintuitive results for effects of organizational characteristics. This exploratory study showed the value of having separate quality domains.

Regression and multivariate models for predicting particulate matter concentration level.

PubMed

Nazif, Amina; Mohammed, Nurul Izma; Malakahmad, Amirhossein; Abualqumboz, Motasem S

2018-01-01

The devastating health effects of particulate matter (PM 10 ) exposure by susceptible populace has made it necessary to evaluate PM 10 pollution. Meteorological parameters and seasonal variation increases PM 10 concentration levels, especially in areas that have multiple anthropogenic activities. Hence, stepwise regression (SR), multiple linear regression (MLR) and principal component regression (PCR) analyses were used to analyse daily average PM 10 concentration levels. The analyses were carried out using daily average PM 10 concentration, temperature, humidity, wind speed and wind direction data from 2006 to 2010. The data was from an industrial air quality monitoring station in Malaysia. The SR analysis established that meteorological parameters had less influence on PM 10 concentration levels having coefficient of determination (R 2 ) result from 23 to 29% based on seasoned and unseasoned analysis. While, the result of the prediction analysis showed that PCR models had a better R 2 result than MLR methods. The results for the analyses based on both seasoned and unseasoned data established that MLR models had R 2 result from 0.50 to 0.60. While, PCR models had R 2 result from 0.66 to 0.89. In addition, the validation analysis using 2016 data also recognised that the PCR model outperformed the MLR model, with the PCR model for the seasoned analysis having the best result. These analyses will aid in achieving sustainable air quality management strategies.

Immediate versus delayed intramedullary nailing for open fractures of the tibial shaft: a multivariate analysis of factors affecting deep infection and fracture healing.

PubMed

Yokoyama, Kazuhiko; Itoman, Moritoshi; Uchino, Masataka; Fukushima, Kensuke; Nitta, Hiroshi; Kojima, Yoshiaki

2008-10-01

The purpose of this study was to evaluate contributing factors affecting deep infection and fracture healing of open tibia fractures treated with locked intramedullary nailing (IMN) by multivariate analysis. We examined 99 open tibial fractures (98 patients) treated with immediate or delayed locked IMN in static fashion from 1991 to 2002. Multivariate analyses following univariate analyses were derived to determine predictors of deep infection, nonunion, and healing time to union. The following predictive variables of deep infection were selected for analysis: age, sex, Gustilo type, fracture grade by AO type, fracture location, timing or method of IMN, reamed or unreamed nailing, debridement time (< or =6 h or >6 h), method of soft-tissue management, skin closure time (< or =1 week or >1 week), existence of polytrauma (ISS< 18 or ISS> or =18), existence of floating knee injury, and existence of superficial/pin site infection. The predictive variables of nonunion selected for analysis was the same as those for deep infection, with the addition of deep infection for exchange of pin site infection. The predictive variables of union time selected for analysis was the same as those for nonunion, excluding of location, debridement time, and existence of floating knee and superficial infection. Six (6.1%; type II Gustilo n=1, type IIIB Gustilo n=5) of the 99 open tibial fractures developed deep infections. Multivariate analysis revealed that timing or method of IMN, debridement time, method of soft-tissue management, and existence of superficial or pin site infection significantly correlated with the occurrence of deep infection (P< 0.0001). In the immediate nailing group alone, the deep infection rate in type IIIB + IIIC was significantly higher than those in type I + II and IIIA (P = 0.016). Nonunion occurred in 17 fractures (20.3%, 17/84). Multivariate analysis revealed that Gustilo type, skin closure time, and existence of deep infection significantly correlated with occurrence of nonunion (P < 0.05). Gustilo type and existence of deep infection were significantly correlated with healing time to union on multivariate analysis (r(2) = 0.263, P = 0.0001). Multivariate analyses for open tibial fractures treated with IMN showed that IMN after EF (especially in existence of pin site infection) was at high risk of deep infection, and that debridement within 6 h and appropriate soft-tissue managements were also important factor in preventing deep infections. These analyses postulated that both the Gustilo type and the existence of deep infection is related with fracture healing in open fractures treated with IMN. In addition, immediate IMN for type IIIB and IIIC is potentially risky, and canal reaming did not increase the risk of complication for open tibial fractures treated with IMN.

Multivariate Quantitative Chemical Analysis

NASA Technical Reports Server (NTRS)

Kinchen, David G.; Capezza, Mary

1995-01-01

Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

Causal diagrams and multivariate analysis III: confound it!

PubMed

Jupiter, Daniel C

2015-01-01

This commentary concludes my series concerning inclusion of variables in multivariate analyses. We take up the issues of confounding and effect modification and summarize the work we have thus far done. Finally, we provide a rough algorithm to help guide us through the maze of possibilities that we have outlined. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

EVENT-LEVEL ANALYSIS OF ANAL SEX ROLES AND SEX DRUG USE AMONG GAY AND BISEXUAL MEN IN VANCOUVER, BRITISH COLUMBIA, CANADA

PubMed Central

Rich, Ashleigh J; Lachowsky, Nathan J; Cui, Zishan; Sereda, Paul; Lal, Allan; Moore, David M; Hogg, Robert S; Roth, Eric A

2015-01-01

This study analyzed event-level partnership data from a computer-assisted survey of 719 gay and bisexual men (GBM) enrolled in the Momentum Health Study to delineate potential linkages between anal sex roles and so-called “sex drugs”, i.e. erectile dysfunction drugs (EDD), poppers and crystal methamphetamine. Univariable and multivariable analyses using generalized linear mixed models with logit link function with sexual encounters (n=2,514) as the unit of analysis tested four hypotheses: 1) EDD are significantly associated with insertive anal sex roles, 2) poppers are significantly associated with receptive anal sex, 3) both poppers and EDD are significantly associated with anal sexual versatility and, 4) crystal methamphetamine is significantly associated with all anal sex roles. Data for survey respondents and their sexual partners allowed testing these hypotheses for both anal sex partners in the same encounter. Multivariable results supported the first three hypotheses. Crystal methamphetamine was significantly associated with all anal sex roles in the univariable models, but not significant in any multivariable ones. Other multivariable significant variables included attending group sex events, venue where first met, and self-described sexual orientation. Results indicate that GBM sex-drug use behavior features rational decision-making strategies linked to anal sex roles. They also suggest that more research on anal sex roles, particularly versatility, is needed, and that sexual behavior research can benefit from partnership analysis. PMID:26525571

Event-Level Analysis of Anal Sex Roles and Sex Drug Use Among Gay and Bisexual Men in Vancouver, British Columbia, Canada.

PubMed

Rich, Ashleigh J; Lachowsky, Nathan J; Cui, Zishan; Sereda, Paul; Lal, Allan; Moore, David M; Hogg, Robert S; Roth, Eric A

2016-08-01

This study analyzed event-level partnership data from a computer-assisted survey of 719 gay and bisexual men (GBM) enrolled in the Momentum Health Study to delineate potential linkages between anal sex roles and the so-called "sex drugs," i.e., erectile dysfunction drugs (EDD), poppers, and crystal methamphetamine. Univariable and multivariable analyses using generalized linear mixed models with logit link function with sexual encounters (n = 2514) as the unit of analysis tested four hypotheses: (1) EDD are significantly associated with insertive anal sex roles, (2) poppers are significantly associated with receptive anal sex, (3) both poppers and EDD are significantly associated with anal sexual versatility, and (4) crystal methamphetamine is significantly associated with all anal sex roles. Data for survey respondents and their sexual partners allowed testing these hypotheses for both anal sex partners in the same encounter. Multivariable results supported the first three hypotheses. Crystal methamphetamine was significantly associated with all anal sex roles in the univariable models, but not significant in any multivariable ones. Other multivariable significant variables included attending group sex events, venue where first met, and self-described sexual orientation. Results indicate that GBM sex-drug use behavior features rational decision-making strategies linked to anal sex roles. They also suggest that more research on anal sex roles, particularly versatility, is needed, and that sexual behavior research can benefit from partnership analysis.

The relationship between physical appearance concerns, disgust, and anti-fat prejudice.

PubMed

O'Brien, Kerry S; Daníelsdóttir, Sigrún; Ólafsson, Ragnar P; Hansdóttir, Ingunn; Fridjónsdóttir, Thorarna G; Jónsdóttir, Halla

2013-09-01

This study examined relationships between physical appearance concerns (fear of fat, body image disturbance; BIDQ), disgust, and anti-fat prejudice (dislike, blame), and tested whether disgust mediates relationships between physical appearance concerns and anti-fat prejudice. Participants (N=1649; age=28 years) provided demographic data and completed measures of anti-fat prejudice, tendency to feel disgust, and physical appearance concerns. Univariate, multivariate, and mediation analyses were conducted. Univariate and multivariate associations were found between fear of fat, BIDQ, disgust, and anti-fat prejudice for women. For women only, mediation analyses showed that disgust partially mediated relationships between physical appearance concerns and dislike of fat people. For men, univariate and multivariate relationships were found between fear of fat, and dislike and blame of fat people, but disgust was not related to anti-fat prejudice. Newer constructs centering on physical appearance concerns and disgust appear promising candidates for understanding anti-fat prejudice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Partial Least Square Analyses of Landscape and Surface Water Biota Associations in the Savannah River Basin

EPA Science Inventory

Ecologists are often faced with problem of small sample size, correlated and large number of predictors, and high noise-to-signal relationships. This necessitates excluding important variables from the model when applying standard multiple or multivariate regression analyses. In ...

Matrix metalloproteinase-2 gene variants and abdominal aortic aneurysm.

PubMed

Smallwood, L; Warrington, N; Allcock, R; van Bockxmeer, F; Palmer, L J; Iacopetta, B; Golledge, J; Norman, P E

2009-08-01

To investigate associations between two polymorphisms of the matrix metalloproteinase-2 gene (MMP2) and the incidence and progression of abdominal aortic aneurysm (AAA). Cases and controls were recruited from a trial of screening for AAAs. The association between two variants of MMP2 (-1360C>T, and +649C>T) in men with AAA (n=678) and in controls (n=659) was examined using multivariate analyses. The association with AAA expansion (n=638) was also assessed. In multivariate analyses with adjustments for multiple testing, no association between either SNP and AAA presence or expansion was detected. MMP2 -1360C>T and +649C>T variants are not risk factors for AAA.

A Methodology for Conducting Integrative Mixed Methods Research and Data Analyses

PubMed Central

Castro, Felipe González; Kellison, Joshua G.; Boyd, Stephen J.; Kopak, Albert

2011-01-01

Mixed methods research has gained visibility within the last few years, although limitations persist regarding the scientific caliber of certain mixed methods research designs and methods. The need exists for rigorous mixed methods designs that integrate various data analytic procedures for a seamless transfer of evidence across qualitative and quantitative modalities. Such designs can offer the strength of confirmatory results drawn from quantitative multivariate analyses, along with “deep structure” explanatory descriptions as drawn from qualitative analyses. This article presents evidence generated from over a decade of pilot research in developing an integrative mixed methods methodology. It presents a conceptual framework and methodological and data analytic procedures for conducting mixed methods research studies, and it also presents illustrative examples from the authors' ongoing integrative mixed methods research studies. PMID:22167325

Relationship between central and peripheral atherosclerosis and left ventricular dysfunction in a community population.

PubMed

Tsao, Connie W; Gona, Philimon; Salton, Carol; Murabito, Joanne M; Oyama, Noriko; Danias, Peter G; O'Donnell, Christopher J; Manning, Warren J; Yeon, Susan B

2011-08-01

We aimed to determine the relationships between resting left ventricular (LV) wall motion abnormalities (WMAs), aortic plaque, and peripheral artery disease (PAD) in a community cohort. A total of 1726 Framingham Heart Study Offspring Cohort participants (806 males, 65 ± 9 years) underwent cardiovascular magnetic resonance with quantification of aortic plaque volume and assessment of regional left ventricular systolic function. Claudication, lower extremity revascularization, and ankle-brachial index (ABI) were recorded at the most contemporaneous examination visit. WMAs were associated with greater aortic plaque burden, decreased ABI, and claudication in age- and sex-adjusted analyses (all p < 0.001), which were not significant after adjustment for cardiovascular risk factors. In age- and sex-adjusted analyses, both the presence (p < 0.001) and volume of aortic plaque were associated with decreased ABI (p < 0.001). After multivariable adjustment, an ABI ≤ 0.9 or prior revascularization was associated with a threefold odds of aortic plaque (p = 0.0083). Plaque volume significantly increased with decreasing ABI in multivariable-adjusted analyses (p < 0.0001). In this free-living population, associations of WMAs with aortic plaque burden and clinical measures of PAD were attenuated after adjustment for coronary heart disease risk factors. Aortic plaque volume and ABI remained strongly negatively correlated after multivariable adjustment. Our findings suggest that the association between coronary heart disease and non-coronary atherosclerosis is explained by cardiovascular risk factors. Aortic atherosclerosis and PAD remain strongly associated after multivariable adjustment, suggesting shared mechanisms beyond those captured by traditional risk factors.

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.

Transmission clustering among newly diagnosed HIV patients in Chicago, 2008 to 2011: using phylogenetics to expand knowledge of regional HIV transmission patterns

PubMed Central

Lubelchek, Ronald J.; Hoehnen, Sarah C.; Hotton, Anna L.; Kincaid, Stacey L.; Barker, David E.; French, Audrey L.

2014-01-01

Introduction HIV transmission cluster analyses can inform HIV prevention efforts. We describe the first such assessment for transmission clustering among HIV patients in Chicago. Methods We performed transmission cluster analyses using HIV pol sequences from newly diagnosed patients presenting to Chicago’s largest HIV clinic between 2008 and 2011. We compared sequences via progressive pairwise alignment, using neighbor joining to construct an un-rooted phylogenetic tree. We defined clusters as >2 sequences among which each sequence had at least one partner within a genetic distance of ≤ 1.5%. We used multivariable regression to examine factors associated with clustering and used geospatial analysis to assess geographic proximity of phylogenetically clustered patients. Results We compared sequences from 920 patients; median age 35 years; 75% male; 67% Black, 23% Hispanic; 8% had a Rapid Plasma Reagin (RPR) titer ≥ 1:16 concurrent with their HIV diagnosis. We had HIV transmission risk data for 54%; 43% identified as men who have sex with men (MSM). Phylogenetic analysis demonstrated 123 patients (13%) grouped into 26 clusters, the largest having 20 members. In multivariable regression, age < 25, Black race, MSM status, male gender, higher HIV viral load, and RPR ≥ 1:16 associated with clustering. We did not observe geographic grouping of genetically clustered patients. Discussion Our results demonstrate high rates of HIV transmission clustering, without local geographic foci, among young Black MSM in Chicago. Applied prospectively, phylogenetic analyses could guide prevention efforts and help break the cycle of transmission. PMID:25321182

Body proportions of circumpolar peoples as evidenced from skeletal data: Ipiutak and Tigara (Point Hope) versus Kodiak Island Inuit.

PubMed

Holliday, Trenton W; Hilton, Charles E

2010-06-01

Given the well-documented fact that human body proportions covary with climate (presumably due to the action of selection), one would expect that the Ipiutak and Tigara Inuit samples from Point Hope, Alaska, would be characterized by an extremely cold-adapted body shape. Comparison of the Point Hope Inuit samples to a large (n > 900) sample of European and European-derived, African and African-derived, and Native American skeletons (including Koniag Inuit from Kodiak Island, Alaska) confirms that the Point Hope Inuit evince a cold-adapted body form, but analyses also reveal some unexpected results. For example, one might suspect that the Point Hope samples would show a more cold-adapted body form than the Koniag, given their more extreme environment, but this is not the case. Additionally, univariate analyses seldom show the Inuit samples to be more cold-adapted in body shape than Europeans, and multivariate cluster analyses that include a myriad of body shape variables such as femoral head diameter, bi-iliac breadth, and limb segment lengths fail to effectively separate the Inuit samples from Europeans. In fact, in terms of body shape, the European and the Inuit samples tend to be cold-adapted and tend to be separated in multivariate space from the more tropically adapted Africans, especially those groups from south of the Sahara. Copyright 2009 Wiley-Liss, Inc.

[The impact of stress and personality on resilience of patients with ulcerative colitis].

PubMed

Liu, W; Wang, J; Wang, H; Chen, X Y; Li, J S

2018-02-01

Objective: To study relevant factors that influence psychological resilience in patients with ulcerative colitis(UC), especially the role of perceived stress and personality. Methods: Patients with UC were recruited from January 2015 to December 2016 in the First Hospital of Zhengzhou University. Education levels, income, duration of disease, Mayo score and disease phenotype according to Montreal classification were collected. Resilience was measured using Connor-Davidson resilience scale (CD-RISC). Perceived stress was measured by perceived stress scale (PSS). Personality was evaluated using Eysenck personality questionnaire (EPQ). Univariate analyses were conducted to determine the correlation of variables with resilience and thereafter those statistically significant were reanalyzed via a multivariate regression model. Results: A total of 188 patients with UC were finally recruited. Univariate analyses demonstrated resilience was inversely associated with perceived stress, Mayo score and neuroticism. Extraversion, income, college education were positively related to resilience. However, multivariate analyses revealed that perceived stress( OR= 0.901, 95% CI 0.833-0.975), extraversion ( OR= 1.257, 95% CI 1.087-1.454), neuroticism ( OR= 0.818, 95% CI 0.679-0.985), Mayo score ( OR= 0.856, 95% CI 0.742-0.988) and income ( OR= 6.411, 95% CI 2.136-9.244) were significantly related to resilience. Conclusions: Resilience of UC patients is not only associated with disease activity, but also with personality, perceived stress and income.

Comparison of Muscle Mass Indices Using Computed Tomography or Dual X-Ray Absorptiometry for Predicting Physical Performance in Hemodialysis Patients.

PubMed

Kang, Seok Hui; Lee, Hyun Seok; Lee, Sukyung; Cho, Ji-Hyung; Kim, Jun Chul

2017-01-01

Our study aims to evaluate the association between thigh muscle cross-sectional area (TMA) using computed tomography (CT), or appendicular skeletal muscle mass (ASM) using dual energy X-ray absorptiometry (DEXA), and physical performance levels in hemodialysis (HD) patients. Patients were included if they were on HD for ≥6 months (n = 84). ASM and TMA were adjusted to body weight (BW, kg) or height2 (Ht2, m2). Each participant performed a short physical performance battery test (SPPB), a sit-to-stand for 30 second test (STS30), a 6-minute walk test (6-MWT), a timed up and go test (TUG), and hand grip strength (HGS) test. Correlation coefficients for SPPB, GS, 5STS, STS30, 6-MWT, and TUG were highest in TMA/BW. Results from partial correlation or linear regression analyses displayed similar trends to those derived from Pearson's correlation analyses. An increase in TMA/BW or TMA/Ht2 was associated with a decreased odds ratio of low SPPB, GS, or HGS in multivariate analyses. Indices using DEXA were associated with a decreased odds ratio of a low HGS only in multivariate analysis. TMA indices using CT may be more valuable in predicting physical performance or strength in HD patients. © 2017 The Author(s). Published by S. Karger AG, Basel.

Do state characteristics matter? State level factors related to tobacco cessation quitlines

PubMed Central

Keller, Paula A; Koss, Kalsea J; Baker, Timothy B; Bailey, Linda A; Fiore, Michael C

2007-01-01

Background Quitline services are an effective population‐wide tobacco cessation strategy adopted widely in the United States as part of state comprehensive tobacco control efforts. Despite widespread evidence supporting quitlines' effectiveness, many states lack sufficient financial resources to adequately fund and promote this service. Efforts to augment state tobacco control efforts might be fostered by greater knowledge of state level factors associated with the funding and implementation of those efforts. Methods We analysed data from the 2004 North American Quitline Consortium survey and from publicly available sources to identify state level factors related to quitline implementation and funding. Factors included in the analyses were state demographic characteristics, tobacco use variables, state tobacco control spending, and economic and political climate variables. Univariate and multivariate regression analyses were conducted. Results The best fitting multivariate model that significantly predicted the presence or absence of a state quitline included only cigarette excise tax rate (p = 0.020). In terms of funding levels, states with high rates of cigarette consumption (p = 0.047) and with higher per capita expenditures for tobacco control programmes (p = 0 .0.004) were most likely to spend more on per capita operations budget for quitlines. Conclusion State level factors appear to play a part in whether states had established quitlines by mid‐2004 and the amount of per capita quitline funding. PMID:18048637

Network meta-analysis of multiple outcome measures accounting for borrowing of information across outcomes.

PubMed

Achana, Felix A; Cooper, Nicola J; Bujkiewicz, Sylwia; Hubbard, Stephanie J; Kendrick, Denise; Jones, David R; Sutton, Alex J

2014-07-21

Network meta-analysis (NMA) enables simultaneous comparison of multiple treatments while preserving randomisation. When summarising evidence to inform an economic evaluation, it is important that the analysis accurately reflects the dependency structure within the data, as correlations between outcomes may have implication for estimating the net benefit associated with treatment. A multivariate NMA offers a framework for evaluating multiple treatments across multiple outcome measures while accounting for the correlation structure between outcomes. The standard NMA model is extended to multiple outcome settings in two stages. In the first stage, information is borrowed across outcomes as well across studies through modelling the within-study and between-study correlation structure. In the second stage, we make use of the additional assumption that intervention effects are exchangeable between outcomes to predict effect estimates for all outcomes, including effect estimates on outcomes where evidence is either sparse or the treatment had not been considered by any one of the studies included in the analysis. We apply the methods to binary outcome data from a systematic review evaluating the effectiveness of nine home safety interventions on uptake of three poisoning prevention practices (safe storage of medicines, safe storage of other household products, and possession of poison centre control telephone number) in households with children. Analyses are conducted in WinBUGS using Markov Chain Monte Carlo (MCMC) simulations. Univariate and the first stage multivariate models produced broadly similar point estimates of intervention effects but the uncertainty around the multivariate estimates varied depending on the prior distribution specified for the between-study covariance structure. The second stage multivariate analyses produced more precise effect estimates while enabling intervention effects to be predicted for all outcomes, including intervention effects on outcomes not directly considered by the studies included in the analysis. Accounting for the dependency between outcomes in a multivariate meta-analysis may or may not improve the precision of effect estimates from a network meta-analysis compared to analysing each outcome separately.

Family-Based Rare Variant Association Analysis: A Fast and Efficient Method of Multivariate Phenotype Association Analysis.

PubMed

Wang, Longfei; Lee, Sungyoung; Gim, Jungsoo; Qiao, Dandi; Cho, Michael; Elston, Robert C; Silverman, Edwin K; Won, Sungho

2016-09-01

Family-based designs have been repeatedly shown to be powerful in detecting the significant rare variants associated with human diseases. Furthermore, human diseases are often defined by the outcomes of multiple phenotypes, and thus we expect multivariate family-based analyses may be very efficient in detecting associations with rare variants. However, few statistical methods implementing this strategy have been developed for family-based designs. In this report, we describe one such implementation: the multivariate family-based rare variant association tool (mFARVAT). mFARVAT is a quasi-likelihood-based score test for rare variant association analysis with multiple phenotypes, and tests both homogeneous and heterogeneous effects of each variant on multiple phenotypes. Simulation results show that the proposed method is generally robust and efficient for various disease models, and we identify some promising candidate genes associated with chronic obstructive pulmonary disease. The software of mFARVAT is freely available at http://healthstat.snu.ac.kr/software/mfarvat/, implemented in C++ and supported on Linux and MS Windows. © 2016 WILEY PERIODICALS, INC.

Remote sensing and GIS-based landslide hazard analysis and cross-validation using multivariate logistic regression model on three test areas in Malaysia

NASA Astrophysics Data System (ADS)

Pradhan, Biswajeet

2010-05-01

This paper presents the results of the cross-validation of a multivariate logistic regression model using remote sensing data and GIS for landslide hazard analysis on the Penang, Cameron, and Selangor areas in Malaysia. Landslide locations in the study areas were identified by interpreting aerial photographs and satellite images, supported by field surveys. SPOT 5 and Landsat TM satellite imagery were used to map landcover and vegetation index, respectively. Maps of topography, soil type, lineaments and land cover were constructed from the spatial datasets. Ten factors which influence landslide occurrence, i.e., slope, aspect, curvature, distance from drainage, lithology, distance from lineaments, soil type, landcover, rainfall precipitation, and normalized difference vegetation index (ndvi), were extracted from the spatial database and the logistic regression coefficient of each factor was computed. Then the landslide hazard was analysed using the multivariate logistic regression coefficients derived not only from the data for the respective area but also using the logistic regression coefficients calculated from each of the other two areas (nine hazard maps in all) as a cross-validation of the model. For verification of the model, the results of the analyses were then compared with the field-verified landslide locations. Among the three cases of the application of logistic regression coefficient in the same study area, the case of Selangor based on the Selangor logistic regression coefficients showed the highest accuracy (94%), where as Penang based on the Penang coefficients showed the lowest accuracy (86%). Similarly, among the six cases from the cross application of logistic regression coefficient in other two areas, the case of Selangor based on logistic coefficient of Cameron showed highest (90%) prediction accuracy where as the case of Penang based on the Selangor logistic regression coefficients showed the lowest accuracy (79%). Qualitatively, the cross application model yields reasonable results which can be used for preliminary landslide hazard mapping.

Transition from a multiport technique to a single-port technique for lung cancer surgery: is lymph node dissection inferior using the single-port technique?†.

PubMed

Liu, Chia-Chuan; Shih, Chih-Shiun; Pennarun, Nicolas; Cheng, Chih-Tao

2016-01-01

The feasibility and radicalism of lymph node dissection for lung cancer surgery by a single-port technique has frequently been challenged. We performed a retrospective cohort study to investigate this issue. Two chest surgeons initiated multiple-port thoracoscopic surgery in a 180-bed cancer centre in 2005 and shifted to a single-port technique gradually after 2010. Data, including demographic and clinical information, from 389 patients receiving multiport thoracoscopic lobectomy or segmentectomy and 149 consecutive patients undergoing either single-port lobectomy or segmentectomy for primary non-small-cell lung cancer were retrieved and entered for statistical analysis by multivariable linear regression models and Box-Cox transformed multivariable analysis. The mean number of total dissected lymph nodes in the lobectomy group was 28.5 ± 11.7 for the single-port group versus 25.2 ± 11.3 for the multiport group; the mean number of total dissected lymph nodes in the segmentectomy group was 19.5 ± 10.8 for the single-port group versus 17.9 ± 10.3 for the multiport group. In linear multivariable and after Box-Cox transformed multivariable analyses, the single-port approach was still associated with a higher total number of dissected lymph nodes. The total number of dissected lymph nodes for primary lung cancer surgery by single-port video-assisted thoracoscopic surgery (VATS) was higher than by multiport VATS in univariable, multivariable linear regression and Box-Cox transformed multivariable analyses. This study confirmed that highly effective lymph node dissection could be achieved through single-port VATS in our setting. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

A stochastic storm surge generator for the German North Sea and the multivariate statistical assessment of the simulation results

NASA Astrophysics Data System (ADS)

Wahl, Thomas; Jensen, Jürgen; Mudersbach, Christoph

2010-05-01

Storm surges along the German North Sea coastline led to major damages in the past and the risk of inundation is expected to increase in the course of an ongoing climate change. The knowledge of the characteristics of possible storm surges is essential for the performance of integrated risk analyses, e.g. based on the source-pathway-receptor concept. The latter includes the storm surge simulation/analyses (source), modelling of dike/dune breach scenarios (pathway) and the quantification of potential losses (receptor). In subproject 1b of the German joint research project XtremRisK (www.xtremrisk.de), a stochastic storm surge generator for the south-eastern North Sea area is developed. The input data for the multivariate model are high resolution sea level observations from tide gauges during extreme events. Based on 25 parameters (19 sea level parameters and 6 time parameters) observed storm surge hydrographs consisting of three tides are parameterised. Followed by the adaption of common parametric probability distributions and a large number of Monte-Carlo-Simulations, the final reconstruction leads to a set of 100.000 (default) synthetic storm surge events with a one-minute resolution. Such a data set can potentially serve as the basis for a large number of applications. For risk analyses, storm surges with peak water levels exceeding the design water levels are of special interest. The occurrence probabilities of the simulated extreme events are estimated based on multivariate statistics, considering the parameters "peak water level" and "fullness/intensity". In the past, most studies considered only the peak water levels during extreme events, which might not be the most important parameter in any cases. Here, a 2D-Archimedian copula model is used for the estimation of the joint probabilities of the selected parameters, accounting for the structures of dependence overlooking the margins. In coordination with subproject 1a, the results will be used as the input for the XtremRisK subprojects 2 to 4. The project is funded by the German Federal Ministry of Education and Research (BMBF) (Project No. 03 F 0483 B).

Lymphopenia Association With Gross Tumor Volume and Lung V5 and Its Effects on Non-Small Cell Lung Cancer Patient Outcomes

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

Tang, Chad; Liao, Zhongxing, E-mail: zliao@mdanderson.org; Gomez, Daniel

2014-08-01

Purpose: Radiation therapy (RT) can both suppress and stimulate the immune system. We sought to investigate the mechanisms underlying radiation-induced lymphopenia and its associations with patient outcomes in non-small cell lung cancer (NSCLC). Methods and Materials: Subjects consisted of 711 patients who had received definitive RT for NSCLC. A lymphocyte nadir was calculated as the minimum lymphocyte value measured during definitive RT. Associations between gross tumor volumes (GTVs) and lung dose-volume histogram (DVH) parameters with lymphocyte nadirs were assessed with Spearman correlation coefficients. Relationships between lymphocyte nadirs with overall survival (OS) and event free survival (EFS) were evaluated with Kaplan-Meiermore » analysis and compared with log-rank test results. Multivariate regressions were conducted with linear and Cox regression analyses. All variables were analyzed as continuous if possible. Results: Larger GTVs were correlated with lower lymphocyte nadirs regardless of concurrent chemotherapy receipt (with concurrent: r = −0.26, P<.0001; without: r = −0.48, P<.0001). Analyses of lung DVH parameters revealed significant correlations at lower doses (lung V5-V10: P<.0001) that incrementally decreased and became nonsignificant at higher doses (lung V60-V70: P>.05). Of note, no significant associations were detected between GTV and lung DVH parameters with total leukocyte, neutrophil, or monocyte nadirs during RT or with lymphocyte count prior to RT. Multivariate analysis revealed larger GTV (P<.0001), receipt of concurrent chemotherapy (P<.0001), twice-daily radiation fractionation (P=.02), and stage III disease (P=.05) to be associated with lower lymphocyte nadirs. On univariate analysis, patients with higher lymphocyte nadirs exhibited significantly improved OS (hazard ratio [HR] = 0.51 per 10{sup 3} lymphocytes/μL, P=.01) and EFS (HR = 0.46 per 10{sup 3} lymphocytes/μL, P<.0001). These differences held on multivariate analyses, controlling for common disease and treatment characteristics including GTV. Conclusions: Lower lymphocyte nadirs during definitive RT were associated with larger GTVs and worse patient outcomes.« less

A Call for Conducting Multivariate Mixed Analyses

ERIC Educational Resources Information Center

Onwuegbuzie, Anthony J.

2016-01-01

Several authors have written methodological works that provide an introductory- and/or intermediate-level guide to conducting mixed analyses. Although these works have been useful for beginning and emergent mixed researchers, with very few exceptions, works are lacking that describe and illustrate advanced-level mixed analysis approaches. Thus,…

Quantitative methods for analysing cumulative effects on fish migration success: a review.

PubMed

Johnson, J E; Patterson, D A; Martins, E G; Cooke, S J; Hinch, S G

2012-07-01

It is often recognized, but seldom addressed, that a quantitative assessment of the cumulative effects, both additive and non-additive, of multiple stressors on fish survival would provide a more realistic representation of the factors that influence fish migration. This review presents a compilation of analytical methods applied to a well-studied fish migration, a more general review of quantitative multivariable methods, and a synthesis on how to apply new analytical techniques in fish migration studies. A compilation of adult migration papers from Fraser River sockeye salmon Oncorhynchus nerka revealed a limited number of multivariable methods being applied and the sub-optimal reliance on univariable methods for multivariable problems. The literature review of fisheries science, general biology and medicine identified a large number of alternative methods for dealing with cumulative effects, with a limited number of techniques being used in fish migration studies. An evaluation of the different methods revealed that certain classes of multivariable analyses will probably prove useful in future assessments of cumulative effects on fish migration. This overview and evaluation of quantitative methods gathered from the disparate fields should serve as a primer for anyone seeking to quantify cumulative effects on fish migration survival. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Neuropsychological tests for predicting cognitive decline in older adults

PubMed Central

Baerresen, Kimberly M; Miller, Karen J; Hanson, Eric R; Miller, Justin S; Dye, Richelin V; Hartman, Richard E; Vermeersch, David; Small, Gary W

2015-01-01

Summary Aim To determine neuropsychological tests likely to predict cognitive decline. Methods A sample of nonconverters (n = 106) was compared with those who declined in cognitive status (n = 24). Significant univariate logistic regression prediction models were used to create multivariate logistic regression models to predict decline based on initial neuropsychological testing. Results Rey–Osterrieth Complex Figure Test (RCFT) Retention predicted conversion to mild cognitive impairment (MCI) while baseline Buschke Delay predicted conversion to Alzheimer’s disease (AD). Due to group sample size differences, additional analyses were conducted using a subsample of demographically matched nonconverters. Analyses indicated RCFT Retention predicted conversion to MCI and AD, and Buschke Delay predicted conversion to AD. Conclusion Results suggest RCFT Retention and Buschke Delay may be useful in predicting cognitive decline. PMID:26107318

Multivariate Phylogenetic Comparative Methods: Evaluations, Comparisons, and Recommendations.

PubMed

Adams, Dean C; Collyer, Michael L

2018-01-01

Recent years have seen increased interest in phylogenetic comparative analyses of multivariate data sets, but to date the varied proposed approaches have not been extensively examined. Here we review the mathematical properties required of any multivariate method, and specifically evaluate existing multivariate phylogenetic comparative methods in this context. Phylogenetic comparative methods based on the full multivariate likelihood are robust to levels of covariation among trait dimensions and are insensitive to the orientation of the data set, but display increasing model misspecification as the number of trait dimensions increases. This is because the expected evolutionary covariance matrix (V) used in the likelihood calculations becomes more ill-conditioned as trait dimensionality increases, and as evolutionary models become more complex. Thus, these approaches are only appropriate for data sets with few traits and many species. Methods that summarize patterns across trait dimensions treated separately (e.g., SURFACE) incorrectly assume independence among trait dimensions, resulting in nearly a 100% model misspecification rate. Methods using pairwise composite likelihood are highly sensitive to levels of trait covariation, the orientation of the data set, and the number of trait dimensions. The consequences of these debilitating deficiencies are that a user can arrive at differing statistical conclusions, and therefore biological inferences, simply from a dataspace rotation, like principal component analysis. By contrast, algebraic generalizations of the standard phylogenetic comparative toolkit that use the trace of covariance matrices are insensitive to levels of trait covariation, the number of trait dimensions, and the orientation of the data set. Further, when appropriate permutation tests are used, these approaches display acceptable Type I error and statistical power. We conclude that methods summarizing information across trait dimensions, as well as pairwise composite likelihood methods should be avoided, whereas algebraic generalizations of the phylogenetic comparative toolkit provide a useful means of assessing macroevolutionary patterns in multivariate data. Finally, we discuss areas in which multivariate phylogenetic comparative methods are still in need of future development; namely highly multivariate Ornstein-Uhlenbeck models and approaches for multivariate evolutionary model comparisons. © The Author(s) 2017. Published by Oxford University Press on behalf of the Systematic Biology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of Components in Water on the Extraction of Herbal Medicine
—Advanced Approach Using Multivariate Analysis—

NASA Astrophysics Data System (ADS)

Kanzaki, Yasushi

Many kinds of water products have been offered commercially suggesting some strange efficacy beyond our scientific knowledge even now at which various advanced scientific and technological research have been highly promoted. However, it seems quite obvious that such a strange efficacy must be nonexistent. If such efficacy were really existing, it must be solved by some suitable scientific procedure. In this study, the extraction of paeoniflorin from paeoniae radix was examined by varying the kind of extracting water. Then, the result was analyzed using multivariate analysis where the effect on the extraction was assumed to be ascribed to the ionic species dissolved in each water examined. The dissolved species were analyzed by chemical and instrumental analyses. According to the multivariate analysis, the amount of extracted paeoniflorin (Y) was presented by the following regression equation. The result shows that pH, [Ca2+], and [HCO3 -] were significant parameters and the combination of Ca2+ and HCO3 - affected negatively on the extraction of paeoniflorin.
Y=28.11-0.71 pH-0.0034[Ca2+]-0.93[HCO3 -]
where [Ca2+] is the concentration of calcium ion and [HCO3 -] is that of bicarbonate ion.

Up-scaling of multi-variable flood loss models from objects to land use units at the meso-scale

NASA Astrophysics Data System (ADS)

Kreibich, Heidi; Schröter, Kai; Merz, Bruno

2016-05-01

Flood risk management increasingly relies on risk analyses, including loss modelling. Most of the flood loss models usually applied in standard practice have in common that complex damaging processes are described by simple approaches like stage-damage functions. Novel multi-variable models significantly improve loss estimation on the micro-scale and may also be advantageous for large-scale applications. However, more input parameters also reveal additional uncertainty, even more in upscaling procedures for meso-scale applications, where the parameters need to be estimated on a regional area-wide basis. To gain more knowledge about challenges associated with the up-scaling of multi-variable flood loss models the following approach is applied: Single- and multi-variable micro-scale flood loss models are up-scaled and applied on the meso-scale, namely on basis of ATKIS land-use units. Application and validation is undertaken in 19 municipalities, which were affected during the 2002 flood by the River Mulde in Saxony, Germany by comparison to official loss data provided by the Saxon Relief Bank (SAB).In the meso-scale case study based model validation, most multi-variable models show smaller errors than the uni-variable stage-damage functions. The results show the suitability of the up-scaling approach, and, in accordance with micro-scale validation studies, that multi-variable models are an improvement in flood loss modelling also on the meso-scale. However, uncertainties remain high, stressing the importance of uncertainty quantification. Thus, the development of probabilistic loss models, like BT-FLEMO used in this study, which inherently provide uncertainty information are the way forward.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

PubMed Central

Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. Results While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001) and LSA (OR = 1.393, p = 0.041). Conclusions Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms. PMID:26910518

Effects of coffee, smoking, and alcohol on liver function tests: a comprehensive cross-sectional study

PubMed Central

2012-01-01

Background Liver function tests (LFTs) can be affected by many factors and the proposed effects of coffee on LFT require a comprehensive evaluation. The aim of this study was to elucidate whether drinking coffee, smoking, or drinking alcohol have independent effects on LFTs in Korean health-check examinees. Methods We used the responses of 500 health-check examinees, who had participated in a self-administered questionnaire survey about coffee, alcohol drinking, and smoking habits. Results Coffee consumption was closely related to male gender, high body mass index (BMI), alcohol drinking, and smoking. On univariable and multivariable analyses, drinking coffee lowered serum levels of total protein, albumin, and aspartate aminotransferases (AST). On multivariable analyses, smoking raised serum γ-glutamyl transferase (GGT) level and decreased serum protein and albumin levels, while alcohol drinking raised GGT level after adjustment for age, gender, regular medication, BMI, coffee and alcohol drinking amounts, and smoking. Conclusions Coffee consumption, smoking, and alcohol drinking affect the individual components of LFT in different ways, and the above 3 habits each have an impact on LFTs. Therefore, their effects on LFTs should be carefully interpreted, and further study on the mechanism of the effects is warranted. PMID:23075166

The Impact of Tic Severity, Comorbidity and Peer Attachment on Quality of Life Outcomes and Functioning in Tourette's Syndrome: Parental Perspectives.

PubMed

O'Hare, Deirdre; Helmes, Edward; Eapen, Valsamma; Grove, Rachel; McBain, Kerry; Reece, John

2016-08-01

The aim of this controlled, community-based study based on data from parents of youth (aged 7-16 years) with Tourette's syndrome (TS; n = 86) and parents of age and gender matched peers (n = 108) was to test several hypotheses involving a range of variables salient to the TS population, including peer attachment, quality of life, severity of tics, comorbidity, and psychological, behavioural and social dysfunction. Multivariate between-group analyses confirmed that TS group youth experienced lower quality of life, increased emotional, behavioural and social difficulties, and elevated rates of insecure peer attachment relative to controls, as reported by their primary caregiver. Results also confirmed the main hypothesis that security of peer attachment would be associated with individual variability in outcomes for youth with TS. As predicted, multivariate within-TS group analyses determined strong relationships among adverse quality of life outcomes and insecure attachment to peers, increased tic severity, and the presence of comorbid disorder. Findings suggest that youth with TS are at increased risk for insecure peer attachment and that this might be an important variable impacting the quality of life outcomes for those diagnosed.

The High Prevalence of Incarceration History Among Black Men Who Have Sex With Men in the United States: Associations and Implications

PubMed Central

Magnus, Manya; Kuo, Irene; Wang, Lei; Liu, Ting-Yuan; Mayer, Kenneth H.

2014-01-01

Objectives. We examined lifetime incarceration history and its association with key characteristics among 1553 Black men who have sex with men (BMSM) recruited in 6 US cities. Methods. We conducted bivariate analyses of data collected from the HIV Prevention Trials Network 061 study from July 2009 through December 2011 to examine the relationship between incarceration history and demographic and psychosocial variables predating incarceration and multivariate logistic regression analyses to explore the associations between incarceration history and demographic and psychosocial variables found to be significant. We then used multivariate logistic regression models to explore the independent association between incarceration history and 6 outcome variables. Results. After adjusting for confounders, we found that increasing age, transgender identity, heterosexual or straight identity, history of childhood violence, and childhood sexual experience were significantly associated with incarceration history. A history of incarceration was also independently associated with any alcohol and drug use in the past 6 months. Conclusions. The findings highlight an elevated lifetime incarceration history among a geographically diverse sample of BMSM and the need to adequately assess the impact of incarceration among BMSM in the United States. PMID:24432948

A screening method based on UV-Visible spectroscopy and multivariate analysis to assess addition of filler juices and water to pomegranate juices.

PubMed

Boggia, Raffaella; Casolino, Maria Chiara; Hysenaj, Vilma; Oliveri, Paolo; Zunin, Paola

2013-10-15

Consumer demand for pomegranate juice has considerably grown, during the last years, for its potential health benefits. Since it is an expensive functional food, cheaper fruit juices addition (i.e., grape and apple juices) or its simple dilution, or polyphenols subtraction are deceptively used. At present, time-consuming analyses are used to control the quality of this product. Furthermore these analyses are expensive and require well-trained analysts. Thus, the purpose of this study was to propose a high-speed and easy-to-use shortcut. Based on UV-VIS spectroscopy and chemometrics, a screening method is proposed to quickly screening some common fillers of pomegranate juice that could decrease the antiradical scavenging capacity of pure products. The analytical method was applied to laboratory prepared juices, to commercial juices and to representative experimental mixtures at different levels of water and filler juices. The outcomes were evaluated by means of multivariate exploratory analysis. The results indicate that the proposed strategy can be a useful screening tool to assess addition of filler juices and water to pomegranate juices. Copyright © 2012 Elsevier Ltd. All rights reserved.

Chronic Conditions Among Children Investigated by Child Welfare: A National Sample

PubMed Central

Hurlburt, Michael S.; Heneghan, Amy M.; Zhang, Jinjin; Rolls-Reutz, Jennifer; Silver, Ellen J.; Fisher, Emily; Landsverk, John; Horwitz, Sarah McCue

2013-01-01

OBJECTIVE: To assess the presence of chronic health conditions (CHCs) among a nationally representative sample of children investigated by child welfare agencies. METHODS: The study included 5872 children, aged 0 to 17.5 years, whose families were investigated for maltreatment between February 2008 and April 2009. Using data from the second National Survey of Child and Adolescent Well-Being, we examined the proportion of children who had CHC. We developed 2 categorical and 2 noncategorical measures of CHC from the available data and analyzed them by using bivariate and multivariable analyses. RESULTS: Depending on the measure used, 30.6% to 49.0% of all children investigated were reported by their caregivers to have a CHC. Furthermore, the children identified by using diverse methods were not entirely overlapping. In the multivariable analyses, children with poorer health were more likely to be male, older, and receiving special educational services but not more likely to be in out-of-home placements. CONCLUSIONS: The finding that a much higher proportion of these children have CHC than in the general population underscores the substantial health problems of children investigated by child welfare agencies and the need to monitor their health carefully, regardless of their placement postinvestigation. PMID:23420907

Optimization of large animal MI models; a systematic analysis of control groups from preclinical studies.

PubMed

Zwetsloot, P P; Kouwenberg, L H J A; Sena, E S; Eding, J E; den Ruijter, H M; Sluijter, J P G; Pasterkamp, G; Doevendans, P A; Hoefer, I E; Chamuleau, S A J; van Hout, G P J; Jansen Of Lorkeers, S J

2017-10-27

Large animal models are essential for the development of novel therapeutics for myocardial infarction. To optimize translation, we need to assess the effect of experimental design on disease outcome and model experimental design to resemble the clinical course of MI. The aim of this study is therefore to systematically investigate how experimental decisions affect outcome measurements in large animal MI models. We used control animal-data from two independent meta-analyses of large animal MI models. All variables of interest were pre-defined. We performed univariable and multivariable meta-regression to analyze whether these variables influenced infarct size and ejection fraction. Our analyses incorporated 246 relevant studies. Multivariable meta-regression revealed that infarct size and cardiac function were influenced independently by choice of species, sex, co-medication, occlusion type, occluded vessel, quantification method, ischemia duration and follow-up duration. We provide strong systematic evidence that commonly used endpoints significantly depend on study design and biological variation. This makes direct comparison of different study-results difficult and calls for standardized models. Researchers should take this into account when designing large animal studies to most closely mimic the clinical course of MI and enable translational success.

A Bayesian Multivariate Receptor Model for Estimating Source Contributions to Particulate Matter Pollution using National Databases.

PubMed

Hackstadt, Amber J; Peng, Roger D

2014-11-01

Time series studies have suggested that air pollution can negatively impact health. These studies have typically focused on the total mass of fine particulate matter air pollution or the individual chemical constituents that contribute to it, and not source-specific contributions to air pollution. Source-specific contribution estimates are useful from a regulatory standpoint by allowing regulators to focus limited resources on reducing emissions from sources that are major contributors to air pollution and are also desired when estimating source-specific health effects. However, researchers often lack direct observations of the emissions at the source level. We propose a Bayesian multivariate receptor model to infer information about source contributions from ambient air pollution measurements. The proposed model incorporates information from national databases containing data on both the composition of source emissions and the amount of emissions from known sources of air pollution. The proposed model is used to perform source apportionment analyses for two distinct locations in the United States (Boston, Massachusetts and Phoenix, Arizona). Our results mirror previous source apportionment analyses that did not utilize the information from national databases and provide additional information about uncertainty that is relevant to the estimation of health effects.

Associations of Adolescent Hopelessness and Self-Worth With Pregnancy Attempts and Pregnancy Desire

PubMed Central

Fedorowicz, Anna R.; Schreiner, Pamela J.; Bolland, John M.

2014-01-01

Objectives. We examined the associations of pregnancy desire (ambivalence or happiness about a pregnancy in the next year) and recent pregnancy attempts with hopelessness and self-worth among low-income adolescents. Methods. To evaluate independent associations among the study variables, we conducted gender-stratified multivariable logistic regression analyses with data derived from 2285 sexually experienced 9- to 18-year-old participants in the Mobile Youth Survey between 2006 and 2009. Results. Fifty-seven percent of youths reported a desire for pregnancy and 9% reported pregnancy attempts. In multivariable analyses, hopelessness was positively associated and self-worth was negatively associated with pregnancy attempts among both female and male youths. Hopelessness was weakly associated (P = .05) with pregnancy desire among female youths. Conclusions. The negative association of self-worth and the positive association of hopelessness with pregnancy attempts among young men as well as young women and the association of hopelessness with pregnancy desire among young women raise questions about why pregnancy is apparently valued by youths who rate their social and cognitive competence as low and who live in an environment with few options for material success. PMID:24922147

The impact of ethnicity, family income, and parental education on children's health and use of health services.

PubMed Central

Flores, G; Bauchner, H; Feinstein, A R; Nguyen, U S

1999-01-01

OBJECTIVES: This study characterized ethnic disparities for children in demographics, health status, and use of services; explored whether ethnic subgroups (Puerto Rican, Cuban, and Mexican) have additional distinctive differences; and determined whether disparities are explained by differences in family income and parental education. METHODS: Bivariate and multivariate analyses of data on 99,268 children from the 1989-91 National Health Interview Surveys were conducted. RESULTS: Native American, Black, and Hispanic children are poorest (35%, 41% below poverty level vs 10% of Whites), least healthy (66%-74% in excellent or very good health vs 85% of Whites), and have the least well educated parents. Compared with Whites, non-White children average fewer doctor visits and are more likely to have excessive intervals between visits. Hispanic subgroup differences in demographics, health, and use of services equal or surpass differences among major ethnic groups. In multivariate analyses, almost all ethnic group disparities persisted after adjustment for family income, parental education, and other relevant covariates. CONCLUSIONS: Major ethnic groups and subgroups of children differ strikingly in demographics, health, and use of services; subgroup differences are easily overlooked; and most disparities persist even after adjustment for family income and parental education. PMID:10394317

Predictors of persistent pain after total knee arthroplasty: a systematic review and meta-analysis.

PubMed

Lewis, G N; Rice, D A; McNair, P J; Kluger, M

2015-04-01

Several studies have identified clinical, psychosocial, patient characteristic, and perioperative variables that are associated with persistent postsurgical pain; however, the relative effect of these variables has yet to be quantified. The aim of the study was to provide a systematic review and meta-analysis of predictor variables associated with persistent pain after total knee arthroplasty (TKA). Included studies were required to measure predictor variables prior to or at the time of surgery, include a pain outcome measure at least 3 months post-TKA, and include a statistical analysis of the effect of the predictor variable(s) on the outcome measure. Counts were undertaken of the number of times each predictor was analysed and the number of times it was found to have a significant relationship with persistent pain. Separate meta-analyses were performed to determine the effect size of each predictor on persistent pain. Outcomes from studies implementing uni- and multivariable statistical models were analysed separately. Thirty-two studies involving almost 30 000 patients were included in the review. Preoperative pain was the predictor that most commonly demonstrated a significant relationship with persistent pain across uni- and multivariable analyses. In the meta-analyses of data from univariate models, the largest effect sizes were found for: other pain sites, catastrophizing, and depression. For data from multivariate models, significant effects were evident for: catastrophizing, preoperative pain, mental health, and comorbidities. Catastrophizing, mental health, preoperative knee pain, and pain at other sites are the strongest independent predictors of persistent pain after TKA. © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Multitaper, Causal Decomposition for Stochastic, Multivariate Time Series: Application to High-Frequency Calcium Imaging Data.

PubMed

Sornborger, Andrew T; Lauderdale, James D

2016-11-01

Neural data analysis has increasingly incorporated causal information to study circuit connectivity. Dimensional reduction forms the basis of most analyses of large multivariate time series. Here, we present a new, multitaper-based decomposition for stochastic, multivariate time series that acts on the covariance of the time series at all lags, C ( τ ), as opposed to standard methods that decompose the time series, X ( t ), using only information at zero-lag. In both simulated and neural imaging examples, we demonstrate that methods that neglect the full causal structure may be discarding important dynamical information in a time series.

Quantifying the impact of between-study heterogeneity in multivariate meta-analyses

PubMed Central

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

2012-01-01

Measures that quantify the impact of heterogeneity in univariate meta-analysis, including the very popular I2 statistic, are now well established. Multivariate meta-analysis, where studies provide multiple outcomes that are pooled in a single analysis, is also becoming more commonly used. The question of how to quantify heterogeneity in the multivariate setting is therefore raised. It is the univariate R2 statistic, the ratio of the variance of the estimated treatment effect under the random and fixed effects models, that generalises most naturally, so this statistic provides our basis. This statistic is then used to derive a multivariate analogue of I2, which we call . We also provide a multivariate H2 statistic, the ratio of a generalisation of Cochran's heterogeneity statistic and its associated degrees of freedom, with an accompanying generalisation of the usual I2 statistic, . Our proposed heterogeneity statistics can be used alongside all the usual estimates and inferential procedures used in multivariate meta-analysis. We apply our methods to some real datasets and show how our statistics are equally appropriate in the context of multivariate meta-regression, where study level covariate effects are included in the model. Our heterogeneity statistics may be used when applying any procedure for fitting the multivariate random effects model. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22763950

FBST for Cointegration Problems

NASA Astrophysics Data System (ADS)

Diniz, M.; Pereira, C. A. B.; Stern, J. M.

2008-11-01

In order to estimate causal relations, the time series econometrics has to be aware of spurious correlation, a problem first mentioned by Yule [21]. To solve the problem, one can work with differenced series or use multivariate models like VAR or VEC models. In this case, the analysed series are going to present a long run relation i.e. a cointegration relation. Even though the Bayesian literature about inference on VAR/VEC models is quite advanced, Bauwens et al. [2] highlight that "the topic of selecting the cointegrating rank has not yet given very useful and convincing results." This paper presents the Full Bayesian Significance Test applied to cointegration rank selection tests in multivariate (VAR/VEC) time series models and shows how to implement it using available in the literature and simulated data sets. A standard non-informative prior is assumed.

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

Mouse Allergen, Lung Function, and Atopy in Puerto Rican Children

PubMed Central

Forno, Erick; Cloutier, Michelle M.; Datta, Soma; Paul, Kathryn; Sylvia, Jody; Calvert, Deanna; Thornton-Thompson, Sherell; Wakefield, Dorothy B.; Brehm, John; Hamilton, Robert G.; Alvarez, María; Colón-Semidey, Angel; Acosta-Pérez, Edna; Canino, Glorisa; Celedón, Juan C.

2012-01-01

Objective To examine the relation between mouse allergen exposure and asthma in Puerto Rican children. Methods Mus m 1, Der p 1, Bla g 2, and Fel d 1 allergens were measured in dust samples from homes of Puerto Rican children with (cases) and without (controls) asthma in Hartford, CT (n = 449) and San Juan (SJ), Puerto Rico (n = 678). Linear or logistic regression was used for the multivariate analysis of mouse allergen (Mus m 1) and lung function (FEV1 and FEV1/FVC) and allergy (total IgE and skin test reactivity (STR) to ≥1 allergen) measures. Results Homes in SJ had lower mouse allergen levels than those in Hartford. In multivariate analyses, mouse allergen was associated with higher FEV1 in cases in Hartford (+70.6 ml, 95% confidence interval (CI) = 8.6–132.7 ml, P = 0.03) and SJ (+45.1 ml, 95% CI =  −0.5 to 90.6 ml, P = 0.05). In multivariate analyses of controls, mouse allergen was inversely associated with STR to ≥1 allergen in non-sensitized children (odds ratio [OR] for each log-unit increment in Mus m 1 = 0.7, 95% CI = 0.5–0.9, P<0.01). In a multivariate analysis including all children at both study sites, each log-increment in mouse allergen was positively associated with FEV1 (+28.3 ml, 95% CI = 1.4–55.2 ml, P = 0.04) and inversely associated with STR to ≥1 allergen (OR for each log-unit increment in Mus m 1 = 0.8, 95% CI = 0.6–0.9, P<0.01). Conclusions Mouse allergen is associated with a higher FEV1 and lower odds of STR to ≥1 allergen in Puerto Rican children. This may be explained by the allergen itself or correlated microbial exposures. PMID:22815744

Increasing Awareness about HIV Prevention among Young People Who Initiated Injection Drug Use in a Canadian Setting, 1988–2014

PubMed Central

Bahji, Anees; Wood, Evan; Ahamad, Keith; Dong, Huiru; DeBeck, Kora; Milloy, M-J; Kerr, Thomas; Hayashi, Kanna

2015-01-01

Background Globally, harm reduction interventions, including needle and syringe programs (NSPs), have been shown to reduce HIV risks among people who inject drugs (PWID). However, little is known about the impact of these efforts on the circumstances of first injection. Therefore, we sought to identify changes in the awareness about HIV prevention and syringe borrowing at the time of first injection drug use in Vancouver, Canada, during a period of NSP expansion. Methods Data were drawn from prospective cohorts of PWID in Vancouver, who initiated injecting between 1988 and 2014. Multivariable regression was used to assess changes in the awareness about HIV and NSPs and syringe borrowing behaviour at first injection against calendar year of first injection. Results Among 1,044 participants (36.9% female), at the time of first injection 73.9% reported having known syringe sharing was an HIV risk, 54.1% reported having heard of NSPs, and 7.8% reported having borrowed a syringe used by others. In multivariable analyses, calendar year of first injection was independently and positively associated with awareness about HIV (adjusted prevalence ratio [APR]: 1.09; 95% confidence interval [CI]: 1.06, 1.11) and awareness about NSPs (APR: 1.18; 95% CI: 1.13, 1.24). While calendar year of first injection was significantly and negatively associated with syringe borrowing at first injection in bivariable analyses, the association did not remain significant in multivariable analyses (adjusted odds ratio: 0.90; 95% CI: 0.72, 1.14). Conclusions We found that awareness about HIV and NSPs at first injection have increased over time amongst PWID in this setting. However, declining trends in syringe borrowing at first injection were not determined after adjustment for socio-demographic characteristics. This suggests that HIV prevention efforts may have contributed to increased awareness about HIV prevention, but further research is needed to identify sub-populations at heightened risk of HIV at first injection. PMID:26514080

The effects of socioeconomic status, clinical factors, and genetic ancestry on pulmonary tuberculosis disease in northeastern Mexico.

PubMed

Young, Bonnie N; Rendón, Adrian; Rosas-Taraco, Adrian; Baker, Jack; Healy, Meghan; Gross, Jessica M; Long, Jeffrey; Burgos, Marcos; Hunley, Keith L

2014-01-01

Diverse socioeconomic and clinical factors influence susceptibility to tuberculosis (TB) disease in Mexico. The role of genetic factors, particularly those that differ between the parental groups that admixed in Mexico, is unclear. The objectives of this study are to identify the socioeconomic and clinical predictors of the transition from latent TB infection (LTBI) to pulmonary TB disease in an urban population in northeastern Mexico, and to examine whether genetic ancestry plays an independent role in this transition. We recruited 97 pulmonary TB disease patients and 97 LTBI individuals from a public hospital in Monterrey, Nuevo León. Socioeconomic and clinical variables were collected from interviews and medical records, and genetic ancestry was estimated for a subset of 142 study participants from 291,917 single nucleotide polymorphisms (SNPs). We examined crude associations between the variables and TB disease status. Significant predictors from crude association tests were analyzed using multivariable logistic regression. We also compared genetic ancestry between LTBI individuals and TB disease patients at 1,314 SNPs in 273 genes from the TB biosystem in the NCBI BioSystems database. In crude association tests, 12 socioeconomic and clinical variables were associated with TB disease. Multivariable logistic regression analyses indicated that marital status, diabetes, and smoking were independently associated with TB status. Genetic ancestry was not associated with TB disease in either crude or multivariable analyses. Separate analyses showed that LTBI individuals recruited from hospital staff had significantly higher European genetic ancestry than LTBI individuals recruited from the clinics and waiting rooms. Genetic ancestry differed between individuals with LTBI and TB disease at SNPs located in two genes in the TB biosystem. These results indicate that Monterrey may be structured with respect to genetic ancestry, and that genetic differences in TB susceptibility in parental populations may contribute to variation in disease susceptibility in the region.

The Effects of Socioeconomic Status, Clinical Factors, and Genetic Ancestry on Pulmonary Tuberculosis Disease in Northeastern Mexico

PubMed Central

Young, Bonnie N.; Rendón, Adrian; Rosas-Taraco, Adrian; Baker, Jack; Healy, Meghan; Gross, Jessica M.; Long, Jeffrey; Burgos, Marcos; Hunley, Keith L.

2014-01-01

Diverse socioeconomic and clinical factors influence susceptibility to tuberculosis (TB) disease in Mexico. The role of genetic factors, particularly those that differ between the parental groups that admixed in Mexico, is unclear. The objectives of this study are to identify the socioeconomic and clinical predictors of the transition from latent TB infection (LTBI) to pulmonary TB disease in an urban population in northeastern Mexico, and to examine whether genetic ancestry plays an independent role in this transition. We recruited 97 pulmonary TB disease patients and 97 LTBI individuals from a public hospital in Monterrey, Nuevo León. Socioeconomic and clinical variables were collected from interviews and medical records, and genetic ancestry was estimated for a subset of 142 study participants from 291,917 single nucleotide polymorphisms (SNPs). We examined crude associations between the variables and TB disease status. Significant predictors from crude association tests were analyzed using multivariable logistic regression. We also compared genetic ancestry between LTBI individuals and TB disease patients at 1,314 SNPs in 273 genes from the TB biosystem in the NCBI BioSystems database. In crude association tests, 12 socioeconomic and clinical variables were associated with TB disease. Multivariable logistic regression analyses indicated that marital status, diabetes, and smoking were independently associated with TB status. Genetic ancestry was not associated with TB disease in either crude or multivariable analyses. Separate analyses showed that LTBI individuals recruited from hospital staff had significantly higher European genetic ancestry than LTBI individuals recruited from the clinics and waiting rooms. Genetic ancestry differed between individuals with LTBI and TB disease at SNPs located in two genes in the TB biosystem. These results indicate that Monterrey may be structured with respect to genetic ancestry, and that genetic differences in TB susceptibility in parental populations may contribute to variation in disease susceptibility in the region. PMID:24728409

Prediabetes Is Associated with an Increased Risk of Testosterone Deficiency, Independent of Obesity and Metabolic Syndrome

PubMed Central

Ho, Chen-Hsun; Yu, Hong-Jeng; Wang, Chih-Yuan; Jaw, Fu-Shan; Hsieh, Ju-Ton; Liao, Wan-Chung; Pu, Yeong-Shiau; Liu, Shih-Ping

2013-01-01

Objective The association between type 2 diabetes and low testosterone has been well recognized. However, testosterone levels in men with prediabetes have been rarely reported. We aimed to investigate whether prediabetes was associated with an increased risk of testosterone deficiency. Methods This study included 1,306 men whose sex hormones was measured during a medical examination. Serum total testosterone and sex hormone-binding globulin were measured; free and bioavailable testosterone concentrations were calculated by Vermeulen’s formula. Prediabetes was defined by impaired fasting glucose (IFG), impaired postprandial glucose (IPG), or glycated hemoglobin (HbA1c) 5.7%-6.4%. Logistic regression was performed to obtain the odds ratios (OR) for subnormal total testosterone (<300 ng/dL) or free testosterone (<6 ng/dL) in prediabetic and diabetic men compared with normoglycemic individuals, while adjusting for age, BMI, waist circumference, and metabolic syndrome (MetS). Results Normoglycemia, prediabetes, and diabetes were diagnosed in 577 (44.2%), 543 (41.6%), and 186 (14.2%) men, respectively. Prediabetes was associated with an increased risk of subnormal total testosterone compared to normoglycemic individuals (age-adjusted OR=1.87; 95%CI=1.38-2.54). The risk remained significant in all multivariate analyses. After adjusting for MetS, the OR in prediabetic men equals that of diabetic patients (1.49 versus 1.50). IFG, IPG, and HbA1c 5.7%-6.4% were all associated with an increased risk of testosterone deficiency, with different levels of significance in multivariate analyses. However, neither prediabetes nor diabetes was associated with subnormal free testosterone in multivariate analyses. Conclusions Prediabetes is associated with an increased risk of testosterone deficiency, independent of obesity and MetS. After adjusting for MetS, the risk equals that of diabetes. Our data suggest that testosterone should be measured routinely in men with prediabetes. PMID:24069277

Mannitol and Outcome in Intracerebral Hemorrhage: Propensity Score and Multivariable Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial 2 Results.

PubMed

Wang, Xia; Arima, Hisatomi; Yang, Jie; Zhang, Shihong; Wu, Guojun; Woodward, Mark; Muñoz-Venturelli, Paula; Lavados, Pablo M; Stapf, Christian; Robinson, Thompson; Heeley, Emma; Delcourt, Candice; Lindley, Richard I; Parsons, Mark; Chalmers, John; Anderson, Craig S

2015-10-01

Mannitol is often used to reduce cerebral edema in acute intracerebral hemorrhage but without strong supporting evidence of benefit. We aimed to determine the impact of mannitol on outcome among participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial (INTERACT2). INTERACT2 was an international, open, blinded end point, randomized controlled trial of 2839 patients with spontaneous intracerebral hemorrhage (<6 hours) and elevated systolic blood pressure allocated to intensive (target systolic blood pressure, <140 mm Hg within 1 hour) or guideline-recommended (target systolic blood pressure, <180 mm Hg) blood pressure-lowering treatment. Propensity score and multivariable analyses were performed to investigate the relationship between mannitol treatment (within 7 days) and poor outcome, defined by death or major disability on the modified Rankin Scale score (3-6) at 90 days. There was no significant difference in poor outcome between mannitol (n=1533) and nonmannitol (n=993) groups: propensity score-matched odds ratio of 0.90 (95% confidence interval, 0.75-1.09; P=0.30) and multivariable odds ratio of 0.87 (95% confidence interval, 0.71-1.07; P=0.18). Although a better outcome was suggested in patients with larger (≥15 mL) than those with smaller (<15 mL) baseline hematomas who received mannitol (odds ratio, 0.52 [95% confidence interval, 0.35-0.78] versus odds ratio, 0.91 [95% confidence interval, 0.72-1.15]; P homogeneity<0.03 in propensity score analyses), the association was not consistent in analyses across other cutoff points (≥10 and ≥20 mL) and for differing grades of neurological severity. Mannitol was not associated with excess serious adverse events. Mannitol seems safe but might not improve outcome in patients with acute intracerebral hemorrhage. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00716079. © 2015 American Heart Association, Inc.

Iodine-131: An Effective Method for Treating Lymph Node Metastases of Differentiated Thyroid Cancer.

PubMed

He, Ying; Pan, Ming-Zhi; Huang, Jian-Min; Xie, Peng; Zhang, Fang; Wei, Ling-Ge

2016-12-15

BACKGROUND The aim of this study was to assess the efficacy of radioactive iodine-131 (¹³¹I) therapy for lymph node metastasis of differentiated thyroid cancer (DTC) and to identify influential factors using univariate and multivariate analyses to determine if identified factors influence the efficacy of treatment. MATERIAL AND METHODS This study included a retrospective review of 218 patients with histologically proven DTC in the post-operation stage. After thyroid tissue remnants were eliminated with ¹³¹I therapy, patients' lymph node status was confirmed by ultrasound and by ¹³¹I whole body scan regarding lymph node metastasis, and then patients were treated with ¹³¹I as appropriate. The treatment efficacy was assessed and possible influencing factors were identified using univariate and multivariate analyses. RESULTS The total effective rate of ¹³¹I therapy was 88.07% (including a cure rate of 20.64% and an improvement rate of 67.43%). The non-effective rate was 11.93%. Of the total 406 lymph nodes of 218 patients, 319 lymph nodes (78.57%) were judged to be effectively cured, including 133 (32.75%) lymph nodes that were totally eliminated and 186 (45.82%) lymph nodes that shrank. Eighty-seven (21.43%) of the 406 lymph nodes had no obvious change. No lymph nodes were found to be in a continuously enlarging state. Distant metastasis, size of lymph node, human serum thyroglobulin (HTG) level, and condition of thyroid remnants ablation were identified as the independent factors influencing the efficacy of treatment using univariate and multivariate analyses. CONCLUSIONS The use of ¹³¹I is a promising treatment for lymph node metastasis of DCT. Distant metastasis, size of lymph nodes, HTG level, and condition of thyroid remnant ablation were independent factors influencing the treatment efficacy.

Reprint of: Relationship between cataract severity and socioeconomic status.

PubMed

Wesolosky, Jason D; Rudnisky, Christopher J

2015-06-01

To determine the relationship between cataract severity and socioeconomic status (SES). Retrospective, observational case series. A total of 1350 eyes underwent phacoemulsification cataract extraction by a single surgeon using an Alcon Infiniti system. Cataract severity was measured using phaco time in seconds. SES was measured using area-level aggregate census data: median income, education, proportion of common-law couples, and employment rate. Preoperative best corrected visual acuity was obtained and converted to logarithm of the minimum angle of resolution values. For patients undergoing bilateral surgery, the generalized estimating equation was used to account for the correlation between eyes. Univariate analyses were performed using simple regression, and multivariate analyses were performed to account for variables with significant relationships (p < 0.05) on univariate testing. Sensitivity analyses were performed to assess the effect of including patient age in the controlled analyses. Multivariate analyses demonstrated that cataracts were more severe when the median income was lower (p = 0.001) and the proportion of common-law couples living in a patient's community (p = 0.012) and the unemployment rate (p = 0.002) were higher. These associations persisted even when controlling for patient age. Patients of lower SES have more severe cataracts. Copyright © 2015. Published by Elsevier Inc.

East-West gradient in cardio-vascular mortality in Austria: how much can we explain by following the pattern of risk factors?

PubMed Central

2011-01-01

Background Various studies show major regional differences in the prevalence of cardio-vascular disease morbidity and mortality, both in Europe and within European countries. In Austria, these differences are documented by an East-West gradient with declining morbidity and mortality rates when moving from the East to the West of the country. It was the aim of this study to analyse if, and to what extent, socio-demographic and socio-economic determinants, social resources and health behaviour can contribute to the clarification of this East-West gradient by conducting secondary analyses of an existing Austrian health dataset. Results The data were analysed using bivariate analyses, as well as univariate and multivariate logistic regression models. These analyses revealed significant East-West gradients for various risk factors, as well as socio-demographic and socio-economic health determinants. There was a gradual decrease of hypertension, diabetes mellitus, obesity, and psycho-social discomfort in both sexes, with the highest prevalences in those Austrian regions with the highest cardio-vascular mortality and a stepwise decrease to the regions with the lowest cardio-vascular mortality. Controlling for educational level significantly raised the odds for diabetes, hypertension and obesity. In the results of the multivariate analyses, factors that significantly and independently predicted diabetes mellitus were geographic location, psycho-social discomfort, lack of physical exercise, and age in both sexes. For women these factors additionally included a low educational level, lack of social support, and being born abroad. Conclusions Our study shows a clear gradual decline of cardio-vascular mortality and some of its risk factors from East to West in Austria. Concerning these risk factors, the geographic region and psycho-social discomfort showed the greatest association with diabetes mellitus, hypertension, and obesity. Hence, they contribute to the explanation of the variance in spatial cardio-vascular disease mortality. Yet, a large proportion of this variance remains unexplained. It would be of great importance to public health and preventive measures to take a closer look at spatial differences in cardio-vascular disease morbidity and mortality to better tailor programmes to the regional environments and settings. Our results also call for a greater importance of preventative measures for psycho-social discomfort and increase of social support. PMID:22082341

Central Body Fat Distribution Associates with Unfavorable Renal Hemodynamics Independent of Body Mass Index

PubMed Central

Zelle, Dorien M.; Bakker, Stephan J.L.; Navis, Gerjan

2013-01-01

Central distribution of body fat is associated with a higher risk of renal disease, but whether it is the distribution pattern or the overall excess weight that underlies this association is not well understood. Here, we studied the association between waist-to-hip ratio (WHR), which reflects central adiposity, and renal hemodynamics in 315 healthy persons with a mean body mass index (BMI) of 24.9 kg/m2 and a mean 125I-iothalamate GFR of 109 ml/min per 1.73 m2. In multivariate analyses, WHR was associated with lower GFR, lower effective renal plasma flow, and higher filtration fraction, even after adjustment for sex, age, mean arterial pressure, and BMI. Multivariate models produced similar results regardless of whether the hemodynamic measures were indexed to body surface area. Thus, these results suggest that central body fat distribution, independent of BMI, is associated with an unfavorable pattern of renal hemodynamic measures that could underlie the increased renal risk reported in observational studies. PMID:23578944

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.

Association of sleep disturbances with cognitive impairment and depression in maintenance hemodialysis patients.

PubMed

Rodriguez, Luke; Tighiouart, Hocine; Scott, Tammy; Lou, Kristina; Giang, Lena; Sorensen, Eric; Weiner, Daniel E; Sarnak, Mark J

2013-01-01

There are few data on the relationship of sleep with measures of cognitive function and symptoms of depression in dialysis patients. We evaluated the relationship of sleep with cognitive function and symptoms of depression in 168 hemodialysis patients, using multivariable linear and logistic regression. Sleep disturbances were assessed using the sleep subscale battery of the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) Health Experience Questionnaire. The cognitive battery assessed a broad range of functioning including global ability, verbal intelligence, supraspan learning, auditory retention, visual retention, attention/mental processing speed, visual construction/fluid reasoning and motor speed. Depressive symptoms were assessed using the Center for Epidemiological Studies of Depression (CESD) Scale, with depression indicated by a CESD score >16. Mean (SD) age of participants was 62 (17) years, 49% were women, 30% were African American and 33% had diabetes. There was no significant relationship between sleep score and performance on any neurocognitive test (p>0.13, for all multivariable analyses). The prevalence of depression increased from 16% in the highest quartile (best) of sleep score, to 31% in the lowest quartile (worst) of sleep score. In multivariable analyses, each 1 SD increase in sleep score was associated with a 2.18 (95% confidence interval, 1.07-3.29, p<0.001) lower CESD score. Results were consistent when considering individual components of both the CESD and sleep score. Disturbances in sleep are associated with symptoms of depression but not measures of cognitive function. Dialysis patients with disturbances in sleep should be screened for depression.

The role of objective cognitive dysfunction in subjective cognitive complaints after stroke.

PubMed

van Rijsbergen, M W A; Mark, R E; Kop, W J; de Kort, P L M; Sitskoorn, M M

2017-03-01

Objective cognitive performance (OCP) is often impaired in patients post-stroke but the consequences of OCP for patient-reported subjective cognitive complaints (SCC) are poorly understood. We performed a detailed analysis on the association between post-stroke OCP and SCC. Assessments of OCP and SCC were obtained in 208 patients 3 months after stroke. OCP was evaluated using conventional and ecologically valid neuropsychological tests. Levels of SCC were measured using the CheckList for Cognitive and Emotional (CLCE) consequences following stroke inventory. Multivariate hierarchical regression analyses were used to evaluate the association of OCP with CLCE scores adjusting for age, sex and intelligence quotient. Analyses were performed to examine the global extent of OCP dysfunction (based on the total number of impaired neuropsychological tests, i.e. objective cognitive impairment index) and for each OCP test separately using the raw neuropsychological (sub)test scores. The objective cognitive impairment index for global OCP was positively correlated with the CLCE score (Spearman's rho = 0.22, P = 0.003), which remained significant in multivariate adjusted models (β = 0.25, P = 0.01). Results for the separate neuropsychological tests indicated that only one task (the ecologically valid Rivermead Behavioural Memory Test) was independently associated with the CLCE in multivariate adjusted models (β = -0.34, P < 0.001). Objective neuropsychological test performance, as measured by the global dysfunction index or an ecologically valid memory task, was associated with SCC. These data suggest that cumulative deficits in multiple cognitive domains contribute to subjectively experienced poor cognitive abilities in daily life in patients post-stroke. © 2016 EAN.

[Relationship between highly sensitive cardiac troponin T and sepsis and outcome in critically ill patients].

PubMed

Wang, T T; Jiang, L

2017-10-01

Objective: To investigate the prognostic value of highly sensitive cardiac Troponin T (hs-cTn T) for sepsis in critically ill patients. Methods: Patients estimated to stay in the ICU of Fuxing Hospital for more than 24h were enrolled at from March 2014 to December 2014. Serum hs-cTn T was tested within two hours. Univariate and multivariate linear regression analyses were used to determine the association of variables with the hs-cTn T. Multivariable logistic regression analysis was used to evaluate the risk factors of 28-day mortality. Results: A total of 125 patients were finally enrolled including 68 patients with sepsis and 57 without. The levels of hs-cTn T in sepsis and non-sepsis groups were significantly different[52.0(32.5, 87.5) ng/L vs 14.0(6.5, 29.0) ng/L respectively, P <0.001]. In sepsis group, hs-cTn T among common sepsis, severe sepsis and septic shock were similar. Hs-cTn T was significantly higher in non-survivors than survivors [27(13, 52)ng/L vs 44.5(28.8, 83.5)ng/L, P <0.001]. Age, sepsis, serum creatinine were independent risk factors affecting hs-cTn T by multivariate linear regression analyses. But hs-cTn T was not a risk factor for death. Conclusion: Patients with sepsis had higher serum hs-cTn T than those without sepsis. but it was not found to be associated with the severity of sepsis.

A statistical framework for neuroimaging data analysis based on mutual information estimated via a gaussian copula.

PubMed

Ince, Robin A A; Giordano, Bruno L; Kayser, Christoph; Rousselet, Guillaume A; Gross, Joachim; Schyns, Philippe G

2017-03-01

We begin by reviewing the statistical framework of information theory as applicable to neuroimaging data analysis. A major factor hindering wider adoption of this framework in neuroimaging is the difficulty of estimating information theoretic quantities in practice. We present a novel estimation technique that combines the statistical theory of copulas with the closed form solution for the entropy of Gaussian variables. This results in a general, computationally efficient, flexible, and robust multivariate statistical framework that provides effect sizes on a common meaningful scale, allows for unified treatment of discrete, continuous, unidimensional and multidimensional variables, and enables direct comparisons of representations from behavioral and brain responses across any recording modality. We validate the use of this estimate as a statistical test within a neuroimaging context, considering both discrete stimulus classes and continuous stimulus features. We also present examples of analyses facilitated by these developments, including application of multivariate analyses to MEG planar magnetic field gradients, and pairwise temporal interactions in evoked EEG responses. We show the benefit of considering the instantaneous temporal derivative together with the raw values of M/EEG signals as a multivariate response, how we can separately quantify modulations of amplitude and direction for vector quantities, and how we can measure the emergence of novel information over time in evoked responses. Open-source Matlab and Python code implementing the new methods accompanies this article. Hum Brain Mapp 38:1541-1573, 2017. © 2016 Wiley Periodicals, Inc. 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Effect of pretreatment with statins on ischemic stroke outcomes.

PubMed

Reeves, Mathew J; Gargano, Julia Warner; Luo, Zhehui; Mullard, Andrew J; Jacobs, Bradley S; Majid, Arshad

2008-06-01

Statins reduce the risk of stroke in at-risk populations and may improve outcomes in patients taking statins before an ischemic stroke (IS). Our objectives were to examine the effects of pretreatment with statins on poor outcome in IS patients. Over a 6-month period all acute IS admissions were prospectively identified in 15 hospitals participating in a statewide acute stroke registry. Poor stroke outcome was defined as modified Rankin score >/=4 at discharge (ie, moderate-severe disability or death). Multivariable logistic regression models and matched propensity score analyses were used to quantify the effect of statin pretreatment on poor outcome. Of 1360 IS patients, 23% were using statins before their stroke event and 42% had a poor stroke outcome. After multivariable adjustment, pretreatment with statins was associated with lower odds of poor outcome (OR=0.74, 95% CI 0.52, 1.02). A significant interaction (P<0.01) was found between statin use and race. In whites, statins were associated with statistically significantly lower odds of poor outcome (OR=0.61, 95% CI 0.42, 0.86), but in blacks statins were associated with a nonstatistically significant increase in poor outcome (OR=1.82, 95% CI 0.98, 3.39). Matched propensity score analyses were consistent with the multivariable model results. Pretreatment with statins was associated with better stroke outcomes in whites, but we found no evidence of a beneficial effect of statins in blacks. These findings indicate the need for further studies, including randomized trials, to examine differential effects of statins on ischemic stroke outcomes among whites and blacks.

Inter-hospital variations in caesarean sections. A risk adjusted comparison in the Valencia public hospitals

PubMed Central

Librero, J.; Peiro, S.; Calderon, S. M.

2000-01-01

BACKGROUND—The aim of this study was to describe the variability in caesarean rates in the public hospitals in the Valencia Region, Spain, and to analyse the association between caesarean sections and clinical and extra-clinical factors.
METHODS—Analysis of data contained in the Minimum Basic Data Set (MBDS) compiled for all births in 11 public hospitals in Valencia during 1994-1995 (n=36 819). Bivariate and multivariate analyses were used to evaluate the association between caesarean section rates and specific risk factors. The multivariate model was used to construct predictions about caesarean rates for each hospital, for comparison with rates observed.
RESULTS—Caesarean rates were 17.6% (inter-hospital range: 14.7% to 25.0%), with ample variability between hospitals in the diagnosis of maternal-fetal risk factors (particularly dystocia and fetal distress), and the indication for caesarean in the presence of these factors. Multivariate analysis showed that maternal-fetal risk factors correlated strongly with caesarean section, although extra-clinical factors, such as the day of the week, also correlated positively. After adjusting for the risk factors, the inter-hospital variation in caesarean rates persisted.
CONCLUSIONS—Although certain limitations (imprecision of some diagnoses and information biases in the MBDS) make it impossible to establish unequivocal conclusions, results show a high degree of variability among hospitals when opting for caesarean section. This variability cannot be justified by differences in obstetric risks.


Keywords: hospital utilisation; medical practice variation; caesarean section; administrative databases PMID:10890876

Relationship between alcohol intake, body fat, and physical activity – a population-based study

PubMed Central

Liangpunsakul, Suthat; Crabb, David W.; Qi, Rong

2010-01-01

Objectives Aside from fat, ethanol is the macronutrient with the highest energy density. Whether the energy derived from ethanol affects the body composition and fat mass is debatable. We investigated the relationship between alcohol intake, body composition, and physical activity in the US population using the third National Health and Nutrition Examination Survey (NHANES III). Methods Ten thousand five hundred and fifty subjects met eligible criteria and constituted our study cohort. Estimated percent body fat and resting metabolic rate were calculated based on the sum of the skinfolds. Multivariate regression analyses were performed accounting for the study sampling weight. Results In both genders, moderate and hazardous alcohol drinkers were younger (p<0.05), had significantly lower BMI (P<0.01) and body weight (p<0.01) than controls, non drinkers. Those with hazardous alcohol consumption had significantly less physical activity compared to those with no alcohol use and moderate drinkers in both genders. Female had significantly higher percent body fat than males. In the multivariate linear regression analyses, the levels of alcohol consumption were found to be an independent predictor associated with lower percent body fat only in male subjects. Conclusions Our results showed that alcoholics are habitually less active and that alcohol drinking is an independent predictor of lower percent body fat especially in male alcoholics. PMID:20696406

Parental Opinions and Attitudes about Children's Vaccination Safety in Silesian Voivodeship, Poland.

PubMed

Braczkowska, Bogumiła; Kowalska, Małgorzata; Barański, Kamil; Gajda, Maksymilian; Kurowski, Tomasz; Zejda, Jan E

2018-04-15

Despite mandatory vaccinations in Poland, the final decision on vaccination in children is taken by their parents or legal guardians. Understanding parents' attitudes and opinions regarding vaccinations is essential for planning and undertaking extensive and properly targeted educational actions aimed at preventing their hesitancy. In 2016, a cross-sectional study was conducted in the Silesian Voivodeship (Poland) in 11 randomly selected educational institutions. The authors' self-administered questionnaire contained 24 mixed-type questions. It was distributed among 3000 parents or legal guardians of children aged 6-13 years; prior consent of the relevant bioethics committee had been obtained. The response rate was 41.3% ( N = 1239). Data were analysed using descriptive and analytical statistics, and focused on parental opinions regarding the safety of vaccines. Results of simple and multivariable analyses showed that perceived risk of adverse vaccine reaction (AVR), contraindications and perception of the qualification procedure for vaccination as substandard were significant factors associated with the rating of children's vaccination as unsafe ( p < 0.001). Respondents with a lower level of education, compared with those with higher, more often declared vaccinations to be safe ( p = 0.03); however, results of multivariable analysis did not confirm that effect. AVR occurrence, finding of contraindication to vaccinations and perception of qualification procedure for vaccination were found to be the most important factors responsible for influencing general public opinions in the field of vaccination safety.

Causal diagrams and multivariate analysis I: a quiver full of arrows.

PubMed

Jupiter, Daniel C

2014-01-01

How do we know which variables we should include in our multivariate analyses? What role does each variable play in our understanding of the analysis? In this article I begin a discussion of these issues and describe 2 different types of studies for which this problem must be handled in different ways. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Factors Affecting Female Teachers' Attitudes toward Help-Seeking or Help-Avoidance in Coping with Behavioral Problems

ERIC Educational Resources Information Center

Inbar-Furst, Hagit; Gumpel, Thomas P.

2015-01-01

Questionnaires were given to 392 elementary school teachers to examine help-seeking or help-avoidance in dealing with classroom behavioral problems. Scale validity was examined through a series of exploratory and confirmatory factor analyses. Using a series of multivariate regression analyses and structural equation modeling, we identified…

Multielement geochemistry identifies the spatial pattern of soil and sediment contamination in an urban parkland, Western Australia.

PubMed

Rate, Andrew W

2018-06-15

Urban environments are dynamic and highly heterogeneous, and multiple additions of potential contaminants are likely on timescales which are short relative to natural processes. The likely sources and location of soil or sediment contamination in urban environment should therefore be detectable using multielement geochemical composition combined with rigorously applied multivariate statistical techniques. Soil, wetland sediment, and street dust was sampled along intersecting transects in Robertson Park in metropolitan Perth, Western Australia. Samples were analysed for near-total concentrations of multiple elements (including Cd, Ce, Co, Cr, Cu, Fe, Gd, La, Mn, Nd, Ni, Pb, Y, and Zn), as well as pH, and electrical conductivity. Samples at some locations within Robertson Park had high concentrations of potentially toxic elements (Pb above Health Investigation Limits; As, Ba, Cu, Mn, Ni, Pb, V, and Zn above Ecological Investigation Limits). However, these concentrations carry low risk due to the main land use as recreational open space, the low proportion of samples exceeding guideline values, and a tendency for the highest concentrations to be located within the less accessible wetland basin. The different spatial distributions of different groups of contaminants was consistent with different inputs of contaminants related to changes in land use and technology over the history of the site. Multivariate statistical analyses reinforced the spatial information, with principal component analysis identifying geochemical associations of elements which were also spatially related. A multivariate linear discriminant model was able to discriminate samples into a-priori types, and could predict sample type with 84% accuracy based on multielement composition. The findings suggest substantial advantages of characterising a site using multielement and multivariate analyses, an approach which could benefit investigations of other sites of concern. Copyright © 2018 Elsevier B.V. All rights reserved.

An Exploratory Study of Fatigue and Physical Activity in Canadian Thyroid Cancer Patients.

PubMed

Alhashemi, Ahmad; Jones, Jennifer M; Goldstein, David P; Mina, Daniel Santa; Thabane, Lehana; Sabiston, Catherine M; Chang, Eugene K; Brierley, James D; Sawka, Anna M

2017-09-01

Fatigue is common among cancer survivors, but fatigue in thyroid cancer (TC) survivors may be under-appreciated. This study investigated the severity and prevalence of moderate and severe fatigue in TC survivors. Potential predictive factors, including physical activity, were explored. A cross-sectional, written, self-administered TC patient survey and retrospective chart review were performed in an outpatient academic Endocrinology clinic in Toronto, Canada. The primary outcome measure was the global fatigue score measured by the Brief Fatigue Inventory (BFI). Physical activity was evaluated using the International Physical Activity Questionnaire-7 day (IPAQ-7). Predictors of BFI global fatigue score were explored in univariate analyses and a multivariable linear regression model. The response rate was 63.1% (205/325). Three-quarters of the respondents were women (152/205). The mean age was 52.5 years, and the mean time since first TC surgery was 6.8 years. The mean global BFI score was 3.5 (standard deviation 2.4) out of 10 (10 is worst). The prevalence of moderate-severe fatigue (global BFI score 4.1-10 out of 10) was 41.4% (84/203). Individuals who were unemployed or unable to work due to disability reported significantly higher levels of fatigue compared to the rest of the study population, in uni-and multivariable analyses. Furthermore, increased physical activity was associated with reduced fatigue in uni- and multivariable analyses. Other socio-demographic, disease, or biochemical variables were not significantly associated with fatigue in the multivariable model. Moderate or severe fatigue was reported in about 4/10 TC survivors. Independent predictors of worse fatigue included unemployment and reduced physical activity.

Multivariate analyses of peripheral blood leukocyte transcripts distinguish Alzheimer's, Parkinson's, control, and those at risk for developing Alzheimer's.

PubMed

Delvaux, Elaine; Mastroeni, Diego; Nolz, Jennifer; Chow, Nienwen; Sabbagh, Marwan; Caselli, Richard J; Reiman, Eric M; Marshall, Frederick J; Coleman, Paul D

2017-10-01

The need for a reliable, simple, and inexpensive blood test for Alzheimer's disease (AD) suitable for use in a primary care setting is widely recognized. This has led to a large number of publications describing blood tests for AD, which have, for the most part, not been replicable. We have chosen to examine transcripts expressed by the cellular, leukocyte compartment of blood. We have used hypothesis-based cDNA arrays and quantitative PCR to quantify the expression of selected sets of genes followed by multivariate analyses in multiple independent samples. Rather than a single study with no replicates, we chose an experimental design in which there were multiple replicates using different platforms and different sample populations. We have divided 177 blood samples and 27 brain samples into multiple replicates to demonstrate the ability to distinguish early clinical AD (Clinical Dementia Rating scale 0.5), Parkinson's disease (PD), and cognitively unimpaired APOE4 homozygotes, as well as to determine persons at risk for future cognitive impairment with significant accuracy. We assess our methods in a training/test set and also show that the variables we use distinguish AD, PD, and control brain. Importantly, we describe the variability of the weights assigned to individual transcripts in multivariate analyses in repeated studies and suggest that the variability we describe may be the cause of inability to repeat many earlier studies. Our data constitute a proof of principle that multivariate analysis of the transcriptome related to cell stress and inflammation of peripheral blood leukocytes has significant potential as a minimally invasive and inexpensive diagnostic tool for diagnosis and early detection of risk for AD. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

A reply to Zigler and Seitz.

PubMed

Neman, R

1975-03-01

The Zigler and Seitz (1975) critique was carefully examined with respect to the conclusions of the Neman et al. (1975) study. Particular attention was given to the following questions: (a) did experimenter bias or commitment account for the results, (b) were unreliable and invalid psychometric instruments used, (c) were the statistical analyses insufficient or incorrect, (d) did the results reflect no more than the operation of chance, and (e) were the results biased by artifactually inflated profile scores. Experimenter bias and commitment were shown to be insufficient to account for the results; a further review of Buros (1972) showed that there was no need for apprehension about the testing instruments; the statistical analyses were shown to exceed prevailing standards for research reporting; the results were shown to reflect valid findings at the .05 probability level; and the Neman et al. (1975) results for the profile measure were equally significant using either "raw" neurological scores or "scales" neurological age scores. Zigler, Seitz, and I agreed on the needs for (a) using multivariate analyses, where applicable, in studies having more than one dependent variable; (b) defining the population for which sensorimotor training procedures may be appropriately prescribed; and (c) validating the profile measure as a tool to assess neurological disorganization.

Multivariate Meta-Analysis of Genetic Association Studies: A Simulation Study

PubMed Central

Neupane, Binod; Beyene, Joseph

2015-01-01

In a meta-analysis with multiple end points of interests that are correlated between or within studies, multivariate approach to meta-analysis has a potential to produce more precise estimates of effects by exploiting the correlation structure between end points. However, under random-effects assumption the multivariate estimation is more complex (as it involves estimation of more parameters simultaneously) than univariate estimation, and sometimes can produce unrealistic parameter estimates. Usefulness of multivariate approach to meta-analysis of the effects of a genetic variant on two or more correlated traits is not well understood in the area of genetic association studies. In such studies, genetic variants are expected to roughly maintain Hardy-Weinberg equilibrium within studies, and also their effects on complex traits are generally very small to modest and could be heterogeneous across studies for genuine reasons. We carried out extensive simulation to explore the comparative performance of multivariate approach with most commonly used univariate inverse-variance weighted approach under random-effects assumption in various realistic meta-analytic scenarios of genetic association studies of correlated end points. We evaluated the performance with respect to relative mean bias percentage, and root mean square error (RMSE) of the estimate and coverage probability of corresponding 95% confidence interval of the effect for each end point. Our simulation results suggest that multivariate approach performs similarly or better than univariate method when correlations between end points within or between studies are at least moderate and between-study variation is similar or larger than average within-study variation for meta-analyses of 10 or more genetic studies. Multivariate approach produces estimates with smaller bias and RMSE especially for the end point that has randomly or informatively missing summary data in some individual studies, when the missing data in the endpoint are imputed with null effects and quite large variance. PMID:26196398

Multivariate Meta-Analysis of Genetic Association Studies: A Simulation Study.

PubMed

Neupane, Binod; Beyene, Joseph

2015-01-01

In a meta-analysis with multiple end points of interests that are correlated between or within studies, multivariate approach to meta-analysis has a potential to produce more precise estimates of effects by exploiting the correlation structure between end points. However, under random-effects assumption the multivariate estimation is more complex (as it involves estimation of more parameters simultaneously) than univariate estimation, and sometimes can produce unrealistic parameter estimates. Usefulness of multivariate approach to meta-analysis of the effects of a genetic variant on two or more correlated traits is not well understood in the area of genetic association studies. In such studies, genetic variants are expected to roughly maintain Hardy-Weinberg equilibrium within studies, and also their effects on complex traits are generally very small to modest and could be heterogeneous across studies for genuine reasons. We carried out extensive simulation to explore the comparative performance of multivariate approach with most commonly used univariate inverse-variance weighted approach under random-effects assumption in various realistic meta-analytic scenarios of genetic association studies of correlated end points. We evaluated the performance with respect to relative mean bias percentage, and root mean square error (RMSE) of the estimate and coverage probability of corresponding 95% confidence interval of the effect for each end point. Our simulation results suggest that multivariate approach performs similarly or better than univariate method when correlations between end points within or between studies are at least moderate and between-study variation is similar or larger than average within-study variation for meta-analyses of 10 or more genetic studies. Multivariate approach produces estimates with smaller bias and RMSE especially for the end point that has randomly or informatively missing summary data in some individual studies, when the missing data in the endpoint are imputed with null effects and quite large variance.

Use of Health Care Claims Data to Study Patients with Ophthalmologic Conditions

PubMed Central

Stein, Joshua D.; Lum, Flora; Lee, Paul P.; Rich, William L.; Coleman, Anne L.

2014-01-01

Objective To describe what information is or is not included in health care claims data, provide an overview of the main advantages and limitations of performing analyses using health care claims data, and offer general guidance on how to report and interpret findings of ophthalmology-related claims data analyses. Design Systematic review. Participants Not applicable. Methods A literature review and synthesis of methods for claims-based data analyses. Main Outcome Measures Not applicable. Results Some advantages of using claims data for analyses include large, diverse sample sizes, longitudinal follow-up, lack of selection bias, and potential for complex, multivariable modeling. The disadvantages include (a) the inherent limitations of claims data, such as incomplete, inaccurate, or missing data, or the lack of specific billing codes for some conditions; and (b) the inability, in some circumstances, to adequately evaluate the appropriateness of care. In general, reports of claims data analyses should include clear descriptions of the following methodological elements: the data source, the inclusion and exclusion criteria, the specific billing codes used, and the potential confounding factors incorporated in the multivariable models. Conclusions The use of claims data for research is expected to increase with the enhanced availability of data from Medicare and other sources. The use of claims data to evaluate resource use and efficiency and to determine the basis for supplementary payment methods for physicians is anticipated. Thus, it will be increasingly important for eye care providers to use accurate and descriptive codes for billing. Adherence to general guidance on the reporting of claims data analyses, as outlined in this article, is important to enhance the credibility and applicability of findings. Guidance on optimal ways to conduct and report ophthalmology-related investigations using claims data will likely continue to evolve as health services researchers refine the metrics to analyze large administrative data sets. PMID:24433971

A guide to statistical analysis in microbial ecology: a community-focused, living review of multivariate data analyses.

PubMed

Buttigieg, Pier Luigi; Ramette, Alban

2014-12-01

The application of multivariate statistical analyses has become a consistent feature in microbial ecology. However, many microbial ecologists are still in the process of developing a deep understanding of these methods and appreciating their limitations. As a consequence, staying abreast of progress and debate in this arena poses an additional challenge to many microbial ecologists. To address these issues, we present the GUide to STatistical Analysis in Microbial Ecology (GUSTA ME): a dynamic, web-based resource providing accessible descriptions of numerous multivariate techniques relevant to microbial ecologists. A combination of interactive elements allows users to discover and navigate between methods relevant to their needs and examine how they have been used by others in the field. We have designed GUSTA ME to become a community-led and -curated service, which we hope will provide a common reference and forum to discuss and disseminate analytical techniques relevant to the microbial ecology community. © 2014 The Authors. FEMS Microbiology Ecology published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Using empirical Bayes predictors from generalized linear mixed models to test and visualize associations among longitudinal outcomes.

PubMed

Mikulich-Gilbertson, Susan K; Wagner, Brandie D; Grunwald, Gary K; Riggs, Paula D; Zerbe, Gary O

2018-01-01

Medical research is often designed to investigate changes in a collection of response variables that are measured repeatedly on the same subjects. The multivariate generalized linear mixed model (MGLMM) can be used to evaluate random coefficient associations (e.g. simple correlations, partial regression coefficients) among outcomes that may be non-normal and differently distributed by specifying a multivariate normal distribution for their random effects and then evaluating the latent relationship between them. Empirical Bayes predictors are readily available for each subject from any mixed model and are observable and hence, plotable. Here, we evaluate whether second-stage association analyses of empirical Bayes predictors from a MGLMM, provide a good approximation and visual representation of these latent association analyses using medical examples and simulations. Additionally, we compare these results with association analyses of empirical Bayes predictors generated from separate mixed models for each outcome, a procedure that could circumvent computational problems that arise when the dimension of the joint covariance matrix of random effects is large and prohibits estimation of latent associations. As has been shown in other analytic contexts, the p-values for all second-stage coefficients that were determined by naively assuming normality of empirical Bayes predictors provide a good approximation to p-values determined via permutation analysis. Analyzing outcomes that are interrelated with separate models in the first stage and then associating the resulting empirical Bayes predictors in a second stage results in different mean and covariance parameter estimates from the maximum likelihood estimates generated by a MGLMM. The potential for erroneous inference from using results from these separate models increases as the magnitude of the association among the outcomes increases. Thus if computable, scatterplots of the conditionally independent empirical Bayes predictors from a MGLMM are always preferable to scatterplots of empirical Bayes predictors generated by separate models, unless the true association between outcomes is zero.

Detecting spatial regimes in ecosystems

USGS Publications Warehouse

Sundstrom, Shana M.; Eason, Tarsha; Nelson, R. John; Angeler, David G.; Barichievy, Chris; Garmestani, Ahjond S.; Graham, Nicholas A.J.; Granholm, Dean; Gunderson, Lance; Knutson, Melinda; Nash, Kirsty L.; Spanbauer, Trisha; Stow, Craig A.; Allen, Craig R.

2017-01-01

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change.

Exploring the relationship between entheseal changes and physical activity: a multivariate study.

PubMed

Milella, Marco; Cardoso, Francisca Alves; Assis, Sandra; Lopreno, Geneviève Perréard; Speith, Nivien

2015-02-01

Analyses of entheseal changes (EC) in identified skeletal samples employ a common research strategy based on the comparison between occupations grouped on the basis of shared biomechanical and/or social characteristics. Results from this approach are often ambiguous, with some studies that point to differences in EC between occupational samples and others failing to provide evidence of behavioral effects on EC. Here we investigate patterns of EC among documented occupations by means of a multivariate analysis of robusticity scores in nine postcranial entheses from a large (N = 372) contemporary skeletal sample including specimens from one Italian and two Portuguese identified collections. Data on entheseal robusticity, analyzed by pooled sides as well by separated sides and levels of asymmetry, are converted in binary scores and then analyzed through nonlinear principal component analysis and hierarchical cluster analysis. Results of these analyses are then used for the classification of occupations. Differences between occupational classes are tested by MANOVA and pairwise Hotelling's test. Results evidence three classes which separate occupations related to farming, physically demanding but generalized occupation, and physically undemanding occupations, with the more consistent differences between the first and the last classes. Our results are consistent with differences in biomechanical behavior between the occupations included in each class, and point to the physical and social specificity of farming activities. On the other hand, our study exemplifies the usefulness of alternative analytical protocols for the investigation of EC, and the value of research designs devoid of a priori assumptions for the test of biocultural hypotheses. Copyright © 2014 Wiley Periodicals, Inc.

Factors associated with seasonal influenza vaccination in pregnant women.

PubMed

Henninger, Michelle L; Irving, Stephanie A; Thompson, Mark; Avalos, Lyndsay Ammon; Ball, Sarah W; Shifflett, Pat; Naleway, Allison L

2015-05-01

This observational study followed a cohort of pregnant women during the 2010-2011 influenza season to determine factors associated with vaccination. Participants were 1105 pregnant women who completed a survey assessing health beliefs related to vaccination upon enrollment and were then followed to determine vaccination status by the end of the 2010-2011 influenza season. We conducted univariate and multivariate analyses to explore factors associated with vaccination status and a factor analysis of survey items to identify health beliefs associated with vaccination. Sixty-three percent (n=701) of the participants were vaccinated. In the univariate analyses, multiple factors were associated with vaccination status, including maternal age, race, marital status, educational level, and gravidity. Factor analysis identified two health belief factors associated with vaccination: participant's positive views (factor 1) and negative views (factor 2) of influenza vaccination. In a multivariate logistic regression model, factor 1 was associated with increased likelihood of vaccination (adjusted odds ratio [aOR]=2.18; 95% confidence interval [CI]=1.72-2.78), whereas factor 2 was associated with decreased likelihood of vaccination (aOR=0.36; 95% CI=0.28-0.46). After controlling for the two health belief factors in multivariate analyses, demographic factors significant in univariate analyses were no longer significant. Women who received a provider recommendation were about three times more likely to be vaccinated (aOR=3.14; 95% CI=1.99-4.96). Pregnant women's health beliefs about vaccination appear to be more important than demographic and maternal factors previously associated with vaccination status. Provider recommendation remains one of the most critical factors influencing vaccination during pregnancy.

'Left behind' but not left alone: parental migration & the psychosocial health of children in Moldova.

PubMed

Vanore, Michaella; Mazzucato, Valentina; Siegel, Melissa

2015-05-01

In Moldova, large-scale and rapidly feminised migration flows have inspired a wave of qualitative reports on children "left behind". Despite this recent interest, few studies have empirically evaluated the effects of parental migration on the psychosocial health of such children. Using data collected from a nationally-representative household survey conducted in Moldova between September 2011 and February 2012, this paper analyses the psychosocial health outcomes of children of migrant parents by comparing them with children without migrant parents (n = 1979). Child psychosocial health is measured through caregiver-reported Strengths and Difficulties Questionnaire (SDQ) scores. Multivariate regression analyses show that parental migration seldom corresponds to worse emotional symptoms outcomes but does correspond to increased conduct problems. Separate analyses for male and female children show significant gendered differences. The results partially contest the negative results that have been the subject of qualitative reports and, in particular, demonstrate that the migration of mothers infrequently results in worse psychosocial outcomes for children-contrary to what has been assumed in the discourse about parental migration in Moldova. Copyright © 2014 Elsevier Ltd. All rights reserved.

Peritoneal Dialysate Glucose Load and Systemic Glucose Metabolism in Non-Diabetics: Results from the GLOBAL Fluid Cohort Study

PubMed Central

Chess, James; Do, Jun-Young; Noh, Hyunjin; Lee, Hi-Bahl; Kim, Yong-Lim; Summers, Angela; Williams, Paul Ford; Davison, Sara; Dorval, Marc

2016-01-01

Background and Objectives Glucose control is a significant predictor of mortality in diabetic peritoneal dialysis (PD) patients. During PD, the local toxic effects of intra-peritoneal glucose are well recognized, but despite large amounts of glucose being absorbed, the systemic effects of this in non-diabetic patients are not clear. We sought to clarify whether dialysate glucose has an effect upon systemic glucose metabolism. Methods and Materials We analysed the Global Fluid Study cohort, a prospective, observational cohort study initiated in 2002. A subset of 10 centres from 3 countries with high data quality were selected (368 incident and 272 prevalent non-diabetic patients), with multilevel, multivariable analysis of the reciprocal of random glucose levels, and a stratified-by-centre Cox survival analysis. Results The median follow up was 5.6 and 6.4 years respectively in incident and prevalent patients. On multivariate analysis, serum glucose increased with age (β = -0.007, 95%CI -0.010, -0.004) and decreased with higher serum sodium (β = 0.002, 95%CI 0.0005, 0.003) in incident patients and increased with dialysate glucose (β = -0.0002, 95%CI -0.0004, -0.00006) in prevalent patients. Levels suggested undiagnosed diabetes in 5.4% of prevalent patients. Glucose levels predicted death in unadjusted analyses of both incident and prevalent groups but in an adjusted survival analysis they did not (for random glucose 6–10 compared with <6, Incident group HR 0.92, 95%CI 0.58, 1.46, Prevalent group HR 1.42, 95%CI 0.86, 2.34). Conclusions In prevalent non-diabetic patients, random glucose levels at a diabetic level are under-recognised and increase with dialysate glucose load. Random glucose levels predict mortality in unadjusted analyses, but this association has not been proven in adjusted analyses. PMID:27249020

Glycemic index, glycemic load and invasive breast cancer incidence in postmenopausal women: The PREDIMED study.

PubMed

Castro-Quezada, Itandehui; Sánchez-Villegas, Almudena; Martínez-González, Miguel Á; Salas-Salvadó, Jordi; Corella, Dolores; Estruch, Ramón; Schröder, Helmut; Álvarez-Pérez, Jacqueline; Ruiz-López, María D; Artacho, Reyes; Ros, Emilio; Bulló, Mónica; Sorli, Jose V; Fitó, Montserrat; Ruiz-Gutiérrez, Valentina; Toledo, Estefanía; Buil-Cosiales, Pilar; García Rodríguez, Antonio; Lapetra, José; Pintó, Xavier; Salaverría, Itziar; Tur, Josep A; Romaguera, Dora; Tresserra-Rimbau, Anna; Serra-Majem, Lluís

2016-11-01

The objective of this study was to evaluate the prospective associations between dietary glycemic index (GI) and glycemic load (GL) and the risk for invasive breast cancer incidence in postmenopausal women at high cardiovascular disease (CVD) risk. This study was conducted within the framework of the PREvención con DIeta MEDiterránea (PREDIMED) study, a nutritional intervention trial for primary cardiovascular prevention. We included 4010 women aged between 60 and 80 years who were initially free from breast cancer but at high risk for CVD disease. Dietary information was collected using a validated 137-item food frequency questionnaire. We assigned GI values using the International Tables of GI and GL values. Cases were ascertained through yearly consultation of medical records and through consultation of the National Death Index. Only cases confirmed by results from cytology tests or histological evaluation were included. We estimated multivariable-adjusted hazard ratios for invasive breast cancer risk across tertiles of energy-adjusted dietary GI/GL using Cox regression models. We repeated our analyses using yearly repeated measures of GI/GL intakes. No associations were found between baseline dietary GI/GL and invasive breast cancer incidence. The multivariable hazard ratio and 95% confidence interval (CI) for the top tertile of dietary GI was 1.02 (95% CI: 0.42-2.46) and for dietary GL was 1.00 (95% CI: 0.44-2.30) when compared with the bottom tertile. Repeated-measures analyses yielded similar results. In sensitivity analyses, no significant associations were observed for women with obesity or diabetes. Dietary GI and GL did not appear to be associated with an increased risk for invasive breast cancer in postmenopausal women at high CVD risk.

The pattern of choosing dialysis modality and related mortality outcomes in Korea: a national population-based study

PubMed Central

Kim, Hyung Jong; Park, Jung Tak; Han, Seung Hyeok; Yoo, Tae-Hyun; Park, Hyeong-Cheon; Kang, Shin-Wook; Kim, Kyoung Hoon; Ryu, Dong-Ryeol; Kim, Hyunwook

2017-01-01

Background/Aims Since comorbidities are major determinants of modality choice, and also interact with dialysis modality on mortality outcomes, we examined the pattern of modality choice according to comorbidities and then evaluated how such choices affected mortality in incident dialysis patients. Methods We analyzed 32,280 incident dialysis patients in Korea. Patterns in initial dialysis choice were assessed by multivariate logistic regression analyses. Multivariate Poisson regression analyses were performed to evaluate the effects of interactions between comorbidities and dialysis modality on mortality and to quantify these interactions using the synergy factor. Results Prior histories of myocardial infarction (p = 0.031), diabetes (p = 0.001), and congestive heart failure (p = 0.003) were independent factors favoring the initiation with peritoneal dialysis (PD), but were associated with increased mortality with PD. In contrast, a history of cerebrovascular disease and 1-year increase in age favored initiation with hemodialysis (HD) and were related to a survival benefit with HD (p < 0.001, both). While favoring initiation with HD, having Medical Aid (p = 0.001) and male gender (p = 0.047) were related to increased mortality with HD. Furthermore, although the severity of comorbidities did not inf luence dialysis modality choice, mortality in incident PD patients was significantly higher compared to that in HD patients as the severity of comorbidities increased (p for trend < 0.001). Conclusions Some comorbidities exerted independent effects on initial choice of dialysis modality, but this choice did not always lead to the best results. Further analyses of the pattern of choosing dialysis modality according to baseline comorbid conditions and related consequent mortality outcomes are needed. PMID:28651309

Use of proxy measures in estimating socioeconomic inequalities in malaria prevalence.

PubMed

Somi, Masha F; Butler, James R; Vahid, Farshid; Njau, Joseph D; Kachur, S P; Abdulla, Salim

2008-03-01

To present and compare socioeconomic status (SES) rankings of households using consumption and an asset-based index as two alternative measures of SES; and to compare and evaluate the performance of these two measures in multivariate analyses of the socioeconomic gradient in malaria prevalence. Data for the study come from a survey of 557 households in 25 study villages in Tanzania in 2004. Household SES was determined using consumption and an asset-based index calculated using Principal Components Analysis on a set of household variables. In multivariate analyses of malaria prevalence, we also used two other measures of disease prevalence: parasitaemia and self-report of malaria or fever in the 2 weeks before interview. Household rankings based on the two measures of SES differ substantially. In multivariate analyses, there was a statistically significant negative association between both measures of SES and parasitaemia but not between either measure of SES and self-reported malaria. Age of individual, use of a mosquito net, and wall construction were negatively and significantly associated with parasitaemia, whilst roof construction was positively associated with parasitaemia. Only age remained significant when malaria self-report was used as the measure of disease prevalence. An asset index is an effective alternative to consumption in measuring the socioeconomic gradient in malaria parasitaemia, but self-report may be an unreliable measure of malaria prevalence for this purpose.

Impact of Gender on 30-Day Complications After Primary Total Joint Arthroplasty.

PubMed

Robinson, Jonathan; Shin, John I; Dowdell, James E; Moucha, Calin S; Chen, Darwin D

2017-08-01

Impact of gender on 30-day complications has been investigated in other surgical procedures but has not yet been studied in total hip arthroplasty (THA) or total knee arthroplasty (TKA). Patients who received THA or TKA from 2012 to 2014 were identified in the National Surgical Quality Improvement Program database. Patients were divided into 2 groups based on gender. Bivariate and multivariate analyses were performed to assess associations between gender and patient factors and complications after THA or TKA and to assess whether gender was an independent risk factor. THA patients consisted of 45.1% male and 54.9% female. In a multivariate analysis, female gender was found to be a protective factor for mortality, sepsis, cardiovascular complications, unplanned reintubation, and renal complications and as an independent risk factor for urinary tract infection, blood transfusion, and nonhome discharge after THA. TKA patients consisted of 36.7% male and 62.3% female. Multivariate analysis revealed female gender as a protective factor for sepsis, cardiovascular complications, and renal complications and as an independent risk factor for urinary tract infection, blood transfusion, and nonhome discharge after TKA. There are discrepancies in the THA or TKA complications based on gender, and the multivariate analyses confirmed gender as an independent risk factor for certain complications. Physicians should be mindful of patient's gender for better risk stratification and informed consent. Copyright © 2017 Elsevier Inc. All rights reserved.

Evidence of Mumps Infection Among Children in the Democratic Republic of Congo.

PubMed

Doshi, Reena H; Alfonso, Vivian H; Hoff, Nicole A; Mukadi, Patrick; Gerber, Sue; Bwaka, Ado; Higgins, Stephen G; Mwamba, Guillaume Ngoie; Okitolonda, Emile; Muyembe, Jean-Jacques; Rimoin, Anne W

2017-05-01

Mumps is an acute viral infection and while the infection is usually mild, complications can lead to permanent sequelae including brain damage and deafness. The burden of mumps is currently unknown the Democratic Republic of Congo (DRC), we therefore assessed susceptibility to mumps infection among children 6-59 months of age. In collaboration with the 2013-2014 DRC Demographic and Health Survey, we conducted a serosurvey to assess population immunity to vaccine preventable diseases. Dried blood spot samples were collected from children 6 to 59 months of age and processed at the UCLA-DRC laboratory in Kinshasa, DRC using the Dynex Technologies Multiplier FLEX chemiluminescent immunoassay platform (Dynex multiplex assay, Chantilly, VA). Logistic multivariate analyses were used to determine risk factors for mumps seropositivity. Serologic and survey data were matched for 7195, 6-59 month-old children, among whom 22% were positive and 3% indeterminate for mumps antibodies in weighted analyses. In multivariate analyses, the odds of seropositivity increased with increasing age, female gender, number of children in household, increasing socioeconomic status and province (Kinshasa with the highest odds of positive test result compared with all other provinces). These data suggest that mumps virus is circulating in DRC and risk of exposure increases with age. At present, the introduction of a combined measles-mumps-rubella vaccine remains unlikely, as the capacity to maintain adequate vaccine coverage levels for routine immunization must be improved before additional antigens can be considered for the routine immunization schedule.

Lifestyle Risk Factors Predict Disability and Death in Healthy Aging Adults

PubMed Central

Chakravarty, Eliza F.; Hubert, Helen B.; Krishnan, Eswar; Bruce, Bonnie B.; Lingala, Vijaya B.; Fries, James F.

2011-01-01

Background Associations between modifiable health risk factors during middle age with disability and mortality in later life are critical to maximizing longevity while preserving function. Positive health effects of maintaining normal weight, routine exercise, and non-smoking are known for the short and intermediate term. We studied the effects of these risk factors into advanced age. Methods A cohort of 2,327 college alumnae ≥60 years was followed annually (1986–2005) by questionnaires addressing health risk factors, history, and Health Assessment Questionnaire disability (HAQ-DI). Mortality data were ascertained from the National Death Index. Low, medium, and high risk groups were created based upon the number (0, 1, ≥2) of health risk factors (overweight, smoking, inactivity) at baseline. Disability and mortality for each group were estimated from unadjusted data and regression analyses. Multivariable survival analyses estimated time to disability or death. Results Medium and high-risk groups had higher disability than the low risk group throughout the study (p<0.001). Low-risk subjects had onset of moderate disability delayed 8.3 years compared with high-risk. Mortality rates were higher in the high risk group (384 versus 247 per 10,000 person-years). Multivariable survival analyses showed the number of risk factors to be associated with cumulative disability and increased mortality. Conclusions Seniors with fewer behavioral risk factors during middle age have lower disability and improved survival. These data document that the associations of lifestyle risk factors upon health continue into the ninth decade. PMID:22269623

Cost and utilisation of hospital based delivery care in Empowered Action Group (EAG) states of India.

PubMed

Mohanty, Sanjay K; Srivastava, Akanksha

2013-10-01

Large scale investment in the National Rural Health Mission is expected to increase the utilization and reduce the cost of maternal care in public health centres in India. The objective of this paper is to examine recent trends in the utilization and cost of hospital based delivery care in the Empowered Action Group (EAG) states of India. The unit data from the District Level Household Survey 3, 2007-2008 is used in the analyses. The coverage and the cost of hospital based delivery at constant price is analyzed for five consecutive years preceding the survey. Descriptive and multivariate analyses are used to understand the socio-economic differentials in cost and utilization of delivery care. During 2004-2008, the utilization of delivery care from public health centres has increased in all the eight EAG states. Adjusting for inflation, the household cost of delivery care has declined for the poor, less educated and in public health centres in the EAG states. The cost of delivery care in private health centres has not shown any significant changes across the states. Results of the multivariate analyses suggest that time, state, place of residence, economic status; educational attainment and delivery characteristics of mother are significant predictors of hospital based delivery care in India. The study demonstrates the utility of public spending on health care and provides a thrust to the ongoing debate on universal health coverage in India.

Multivariate analyses of crater parameters and the classification of craters

NASA Technical Reports Server (NTRS)

Siegal, B. S.; Griffiths, J. C.

1974-01-01

Multivariate analyses were performed on certain linear dimensions of six genetic types of craters. A total of 320 craters, consisting of laboratory fluidization craters, craters formed by chemical and nuclear explosives, terrestrial maars and other volcanic craters, and terrestrial meteorite impact craters, authenticated and probable, were analyzed in the first data set in terms of their mean rim crest diameter, mean interior relief, rim height, and mean exterior rim width. The second data set contained an additional 91 terrestrial craters of which 19 were of experimental percussive impact and 28 of volcanic collapse origin, and which was analyzed in terms of mean rim crest diameter, mean interior relief, and rim height. Principal component analyses were performed on the six genetic types of craters. Ninety per cent of the variation in the variables can be accounted for by two components. Ninety-nine per cent of the variation in the craters formed by chemical and nuclear explosives is explained by the first component alone.

Hepatectomy As A First Choice Treatment For Liver Metastasis From Gastric Cancer: A Single Center Experience.

PubMed

Sakamoto, Hirohiko; Amikura, Katsumi; Tanaka, Yoichi; Kawashima, Yoshiyuki

2014-05-01

Indication of hepatectomy for liver metastases from gastric cancer (LMGC) is still controversial despite many papers favoring surgery. The aim of this study is to claim that we should accept hepatectomy as first choice treatment for LMGC. It is important to have a consensus on this matter for surgeons to treat LMGC properly. Fifty three patients undergoing hepatectomy for LMGC from 1990 through 2010 were retrospectively analysed for survival and prognostic factors. Analyses were made on size, multiplicity, synchronicity and positive surgical margin as liver metastasis factors. Serosal invasion, node metastasis, histological differentiation and UICC stage were analysed as primary site factors. Multivariate analysis was performed for those positive for univariate analysis. Cumulative 5 year survival rate was 27%. Multiplicity, positive margin and node metastasis (N > 2) yielded significant difference on univariate analysis. On multivariate analysis multiplicity and node metastasis (N > 2) were significant. Hepatectomy for LMGC is potentially curative and should be regarded as first choice. Solitary and N < 3 are good prognostic factors.

Social support network characteristics and sexual risk taking among a racially/ethnically diverse sample of young, urban men who have sex with men.

PubMed

Kapadia, F; Siconolfi, D E; Barton, S; Olivieri, B; Lombardo, L; Halkitis, P N

2013-06-01

Associations between social support network characteristics and sexual risk among racially/ethnically diverse young men who have sex with men (YMSM) were examined using egocentric network data from a prospective cohort study of YMSM (n = 501) recruited in New York City. Bivariate and multivariable logistic regression analyses examined associations between social support network characteristics and sexual risk taking behaviors in Black, Hispanic/Latino, and White YMSM. Bivariate analyses indicated key differences in network size, composition, communication frequency and average relationship duration by race/ethnicity. In multivariable analyses, controlling for individual level sociodemographic, psychosocial and relationship factors, having a sexual partner in one's social support network was associated with unprotected sexual behavior for both Hispanic/Latino (AOR = 3.90) and White YMSM (AOR = 4.93). Further examination of key network characteristics across racial/ethnic groups are warranted in order to better understand the extant mechanisms for provision of HIV prevention programming to racially/ethnically diverse YMSM at risk for HIV.

Multi-variant study of obesity risk genes in African Americans: The Jackson Heart Study.

PubMed

Liu, Shijian; Wilson, James G; Jiang, Fan; Griswold, Michael; Correa, Adolfo; Mei, Hao

2016-11-30

Genome-wide association study (GWAS) has been successful in identifying obesity risk genes by single-variant association analysis. For this study, we designed steps of analysis strategy and aimed to identify multi-variant effects on obesity risk among candidate genes. Our analyses were focused on 2137 African American participants with body mass index measured in the Jackson Heart Study and 657 common single nucleotide polymorphisms (SNPs) genotyped at 8 GWAS-identified obesity risk genes. Single-variant association test showed that no SNPs reached significance after multiple testing adjustment. The following gene-gene interaction analysis, which was focused on SNPs with unadjusted p-value<0.10, identified 6 significant multi-variant associations. Logistic regression showed that SNPs in these associations did not have significant linear interactions; examination of genetic risk score evidenced that 4 multi-variant associations had significant additive effects of risk SNPs; and haplotype association test presented that all multi-variant associations contained one or several combinations of particular alleles or haplotypes, associated with increased obesity risk. Our study evidenced that obesity risk genes generated multi-variant effects, which can be additive or non-linear interactions, and multi-variant study is an important supplement to existing GWAS for understanding genetic effects of obesity risk genes. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing admixture by multivariate analyses of phenotypic differentiation in the Algerian goat livestock.

PubMed

Ouchene-Khelifi, Nadjet-Amina; Ouchene, Nassim; Maftah, Abderrahman; Da Silva, Anne Blondeau; Lafri, Mohamed

2015-10-01

In Algeria, goat research has been largely neglected, in spite of the economic importance of this domestic species for rural livelihoods. Goat farming is traditional and cross-breeding practices are current. The phenotypic variability of the four main native breeds (Arabia, Makatia, M'zabite and Kabyle), and of two exotic breeds (Alpine and Saanen), was investigated for the first time, using multivariate discriminant analysis. A total of 892 females were sampled in a large area, including the cradle of the native breeds, and phenotyped with 23 quantitative measures and 10 qualitative traits. Our results suggested that cross-breeding practices have ever led to critical consequences, particularly for Makatia and M'zabite. The information reported in this study has to be carefully considered in order to establish governmental plan able to prevent the genetic dilution of the Algerian goat livestock.

Work and retirement among a cohort of older men in the United States, 1966-1983.

PubMed

Hayward, M D; Grady, W R

1990-08-01

Multivariate increment-decrement working life tables are estimated for a cohort of older men in the United States for the period 1966-1983. The approach taken allows multiple processes to be simultaneously incorporated into a single model, resulting in a more realistic portrayal of a cohort's late-life labor force behavior. In addition, because the life table model is developed from multivariate hazard equations, we identify the effects of sociodemographic characteristics on the potentially complex process by which the labor force career is ended. In contrast to the assumed homogeneity of previous working life table analyses, the present study shows marked differences in labor force mobility and working and nonworking life expectancy according to occupation, class of worker, education, race, and marital status. We briefly discuss the implications of these findings for inequities of access to retirement, private and public pension consumption, and future changes in the retirement process.

Compassion Fatigue and Psychological Distress Among Social Workers: A Validation Study

PubMed Central

Adams, Richard E.; Boscarino, Joseph A.; Figley, Charles R.

2009-01-01

Few studies have focused on caring professionals and their emotional exhaustion from working with traumatized clients, referred to as compassion fatigue (CF). The present study had 2 goals: (a) to assess the psychometric properties of a CF scale, and (b) to examine the scale's predictive validity in a multivariate model. The data came from a survey of social workers living in New York City following the September 11, 2001, terrorist attacks on the World Trade Center. Factor analyses indicated that the CF scale measured multiple dimensions. After overlapping items were eliminated, the scale measured 2 key underlying dimensions—secondary trauma and job burnout. In a multivariate model, these dimensions were related to psychological distress, even after other risk factors were controlled. The authors discuss the results in light of increasing the ability of professional caregivers to meet the emotional needs of their clients within a stressful environment without experiencing CF. PMID:16569133

Analysis of fatty acid composition of sea cucumber Apostichopus japonicus using multivariate statistics

NASA Astrophysics Data System (ADS)

Xu, Qinzeng; Gao, Fei; Xu, Qiang; Yang, Hongsheng

2014-11-01

Fatty acids (FAs) provide energy and also can be used to trace trophic relationships among organisms. Sea cucumber Apostichopus japonicus goes into a state of aestivation during warm summer months. We examined fatty acid profiles in aestivated and non-aestivated A. japonicus using multivariate analyses (PERMANOVA, MDS, ANOSIM, and SIMPER). The results indicate that the fatty acid profiles of aestivated and non-aestivated sea cucumbers differed significantly. The FAs that were produced by bacteria and brown kelp contributed the most to the differences in the fatty acid composition of aestivated and nonaestivated sea cucumbers. Aestivated sea cucumbers may synthesize FAs from heterotrophic bacteria during early aestivation, and long chain FAs such as eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) that produced from intestinal degradation, are digested during deep aestivation. Specific changes in the fatty acid composition of A. japonicus during aestivation needs more detailed study in the future.

Shear wave elastography predicts hepatocellular carcinoma risk in hepatitis C patients after sustained virological response.

PubMed

Hamada, Koichi; Saitoh, Satoshi; Nishino, Noriyuki; Fukushima, Daizo; Horikawa, Yoshinori; Nishida, Shinya; Honda, Michitaka

2018-01-01

To evaluate the relationship between fibrosis and HCC after sustained virological response (SVR) to treatment for chronic hepatitis C (HCV). This single-center study retrospectively evaluated 196 patients who achieved SVR after HCV infection. The associations of risk factors with HCC development after HCV eradication were evaluated using univariate and multivariate Cox proportional hazards regression models. Among the 196 patients, 8 patients (4.1%) developed HCC after SVR during a median follow-up of 26 months. Multivariate analyses revealed that HCC development was independently associated with age of ≥75 years (risk ratio [RR] = 35.16), α- fetoprotein levels of ≥6 ng/mL (RR = 40.30), and SWE results of ≥11 kPa (RR = 28.71). Our findings indicate that SWE may facilitate HCC surveillance after SVR and the identification of patients who have an increased risk of HCC after HCV clearance.

Specific prognostic factors for secondary pancreatic infection in severe acute pancreatitis.

PubMed

Armengol-Carrasco, M; Oller, B; Escudero, L E; Roca, J; Gener, J; Rodríguez, N; del Moral, P; Moreno, P

1999-01-01

The aim of the present study was to investigate whether there are specific prognostic factors to predict the development of secondary pancreatic infection (SPI) in severe acute pancreatitis in order to perform a computed tomography-fine needle aspiration with bacteriological sampling at the right moment and confirm the diagnosis. Twenty-five clinical and laboratory parameters were determined sequentially in 150 patients with severe acute pancreatitis (SAP) and univariate, and multivariate regression analyses were done looking for correlation with the development of SPI. Only APACHE II score and C-reactive protein levels were related to the development of SPI in the multivariate analysis. A regression equation was designed using these two parameters, and empiric cut-off points defined the subgroup of patients at high risk of developing secondary pancreatic infection. The results showed that it is possible to predict SPI during SAP allowing bacteriological confirmation and early treatment of this severe condition.

Compulsive buying: Earlier illicit drug use, impulse buying, depression, and adult ADHD symptoms.

PubMed

Brook, Judith S; Zhang, Chenshu; Brook, David W; Leukefeld, Carl G

2015-08-30

This longitudinal study examined the association between psychosocial antecedents, including illicit drug use, and adult compulsive buying (CB) across a 29-year time period from mean age 14 to mean age 43. Participants originally came from a community-based random sample of residents in two upstate New York counties. Multivariate linear regression analysis was used to study the relationship between the participant's earlier psychosocial antecedents and adult CB in the fifth decade of life. The results of the multivariate linear regression analyses showed that gender (female), earlier adult impulse buying (IB), depressive mood, illicit drug use, and concurrent ADHD symptoms were all significantly associated with adult CB at mean age 43. It is important that clinicians treating CB in adults should consider the role of drug use, symptoms of ADHD, IB, depression, and family factors in CB. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Compulsive Buying: Earlier Illicit Drug Use, Impulse Buying, Depression, and Adult ADHD Symptoms

PubMed Central

Brook, Judith S.; Zhang, Chenshu; Brook, David W.; Leukefeld, Carl G.

2015-01-01

This longitudinal study examined the association between psychosocial antecedents, including illicit drug use, and adult compulsive buying (CB) across a 29-year time period from mean age 14 to mean age 43. Participants originally came from a community-based random sample of residents in two upstate New York counties. Multivariate linear regression analysis was used to study the relationship between the participant’s earlier psychosocial antecedents and adult CB in the fifth decade of life. The results of the multivariate linear regression analyses showed that gender (female), earlier adult impulse buying (IB), depressive mood, illicit drug use, and concurrent ADHD symptoms were all significantly associated with adult CB at mean age 43. It is important that clinicians treating CB in adults should consider the role of drug use, symptoms of ADHD, IB, depression, and family factors in CB. PMID:26165963

Written violence policies and risk of physical assault against Minnesota educators.

PubMed

Feda, Denise M; Gerberich, Susan G; Ryan, Andrew D; Nachreiner, Nancy M; McGovern, Patricia M

2010-12-01

Few research studies on school violence policies use quantitative methods to evaluate the impact of policies on workplace violence. This study analyzed nine different written violence policies and their impact on work-related physical assault in educational settings. Data were from the Minnesota Educators' Study. This large, nested case control study included cases (n=372) who reported physical assaults within the last year, and controls (n=1116) who did not. Multivariate logistic regression analyses, using directed acyclic graphs, estimated risk of assault. Results of the adjusted multivariate model suggested decreased risks of physical assault were associated with the presence of policies regarding how to report sexual harassment, verbal abuse, and threat (OR 0.53; 95 per cent CI: 0.30-0.95); assurance of confidential reporting of events (OR 0.67; 95 per cent CI: 0.44-1.04); and zero tolerance for violence (OR 0.70; 95 per cent CI: 0.47-1.04).

The Impact of Work Ability on Work Motivation and Health: A Longitudinal Study Based on Older Employees.

PubMed

Feißel, Annemarie; Swart, Enno; March, Stefanie

2018-05-01

Work participation is determined by work motivation and work ability with health as a significant component. Within the lidA-study, we explore the impact of work ability on work motivation and health with consideration of further influencing factors. Four thousand one hundred nine older employees were interviewed two times (t0 = 2011, t1 = 2014). Two multivariate analyses were performed regarding the influence of work ability on work motivation (Model 1) and health (Model 2). Within the multivariate analysis, of all the influencing factors, work ability has the strongest effect on work motivation (F = 37.761) and health (F = 76.402). It appears as a decisive determinant for both dimensions. Regarding the results, it is useful to focus on the work ability of older employees in order to maintain and boost their work motivation and health.

A queer day in Canada: examining Canadian high school students' experiences with school-based homophobia in two large-scale studies.

PubMed

Peter, Tracey; Taylor, Catherine; Chamberland, Line

2015-01-01

The goal of the study is to examine how location (nationally, compared to Canadian regions) is related to indicators of a hostile school environment for sexual minority youth, particularly when physical abuse is used as the outcome variable. Data representing 5,766 Canadian students were analyzed using bivariate and multivariate techniques. Results from the multivariate analyses showed that non-physical abuse was the most significant predictor of homophobically based physical abuse, for both LGBQ and non-LGBQ students. Findings reiterate the importance of considering the progression of harmful events as an escalation of violence as well as the need to view homophobic bullying as having a significant impact on all students. Finally, while the presence of homophobia is prevalent across all Canadian regions, there are, nevertheless, many regional differences, which could be used to inform region-specific action plans.

A Multivariate Granger Causality Concept towards Full Brain Functional Connectivity.

PubMed

Schmidt, Christoph; Pester, Britta; Schmid-Hertel, Nicole; Witte, Herbert; Wismüller, Axel; Leistritz, Lutz

2016-01-01

Detecting changes of spatially high-resolution functional connectivity patterns in the brain is crucial for improving the fundamental understanding of brain function in both health and disease, yet still poses one of the biggest challenges in computational neuroscience. Currently, classical multivariate Granger Causality analyses of directed interactions between single process components in coupled systems are commonly restricted to spatially low- dimensional data, which requires a pre-selection or aggregation of time series as a preprocessing step. In this paper we propose a new fully multivariate Granger Causality approach with embedded dimension reduction that makes it possible to obtain a representation of functional connectivity for spatially high-dimensional data. The resulting functional connectivity networks may consist of several thousand vertices and thus contain more detailed information compared to connectivity networks obtained from approaches based on particular regions of interest. Our large scale Granger Causality approach is applied to synthetic and resting state fMRI data with a focus on how well network community structure, which represents a functional segmentation of the network, is preserved. It is demonstrated that a number of different community detection algorithms, which utilize a variety of algorithmic strategies and exploit topological features differently, reveal meaningful information on the underlying network module structure.

A model-based approach to wildland fire reconstruction using sediment charcoal records

USGS Publications Warehouse

Itter, Malcolm S.; Finley, Andrew O.; Hooten, Mevin B.; Higuera, Philip E.; Marlon, Jennifer R.; Kelly, Ryan; McLachlan, Jason S.

2017-01-01

Lake sediment charcoal records are used in paleoecological analyses to reconstruct fire history, including the identification of past wildland fires. One challenge of applying sediment charcoal records to infer fire history is the separation of charcoal associated with local fire occurrence and charcoal originating from regional fire activity. Despite a variety of methods to identify local fires from sediment charcoal records, an integrated statistical framework for fire reconstruction is lacking. We develop a Bayesian point process model to estimate the probability of fire associated with charcoal counts from individual-lake sediments and estimate mean fire return intervals. A multivariate extension of the model combines records from multiple lakes to reduce uncertainty in local fire identification and estimate a regional mean fire return interval. The univariate and multivariate models are applied to 13 lakes in the Yukon Flats region of Alaska. Both models resulted in similar mean fire return intervals (100–350 years) with reduced uncertainty under the multivariate model due to improved estimation of regional charcoal deposition. The point process model offers an integrated statistical framework for paleofire reconstruction and extends existing methods to infer regional fire history from multiple lake records with uncertainty following directly from posterior distributions.

Membrane Introduction Mass Spectrometry Combined with an Orthogonal Partial-Least Squares Calibration Model for Mixture Analysis.

PubMed

Li, Min; Zhang, Lu; Yao, Xiaolong; Jiang, Xingyu

2017-01-01

The emerging membrane introduction mass spectrometry technique has been successfully used to detect benzene, toluene, ethyl benzene and xylene (BTEX), while overlapped spectra have unfortunately hindered its further application to the analysis of mixtures. Multivariate calibration, an efficient method to analyze mixtures, has been widely applied. In this paper, we compared univariate and multivariate analyses for quantification of the individual components of mixture samples. The results showed that the univariate analysis creates poor models with regression coefficients of 0.912, 0.867, 0.440 and 0.351 for BTEX, respectively. For multivariate analysis, a comparison to the partial-least squares (PLS) model shows that the orthogonal partial-least squares (OPLS) regression exhibits an optimal performance with regression coefficients of 0.995, 0.999, 0.980 and 0.976, favorable calibration parameters (RMSEC and RMSECV) and a favorable validation parameter (RMSEP). Furthermore, the OPLS exhibits a good recovery of 73.86 - 122.20% and relative standard deviation (RSD) of the repeatability of 1.14 - 4.87%. Thus, MIMS coupled with the OPLS regression provides an optimal approach for a quantitative BTEX mixture analysis in monitoring and predicting water pollution.

Gene-set and multivariate genome-wide association analysis of oppositional defiant behavior subtypes in attention-deficit/hyperactivity disorder.

PubMed

Aebi, Marcel; van Donkelaar, Marjolein M J; Poelmans, Geert; Buitelaar, Jan K; Sonuga-Barke, Edmund J S; Stringaris, Argyris; Consortium, Image; Faraone, Stephen V; Franke, Barbara; Steinhausen, Hans-Christoph; van Hulzen, Kimm J E

2016-07-01

Oppositional defiant disorder (ODD) is a frequent psychiatric disorder seen in children and adolescents with attention-deficit-hyperactivity disorder (ADHD). ODD is also a common antecedent to both affective disorders and aggressive behaviors. Although the heritability of ODD has been estimated to be around 0.60, there has been little research into the molecular genetics of ODD. The present study examined the association of irritable and defiant/vindictive dimensions and categorical subtypes of ODD (based on latent class analyses) with previously described specific polymorphisms (DRD4 exon3 VNTR, 5-HTTLPR, and seven OXTR SNPs) as well as with dopamine, serotonin, and oxytocin genes and pathways in a clinical sample of children and adolescents with ADHD. In addition, we performed a multivariate genome-wide association study (GWAS) of the aforementioned ODD dimensions and subtypes. Apart from adjusting the analyses for age and sex, we controlled for "parental ability to cope with disruptive behavior." None of the hypothesis-driven analyses revealed a significant association with ODD dimensions and subtypes. Inadequate parenting behavior was significantly associated with all ODD dimensions and subtypes, most strongly with defiant/vindictive behaviors. In addition, the GWAS did not result in genome-wide significant findings but bioinformatics and literature analyses revealed that the proteins encoded by 28 of the 53 top-ranked genes functionally interact in a molecular landscape centered around Beta-catenin signaling and involved in the regulation of neurite outgrowth. Our findings provide new insights into the molecular basis of ODD and inform future genetic studies of oppositional behavior. © 2015 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. © 2015 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Susceptible genes of restless legs syndrome in migraine.

PubMed

Fuh, Jong-Ling; Chung, Ming-Yi; Yao, Shu-Chih; Chen, Ping-Kun; Liao, Yi-Chu; Hsu, Chia-Lin; Wang, Po-Jen; Wang, Yen-Feng; Chen, Shih-Pin; Fann, Cathy S-J; Kao, Lung-Sen; Wang, Shuu-Jiun

2016-10-01

Objective Several genetic variants have been found to increase the risk of restless legs syndrome (RLS). The aim of the present study was to determine if these genetic variants were also associated with the comorbidity of RLS and migraine in patients. Methods Thirteen single-nucleotide polymorphisms (SNPs) at six RLS risk loci ( MEIS1, BTBD9, MAP2K5, PTPRD, TOX3, and an intergenic region on chromosome 2p14) were genotyped in 211 migraine patients with RLS and 781 migraine patients without RLS. Association analyses were performed for the overall cohort, as well as for the subgroups of patients who experienced migraines with and without aura and episodic migraines (EMs) vs. chronic migraines (CMs). In order to verify which genetic markers were potentially related to the incidence of RLS in migraine patients, multivariate regression analyses were also performed. Results Among the six tested loci, only MEIS1 was significantly associated with RLS. The most significant SNP of MEIS1, rs2300478, increased the risk of RLS by 1.42-fold in the overall cohort ( p = 0.0047). In the subgroup analyses, MEIS1 augmented the risk of RLS only in the patients who experienced EMs (odds ratio (OR) = 1.99, p = 0.0004) and not those experiencing CMs. Multivariate regression analyses further showed that rs2300478 in MEIS1 (OR = 1.39, p = 0.018), a CM diagnosis (OR = 1.52, p = 0.022), and depression (OR = 1.86, p = 0.005) were independent predictors of RLS in migraine. Conclusions MEIS1 variants were associated with an increased risk of RLS in migraine patients. It is possible that an imbalance in iron homeostasis and the dopaminergic system may represent a link between RLS incidence and migraines.

Hydronephrosis in patients with cervical cancer: an assessment of morbidity and survival

PubMed Central

Patel, Krishna; Foster, Nathan R.; Kumar, Amanika; Grudem, Megan; Longenbach, Sherri; Bakkum-Gamez, Jamie; Haddock, Michael; Dowdy, Sean; Jatoi, Aminah

2015-01-01

Purpose Hydronephrosis is a frequently observed but understudied complication in patients with cervical cancer. To better characterize hydronephrosis in cervical cancer patients, the current study sought (1) to describe hydronephrosis-associated morbidity and (2) to analyze the prognostic effect of hydronephrosis in patients with a broad range of cancer stages over time. Methods The Mayo Clinic Tumor Registry was interrogated for all invasive cervical cancer patients seen at the Mayo Clinic from 2008 through 2013 in Rochester, Minnesota; these patients’ medical records were then reviewed in detail. Results Two hundred seventy-nine cervical cancer patients with a median age of 49 years and a range of cancer stages were included. Sixty-five patients (23 %) were diagnosed with hydronephrosis at some point during their disease course. In univariate analyses, hydronephrosis was associated with advanced cancer stage (p<0.0001), squamous histology (p=0.0079), and nonsurgical cancer treatment (p=0.0039). In multivariate analyses, stage and tumor histology were associated with hydronephrosis. All but one patient underwent stent placement or urinary diversion; hydronephrosis-related morbidity included pain, urinary tract infections, nausea and vomiting, renal failure, and urinary tract bleeding. In landmark univariate survival analyses, hydronephrosis was associated with worse survival at all time points. In landmark multivariate analyses (adjusted for patient age, stage, cancer treatment, and tumor histology), hydronephrosis was associated with a trend toward worse survival over time (hazard ratios ranged from 1.47 to 4.69). Conclusion Hydronephrosis in cervical cancer patients is associated with notable morbidity. It is also associated with trends toward worse survival—even if it occurs after the original cancer diagnosis. PMID:25339620

Epidemiology of antibiotic-resistant wound infections from six countries in Africa

PubMed Central

Bebell, Lisa M; Meney, Carron; Valeri, Linda

2017-01-01

Introduction Little is known about the antimicrobial susceptibility of common bacteria responsible for wound infections from many countries in sub-Saharan Africa. Methods We performed a retrospective review of microbial isolates collected based on clinical suspicion of wound infection between 2004 and 2016 from Mercy Ships, a non-governmental organisation operating a single mobile surgical unit in Benin, Congo, Liberia, Madagascar, Sierra Leone and Togo. Antimicrobial resistant organisms of interest were defined as methicillin-resistant Staphylococcus aureus (MRSA) or Enterobacteriaceae resistant to third-generation cephalosporins. Generalised mixed-effects models accounting for repeated isolates in a patient, potential clustering by case mix for each field service, age, gender and country were used to test the hypothesis that rates of antimicrobial resistance differed between countries. Results 3145 isolates from repeated field services in six countries were reviewed. In univariate analyses, the highest proportion of MRSA was found in Benin (34.6%) and Congo (31.9%), while the lowest proportion was found in Togo (14.3%) and Madagascar (14.5%); country remained a significant predictor in multivariate analyses (P=0.002). In univariate analyses, the highest proportion of third-generation cephalosporin-resistant Enterobacteriaceae was found in Benin (35.8%) and lowest in Togo (14.3%) and Madagascar (16.3%). Country remained a significant predictor for antimicrobial-resistant isolates in multivariate analyses (P=0.009). Conclusion A significant proportion of isolates from wound cultures were resistant to first-line antimicrobials in each country. Though antimicrobial resistance isolates were not verified in a reference laboratory and these data may not be representative of all regions of the countries studied, differences in the proportion of antimicrobial-resistant isolates and resistance profiles between countries suggest site-specific surveillance should be a priority and local antimicrobial resistance profiles should be used to guide empiric antibiotic selection. PMID:29588863

Gene‐set and multivariate genome‐wide association analysis of oppositional defiant behavior subtypes in attention‐deficit/hyperactivity disorder

PubMed Central

van Donkelaar, Marjolein M. J.; Poelmans, Geert; Buitelaar, Jan K.; Sonuga‐Barke, Edmund J. S.; Stringaris, Argyris; consortium, IMAGE; Faraone, Stephen V.; Franke, Barbara; Steinhausen, Hans‐Christoph; van Hulzen, Kimm J. E.

2015-01-01

Oppositional defiant disorder (ODD) is a frequent psychiatric disorder seen in children and adolescents with attention‐deficit‐hyperactivity disorder (ADHD). ODD is also a common antecedent to both affective disorders and aggressive behaviors. Although the heritability of ODD has been estimated to be around 0.60, there has been little research into the molecular genetics of ODD. The present study examined the association of irritable and defiant/vindictive dimensions and categorical subtypes of ODD (based on latent class analyses) with previously described specific polymorphisms (DRD4 exon3 VNTR, 5‐HTTLPR, and seven OXTR SNPs) as well as with dopamine, serotonin, and oxytocin genes and pathways in a clinical sample of children and adolescents with ADHD. In addition, we performed a multivariate genome‐wide association study (GWAS) of the aforementioned ODD dimensions and subtypes. Apart from adjusting the analyses for age and sex, we controlled for “parental ability to cope with disruptive behavior.” None of the hypothesis‐driven analyses revealed a significant association with ODD dimensions and subtypes. Inadequate parenting behavior was significantly associated with all ODD dimensions and subtypes, most strongly with defiant/vindictive behaviors. In addition, the GWAS did not result in genome‐wide significant findings but bioinformatics and literature analyses revealed that the proteins encoded by 28 of the 53 top‐ranked genes functionally interact in a molecular landscape centered around Beta‐catenin signaling and involved in the regulation of neurite outgrowth. Our findings provide new insights into the molecular basis of ODD and inform future genetic studies of oppositional behavior. © 2015 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc. PMID:26184070

Effects of unplanned treatment interruptions on HIV treatment failure - results from TAHOD.

PubMed

Jiamsakul, Awachana; Kerr, Stephen J; Ng, Oon Tek; Lee, Man Po; Chaiwarith, Romanee; Yunihastuti, Evy; Van Nguyen, Kinh; Pham, Thuy Thanh; Kiertiburanakul, Sasisopin; Ditangco, Rossana; Saphonn, Vonthanak; Sim, Benedict L H; Merati, Tuti Parwati; Wong, Wingwai; Kantipong, Pacharee; Zhang, Fujie; Choi, Jun Yong; Pujari, Sanjay; Kamarulzaman, Adeeba; Oka, Shinichi; Mustafa, Mahiran; Ratanasuwan, Winai; Petersen, Boondarika; Law, Matthew; Kumarasamy, Nagalingeswaran

2016-05-01

Treatment interruptions (TIs) of combination antiretroviral therapy (cART) are known to lead to unfavourable treatment outcomes but do still occur in resource-limited settings. We investigated the effects of TI associated with adverse events (AEs) and non-AE-related reasons, including their durations, on treatment failure after cART resumption in HIV-infected individuals in Asia. Patients initiating cART between 2006 and 2013 were included. TI was defined as stopping cART for >1 day. Treatment failure was defined as confirmed virological, immunological or clinical failure. Time to treatment failure during cART was analysed using Cox regression, not including periods off treatment. Covariables with P < 0.10 in univariable analyses were included in multivariable analyses, where P < 0.05 was considered statistically significant. Of 4549 patients from 13 countries in Asia, 3176 (69.8%) were male and the median age was 34 years. A total of 111 (2.4%) had TIs due to AEs and 135 (3.0%) had TIs for other reasons. Median interruption times were 22 days for AE and 148 days for non-AE TIs. In multivariable analyses, interruptions >30 days were associated with failure (31-180 days HR = 2.66, 95%CI (1.70-4.16); 181-365 days HR = 6.22, 95%CI (3.26-11.86); and >365 days HR = 9.10, 95% CI (4.27-19.38), all P < 0.001, compared to 0-14 days). Reasons for previous TI were not statistically significant (P = 0.158). Duration of interruptions of more than 30 days was the key factor associated with large increases in subsequent risk of treatment failure. If TI is unavoidable, its duration should be minimised to reduce the risk of failure after treatment resumption. © 2016 John Wiley & Sons Ltd.

Measurement issues in research on social support and health.

PubMed Central

Dean, K; Holst, E; Kreiner, S; Schoenborn, C; Wilson, R

1994-01-01

STUDY OBJECTIVE--The aims were: (1) to identify methodological problems that may explain the inconsistencies and contradictions in the research evidence on social support and health, and (2) to validate a frequently used measure of social support in order to determine whether or not it could be used in multivariate analyses of population data in research on social support and health. DESIGN AND METHODS--Secondary analysis of data collected in a cross sectional survey of a multistage cluster sample of the population of the United States, designed to study relationships in behavioural, social support and health variables. Statistical models based on item response theory and graph theory were used to validate the measure of social support to be used in subsequent analyses. PARTICIPANTS--Data on 1755 men and women aged 20 to 64 years were available for the scale validation. RESULTS--Massive evidence of item bias was found for all items of a group membership subscale. The most serious problems were found in relationship to an item measuring membership in work related groups. Using that item in the social network scale in multivariate analyses would distort findings on the statistical effects of education, employment status, and household income. Evidence of item bias was also found for a sociability subscale. When marital status was included to create what is called an intimate contacts subscale, the confounding grew worse. CONCLUSIONS--The composite measure of social network is not valid and would seriously distort the findings of analyses attempting to study relationships between the index and other variables. The findings show that valid measurement is a methodological issue that must be addressed in scientific research on population health. PMID:8189179

Assessment of metals bioavailability to vegetables under field conditions using DGT, single extractions and multivariate statistics

PubMed Central

2012-01-01

Background The metals bioavailability in soils is commonly assessed by chemical extractions; however a generally accepted method is not yet established. In this study, the effectiveness of Diffusive Gradients in Thin-films (DGT) technique and single extractions in the assessment of metals bioaccumulation in vegetables, and the influence of soil parameters on phytoavailability were evaluated using multivariate statistics. Soil and plants grown in vegetable gardens from mining-affected rural areas, NW Romania, were collected and analysed. Results Pseudo-total metal content of Cu, Zn and Cd in soil ranged between 17.3-146 mg kg-1, 141–833 mg kg-1 and 0.15-2.05 mg kg-1, respectively, showing enriched contents of these elements. High degrees of metals extractability in 1M HCl and even in 1M NH4Cl were observed. Despite the relatively high total metal concentrations in soil, those found in vegetables were comparable to values typically reported for agricultural crops, probably due to the low concentrations of metals in soil solution (Csoln) and low effective concentrations (CE), assessed by DGT technique. Among the analysed vegetables, the highest metal concentrations were found in carrots roots. By applying multivariate statistics, it was found that CE, Csoln and extraction in 1M NH4Cl, were better predictors for metals bioavailability than the acid extractions applied in this study. Copper transfer to vegetables was strongly influenced by soil organic carbon (OC) and cation exchange capacity (CEC), while pH had a higher influence on Cd transfer from soil to plants. Conclusions The results showed that DGT can be used for general evaluation of the risks associated to soil contamination with Cu, Zn and Cd in field conditions. Although quantitative information on metals transfer from soil to vegetables was not observed. PMID:23079133

Using Statistical Process Control for detecting anomalies in multivariate spatiotemporal Earth Observations

NASA Astrophysics Data System (ADS)

Flach, Milan; Mahecha, Miguel; Gans, Fabian; Rodner, Erik; Bodesheim, Paul; Guanche-Garcia, Yanira; Brenning, Alexander; Denzler, Joachim; Reichstein, Markus

2016-04-01

The number of available Earth observations (EOs) is currently substantially increasing. Detecting anomalous patterns in these multivariate time series is an important step in identifying changes in the underlying dynamical system. Likewise, data quality issues might result in anomalous multivariate data constellations and have to be identified before corrupting subsequent analyses. In industrial application a common strategy is to monitor production chains with several sensors coupled to some statistical process control (SPC) algorithm. The basic idea is to raise an alarm when these sensor data depict some anomalous pattern according to the SPC, i.e. the production chain is considered 'out of control'. In fact, the industrial applications are conceptually similar to the on-line monitoring of EOs. However, algorithms used in the context of SPC or process monitoring are rarely considered for supervising multivariate spatio-temporal Earth observations. The objective of this study is to exploit the potential and transferability of SPC concepts to Earth system applications. We compare a range of different algorithms typically applied by SPC systems and evaluate their capability to detect e.g. known extreme events in land surface processes. Specifically two main issues are addressed: (1) identifying the most suitable combination of data pre-processing and detection algorithm for a specific type of event and (2) analyzing the limits of the individual approaches with respect to the magnitude, spatio-temporal size of the event as well as the data's signal to noise ratio. Extensive artificial data sets that represent the typical properties of Earth observations are used in this study. Our results show that the majority of the algorithms used can be considered for the detection of multivariate spatiotemporal events and directly transferred to real Earth observation data as currently assembled in different projects at the European scale, e.g. http://baci-h2020.eu/index.php/ and http://earthsystemdatacube.net/. Known anomalies such as the Russian heatwave are detected as well as anomalies which are not detectable with univariate methods.

Quality by design case study: an integrated multivariate approach to drug product and process development.

PubMed

Huang, Jun; Kaul, Goldi; Cai, Chunsheng; Chatlapalli, Ramarao; Hernandez-Abad, Pedro; Ghosh, Krishnendu; Nagi, Arwinder

2009-12-01

To facilitate an in-depth process understanding, and offer opportunities for developing control strategies to ensure product quality, a combination of experimental design, optimization and multivariate techniques was integrated into the process development of a drug product. A process DOE was used to evaluate effects of the design factors on manufacturability and final product CQAs, and establish design space to ensure desired CQAs. Two types of analyses were performed to extract maximal information, DOE effect & response surface analysis and multivariate analysis (PCA and PLS). The DOE effect analysis was used to evaluate the interactions and effects of three design factors (water amount, wet massing time and lubrication time), on response variables (blend flow, compressibility and tablet dissolution). The design space was established by the combined use of DOE, optimization and multivariate analysis to ensure desired CQAs. Multivariate analysis of all variables from the DOE batches was conducted to study relationships between the variables and to evaluate the impact of material attributes/process parameters on manufacturability and final product CQAs. The integrated multivariate approach exemplifies application of QbD principles and tools to drug product and process development.

Self-harming in depressed patients: pattern analysis.

PubMed

Parker, G; Malhi, Gin; Mitchell, Philip; Kotze, Beth; Wilhelm, Kay; Parker, Kay

2005-10-01

As deliberate self-harm (DSH) is a common concomitant of depressive disorders, we undertook a study examining the relevance of possible determinants and correlates of DSH. Three separate samples of depressed outpatients were studied to determine consistency of identified factors across samples, with principal analyses involving gender, age and diagnosis-matched DSH and non-DSH subjects. Across the samples, some 20% of subjects admitted to episodes of DSH. Women reported higher rates and there was a consistent trend for higher rates in bipolar patients. Univariate analyses examined the relevance of several sociodemographic variables, illicit drug and alcohol use, past deprivational and abusive experiences, past suicidal attempts and disordered personality functioning. Multivariate analyses consistently identified previous suicide attempts and high 'acting out' behaviours across the three samples, suggesting the relevance of an externalizing response to stress and poor impulse control. Results assist the identification and management of depressed patients who are at greater risk of DSH behaviours.

Usefulness of amino acid composition to discriminate between honeydew and floral honeys. Application to honeys from a small geographic area.

PubMed

Iglesias, María Teresa; De Lorenzo, Cristina; Del Carmen Polo, María; Martín-Alvarez, Pedro Jésus; Pueyo, Encarnacíon

2004-01-14

With the aim of finding methods that could constitute a solid alternative to melissopalynological and physicochemical analyses to determine the botanical origin (floral or honeydew) of honeys, the free amino acid content of 46 honey samples has been determined. The honeys were collected in a small geographic area of approximately 2000 km(2) in central Spain. Twenty-seven honey samples were classified as floral and 19 as honeydew according to their palynological and physicochemical analyses. The resulting data have been subjected to different multivariant analysis techniques. One hundred percent of honey samples have been correctly classified into either the floral or the honeydew groups, according to their content in glutamic acid and tryptophan. It is concluded that free amino acids are good indicators of the botanical origin of honeys, saving time compared with more tedious analyses.

Using Qualitative Metasummary to Synthesize Qualitative and Quantitative Descriptive Findings

PubMed Central

Sandelowski, Margarete; Barroso, Julie; Voils, Corrine I.

2008-01-01

The new imperative in the health disciplines to be more methodologically inclusive has generated a growing interest in mixed research synthesis, or the integration of qualitative and quantitative research findings. Qualitative metasummary is a quantitatively oriented aggregation of qualitative findings originally developed to accommodate the distinctive features of qualitative surveys. Yet these findings are similar in form and mode of production to the descriptive findings researchers often present in addition to the results of bivariate and multivariable analyses. Qualitative metasummary, which includes the extraction, grouping, and formatting of findings, and the calculation of frequency and intensity effect sizes, can be used to produce mixed research syntheses and to conduct a posteriori analyses of the relationship between reports and findings. PMID:17243111

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.

Relationship between cataract severity and socioeconomic status.

PubMed

Wesolosky, Jason D; Rudnisky, Christopher J

2013-12-01

To determine the relationship between cataract severity and socioeconomic status (SES). Retrospective, observational case series. A total of 1350 eyes underwent phacoemulsification cataract extraction by a single surgeon using an Alcon Infiniti system. Cataract severity was measured using phaco time in seconds. SES was measured using area-level aggregate census data: median income, education, proportion of common-law couples, and employment rate. Preoperative best corrected visual acuity was obtained and converted to logarithm of the minimum angle of resolution values. For patients undergoing bilateral surgery, the generalized estimating equation was used to account for the correlation between eyes. Univariate analyses were performed using simple regression, and multivariate analyses were performed to account for variables with significant relationships (p < 0.05) on univariate testing. Sensitivity analyses were performed to assess the effect of including patient age in the controlled analyses. Multivariate analyses demonstrated that cataracts were more severe when the median income was lower (p = 0.001) and the proportion of common-law couples living in a patient's community (p = 0.012) and the unemployment rate (p = 0.002) were higher. These associations persisted even when controlling for patient age. Patients of lower SES have more severe cataracts. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

Prognostic factors for return to work in patients with sciatica.

PubMed

Grøvle, Lars; Haugen, Anne J; Keller, Anne; Ntvig, Bård; Brox, Jens I; Grotle, Margreth

2013-12-01

Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation. To identify the prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care. Multicenter prospective cohort study including 466 patients. Administrative data from the National Sickness Benefit Register were accessed for 227 patients. Two samples were used. Sample A comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave or were undergoing rehabilitation because of back pain/sciatica. Sample B comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica. In Sample A, the outcome was self-reported return to full-time work at the 2-year follow-up. In Sample B, the outcome was time to first sustained RTW, defined as the first period of more than 60 days without receiving benefits from the register. Significant baseline predictors of self-reported RTW at 2 years (Analysis A) were identified by multivariate logistic regression. Significant predictors of time to sustained RTW (Analysis B) were identified by multivariate Cox proportional hazard modeling. Both analyses included adjustment for age and sex. To assess the effect of surgery on the probability of RTW, analyses similar to A and B were performed, including the variable surgery (yes/no). One-fourth of the patients were still out of work at the 2-year follow-up. In Sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear-avoidance work, and a negative straight-leg-raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In Sample B (n=125), history of sciatica, duration of the current sciatica episode more than 3 months, greater sciatica bothersomeness, fear-avoidance work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was significantly negatively associated with time to sustained RTW both in univariate (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.39, 0.93; p=.02) and in multivariate (HR 0.49; 95% CI 0.31, 0.79; p=.003) analyses. The baseline factors associated with RTW identified in multivariate analysis were age, general health, history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear-avoidance work, back pain, and the straight-leg-raising test result. Surgical treatment was associated with slower RTW, but surgical patients were more severely affected than patients treated without surgery; so, this finding should be interpreted with caution. Copyright © 2013 Elsevier Inc. All rights reserved.

Multivariate statistical analysis of low-voltage EDS spectrum images

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

Anderson, I.M.

1998-03-01

Whereas energy-dispersive X-ray spectrometry (EDS) has been used for compositional analysis in the scanning electron microscope for 30 years, the benefits of using low operating voltages for such analyses have been explored only during the last few years. This paper couples low-voltage EDS with two other emerging areas of characterization: spectrum imaging and multivariate statistical analysis. The specimen analyzed for this study was a finished Intel Pentium processor, with the polyimide protective coating stripped off to expose the final active layers.

Power and sample size for multivariate logistic modeling of unmatched case-control studies.

PubMed

Gail, Mitchell H; Haneuse, Sebastien

2017-01-01

Sample size calculations are needed to design and assess the feasibility of case-control studies. Although such calculations are readily available for simple case-control designs and univariate analyses, there is limited theory and software for multivariate unconditional logistic analysis of case-control data. Here we outline the theory needed to detect scalar exposure effects or scalar interactions while controlling for other covariates in logistic regression. Both analytical and simulation methods are presented, together with links to the corresponding software.

Comparison of Optimum Interpolation and Cressman Analyses

NASA Technical Reports Server (NTRS)

Baker, W. E.; Bloom, S. C.; Nestler, M. S.

1984-01-01

The objective of this investigation is to develop a state-of-the-art optimum interpolation (O/I) objective analysis procedure for use in numerical weather prediction studies. A three-dimensional multivariate O/I analysis scheme has been developed. Some characteristics of the GLAS O/I compared with those of the NMC and ECMWF systems are summarized. Some recent enhancements of the GLAS scheme include a univariate analysis of water vapor mixing ratio, a geographically dependent model prediction error correlation function and a multivariate oceanic surface analysis.

Comparison of Optimum Interpolation and Cressman Analyses

NASA Technical Reports Server (NTRS)

Baker, W. E.; Bloom, S. C.; Nestler, M. S.

1985-01-01

The development of a state of the art optimum interpolation (O/I) objective analysis procedure for use in numerical weather prediction studies was investigated. A three dimensional multivariate O/I analysis scheme was developed. Some characteristics of the GLAS O/I compared with those of the NMC and ECMWF systems are summarized. Some recent enhancements of the GLAS scheme include a univariate analysis of water vapor mixing ratio, a geographically dependent model prediction error correlation function and a multivariate oceanic surface analysis.

A comparison of bivariate, multivariate random-effects, and Poisson correlated gamma-frailty models to meta-analyze individual patient data of ordinal scale diagnostic tests.

PubMed

Simoneau, Gabrielle; Levis, Brooke; Cuijpers, Pim; Ioannidis, John P A; Patten, Scott B; Shrier, Ian; Bombardier, Charles H; de Lima Osório, Flavia; Fann, Jesse R; Gjerdingen, Dwenda; Lamers, Femke; Lotrakul, Manote; Löwe, Bernd; Shaaban, Juwita; Stafford, Lesley; van Weert, Henk C P M; Whooley, Mary A; Wittkampf, Karin A; Yeung, Albert S; Thombs, Brett D; Benedetti, Andrea

2017-11-01

Individual patient data (IPD) meta-analyses are increasingly common in the literature. In the context of estimating the diagnostic accuracy of ordinal or semi-continuous scale tests, sensitivity and specificity are often reported for a given threshold or a small set of thresholds, and a meta-analysis is conducted via a bivariate approach to account for their correlation. When IPD are available, sensitivity and specificity can be pooled for every possible threshold. Our objective was to compare the bivariate approach, which can be applied separately at every threshold, to two multivariate methods: the ordinal multivariate random-effects model and the Poisson correlated gamma-frailty model. Our comparison was empirical, using IPD from 13 studies that evaluated the diagnostic accuracy of the 9-item Patient Health Questionnaire depression screening tool, and included simulations. The empirical comparison showed that the implementation of the two multivariate methods is more laborious in terms of computational time and sensitivity to user-supplied values compared to the bivariate approach. Simulations showed that ignoring the within-study correlation of sensitivity and specificity across thresholds did not worsen inferences with the bivariate approach compared to the Poisson model. The ordinal approach was not suitable for simulations because the model was highly sensitive to user-supplied starting values. We tentatively recommend the bivariate approach rather than more complex multivariate methods for IPD diagnostic accuracy meta-analyses of ordinal scale tests, although the limited type of diagnostic data considered in the simulation study restricts the generalization of our findings. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kidney transplantation from deceased donors with elevated serum creatinine.

PubMed

Gallinat, Anja; Leerhoff, Sabine; Paul, Andreas; Molmenti, Ernesto P; Schulze, Maren; Witzke, Oliver; Sotiropoulos, Georgios C

2016-12-01

Elevated donor serum creatinine has been associated with inferior graft survival in kidney transplantation (KT). The aim of this study was to evaluate the impact of elevated donor serum creatinine on short and long-term outcomes and to determine possible ways to optimize the use of these organs. All kidney transplants from 01-2000 to 12-2012 with donor creatinine ≥ 2 mg/dl were considered. Risk factors for delayed graft function (DGF) were explored with uni- and multivariate regression analyses. Donor and recipient data were analyzed with uni- and multivariate cox proportional hazard analyses. Graft and patient survival were calculated using the Kaplan-Meier method. Seventy-eight patients were considered. Median recipient age and waiting time on dialysis were 53 years and 5.1 years, respectively. After a median follow-up of 6.2 years, 63 patients are alive. 1, 3, and 5-year graft and patient survival rates were 92, 89, and 89 % and 96, 93, and 89 %, respectively. Serum creatinine level at procurement and recipient's dialysis time prior to KT were predictors of DGF in multivariate analysis (p = 0.0164 and p = 0.0101, respectively). Charlson comorbidity score retained statistical significance by multivariate regression analysis for graft survival (p = 0.0321). Recipient age (p = 0.0035) was predictive of patient survival by multivariate analysis. Satisfactory long-term kidney transplant outcomes in the setting of elevated donor serum creatinine ≥2 mg/dl can be achieved when donor creatinine is <3.5 mg/dl, and the recipient has low comorbidities, is under 56 years of age, and remains in dialysis prior to KT for <6.8 years.

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

Wang, C. L.; Funk, L. L.; Riedel, R. A.

3He gas based neutron linear-position-sensitive detectors (LPSDs) have been applied for many neutron scattering instruments. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio on the orders of 10 5-10 6. The NGD ratios of 3He detectors need to be improved for even better scientific results from neutron scattering. Digital Signal Processing (DSP) analyses of waveforms were proposed for obtaining better NGD ratios, based on features extracted from rise-time, pulse amplitude, charge integration, a simplified Wiener filter, and the cross-correlation between individual and template waveforms of neutron and gamma events. Fisher linear discriminant analysis (FLDA)more » and three multivariate analyses (MVAs) of the features were performed. The NGD ratios are improved by about 10 2-10 3 times compared with the traditional PHA method. Finally, our results indicate the NGD capabilities of 3He tube detectors can be significantly improved with subspace-learning based methods, which may result in a reduced data-collection time and better data quality for further data reduction.« less

Vegetation characteristics important to common songbirds in east Texas

USGS Publications Warehouse

Conner, Richard N.; Dickson, James G.; Locke, Brian A.; Segelquist, Charles A.

1983-01-01

Multivariate studies of breeding bird communities have used principal component analysis (PCA) or several-group (three or more groups) discriminant function analysis (DFA) to ordinate bird species on vegetational continua (Cody 1968, James 1971, Whitmore 1975). In community studies, high resolution of habitat requirements for individual species is not always possible with either PCA or several-group DFA. When habitat characteristics of several species are examined with a DFA the resultant axes optimally discriminate among all species simultaneously. Hence, the characteristics assigned to a particular species reflect in part the presence of other species in the analyses. A better resolution of each species' habitat requirements may be obtained from a two-group DFA, wherein habitats selected by a species are discriminated from all other available habitats. Analyses using two-group DFAs to compare habitat used by a species with habitat unused by the same species have the potential to provide an optimal frame of reference from which to examine habitat variables (Martinka 1972, Conner and Adkisson 1976, Whitmore 1981). Mathematically (DFA) it is possible to maximally separate two groups of multivariate observations with a single axis (Harner and whitmore 1977). A line drawn in three or n-dimensional space can easily be positioned to intersect two multivariate means (centroids). If three or more centroids for species are analyzed simultaneously, a single line can no longer intersect all centroids unless a perfectly linear relationship exists for the species being examined. The probability of such an occurrence is extremely low. Thus, a high degree of resolution can be realized when a two-group DFA is used to determine habitat parameters important to individual species. We have used two-group DFA to identify vegetation variable important to 12 common species of songbirds in East Texas.

Acoustic neuroma: potential risk factors and audiometric surveillance in the aluminium industry.

PubMed

Taiwo, Oyebode; Galusha, Deron; Tessier-Sherman, Baylah; Kirsche, Sharon; Cantley, Linda; Slade, Martin D; Cullen, Mark R; Donoghue, A Michael

2014-09-01

To look for an association between acoustic neuroma (AN) and participation in a hearing conservation programme (HCP) and also for an association between AN and possible occupational risk factors in the aluminium industry. We conducted a case-control analysis of a population of US aluminium production workers in 8 smelters and 43 other plants. Using insurance claims data, 97 cases of AN were identified between 1996 and 2009. Each was matched with four controls. Covariates included participation in a HCP, working in an aluminium smelter, working in an electrical job and hearing loss. In the bivariate analyses, covariates associated with AN were participation in the HCP (OR=1.72; 95% CI 1.09 to 2.69) and smelter work (OR=1.88; 95% CI 1.06 to 3.36). Electrical work was not significant (OR=1.60; 95% CI 0.65 to 3.94). Owing to high participation in the HCP in smelters, multivariate subanalyses were required. In the multivariate analyses, participation in the HCP was the only statistically significant risk factor for AN. In the multivariate analysis restricted to employees not working in a smelter, the OR was 1.81 (95% CI 1.04 to 3.17). Hearing loss, an indirect measure of in-ear noise dose, was not predictive of AN. Our results suggest the incidental detection of previously undiagnosed tumours in workers who participated in the company-sponsored HCP. The increased medical surveillance among this population of workers most likely introduced detection bias, leading to the identification of AN cases that would have otherwise remained undetected. 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.

Preference-based Health status in a German outpatient cohort with multiple sclerosis

PubMed Central

2013-01-01

Background To prospectively determine health status and health utility and its predictors in patients with multiple sclerosis (MS). Methods A total of 144 MS patients (mean age: 41.0 ±11.3y) with different subtypes (patterns of progression) and severities of MS were recruited in an outpatient university clinic in Germany. Patients completed a questionnaire at baseline (n = 144), 6 months (n = 65) and 12 months (n = 55). Health utilities were assessed using the EuroQol instrument (EQ-5D, EQ VAS). Health status was assessed by several scales (Expanded Disability Severity Scale (EDSS), Modified Fatigue Impact Scale (M-FIS), Functional Assessment of MS (FAMS), Beck Depression Inventory (BDI-II) and Multiple Sclerosis Functional Composite (MSFC)). Additionally, demographic and socioeconomic parameters were assessed. Multivariate linear and logistic regressions were applied to reveal independent predictors of health status. Results Health status is substantially diminished in MS patients and the EQ VAS was considerably lower than that of the general German population. No significant change in health-status parameters was observed over a 12-months period. Multivariate analyses revealed M-FIS, BDI-II, MSFC, and EDSS to be significant predictors of reduced health status. Socioeconomic and socio-demographic parameters such as working status, family status, number of household inhabitants, age, and gender did not prove significant in multivariate analyses. Conclusion MS considerably impairs patients’ health status. Guidelines aiming to improve self-reported health status should include treatment options for depression and fatigue. Physicians should be aware of depression and fatigue as co-morbidities. Future studies should consider the minimal clinical difference when health status is a primary outcome. PMID:24089999

Sexual Assault Disclosure: The Effect of Victim Race and Perpetrator Type on Empathy, Culpability, and Service Referral for Survivors in a Hypothetical Scenario.

PubMed

Franklin, Cortney A; Garza, Alondra D

2018-03-01

The aftermath of sexual assault warrants further attention surrounding the responses provided by those to whom survivors disclose, especially when perpetrator type or victim race may affect whether the bystander response is supportive or attributes culpability to the victim. Disclosure responses have significant consequences for survivors' posttrauma mental health and formal help-seeking behavior. The current study used a sample of 348 self-report, paper-and-pencil surveys administered during the fall 2015 semester to a purposive sample of undergraduate students with a mean age of 20.94 years old at a midsized, Southern public university. Survey design included a randomly assigned 2 × 2 hypothetical sexual assault disclosure vignette. The objective of the study was to assess the effect of perpetrator type (stranger vs. acquaintance) and victim race (White vs. Black) on empathic concern, culpability attributions, and resource referral. Between-subjects factorial ANOVA and multivariate ordinary least squares (OLS) regression models were estimated to identify the role of vignette manipulations, participant-sexual victimization history, and rape myth acceptance on empathy, culpability, and resource referral for the sexual assault survivor portrayed in the vignette. Multivariate analyses included main effects and moderation models. Findings revealed increased culpability and decreased resource referral for victims of acquaintance rape as compared with stranger rape, independent of victim race. Although no direct victim race effects emerged in the multivariate analyses, race moderated the effect of culpability on resource referral indicating culpability attributions decreased resource referral, but only when the victim was Black . Implications from the results presented here include a continued focus on bystander intervention strategies, empathy-building techniques, and educational programming targeting potential sexual assault disclosees and race stereotypes that disadvantage victims of color.

Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities.

PubMed

Machicado, Jorge D; Amann, Stephen T; Anderson, Michelle A; Abberbock, Judah; Sherman, Stuart; Conwell, Darwin L; Cote, Gregory A; Singh, Vikesh K; Lewis, Michele D; Alkaade, Samer; Sandhu, Bimaljit S; Guda, Nalini M; Muniraj, Thiruvengadam; Tang, Gong; Baillie, John; Brand, Randall E; Gardner, Timothy B; Gelrud, Andres; Forsmark, Christopher E; Banks, Peter A; Slivka, Adam; Wilcox, C Mel; Whitcomb, David C; Yadav, Dhiraj

2017-04-01

Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients. We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. Mean PCS and MCS scores were 36.7±11.7 and 42.4±12.2, respectively. Significant (P<0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild-moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild-moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P<0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8-6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses.

NIH disease funding levels and burden of disease.

PubMed

Gillum, Leslie A; Gouveia, Christopher; Dorsey, E Ray; Pletcher, Mark; Mathers, Colin D; McCulloch, Charles E; Johnston, S Claiborne

2011-02-24

An analysis of NIH funding in 1996 found that the strongest predictor of funding, disability-adjusted life-years (DALYs), explained only 39% of the variance in funding. In 1998, Congress requested that the Institute of Medicine (IOM) evaluate priority-setting criteria for NIH funding; the IOM recommended greater consideration of disease burden. We examined whether the association between current burden and funding has changed since that time. We analyzed public data on 2006 NIH funding for 29 common conditions. Measures of US disease burden in 2004 were obtained from the World Health Organization's Global Burden of Disease study and national databases. We assessed the relationship between disease burden and NIH funding dollars in univariate and multivariable log-linear models that evaluated all measures of disease burden. Sensitivity analyses examined associations with future US burden, current and future measures of world disease burden, and a newly standardized NIH accounting method. In univariate and multivariable analyses, disease-specific NIH funding levels increased with burden of disease measured in DALYs (p = 0.001), which accounted for 33% of funding level variation. No other factor predicted funding in multivariable models. Conditions receiving the most funding greater than expected based on disease burden were AIDS ($2474 M), diabetes mellitus ($390 M), and perinatal conditions ($297 M). Depression ($719 M), injuries ($691 M), and chronic obstructive pulmonary disease ($613 M) were the most underfunded. Results were similar using estimates of future US burden, current and future world disease burden, and alternate NIH accounting methods. Current levels of NIH disease-specific research funding correlate modestly with US disease burden, and correlation has not improved in the last decade.

Long-term outcome of pronation-external rotation ankle fractures treated with syndesmotic screws only.

PubMed

Lambers, Kaj T A; van den Bekerom, Michel P J; Doornberg, Job N; Stufkens, Sjoerd A S; van Dijk, C Niek; Kloen, Peter

2013-09-04

There is sparse information in the literature on the outcome of Maisonneuve-type pronation-external rotation ankle fractures treated with syndesmotic screws. The primary aim of this study was to determine the long-term results of such treatment of these fractures as indicated by standardized patient-based and physician-based outcome measures. The secondary aim was to identify predictors of the outcome with use of bivariate and multivariate statistical analysis. Fifty patients with pronation-external rotation (predominantly Maisonneuve) fractures were treated with open reduction and internal fixation of the syndesmosis utilizing only one or two screws. The results were evaluated at a mean of twenty-one years after the fracture utilizing three standardized outcomes instruments: (1) the Foot and Ankle Ability Measure (FAAM), (2) the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, and (3) the Center for Epidemiologic Studies-Depression (CES-D) Scale. Osteoarthritis was graded according to the van Dijk and revised Takakura radiographic scoring systems. Bivariate and multivariate analyses were performed to identify predictors of long-term outcome. Forty-four (92%) of forty-eighty patients had good or excellent AOFAS scores, and forty-four (90%) of forty-nine had good or excellent FAAM scores. Arthrodesis for severe osteoarthritis was performed in two patients. Radiographic evidence of osteoarthritis was observed in twenty-four (49%) of forty-nine patients. Multivariate analysis identified pain as the most important independent predictor of long-term ankle function as indicated by the AOFAS and FAAM scores, explaining 91% and 53% of the variation in scores, respectively. Analysis of pain as the dependent variable in bivariate analyses revealed that depression, ankle range of motion, and a subsequent surgery were significantly correlated with higher pain scores. No firm conclusions could be drawn after multivariate analysis of predictors of pain. Long-term functional outcomes at a mean of twenty-one years after pronation-external rotation ankle fractures treated with one or two syndesmotic screws were good to excellent in the great majority of patients despite substantial radiographic evidence of osteoarthritis in one-half of the patients. The most important predictor of long-term functional outcome was patient-reported pain rather than physician-reported function or posttraumatic osteoarthritis. There was no significant association between radiographic signs of posttraumatic osteoarthritis and perceived pain in the present series.

No evidence of somatotopic place of articulation feature mapping in motor cortex during passive speech perception.

PubMed

Arsenault, Jessica S; Buchsbaum, Bradley R

2016-08-01

The motor theory of speech perception has experienced a recent revival due to a number of studies implicating the motor system during speech perception. In a key study, Pulvermüller et al. (2006) showed that premotor/motor cortex differentially responds to the passive auditory perception of lip and tongue speech sounds. However, no study has yet attempted to replicate this important finding from nearly a decade ago. The objective of the current study was to replicate the principal finding of Pulvermüller et al. (2006) and generalize it to a larger set of speech tokens while applying a more powerful statistical approach using multivariate pattern analysis (MVPA). Participants performed an articulatory localizer as well as a speech perception task where they passively listened to a set of eight syllables while undergoing fMRI. Both univariate and multivariate analyses failed to find evidence for somatotopic coding in motor or premotor cortex during speech perception. Positive evidence for the null hypothesis was further confirmed by Bayesian analyses. Results consistently show that while the lip and tongue areas of the motor cortex are sensitive to movements of the articulators, they do not appear to preferentially respond to labial and alveolar speech sounds during passive speech perception.

Analysis of threats to research validity introduced by audio recording clinic visits: Selection bias, Hawthorne effect, both, or neither?

PubMed Central

Henry, Stephen G.; Jerant, Anthony; Iosif, Ana-Maria; Feldman, Mitchell D.; Cipri, Camille; Kravitz, Richard L.

2015-01-01

Objective To identify factors associated with participant consent to record visits; to estimate effects of recording on patient-clinician interactions Methods Secondary analysis of data from a randomized trial studying communication about depression; participants were asked for optional consent to audio record study visits. Multiple logistic regression was used to model likelihood of patient and clinician consent. Multivariable regression and propensity score analyses were used to estimate effects of audio recording on 6 dependent variables: discussion of depressive symptoms, preventive health, and depression diagnosis; depression treatment recommendations; visit length; visit difficulty. Results Of 867 visits involving 135 primary care clinicians, 39% were recorded. For clinicians, only working in academic settings (P=0.003) and having worked longer at their current practice (P=0.02) were associated with increased likelihood of consent. For patients, white race (P=0.002) and diabetes (P=0.03) were associated with increased likelihood of consent. Neither multivariable regression nor propensity score analyses revealed any significant effects of recording on the variables examined. Conclusion Few clinician or patient characteristics were significantly associated with consent. Audio recording had no significant effect on any dependent variables. Practice Implications Benefits of recording clinic visits likely outweigh the risks of bias in this setting. PMID:25837372

Impact of Primary Gleason Grade on Risk Stratification for Gleason Score 7 Prostate Cancers

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

Koontz, Bridget F., E-mail: bridget.koontz@duke.edu; Tsivian, Matvey; Mouraviev, Vladimir

Purpose: To evaluate the primary Gleason grade (GG) in Gleason score (GS) 7 prostate cancers for risk of non-organ-confined disease with the goal of optimizing radiotherapy treatment option counseling. Methods: One thousand three hundred thirty-three patients with pathologic GS7 were identified in the Duke Prostate Center research database. Clinical factors including age, race, clinical stage, prostate-specific antigen at diagnosis, and pathologic stage were obtained. Data were stratified by prostate-specific antigen and clinical stage at diagnosis into adapted D'Amico risk groups. Univariate and multivariate analyses were performed evaluating for association of primary GG with pathologic outcome. Results: Nine hundred seventy-nine patientsmore » had primary GG3 and 354 had GG4. On univariate analyses, GG4 was associated with an increased risk of non-organ-confined disease. On multivariate analysis, GG4 was independently associated with seminal vesicle invasion (SVI) but not extracapsular extension. Patients with otherwise low-risk disease and primary GG3 had a very low risk of SVI (4%). Conclusions: Primary GG4 in GS7 cancers is associated with increased risk of SVI compared with primary GG3. Otherwise low-risk patients with GS 3+4 have a very low risk of SVI and may be candidates for prostate-only radiotherapy modalities.« less

Are social relationships a healthy influence on obesogenic behaviors among racially/ethnically diverse and socio-economically disadvantaged residents?

PubMed Central

Tamers, Sara L.; Okechukwu, Cassandra; Allen, Jennifer; Yang, May; Stoddard, Anne; Tucker-Seeley, Reginald; Sorensen, Glorian

2012-01-01

Objective To examine associations between social support and ties (family, friend, neighbors) individually and jointly with diet and physical activity among an ethnically-diverse, low-income population. Methods The Health in Common study (2005–2009) was designed to examine risk factors among individuals residing in low-income housing in the Boston, MA area. Cross-sectional surveys (n = 828) were administered in residents’ homes. Linear/logistic multivariable analyses were employed with clustering of individuals within housing sites controlled as a random effect. Results In multivariable analyses, total social support was significantly associated with higher red meat consumption per day (p = 0.029). Having more friends was significantly associated with more daily fruit and vegetable intake (p = 0.007) and higher levels of daily vigorous physical activity (p = 0.011). Those who reported having a greater number of family ties also reported higher daily consumption of sugary drinks (p = 0.013) and fast food (p = 0.011). More neighbor social ties was associated with more fast food per day (p = 0.024). Conclusions Social relationships can have both positive and negative associations with health behaviors. Understanding these relationships could help to inform the design of interventions that promote healthy behavior change among vulnerable populations. PMID:23200880

Risk factors for urinary tract infection in children with urinary urgency.

PubMed

Gondim, Rhaiana; Azevedo, Roberta; Braga, Ana Aparecida Nascimento Martinelli; Veiga, Maria Luiza; Barroso, Ubirajara

2018-01-01

To identify which independent variable would be strong predictor of febrile urinary tract infection (UTI) in children and adolescents with overactive bladder. A search was made of the institute's database for all patients diagnosed with overactive bladder over the preceding four years. Children and adolescents under 18 years of age with overactive bladder and no neurological or anatomical alterations of the lower urinary tract were included in the study. The independent variables were: sex, age, ethnicity (Brazilians of African descendence/others), the presence of urinary urgency, daytime incontinence, enuresis, frequent urination, infrequent voiding (≤3 voids/day), nocturia, holding maneuvers, straining to void, intermittent urinary flow, constipation and encopresis. An analysis was conducted to identify patients with febrile UTI and subsequently determine predictors of this condition. Univariate and multivariate analyses were performed. Overall, 326 patients (214 girls/112 boys) were evaluated. The mean age of the patients was 7.7±3.19 years (± standard deviation). The incidence of febrile UTI was 39.2%. Being female and infrequent voiding were factors significantly associated with febrile UTI, both in the univariate and multivariate analyses. These results show that being female and infrequent voiding constituted significant risk factors for a diagnosis of febrile UTI in these children. Copyright® by the International Brazilian Journal of Urology.

Characterization of Lavandula spp. Honey Using Multivariate Techniques.

PubMed

Estevinho, Leticia M; Chambó, Emerson Dechechi; Pereira, Ana Paula Rodrigues; Carvalho, Carlos Alfredo Lopes de; Toledo, Vagner de Alencar Arnaut de

2016-01-01

Traditionally, melissopalynological and physicochemical analyses have been the most used to determine the botanical origin of honey. However, when performed individually, these analyses may provide less unambiguous results, making it difficult to discriminate between mono and multifloral honeys. In this context, with the aim of better characterizing this beehive product, a selection of 112 Lavandula spp. monofloral honey samples from several regions were evaluated by association of multivariate statistical techniques with physicochemical, melissopalynological and phenolic compounds analysis. All honey samples fulfilled the quality standards recommended by international legislation, except regarding sucrose content and diastase activity. The content of sucrose and the percentage of Lavandula spp. pollen have a strong positive association. In fact, it was found that higher amounts of sucrose in honey are related with highest percentage of pollen of Lavandula spp.. The samples were very similar for most of the physicochemical parameters, except for proline, flavonoids and phenols (bioactive factors). Concerning the pollen spectrum, the variation of Lavandula spp. pollen percentage in honey had little contribution to the formation of samples groups. The formation of two groups regarding the physicochemical parameters suggests that the presence of other pollen types in small percentages influences the factor termed as "bioactive", which has been linked to diverse beneficial health effects.

Characterization of Lavandula spp. Honey Using Multivariate Techniques

PubMed Central

2016-01-01

Traditionally, melissopalynological and physicochemical analyses have been the most used to determine the botanical origin of honey. However, when performed individually, these analyses may provide less unambiguous results, making it difficult to discriminate between mono and multifloral honeys. In this context, with the aim of better characterizing this beehive product, a selection of 112 Lavandula spp. monofloral honey samples from several regions were evaluated by association of multivariate statistical techniques with physicochemical, melissopalynological and phenolic compounds analysis. All honey samples fulfilled the quality standards recommended by international legislation, except regarding sucrose content and diastase activity. The content of sucrose and the percentage of Lavandula spp. pollen have a strong positive association. In fact, it was found that higher amounts of sucrose in honey are related with highest percentage of pollen of Lavandula spp.. The samples were very similar for most of the physicochemical parameters, except for proline, flavonoids and phenols (bioactive factors). Concerning the pollen spectrum, the variation of Lavandula spp. pollen percentage in honey had little contribution to the formation of samples groups. The formation of two groups regarding the physicochemical parameters suggests that the presence of other pollen types in small percentages influences the factor termed as “bioactive”, which has been linked to diverse beneficial health effects. PMID:27588420

Low creatinine clearance is a risk factor for D2 gastrectomy after neoadjuvant chemotherapy.

PubMed

Hayashi, Tsutomu; Aoyama, Toru; Tanabe, Kazuaki; Nishikawa, Kazuhiro; Ito, Yuichi; Ogata, Takashi; Cho, Haruhiko; Morita, Satoshi; Miyashita, Yumi; Tsuburaya, Akira; Sakamoto, Junichi; Yoshikawa, Takaki

2014-09-01

The feasibility and safety of D2 surgery following neoadjuvant chemotherapy (NAC) has not been fully evaluated in patients with gastric cancer. Moreover, risk factor for surgical complications after D2 gastrectomy following NAC is also unknown. The purpose of the present study was to identify risk factors of postoperative complications after D2 surgery following NAC. This study was conducted as an exploratory analysis of a prospective, randomized Phase II trial of NAC. The surgical complications were assessed and classified according to the Clavien-Dindo classification. A uni- and multivariate logistic regression analyses were performed to identify risk factors for morbidity. Among 83 patients who were registered to the Phase II trial, 69 patients received the NAC and D2 gastrectomy. Postoperative complications were identified in 18 patients and the overall morbidity rate was 26.1 %. The results of univariate and multivariate analyses of various factors for overall operative morbidity, creatinine clearance (CCr) ≤ 60 ml/min (P = 0.016) was identified as sole significant independent risk factor for overall morbidity. Occurrence of pancreatic fistula was significantly higher in the patients with a low CCr than in those with a high CCr. Low CCr was a significant risk factor for surgical complications in D2 gastrectomy after NAC. Careful attention is required for these patients.

Complex patterns of multivariate selection on the ejaculate of a broadcast spawning marine invertebrate.

PubMed

Fitzpatrick, John L; Simmons, Leigh W; Evans, Jonathan P

2012-08-01

Assessing how selection operates on several, potentially interacting, components of the ejaculate is a challenging endeavor. Ejaculates can be subject to natural and/or sexual selection, which can impose both linear (directional) and nonlinear (stabilizing, disruptive, and correlational) selection on different ejaculate components. Most previous studies have examined linear selection of ejaculate components and, consequently, we know very little about patterns of nonlinear selection on the ejaculate. Even less is known about how selection acts on the ejaculate as a functionally integrated unit, despite evidence of covariance among ejaculate components. Here, we assess how selection acts on multiple ejaculate components simultaneously in the broadcast spawning sessile invertebrate Mytilus galloprovincialis using the statistical tools of multivariate selection analyses. Our analyses of relative fertilization rates revealed complex patterns of selection on sperm velocity, motility, and morphology. Interestingly, the most successful ejaculates were made up of slower swimming sperm with relatively low percentages of motile cells, and sperm with smaller head volumes that swam in highly pronounced curved swimming trajectories. These results are consistent with an emerging body of literature on fertilization kinetics in broadcast spawners, and shed light on the fundamental nature of selection acting on the ejaculate as a functionally integrated unit. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Predictive factors for 1-year outcome of a cohort of patients with severe traumatic brain injury (TBI): results from the PariS-TBI study.

PubMed

Jourdan, C; Bosserelle, V; Azerad, S; Ghout, I; Bayen, E; Aegerter, P; Weiss, J J; Mateo, J; Lescot, T; Vigué, B; Tazarourte, K; Pradat-Diehl, P; Azouvi, P

2013-01-01

To assess outcome and predicting factors 1 year after a severe traumatic brain injury (TBI). Multi-centre prospective inception cohort study of patients aged 15 or older with a severe TBI in the Parisian area, France. Data were collected prospectively starting the day of injury. One-year evaluation included the relatives-rating of the Dysexecutive Questionnaire (DEX-R), the Glasgow Outcome Scale-Extended (GOSE) and employment. Univariate and multivariate tests were computed. Among 257 survivors, 134 were included (mean age 36 years, 84% men). Good recovery concerned 19%, moderate disability 43% and severe disability 38%. Among patients employed pre-injury, 42% were working, 28% with no job change. DEX-R score was significantly associated with length of education only. Among initial severity measures, only the IMPACT prognostic score was significantly related to GOSE in univariate analyses, while measures relating to early evolution were more significant predictors. In multivariate analyses, independent predictors of GOSE were length of stay in intensive care (LOS), age and education. Independent predictors of employment were LOS and age. Age, education and injury severity are independent predictors of global disability and return to work 1 year after a severe TBI.

EEG artifacts reduction by multivariate empirical mode decomposition and multiscale entropy for monitoring depth of anaesthesia during surgery.

PubMed

Liu, Quan; Chen, Yi-Feng; Fan, Shou-Zen; Abbod, Maysam F; Shieh, Jiann-Shing

2017-08-01

Electroencephalography (EEG) has been widely utilized to measure the depth of anaesthesia (DOA) during operation. However, the EEG signals are usually contaminated by artifacts which have a consequence on the measured DOA accuracy. In this study, an effective and useful filtering algorithm based on multivariate empirical mode decomposition and multiscale entropy (MSE) is proposed to measure DOA. Mean entropy of MSE is used as an index to find artifacts-free intrinsic mode functions. The effect of different levels of artifacts on the performances of the proposed filtering is analysed using simulated data. Furthermore, 21 patients' EEG signals are collected and analysed using sample entropy to calculate the complexity for monitoring DOA. The correlation coefficients of entropy and bispectral index (BIS) results show 0.14 ± 0.30 and 0.63 ± 0.09 before and after filtering, respectively. Artificial neural network (ANN) model is used for range mapping in order to correlate the measurements with BIS. The ANN method results show strong correlation coefficient (0.75 ± 0.08). The results in this paper verify that entropy values and BIS have a strong correlation for the purpose of DOA monitoring and the proposed filtering method can effectively filter artifacts from EEG signals. The proposed method performs better than the commonly used wavelet denoising method. This study provides a fully adaptive and automated filter for EEG to measure DOA more accuracy and thus reduce risk related to maintenance of anaesthetic agents.

Multivariate analyses of tinnitus complaint and change in tinnitus complaint: a masker study.

PubMed

Jakes, S; Stephens, S D

1987-11-01

Multivariate statistical techniques were used to re-analyse the data from the recent DHSS multi-centre masker study. These analyses were undertaken to three ends. First, to clarify and attempt to replicate the previously found factor structure of complaints about tinnitus. Secondly, to attempt to identify common factors in the change or improvement measures pre- and post-masker treatment. Thirdly, to identify predictors of any such outcome factors. Two complaint factors were identified; 'Distress' and 'intrusiveness'. A series of analyses were conducted on change measures using different numbers of subjects and variables. When only semantic differential scales were used, the change factors were very similar to the complaint factors noted above. When variables measuring other aspects of improvement were included, several other factors were identified. These included; 'tinnitus helped', 'masking effects', 'residual inhibition' and 'matched loudness'. Twenty-five conceptually distinct predictors of outcome were identified. These predictor variables were quite different for different outcome factors. For example, high-frequency hearing loss was a predictor of tinnitus being helped by the masker, and a low frequency match and a low masking threshold predicted therapeutic success on residual inhibition. Decrease in matched loudness was predicted by louder tinnitus initially.

Multivariate analysis of the geochemistry and mineralogy of soils along two continental-scale transects in North America

USGS Publications Warehouse

Drew, L.J.; Grunsky, E.C.; Sutphin, D.M.; Woodruff, L.G.

2010-01-01

Soils collected in 2004 along two North American continental-scale transects were subjected to geochemical and mineralogical analyses. In previous interpretations of these analyses, data were expressed in weight percent and parts per million, and thus were subject to the effect of the constant-sum phenomenon. In a new approach to the data, this effect was removed by using centered log-ratio transformations to 'open' the mineralogical and geochemical arrays. Multivariate analyses, including principal component and linear discriminant analyses, of the centered log-ratio data reveal the effects of soil-forming processes, including soil parent material, weathering, and soil age, at the continental-scale of the data arrays that were not readily apparent in the more conventionally presented data. Linear discriminant analysis of the data arrays indicates that the majority of the soil samples collected along the transects can be more successfully classified with Level 1 ecological regional-scale classification by the soil geochemistry than soil mineralogy. A primary objective of this study is to discover and describe, in a parsimonious way, geochemical processes that are both independent and inter-dependent and manifested through compositional data including estimates of the elements and corresponding mineralogy. ?? 2010.

Correlation between smoking habit and surgical outcomes on viral-associated hepatocellular carcinomas.

PubMed

Kai, Keita; Komukai, Sho; Koga, Hiroki; Yamaji, Koutaro; Ide, Takao; Kawaguchi, Atsushi; Aishima, Shinichi; Noshiro, Hirokazu

2018-01-07

To investigate the association between smoking habits and surgical outcomes in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) (B-HCC) and hepatitis C virus (HCV)-related HCC (C-HCC) and clarify the clinicopathological features associated with smoking status in B-HCC and C-HCC patients. We retrospectively examined the cases of the 341 consecutive patients with viral-associated HCC (C-HCC, n = 273; B-HCC, n = 68) who underwent curative surgery for their primary lesion. We categorized smoking status at the time of surgery into never, ex- and current smoker. We analyzed the B-HCC and C-HCC groups' clinicopathological features and surgical outcomes, i.e ., disease-free survival (DFS), overall survival (OS), and disease-specific survival (DSS). Univariate and multivariate analyses were performed using a Cox proportional hazards regression model. We also performed subset analyses in both patient groups comparing the current smokers to the other patients. The multivariate analysis in the C-HCC group revealed that current-smoker status was significantly correlated with both OS ( P = 0.0039) and DSS ( P = 0.0416). In the B-HCC patients, no significant correlation was observed between current-smoker status and DFS, OS, or DSS in the univariate or multivariate analyses. The subset analyses comparing the current smokers to the other patients in both the C-HCC and B-HCC groups revealed that the current smokers developed HCC at significantly younger ages than the other patients irrespective of viral infection status. A smoking habit is significantly correlated with the overall and disease-specific survivals of patients with C-HCC. In contrast, the B-HCC patients showed a weak association between smoking status and surgical outcomes.

Comprehensive untargeted metabolomics of Lychnnophorinae subtribe (Asteraceae: Vernonieae) in a phylogenetic context.

PubMed

Martucci, Maria Elvira Poleti; Loeuille, Benoit; Pirani, José Rubens; Gobbo-Neto, Leonardo

2018-01-01

Members of the subtribe Lychnophorinae occur mostly within the Cerrado domain of the Brazilian Central Plateau. The relationships between its 11 genera, as well as between Lychnophorinae and other subtribes belonging to the tribe Vernonieae, have recently been investigated upon a phylogeny based on molecular and morphological data. We report the use of a comprehensive untargeted metabolomics approach, combining HPLC-MS and GC-MS data, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. We analyzed 78 species by UHPLC-MS and GC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in MetAlign and in MSClust and the matrices generated were used in SIMCA for hierarchical cluster analyses, principal component analyses and orthogonal partial least square discriminant analysis. The results showed that metabolomic analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels (Lychnophora or Eremanthus). Our results confirm that data generated using metabolomics provide evidence for chemotaxonomical studies, especially for phylogenetic inference of the Lychnophorinae subtribe and insight into the evolution of the secondary metabolites of this group.

Comprehensive untargeted metabolomics of Lychnnophorinae subtribe (Asteraceae: Vernonieae) in a phylogenetic context

PubMed Central

Martucci, Maria Elvira Poleti; Loeuille, Benoit; Pirani, José Rubens

2018-01-01

Members of the subtribe Lychnophorinae occur mostly within the Cerrado domain of the Brazilian Central Plateau. The relationships between its 11 genera, as well as between Lychnophorinae and other subtribes belonging to the tribe Vernonieae, have recently been investigated upon a phylogeny based on molecular and morphological data. We report the use of a comprehensive untargeted metabolomics approach, combining HPLC-MS and GC-MS data, followed by multivariate analyses aiming to assess the congruence between metabolomics data and the phylogenetic hypothesis, as well as its potential as a chemotaxonomic tool. We analyzed 78 species by UHPLC-MS and GC-MS in both positive and negative ionization modes. The metabolic profiles obtained for these species were treated in MetAlign and in MSClust and the matrices generated were used in SIMCA for hierarchical cluster analyses, principal component analyses and orthogonal partial least square discriminant analysis. The results showed that metabolomic analyses are mostly congruent with the phylogenetic hypothesis especially at lower taxonomic levels (Lychnophora or Eremanthus). Our results confirm that data generated using metabolomics provide evidence for chemotaxonomical studies, especially for phylogenetic inference of the Lychnophorinae subtribe and insight into the evolution of the secondary metabolites of this group. PMID:29324799

Retrospective Analysis of Radiological Recurrence Patterns in Glioblastoma, Their Prognostic Value And Association to Postoperative Infarct Volume.

PubMed

Bette, Stefanie; Barz, Melanie; Huber, Thomas; Straube, Christoph; Schmidt-Graf, Friederike; Combs, Stephanie E; Delbridge, Claire; Gerhardt, Julia; Zimmer, Claus; Meyer, Bernhard; Kirschke, Jan S; Boeckh-Behrens, Tobias; Wiestler, Benedikt; Gempt, Jens

2018-03-14

Recent studies suggested that postoperative hypoxia might trigger invasive tumor growth, resulting in diffuse/multifocal recurrence patterns. Aim of this study was to analyze distinct recurrence patterns and their association to postoperative infarct volume and outcome. 526 consecutive glioblastoma patients were analyzed, of which 129 met our inclusion criteria: initial tumor diagnosis, surgery, postoperative diffusion-weighted imaging and tumor recurrence during follow-up. Distinct patterns of contrast-enhancement at initial diagnosis and at first tumor recurrence (multifocal growth/progression, contact to dura/ventricle, ependymal spread, local/distant recurrence) were recorded by two blinded neuroradiologists. The association of radiological patterns to survival and postoperative infarct volume was analyzed by uni-/multivariate survival analyses and binary logistic regression analysis. With increasing postoperative infarct volume, patients were significantly more likely to develop multifocal recurrence, recurrence with contact to ventricle and contact to dura. Patients with multifocal recurrence (Hazard Ratio (HR) 1.99, P = 0.010) had significantly shorter OS, patients with recurrent tumor with contact to ventricle (HR 1.85, P = 0.036), ependymal spread (HR 2.97, P = 0.004) and distant recurrence (HR 1.75, P = 0.019) significantly shorter post-progression survival in multivariate analyses including well-established prognostic factors like age, Karnofsky Performance Score (KPS), therapy, extent of resection and patterns of primary tumors. Postoperative infarct volume might initiate hypoxia-mediated aggressive tumor growth resulting in multifocal and diffuse recurrence patterns and impaired survival.

Community Attitudes About Discussing Sexual Health: Assessing Public Opinion of Local STD Prevention Campaigns

PubMed Central

Thomas, Rosalind; Bekan Homawoo, Brigitte; McClamroch, Kristi; Wise, Benjamin; Coles, F. Bruce

2013-01-01

Objectives We assessed public views about the acceptability of and need for sexually transmitted disease (STD) and sexual health-related educational messaging in local campaigns. Methods A 28-item state-added module was included in the 2008 New York Behavioral Risk Factor Surveillance System survey (n=3,751). Respondents rated acceptability of venues/dissemination channels and messaging and agreement with attitudinal/need statements. Additional data were analyzed from a separate state survey with individual county samples (n=36,257). We conducted univariate, bivariate, and multivariable modeling analyses. Results Each venue was acceptable to more than three-quarters of respondents (range: 79% for billboards to 95% for teaching STD prevention in high school). All message areas were acceptable to at least 85% of respondents (acceptability rating range: 85% to 97%). More than 70% agreed that there is a need for more open discussion about STDs. Bivariate analyses identified areas where messaging tailored to specific subgroups may be helpful (e.g., 26% of white people, 44% of African Americans, and 45% of Hispanic people agreed with the statement, “I need ideas about how to talk to my partner about protection from STDs”). Little geographic variation was seen. Results of multivariable modeling on opposition showed limited interaction effects. Conclusion These data provide key information about current community norms and reflect the public's approval for hearing and seeing more about sexual health and STDs in a range of public forums. PMID:23450887

Forgotten marriages? Measuring the reliability of marriage histories

PubMed Central

Chae, Sophia

2016-01-01

BACKGROUND Marriage histories are a valuable data source for investigating nuptiality. While researchers typically acknowledge the problems associated with their use, it is unknown to what extent these problems occur and how marriage analyses are affected. OBJECTIVE This paper seeks to investigate the quality of marriage histories by measuring levels of misreporting, examining the characteristics associated with misreporting, and assessing whether misreporting biases marriage indicators. METHODS Using data from the Malawi Longitudinal Study of Families and Health (MLSFH), I compare marriage histories reported by the same respondents at two different points in time. I investigate whether respondents consistently report their spouses (by name), status of marriage, and dates of marriage. I use multivariate regression models to investigate the characteristics associated with misreporting. Finally, I examine whether misreporting marriages and marriage dates affects marriage indicators. RESULTS Results indicate that 28.3% of men and 17.9% of women omitted at least one marriage in one of the survey waves. Multivariate regression models show that misreporting is not random: marriage, individual, interviewer, and survey characteristics are associated with marriage omission and marriage date inconsistencies. Misreporting also affects marriage indicators. CONCLUSIONS This is the first study of its kind to examine the reliability of marriage histories collected in the context of Sub-Saharan Africa. Although marriage histories are frequently used to study marriage dynamics, until now no knowledge has existed on the degree of misreporting. Misreporting in marriage histories is shown to be non-negligent and could potentially affect analyses. PMID:27152090

Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics

USGS Publications Warehouse

Pegg, Mark A.; Pierce, Clay L.

2002-01-01

Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post-impoundment period (1 October 1966–30 September 1996) for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities. 

Social and physical environmental correlates of adults' weekend sitting time and moderating effects of retirement status and physical health.

PubMed

Van Holle, Veerle; McNaughton, Sarah A; Teychenne, Megan; Timperio, Anna; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Salmon, Jo

2014-09-19

Emerging research suggests that prolonged sedentary behaviour (SB) is detrimental to health. Changes in SB patterns are likely to occur during particular life stages, for example at retirement age (55-65-year-old). Evidence on socio-ecological SB correlates is scarce and inconsistent in this age group. Moreover, the influence of socio-ecological correlates may vary depending on health and retirement status. This study examined social and environment correlates of overall weekend day sitting among adults at or approaching retirement age, and moderating effects of perceived physical health and retirement status. Baseline data from the Wellbeing, Eating and Exercise for a Long Life study in 2839 Australian adults (55-65-year-old) were analysed. Participants self-reported proximal social factors, neighbourhood social and physical environment, physical health and retirement status. MLwiN multilevel regression analyses were conducted. In the multivariable model, only social support from friends/colleagues to discourage sitting (B = -0.891; p = 0.036) was associated with overall weekend day sitting. No moderation of retirement status, nor physical health were found in the multivariable results. Results from this study suggest the importance of social factors in relation to weekend day sitting among 55-65-year-old adults. Health promotion initiatives in this age group should pay special attention to enhancing social interaction opportunities. Moreover, findings suggest that SB-specific correlates may need to be examined in future research.

Who has housing affordability problems? Disparities in Housing Cost burden by Race, Nativity and Legal Status in Los Angeles

PubMed Central

McConnell, Eileen Diaz

2013-01-01

Housing costs are a substantial component of U.S. household expenditures. Those who allocate a large proportion of their income to housing often have to make difficult financial decisions with significant short-term and long-term implications for adults and children. This study employs cross-sectional data from the first wave of the Los Angeles Family and Neighborhood Survey (L.A.FANS) collected between 2000 and 2002 to examine the most common U.S. standard of housing affordability, the likelihood of spending thirty percent or more of income on shelter costs. Multivariate analyses of a low-income sample of U.S. born Latinos, Whites, African Americans, authorized Latino immigrants and unauthorized Latino immigrants focus on baseline and persistent differences in the likelihood of being cost burdened by race, nativity and legal status. Nearly half or more of each group of low-income respondents experience housing affordability problems. The results suggest that immigrants’ legal status is the primary source of disparities among those examined, with the multivariate analyses revealing large and persistent disparities for unauthorized Latino immigrants relative to most other groups. Moreover, the higher odds of housing cost burden observed for unauthorized immigrants compared with their authorized immigrant counterparts remains substantial, accounting for traditional indicators of immigrant assimilation. These results are consistent with emerging scholarship regarding the role of legal status in shaping immigrant outcomes in the United States. PMID:24077641

Satisfaction (sexual, life, relationship, and mental health) is associated directly with penile-vaginal intercourse, but inversely with other sexual behavior frequencies.

PubMed

Brody, Stuart; Costa, Rui Miguel

2009-07-01

Some sex therapists and educators assume that many sexual behaviors provide comparable sexual satisfaction. Evidence is required to determine whether sexual behaviors differ in their associations with both sexual satisfaction and satisfaction with other aspects of life. To test the hypothesis that satisfaction with sex life, life in general, sexual partnership, and mental health correlates directly with frequency of penile-vaginal intercourse (PVI) and inversely with frequency of both masturbation and partnered sexual activity excluding PVI (noncoital sex). A representative sample of 2,810 Swedes reported frequency of PVI, noncoital sex, and masturbation during the past 30 days, and degree of satisfaction with their sex life, life in general, partnership, and mental health. Multivariate analyses (for the sexes separately and combined) considering the different satisfaction parameters as dependent variables, and the different types of sexual activities (and age) as putative predictors. For both sexes, multivariate analyses revealed that PVI frequency was directly associated with all satisfaction measures (part correlation = 0.50 with sexual satisfaction), masturbation frequency was independently inversely associated with almost all satisfaction measures, and noncoital sex frequencies independently inversely associated with some satisfaction measures (and uncorrelated with the rest). Age did not confound the results. The results are consistent with evidence that specifically PVI frequency, rather than other sexual activities, is associated with sexual satisfaction, health, and well-being. Inverse associations between satisfaction and masturbation are not due simply to insufficient PVI.

Risk factors associated with white spot syndrome virus infection in a Vietnamese rice-shrimp farming system.

PubMed

Corsin, F; Turnbull, J F; Hao, N V; Mohan, C V; Phi, T T; Phuoc, L H; Tinh, N T; Morgan, K L

2001-10-29

White spot disease (WSD) is a pandemic disease caused by a virus commonly known as white spot syndrome virus (WSSV). Several risk factors for WSD outbreaks have been suggested. However, there have been very few studies to identify risk factors for WSD outbreaks in culture systems. This paper presents and discusses the risk factors for WSSV infection identified during a longitudinal observational study conducted in a Vietnamese rice-shrimp farming system. A total of 158 variables were measured comprising location, features of the pond, management practices, pond bottom quality, shrimp health and other animals in the pond. At the end of the study period WSSV was detected in 15 of the 24 ponds followed through the production cycle (62.5%). One hundred and thirty-nine variables were used in univariate analyses. All the variables with a p-value < or = 0.10 were used in unconditional logistic regression in a forward stepwise model. An effect of location was identified in both univariate and multivariate analyses showing that ponds located in the eastern portion of the study site, closer to the sea, were more likely to test positive for WSSV by 1-step PCR at harvest. Ponds with shrimp of a smaller average size 1 mo after stocking tended to be positive for WSSV at the end of the production cycle. Average weight at 1 mo was also highlighted in multivariate analyses when considered as either a risk factor or an outcome. Other risk factors identified in univariate analyses were earlier date of stocking and use of commercial feed. A number of variables also appeared to be associated with a reduced risk of WSSV at harvest including the presence of dead post larvae in the batch sampled at stocking, presence of Hemigrapsus spp. crabs during the first month of production, feeding vitamin premix or legumes, presence of high numbers of shrimp with bacterial infection and the presence of larger mud crabs or gobies at harvest. No associations were detected with WSSV at harvest and stocking density, presence, or number or weight of wild shrimp in the pond. The multivariate model to identify outcomes associated with WSSV infection highlighted the presence of high mortality as the main variable explaining the data. The results obtained from this study are discussed in the context of WSD control and areas requiring further investigation are suggested.

The Role of Positive Alcohol Expectancies in Underage Binge Drinking Among College Students

PubMed Central

McBride, Nicole M.; Barrett, Blake; Moore, Kathleen A.; Schonfeld, Lawrence

2014-01-01

Objective This study explored associations between positive alcohol expectancies, demographics, as well as academic status and binge drinking among underage college students. Participants A sample of 1,553 underage college students at three public universities and one college in the southeast who completed the Core Alcohol and Drug Survey in the spring 2013 semester. Methods A series of bivariate analyses and logistic regression models were used to examine associations between demographic and academic status variables as well as positive alcohol expectancies with self-reported binge drinking. Positive alcohol expectancies were examined in multivariable models via two factors derived from principal component analyses. Results Students who endorsed higher agreement of these two emergent factors (Sociability; Sexuality) were more likely to report an occurrence of binge drinking in the past two weeks. Conclusions Study results document associations between positive alcohol expectancies and binge drinking among underage students; implications for prevention and treatment are discussed. PMID:24678848

Multivariate analyses of Erzgebirge granite and rhyolite composition: Implications for classification of granites and their genetic relations

USGS Publications Warehouse

Forster, H.-J.; Davis, J.C.; Tischendorf, G.; Seltmann, R.

1999-01-01

High-precision major, minor and trace element analyses for 44 elements have been made of 329 Late Variscan granitic and rhyolitic rocks from the Erzgebirge metallogenic province of Germany. The intrusive histories of some of these granites are not completely understood and exposures of rock are not adequate to resolve relationships between what apparently are different plutons. Therefore, it is necessary to turn to chemical analyses to decipher the evolution of the plutons and their relationships. A new classification of Erzgebirge plutons into five major groups of granites, based on petrologic interpretations of geochemical and mineralogical relationships (low-F biotite granites; low-F two-mica granites; high-F, high-P2O5 Li-mica granites; high-F, low-P2O5 Li-mica granites; high-F, low-P2O5 biotite granites) was tested by multivariate techniques. Canonical analyses of major elements, minor elements, trace elements and ratio variables all distinguish the groups with differing amounts of success. Univariate ANOVA's, in combination with forward-stepwise and backward-elimination canonical analyses, were used to select ten variables which were most effective in distinguishing groups. In a biplot, groups form distinct clusters roughly arranged along a quadratic path. Within groups, individual plutons tend to be arranged in patterns possibly reflecting granitic evolution. Canonical functions were used to classify samples of rhyolites of unknown association into the five groups. Another canonical analysis was based on ten elements traditionally used in petrology and which were important in the new classification of granites. Their biplot pattern is similar to that from statistically chosen variables but less effective at distinguishing the five groups of granites. This study shows that multivariate statistical techniques can provide significant insight into problems of granitic petrogenesis and may be superior to conventional procedures for petrological interpretation.

External validity of a hierarchical dimensional model of child and adolescent psychopathology: Tests using confirmatory factor analyses and multivariate behavior genetic analyses.

PubMed

Waldman, Irwin D; Poore, Holly E; van Hulle, Carol; Rathouz, Paul J; Lahey, Benjamin B

2016-11-01

Several recent studies of the hierarchical phenotypic structure of psychopathology have identified a General psychopathology factor in addition to the more expected specific Externalizing and Internalizing dimensions in both youth and adult samples and some have found relevant unique external correlates of this General factor. We used data from 1,568 twin pairs (599 MZ & 969 DZ) age 9 to 17 to test hypotheses for the underlying structure of youth psychopathology and the external validity of the higher-order factors. Psychopathology symptoms were assessed via structured interviews of caretakers and youth. We conducted phenotypic analyses of competing structural models using Confirmatory Factor Analysis and used Structural Equation Modeling and multivariate behavior genetic analyses to understand the etiology of the higher-order factors and their external validity. We found that both a General factor and specific Externalizing and Internalizing dimensions are necessary for characterizing youth psychopathology at both the phenotypic and etiologic levels, and that the 3 higher-order factors differed substantially in the magnitudes of their underlying genetic and environmental influences. Phenotypically, the specific Externalizing and Internalizing dimensions were slightly negatively correlated when a General factor was included, which reflected a significant inverse correlation between the nonshared environmental (but not genetic) influences on Internalizing and Externalizing. We estimated heritability of the general factor of psychopathology for the first time. Its moderate heritability suggests that it is not merely an artifact of measurement error but a valid construct. The General, Externalizing, and Internalizing factors differed in their relations with 3 external validity criteria: mother's smoking during pregnancy, parent's harsh discipline, and the youth's association with delinquent peers. Multivariate behavior genetic analyses supported the external validity of the 3 higher-order factors by suggesting that the General, Externalizing, and Internalizing factors were correlated with peer delinquency and parent's harsh discipline for different etiologic reasons. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Advanced multivariate analysis to assess remediation of hydrocarbons in soils.

PubMed

Lin, Deborah S; Taylor, Peter; Tibbett, Mark

2014-10-01

Accurate monitoring of degradation levels in soils is essential in order to understand and achieve complete degradation of petroleum hydrocarbons in contaminated soils. We aimed to develop the use of multivariate methods for the monitoring of biodegradation of diesel in soils and to determine if diesel contaminated soils could be remediated to a chemical composition similar to that of an uncontaminated soil. An incubation experiment was set up with three contrasting soil types. Each soil was exposed to diesel at varying stages of degradation and then analysed for key hydrocarbons throughout 161 days of incubation. Hydrocarbon distributions were analysed by Principal Coordinate Analysis and similar samples grouped by cluster analysis. Variation and differences between samples were determined using permutational multivariate analysis of variance. It was found that all soils followed trajectories approaching the chemical composition of the unpolluted soil. Some contaminated soils were no longer significantly different to that of uncontaminated soil after 161 days of incubation. The use of cluster analysis allows the assignment of a percentage chemical similarity of a diesel contaminated soil to an uncontaminated soil sample. This will aid in the monitoring of hydrocarbon contaminated sites and the establishment of potential endpoints for successful remediation.

Linear Accelerator-Based Radiosurgery Alone for Arteriovenous Malformation: More Than 12 Years of Observation

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

Matsuo, Takayuki, E-mail: takayuki@nagasaki-u.ac.jp; Kamada, Kensaku; Izumo, Tsuyoshi

Purpose: Although radiosurgery is an accepted treatment method for intracranial arteriovenous malformations (AVMs), its long-term therapeutic effects have not been sufficiently evaluated, and many reports of long-term observations are from gamma-knife facilities. Furthermore, there are few reported results of treatment using only linear accelerator (LINAC)-based radiosurgery (LBRS). Methods and Materials: Over a period of more than 12 years, we followed the long-term results of LBRS treatment performed in 51 AVM patients. Results: The actuarial obliteration rates, after a single radiosurgery session, at 3, 5, 10, and 15 years were 46.9%, 54.0%, 64.4%, and 68.0%, respectively; when subsequent radiosurgeries were included, themore » rates were 46.9%, 61.3%, 74.2%, and 90.3%, respectively. Obliteration rates were significantly related to target volumes ≥4 cm{sup 3}, marginal doses ≥12 Gy, Spetzler-Martin grades (1 vs other), and AVM scores ≥1.5; multivariate analyses revealed a significant difference for target volumes ≥4 cm{sup 3}. The postprocedural actuarial symptomatic radiation injury rates, after a single radiation surgery session, at 5, 10, and 15 years were 12.3%, 16.8%, and 19.1%, respectively. Volumes ≥4 cm{sup 3}, location (lobular or other), AVM scores ≥1.5, and the number of radiosurgery were related to radiation injury incidence; multivariate analyses revealed significant differences associated with volumes ≥4 cm{sup 3} and location (lobular or other). Conclusions: Positive results can be obtained with LBRS when performed with a target volume ≤4 cm{sup 3}, an AVM score ≤1.5, and ≥12 Gy radiation. Bleeding and radiation injuries may appear even 10 years after treatment, necessitating long-term observation.« less

The Association Between Immigration Status and Office-based Medical Provider Visits for Cancer Patients in the United States.

PubMed

Wang, Yang; Wilson, Fernando A; Chen, Li-Wu

2017-06-01

We examined differences in cancer-related office-based provider visits associated with immigration status in the United States. Data from the 2007-2012 Medical Expenditure Panel Survey and National Health Interview Survey included adult patients diagnosed with cancer. Univariate analyses described distributions of cancer-related office-based provider visits received, expenditures, visit characteristics, as well as demographic, socioeconomic, and health covariates, across immigration groups. We measured the relationships of immigrant status to number of visits and associated expenditure within the past 12 months, adjusting for age, sex, educational attainment, race/ethnicity, self-reported health status, time since cancer diagnosis, cancer remission status, marital status, poverty status, insurance status, and usual source of care. We finally performed sensitivity analyses for regression results by using the propensity score matching method to adjust for potential selection bias. Noncitizens had about 2 fewer visits in a 12-month period in comparison to US-born citizens (4.0 vs. 5.9). Total expenditure per patient was higher for US-born citizens than immigrants (not statistically significant). Noncitizens (88.3%) were more likely than US-born citizens (76.6%) to be seen by a medical doctor during a visit. Multivariate regression results showed that noncitizens had 42% lower number of visiting medical providers at office-based settings for cancer care than US-born citizens, after adjusting for all the other covariates. There were no significant differences in expenditures across immigration groups. The propensity score matching results were largely consistent with those in multivariate-adjusted regressions. Results suggest targeted interventions are needed to reduce disparities in utilization between immigrants and US-born citizen cancer patients.

Development of methodology for identification the nature of the polyphenolic extracts by FTIR associated with multivariate analysis

NASA Astrophysics Data System (ADS)

Grasel, Fábio dos Santos; Ferrão, Marco Flôres; Wolf, Carlos Rodolfo

2016-01-01

Tannins are polyphenolic compounds of complex structures formed by secondary metabolism in several plants. These polyphenolic compounds have different applications, such as drugs, anti-corrosion agents, flocculants, and tanning agents. This study analyses six different type of polyphenolic extracts by Fourier transform infrared spectroscopy (FTIR) combined with multivariate analysis. Through both principal component analysis (PCA) and hierarchical cluster analysis (HCA), we observed well-defined separation between condensed (quebracho and black wattle) and hydrolysable (valonea, chestnut, myrobalan, and tara) tannins. For hydrolysable tannins, it was also possible to observe the formation of two different subgroups between samples of chestnut and valonea and between samples of tara and myrobalan. Among all samples analysed, the chestnut and valonea showed the greatest similarity, indicating that these extracts contain equivalent chemical compositions and structure and, therefore, similar properties.

Predictors of Upper-Extremity Physical Function in Older Adults.

PubMed

Hermanussen, Hugo H; Menendez, Mariano E; Chen, Neal C; Ring, David; Vranceanu, Ana-Maria

2016-10-01

Little is known about the influence of habitual participation in physical exercise and diet on upper-extremity physical function in older adults. To assess the relationship of general physical exercise and diet to upper-extremity physical function and pain intensity in older adults. A cohort of 111 patients 50 or older completed a sociodemographic survey, the Rapid Assessment of Physical Activity (RAPA), an 11-point ordinal pain intensity scale, a Mediterranean diet questionnaire, and three Patient- Reported Outcomes Measurement Information System (PROMIS) based questionnaires: Pain Interference to measure inability to engage in activities due to pain, Upper-Extremity Physical Function, and Depression. Multivariable linear regression modeling was used to characterize the association of physical activity, diet, depression, and pain interference to pain intensity and upper-extremity function. Higher general physical activity was associated with higher PROMIS Upper-Extremity Physical Function and lower pain intensity in bivariate analyses. Adherence to the Mediterranean diet did not correlate with PROMIS Upper-Extremity Physical Function or pain intensity in bivariate analysis. In multivariable analyses factors associated with higher PROMIS Upper-Extremity Physical Function were male sex, non-traumatic diagnosis and PROMIS Pain Interference, with the latter accounting for most of the observed variability (37%). Factors associated with greater pain intensity in multivariable analyses included fewer years of education and higher PROMIS Pain Interference. General physical activity and diet do not seem to be as strongly or directly associated with upper-extremity physical function as pain interference.

Multivariate Prediction Equations for HbA1c Lowering, Weight Change, and Hypoglycemic Events Associated with Insulin Rescue Medication in Type 2 Diabetes Mellitus: Informing Economic Modeling.

PubMed

Willis, Michael; Asseburg, Christian; Nilsson, Andreas; Johnsson, Kristina; Kartman, Bernt

2017-03-01

Type 2 diabetes mellitus (T2DM) is chronic and progressive and the cost-effectiveness of new treatment interventions must be established over long time horizons. Given the limited durability of drugs, assumptions regarding downstream rescue medication can drive results. Especially for insulin, for which treatment effects and adverse events are known to depend on patient characteristics, this can be problematic for health economic evaluation involving modeling. To estimate parsimonious multivariate equations of treatment effects and hypoglycemic event risks for use in parameterizing insulin rescue therapy in model-based cost-effectiveness analysis. Clinical evidence for insulin use in T2DM was identified in PubMed and from published reviews and meta-analyses. Study and patient characteristics and treatment effects and adverse event rates were extracted and the data used to estimate parsimonious treatment effect and hypoglycemic event risk equations using multivariate regression analysis. Data from 91 studies featuring 171 usable study arms were identified, mostly for premix and basal insulin types. Multivariate prediction equations for glycated hemoglobin A 1c lowering and weight change were estimated separately for insulin-naive and insulin-experienced patients. Goodness of fit (R 2 ) for both outcomes were generally good, ranging from 0.44 to 0.84. Multivariate prediction equations for symptomatic, nocturnal, and severe hypoglycemic events were also estimated, though considerable heterogeneity in definitions limits their usefulness. Parsimonious and robust multivariate prediction equations were estimated for glycated hemoglobin A 1c and weight change, separately for insulin-naive and insulin-experienced patients. Using these in economic simulation modeling in T2DM can improve realism and flexibility in modeling insulin rescue medication. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Predictors of effects of lifestyle intervention on diabetes mellitus type 2 patients.

PubMed

Jacobsen, Ramune; Vadstrup, Eva; Røder, Michael; Frølich, Anne

2012-01-01

The main aim of the study was to identify predictors of the effects of lifestyle intervention on diabetes mellitus type 2 patients by means of multivariate analysis. Data from a previously published randomised clinical trial, which compared the effects of a rehabilitation programme including standardised education and physical training sessions in the municipality's health care centre with the same duration of individual counseling in the diabetes outpatient clinic, were used. Data from 143 diabetes patients were analysed. The merged lifestyle intervention resulted in statistically significant improvements in patients' systolic blood pressure, waist circumference, exercise capacity, glycaemic control, and some aspects of general health-related quality of life. The linear multivariate regression models explained 45% to 80% of the variance in these improvements. The baseline outcomes in accordance to the logic of the regression to the mean phenomenon were the only statistically significant and robust predictors in all regression models. These results are important from a clinical point of view as they highlight the more urgent need for and better outcomes following lifestyle intervention for those patients who have worse general and disease-specific health.

Association between sleep difficulties as well as duration and hypertension: is BMI a mediator?

PubMed

Carrillo-Larco, R M; Bernabe-Ortiz, A; Sacksteder, K A; Diez-Canseco, F; Cárdenas, M K; Gilman, R H; Miranda, J J

2017-01-01

Sleep difficulties and short sleep duration have been associated with hypertension. Though body mass index (BMI) may be a mediator variable, the mediation effect has not been defined. We aimed to assess the association between sleep duration and sleep difficulties with hypertension, to determine if BMI is a mediator variable, and to quantify the mediation effect. We conducted a mediation analysis and calculated prevalence ratios with 95% confidence intervals. The exposure variables were sleep duration and sleep difficulties, and the outcome was hypertension. Sleep difficulties were statistically significantly associated with a 43% higher prevalence of hypertension in multivariable analyses; results were not statistically significant for sleep duration. In these analyses, and in sex-specific subgroup analyses, we found no strong evidence that BMI mediated the association between sleep indices and risk of hypertension. Our findings suggest that BMI does not appear to mediate the association between sleep patterns and hypertension. These results highlight the need to further study the mechanisms underlying the relationship between sleep patterns and cardiovascular risk factors.

Two time-series analyses of the impact of antibiotic consumption and alcohol-based hand disinfection on the incidences of nosocomial methicillin-resistant Staphylococcus aureus infection and Clostridium difficile infection.

PubMed

Kaier, Klaus; Hagist, Christian; Frank, Uwe; Conrad, Andreas; Meyer, Elisabeth

2009-04-01

To determine the impact of antibiotic consumption and alcohol-based hand disinfection on the incidences of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection and Clostridium difficile infection (CDI). Two multivariate time-series analyses were performed that used as dependent variables the monthly incidences of nosocomial MRSA infection and CDI at the Freiburg University Medical Center during the period January 2003 through October 2007. The volume of alcohol-based hand rub solution used per month was quantified in liters per 1,000 patient-days. Antibiotic consumption was calculated in terms of the number of defined daily doses per 1,000 patient-days per month. The use of alcohol-based hand rub was found to have a significant impact on the incidence of nosocomial MRSA infection (P< .001). The multivariate analysis (R2=0.66) showed that a higher volume of use of alcohol-based hand rub was associated with a lower incidence of nosocomial MRSA infection. Conversely, a higher level of consumption of selected antimicrobial agents was associated with a higher incidence of nosocomial MRSA infection. This analysis showed this relationship was the same for the use of second-generation cephalosporins (P= .023), third-generation cephalosporins (P= .05), fluoroquinolones (P= .01), and lincosamides (P= .05). The multivariate analysis (R2=0.55) showed that a higher level of consumption of third-generation cephalosporins (P= .008), fluoroquinolones (P= .084), and/or macrolides (P= .007) was associated with a higher incidence of CDI. A correlation with use of alcohol-based hand rub was not detected. In 2 multivariate time-series analyses, we were able to show the impact of hand hygiene and antibiotic use on the incidence of nosocomial MRSA infection, but we found no association between hand hygiene and incidence of CDI.

On the potential for the Partial Triadic Analysis to grasp the spatio-temporal variability of groundwater hydrochemistry

NASA Astrophysics Data System (ADS)

Gourdol, L.; Hissler, C.; Pfister, L.

2012-04-01

The Luxembourg sandstone aquifer is of major relevance for the national supply of drinking water in Luxembourg. The city of Luxembourg (20% of the country's population) gets almost 2/3 of its drinking water from this aquifer. As a consequence, the study of both the groundwater hydrochemistry, as well as its spatial and temporal variations, are considered as of highest priority. Since 2005, a monitoring network has been implemented by the Water Department of Luxembourg City, with a view to a more sustainable management of this strategic water resource. The data collected to date forms a large and complex dataset, describing spatial and temporal variations of many hydrochemical parameters. The data treatment issue is tightly connected to this kind of water monitoring programs and complex databases. Standard multivariate statistical techniques, such as principal components analysis and hierarchical cluster analysis, have been widely used as unbiased methods for extracting meaningful information from groundwater quality data and are now classically used in many hydrogeological studies, in particular to characterize temporal or spatial hydrochemical variations induced by natural and anthropogenic factors. But these classical multivariate methods deal with two-way matrices, usually parameters/sites or parameters/time, while often the dataset resulting from qualitative water monitoring programs should be seen as a datacube parameters/sites/time. Three-way matrices, such as the one we propose here, are difficult to handle and to analyse by classical multivariate statistical tools and thus should be treated with approaches dealing with three-way data structures. One possible analysis approach consists in the use of partial triadic analysis (PTA). The PTA was previously used with success in many ecological studies but never to date in the domain of hydrogeology. Applied to the dataset of the Luxembourg Sandstone aquifer, the PTA appears as a new promising statistical instrument for hydrogeologists, in particular to characterize temporal and spatial hydrochemical variations induced by natural and anthropogenic factors. This new approach for groundwater management offers potential for 1) identifying a common multivariate spatial structure, 2) untapping the different hydrochemical patterns and explaining their controlling factors and 3) analysing the temporal variability of this structure and grasping hydrochemical changes.

An improved method for bivariate meta-analysis when within-study correlations are unknown.

PubMed

Hong, Chuan; D Riley, Richard; Chen, Yong

2018-03-01

Multivariate meta-analysis, which jointly analyzes multiple and possibly correlated outcomes in a single analysis, is becoming increasingly popular in recent years. An attractive feature of the multivariate meta-analysis is its ability to account for the dependence between multiple estimates from the same study. However, standard inference procedures for multivariate meta-analysis require the knowledge of within-study correlations, which are usually unavailable. This limits standard inference approaches in practice. Riley et al proposed a working model and an overall synthesis correlation parameter to account for the marginal correlation between outcomes, where the only data needed are those required for a separate univariate random-effects meta-analysis. As within-study correlations are not required, the Riley method is applicable to a wide variety of evidence synthesis situations. However, the standard variance estimator of the Riley method is not entirely correct under many important settings. As a consequence, the coverage of a function of pooled estimates may not reach the nominal level even when the number of studies in the multivariate meta-analysis is large. In this paper, we improve the Riley method by proposing a robust variance estimator, which is asymptotically correct even when the model is misspecified (ie, when the likelihood function is incorrect). Simulation studies of a bivariate meta-analysis, in a variety of settings, show a function of pooled estimates has improved performance when using the proposed robust variance estimator. In terms of individual pooled estimates themselves, the standard variance estimator and robust variance estimator give similar results to the original method, with appropriate coverage. The proposed robust variance estimator performs well when the number of studies is relatively large. Therefore, we recommend the use of the robust method for meta-analyses with a relatively large number of studies (eg, m≥50). When the sample size is relatively small, we recommend the use of the robust method under the working independence assumption. We illustrate the proposed method through 2 meta-analyses. Copyright © 2017 John Wiley & Sons, Ltd.

High protein and cholesterol intakes associated with emergence of glucose intolerance in a low-risk Canadian Inuit population.

PubMed

Sefidbakht, Saghar; Johnson-Down, Louise; Young, T Kue; Egeland, Grace M

2016-07-01

The rate of type 2 diabetes mellitus among Inuit is 12·2 % in individuals over 50 years of age, similar to the Canadian prevalence. Given marked dietary transitions in the Arctic, we evaluated the dietary and other correlates of not previously diagnosed glucose intolerance, defined as type 2 diabetes mellitus, impaired fasting glucose or impaired glucose tolerance. Cross-sectional analyses were limited to adults with a completed 2 h oral glucose tolerance test and without pre-existing diabetes. Anthropometric assessments, health and medication usage questionnaires and a 24 h dietary recall were administered. Canadian International Polar Year Inuit Health Survey (2007-2008). Inuit adults (n 777). Glucose intolerance was associated with older age and adiposity. Percentage of energy from protein above the Acceptable Macronutrient Distribution Range of 35 %, compared with intake within the range, was associated with increased odds of glucose intolerance (OR=1·98; 95 % CI 1·09, 3·61) in multivariable analyses. Further, cholesterol intake in the highest three quartiles combined (median exposures of 207, 416 and 778 mg/d, respectively) compared with the lowest quartile (median intake of 81 mg/d) was associated with glucose intolerance (OR=2·15; 95 % CI 1·23, 3·78) in multivariable analyses. Past-day traditional food consumption was borderline protective of glucose intolerance (P=0·054) and high fibre intake was not significantly protective (P=0·08). The results contribute to the existing literature on high protein and cholesterol intakes as they may relate to diabetes risk.

Low bone mineral density and risk of incident fracture in HIV-infected adults.

PubMed

Battalora, Linda; Buchacz, Kate; Armon, Carl; Overton, Edgar T; Hammer, John; Patel, Pragna; Chmiel, Joan S; Wood, Kathy; Bush, Timothy J; Spear, John R; Brooks, John T; Young, Benjamin

2016-01-01

Prevalence rates of low bone mineral density (BMD) and bone fractures are higher among HIV-infected adults compared with the general United States (US) population, but the relationship between BMD and incident fractures in HIV-infected persons has not been well described. Dual energy X-ray absorptiometry (DXA) results of the femoral neck of the hip and clinical data were obtained prospectively during 2004-2012 from participants in two HIV cohort studies. Low BMD was defined by a T-score in the interval >-2.5 to <-1.0 (osteopenia) or ≤-2.5 (osteoporosis). We analysed the association of low BMD with risk of subsequent incident fractures, adjusted for sociodemographics, other risk factors and covariables, using multivariable proportional hazards regression. Among 1,006 participants analysed (median age 43 years [IQR 36-49], 83% male, 67% non-Hispanic white, median CD4(+) T-cell count 461 cells/mm(3) [IQR 311-658]), 36% (n=358) had osteopenia and 4% (n=37) osteoporosis; 67 had a prior fracture documented. During 4,068 person-years of observation after DXA scanning, 85 incident fractures occurred, predominantly rib/sternum (n=18), hand (n=14), foot (n=13) and wrist (n=11). In multivariable analyses, osteoporosis (adjusted hazard ratio [aHR] 4.02, 95% CI 2.02, 8.01) and current/prior tobacco use (aHR 1.59, 95% CI 1.02, 2.50) were associated with incident fracture. In this large sample of HIV-infected adults in the US, low baseline BMD was significantly associated with elevated risk of incident fracture. There is potential value of DXA screening in this population.

Bad nights or bad bars? Multi-level analysis of environmental predictors of aggression in late-night large-capacity bars and clubs.

PubMed

Graham, Kathryn; Bernards, Sharon; Osgood, D Wayne; Wells, Samantha

2006-11-01

To clarify environmental predictors of bar-room aggression by differentiating relationships due to nightly variations versus across bar variations, frequency versus severity of aggression and patron versus staff aggression. Male-female pairs of researcher-observers conducted 1334 observations in 118 large capacity (> 300) bars and clubs in Toronto, Canada. Observers independently rated aspects of the environment (e.g. crowding) at every visit and wrote detailed narratives of each incident of aggression that occurred. Measures of severity of aggression for the visit were calculated by aggregating ratings for each person in aggressive incidents. Although bivariate analyses confirmed the significance of most environmental predictors of aggression identified in previous research, multivariate analyses identified the following key visit-level predictors (controlling for bar-level relationships): rowdiness/permissive environment and people hanging around after closing predicted both frequency and severity of aggression; sexual activity, contact and competition and people with two or more drinks at closing predicted frequency but not severity of aggression; lack of staff monitoring predicted more severe patron aggression, while having more and better coordinated staff predicted more severe staff aggression. Intoxication of patrons was significantly associated with more frequent and severe patron aggression at the bar level (but not at the visit level) in the multivariate analyses and negatively associated with severity of staff aggression at the visit level. The results demonstrate clearly the importance of the immediate environment (not just the type of bar or characteristics of usual patrons) and the importance of specific environmental factors, including staff behaviour, in predicting both frequency and severity of aggression.

Social networks and inflammatory markers in the Framingham Heart Study.

PubMed

Loucks, Eric B; Sullivan, Lisa M; D'Agostino, Ralph B; Larson, Martin G; Berkman, Lisa F; Benjamin, Emelia J

2006-11-01

Lack of social integration predicts coronary heart disease mortality in prospective studies; however, the biological pathways that may be responsible are poorly understood. The specific aims of this study were to examine whether social networks are associated with serum concentrations of the inflammatory markers interleukin-6 (IL-6), C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1). Participants in the Framingham Study attending examinations from 1998 to 2001 (n=3267) were eligible for inclusion in the study. Social networks were assessed using the Berkman-Syme Social Network Index (SNI). Concentrations of IL-6, CRP, sICAM-1 and MCP-1 were measured in fasting serum samples. Multivariable linear regression analyses were used to assess the association of social networks with inflammatory markers adjusting for potential confounders including age, smoking, blood pressure, total:HDL cholesterol ratio, body mass index, lipid-lowering and antihypertensive medication, diabetes, cardiovascular disease, depression and socioeconomic status. Results found that the SNI was significantly inversely associated with IL-6 in men (p=0.03) after adjusting for potential confounders. In age-adjusted analyses, social networks also were significantly inversely associated with IL-6 for women (p=0.03) and were marginally to modestly associated with CRP and sICAM-1 for men (p=0.08 and 0.02, respectively), but these associations were not significant in the multivariate analyses. In conclusion, social networks were found to be inversely associated with interleukin-6 levels in men. The possibility that inflammatory markers may be potential mediators between social integration and coronary heart disease merits further investigation.

The Religiosity/Spirituality of Latina Breast Cancer Survivors and Influence on Health-Related Quality of Life

PubMed Central

Wildes, Kimberly A.; Miller, Alexander R.; de Majors, Sandra San Miguel; Ramirez, Amelie G.

2010-01-01

Objective The study evaluated the association of religiosity/spirituality (R/S) and health-related quality of life (HRQOL) among Latina breast cancer survivors (BCS) in order to determine whether R/S would be positively correlated with HRQOL and whether R/S would significantly influence HRQOL. Methods The cross-sectional study utilized self-report data from 117 Latina BCS survivors. R/S was measured with the Systems of Belief Inventory - 15 Revised (SBI-15R) and HRQOL was measured with the Functional Assessment of Cancer Therapy – General (FACT-G). Analyses included calculation of descriptive statistics, t-tests, bivariate correlations, and multivariate analyses. Results Latina BCS had very high levels of R/S and generally good HRQOL. The SBI-15R total score was positively correlated with FACT-G social well-being (r=0.266, p=0.005), relationship with doctor (r=0.219, p=0.020), and functional well-being (r=0.216, p=0.022). Multivariate analyses revealed that SBI-15R was a significant predictor of FACT-G functional well-being (p=0.041) and satisfaction with the relationship with the doctor (p=0.050), where higher levels of R/S predicted higher levels of well-being. Conclusions Latina BCS had very high levels of R/S, which were significantly, positively correlated with dimensions of HRQOL (social well-being, functional well-being, relationship with doctor). Further, these high levels of R/S predicted better functional well-being and satisfaction with the patient-doctor relationship while controlling for potentially confounding variables. Implications are discussed. PMID:19034922

Genetic parameters for growth characteristics of free-range chickens under univariate random regression models.

PubMed

Rovadoscki, Gregori A; Petrini, Juliana; Ramirez-Diaz, Johanna; Pertile, Simone F N; Pertille, Fábio; Salvian, Mayara; Iung, Laiza H S; Rodriguez, Mary Ana P; Zampar, Aline; Gaya, Leila G; Carvalho, Rachel S B; Coelho, Antonio A D; Savino, Vicente J M; Coutinho, Luiz L; Mourão, Gerson B

2016-09-01

Repeated measures from the same individual have been analyzed by using repeatability and finite dimension models under univariate or multivariate analyses. However, in the last decade, the use of random regression models for genetic studies with longitudinal data have become more common. Thus, the aim of this research was to estimate genetic parameters for body weight of four experimental chicken lines by using univariate random regression models. Body weight data from hatching to 84 days of age (n = 34,730) from four experimental free-range chicken lines (7P, Caipirão da ESALQ, Caipirinha da ESALQ and Carijó Barbado) were used. The analysis model included the fixed effects of contemporary group (gender and rearing system), fixed regression coefficients for age at measurement, and random regression coefficients for permanent environmental effects and additive genetic effects. Heterogeneous variances for residual effects were considered, and one residual variance was assigned for each of six subclasses of age at measurement. Random regression curves were modeled by using Legendre polynomials of the second and third orders, with the best model chosen based on the Akaike Information Criterion, Bayesian Information Criterion, and restricted maximum likelihood. Multivariate analyses under the same animal mixed model were also performed for the validation of the random regression models. The Legendre polynomials of second order were better for describing the growth curves of the lines studied. Moderate to high heritabilities (h(2) = 0.15 to 0.98) were estimated for body weight between one and 84 days of age, suggesting that selection for body weight at all ages can be used as a selection criteria. Genetic correlations among body weight records obtained through multivariate analyses ranged from 0.18 to 0.96, 0.12 to 0.89, 0.06 to 0.96, and 0.28 to 0.96 in 7P, Caipirão da ESALQ, Caipirinha da ESALQ, and Carijó Barbado chicken lines, respectively. Results indicate that genetic gain for body weight can be achieved by selection. Also, selection for body weight at 42 days of age can be maintained as a selection criterion. © 2016 Poultry Science Association Inc.

Inhalant Use, Inhalant-Use Disorders, and Antisocial Behavior: Findings From the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)*

PubMed Central

Howard, Matthew O.; Perron, Brian E.; Vaughn, Michael G.; Bender, Kimberly A.; Garland, Eric

2010-01-01

Objective: Few studies have explored the topography of antisocial behavior in a nationally representative sample of inhalant users. We examined (a) the lifetime prevalence of 20 childhood and adult antisocial behaviors in inhalant users with inhalant-use disorders (IUD+) and without IUDs (IUD−); (b) the nature and strength of associations between inhalant use, IUDs, and specific antisocial behaviors in multi-variate analyses; and (c) the relationships between inhalant use, IUDs, and antisocial behaviors in a national sample of adults with antisocial personality disorder. Method: The National Epidemiologic Survey on Alcohol and Related Conditions was a multistage national survey of 43,093 U.S. residents. Respondents completed a structured psychiatric interview. Results: IUD+ and IUD− respondents were significantly younger and more likely to be unemployed, to be male, to have never married, and to report family and personal histories of alcohol and drug problems than inhalant nonusers. Family histories of alcohol problems and personal histories of drug problems were significantly more prevalent among IUD+ respondents, compared with IUD− respondents. In bivariate analyses, IUD+ and IUD− respondents evidenced significantly higher lifetime levels of all childhood and adult antisocial behaviors than inhalant nonusers. IUD+ respondents were significantly more likely than their IUD− counterparts to report bullying behavior, starting physical fights, using dangerous weapons, physical cruelty to people, staying out all night without permission, running away, and frequent truancy in childhood, as well as greater deceitfulness, impulsivity, irritability/aggressiveness, recklessness, and irresponsibility in adulthood. Multivari-ate analyses indicated that IUD+ respondents had a significantly elevated risk for childhood and adult antisocial behaviors, compared with inhalant nonusers, with the strongest effects for using dangerous weapons, physical cruelty to animals, and physical cruelty to people. Similarly, IUD+ respondents differed significantly from their IUD− counterparts primarily across measures of interpersonal violence. Among persons with antisocial personality disorder, inhalant use and IUDs were associated with greater antisocial behavior, albeit with fewer and weaker effects. Conclusions: Respondents with IUDs had pervasively elevated levels of antisocial conduct, including diverse forms of early-onset and inter-personally violent behavior. PMID:20230717

A new lizard species of the Phymaturus patagonicus group (Squamata: Liolaemini) from northern Patagonia, Neuquén, Argentina.

PubMed

Marín, Andrea González; Pérez, Cristian Hernán Fulvio; Minoli, Ignacio; Morando, Mariana; Avila, Luciano Javier

2016-06-10

The integrative taxonomy framework allows developing robust hypotheses of species limits based on the integration of results from different data sets and analytical methods. In this work, we test a candidate species hypothesis previously suggested based on molecular data, with geometric and traditional morphometrics analyses (multivariate and univariate). This new lizard species is part of the Phymaturus patagonicus group (payuniae clade) that is distributed in Neuquén and Mendoza provinces (Argentina). Our results showed that Phymaturus rahuensis sp. nov. differs from the other species of the payuniae clade by a higher number of midbody scales, and fewer supralabials scales, finger lamellae and toe lamellae. Also, its multidimensional spaces, both based on continuous lineal variables and geometric morphometrics (shape) characters, do not overlap with those of the other species in this clade. The results of the morphometric and geometric morphometric analyses presented here, coupled with previously published molecular data, represent three independent lines of evidence that support the diagnosis of this new taxon.

Association between cardiovascular risk factors and carotid intima-media thickness in prepubertal Brazilian children.

PubMed

Gazolla, Fernanda Mussi; Neves Bordallo, Maria Alice; Madeira, Isabel Rey; de Miranda Carvalho, Cecilia Noronha; Vieira Monteiro, Alexandra Maria; Pinheiro Rodrigues, Nádia Cristina; Borges, Marcos Antonio; Collett-Solberg, Paulo Ferrez; Muniz, Bruna Moreira; de Oliveira, Cecilia Lacroix; Pinheiro, Suellen Martins; de Queiroz Ribeiro, Rebeca Mathias

2015-05-01

Early exposure to cardiovascular risk factors creates a chronic inflammatory state that could damage the endothelium followed by thickening of the carotid intima-media. To investigate the association of cardiovascular risk factors and thickening of the carotid intima. Media in prepubertal children. In this cross-sectional study, carotid intima-media thickness (cIMT) and cardiovascular risk factors were assessed in 129 prepubertal children aged from 5 to 10 year. Association was assessed by simple and multivariate logistic regression analyses. In simple logistic regression analyses, body mass index (BMI) z-score, waist circumference, and systolic blood pressure (SBP) were positively associated with increased left, right, and average cIMT, whereas diastolic blood pressure was positively associated only with increased left and average cIMT (p<0.05). In multivariate logistic regression analyses increased left cIMT was positively associated to BMI z-score and SBP, and increased average cIMT was only positively associated to SBP (p<0.05). BMI z-score and SBP were the strongest risk factors for increased cIMT.

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.

Social support network characteristics and sexual risk taking among a racially/ethnically diverse sample of young, urban men who have sex with men

PubMed Central

Kapadia, F; Siconolfi, DE; Barton, S; Olivieri, B; Lombardo, L; Halkitis, PN

2013-01-01

Associations between social support network characteristics and sexual risk among racially/ethnically diverse young men who have sex with men (YMSM) were examined using egocentric network data from a prospective cohort study of YMSM (n=501) recruited in New York City. Bivariate and multivariable logistic regression analyses examined associations between social support network characteristics and sexual risk taking behaviors in Black, Hispanic/Latino, and White YMSM. Bivariate analyses indicated key differences in network size, composition, communication frequency and average relationship duration by race/ethnicity. In multivariable analyses, controlling for individual level sociodemographic, psychosocial and relationship factors, having a sexual partner in one’s social support network was associated with unprotected sexual behavior for both Hispanic/Latino (AOR=3.90) and White YMSM (AOR=4.93). Further examination of key network characteristics across racial/ethnic groups are warranted in order to better understand the extant mechanisms for provision of HIV prevention programming to racially/ethnically diverse YMSM at risk for HIV. PMID:23553346

Permutation Tests of Hierarchical Cluster Analyses of Carrion Communities and Their Potential Use in Forensic Entomology.

PubMed

van der Ham, Joris L

2016-05-19

Forensic entomologists can use carrion communities' ecological succession data to estimate the postmortem interval (PMI). Permutation tests of hierarchical cluster analyses of these data provide a conceptual method to estimate part of the PMI, the post-colonization interval (post-CI). This multivariate approach produces a baseline of statistically distinct clusters that reflect changes in the carrion community composition during the decomposition process. Carrion community samples of unknown post-CIs are compared with these baseline clusters to estimate the post-CI. In this short communication, I use data from previously published studies to demonstrate the conceptual feasibility of this multivariate approach. Analyses of these data produce series of significantly distinct clusters, which represent carrion communities during 1- to 20-day periods of the decomposition process. For 33 carrion community samples, collected over an 11-day period, this approach correctly estimated the post-CI within an average range of 3.1 days. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stem cell-associated genes are extremely poor prognostic factors for soft-tissue sarcoma patients.

PubMed

Taubert, H; Würl, P; Greither, T; Kappler, M; Bache, M; Bartel, F; Kehlen, A; Lautenschläger, C; Harris, L C; Kaushal, D; Füssel, S; Meye, A; Böhnke, A; Schmidt, H; Holzhausen, H-J; Hauptmann, S

2007-11-01

Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it is still difficult to detect and isolate cancer stem cells. An alternative approach is to analyse stem cell-associated gene expression. We investigated the coexpression of three stem cell-associated genes, Hiwi, hTERT and survivin, by quantitative real-time-PCR in 104 primary soft-tissue sarcomas (STS). Multivariate Cox's proportional hazards regression analyses allowed correlating gene expression with overall survival for STS patients. Coexpression of all three stem cell-associated genes resulted in a significantly increased risk of tumor-related death. Importantly, tumors of patients with the poorest prognosis were of all four tumor stages, suggesting that their risk is based upon coexpression of stem cell-associated genes rather than on tumor stage.

Performance of the disease risk score in a cohort study with policy-induced selection bias.

PubMed

Tadrous, Mina; Mamdani, Muhammad M; Juurlink, David N; Krahn, Murray D; Lévesque, Linda E; Cadarette, Suzanne M

2015-11-01

To examine the performance of the disease risk score (DRS) in a cohort study with evidence of policy-induced selection bias. We examined two cohorts of new users of bisphosphonates. Estimates for 1-year hip fracture rates between agents using DRS, exposure propensity scores and traditional multivariable analysis were compared. The results for the cohort with no evidence of policy-induced selection bias showed little variation across analyses (-4.1-2.0%). Analysis of the cohort with evidence of policy-induced selection bias showed greater variation (-13.5-8.1%), with the greatest difference seen with DRS analyses. Our findings suggest that caution may be warranted when using DRS methods in cohort studies with policy-induced selection bias, further research is needed.

A study of the comparative effects of various means of motion cueing during a simulated compensatory tracking task

NASA Technical Reports Server (NTRS)

Mckissick, B. T.; Ashworth, B. R.; Parrish, R. V.; Martin, D. J., Jr.

1980-01-01

NASA's Langley Research Center conducted a simulation experiment to ascertain the comparative effects of motion cues (combinations of platform motion and g-seat normal acceleration cues) on compensatory tracking performance. In the experiment, a full six-degree-of-freedom YF-16 model was used as the simulated pursuit aircraft. The Langley Visual Motion Simulator (with in-house developed wash-out), and a Langley developed g-seat were principal components of the simulation. The results of the experiment were examined utilizing univariate and multivariate techniques. The statistical analyses demonstrate that the platform motion and g-seat cues provide additional information to the pilot that allows substantial reduction of lateral tracking error. Also, the analyses show that the g-seat cue helps reduce vertical error.

Application of multivariate statistical techniques in microbial ecology

PubMed Central

Paliy, O.; Shankar, V.

2016-01-01

Recent advances in high-throughput methods of molecular analyses have led to an explosion of studies generating large scale ecological datasets. Especially noticeable effect has been attained in the field of microbial ecology, where new experimental approaches provided in-depth assessments of the composition, functions, and dynamic changes of complex microbial communities. Because even a single high-throughput experiment produces large amounts of data, powerful statistical techniques of multivariate analysis are well suited to analyze and interpret these datasets. Many different multivariate techniques are available, and often it is not clear which method should be applied to a particular dataset. In this review we describe and compare the most widely used multivariate statistical techniques including exploratory, interpretive, and discriminatory procedures. We consider several important limitations and assumptions of these methods, and we present examples of how these approaches have been utilized in recent studies to provide insight into the ecology of the microbial world. Finally, we offer suggestions for the selection of appropriate methods based on the research question and dataset structure. PMID:26786791

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.

The influence of television and video game use on attention and school problems: a multivariate analysis with other risk factors controlled.

PubMed

Ferguson, Christopher J

2011-06-01

Research on youth mental health has increasingly indicated the importance of multivariate analyses of multiple risk factors for negative outcomes. Television and video game use have often been posited as potential contributors to attention problems, but previous studies have not always been well-controlled or used well-validated outcome measures. The current study examines the multivariate nature of risk factors for attention problems symptomatic of attention deficit hyperactivity disorder and poor school performance. A predominantly Hispanic population of 603 children (ages 10-14) and their parents/guardians responded to multiple behavioral measures. Outcome measures included parent and child reported attention problem behaviors on the Child Behavior Checklist (CBCL) as well as poor school performance as measured by grade point average (GPA). Results found that internal factors such as male gender, antisocial traits, family environment and anxiety best predicted attention problems. School performance was best predicted by family income. Television and video game use, whether total time spent using, or exposure to violent content specifically, did not predict attention problems or GPA. Television and video game use do not appear to be significant predictors of childhood attention problems. Intervention and prevention efforts may be better spent on other risk factors. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mentorship Programs in Radiation Oncology Residency Training Programs: A Critical Unmet Need

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

Dhami, Gurleen; Gao, Wendy; Gensheimer, Michael F.

Purpose: To conduct a nationwide survey to evaluate the current status of resident mentorship in radiation oncology. Methods and Materials: An anonymous electronic questionnaire was sent to all residents and recent graduates at US Accreditation Council for Graduate Medical Education–accredited radiation oncology residency programs, identified in the member directory of the Association of Residents in Radiation Oncology. Factors predictive of having a mentor and satisfaction with the mentorship experience were identified using univariate and multivariate analyses. Results: The survey response rate was 25%, with 85% of respondents reporting that mentorship plays a critical role in residency training, whereas only 53%more » had a current mentor. Larger programs (≥10 faculty, P=.004; and ≥10 residents, P<.001) were more likely to offer a formal mentorship program, which makes it more likely for residents to have an active mentor (88% vs 44%). Residents in a formal mentoring program reported being more satisfied with the overall mentorship experience (univariate odds ratio 8.77, P<.001; multivariate odds ratio 5, P<.001). On multivariate analysis, women were less likely to be satisfied with the mentorship experience. Conclusions: This is the first survey focusing on the status of residency mentorship in radiation oncology. Our survey highlights the unmet need for mentorship in residency programs.« less

Redo surgery risk in patients with cardiac prosthetic valve dysfunction

PubMed Central

Maciejewski, Marek; Piestrzeniewicz, Katarzyna; Bielecka-Dąbrowa, Agata; Piechowiak, Monika; Jaszewski, Ryszard

2011-01-01

Introduction The aim of the study was to analyse the risk factors of early and late mortality in patients undergoing the first reoperation for prosthetic valve dysfunction. Material and methods A retrospective observational study was performed in 194 consecutive patients (M = 75, F = 119; mean age 53.2 ±11 years) with a mechanical prosthetic valve (n = 103 cases; 53%) or bioprosthesis (91; 47%). Univariate and multivariate Cox statistical analysis was performed to determine risk factors of early and late mortality. Results The overall early mortality was 18.6%: 31.4% in patients with symptoms of NYHA functional class III-IV and 3.4% in pts in NYHA class I-II. Multivariate analysis identified symptoms of NYHA class III-IV and endocarditis as independent predictors of early mortality. The overall late mortality (> 30 days) was 8.2% (0.62% year/patient). Multivariate analysis identified age at the time of reoperation as a strong independent predictor of late mortality. Conclusions Reoperation in patients with prosthetic valves, performed urgently, especially in patients with symptoms of NYHA class III-IV or in the case of endocarditis, bears a high mortality rate. Risk of planned reoperation, mostly in patients with symptoms of NYHA class I-II, does not differ from the risk of the first operation. PMID:22291767

A Multivariate Analysis of the Early Dropout Process

ERIC Educational Resources Information Center

Fiester, Alan R.; Rudestam, Kjell E.

1975-01-01

Principal-component factor analyses were performed on patient input (demographic and pretherapy expectations), therapist input (demographic), and patient perspective therapy process variables that significantly differentiated early dropout from nondropout outpatients at two community mental health centers. (Author)

Development of a multivariate model to predict the likelihood of carcinoma in patients with indeterminate peripheral lung nodules after a nondiagnostic bronchoscopic evaluation.

PubMed

Voss, Jesse S; Iqbal, Seher; Jenkins, Sarah M; Henry, Michael R; Clayton, Amy C; Jett, James R; Kipp, Benjamin R; Halling, Kevin C; Maldonado, Fabien

2014-01-01

Studies have shown that fluorescence in situ hybridization (FISH) testing increases lung cancer detection on cytology specimens in peripheral nodules. The goal of this study was to determine whether a predictive model using clinical features and routine cytology with FISH results could predict lung malignancy after a nondiagnostic bronchoscopic evaluation. Patients with an indeterminate peripheral lung nodule that had a nondiagnostic bronchoscopic evaluation were included in this study (N = 220). FISH was performed on residual bronchial brushing cytology specimens diagnosed as negative (n = 195), atypical (n = 16), or suspicious (n = 9). FISH results included hypertetrasomy (n = 30) and negative (n = 190). Primary study end points included lung cancer status along with time to diagnosis of lung cancer or date of last clinical follow-up. Hazard ratios (HRs) were calculated using Cox proportional hazards regression model analyses, and P values < .05 were considered statistically significant. The mean age of the 220 patients was 66.7 years (range, 35-91), and most (58%) were men. Most patients (79%) were current or former smokers with a mean pack year history of 43.2 years (median, 40; range, 1-200). After multivariate analysis, hypertetrasomy FISH (HR = 2.96, P < .001), pack years (HR = 1.03 per pack year up to 50, P = .001), age (HR = 1.04 per year, P = .02), atypical or suspicious cytology (HR = 2.02, P = .04), and nodule spiculation (HR = 2.36, P = .003) were independent predictors of malignancy over time and were used to create a prediction model (C-statistic = 0.78). These results suggest that this multivariate model including test results and clinical features may be useful following a nondiagnostic bronchoscopic examination. © 2013.

Behavioral and Psychosocial Correlates of HIV Testing Among Male Clients of Female Sex Workers in Tijuana, Mexico.

PubMed

Fleming, Paul J; Patterson, Thomas L; Chavarin, Claudia V; Semple, Shirley J; Magis-Rodriguez, Carlos; Pitpitan, Eileen V

2017-08-01

We use data collected from a sample of 400 male clients of female sex workers (FSW) to examine their HIV testing behavior. We present frequencies of HIV testing and used bivariate and multivariable analyses to assess its socio-demographic, behavioral, and psychosocial correlates. We found that the majority (55 %) of male clients of FSW in Tijuana, Mexico had never had an HIV test and the prevalence of HIV testing within the past year was low (9 %). In multivariable analyses, significant correlates of having ever tested for HIV were higher age, higher HIV knowledge score, lower sexual compulsiveness score, lower misogynistic attitudes score, having a condom break during sex with a FSW, and higher frequency of sex with a FSW while she was high. Our findings represent an important starting point for developing effective interventions to address the need to promote HIV testing among this population.

imDEV: a graphical user interface to R multivariate analysis tools in Microsoft Excel.

PubMed

Grapov, Dmitry; Newman, John W

2012-09-01

Interactive modules for Data Exploration and Visualization (imDEV) is a Microsoft Excel spreadsheet embedded application providing an integrated environment for the analysis of omics data through a user-friendly interface. Individual modules enables interactive and dynamic analyses of large data by interfacing R's multivariate statistics and highly customizable visualizations with the spreadsheet environment, aiding robust inferences and generating information-rich data visualizations. This tool provides access to multiple comparisons with false discovery correction, hierarchical clustering, principal and independent component analyses, partial least squares regression and discriminant analysis, through an intuitive interface for creating high-quality two- and a three-dimensional visualizations including scatter plot matrices, distribution plots, dendrograms, heat maps, biplots, trellis biplots and correlation networks. Freely available for download at http://sourceforge.net/projects/imdev/. Implemented in R and VBA and supported by Microsoft Excel (2003, 2007 and 2010).

Motivations for genetic testing for lung cancer risk among young smokers.

PubMed

O'Neill, Suzanne C; Lipkus, Isaac M; Sanderson, Saskia C; Shepperd, James; Docherty, Sharron; McBride, Colleen M

2013-11-01

To examine why young people might want to undergo genetic susceptibility testing for lung cancer despite knowing that tested gene variants are associated with small increases in disease risk. The authors used a mixed-method approach to evaluate motives for and against genetic testing and the association between these motivations and testing intentions in 128 college students who smoke. Exploratory factor analysis yielded four reliable factors: Test Scepticism, Test Optimism, Knowledge Enhancement and Smoking Optimism. Test Optimism and Knowledge Enhancement correlated positively with intentions to test in bivariate and multivariate analyses (ps<0.001). Test Scepticism correlated negatively with testing intentions in multivariate analyses (p<0.05). Open-ended questions assessing testing motivations generally replicated themes of the quantitative survey. In addition to learning about health risks, young people may be motivated to seek genetic testing for reasons, such as gaining knowledge about new genetic technologies more broadly.

[Depressive symptoms as a risk factor for dependence in elderly people].

PubMed

Avila-Funes, José Alberto; Melano-Carranza, Efrén; Payette, Hélène; Amieva, Hélène

2007-01-01

To determine the relationship between depressive symptoms and dependence in activities of daily living. Participants, aged 70 to 104 (n= 1 880), were evaluated twice (2001 and 2003). Depressive symptoms were established by a modified version of Center for Epidemiologic Studies Depression scale, whereas functional dependence was assessed with Lawton & Brody and Katz scales. Dependence implies the attendance and assistance of another person to accomplish the activity. Multivariate regression analyses were used to determine the effect of depressive symptoms on incident dependence. At baseline, 37.9% had depressive symptoms. After two years, 6.1 and 12.7% developed functional dependence for one or more ADL and IADL, respectively. Multivariate analyses showed that depressive symptoms were a risk factor to the development of functional dependence only for the instrumental activities for daily living. Depressive symptoms are a risk factor for functional dependence. Systematic screening it seems necessary in the evaluation of geriatric patients.

Condomless Sex Among Homeless Youth: The Role of Multidimensional Social Norms and Gender.

PubMed

Barman-Adhikari, Anamika; Hsu, Hsun-Ta; Begun, Stephanie; Portillo, Andrea Perez; Rice, Eric

2017-03-01

Most studies of condomless sex among homeless youth have focused on peer norms, while excluding other potentially pertinent influences. This study explored how different types of relationships contributed to norms about condomless sex and whether such norms were associated with engagement in condomless sex among homeless youth. Additionally, because recent work has noted gender differences in social networks of male and female homeless youth, gender differences in social network norms of condomless sex were also assessed. Egocentric network data were collected from homeless youth accessing services at two drop-in centers in Los Angeles, CA (N = 976). Multivariate analyses (non-stratified and stratified by gender) assessed associations between descriptive, injunctive, and communicative norms and participants' engagement in condomless sex. Multivariate analyses indicated that perception of peer condom use and communication with sexual partners were significantly associated with not engaging in condomless sex. These relationships, however, varied by gender. Implications for interventions are discussed.

Development of methodology for identification the nature of the polyphenolic extracts by FTIR associated with multivariate analysis.

PubMed

Grasel, Fábio dos Santos; Ferrão, Marco Flôres; Wolf, Carlos Rodolfo

2016-01-15

Tannins are polyphenolic compounds of complex structures formed by secondary metabolism in several plants. These polyphenolic compounds have different applications, such as drugs, anti-corrosion agents, flocculants, and tanning agents. This study analyses six different type of polyphenolic extracts by Fourier transform infrared spectroscopy (FTIR) combined with multivariate analysis. Through both principal component analysis (PCA) and hierarchical cluster analysis (HCA), we observed well-defined separation between condensed (quebracho and black wattle) and hydrolysable (valonea, chestnut, myrobalan, and tara) tannins. For hydrolysable tannins, it was also possible to observe the formation of two different subgroups between samples of chestnut and valonea and between samples of tara and myrobalan. Among all samples analysed, the chestnut and valonea showed the greatest similarity, indicating that these extracts contain equivalent chemical compositions and structure and, therefore, similar properties. Copyright © 2015 Elsevier B.V. All rights reserved.

A multivariate model of parent-adolescent relationship variables in early adolescence.

PubMed

McKinney, Cliff; Renk, Kimberly

2011-08-01

Given the importance of predicting outcomes for early adolescents, this study examines a multivariate model of parent-adolescent relationship variables, including parenting, family environment, and conflict. Participants, who completed measures assessing these variables, included 710 culturally diverse 11-14-year-olds who were attending a middle school in a Southeastern state. The parents of a subset of these adolescents (i.e., 487 mother-father pairs) participated in this study as well. Correlational analyses indicate that authoritative and authoritarian parenting, family cohesion and adaptability, and conflict are significant predictors of early adolescents' internalizing and externalizing problems. Structural equation modeling analyses indicate that fathers' parenting may not predict directly externalizing problems in male and female adolescents but instead may act through conflict. More direct relationships exist when examining mothers' parenting. The impact of parenting, family environment, and conflict on early adolescents' internalizing and externalizing problems and the importance of both gender and cross-informant ratings are emphasized.

Frequency and risk factors associated with emergency medical readmissions in Galway University Hospitals.

PubMed

Gorman, J; Vellinga, A; Gilmartin, J J; O'Keeffe, S T

2010-06-01

Unplanned readmissions of medical hospital patients have been increasing in recent years. We examined the frequency and associates of emergency medical readmissions to Galway University Hospitals (GUH). Readmissions during the calendar year 2006 were examined using hospital in-patient enquiry data. Associations with clinical and demographic factors were determined using univariate and multivariate analyses. The medical emergency readmission rate to GUH, after correction for death during the index admission, was 19.5%. Age 65 years or more, male gender, length of stay more than 7 days and primary diagnoses of chronic obstructive pulmonary disease, myocardial infarction, alcohol-related disease and heart failure during the index admission were significantly associated with readmission in univariate and multivariate analyses. The medical emergency readmission rate in GUH is comparable to other acute hospitals in Ireland and Britain. Further evaluation is needed to estimate the proportion of readmissions that are potentially avoidable.

Geographically Sourcing Cocaine's Origin - Delineation of the Nineteen Major Coca Growing Regions in South America.

PubMed

Mallette, Jennifer R; Casale, John F; Jordan, James; Morello, David R; Beyer, Paul M

2016-03-23

Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses ((2)H and (18)O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions.

Geographically Sourcing Cocaine’s Origin - Delineation of the Nineteen Major Coca Growing Regions in South America

NASA Astrophysics Data System (ADS)

Mallette, Jennifer R.; Casale, John F.; Jordan, James; Morello, David R.; Beyer, Paul M.

2016-03-01

Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses (2H and 18O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions.

Is bilingualism associated with a lower risk of dementia in community-living older adults? Cross-sectional and prospective analyses.

PubMed

Yeung, Caleb M; St John, Philip D; Menec, Verena; Tyas, Suzanne L

2014-01-01

The aim of this study was to determine whether bilingualism is associated with dementia in cross-sectional or prospective analyses of older adults. In 1991, 1616 community-living older adults were assessed and were followed 5 years later. Measures included age, sex, education, subjective memory loss (SML), and the modified Mini-mental State Examination (3MS). Dementia was determined by clinical examination in those who scored below the cut point on the 3MS. Language status was categorized based upon self-report into 3 groups: English as a first language (monolingual English, bilingual English) and English as a Second Language (ESL). The ESL category had lower education, lower 3MS scores, more SML, and were more likely to be diagnosed with cognitive impairment, no dementia at both time 1 and time 2 compared with those speaking English as a first language. There was no association between being bilingual (ESL and bilingual English vs. monolingual) and having dementia at time 1 in bivariate or multivariate analyses. In those who were cognitively intact at time 1, there was no association between being bilingual and having dementia at time 2 in bivariate or multivariate analyses. We did not find any association between speaking >1 language and dementia.

Metal and physico-chemical variations at a hydroelectric reservoir analyzed by Multivariate Analyses and Artificial Neural Networks: environmental management and policy/decision-making tools.

PubMed

Cavalcante, Y L; Hauser-Davis, R A; Saraiva, A C F; Brandão, I L S; Oliveira, T F; Silveira, A M

2013-01-01

This paper compared and evaluated seasonal variations in physico-chemical parameters and metals at a hydroelectric power station reservoir by applying Multivariate Analyses and Artificial Neural Networks (ANN) statistical techniques. A Factor Analysis was used to reduce the number of variables: the first factor was composed of elements Ca, K, Mg and Na, and the second by Chemical Oxygen Demand. The ANN showed 100% correct classifications in training and validation samples. Physico-chemical analyses showed that water pH values were not statistically different between the dry and rainy seasons, while temperature, conductivity, alkalinity, ammonia and DO were higher in the dry period. TSS, hardness and COD, on the other hand, were higher during the rainy season. The statistical analyses showed that Ca, K, Mg and Na are directly connected to the Chemical Oxygen Demand, which indicates a possibility of their input into the reservoir system by domestic sewage and agricultural run-offs. These statistical applications, thus, are also relevant in cases of environmental management and policy decision-making processes, to identify which factors should be further studied and/or modified to recover degraded or contaminated water bodies. Copyright © 2012 Elsevier B.V. All rights reserved.

Nitrate Intake Does Not Influence Bladder Cancer Risk: The Netherlands Cohort Study

PubMed Central

Zeegers, Maurice P.; Selen, Roel F.M.; Kleinjans, Jos C.S.; Goldbohm, R. Alexandra; van den Brandt, Piet A.

2006-01-01

Objectives N-nitroso compounds, endogenously formed from nitrate-derived nitrite, are suspected to be important bladder carcinogens. However, the association between nitrate exposure from food or drinking water and bladder cancer has not been substantially investigated in epidemiologic studies. Methods We evaluated the associations between nitrate exposure and bladder cancer in the Netherlands Cohort Study, conducted among 120,852 men and women, 55–69 years of age at entry. Information on nitrate from diet was collected via a food frequency questionnaire in 1986 and a database on nitrate content of foods. Individual nitrate exposures from beverages prepared with tap water were calculated by linking the postal code of individual residence at baseline to water company data. After 9.3 years of follow-up and after excluding subjects with incomplete or inconsistent dietary data, 889 cases and 4,441 subcohort members were available for multivariate analyses. We calculated incidence rate ratios (RR) and corresponding 95% confidence intervals (CIs) using Cox regression analyses. We also evaluated possible effect modification of dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever). Results The multivariate RRs for nitrate exposure from food, drinking water, and estimated total nitrate exposure were 1.06 (95% CI, 0.81–1.31), 1.06 (95% CI, 0.82–1.37), and 1.09 (95% CI, 0.84–1.42), respectively, comparing the highest to the lowest quintiles of intake. Dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever) had no significant impact on these results. Conclusion Although the association between nitrate exposure and bladder cancer risk is biologically plausible, our results in this study do not support an association between nitrate exposure and bladder cancer risk. PMID:17035137

The influence of marital status on the stage at diagnosis, treatment, and survival of adult patients with gastric cancer: a population-based study

PubMed Central

Yan, Shican; Liu, Xiyu; Guo, Weijian

2017-01-01

Background & Aims Marital status was reported as a prognostic factor in many cancers. However, its role in gastric cancer (GC) hasn't been thoroughly explored. In this study, we aimed to investigate the effect of marital status on survival, stage, treatment, and survival in subgroups. Methods We used the Surveillance, Epidemiology and End Results (SEER) database and identified 16910 GC patients. These patients were categorized into married (58.44%) and unmarred (41.56%) groups. Pearson chi-square, Wilcoxon-Mann-Whitney, Log-rank, multivariate Cox regression, univariate and multivariate binomial or multinomial logistic regression analysis were used in our analysis. Subgroup analyses of married versus unmarried patients were summarized in a forest plot. Results Married patients had better 5-year overall survival (OS) (32.09% VS 24.61%, P<0.001) and 5-year cancer-caused special survival (CSS) (37.74% VS 32.79%, P<0.001) than unmarried ones. Then we studied several underlying mechanisms. Firstly, married patients weren't in earlier stage at diagnosis (P=0.159). Secondly, married patients were more likely to receive surgery (P < 0.001) or radiotherapy (P < 0.001) compared with the unmarried. Thirdly, in subgroup analyses, married patients still had survival advantage in subgroups with stage II-IV and no radiotherapy. Conclusions These results showed that marital status was an independently prognostic factor for both OS and CSS in GC patients. Undertreatment and lack of social support in unmarried patients were potential explanations. With the knowledge of heterogeneous effects of marriage in subgroups, we can target unmarried patients with better social support, especially who are diagnosed at late stage and undergo no treatment. PMID:26894860

Handwriting Examination: Moving from Art to Science

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

Jarman, K.H.; Hanlen, R.C.; Manzolillo, P.A.

In this document, we present a method for validating the premises and methodology of forensic handwriting examination. This method is intuitively appealing because it relies on quantitative measurements currently used qualitatively by FDE's in making comparisons, and it is scientifically rigorous because it exploits the power of multivariate statistical analysis. This approach uses measures of both central tendency and variation to construct a profile for a given individual. (Central tendency and variation are important for characterizing an individual's writing and both are currently used by FDE's in comparative analyses). Once constructed, different profiles are then compared for individuality using clustermore » analysis; they are grouped so that profiles within a group cannot be differentiated from one another based on the measured characteristics, whereas profiles between groups can. The cluster analysis procedure used here exploits the power of multivariate hypothesis testing. The result is not only a profile grouping but also an indication of statistical significance of the groups generated.« less

Colorectal cancer screening and adverse childhood experiences: Which adversities matter?

PubMed

Alcalá, Héctor E; Keim-Malpass, Jessica; Mitchell, Emma

2017-07-01

Adverse Childhood Experiences (ACEs) have been associated with an increased risk of a variety of diseases, including cancer. However, research has not paid enough attention to the association between ACEs and cancer screening. As such, the present study examined the association between ACEs and ever using colorectal cancer (CRC) screening, among adults age 50 and over. Analyses used the 2011 Behavioral Risk Factor Surveillance System (n=24,938) to model odds of ever engaging in CRC screening from nine different adversities. Bivariate and multivariate models were fit. In bivariate models, physical abuse, having parents that were divorced or separated, and living in a household where adults treated each other violently were associated with lower odds of engaging in CRC. In multivariate models that accounted for potential confounders, emotional and sexual abuse were each associated with higher odds of engaging in CRC. Results suggest potential pathways by which early childhood experiences can impact future health behaviors. Future research should examine this association longitudinally. Copyright © 2017 Elsevier Ltd. All rights reserved.

Health-state utilities in a prisoner population: a cross-sectional survey

PubMed Central

Chong, Christopher AKY; Li, Sicong; Nguyen, Geoffrey C; Sutton, Andrew; Levy, Michael H; Butler, Tony; Krahn, Murray D; Thein, Hla-Hla

2009-01-01

Background Health-state utilities for prisoners have not been described. Methods We used data from a 1996 cross-sectional survey of Australian prisoners (n = 734). Respondent-level SF-36 data was transformed into utility scores by both the SF-6D and Nichol's method. Socio-demographic and clinical predictors of SF-6D utility were assessed in univariate analyses and a multivariate general linear model. Results The overall mean SF-6D utility was 0.725 (SD 0.119). When subdivided by various medical conditions, prisoner SF-6D utilities ranged from 0.620 for angina to 0.764 for those with none/mild depressive symptoms. Utilities derived by the Nichol's method were higher than SF-6D scores, often by more than 0.1. In multivariate analysis, significant independent predictors of worse utility included female gender, increasing age, increasing number of comorbidities and more severe depressive symptoms. Conclusion The utilities presented may prove useful for future economic and decision models evaluating prison-based health programs. PMID:19715571

Timing of opioid administration as a quality indicator for pain crises in sickle cell disease.

PubMed

Mathias, Melissa D; McCavit, Timothy L

2015-03-01

Time to opioid administration (TTO) has been suggested as a quality of care measure for sickle cell disease patients with vaso-occlusive crisis (VOC). We sought to determine whether TTO was associated with outcomes of emergency department (ED) visits for VOC. We conducted a single-center retrospective cohort study of ED visits for VOC. The primary outcome was hospital admission, with secondary outcomes of change between the first 2 pain scores, area under the curve (AUC) for pain scores at 4 hours (pain score AUC), total ED length of stay, and total intravenous opioids. In both univariate and multivariate analyses, mixed regression (logistic for admission, linear for secondary outcome variables) was used to evaluate association of TTO with outcome. In 177 subjects, 414 ED visits for VOC were identified. Inpatient admission occurred in 53% of visits. The median TTO for admitted patients was 86 minutes vs 87 minutes for those not admitted. TTO was not associated with inpatient admission in either univariate or multivariate analyses. In multivariate analyses with secondary outcomes, decreased TTO was associated with greater improvement between the first 2 pain scores, decreased pain score AUC, decreased total ED length of stay, and increased total opioids. Although TTO was not associated with admission, it was independently associated with 4 important secondary outcomes: change in initial pain scores, pain score AUC, total ED length of stay, and total intravenous opioids. The association of a process measure, TTO, with these outcomes encourages the institution of TTO reduction efforts in the ED. Copyright © 2015 by the American Academy of Pediatrics.

Prognostic importance of DNA ploidy in non-endometrioid, high-risk endometrial carcinomas.

PubMed

Sorbe, Bengt

2016-03-01

The present study investigated the predictive and prognostic impact of DNA ploidy together with other well-known prognostic factors in a series of non-endometrioid, high-risk endometrial carcinomas. From a complete consecutive series of 4,543 endometrial carcinomas of International Federation of Gynecology and Obstetrics (FIGO) stages I-IV, 94 serous carcinomas, 48 clear cell carcinomas and 231 carcinosarcomas were selected as a non-endometrioid, high-risk group for further studies regarding prognosis. The impact of DNA ploidy, as assessed by flow cytometry, was of particular focus. The age of the patients, FIGO stage, depth of myometrial infiltration and tumor expression of p53 were also included in the analyses (univariate and multivariate). In the complete series of cases, the recurrence rate was 37%, and the 5-year overall survival rate was 39% with no difference between the three histological subtypes. The primary cure rate (78%) was also similar for all tumor types studied. DNA ploidy was a significant predictive factor (on univariate analysis) for primary tumor cure rate, and a prognostic factor for survival rate (on univariate and multivariate analyses). The predictive and prognostic impact of DNA ploidy was higher in carcinosarcomas than in serous and clear cell carcinomas. In the majority of multivariate analyses, FIGO stage and depth of myometrial infiltration were the most important predictive (tumor recurrence) and prognostic (survival rate) factors. DNA ploidy status is a less important predictive and prognostic factor in non-endometrioid, high-risk endometrial carcinomas than in the common endometrioid carcinomas, in which FIGO and nuclear grade also are highly significant and important factors.

The Influence of Judgment Calls on Meta-Analytic Findings.

PubMed

Tarrahi, Farid; Eisend, Martin

2016-01-01

Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions.

Multifactorial analysis of renal transplants reported to the United Network for Organ Sharing Registry: a 1994 update.

PubMed

Gjertson, D W

1994-01-01

1. From a multivariate log-linear analysis of 57,303 renal transplants between 1988 and 1994, the top 10 factors influencing one-year and 3-year cadaveric graft survival rates were ranked as follows: [table: see text] 2. Center effects accounted for 30% and 28% of all assignable variations in one-year and 3-year outcomes, respectively. Although center variation dominated 32 other variables, most factors were relatively independent of transplant center. 3. Novel to our own multifactorial analyses of the UNOS Kidney Transplant Registry were 6 pretransplant factors (recipient pretransplant dialysis, pregnancy, PRA technique, donor disposition and preservation, and ABO compatibility). Survival rates over the various combinations of these new factors were not significantly different. 4. For the first time in our multivariate analyses, 4 posttransplantation factors (delayed graft function, rejection episodes prior to discharge, induction and maintenance drug therapies) were included in the log-linear model. It is noteworthy that graft survival in both transplant periods was seriously imperiled following delayed graft function or rejection prior to discharge, yet the accounting for these pseudo-outcome variables did not alter the influence of the remaining 31 transplant factors. Finally, maintenance drug therapies strongly influenced short-term outcomes but did not influence long-term results, except for a noteworthy trend toward increased survival rates for FK506 therapy.

Nurses' attitudes and knowledge regarding organ and tissue donation and transplantation in a provincial hospital: A descriptive and multivariate analysis.

PubMed

Lomero, Maria Del Mar; Jiménez-Herrera, María F; Rasero, Maria José; Sandiumenge, Alberto

2017-09-01

The attitudes and knowledge of nursing personnel regarding organ and tissue donation can influence the decision to donate. This study aimed to determine these two factors among nurses at a district hospital in Barcelona, Spain. A survey was carried out using a 35 item questionnaire. Results were subjected to descriptive and comparative statistical analyses using bivariate and multivariate analyses to examine the relation between demographic data and attitudes toward donation. The completion rate was 68.2%, with 98.6% of those responding stating that they were in favor of organ donation. The respondents were unsure as to whether the criteria for inclusion in transplant waiting lists were appropriate (57.5%), whereas 72.2% agreed that brain death is equivalent to death. The bivariate analysis revealed a significant association between a positive attitude toward donation and working on permanent night shift no religious beliefs. Attitudes toward donation among nurses were generally positive; a negative attitude, although attitudes towards donation among the nurses participating in the study were generally positive, it should be pointed out that when a negative attitude does exist this affects significant aspects such as belief in the diagnosis of brain death or the criteria for inclusion on the waiting list, amongst others, which reflects that specific training in donation focused on nurses continues to be needed. © 2017 John Wiley & Sons Australia, Ltd.

The Structure of Medical Informatics Journal Literature

PubMed Central

Morris, Theodore A.; McCain, Katherine W.

1998-01-01

Abstract Objective: Medical informatics is an emergent interdisciplinary field described as drawing upon and contributing to both the health sciences and information sciences. The authors elucidate the disciplinary nature and internal structure of the field. Design: To better understand the field's disciplinary nature, the authors examine the intercitation relationships of its journal literature. To determine its internal structure, they examined its journal cocitation patterns. Measurements: The authors used data from the Science Citation Index (SCI) and Social Science Citation Index (SSCI) to perform intercitation studies among productive journal titles, and software routines from SPSS to perform multivariate data analyses on cocitation data for proposed core journals. Results: Intercitation network analysis suggests that a core literature exists, one mark of a separate discipline. Multivariate analyses of cocitation data suggest that major focus areas within the field include biomedical engineering, biomedical computing, decision support, and education. The interpretable dimensions of multidimensional scaling maps differed for the SCI and SSCI data sets. Strong links to information science literature were not found. Conclusion: The authors saw indications of a core literature and of several major research fronts. The field appears to be viewed differently by authors writing in journals indexed by SCI from those writing in journals indexed by SSCI, with more emphasis placed on computers and engineering versus decision making by the former and more emphasis on theory versus application (clinical practice) by the latter. PMID:9760393

Baselining PMU Data to Find Patterns and Anomalies

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

Amidan, Brett G.; Follum, James D.; Freeman, Kimberly A.

This paper looks at the application of situational awareness methodologies with respect to power grid data. These methodologies establish baselines that look for typical patterns and atypical behavior in the data. The objectives of the baselining analyses are to provide: real-time analytics, the capability to look at historical trends and events, and reliable predictions of the near future state of the grid. Multivariate algorithms were created to establish normal baseline behavior and then score each moment in time according to its variance from the baseline. Detailed multivariate analytical techniques are described in this paper that produced ways to identify typicalmore » patterns and atypical behavior. In this case, atypical behavior is behavior that is unenvisioned. Visualizations were also produced to help explain the behavior that was identified mathematically. Examples are shown to help describe how to read and interpret the analyses and visualizations. Preliminary work has been performed on PMU data sets from BPA (Bonneville Power Administration) and EI (Eastern Interconnect). Actual results are not fully shown here because of confidentiality issues. Comparisons between atypical events found mathematically and actual events showed that many of the actual events are also atypical events; however there are many atypical events that do not correlate to any actual events. Additional work needs to be done to help classify the atypical events into actual events, so that the importance of the events can be better understood.« less

Acute suicidal ideation in middle-aged adults from Brazil. Results from the baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

PubMed

Brunoni, André R; Nunes, Maria A; Lotufo, Paulo A; Benseñor, Isabela M

2015-02-28

Suicidal ideation represents an important burden worldwide. However, little is known about it in low-/middle-income countries. We investigated this issue in a large cross-sectional of Brazilian civil servants (ELSA-Brasil, the Brazilian Health Longitudinal Study, n=15,105). Logistic univariate and multivariate analyses were performed to evaluate the strength of association (odds ratio, OR) between clinical and sociodemographic variables with acute life-weariness (tiredness of life) and suicidal thoughts. The presence of major depressive disorder (MDD), common mental disorders (CMDs), stressful life-events (SLEs) and poor self-perceived physical health was also collected. MDD and CMDs were strongly associated with suicidal ideation in univariate and multivariate analyses. For life-weariness thoughts, a modest, consistent association was found for female gender, being single, non-White ethnicity and poor education. SLEs and poor self-perceived physical health were also associated with suicidal ideation. Espiritism-Kardecism, but not other religions or Atheism/Agnosticism, was associated with lower rates of life-weariness and suicidal thoughts. To conclude, suicidal ideation does not differ in Brazil compared to developed countries, being primarily associated with psychiatric disorders and, to a lesser but significant extent, to social disadvantage, SLEs, poor self-perceived health and being single. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression

PubMed Central

Vroomen, P; de Krom, M C T F M; Wilmink, J; Kester, A; Knottnerus, J

2002-01-01

Objective: To evaluate patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression causing sciatica. Methods: The study involved 274 patients with pain radiating into the leg. All had a standardised clinical assessment and magnetic resonance (MR) imaging. The associations between patient characteristics, clinical findings, and lumbosacral nerve root compression on MR imaging were analysed. Results: Nerve root compression was associated with three patient characteristics, three symptoms, and four physical examination findings (paresis, absence of tendon reflexes, a positive straight leg raising test, and increased finger-floor distance). Multivariate analysis, analysing the independent diagnostic value of the tests, showed that nerve root compression was predicted by two patient characteristics, four symptoms, and two signs (increased finger-floor distance and paresis). The straight leg raise test was not predictive. The area under the curve of the receiver-operating characteristic was 0.80 for the history items. It increased to 0.83 when the physical examination items were added. Conclusions: Various clinical findings were found to be associated with nerve root compression on MR imaging. While this set of findings agrees well with those commonly used in daily practice, the tests tended to have lower sensitivity and specificity than previously reported. Stepwise multivariate analysis showed that most of the diagnostic information revealed by physical examination findings had already been revealed by the history items. PMID:11971050

Children and Adolescents Unvaccinated Against Measles: Geographic Clustering, Parents' Beliefs, and Missed Opportunities

PubMed Central

Marcuse, Edgar K.; Seward, Jane F.; Zhao, Zhen; Orenstein, Walter A.

2015-01-01

Objective We evaluated the extent to which children and adolescents were not vaccinated against measles (“unvaccinated”), clustering within U.S. counties, and factors associated with unvaccination, including parents' vaccine-related beliefs and missed opportunities. Methods We analyzed data from the 2010–2013 National Immunization Survey (NIS) and NIS-Teen Survey of households with 19- to 35-month-old children and 13- to 17-year-old adolescents, respectively. We used provider-reported vaccination histories to assess measles vaccination status. Results In 2013, 7.5% of children and 4.5% of adolescents were unvaccinated against measles. Four-fifths (80.0%) of unvaccinated children lived in counties containing 41.9% of the nation's children, and 80.0% of unvaccinated adolescents lived in counties containing 30.4% of the nation's adolescents. Multivariable statistical analyses found that 74.6% of children who were unvaccinated against measles missed being vaccinated for reasons other than parents' negative vaccine-related beliefs, and 89.6% could be deemed as having at least one missed opportunity for being vaccinated against measles because they were administered at least one dose of other recommended vaccines after 12 months of age. Among adolescents, multivariable analyses found that only demographic factors, not vaccine-related parental beliefs, were independently associated with being unvaccinated. Conclusions Reasons other than negative vaccine-related beliefs, including missed opportunities, accounted for the vast majority of unvaccinated children and adolescents. PMID:26327727

Treatment outcome and prognostic factors for adult patients with medulloblastoma: The Rare Cancer Network (RCN) experience.

PubMed

Atalar, Banu; Ozsahin, Mahmut; Call, Jason; Napieralska, Aleksandra; Kamer, Serra; Villa, Salvador; Erpolat, Petek; Negretti, Laura; Lassen-Ramshad, Yasmin; Onal, Cem; Akyurek, Serap; Ugurluer, Gamze; Baumert, Brigitta G; Servagi-Vernat, Stephanie; Miller, Robert C; Ozyar, Enis; Sio, Terence T

2018-04-01

The optimal treatment for adults with newly diagnosed medulloblastoma (MB) has not been defined. We report a large series of cases from the Rare Cancer Network. Thirteen institutions enrolled 206 MB patients who underwent postoperative radiotherapy (RT) between 1976 and 2014. Log-rank univariate and Cox-modeled multivariate analyses were used to analyze data collected. Median patient age was 29 years; follow-up was 31 months. All patients had the tumor resected; surgery was complete in 140 (68%) patients. Postoperative RT was given in 202 (98%) patients, and 94% received craniospinal irradiation (CSI) and, usually, a posterior fossa boost. Ninety-eight (48%) patients had chemotherapy, mostly cisplatin and vincristine-based. The 10-year local control, overall survival, and disease-free survival rates were 46%, 51%, and 38%, respectively. In multivariate analyses, Karnofsky Performance Status (KPS) ≥80 and CSI were significant for disease-free and overall survival (P ≤ .04 for all); receiving chemotherapy and KPS ≥80 correlated with better local-control rates. Patients with high KPS who received CSI had better rates of disease-free and overall survival. Chemotherapy was associated with better local control. These results may serve as a benchmark for future studies designed to improve outcomes for adults with medulloblastoma. Copyright © 2018 Elsevier B.V. All rights reserved.

Factors Associated with Pain Severity in Children with Calcaneal Apophysitis (Sever Disease).

PubMed

James, Alicia M; Williams, Cylie M; Luscombe, Michelle; Hunter, Reshele; Haines, Terry P

2015-08-01

To identify any association between the pain experienced as a result of calcaneal apophysitis, anthropometric data, and lower limb measurements. This study was a cross-sectional study, nested within a wider randomized, comparative efficacy trial. One hundred twenty-four children between the ages of 8 and 14 years with a clinical diagnosis of calcaneal apophysitis were recruited for this study. Of the participating children, 72 were male. The measures recorded were height, weight, waist circumference, body mass index, foot posture, and ankle joint range of motion; comparison with normative values was also completed. Univariate and multivariable regression analyses were undertaken to identify factors associated with the severity of pain experienced (visual analog scale). The children within this study had a higher mean body mass index (P < .001), increased weight (P < .001), and were taller (P < .001) compared with normative values. The children also demonstrated differences in foot posture and ankle joint range of motion. Multivariable regression analyses identified that older participants (P = .046) and those who had experienced pain for longer (P = .043) reported higher pain severity. Children presenting with calcaneal apophysitis were anthropometrically different from their peers and had experienced a lengthy period of pain. Therefore, early management focussing on the anthropometric differences may minimize the intensity and duration of pain experienced. Registered with Australian New Zealand Clinical Trials Registry: ACTRN12609000696291. Copyright © 2015 Elsevier Inc. All rights reserved.

Is treatment under general anaesthesia associated with dental neglect and dental disability among caries active preschool children?

PubMed

Kvist, T; Zedrén-Sunemo, J; Graca, E; Dahllöf, G

2014-10-01

To study if treatment under general anaesthesia (GA) is associated with dental neglect or dental disability. This was a retrospective study. Dental records of all children in the age 0-6 years who underwent GA at a specialist paediatric dentistry clinic during 2006-2011 were studied with regard to decayed-missed-filled teeth, traumatic injuries, emergency visits, behaviour management problems and the history of attendance. The final sample consisted of 134 children. Matched controls were selected among recall patients who had not received treatment under GA. Fishers exact test or Pearson Chi-square test analysed response distribution and comparisons between groups, and for multivariate analyses, logistic regression was used. The results show that children treated under GA had significantly higher caries prevalence, apical periodontitis and infections due to pulpal necrosis. Dental neglect as well as dental disability was significantly more prevalent in the GA group compared to the control group. In a multivariate analysis with dental neglect as independent factor, dental disability was the only significant factor (p = 0.006). Children treated under general anaesthesia were significantly more often diagnosed with both dental neglect and dental disability. Dental disability was the only factor significantly related to dental neglect. There is a need for improved documentation in the dental records to better identify dental neglect and dental disability, and also a continued training of dentists regarding child protection.

Patient satisfaction with intravenous acetaminophen: a pooled analysis of five randomized, placebo-controlled studies in the acute postoperative setting.

PubMed

Apfel, Christian C; Souza, Kimberly; Portillo, Juan; Dalal, Poorvi; Bergese, Sergio D

2015-01-01

Intravenous (IV) acetaminophen has been shown to reduce postoperative pain and opioid consumption, which may lead to increased patient satisfaction. To determine the effect IV acetaminophen has on patient satisfaction, a pooled analysis from methodologically homogenous studies was conducted. We obtained patient-level data from five randomized, placebo-controlled studies in adults undergoing elective surgery in which patient satisfaction was measured using a 4-point categorical rating scale. The primary endpoint was "excellent" satisfaction and the secondary endpoint was "good" or "excellent" satisfaction at 24 hr after first study drug administration. Bivariate analyses were conducted using the chi-square test and Student's t-test and multivariable analyses were conducted using logistic regression analysis. Patients receiving IV acetaminophen were more than twice as likely as those who received placebo to report "excellent" patient satisfaction ratings (32.3% vs. 15.9%, respectively). Of all variables that remained statistically significant in the multivariable analysis (i.e., type of surgery, duration of anesthesia, last pain rating, and opioid consumption), IV acetaminophen had the strongest positive effect on "excellent" patient satisfaction with an odds ratio of 2.76 (95% CI 1.81-4.23). Results for "excellent" or "good" satisfaction were similar. When given as part of a perioperative analgesic regimen, IV acetaminophen was associated with significantly improved patient satisfaction.

[Quality assurance program for pain management after obstetrical perineal injury].

PubMed

Urion, L; Bayoumeu, F; Jandard, C; Fontaine, B; Bouaziz, H

2004-11-01

A quality insurance program has been set up in order to improve the relief of pain in patients with perineal injury after childbirth. The program has been developed according to the French standards of accreditation. After elaboration of a referential, a first study (103 patients) allowed to evaluate the ongoing practices and to appreciate the pain intensities. After analysis of the results, an action strategy has been elaborated, with a brand new therapeutic standard and a pain-monitoring program for nurses. Six months later, a second study (105 patients) measured the efficiency of the accomplished actions. The statistic analysis used chi2 and Kruskal-Wallis tests and a multivariate analyse (p <0.05). Several indicators led to conclude to the success of this program: analgesics prescribed systematically and earlier, best observance, larger utilisation of the NSAI, decrease of the analgesics requests, improvement of the satisfaction referred to the relief of pain. The multivariate analyse showed a risk twice as little as in the second study to have a 36th hour VAS score superior to four (p =0.03). The apply of this quality insurance program allowed to improve the analgesia after obstetric perineal injuries. A few adaptations are needed, and also more formations of the medical and paramedical staff. The durability of the accomplished actions shall be evaluated in the future.

Univariate and multivariate molecular spectral analyses of lipid related molecular structural components in relation to nutrient profile in feed and food mixtures

NASA Astrophysics Data System (ADS)

Abeysekara, Saman; Damiran, Daalkhaijav; Yu, Peiqiang

2013-02-01

The objectives of this study were (i) to determine lipid related molecular structures components (functional groups) in feed combination of cereal grain (barley, Hordeum vulgare) and wheat (Triticum aestivum) based dried distillers grain solubles (wheat DDGSs) from bioethanol processing at five different combination ratios using univariate and multivariate molecular spectral analyses with infrared Fourier transform molecular spectroscopy, and (ii) to correlate lipid-related molecular-functional structure spectral profile to nutrient profiles. The spectral intensity of (i) CH3 asymmetric, CH2 asymmetric, CH3 symmetric and CH2 symmetric groups, (ii) unsaturation (Cdbnd C) group, and (iii) carbonyl ester (Cdbnd O) group were determined. Spectral differences of functional groups were detected by hierarchical cluster analysis (HCA) and principal components analysis (PCA). The results showed that the combination treatments significantly inflicted modifications (P < 0.05) in nutrient profile and lipid related molecular spectral intensity (CH2 asymmetric stretching peak height, CH2 symmetric stretching peak height, ratio of CH2 to CH3 symmetric stretching peak intensity, and carbonyl peak area). Ratio of CH2 to CH3 symmetric stretching peak intensity, and carbonyl peak significantly correlated with nutrient profiles. Both PCA and HCA differentiated lipid-related spectrum. In conclusion, the changes of lipid molecular structure spectral profiles through feed combination could be detected using molecular spectroscopy. These changes were associated with nutrient profiles and functionality.

Factors Associated with Sexual Risk of HIV Transmission Among HIV-Positive Latino Men Who have Sex with Men on the U.S.-México Border

PubMed Central

Kutner, Bryan A.; Nelson, Kimberly M.; Simoni, Jane M.; Sauceda, John A.; Wiebe, John S.

2016-01-01

We present results from a cross-sectional, clinic-based survey of border-region Latino men who have sex with men (MSM) and who also are living with HIV in the El Paso-Ciudad Juárez area. Among the 66 participants who reported serodiscordant anal or vaginal intercourse, we examined levels of psychological distress and substance use and the association of these variables with condomless sex. Bivariate analyses indicated that MSM who reported condomless sex with a serodiscordant partner were more likely to report higher scores on measures of anxiety, depression, and trauma. These men were also more likely to report more days of alcohol use to the point of intoxication. In multivariate logistic regression, no variables were independently associated with sexual risk behavior, but symptoms of anxiety trended toward statistical significance. Our study is one of few reports aimed at understanding the HIV epidemic among Latino MSM living with HIV in the El Paso-Ciudad Juárez border region. Although we found no evidence of a relation between our measures of psychological distress and substance use and sexual risk behavior in multivariate analyses, psychological distress and problematic alcohol use were common in the sample and are important targets for intervention in their own right. PMID:27278549

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.

Measuring Professional Identity Development among Counselor Trainees

ERIC Educational Resources Information Center

Prosek, Elizabeth A.; Hurt, Kara M.

2014-01-01

This study examined the differences in professional identity development between novice and advanced counselor trainees (N = 161). Multivariate analyses of variance indicated significant differences between groups. Specifically, advanced counselor trainees demonstrated greater professional development compared with novice counselor trainees. No…

Statistical analyses of the results of 25 years of beach litter surveys on the south-eastern North Sea coast.

PubMed

Schulz, Marcus; Clemens, Thomas; Förster, Harald; Harder, Thorsten; Fleet, David; Gaus, Silvia; Grave, Christel; Flegel, Imme; Schrey, Eckart; Hartwig, Eike

2015-08-01

In the North Sea, the amount of litter present in the marine environment represents a severe environmental problem. In order to assess the magnitude of the problem and measure changes in abundance, the results of two beach litter monitoring programmes were compared and analysed for long-term trends applying multivariate techniques. Total beach litter pollution was persistently high. Spatial differences in litter abundance made it difficult to identify long-term trends: Partly more than 8000 litter items year(-1) were recorded on a 100 m long survey site on the island of Scharhörn, while the survey site on the beach on the island of Amrum revealed abundances lower by two orders of magnitude. Beach litter was dominated by plastic with mean proportions of 52%-91% of total beach litter. Non-parametric time series analyses detected many significant trends, which, however, did not show any systematic spatial patterns. Cluster analyses partly led to groupings of beaches according to their expositions to sources of litter, wind and currents. Surveys in short intervals of one to two weeks were found to give higher annual sums of beach litter than the quarterly surveys of the OSPAR method. Surveys at regular intervals of four weeks to five months would make monitoring results more reliable. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Does placental inflammation relate to brain lesions and volume in preterm infants?

PubMed

Reiman, Milla; Kujari, Harry; Maunu, Jonna; Parkkola, Riitta; Rikalainen, Hellevi; Lapinleimu, Helena; Lehtonen, Liisa; Haataja, Leena

2008-05-01

To evaluate the association between histologic inflammation of placenta and brain findings in ultrasound examinations and regional brain volumes in magnetic resonance imaging in very-low-birth-weight (VLBW) or in very preterm infants. VLBW or very preterm infants (n = 121) were categorized into 3 groups according to the most pathologic brain finding on ultrasound examinations until term. The brain magnetic resonance imaging performed at term was analyzed for regional brain volumes. The placentas were analyzed for histologic inflammatory findings. Histologic chorioamnionitis on the fetal side correlated to brain lesions in univariate but not in multivariate analyses. Low gestational age was the only significant risk factor for brain lesions in multivariate analysis (P < .0001). Histologic chorioamnionitis was not associated with brain volumes in multivariate analyses. Female sex, low gestational age, and low birth weight z score correlated to smaller volumes in total brain tissue (P = .001, P = .0002, P < .0001, respectively) and cerebellum (P = .047, P = .003, P = .001, respectively). In addition, low gestational age and low-birth-weight z score correlated to a smaller combined volume of basal ganglia and thalami (P = .0002). Placental inflammation does not appear to correlate to brain lesions or smaller regional brain volumes in VLBW or in very preterm infants at term age.

Changes in chemical composition of bone matrix in ovariectomized (OVX) rats detected by Raman spectroscopy and multivariate analysis

NASA Astrophysics Data System (ADS)

Oshima, Yusuke; Iimura, Tadahiro; Saitou, Takashi; Imamura, Takeshi

2015-02-01

Osteoporosis is a major bone disease that connotes the risk of fragility fractures resulting from alterations to bone quantity and/or quality to mechanical competence. Bone strength arises from both bone quantity and quality. Assessment of bone quality and bone quantity is important for prediction of fracture risk. In spite of the two factors contribute to maintain the bone strength, only one factor, bone mineral density is used to determine the bone strength in the current diagnosis of osteoporosis. On the other hand, there is no practical method to measure chemical composition of bone tissue including hydroxyapatite and collagen non-invasively. Raman spectroscopy is a powerful technique to analyze chemical composition and material properties of bone matrix non-invasively. Here we demonstrated Raman spectroscopic analysis of the bone matrix in osteoporosis model rat. Ovariectomized (OVX) rat was made and the decalcified sections of tibias were analyzed by a Raman microscope. In the results, Raman bands of typical collagen appeared in the obtained spectra. Although the typical mineral bands at 960 cm-1 (Phosphate) was absent due to decalcified processing, we found that Raman peak intensities of amide I and C-C stretching bands were significantly different between OVX and sham-operated specimens. These differences on the Raman spectra were statistically compared by multivariate analyses, principal component analysis (PCA) and liner discrimination analysis (LDA). Our analyses suggest that amide I and C-C stretching bands can be related to stability of bone matrix which reflects bone quality.

Antenatal Risk Factors of Postpartum Depression at 20 Weeks Gestation in a Japanese Sample: Psychosocial Perspectives from a Cohort Study in Tokyo

PubMed Central

Tachibana, Yoshiyuki; Koizumi, Tomoe; Takehara, Kenji; Kakee, Naoko; Tsujii, Hiromi; Mori, Rintaro; Inoue, Eisuke; Ota, Erika; Yoshida, Keiko; Kasai, Keiko; Okuyama, Makiko; Kubo, Takahiko

2015-01-01

Background Prevalence of postnatal depression (PND) is high (Western countries, 10–15%; Japan, 17%). PND can cause parenting impairment and affect family health (e.g. child behaviors, cognitive development and physical health). This study aimed to reveal the risk factors of PND during the pregnancy period in a Japanese sample, and to identify the psychosocial risk factors of PND that should be appended to existing obstetric interview sheets. A cohort study with a Japanese sample was conducted. Methods All 14 obstetrics hospitals in the Setagaya ward, Tokyo, Japan, participated in this study. Pregnant women who booked their delivery between December 2012 and May 2013 were enrolled. Data used for this study were collected at 20 weeks gestation, a few days and one month postnatal. The questionnaires consisted of psychosocial factors and the Edinburgh Postnatal Depression Scale (EPDS). To identify PND risk factors, multivariate analyses were performed. Results A total of 1,775 women participated in this study. Eventually, the data of 1,133 women were used for the multivariate analyses. The demonstrated significant risk factors include EPDS score, primipara, “a perceived lack of family cohesion”, “current physical illness treatment” and “current psychiatric illness treatment”. Conclusion This study highlights the importance of mental health screening using psychological measures during the pregnancy period. In addition, family environment, parity, physical and psychiatric illness should be paid attention by professionals in maternal and child health. The results also suggest that mothers’ feelings of developing their families should be supported. PMID:26625132

Clinicopathological factors increased the risk of malignancy in thyroid nodules with atypical or follicular lesions of undetermined significance (AUS/FLUS) risk factor of malignancy in thyroid nodule with AUS/FLUS

PubMed Central

Hong, In Ki; Kim, Jun Ho; Cho, Young Up; Park, Shin-Young

2016-01-01

Purpose Ultrasound-guided fine needle aspiration (US-FNA) in thyroid nodules is presently most commonly used to identify whether these nodules are benign or malignant. However, atypical or follicular lesions of undetermined significance (AUS/FLUS), as categorized in the Bethesda System for reporting the results of FNA, cannot be classified as benign or malignant. Therefore, several clinical factors should be considered to assess the risk of malignancy in patients with AUS/FLUS. The purpose of the present study was to determine which clinical factor increased the risk of malignancy in patients with AUS/FLUS. Methods A retrospective study was done on 129 patients with fine needle aspiration categorized as AUS/FLUS from January 2011 through April 2015. Univariate and multivariate analyses were performed to assess the independent effect of risk factors such as age, sex, size of nodule, atypical descriptors, and ultrasonography criteria for malignancy. Results We identified that the presence of spiculated margin (odds ratio [OR], 5.655; 95% confidence interval [CI], 2.114-15.131; P = 0.001), nuclear grooving (OR, 3.697; 95% CI, 1.409-9.701; P = 0.008), irregular nuclei (OR, 3.903; 95% CI, 1.442-10.560; P = 0.001) were shown to be significantly related to malignancy on univariate and multivariate analyses. Conclusion We recommend that surgical resection of thyroid nodules be considered in patients with AUS/FLUS showing the histologic findings such as nuclear grooving, irregular nuclei along with spiculated margin of ultrasonographic finding. PMID:27073790

Prevalence of and Factors Associated with Negative Microscopic Diagnosis of Cutaneous Leishmaniasis in Rural Peru.

PubMed

Lamm, Ryan; Alves, Clark; Perrotta, Grace; Murphy, Meagan; Messina, Catherine; Sanchez, Juan F; Perez, Erika; Rosales, Luis Angel; Lescano, Andres G; Smith, Edward; Valdivia, Hugo; Fuhrer, Jack; Ballard, Sarah-Blythe

2018-06-04

Cutaneous leishmaniasis is endemic to South America where diagnosis is most commonly conducted via microscopy. Patients with suspected leishmaniasis were referred for enrollment by the Ministry of Health (MoH) in Lima, Iquitos, Puerto Maldonado, and several rural areas of Peru. A 43-question survey requesting age, gender, occupation, characterization of the lesion(s), history of leishmaniasis, and insect-deterrent behaviors was administered. Polymerase chain reaction (PCR) was conducted on lesion materials at the Naval Medical Research Unit No. 6 in Lima, and the results were compared with those obtained by the MoH using microscopy. Factors associated with negative microscopy and positive PCR results were identified using χ 2 test, t -test, and multivariate logistic regression analyses. Negative microscopy with positive PCR occurred in 31% (123/403) of the 403 cases. After adjusting for confounders, binary multivariate logistic regression analyses revealed that negative microscopy with positive PCR was associated with patients who were male (adjusted OR = 1.93 [1.06-3.53], P = 0.032), had previous leishmaniasis (adjusted OR = 2.93 [1.65-5.22], P < 0.0001), had larger lesions (adjusted OR = 1.02 [1.003-1.03], P = 0.016), and/or had a longer duration between lesion appearance and PCR testing (adjusted OR = 1.12 [1.02-1.22], P = 0.017). Future research should focus on further exploration of these underlying variables, discovery of other factors that may be associated with negative microscopy diagnosis, and the development and implementation of improved testing in endemic regions.

Improving the quality of pressure ulcer care with prevention: a cost-effectiveness analysis.

PubMed

Padula, William V; Mishra, Manish K; Makic, Mary Beth F; Sullivan, Patrick W

2011-04-01

In October 2008, Centers for Medicare and Medicaid Services discontinued reimbursement for hospital-acquired pressure ulcers (HAPUs), thus placing stress on hospitals to prevent incidence of this costly condition. To evaluate whether prevention methods are cost-effective compared with standard care in the management of HAPUs. A semi-Markov model simulated the admission of patients to an acute care hospital from the time of admission through 1 year using the societal perspective. The model simulated health states that could potentially lead to an HAPU through either the practice of "prevention" or "standard care." Univariate sensitivity analyses, threshold analyses, and Bayesian multivariate probabilistic sensitivity analysis using 10,000 Monte Carlo simulations were conducted. Cost per quality-adjusted life-years (QALYs) gained for the prevention of HAPUs. Prevention was cost saving and resulted in greater expected effectiveness compared with the standard care approach per hospitalization. The expected cost of prevention was $7276.35, and the expected effectiveness was 11.241 QALYs. The expected cost for standard care was $10,053.95, and the expected effectiveness was 9.342 QALYs. The multivariate probabilistic sensitivity analysis showed that prevention resulted in cost savings in 99.99% of the simulations. The threshold cost of prevention was $821.53 per day per person, whereas the cost of prevention was estimated to be $54.66 per day per person. This study suggests that it is more cost effective to pay for prevention of HAPUs compared with standard care. Continuous preventive care of HAPUs in acutely ill patients could potentially reduce incidence and prevalence, as well as lead to lower expenditures.

Effect of Cobicistat on Tenofovir Disoproxil Fumarate (TDF): What Is True for TAF May Also Be True for TDF.

PubMed

Cattaneo, Dario; Minisci, Davide; Baldelli, Sara; Mazzali, Cristina; Giacomelli, Andrea; Milazzo, Laura; Meraviglia, Paola; Resnati, Chiara; Rizzardini, Giuliano; Clementi, Emilio; Galli, Massimo; Gervasoni, Cristina

2018-01-01

The dose of tenofovir alafenamide is reduced from 25 to 10 mg daily when given with boosting agents. However, such dose reduction has never been adopted for tenofovir disoproxil fumarate (TDF). In this study, we aim to quantify the effect of cobicistat (COBI) both on tenofovir concentrations and TDF durability in real life setting. HIV-positive patients receiving TDF-containing antiretroviral therapies with at least 1 assessment of tenofovir plasma trough concentrations were included in the study. Univariate and multivariate regression analyses were performed considering tenofovir concentration as the dependent variable and clinical characteristics as independent covariates. Subsequently, survival and Cox analyses were performed considering as the primary outcome TDF discontinuation for any reasons. Patients were given TDF with protease inhibitors/ritonavir (n = 212), non-nucleoside reverse transcriptase inhibitors (n = 176), integrase inhibitors (dolutegravir or raltegravir, n = 46), or with elvitegravir/COBI (ELV/COBI) (n = 76). By multivariate analysis, concomitant antiretroviral therapies resulted significantly associated with tenofovir levels, with the highest drug concentrations measured in patients given ELV/COBI. By survival analysis, we found that patients given TDF with ELV/COBI had the lowest rate of drug durability. Overall, these patients had a 2.3-fold increased risk to experience TDF discontinuation. Coadministration with COBI resulted in significantly higher tenofovir concentrations and higher TDF discontinuation compared with other antiretroviral regimens. Accordingly, the possibility that the lack of proper dose adjustment for TDF when given with COBI might have biased the safety comparisons with tenofovir alafenamide during registrative trials cannot be ruled out.

Stigma and Parenting Children Conceived From Sexual Violence

PubMed Central

Rouhani, Shada A.; Scott, Jennifer; Greiner, Ashley; Albutt, Katherine; Hacker, Michele R.; Kuwert, Philipp; VanRooyen, Michael; Bartels, Susan

2016-01-01

BACKGROUND AND OBJECTIVES Since armed conflict began in 1996, widespread sexual violence in eastern Democratic Republic of Congo has resulted in many sexual violence-related pregnancies (SVRPs). However, there are limited data on the relationships between mothers and their children from sexual violence. This study aimed to evaluate the nature and determinants of these maternal–child relationships. METHODS Using respondent-driven sampling, 757 women raising children from SVRPs in South Kivu Province, Democratic Republic of Congo were interviewed. A parenting index was created from questions assessing the maternal–child relationship. The influences of social stigma, family and community acceptance, and maternal mental health on the parenting index were assessed in univariate and multivariable analyses. RESULTS The majority of mothers reported positive attitudes toward their children from SVRPs. Prevalence of perceived family or community stigma toward the women or their children ranged from 31.8% to 42.9%, and prevalence of perceived family or community acceptance ranged from 45.2% to 73.5%. In multivariable analyses, stigma toward the child, as well as maternal anxiety and depression, were associated with lower parenting indexes, whereas acceptance of the mother or child and presence of a spouse were associated with higher parenting indexes (all P ≤ .01). CONCLUSIONS In this study with a large sample size, stigma and mental health disorders negatively influenced parenting attitudes, whereas family and community acceptance were associated with adaptive parenting attitudes. Interventions to reduce stigmatization, augment acceptance, and improve maternal mental health may improve the long-term well-being of mothers and children from SVRPs. PMID:26438704

Implementation of a guideline for local health policy making by regional health services: exploring determinants of use by a web survey.

PubMed

Kuunders, Theo J M; Jacobs, Monique A M; Goor, Ien A M van de; Bon-Martens, Marja J H van; Oers, Hans A M van; Paulussen, Theo G W M

2017-08-15

Previous evaluation showed insufficient use of a national guideline for integrated local health policy by Regional Health Services (RHS) in the Netherlands. The guideline focuses on five health topics and includes five checklists to support integrated municipal health policies. This study explores the determinants of guideline use by regional Dutch health professionals. A web survey was send to 304 RHS health professionals. The questionnaire was based on a theory- and research-based framework of determinants of public health innovations. Main outcomes were guideline use and completeness of use, defined as the number of health topics and checklists used. Associations between determinants and (completeness of) guideline use were explored by multivariate regression models. The survey was started by 120 professionals (39%). Finally, results from 73 respondents (24%) were eligible for analyses. All 28 Dutch RHS organizations were represented in the final dataset. About half of the respondents (48%) used the guideline. The average score for completeness of use (potential range 1-10) was 2.37 (sd = 1.78; range 1-7). Knowledge, perceived task responsibility and usability were significantly related to guideline use in univariate analyses. Only usability remained significant in the multivariate model on guideline use. Only self-efficacy accounted for significant proportions of variance in completeness of use. The results imply that strategies to improve guideline use by RHSs should primarily target perceived usability. Self-efficacy appeared the primary target for improving completeness of guideline use. Methods for targeting these determinants in RHSs are discussed.

Risk of Peripheral Artery Occlusive Disease in Patients with Vertigo, Tinnitus, or Sudden Deafness: A Secondary Case-Control Analysis of a Nationwide, Population-Based Health Claims Database

PubMed Central

Hwang, Juen-Haur

2016-01-01

Background Cochleovestibular symptoms, such as vertigo, tinnitus, and sudden deafness, are common manifestations of microvascular diseases. However, it is unclear whether these symptoms occurred preceding the diagnosis of peripheral artery occlusive disease (PAOD). Therefore, the aim of this case-control study was to investigate the risk of PAOD among patients with vertigo, tinnitus, and sudden deafness using a nationwide, population-based health claim database in Taiwan. Methods We identified 5,340 adult patients with PAOD diagnosed between January 1, 2006 and December 31, 2010 and 16,020 controls, frequency matched on age interval, sex, and year of index date, from the Taiwan National Health Insurance Research Database. Risks of PAOD in patients with vertigo, tinnitus, or sudden deafness were separately evaluated with multivariate logistic regression analyses. Results Of the 5,340 patients with PAOD, 12.7%, 6.7%, and 0.3% were diagnosed with vertigo, tinnitus, and sudden deafness, respectively. In the controls, 10.6%, 6.1%, and 0.3% were diagnosed with vertigo (P < 0.001), tinnitus (P = 0.161), and sudden deafness (P = 0.774), respectively. Results from the multivariate logistic regression analyses showed that the risk of PAOD was significantly increased in patients with vertigo (adjusted odds ratio = 1.12, P = 0.027) but not in those with tinnitus or sudden deafness. Conclusions A modest increase in the risk of PAOD was observed among Taiwanese patients with vertigo, after adjustment for comorbidities. PMID:27631630

In Quest of the Alanine R3 Radical: Multivariate EPR Spectral Analyses of X-Irradiated Alanine in the Solid State.

PubMed

Jåstad, Eirik O; Torheim, Turid; Villeneuve, Kathleen M; Kvaal, Knut; Hole, Eli O; Sagstuen, Einar; Malinen, Eirik; Futsaether, Cecilia M

2017-09-28

The amino acid l-α-alanine is the most commonly used material for solid-state electron paramagnetic resonance (EPR) dosimetry, due to the formation of highly stable radicals upon irradiation, with yields proportional to the radiation dose. Two major alanine radical components designated R1 and R2 have previously been uniquely characterized from EPR and electron-nuclear double resonance (ENDOR) studies as well as from quantum chemical calculations. There is also convincing experimental evidence of a third minor radical component R3, and a tentative radical structure has been suggested, even though no well-defined spectral signature has been observed experimentally. In the present study, temperature dependent EPR spectra of X-ray irradiated polycrystalline alanine were analyzed using five multivariate methods in further attempts to understand the composite nature of the alanine dosimeter EPR spectrum. Principal component analysis (PCA), maximum likelihood common factor analysis (MLCFA), independent component analysis (ICA), self-modeling mixture analysis (SMA), and multivariate curve resolution (MCR) were used to extract pure radical spectra and their fractional contributions from the experimental EPR spectra. All methods yielded spectral estimates resembling the established R1 spectrum. Furthermore, SMA and MCR consistently predicted both the established R2 spectrum and the shape of the R3 spectrum. The predicted shape of the R3 spectrum corresponded well with the proposed tentative spectrum derived from spectrum simulations. Thus, results from two independent multivariate data analysis techniques strongly support the previous evidence that three radicals are indeed present in irradiated alanine samples.

Compound effects of temperature and precipitation in making droughts more frequent in Marathwada, India

NASA Astrophysics Data System (ADS)

Mondal, A.; Zachariah, M.; Achutarao, K. M.; Otto, F. E. L.

2017-12-01

The Marathwada region in Maharashtra, India is known to suffer significantly from agrarian crisis including farmer suicides resulting from persistent droughts. Drought monitoring in India is commonly based on univariate indicators that consider the deficiency in precipitation alone. However, droughts may involve complex interplay of multiple physical variables, necessitating an integrated, multivariate approach to analyse their behaviour. In this study, we compare the behaviour of drought characteristics in Marathwada in the recent years as compared to the first half of the twentieth century, using a joint precipitation and temperature-based Multivariate Standardized Drought Index (MSDI). Drought events in the recent times are found to exhibit exceptional simultaneous anomalies of high temperature and precipitation deficits in this region, though studies on precipitation alone show that these events are within the range of historically observed variability. Additionally, we also develop multivariate copula-based Severity-Duration-Frequency (SDF) relationships for droughts in this region and compare their natures pre- and post- 1950. Based on multivariate return periods considering both temperature and precipitation anomalies, as well as the severity and duration of droughts, it is found that droughts have become more frequent in the post-1950 period. Based on precipitation alone, such an observation cannot be made. This emphasizes the sensitivity of droughts to temperature and underlines the importance of considering compound effects of temperature and precipitation in order to avoid an underestimation of drought risk. This observation-based analysis is the first step towards investigating the causal mechanisms of droughts, their evolutions and impacts in this region, particularly those influenced by anthropogenic climate change.

Does resting-state connectivity reflect depressive rumination? A tale of two analyses.

PubMed

Berman, Marc G; Misic, Bratislav; Buschkuehl, Martin; Kross, Ethan; Deldin, Patricia J; Peltier, Scott; Churchill, Nathan W; Jaeggi, Susanne M; Vakorin, Vasily; McIntosh, Anthony R; Jonides, John

2014-12-01

Major Depressive Disorder (MDD) is characterized by rumination. Prior research suggests that resting-state brain activation reflects rumination when depressed individuals are not task engaged. However, no study has directly tested this. Here we investigated whether resting-state epochs differ from induced ruminative states for healthy and depressed individuals. Most previous research on resting-state networks comes from seed-based analyses with the posterior cingulate cortex (PCC). By contrast, we examined resting state connectivity by using the complete multivariate connectivity profile (i.e., connections across all brain nodes) and by comparing these results to seeded analyses. We find that unconstrained resting-state intervals differ from active rumination states in strength of connectivity and that overall connectivity was higher for healthy vs. depressed individuals. Relationships between connectivity and subjective mood (i.e., behavior) were strongly observed during induced rumination epochs. Furthermore, connectivity patterns that related to subjective mood were strikingly different for MDD and healthy control (HC) groups suggesting different mood regulation mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

Epidemiologic programs for computers and calculators. A microcomputer program for multiple logistic regression by unconditional and conditional maximum likelihood methods.

PubMed

Campos-Filho, N; Franco, E L

1989-02-01

A frequent procedure in matched case-control studies is to report results from the multivariate unmatched analyses if they do not differ substantially from the ones obtained after conditioning on the matching variables. Although conceptually simple, this rule requires that an extensive series of logistic regression models be evaluated by both the conditional and unconditional maximum likelihood methods. Most computer programs for logistic regression employ only one maximum likelihood method, which requires that the analyses be performed in separate steps. This paper describes a Pascal microcomputer (IBM PC) program that performs multiple logistic regression by both maximum likelihood estimation methods, which obviates the need for switching between programs to obtain relative risk estimates from both matched and unmatched analyses. The program calculates most standard statistics and allows factoring of categorical or continuous variables by two distinct methods of contrast. A built-in, descriptive statistics option allows the user to inspect the distribution of cases and controls across categories of any given variable.

Statistical Analyses of Raw Material Data for MTM45-1/CF7442A-36% RW: CMH Cure Cycle

NASA Technical Reports Server (NTRS)

Coroneos, Rula; Pai, Shantaram, S.; Murthy, Pappu

2013-01-01

This report describes statistical characterization of physical properties of the composite material system MTM45-1/CF7442A, which has been tested and is currently being considered for use on spacecraft structures. This composite system is made of 6K plain weave graphite fibers in a highly toughened resin system. This report summarizes the distribution types and statistical details of the tests and the conditions for the experimental data generated. These distributions will be used in multivariate regression analyses to help determine material and design allowables for similar material systems and to establish a procedure for other material systems. Additionally, these distributions will be used in future probabilistic analyses of spacecraft structures. The specific properties that are characterized are the ultimate strength, modulus, and Poisson??s ratio by using a commercially available statistical package. Results are displayed using graphical and semigraphical methods and are included in the accompanying appendixes.

Detection and identification of extra virgin olive oil adulteration by GC-MS combined with chemometrics.

PubMed

Yang, Yang; Ferro, Miguel Duarte; Cavaco, Isabel; Liang, Yizeng

2013-04-17

In this study, an analytical method for the detection and identification of extra virgin olive oil adulteration with four types of oils (corn, peanut, rapeseed, and sunflower oils) was proposed. The variables under evaluation included 22 fatty acids and 6 other significant parameters (the ratio of linoleic/linolenic acid, oleic/linoleic acid, total saturated fatty acids (SFAs), polyunsaturated fatty acids (PUFAs), monounsaturated fatty acids (MUFAs), MUFAs/PUFAs). Univariate analyses followed by multivariate analyses were applied to the adulteration investigation. As a result, the univariate analyses demonstrated that higher contents of eicosanoic acid, docosanoic acid, tetracosanoic acid, and SFAs were the peculiarities of peanut adulteration and higher levels of linolenic acid, 11-eicosenoic acid, erucic acid, and nervonic acid the characteristics of rapeseed adulteration. Then, PLS-LDA made the detection of adulteration effective with a 1% detection limit and 90% prediction ability; a Monte Carlo tree identified the type of adulteration with 85% prediction ability.

Does decisional conflict differ across race and ethnicity groups? A study of parents whose children have a life-threatening illness.

PubMed

Knapp, Caprice; Sberna-Hinojosa, Melanie; Baron-Lee, Jacqueline; Curtis, Charlotte; Huang, I-Chan

2014-05-01

Children with life-threatening illnesses and their families may face a myriad of medical decisions in their lifetimes. Oftentimes these complicated medical decisions cause disagreements among patients, families, and providers about what is the best course of action. Although no evidence exists, it is possible that conflict may affect subgroups of the population differently. This study aims to investigate how decisional conflict varies among racial and ethnic subgroups. Two hundred sixty-six surveys were completed with parents whose children have a life-threatening illness. All children lived in Florida and were enrolled in the Medicaid program. The Decisional Conflict Scale, overall and broken down into its five distinct subscales, was used to assess parental decision-making. Descriptive, bivariate, and multivariate analyses were conducted. Subgroup analyses were conducted on Latino respondents. Our bivariate results suggest that minority parents report less Effective Decision Making (p<0.05) and report less Support in Decision Making (p<0.05) compared to white, non-Hispanic parents. For the subgroup analysis, we found that those who identify as Mexican American and Central/South American report having greater Uncertainty in Choosing Options (p<0.05) and less Values Clarity (p<0.05) as compared to Puerto Rican or Cuban Americans. Results from the multivariate analyses suggest that those whose primary language is not English are associated with greater Uncertainty in Choosing Options (p<0.05). Values Clarity was lower for children who were diagnosed with their life-threatening condition at birth (p<0.05) as compared to children diagnosed at a later time. Our study is the first to describe racial and ethnic differences in decisional conflict of parents of children with life-threatening illnesses. Significant differences exist by race, ethnicity, language spoken, and diagnosis time across several subdomains of decisional conflict. These differences are important to address when creating clinical care plans, engaging in shared decision-making, and creating interventions to alleviate decisional conflict.

Multivariate Statistical Analysis of MSL APXS Bulk Geochemical Data

NASA Astrophysics Data System (ADS)

Hamilton, V. E.; Edwards, C. S.; Thompson, L. M.; Schmidt, M. E.

2014-12-01

We apply cluster and factor analyses to bulk chemical data of 130 soil and rock samples measured by the Alpha Particle X-ray Spectrometer (APXS) on the Mars Science Laboratory (MSL) rover Curiosity through sol 650. Multivariate approaches such as principal components analysis (PCA), cluster analysis, and factor analysis compliment more traditional approaches (e.g., Harker diagrams), with the advantage of simultaneously examining the relationships between multiple variables for large numbers of samples. Principal components analysis has been applied with success to APXS, Pancam, and Mössbauer data from the Mars Exploration Rovers. Factor analysis and cluster analysis have been applied with success to thermal infrared (TIR) spectral data of Mars. Cluster analyses group the input data by similarity, where there are a number of different methods for defining similarity (hierarchical, density, distribution, etc.). For example, without any assumptions about the chemical contributions of surface dust, preliminary hierarchical and K-means cluster analyses clearly distinguish the physically adjacent rock targets Windjana and Stephen as being distinctly different than lithologies observed prior to Curiosity's arrival at The Kimberley. In addition, they are separated from each other, consistent with chemical trends observed in variation diagrams but without requiring assumptions about chemical relationships. We will discuss the variation in cluster analysis results as a function of clustering method and pre-processing (e.g., log transformation, correction for dust cover) and implications for interpreting chemical data. Factor analysis shares some similarities with PCA, and examines the variability among observed components of a dataset so as to reveal variations attributable to unobserved components. Factor analysis has been used to extract the TIR spectra of components that are typically observed in mixtures and only rarely in isolation; there is the potential for similar results with data from APXS. These techniques offer new ways to understand the chemical relationships between the materials interrogated by Curiosity, and potentially their relation to materials observed by APXS instruments on other landed missions.

Geometric morphometric analysis of mandibular shape diversity in Pan.

PubMed

Robinson, Chris

2012-07-01

The aim of this research is to determine whether geometric morphometric (GM) techniques can provide insights into how the shape of the mandibular corpus differs between bonobos and chimpanzees and to explore the potential implications of those results for our understanding of hominin evolution. We focused on this region of the mandible because of the relative frequency with which it has been recovered in the hominin fossil record. In addition, no previous study had explored in-depth three-dimensional (3D) mandibular corpus shape differences between adults of the two Pan species using geometric morphometrics. GM methods enable researchers to quantitatively analyze and visualize 3D shape changes in skeletal elements and provide an important compliment to traditional two-dimensional analyses. Eighteen mandibular landmarks were collected using a Microscribe 3DX portable digitizer. Specimen configurations were superimposed using Generalized Procrustes analysis and the projections of the fitted coordinates to tangent space were analyzed using multivariate statistics. The size-adjusted corpus shapes of Pan paniscus and Pan troglodytes could be assigned to species with approximately 93% accuracy and the Procrustes distance between the two species was significant. Analyses of the residuals from a multivariate linear regression of the data on centroid size suggested that much of the shape difference between the species is size-related. Chimpanzee subspecies and a small sample of Australopithecus specimens could be correctly identified to taxon, at best, only 75% of the time, although the Procrustes distances between these taxa were significant. The shape of the mandibular symphysis was identified as especially useful in differentiating Pan species from one another. This suggests that this region of the mandible has the potential to be informative for taxonomic analyses of fossil hominoids, including hominins. The results also have implications for phylogenetic hypotheses of hominoid evolution. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Impact of Risk Factors of Chronic Pancreatitis on Secretin Pancreatic Function Testing: Results of a 20-Year Study.

PubMed

Kothari, Darshan; Ketwaroo, Gyanprakash; Freedman, Steven D; Sheth, Sunil G

2017-08-01

The aim of this study was to determine the effect of established risk factors on the outcome of secretin pancreatic function testing (sPFT) in patients undergoing work-up for suspected chronic pancreatitis. We completed a retrospective review of patients who underwent sPFT for suspected chronic pancreatitis over 20 years. We compared peak bicarbonate concentrations between groups and completed univariate and multivariate analyses to determine associations between risk factors and positive sPFT results (peak bicarbonate <80 mEq/L). Forty-three of 162 patients had positive sPFT results. There were significant differences in peak bicarbonate concentrations in patients with and without recurrent acute pancreatitis (RAP) and with local complications from acute pancreatitis (AP) (P ≤ 0.05). The bicarbonate concentration in patients with and without other risk factors such as tobacco use, alcohol use, and family history of pancreatitis was not significantly different. Female sex, a history of AP, and a history of RAP were associated with positive sPFT results on univariate analysis (P ≤ 0.05). On multivariate analysis, sex and RAP remained significant. Our study demonstrates that female sex, history of AP and RAP, and AP with local complications are associated with positive sPFT results or lower peak bicarbonate concentration. However, other risk factors do not impact the results of sPFT.

Improved neutron-gamma discrimination for a 3He neutron detector using subspace learning methods

DOE PAGES

Wang, C. L.; Funk, L. L.; Riedel, R. A.; ...

2017-02-10

3He gas based neutron linear-position-sensitive detectors (LPSDs) have been applied for many neutron scattering instruments. Traditional Pulse-Height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio on the orders of 10 5-10 6. The NGD ratios of 3He detectors need to be improved for even better scientific results from neutron scattering. Digital Signal Processing (DSP) analyses of waveforms were proposed for obtaining better NGD ratios, based on features extracted from rise-time, pulse amplitude, charge integration, a simplified Wiener filter, and the cross-correlation between individual and template waveforms of neutron and gamma events. Fisher linear discriminant analysis (FLDA)more » and three multivariate analyses (MVAs) of the features were performed. The NGD ratios are improved by about 10 2-10 3 times compared with the traditional PHA method. Finally, our results indicate the NGD capabilities of 3He tube detectors can be significantly improved with subspace-learning based methods, which may result in a reduced data-collection time and better data quality for further data reduction.« less

Social-ecological factors and preventive actions decrease the risk of dengue infection at the household-level: Results from a prospective dengue surveillance study in Machala, Ecuador

PubMed Central

Kenneson, Aileen; Beltrán-Ayala, Efraín; Borbor-Cordova, Mercy J.; Polhemus, Mark E.; Ryan, Sadie J.; Endy, Timothy P.

2017-01-01

Background In Ecuador, dengue virus (DENV) infections transmitted by the Aedes aegypti mosquito are among the greatest public health concerns in urban coastal communities. Community- and household-level vector control is the principal means of controlling disease outbreaks. This study aimed to assess the impact of knowledge, attitudes, and practices (KAPs) and social-ecological factors on the presence or absence of DENV infections in the household. Methods In 2014 and 2015, individuals with DENV infections from sentinel clinics in Machala, Ecuador, were invited to participate in the study, as well as members of their household and members of four neighboring households located within 200 meters. We conducted diagnostic testing for DENV on all study participants; we surveyed heads of households (HOHs) regarding demographics, housing conditions and KAPs. We compared KAPs and social-ecological factors between households with (n = 139) versus without (n = 80) DENV infections, using bivariate analyses and multivariate logistic regression models with and without interactions. Results Significant risk factors in multivariate models included proximity to abandoned properties, interruptions in piped water, and shaded patios (p<0.05). Significant protective factors included the use of mosquito bed nets, fumigation inside the home, and piped water inside the home (p<0.05). In bivariate analyses (but not multivariate modeling), DENV infections were positively associated with HOHs who were male, employed, and of younger age than households without infections (p<0.05). DENV infections were not associated with knowledge, attitude, or reported barriers to prevention activities. Discussion Specific actions that can be considered to decrease the risk of DENV infections in the household include targeting vector control in highly shaded properties, fumigating inside the home, and use of mosquito bed nets. Community-level interventions include cleanup of abandoned properties, daily garbage collection, and reliable piped water inside houses. These findings can inform interventions to reduce the risk of other diseases transmitted by the Ae. aegypti mosquito, such as chikungunya and Zika fever. PMID:29253873

Introduction to uses and interpretation of principal component analyses in forest biology.

Treesearch

J. G. Isebrands; Thomas R. Crow

1975-01-01

The application of principal component analysis for interpretation of multivariate data sets is reviewed with emphasis on (1) reduction of the number of variables, (2) ordination of variables, and (3) applications in conjunction with multiple regression.

Is the pattern of intellectual growth and decline across the adult life span different for men and women?

PubMed

Kaufman, A S; Kaufman-Packer, J L; McLean, J E; Reynolds, C R

1991-11-01

Gender comparisons on the WAIS-R were made for 1,480 adults from the standardization sample, ages 20-74 years, to determine whether men and women differ in their age-related patterns of change on tests of fluid and crystallized abilities. Multivariate analyses of covariance and univariate analyses of covariance were conducted, covarying education, to examine the age + gender interactions. These interactions tended to be nonsignificant and trivial for the WAIS-R Verbal and Performance scales and the 11 subtests, which suggests that both men and women maintain their crystallized abilities through old age, but show early, rapid declines in fluid ability. These results were interpreted in terms of the literature on aging and intelligence, gender differences in cognitive abilities, and gender differences in V-P patterns for patients with unilateral brain damage.

National Income Inequality and Declining GDP Growth Rates Are Associated with Increases in HIV Diagnoses among People Who Inject Drugs in Europe: A Panel Data Analysis

PubMed Central

Nikolopoulos, Georgios K.; Fotiou, Anastasios; Kanavou, Eleftheria; Richardson, Clive; Detsis, Marios; Pharris, Anastasia; Suk, Jonathan E.; Semenza, Jan C.; Costa-Storti, Claudia; Paraskevis, Dimitrios; Sypsa, Vana; Malliori, Melpomeni-Minerva; Friedman, Samuel R.; Hatzakis, Angelos

2015-01-01

Background There is sparse evidence that demonstrates the association between macro-environmental processes and drug-related HIV epidemics. The present study explores the relationship between economic, socio-economic, policy and structural indicators, and increases in reported HIV infections among people who inject drugs (PWID) in the European Economic Area (EEA). Methods We used panel data (2003–2012) for 30 EEA countries. Statistical analyses included logistic regression models. The dependent variable was taking value 1 if there was an outbreak (significant increase in the national rate of HIV diagnoses in PWID) and 0 otherwise. Explanatory variables included the growth rate of Gross Domestic Product (GDP), the share of the population that is at risk for poverty, the unemployment rate, the Eurostat S80/S20 ratio, the Gini coefficient, the per capita government expenditure on health and social protection, and variables on drug control policy and drug-using population sizes. Lags of one to three years were investigated. Findings In multivariable analyses, using two-year lagged values, we found that a 1% increase of GDP was associated with approximately 30% reduction in the odds of an HIV outbreak. In GDP-adjusted analyses with three-year lagged values, the effect of the national income inequality on the likelihood of an HIV outbreak was significant [S80/S20 Odds Ratio (OR) = 3.89; 95% Confidence Interval (CI): 1.15 to 13.13]. Generally, the multivariable analyses produced similar results across three time lags tested. Interpretation Given the limitations of ecological research, we found that declining economic growth and increasing national income inequality were associated with an elevated probability of a large increase in the number of HIV diagnoses among PWID in EEA countries during the last decade. HIV prevention may be more effective if developed within national and European-level policy contexts that promote income equality, especially among vulnerable groups. PMID:25875598

Splenectomy Causes 10-Fold Increased Risk of Portal Venous System Thrombosis in Liver Cirrhosis Patients.

PubMed

Qi, Xingshun; Han, Guohong; Ye, Chun; Zhang, Yongguo; Dai, Junna; Peng, Ying; Deng, Han; Li, Jing; Hou, Feifei; Ning, Zheng; Zhao, Jiancheng; Zhang, Xintong; Wang, Ran; Guo, Xiaozhong

2016-07-19

BACKGROUND Portal venous system thrombosis (PVST) is a life-threatening complication of liver cirrhosis. We conducted a retrospective study to comprehensively analyze the prevalence and risk factors of PVST in liver cirrhosis. MATERIAL AND METHODS All cirrhotic patients without malignancy admitted between June 2012 and December 2013 were eligible if they underwent contrast-enhanced CT or MRI scans. Independent predictors of PVST in liver cirrhosis were calculated in multivariate analyses. Subgroup analyses were performed according to the severity of PVST (any PVST, main portal vein [MPV] thrombosis >50%, and clinically significant PVST) and splenectomy. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. RESULTS Overall, 113 cirrhotic patients were enrolled. The prevalence of PVST was 16.8% (19/113). Splenectomy (any PVST: OR=11.494, 95%CI=2.152-61.395; MPV thrombosis >50%: OR=29.987, 95%CI=3.247-276.949; clinically significant PVST: OR=40.415, 95%CI=3.895-419.295) and higher hemoglobin (any PVST: OR=0.974, 95%CI=0.953-0.996; MPV thrombosis >50%: OR=0.936, 95%CI=0.895-0.980; clinically significant PVST: OR=0.935, 95%CI=0.891-0.982) were the independent predictors of PVST. The prevalence of PVST was 13.3% (14/105) after excluding splenectomy. Higher hemoglobin was the only independent predictor of MPV thrombosis >50% (OR=0.952, 95%CI=0.909-0.997). No independent predictors of any PVST or clinically significant PVST were identified in multivariate analyses. Additionally, PVST patients who underwent splenectomy had a significantly higher proportion of clinically significant PVST but lower MELD score than those who did not undergo splenectomy. In all analyses, the in-hospital mortality was not significantly different between cirrhotic patient with and without PVST. CONCLUSIONS Splenectomy may increase by at least 10-fold the risk of PVST in liver cirrhosis independent of severity of liver dysfunction.

Splenectomy Causes 10-Fold Increased Risk of Portal Venous System Thrombosis in Liver Cirrhosis Patients

PubMed Central

Qi, Xingshun; Han, Guohong; Ye, Chun; Zhang, Yongguo; Dai, Junna; Peng, Ying; Deng, Han; Li, Jing; Hou, Feifei; Ning, Zheng; Zhao, Jiancheng; Zhang, Xintong; Wang, Ran; Guo, Xiaozhong

2016-01-01

Background Portal venous system thrombosis (PVST) is a life-threatening complication of liver cirrhosis. We conducted a retrospective study to comprehensively analyze the prevalence and risk factors of PVST in liver cirrhosis. Material/Methods All cirrhotic patients without malignancy admitted between June 2012 and December 2013 were eligible if they underwent contrast-enhanced CT or MRI scans. Independent predictors of PVST in liver cirrhosis were calculated in multivariate analyses. Subgroup analyses were performed according to the severity of PVST (any PVST, main portal vein [MPV] thrombosis >50%, and clinically significant PVST) and splenectomy. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Results Overall, 113 cirrhotic patients were enrolled. The prevalence of PVST was 16.8% (19/113). Splenectomy (any PVST: OR=11.494, 95%CI=2.152–61.395; MPV thrombosis >50%: OR=29.987, 95%CI=3.247–276.949; clinically significant PVST: OR=40.415, 95%CI=3.895–419.295) and higher hemoglobin (any PVST: OR=0.974, 95%CI=0.953–0.996; MPV thrombosis >50%: OR=0.936, 95%CI=0.895–0.980; clinically significant PVST: OR=0.935, 95%CI=0.891–0.982) were the independent predictors of PVST. The prevalence of PVST was 13.3% (14/105) after excluding splenectomy. Higher hemoglobin was the only independent predictor of MPV thrombosis >50% (OR=0.952, 95%CI=0.909–0.997). No independent predictors of any PVST or clinically significant PVST were identified in multivariate analyses. Additionally, PVST patients who underwent splenectomy had a significantly higher proportion of clinically significant PVST but lower MELD score than those who did not undergo splenectomy. In all analyses, the in-hospital mortality was not significantly different between cirrhotic patient with and without PVST. Conclusions Splenectomy may increase by at least 10-fold the risk of PVST in liver cirrhosis independent of severity of liver dysfunction. PMID:27432511

National income inequality and declining GDP growth rates are associated with increases in HIV diagnoses among people who inject drugs in Europe: a panel data analysis.

PubMed

Nikolopoulos, Georgios K; Fotiou, Anastasios; Kanavou, Eleftheria; Richardson, Clive; Detsis, Marios; Pharris, Anastasia; Suk, Jonathan E; Semenza, Jan C; Costa-Storti, Claudia; Paraskevis, Dimitrios; Sypsa, Vana; Malliori, Melpomeni-Minerva; Friedman, Samuel R; Hatzakis, Angelos

2015-01-01

There is sparse evidence that demonstrates the association between macro-environmental processes and drug-related HIV epidemics. The present study explores the relationship between economic, socio-economic, policy and structural indicators, and increases in reported HIV infections among people who inject drugs (PWID) in the European Economic Area (EEA). We used panel data (2003-2012) for 30 EEA countries. Statistical analyses included logistic regression models. The dependent variable was taking value 1 if there was an outbreak (significant increase in the national rate of HIV diagnoses in PWID) and 0 otherwise. Explanatory variables included the growth rate of Gross Domestic Product (GDP), the share of the population that is at risk for poverty, the unemployment rate, the Eurostat S80/S20 ratio, the Gini coefficient, the per capita government expenditure on health and social protection, and variables on drug control policy and drug-using population sizes. Lags of one to three years were investigated. In multivariable analyses, using two-year lagged values, we found that a 1% increase of GDP was associated with approximately 30% reduction in the odds of an HIV outbreak. In GDP-adjusted analyses with three-year lagged values, the effect of the national income inequality on the likelihood of an HIV outbreak was significant [S80/S20 Odds Ratio (OR) = 3.89; 95% Confidence Interval (CI): 1.15 to 13.13]. Generally, the multivariable analyses produced similar results across three time lags tested. Given the limitations of ecological research, we found that declining economic growth and increasing national income inequality were associated with an elevated probability of a large increase in the number of HIV diagnoses among PWID in EEA countries during the last decade. HIV prevention may be more effective if developed within national and European-level policy contexts that promote income equality, especially among vulnerable groups.

A Cyber-Attack Detection Model Based on Multivariate Analyses

NASA Astrophysics Data System (ADS)

Sakai, Yuto; Rinsaka, Koichiro; Dohi, Tadashi

In the present paper, we propose a novel cyber-attack detection model based on two multivariate-analysis methods to the audit data observed on a host machine. The statistical techniques used here are the well-known Hayashi's quantification method IV and cluster analysis method. We quantify the observed qualitative audit event sequence via the quantification method IV, and collect similar audit event sequence in the same groups based on the cluster analysis. It is shown in simulation experiments that our model can improve the cyber-attack detection accuracy in some realistic cases where both normal and attack activities are intermingled.

Fathers' Depression Related to Positive and Negative Parenting Behaviors With 1-Year-Old Children

PubMed Central

Davis, Matthew M.; Freed, Gary L.; Clark, Sarah J.

2011-01-01

OBJECTIVE: To examine the associations between depression in fathers of 1-year-old children and specific positive and negative parenting behaviors discussed by pediatric providers at well-child visits. METHODS: We performed a cross-sectional secondary analysis by using interview data from 1746 fathers of 1-year-old children in the Fragile Families and Child Wellbeing Study. Positive parenting behaviors included fathers' reports of playing games, singing songs, and reading stories to their children ≥3 days in a typical week. Negative parenting behavior included fathers' reports of spanking their 1-year-old children in the previous month. Depression was assessed by using the World Health Organization Composite International Diagnostic Interview Short Form. Weighted bivariate and multivariate analyses of parenting behaviors were performed while controlling for demographics and paternal substance abuse. RESULTS: Overall, 7% of fathers had depression. In bivariate analyses, depressed fathers were more likely than nondepressed fathers to report spanking their 1-year-old children in the previous month (41% compared with 13%; P < .01). In multivariate analyses, depressed fathers were less likely to report reading to their children ≥3 days in a typical week (adjusted odds ratio: 0.38 [95% confidence interval: 0.15–0.98]) and much more likely to report spanking (adjusted odds ratio: 3.92 [95% confidence interval: 1.23–12.5]). Seventy-seven percent of depressed fathers reported talking to their children's doctor in the previous year. CONCLUSIONS: Paternal depression is associated with parenting behaviors relevant to well-child visits. Pediatric providers should consider screening fathers for depression, discussing specific parenting behaviors (eg, reading to children and appropriate discipline), and referring for treatment if appropriate. PMID:21402627

Understanding the trends in HIV and hepatitis C prevalence amongst injecting drug users in different settings--implications for intervention impact.

PubMed

Vickerman, Peter; Martin, Natasha K; Hickman, Matthew

2012-06-01

A recent systematic review observed that HIV prevalence amongst injectors is negligible (<1%) below a threshold HCV prevalence of 30%, but thereafter increases with HCV prevalence. We explore whether a model can reproduce these trends, what determines different epidemiological profiles and how this affects intervention impact. An HIV/HCV transmission model was developed. Univariate sensitivity analyses determined whether the model projected a HCV prevalence threshold below which HIV is negligible, and how different behavioural and epidemiological factors affect the threshold. Multivariate uncertainty analyses considered whether the model could reproduce the observed breadth of HIV/HCV epidemics, how specific behavioural patterns produce different epidemic profiles, and how this affects an intervention's impact (reduces injecting risk by 30%). The model projected a HCV prevalence threshold, which varied depending on the heterogeneity in risk, mixing, and injecting duration in a setting. Multivariate uncertainty analyses showed the model could produce the same range of observed HIV/HCV epidemics. Variability in injecting transmission risk, degree of heterogeneity and injecting duration mainly determined different epidemic profiles. The intervention resulted in 50%/28% reduction in HIV incidence/prevalence and 37%/10% reduction in HCV incidence/prevalence over five years. For either infection, greater impact occurred in settings with lower prevalence of that infection and higher prevalence of the other infection. There are threshold levels of HCV prevalence below which HIV risk is negligible but these thresholds are likely to vary by setting. A setting's HIV and HCV prevalence may give insights into IDU risk behaviour and intervention impact. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Resident Participation in Fixation of Intertrochanteric Hip Fractures: Analysis of the NSQIP Database.

PubMed

Neuwirth, Alexander L; Stitzlein, Russell N; Neuwirth, Madalyn G; Kelz, Rachel K; Mehta, Samir

2018-01-17

Future generations of orthopaedic surgeons must continue to be trained in the surgical management of hip fractures. This study assesses the effect of resident participation on outcomes for the treatment of intertrochanteric hip fractures. The National Surgical Quality Improvement Program (NSQIP) database (2010 to 2013) was queried for intertrochanteric hip fractures (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 820.21) treated with either extramedullary (Current Procedural Terminology [CPT] code 27244) or intramedullary (CPT code 27245) fixation. Demographic variables, including resident participation, as well as primary (death and serious morbidity) and secondary outcome variables were extracted for analysis. Univariate, propensity score-matched, and multivariate logistic regression analyses were performed to evaluate outcome variables. Data on resident participation were available for 1,764 cases (21.0%). Univariate analyses for all intertrochanteric hip fractures demonstrated no significant difference in 30-day mortality (6.3% versus 7.8%; p = 0.264) or serious morbidity (44.9% versus 43.2%; p = 0.506) between the groups with and without resident participation. Multivariate and propensity score-matched analyses gave similar results. Resident involvement was associated with prolonged operating-room time, length of stay, and time to discharge when a prolonged case was defined as one above the 90th percentile for time parameters. Resident participation was not associated with an increase in morbidity or mortality but was associated with an increase in time-related secondary outcome measures. While attending surgeon supervision is necessary, residents can and should be involved in the care of these patients without concern that resident involvement negatively impacts perioperative morbidity and mortality. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Non-smoker assertive behaviour against smoke exposure: Chinese and Korean American non-smokers.

PubMed

Saw, Anne; Tang, Hao; Tsoh, Janice Y; Chen, Moon S; Tong, Elisa K

2017-11-01

Non-smokers' assertive behaviour towards smokers by asking them not to smoke is important in promoting smoke-free environments. Korean and Chinese Americans come from countries where most women are non-smokers and assertive behaviour may not be prevalent but may increase after migration because of social-ecological factors. This study assessed the extent to which Korean and Chinese American non-smokers ask someone not to smoke and associated factors. The 2003 California Chinese American and Korean American Tobacco Use Surveys were analysed. Multivariate logistic regression analyses examined factors related to non-smoker self-reports that they asked someone not to smoke within the past year. About 40% reported past-year assertive behaviour against smoking, with higher rates among Koreans than Chinese (60.4% vs. 34.5%), those living with smokers (63.5%), ever exposed with a smoke-free home rule (62.3%), recently exposed at work without a smoke-free work policy (67.6%) and regularly exposed at other locations (52.3%). In combined multivariate analyses of both ethnic groups, assertive behaviour was associated with individual factors (single vs. married; tobacco exposure knowledge), family factors (living with smokers, exposed at home despite a smoke-free rule), community factors (exposed at work with no smoke-free policy, exposed at other locations) and cultural factors (Korean vs. Chinese ethnicity; lower acculturation). Chinese and Korean American non-smokers report assertive behaviour against smoking, which is associated with social-ecological factors. Results help identify target groups and strategies for future intervention, including the need to implement or enforce smoke-free environments and promote empowerment. [Saw A, Tang H, Tsoh JY, Chen MS Jr, Tong EK. Non-smoker assertive behaviour against smoke exposure: Chinese and Korean American non-smokers. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Effects of proton pump inhibitors and histamine-2 receptor antagonists on response to fidaxomicin or vancomycin in patients with Clostridium difficile-associated diarrhoea

PubMed Central

Weiss, Karl; Louie, Thomas; Miller, Mark A; Mullane, Kathleen; Crook, Derrick W; Gorbach, Sherwood L

2015-01-01

Objective It has been established that use of proton pump inhibitors (PPIs) is associated with an increased risk of acquiring Clostridium difficile-associated diarrhoea (CDAD). However, it is not known whether the use of PPIs or histamine-2 receptor antagonists (H2RAs) concurrently with CDAD-targeted antibiotic treatment affects clinical response or recurrence rates. Design In two phase 3 trials, patients with toxin-positive CDAD were randomised to receive fidaxomicin 200 mg twice daily or vancomycin 125 mg four times daily for 10 days. Only inpatients with CDAD (due to complete medication record availability) were included in this post hoc analysis: 701 patients, of whom 446 (64%) used PPIs or H2RAs during study drug treatment or follow-up. Baseline factors that were statistically significant in univariate analyses were analysed in multivariate analyses of effects on clinical response and recurrence. Results Multivariate analysis showed that leukocytosis, elevated creatinine and hypoalbuminemia, but not PPI or H2RA use, were significant factors associated with poor clinical responses. Treatment group was the single significant predictor of recurrence; the probability of recurrence after fidaxomicin therapy was half that following vancomycin therapy. Conclusions Acid-suppressing drugs, used by nearly two-thirds of inpatients with CDAD, did not worsen clinical response or recurrence when used concurrently with fidaxomicin or vancomycin. Therefore, development of CDAD does not require discontinuation of anti-acid treatment in patients who have an indication for continuing PPI or H2RA therapy, such as gastro-oesophageal reflux disease and risk of gastrointestinal bleed. PMID:26462279

Identifying Children At Risk for Being Bullies in the US

PubMed Central

Shetgiri, Rashmi; Lin, Hua; Flores, Glenn

2012-01-01

Objective To identify risk factors associated with the highest and lowest prevalence of bullying perpetration among US children. Methods Using the 2001–2002 Health Behavior in School-Aged Children, a nationally-representative survey of US children in 6th–10th grades, bivariate analyses were conducted to identify factors associated with any (≥ once or twice), moderate (≥ two-three times/month), and frequent (≥ weekly) bullying. Stepwise multivariable analyses identified risk factors associated with bullying. Recursive partitioning analysis (RPA) identified risk factors which, in combination, identify students with the highest and lowest bullying prevalence. Results The prevalence of any bullying in the 13,710 students was 37.3%, moderate bullying was 12.6%, and frequent bullying was 6.6%. Characteristics associated with bullying were similar in the multivariable analyses and RPA clusters. In RPA, the highest prevalence of any bullying (67%) accrued in children with a combination of fighting and weapon-carrying. Students who carry weapons, smoke, and drink alcohol more than 5–6 days weekly were at highest risk for moderate bullying (61%). Those who carry weapons, smoke, drink > once daily, have above-average academic performance, moderate/high family affluence, and feel irritable or bad-tempered daily were at highest risk for frequent bullying (68%). Conclusions Risk clusters for any, moderate, and frequent bullying differ. Children who fight and carry weapons are at highest risk of any bullying. Weapon-carrying, smoking, and alcohol use are included in the highest risk clusters for moderate and frequent bullying. Risk-group categories may be useful to providers in identifying children at highest risks for bullying and in targeting interventions. PMID:22989731

Relationship between water quality and macro-scale parameters (land use, erosion, geology, and population density) in the Siminehrood River Basin.

PubMed

Bostanmaneshrad, Farshid; Partani, Sadegh; Noori, Roohollah; Nachtnebel, Hans-Peter; Berndtsson, Ronny; Adamowski, Jan Franklin

2018-10-15

To date, few studies have investigated the simultaneous effects of macro-scale parameters (MSPs) such as land use, population density, geology, and erosion layers on micro-scale water quality variables (MSWQVs). This research focused on an evaluation of the relationship between MSPs and MSWQVs in the Siminehrood River Basin, Iran. In addition, we investigated the importance of water particle travel time (hydrological distance) on this relationship. The MSWQVs included 13 physicochemical and biochemical parameters observed at 15 stations during three seasons. Primary screening was performed by utilizing three multivariate statistical analyses (Pearson's correlation, cluster and discriminant analyses) in seven series of observed data. These series included three separate seasonal data, three two-season data, and aggregated three-season data for investigation of relationships between MSPs and MSWQVs. Coupled data (pairs of MSWQVs and MSPs) repeated in at least two out of three statistical analyses were selected for final screening. The primary screening results demonstrated significant relationships between land use and phosphorus, total solids and turbidity, erosion levels and electrical conductivity, and erosion and total solids. Furthermore, water particle travel time effects were considered through three geographical pattern definitions of distance for each MSP by using two weighting methods. To find effective MSP factors on MSWQVs, a multivariate linear regression analysis was employed. Then, preliminary equations that estimated MSWQVs were developed. The preliminary equations were modified to adaptive equations to obtain the final models. The final models indicated that a new metric, referred to as hydrological distance, provided better MSWQV estimation and water quality prediction compared to the National Sanitation Foundation Water Quality Index. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Epidemiology of Skin Cancer in the German Population: Impact of Socioeconomic and Geographic Factors.

PubMed

Augustin, J; Kis, A; Sorbe, C; Schäfer, I; Augustin, M

2018-04-06

Skin cancer being the most common cancer in Germany has shown increasing incidence in the past decade. Since mostly caused by excessive UV exposure, skin cancer is largely related to behaviour. So far, the impact of regional and sociodemographic factors on the development of skin cancer in Germany is unclear. The current study aimed to investigate the association of potential predictive factors with the prevalence of skin cancers in Germany. Nationwide ambulatory care claims data from persons insured in statutory health insurances (SHI) with malignant melanoma (MM, ICD-10 C43) and non-melanoma skin cancer (NMSC, ICD-10 C44) in the years 2009-2015 were analysed. In addition, sociodemographic population data and satellite based UV and solar radiation data were associated. Descriptive as well as multivariate (spatial) statistical analyses (for example Bayes' Smoothing) were conducted on county level. Data from 70.1 million insured persons were analysed. Age standardized prevalences per 100,000 SHI insured persons for MM and NMSC were 284.7 and 1126.9 in 2009 and 378.5 and 1708.2 in 2015. Marked regional variations were observed with prevalences between 32.9% and 51.6%. Multivariate analysis show statistically significant positive correlations between higher income and education, and MM/NMSC prevalence. Prevalence of MM and NMSC in Germany shows spatio-temporal dynamics. Our results show that regional UV radiation, sunshine hours and sociodemographic factors have significant impact on skin cancer prevalence in Germany. Individual behaviour obviously is a major determinant which should be subject to preventive interventions. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The prevalence and characteristics of low back pain among sitting workers in a Japanese manufacturing company.

PubMed

Inoue, Gen; Miyagi, Masayuki; Uchida, Kentaro; Ishikawa, Tetsuhiro; Kamoda, Hiroto; Eguchi, Yawara; Orita, Sumihisa; Yamauchi, Kazuyo; Takaso, Masashi; Tsuchiya, Kei-Ichi; Takahashi, Kazuhisa; Ohtori, Seiji

2015-01-01

Low back pain (LBP) is a major public health problem and the most common cause of workers' disability, resulting in substantial economic burden in terms of workers' compensation and medical costs. Sitting is a recognized potential risk factor for developing LBP. Therefore, eliminating risk factors associated with working conditions and individual work capacity may be beneficial in preventing LBP in sitting workers. The purpose of this prospective cross-sectional study is to investigate the prevalence of LBP and examine risk factors that contribute to the development of LBP in sitting workers at an electronics manufacturing company. A cross-sectional survey was administered to all subjects to assess the prevalence of LBP persisting for at least 48 h during the recent week. Data on demographic characteristics and potential risk factors for LBP were collected at routine annual check-ups. Patients with LBP completed the Roland-Morris Disability Questionnaire (RDQ), which provided information on the attributes of LBP. Univariate and multivariate regression analyses examined the association between LBP and potential risk factors. Of the 1,329 sitting workers, 201 (15.1 %) acknowledged experiencing LBP during the recent week. In female workers, weight and body mass index were significantly correlated with the RDQ score. Univariate analyses identified male sex, prior history of LBP, height ≥170 cm, and weight ≥70 kg as significant risk factors of LBP. Multivariate logistic regression analyses identified prior history of LBP and past history of lumbar spine surgery as significant risk factors of LBP. This study characterized the prevalence and attributes of LBP in Japanese sitting workers and provided information about potential risk factors contributing to occurrence of LBP in the workplace.

Patient-reported safety incidents in older patients with long-term conditions: a large cross-sectional study

PubMed Central

Panagioti, Maria; Blakeman, Thomas; Hann, Mark; Bower, Peter

2017-01-01

Background Increasing evidence suggests that patient safety is a serious concern for older patients with long-term conditions. Despite this, there is a lack of research on safety incidents encountered by this patient group. In this study, we sought to examine patient reports of safety incidents and factors associated with reports of safety incidents in older patients with long-term conditions. Methods The baseline cross-sectional data from a longitudinal cohort study were analysed. Older patients (n=3378 aged 65 years and over) with a long-term condition registered in general practices were included in the study. The main outcome was patient-reported safety incidents including availability and appropriateness of medical tests and prescription of wrong types or doses of medication. Binary univariate and multivariate logistic regression analyses were undertaken to examine factors associated with patient-reported safety incidents. Results Safety incidents were reported by 11% of the patients. Four factors were significantly associated with patient-reported safety incidents in multivariate analyses. The experience of multiple long-term conditions (OR=1.09, 95% CI 1.05 to 1.13), a probable diagnosis of depression (OR=1.36, 95% CI 1.06 to 1.74) and greater relational continuity of care (OR=1.28, 95% CI 1.08 to 1.52) were associated with increased odds for patient-reported safety incidents. Perceived greater support and involvement in self-management was associated with lower odds for patient-reported safety incidents (OR=0.95, 95% CI 0.93 to 0.97). Conclusions We found that older patients with multimorbidity and depression are more likely to report experiences of patient safety incidents. Improving perceived support and involvement of patients in their care may help prevent patient-reported safety incidents. PMID:28559454

Adverse obstetric outcomes in pregnant women with uterine fibroids in China: A multicenter survey involving 112,403 deliveries

PubMed Central

Zhao, Rong; Wang, Xin; Zou, Liying; Li, Guanghui; Chen, Yi; Li, Changdong; Zhang, Weiyuan

2017-01-01

Objective To estimate the association between uterine fibroids and adverse obstetric outcomes. Methods This was a retrospective cross-sectional study of 112,403 deliveries from 14 provinces and 39 different hospitals in 2011 in mainland China. We compared pregnancy outcomes in women with and without uterine fibroids who underwent detailed second trimester obstetric ultrasonography during 18 to 22 weeks. Obstetric outcomes include cesarean delivery, breech presentation, preterm delivery, placenta previa, placental abruption, premature rupture of membranes and neonatal birthweight. Univariate analyses and multivariate logistic regression analyses were performed. Results Of 112,403 women who underwent routine obstetric survey, 3,012 (2.68%) women were identified with at least 1 fibroid. By univariate and multivariate analyses, the presence of uterine fibroids was significantly associated with cesarean delivery (Adjusted odds radio [AOR] 1.8, 95% confidence interval [CI] 1.7–2.0), breech presentation (AOR 1.3, 95% CI 1.2–1.5) and postpartum hemorrhage (AOR 1.2, 95% CI 1.1–1.4). The size of uterine fibroids and location in uterus had important effect on the mode of delivery. The rates of PPH were significantly higher with increasing size of the uterine fibroid (P<0.001). And the location of fibroid (intramural, submucosal or subserosal) also have a statistically significant impact on the risk of PPH (5.6% [subserosal] vs 4.7% [submucosal] vs 8.6% [intramural]). Conclusion Pregnant women with uterine fibroids are at increased risk for cesarean delivery, breech presentation and postpartum hemorrhage. And different characteristics of uterine fibroids affect obstetric outcomes through different ways. Such detailed information may be useful in risk-stratifying pregnant women with fibroids. PMID:29136018

Insurance status, comorbidity level, and survival among colorectal cancer patients age 18 to 64 years in the National Cancer Data Base from 2003 to 2005.

PubMed

Robbins, Anthony S; Pavluck, Alexandre L; Fedewa, Stacey A; Chen, Amy Y; Ward, Elizabeth M

2009-08-01

Previous analyses have found that insurance status is a strong predictor of survival among patients with colorectal cancer aged 18 to 64 years. We investigated whether differences in comorbidity level may account in part for the association between insurance status and survival. We used 2003 to 2005 data from the National Cancer Data Base, a national hospital-based cancer registry, to examine the relationship between baseline characteristics and overall survival at 1 year among 64,304 white and black patients with colorectal cancer. In race-specific analyses, we used Cox proportional hazards models to assess 1-year survival by insurance status, controlling first for age, stage, facility type, and neighborhood education level and income, and then further controlling for comorbidity level. RESULTS; Comorbidity level was lowest among those with private insurance, higher for those who were uninsured or insured by Medicaid, and highest for those insured by Medicare. Survival at 1 year was significantly poorer for patients without private insurance, even after adjusting for important covariates. In these multivariate models, risk of death at 1 year was approximately 50% to 90% higher for white and black patients without private insurance. Further adjustment for number of comorbidities had only a modest impact on the association between insurance status and survival. In multivariate analyses, patients with > or = three comorbid conditions had approximately 40% to 50% higher risk of death at 1 year. CONCLUSION Among white and black patients aged 18 to 64 years, differences in comorbidity level do not account for the association between insurance status and survival in patients with colorectal cancer.

Comparison of FIB-4 index and aspartate aminotransferase to platelet ratio index on carcinogenesis in chronic hepatitis B treated with entecavir

PubMed Central

Nishikawa, Hiroki; Nishijima, Norihiro; Enomoto, Hirayuki; Sakamoto, Azusa; Nasu, Akihiro; Komekado, Hideyuki; Nishimura, Takashi; Kita, Ryuichi; Kimura, Toru; Iijima, Hiroko; Nishiguchi, Shuhei; Osaki, Yukio

2017-01-01

Aims: We sought to compare the effects of FIB-4 index and aspartate aminotransferase to platelet ratio index (APRI) on hepatocellular carcinoma (HCC) incidence in chronic hepatitis B (CHB) patients undergoing entecavir (ETV) therapy. Patient and methods: A total of 338 nucleosides analogue therapy naïve CHB patients initially treated with ETV were analyzed. The optimal cutoff points in each continuous variable were determined by receiver operating curve (ROC) analysis. The effects of FIB-4 index and APRI on HCC incidence were compared using time-dependent ROC analysis and factors linked to HCC incidence were also examined using univariate and multivariate analyses. Results: There were 215 males and 123 females with the median age of 52 years and the median baseline HBV-DNA level of 6.6 log copies/ml. The median follow-up interval after the initiation of ETV therapy was 4.99 years. During the follow-up period, 33 patients (9.8%) developed HCC. The 3-, 5- 7-year cumulative HCC incidence rates in all cases were 4.4%, 9.2% and 13.5%, respectively. In the multivariate analysis, FIB-4 index revealed to be an independent predictor associated with HCC incidence, while APRI was not. In the time-dependent ROC analyses for all cases and for all subgroups analyses stratified by viral status or cirrhosis status, all area under the ROCs in each time point (2-, 3-, 4-, 5-, 6-, and 7-year) of FIB-4 index were higher than those of APRI. Conclusion: FIB-4 index rather than APRI can be a useful predictor associated with HCC development for CHB patients undergoing ETV therapy. PMID:28243319

Relationship between the prognostic value of ventilatory efficiency and age in patients with heart failure.

PubMed

Kato, Yuko; Suzuki, Shinya; Uejima, Tokuhisa; Semba, Hiroaki; Nagayama, Osamu; Hayama, Etsuko; Arita, Takuto; Yagi, Naoharu; Kano, Hiroto; Matsuno, Shunsuke; Otsuka, Takayuki; Oikawa, Yuji; Kunihara, Takashi; Yajima, Junji; Yamashita, Takeshi

2018-05-01

Background Ventilatory efficiency decreases with age. This study aimed to investigate the prognostic significance and cut-off value of the minute ventilation/carbon dioxide production (VE/VCO 2 ) slope according to age in patients with heart failure. Methods and results We analysed 1501 patients with heart failure from our observational cohort who performed maximal symptom-limited cardiopulmonary exercise testing and separated them into three age groups (≤55 years, 56-70 years and ≥71 years) in total and according to the three ejection fraction categories defined by European Society of Cardiology guidelines. The endpoint was set as heart failure events, hospitalisation for heart failure or death from heart failure. The VE/VCO 2 slope increased with age. During the median follow-up period of 4 years, 141 heart failure (9%) events occurred. In total, univariate Cox analyses showed that the VE/VCO 2 slope (cont.) was significantly related to heart failure events, while on multivariate analysis, the prognostic significance of the VE/VCO 2 slope (cont.) was poor, accompanied by a significant interaction with age ( P < 0.0001). The cut-off value of the VE/VCO 2 slope increased with the increase in age in not only the total but also the sub-ejection fraction categories. Multivariate analyses with a stepwise method adjusted for estimated glomerular filtration rate, peak oxygen consumption, atrial fibrillation and brain natriuretic peptide, showed that the predictive value of the binary VE/VCO 2 slope separated by the cut-off value varied according to age. There was a tendency for the prognostic significance to increase with age irrespective of ejection fraction. Conclusion The prognostic significance and cut-off value of the VE/VCO 2 slope may increase with advancing age.

Domestic Violence, Unwanted Pregnancy and Pregnancy Termination among Urban Women of Bangladesh

PubMed Central

2013-01-01

Objective This paper explores the relationship between domestic violence against women inflicted by husbands, unwanted pregnancy and pregnancy termination of Bangladeshi urban women. Materials and methods The study used the nationally representative 2007 Bangladesh Demographic and Health Survey (BDHS) data. The BDHS covered a representative sample of 10,996 ever married women from rural and urban areas. The BDHS used a separate module to collect information from women regarding domestic violence. The survey gathered information of domestic violence from 1,013 urban women which are the basis of the study. Simple cross tabulation, bivariate and multivariate statistical analyses were performed to analyzing data. Results Overall, the lifetime prevalence of domestic violence was 47.5%. Of the most recent pregnancies, 15.6% were unwanted and 16.0% of the women terminated pregnancy in their marital life. The multivariate binary logistic regression analyses yielded quantitatively important and reliable estimate of unwanted pregnancy and pregnancy termination. The regression analyses yielded significantly (p < 0.05) increased risk of unwanted pregnancy only for physical violence (OR = 2.35, 95% CI = 1.28-4.32) and for both physical and sexual violence (OR = 2.27, 95% CI = 1.02-5.28), and higher risk of pregnancy termination for only physical violence (OR = 1.41, 95% CI = 0.95-2.10) and for both physical and sexual violence (OR = 1.81, 95% CI = 1.07-3.04) than women who were never abused. Current age, higher parity and early marriage are also important determinants of unwanted pregnancy and pregnancy termination. Conclusion Violence against women inflicted by husbands is commonplace in Bangladesh. Any strategy to reduce the burden of unwanted pregnancy and induced abortion should include prevention of violence against women and strengthening women's sexual and reproductive health. PMID:24971097

Prophylactic Plasma Transfusion Is Not Associated With Decreased Red Blood Cell Requirements in Critically Ill Patients.

PubMed

Warner, Matthew A; Chandran, Arun; Jenkins, Gregory; Kor, Daryl J

2017-05-01

Critically ill patients frequently receive plasma transfusion under the assumptions that abnormal coagulation test results confer increased risk of bleeding and that plasma transfusion will decrease this risk. However, the effect of prophylactic plasma transfusion remains poorly understood. The objective of this study was to determine the relationship between prophylactic plasma transfusion and bleeding complications in critically ill patients. This is a retrospective cohort study of adults admitted to the intensive care unit (ICU) at a single academic institution between January 1, 2009 and December 31, 2013. Inclusion criteria included age ≥18 years and an international normalized ratio measured during ICU admission. Multivariable propensity-matched analyses were used to evaluate associations between prophylactic plasma transfusion and outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of hospital- and ICU-free days and mortality within 30 days of ICU discharge. A total of 27,561 patients were included in the investigation with 2472 (9.0%) receiving plasma therapy and 1105 (44.7%) for which plasma transfusion was prophylactic in nature. In multivariable propensity-matched analyses, patients receiving plasma had higher rates of red blood cell transfusion (odds ratio: 4.3 [95% confidence interval: 3.3-5.7], P < .001) and fewer hospital-free days (estimated % increase: -11.0% [95% confidence interval: -11.4, -10.6%], P < .001). There were no significant differences in ICU-free days or mortality. These findings appeared robust, persisting in multiple predefined sensitivity analyses. Prophylactic administration of plasma in the critically ill was not associated with improved clinical outcomes. Further investigation examining the utility of plasma transfusion in this population is warranted.

Landscape genetics of leaf-toed geckos in the tropical dry forest of northern Mexico.

PubMed

Blair, Christopher; Jiménez Arcos, Victor H; Mendez de la Cruz, Fausto R; Murphy, Robert W

2013-01-01

Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF) contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus) at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by FST and Dest. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted.

Depressive symptoms in HIV-infected and seronegative control subjects in Cameroon: Effect of age, education and gender

PubMed Central

Kanmogne, Georgette D.; Qiu, Fang; Ntone, Félicien E.; Fonsah, Julius Y.; Njamnshi, Dora M.; Kuate, Callixte T.; Doh, Roland F.; Kengne, Anne M.; Tagny, Claude T.; Nchindap, Emilienne; Kenmogne, Léopoldine; Mbanya, Dora; Cherner, Mariana; Heaton, Robert K.; Njamnshi, Alfred K.

2017-01-01

Depression is a leading cause of HIV/AIDS disease burden; it worsens health outcomes and quality of life. Addressing this problem requires accurate quantification of the extra burden of depression to HIV/AIDS in a given population, and knowledge of the baseline depression prevalence in the general population. There has been no previous study of depression in the general Cameroonian population. The current study attempts to address that important need. We used the Beck Depression Inventory-II to assess the prevalence and severity of depressive symptoms in 270 HIV-infected and seronegative Cameroonians. Univariate analyses showed a trend toward higher depressive symptoms among cases, compared to controls (p = 0.055), and among older subjects (>40 years), compared to younger subjects (≤40 years) (p = 0.059). Analysis of depression severity showed that 33.73% of cases had moderate-to-severe depressive symptoms, compared to 19.8% of controls (p<0.01). However, multivariable negative binomial regression analyses showed no effect of age, HIV status, CD4 levels, viral loads, ART, or opportunistic infections on the risk of depressive symptoms. Both univariate and multivariable regression analyses showed significantly higher risk of depressive symptoms among females compared to males; this was significant for both female controls and female cases. Female cases had significantly higher CD4 cell counts and lower viral loads, compared to males. Both univariate and multivariable regression analyses showed that lower education (≤10 years) was associated with increased risk of depressive symptoms. This study shows a high prevalence of depressive symptoms among seronegative controls and HIV-infected Cameroonians. Integrating care for mental disorders such as depression into primary health care and existing HIV/AIDS treatment programs in Cameroon may improve the wellbeing of the general population and could lower the HIV/AIDS burden. PMID:28231258

Depressive symptoms in HIV-infected and seronegative control subjects in Cameroon: Effect of age, education and gender.

PubMed

Kanmogne, Georgette D; Qiu, Fang; Ntone, Félicien E; Fonsah, Julius Y; Njamnshi, Dora M; Kuate, Callixte T; Doh, Roland F; Kengne, Anne M; Tagny, Claude T; Nchindap, Emilienne; Kenmogne, Léopoldine; Mbanya, Dora; Cherner, Mariana; Heaton, Robert K; Njamnshi, Alfred K

2017-01-01

Depression is a leading cause of HIV/AIDS disease burden; it worsens health outcomes and quality of life. Addressing this problem requires accurate quantification of the extra burden of depression to HIV/AIDS in a given population, and knowledge of the baseline depression prevalence in the general population. There has been no previous study of depression in the general Cameroonian population. The current study attempts to address that important need. We used the Beck Depression Inventory-II to assess the prevalence and severity of depressive symptoms in 270 HIV-infected and seronegative Cameroonians. Univariate analyses showed a trend toward higher depressive symptoms among cases, compared to controls (p = 0.055), and among older subjects (>40 years), compared to younger subjects (≤40 years) (p = 0.059). Analysis of depression severity showed that 33.73% of cases had moderate-to-severe depressive symptoms, compared to 19.8% of controls (p<0.01). However, multivariable negative binomial regression analyses showed no effect of age, HIV status, CD4 levels, viral loads, ART, or opportunistic infections on the risk of depressive symptoms. Both univariate and multivariable regression analyses showed significantly higher risk of depressive symptoms among females compared to males; this was significant for both female controls and female cases. Female cases had significantly higher CD4 cell counts and lower viral loads, compared to males. Both univariate and multivariable regression analyses showed that lower education (≤10 years) was associated with increased risk of depressive symptoms. This study shows a high prevalence of depressive symptoms among seronegative controls and HIV-infected Cameroonians. Integrating care for mental disorders such as depression into primary health care and existing HIV/AIDS treatment programs in Cameroon may improve the wellbeing of the general population and could lower the HIV/AIDS burden.

Comparison of Xenon-Enhanced Area-Detector CT and Krypton Ventilation SPECT/CT for Assessment of Pulmonary Functional Loss and Disease Severity in Smokers.

PubMed

Ohno, Yoshiharu; Fujisawa, Yasuko; Takenaka, Daisuke; Kaminaga, Shigeo; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

2018-02-01

The objective of this study was to compare the capability of xenon-enhanced area-detector CT (ADCT) performed with a subtraction technique and coregistered 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity in smokers. Forty-six consecutive smokers (32 men and 14 women; mean age, 67.0 years) underwent prospective unenhanced and xenon-enhanced ADCT, 81m Kr-ventilation SPECT/CT, and pulmonary function tests. Disease severity was evaluated according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification. CT-based functional lung volume (FLV), the percentage of wall area to total airway area (WA%), and ventilated FLV on xenon-enhanced ADCT and SPECT/CT were calculated for each smoker. All indexes were correlated with percentage of forced expiratory volume in 1 second (%FEV 1 ) using step-wise regression analyses, and univariate and multivariate logistic regression analyses were performed. In addition, the diagnostic accuracy of the proposed model was compared with that of each radiologic index by means of McNemar analysis. Multivariate logistic regression showed that %FEV 1 was significantly affected (r = 0.77, r 2 = 0.59) by two factors: the first factor, ventilated FLV on xenon-enhanced ADCT (p < 0.0001); and the second factor, WA% (p = 0.004). Univariate logistic regression analyses indicated that all indexes significantly affected GOLD classification (p < 0.05). Multivariate logistic regression analyses revealed that ventilated FLV on xenon-enhanced ADCT and CT-based FLV significantly influenced GOLD classification (p < 0.0001). The diagnostic accuracy of the proposed model was significantly higher than that of ventilated FLV on SPECT/CT (p = 0.03) and WA% (p = 0.008). Xenon-enhanced ADCT is more effective than 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity.

Neoadjuvant Radiotherapy: A Risk Factor for Short-Term Wound Complications after Radical Resection for Rectal Cancer?

PubMed

Holubar, Stefan D; Brickman, Rachel K; Greaves, Spencer W; Ivatury, S Joga

2016-08-01

Neoadjuvant radiotherapy (RT) for rectal cancer may increase wound complications after oncologic proctectomy. We aimed to assess the relationship between neoadjuvant RT and 30-day wound complications after radical surgery for rectal cancer. We identified rectal cancer patients (International Classification of Diseases, revision-9 [ICD-9] code 154.1) who underwent radical resection, using NSQIP from 2005 to 2010. Patients were stratified into preoperative radiation vs no radiation groups. Our primary outcome was any wound complication. The association between preoperative RT and postoperative wound complication rate was assessed by univariate, multivariable, and propensity score analyses. Of 242,670 colorectal cases, 6,297 patients were included. Of these, 2,476 (39%) received RT within 90 days preoperatively. The RT group, compared with the no RT group, received more chemotherapy within 30 days preoperatively (15.0% vs 2.5%, p < 0.0001), and had less laparoscopic (18.9% vs 25.1%, p < 0.0001) or sphincter-preserving surgery (61.8% vs 67.1%, p < 0.0001). In the univariate analyses, there was no difference in wound complications (19.6% vs 18.7%, p = 0.42) between groups. Similarly, there was no difference in overall complications (29.6% vs 29.8%, p = 0.89), return to operating room (6.7% vs 6.7%, p = 0.96), or length of stay (8.4 vs 8.4 days, p = 0.72) between the RT and no RT groups, respectively. The mortality rate in the RT group was lower on univariate analysis (0.7% vs 1.4%, p = 0.008), but was not significantly different in the multivariable analyses. Multivariable and propensity score analyses were consistent with the lack of association between preoperative RT and postoperative wound complications. Neoadjuvant radiotherapy does not appear to be an independent risk factor for wound complications after radical surgery for rectal cancer. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Does speed matter? The impact of operative time on outcome in laparoscopic surgery.

PubMed

Jackson, Timothy D; Wannares, Jeffrey J; Lancaster, R Todd; Rattner, David W; Hutter, Matthew M

2011-07-01

Controversy exists concerning the importance of operative time on patient outcomes. It is unclear whether faster is better or haste makes waste or similarly whether slower procedures represent a safe, meticulous approach or inexperienced dawdling. The objective of the present study was to determine the effect of operative time on 30-day outcomes in laparoscopic surgery. Patients who underwent laparoscopic general surgery procedures (colectomy, cholecystectomy, Nissen fundoplication, inguinal hernia, and gastric bypass) from the ACS-NSQIP 2005-2008 participant use file were identified. Exclusion criteria were defined a priori to identify same-day admission, elective procedures. Operative time was divided into deciles and summary statistics were analyzed. Univariate analyses using a Cochran-Armitage test for trend were completed. The effect of operative time on 30-day morbidity was further analyzed for each procedure type using multivariate regression controlling for case complexity and additional patient factors. Patients within the highest deciles were excluded to reduce outlier effect. A total of 76,748 elective general surgical patients who underwent laparoscopic procedures were analyzed. Univariate analyses of deciles of operative time demonstrated a statistically significant trend (p<0.0001) toward increasing odds of complications with increasing operative time for laparoscopic colectomy (n=10,135), cholecystectomy (n=37,407), Nissen fundoplication (n=4,934), and gastric bypass (n=17,842). The trend was not found to be significant for laparoscopic inguinal hernia repair (n=6,430; p=0.14). Multivariate modeling revealed the effect of operative time to remain significant after controlling for additional patient factors. Increasing operative time was associated with increased odds of complications and, therefore, it appears that speed may matter in laparoscopic surgery. These analyses are limited in their inability to adjust for all patient factors, potential confounders, and case complexities. Additional hierarchical multivariate analyses at the surgeon level would be important to examine this relationship further.

Cost-effectiveness of zoledronic acid in the prevention of skeletal-related events in patients with bone metastases secondary to advanced renal cell carcinoma: application to France, Germany, and the United Kingdom.

PubMed

Botteman, M F; Meijboom, M; Foley, I; Stephens, J M; Chen, Y M; Kaura, S

2011-12-01

The use of zoledronic acid (ZOL) has recently been shown to significantly reduce the risk of new skeletal-related events (SREs) in renal cell carcinoma (RCC) patients with bone metastases. The present exploratory study assessed the cost-effectiveness of ZOL in this population, adopting a French, German, and United Kingdom (UK) government payer perspective. This cost-effectiveness model was based on a post hoc retrospective analysis of a subset of patients with RCC who were included in a larger randomized clinical trial of patients with bone metastases secondary to a variety of cancers. In the trial, patients were randomized to receive ZOL (n = 27) or placebo (n = 19) with concomitant antineoplastic therapy every 3 weeks for 9 months (core study) plus 12 months during a study extension. Since the trial did not collect costs or data on the quality-adjusted life years (QALYs) of the patients, these outcomes had to be assumed via modeling exercises. The costs of SREs were estimated using hospital DRG tariffs. These estimates were supplemented with literature-based costs where possible. Drug, administration, and supply costs were obtained from published and internet sources. Consistent with similar economic analyses, patients were assumed to experience quality of life decrements lasting 1 month for each SRE. Uncertainty surrounding outcomes was addressed via multivariate sensitivity analyses. Patients receiving ZOL experienced 1.07 fewer SREs than patients on placebo. Patients on ZOL experienced a gain in discounted QALYs of approximately 0.1563 in France and Germany and 0.1575 in the UK. Discounted SRE-related costs were substantially lower among ZOL than placebo patients (-€ 4,196 in France, - € 3,880 in Germany, and -€ 3,355 in the UK). After taking into consideration the drug therapy costs, ZOL saved € 1,358, € 1,223, and € 719 in France, Germany, and the UK, respectively. In the multivariate sensitivity analyses, therapy with ZOL saved costs in 67-77% of simulations, depending on the country. The cost per QALY gained for ZOL versus placebo was below € 30,000 per QALY gained threshold in approximately 93-94% of multivariate sensitivity analyses simulations. The present analysis suggests that ZOL saves costs and increases QALYs compared to placebo in French, German, and UK RCC patients with bone metastases. Additional prospective research may be needed to confirm these results in a larger sample of patients.

Forensic discrimination of blue ballpoint pens on documents by laser ablation inductively coupled plasma mass spectrometry and multivariate analysis.

PubMed

Alamilla, Francisco; Calcerrada, Matías; García-Ruiz, Carmen; Torre, Mercedes

2013-05-10

The differentiation of blue ballpoint pen inks written on documents through an LA-ICP-MS methodology is proposed. Small common office paper portions containing ink strokes from 21 blue pens of known origin were cut and measured without any sample preparation. In a first step, Mg, Ca and Sr were proposed as internal standards (ISs) and used in order to normalize elemental intensities and subtract background signals from the paper. Then, specific criteria were designed and employed to identify target elements (Li, V, Mn, Co, Ni, Cu, Zn, Zr, Sn, W and Pb) which resulted independent of the IS chosen in a 98% of the cases and allowed a qualitative clustering of the samples. In a second step, an elemental-related ratio (ink ratio) based on the targets previously identified was used to obtain mass independent intensities and perform pairwise comparisons by means of multivariate statistical analyses (MANOVA, Tukey's HSD and T2 Hotelling). This treatment improved the discrimination power (DP) and provided objective results, achieving a complete differentiation among different brands and a partial differentiation within pen inks from the same brands. The designed data treatment, together with the use of multivariate statistical tools, represents an easy and useful tool for differentiating among blue ballpoint pen inks, with hardly sample destruction and without the need for methodological calibrations, being its use potentially advantageous from a forensic-practice standpoint. To test the procedure, it was applied to analyze real handwritten questioned contracts, previously studied by the Department of Forensic Document Exams of the Criminalistics Service of Civil Guard (Spain). The results showed that all questioned ink entries were clustered in the same group, being those different from the remaining ink on the document. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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.

Awareness and attitude of the public toward personalized medicine in Korea

PubMed Central

Lee, Iyn-Hyang; Kang, Hye-Young; Suh, Hae Sun; Lee, Sukhyang; Oh, Eun Sil

2018-01-01

Objectives As personalized medicine (PM) is expected to greatly improve health outcomes, efforts have recently been made for its clinical implementation in Korea. We aimed to evaluate public awareness and attitude regarding PM. Methods We performed a self-administered questionnaire survey to 703 adults, who participated in the survey on a voluntary basis. The primary outcome measures included public knowledge, attitude, and acceptance of PM. We conducted multinomial multivariate logistic analysis for outcome variables with three response categories and performed multivariate logistic regression analyses for dichotomous outcome variables. Results Only 28% of participants had knowledge that genetic factors can contribute to inter-individual variations in drug response and the definition of PM (199 out of 702). Higher family income was correlated with greater knowledge concerning PM (OR = 3.76, p = 0.034). A majority of respondents preferred integrated pharmacogenomic testing over drug-specific testing and agreed to inclusion of pharmacogenomic testing in the national health examination (64% and 77%, respectively), but only 51% were willing to pay for it. Discussion Our results identify the urgent need for public education as well as the potential health disparities in access to PM. This study helps to frame policies for implementing PM in clinical practice. PMID:29451916

Asian American Women in California: A Pooled Analysis of Predictors for Breast and Cervical Cancer Screening

PubMed Central

Breen, Nancy; Liu, Benmei; Lee, Richard; Kagawa-Singer, Marjorie

2015-01-01

Objectives. We examined patterns of cervical and breast cancer screening among Asian American women in California and assessed their screening trends over time. Methods. We pooled weighted data from 5 cycles of the California Health Interview Survey (2001, 2003, 2005, 2007, 2009) to examine breast and cervical cancer screening trends and predictors among 6 Asian nationalities. We calculated descriptive statistics, bivariate associations, multivariate logistic regressions, predictive margins, and 95% confidence intervals. Results. Multivariate analyses indicated that Papanicolaou test rates did not significantly change over time (77.9% in 2001 vs 81.2% in 2007), but mammography receipt increased among Asian American women overall (75.6% in 2001 vs 81.8% in 2009). Length of time in the United States was associated with increased breast and cervical cancer screening among all nationalities. Sociodemographic and health care access factors had varied effects, with education and insurance coverage significantly predicting screening for certain groups. Overall, we observed striking variation by nationality. Conclusions. Our results underscore the need for intervention and policy efforts that are targeted to specific Asian nationalities, recent immigrants, and individuals without health care access to increase screening rates among Asian women in California. PMID:25521898

Short leukocyte telomere length is associated with obesity in American Indians: the Strong Heart Family study.

PubMed

Chen, Shufeng; Yeh, Fawn; Lin, Jue; Matsuguchi, Tet; Blackburn, Elizabeth; Lee, Elisa T; Howard, Barbara V; Zhao, Jinying

2014-05-01

Shorter leukocyte telomere length (LTL) has been associated with a wide range of age-related disorders including cardiovascular disease (CVD) and diabetes. Obesity is an important risk factor for CVD and diabetes. The association of LTL with obesity is not well understood. This study for the first time examines the association of LTL with obesity indices including body mass index, waist circumference, percent body fat, waist-to-hip ratio, and waist-to-height ratio in 3,256 American Indians (14-93 years old, 60% women) participating in the Strong Heart Family Study. Association of LTL with each adiposity index was examined using multivariate generalized linear mixed model, adjusting for chronological age, sex, study center, education, lifestyle (smoking, alcohol consumption, and total energy intake), high-sensitivity C-reactive protein, hypertension and diabetes. Results show that obese participants had significantly shorter LTL than non-obese individuals (age-adjusted P=0.0002). Multivariate analyses demonstrate that LTL was significantly and inversely associated with all of the studied obesity parameters. Our results may shed light on the potential role of biological aging in pathogenesis of obesity and its comorbidities.

Trends in Fatalities From Distracted Driving in the United States, 1999 to 2008

PubMed Central

Stimpson, Jim P.

2010-01-01

Objectives. We examined trends in distracted driving fatalities and their relation to cell phone use and texting volume. Methods. The Fatality Analysis Reporting System (FARS) records data on all road fatalities that occurred on public roads in the United States from 1999 to 2008. We studied trends in distracted driving fatalities, driver and crash characteristics, and trends in cell phone use and texting volume. We used multivariate regression analysis to estimate the relation between state-level distracted driving fatalities and texting volumes. Results. After declining from 1999 to 2005, fatalities from distracted driving increased 28% after 2005, rising from 4572 fatalities to 5870 in 2008. Crashes increasingly involved male drivers driving alone in collisions with roadside obstructions in urban areas. By use of multivariate analyses, we predicted that increasing texting volumes resulted in more than 16 000 additional road fatalities from 2001 to 2007. Conclusions. Distracted driving is a growing public safety hazard. Specifically, the dramatic rise in texting volume since 2005 appeared to be contributing to an alarming rise in distracted driving fatalities. Legislation enacting texting bans should be paired with effective enforcement to deter drivers from using cell phones while driving. PMID:20864709

Investigating the Moisture Content of Polyamide 6 by Raman-Microscopy and Multivariate Data Analysis

NASA Astrophysics Data System (ADS)

Lechner, Tobias; Noack, Kristina; Thöne, Manuel; Amend, Philipp; Schmidt, Michael; Will, Stefan

Thermal malleability of thermoplastics results in a high product diversity in various industry sectors. However, industrial applications require a constant and high component quality. Hence, material processing such as laser welding has to consider that, e.g., the moisture content of thermoplastics influences the mechanical properties such as the tensile strength. Moreover, water evaporates during laser welding and can form pores and defects. Thus, there is a large need for non-invasive material inspection before processing. To that end, we developed a methodology based on Raman-microscopy and multivariate data analysis (MVD) to determine the moisture content of polyamide (MCP). Further, the impact of the MCP on the mechanical properties was verified. For samples with a defined variation of the MCP, xyz-Raman-scans were carried out and analysed using MVD. For reference purposes, the samples were weighted and tensile tests were performed. An evaluation by means of partial least squares regression analysis (PLSR) resulted in a prediction of the MCP with a correlation coefficient >98%. Consequently, Raman-microscopy shows large potential for developing new techniques for inspection and quality control of plastics before processing. Dedicated to Professor Alfred Leipertz on the occasion of his 70th birthday.

The effects of marine sand and gravel extraction on the sediment composition and macrofaunal community of a commercial dredging site (15 years post-dredging).

PubMed

Waye-Barker, Georgia A; McIlwaine, Paul; Lozach, Sophie; Cooper, Keith M

2015-10-15

A prediction that faunal recovery of a marine aggregate extraction site subjected to high dredging intensity was likely to take 15-20 years was investigated. Samples were collected at the high dredging intensity site and two reference sites in 2011 (15 years post-dredging). Results indicated that the high site had similar sediment characteristics to the reference sites by 2011. Macrofaunal data analyses showed no difference between the values of all calculated univariate measures (abundance, number of taxa, biomass and evenness) between the high and reference sites. Multivariate analyses found that the macrofaunal community at the high site was comparable to those of the reference sites by 2011. Overall, the results supported the predicted recovery time. The findings of the study suggest that persistent physical impacts prolonged the biological recovery of the high site. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Development and validation of prognostic models in metastatic breast cancer: a GOCS study.

PubMed

Rabinovich, M; Vallejo, C; Bianco, A; Perez, J; Machiavelli, M; Leone, B; Romero, A; Rodriguez, R; Cuevas, M; Dansky, C

1992-01-01

The significance of several prognostic factors and the magnitude of their influence on response rate and survival were assessed by means of uni- and multivariate analyses in 362 patients with stage IV (UICC) breast carcinoma receiving combination chemotherapy as first systemic treatment over an 8-year period. Univariate analyses identified performance status and prior adjuvant radiotherapy as predictors of objective regression (OR), whereas the performance status, prior chemotherapy and radiotherapy (adjuvants), white blood cells count, SGOT and SGPT levels, and metastatic pattern were significantly correlated to survival. In multivariate analyses favorable characteristics associated to OR were prior adjuvant radiotherapy, no prior chemotherapy and postmenopausal status. Regarding survival, the performance status and visceral involvement were selected by the Cox model. The predictive accuracy of the logistic and the proportional hazards models was retrospectively tested in the training sample, and prospectively in a new population of 126 patients also receiving combined chemotherapy as first treatment for metastatic breast cancer. A certain overfitting to data in the training sample was observed with the regression model for response. However, the discriminative ability of the Cox model for survival was clearly confirmed.

Assessment of self-organizing maps to analyze sole-carbon source utilization profiles.

PubMed

Leflaive, Joséphine; Céréghino, Régis; Danger, Michaël; Lacroix, Gérard; Ten-Hage, Loïc

2005-07-01

The use of community-level physiological profiles obtained with Biolog microplates is widely employed to consider the functional diversity of bacterial communities. Biolog produces a great amount of data which analysis has been the subject of many studies. In most cases, after some transformations, these data were investigated with classical multivariate analyses. Here we provided an alternative to this method, that is the use of an artificial intelligence technique, the Self-Organizing Maps (SOM, unsupervised neural network). We used data from a microcosm study of algae-associated bacterial communities placed in various nutritive conditions. Analyses were carried out on the net absorbances at two incubation times for each substrates and on the chemical guild categorization of the total bacterial activity. Compared to Principal Components Analysis and cluster analysis, SOM appeared as a valuable tool for community classification, and to establish clear relationships between clusters of bacterial communities and sole-carbon sources utilization. Specifically, SOM offered a clear bidimensional projection of a relatively large volume of data and were easier to interpret than plots commonly obtained with multivariate analyses. They would be recommended to pattern the temporal evolution of communities' functional diversity.

Exploring the facilitators and barriers to engagement in physical activity for people with multiple sclerosis.

PubMed

Kayes, Nicola M; McPherson, Kathryn M; Schluter, Philip; Taylor, Denise; Leete, Marta; Kolt, Gregory S

2011-01-01

To explore the relationship that cognitive behavioural and other previously identified variables have with physical activity engagement in people with multiple sclerosis (MS). This study adopted a cross-sectional questionnaire design. Participants were 282 individuals with MS. Outcome measures included the Physical Activity Disability Survey--Revised, Cognitive and Behavioural Responses to Symptoms Questionnaire, Barriers to Health Promoting Activities for Disabled Persons Scale, Multiple Sclerosis Self-efficacy Scale, Self-Efficacy for Chronic Diseases Scales and Chalder Fatigue Questionnaire. Multivariable stepwise regression analyses found that greater self-efficacy, greater reported mental fatigue and lower number of perceived barriers to physical activity accounted for a significant proportion of variance in physical activity behaviour, over that accounted for by illness-related variables. Although fear-avoidance beliefs accounted for a significant proportion of variance in the initial analyses, its effect was explained by other factors in the final multivariable analyses. Self-efficacy, mental fatigue and perceived barriers to physical activity are potentially modifiable variables which could be incorporated into interventions designed to improve physical activity engagement. Future research should explore whether a measurement tool tailored to capture beliefs about physical activity identified by people with MS would better predict participation in physical activity.

Graduate Social Work Faculty's Support for Educational Content on Women and on Sexism.

PubMed

Levin, Dana S; Woodford, Michael R; Gutiérrez, Lorraine M; Luke, Katherine P

2015-10-01

Social work faculty play an important role in preparing students to address sexism and engage in culturally competent practice with women. This study examines the nature of U.S. and Anglo-Canadian graduate social work faculty's support for content on women and on sexism. Although support appears high for both content areas, results suggest that faculty endorsement for content on women is significantly greater than that for sexism. Further, bivariate and multivariate analyses indicate that the nature of support differs for each content area. Implications for social work education are discussed.

Intakes of caffeine, coffee and tea and risk of amyotrophic lateral sclerosis: Results from five cohort studies.

PubMed

Fondell, Elinor; O'Reilly, É Ilis J; Fitzgerald, Kathryn C; Falcone, Guido J; Kolonel, Laurence N; Park, Yikyung; Gapstur, Susan M; Ascherio, Alberto

2015-01-01

Caffeine is thought to be neuroprotective by antagonizing the adenosine A2A receptors in the brain and thereby protecting motor neurons from excitotoxicity. We examined the association between consumption of caffeine, coffee and tea and risk of amyotrophic lateral sclerosis (ALS). Longitudinal analyses based on over 1,010,000 males and females in five large cohort studies (the Nurses' Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the National Institutes of Health-AARP Diet and Health Study). Cohort-specific multivariable-adjusted risk ratios (RR) and 95% confidence intervals (CI) estimates of ALS incidence or death were estimated by Cox proportional hazards regression and pooled using random-effects models. Results showed that a total of 1279 cases of ALS were documented during a mean of 18 years of follow-up. Caffeine intake was not associated with ALS risk; the pooled multivariable-adjusted RR comparing the highest to the lowest quintile of intake was 0.96 (95% CI 0.81-1.16). Similarly, neither coffee nor tea was associated with ALS risk. In conclusion, the results of this large study do not support associations of caffeine or caffeinated beverages with ALS risk.

Intakes of caffeine, coffee and tea and risk of Amyotrophic Lateral Sclerosis: Results from five cohort studies

PubMed Central

Fondell, Elinor; O'Reilly, Éilis J.; Fitzgerald, Kathryn C.; Falcone, Guido J.; Kolonel, Laurence N.; Park, Yikyung; Gapstur, Susan M.; Ascherio, Alberto

2015-01-01

Objective Caffeine is thought to be neuroprotective by antagonizing the adenosine A2A receptors in the brain and thereby protecting motor neurons from excitotoxicity. We examined the association between consumption of caffeine, coffee and tea and risk of Amyotrophic Lateral Sclerosis (ALS). Methods Longitudinal analyses based on over 1 010 000 men and women in 5 large cohort studies [the Nurses’ Health Study, the Health Professionals Follow-up Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort Study, and the National Institutes of Health – AARP Diet and Health Study]. Cohort-specific multivariable-adjusted risk ratios (RR) and 95% confidence intervals (CI) estimates of ALS incidence or death was estimated by Cox proportional hazards regression and pooled using random-effects models. Results A total of 1279 cases of ALS were documented during a mean of 18 years of follow-up. Caffeine intake was not associated with ALS risk; the pooled multivariable-adjusted RR comparing the highest to the lowest quintile of intake was 0.96 (95% CI 0.81-1.16). Similarly, neither coffee nor tea was associated with ALS risk. Conclusion The results of this large study do not support associations of caffeine or caffeinated beverages with ALS risk. PMID:25822002

Breakthrough seizures—Further analysis of the Standard versus New Antiepileptic Drugs (SANAD) study

PubMed Central

Powell, Graham A.; Tudur Smith, Catrin; Marson, Anthony G.

2017-01-01

Objectives To develop prognostic models for risk of a breakthrough seizure, risk of seizure recurrence after a breakthrough seizure, and likelihood of achieving 12-month remission following a breakthrough seizure. A breakthrough seizure is one that occurs following at least 12 months remission whilst on treatment. Methods We analysed data from the SANAD study. This long-term randomised trial compared treatments for participants with newly diagnosed epilepsy. Multivariable Cox models investigated how clinical factors affect the probability of each outcome. Best fitting multivariable models were produced with variable reduction by Akaike’s Information Criterion. Risks associated with combinations of risk factors were calculated from each multivariable model. Results Significant factors in the multivariable model for risk of a breakthrough seizure following 12-month remission were number of tonic-clonic seizures by achievement of 12-month remission, time taken to achieve 12-month remission, and neurological insult. Significant factors in the model for risk of seizure recurrence following a breakthrough seizure were total number of drugs attempted to achieve 12-month remission, time to achieve 12-month remission prior to breakthrough seizure, and breakthrough seizure treatment decision. Significant factors in the model for likelihood of achieving 12-month remission after a breakthrough seizure were gender, age at breakthrough seizure, time to achieve 12-month remission prior to breakthrough, and breakthrough seizure treatment decision. Conclusions This is the first analysis to consider risk of a breakthrough seizure and subsequent outcomes. The described models can be used to identify people most likely to have a breakthrough seizure, a seizure recurrence following a breakthrough seizure, and to achieve 12-month remission following a breakthrough seizure. The results suggest that focussing on achieving 12-month remission swiftly represents the best therapeutic aim to reduce the risk of a breakthrough seizure and subsequent negative outcomes. This will aid individual patient risk stratification and the design of future epilepsy trials. PMID:29267375

Understanding adaptive gait in lower-limb amputees: insights from multivariate analyses

PubMed Central

2013-01-01

Background In this paper we use multivariate statistical techniques to gain insights into how adaptive gait involving obstacle crossing is regulated in lower-limb amputees compared to able-bodied controls, with the aim of identifying underlying characteristics that differ between the two groups and consequently highlighting gait deficits in the amputees. Methods Eight unilateral trans-tibial amputees and twelve able-bodied controls completed adaptive gait trials involving negotiating various height obstacles; with amputees leading with their prosthetic limb. Spatiotemporal variables that are regularly used to quantify how gait is adapted when crossing obstacles were determined and subsequently analysed using multivariate statistical techniques. Results and discussion There were fundamental differences in the adaptive gait between the two groups. Compared to controls, amputees had a reduced approach velocity, reduced foot placement distance before and after the obstacle and reduced foot clearance over it, and reduced lead-limb knee flexion during the step following crossing. Logistic regression analysis highlighted the variables that best distinguished between the gait of the two groups and multiple regression analysis (with approach velocity as a controlling factor) helped identify what gait adaptations were driving the differences seen in these variables. Getting closer to the obstacle before crossing it appeared to be a strategy to ensure the heel of the lead-limb foot passed over the obstacle prior to the foot being lowered to the ground. Despite adopting such a heel clearance strategy, the lead-foot was positioned closer to the obstacle following crossing, which was likely a result of a desire to attain a limb/foot angle and orientation at instant of landing that minimised loads on the residuum (as evidenced by the reduced lead-limb knee flexion during the step following crossing). These changes in foot placement meant the foot was in a different part of swing at point of crossing and this explains why foot clearance was considerably reduced in amputees. Conclusions These results highlight that trans-tibial amputees use quite different gait adaptations to cross obstacles compared with controls (at least when leading with their prosthetic limb), indicating they are governed by different constraints; seemingly related to how they land on/load their prosthesis after crossing the obstacle. PMID:23958032

Low health literacy predicts decline in physical function among older adults: findings from the LitCog cohort study

PubMed Central

Smith, Samuel G; O'Conor, Rachel; Curtis, Laura M; Waite, Katie; Deary, Ian J; Paasche-Orlow, Michael; Wolf, Michael S

2015-01-01

Background Limited health literacy is associated with worse physical function in cross-sectional studies. We aimed to determine if health literacy is a risk factor for decline in physical function among older adults. Methods A longitudinal cohort of 529 community-dwelling American adults aged 55–74 years were recruited from an academic general internal medicine clinic and federally qualified health centres in 2008–2011. Health literacy (Newest Vital Sign), age, gender, race, education, chronic conditions, body mass index, alcohol consumption, smoking status and exercise frequency were included in multivariable analyses. The 10-item PROMIS (Patient-Reported Outcomes Measurement Information System) physical function scale was assessed at baseline and follow-up (mean=3.2 years, SD=0.39). Results Nearly half of the sample (48.2%) had either marginal (25.5%) or low health literacy (22.7%). Average physical function at baseline was 83.2 (SD=16.6) of 100, and health literacy was associated with poorer baseline physical function in multivariable analysis (p=0.004). At follow-up, physical function declined to 81.9 (SD=17.3; p=0.006) and 20.5% experienced a meaningful decline (>0.5 SD of baseline score). In multivariable analyses, participants with marginal (OR 2.62; 95%CI 1.38 to 4.95; p=0.003) and low (OR 2.57; 95%CI 1.22 to 5.44; p=0.013) health literacy were more likely to experience meaningful decline in physical function than the adequate health literacy group. Entering cognitive abilities to these models did not substantially attenuate effect sizes. Health literacy attenuated the relationship between black race and decline in physical function by 32.6%. Conclusions Lower health literacy increases the risk of exhibiting faster physical decline over time among older adults. Strategies that reduce literacy disparities should be designed and evaluated. PMID:25573701

Decoding the Traumatic Memory among Women with PTSD: Implications for Neurocircuitry Models of PTSD and Real-Time fMRI Neurofeedback

PubMed Central

Cisler, Josh M.; Bush, Keith; James, G. Andrew; Smitherman, Sonet; Kilts, Clinton D.

2015-01-01

Posttraumatic Stress Disorder (PTSD) is characterized by intrusive recall of the traumatic memory. While numerous studies have investigated the neural processing mechanisms engaged during trauma memory recall in PTSD, these analyses have only focused on group-level contrasts that reveal little about the predictive validity of the identified brain regions. By contrast, a multivariate pattern analysis (MVPA) approach towards identifying the neural mechanisms engaged during trauma memory recall would entail testing whether a multivariate set of brain regions is reliably predictive of (i.e., discriminates) whether an individual is engaging in trauma or non-trauma memory recall. Here, we use a MVPA approach to test 1) whether trauma memory vs neutral memory recall can be predicted reliably using a multivariate set of brain regions among women with PTSD related to assaultive violence exposure (N=16), 2) the methodological parameters (e.g., spatial smoothing, number of memory recall repetitions, etc.) that optimize classification accuracy and reproducibility of the feature weight spatial maps, and 3) the correspondence between brain regions that discriminate trauma memory recall and the brain regions predicted by neurocircuitry models of PTSD. Cross-validation classification accuracy was significantly above chance for all methodological permutations tested; mean accuracy across participants was 76% for the methodological parameters selected as optimal for both efficiency and accuracy. Classification accuracy was significantly better for a voxel-wise approach relative to voxels within restricted regions-of-interest (ROIs); classification accuracy did not differ when using PTSD-related ROIs compared to randomly generated ROIs. ROI-based analyses suggested the reliable involvement of the left hippocampus in discriminating memory recall across participants and that the contribution of the left amygdala to the decision function was dependent upon PTSD symptom severity. These results have methodological implications for real-time fMRI neurofeedback of the trauma memory in PTSD and conceptual implications for neurocircuitry models of PTSD that attempt to explain core neural processing mechanisms mediating PTSD. PMID:26241958

A Polymorphism within the Vitamin D Transporter Gene Predicts Outcome in Metastatic Colorectal Cancer Patients Treated with FOLFIRI/Bevacizumab or FOLFIRI/Cetuximab.

PubMed

Berger, Martin D; Stintzing, Sebastian; Heinemann, Volker; Cao, Shu; Yang, Dongyun; Sunakawa, Yu; Matsusaka, Satoshi; Ning, Yan; Okazaki, Satoshi; Miyamoto, Yuji; Suenaga, Mitsukuni; Schirripa, Marta; Hanna, Diana L; Soni, Shivani; Puccini, Alberto; Zhang, Wu; Cremolini, Chiara; Falcone, Alfredo; Loupakis, Fotios; Lenz, Heinz-Josef

2018-02-15

Purpose: Vitamin D exerts its inhibitory influence on colon cancer growth by inhibiting Wnt signaling and angiogenesis. We hypothesized that SNPs in genes involved in vitamin D transport, metabolism, and signaling are associated with outcome in metastatic colorectal cancer (mCRC) patients treated with first-line FOLFIRI and bevacizumab. Experimental Design: 522 mCRC patients enrolled in the FIRE-3 (discovery cohort) and TRIBE (validation set) trials treated with FOLFIRI/bevacizumab were included in this study. 278 patients receiving FOLFIRI and cetuximab (FIRE-3) served as a control cohort. Six SNPs in 6 genes ( GC, CYP24A1, CYP27B1, VDR, DKK1, CST5 ) were analyzed. Results: In the discovery cohort, AA carriers of the GC rs4588 SNP encoding for the vitamin D-binding protein, and treated with FOLFIRI/bevacizumab had a shorter overall survival (OS) than those harboring any C allele (15.9 vs. 25.1 months) in both univariable ( P = 0.001) and multivariable analyses ( P = 0.047). This association was confirmed in the validation cohort in multivariable analysis (OS 18.1 vs. 26.2 months, HR, 1.83; P = 0.037). Interestingly, AA carriers in the control set exhibited a longer OS (48.0 vs. 25.2 months, HR, 0.50; P = 0.021). This association was further confirmed in a second validation cohort comprising refractory mCRC patients treated with cetuximab ± irinotecan (PFS 8.7 vs. 3.7 months) in univariable ( P = 0.033) and multivariable analyses ( P = 0.046). Conclusions: GC rs4588 SNP might serve as a predictive marker in mCRC patients treated with FOLFIRI/bevacizumab or FOLFIRI/cetuximab. Whereas AA carriers derive a survival benefit with FOLFIRI/cetuximab, treatment with FOLFIRI/bevacizumab is associated with a worse outcome. Clin Cancer Res; 24(4); 784-93. ©2017 AACR . ©2017 American Association for Cancer Research.

A perspective on two chemometrics tools: PCA and MCR, and introduction of a new one: Pattern recognition entropy (PRE), as applied to XPS and ToF-SIMS depth profiles of organic and inorganic materials

NASA Astrophysics Data System (ADS)

Chatterjee, Shiladitya; Singh, Bhupinder; Diwan, Anubhav; Lee, Zheng Rong; Engelhard, Mark H.; Terry, Jeff; Tolley, H. Dennis; Gallagher, Neal B.; Linford, Matthew R.

2018-03-01

X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are much used analytical techniques that provide information about the outermost atomic and molecular layers of materials. In this work, we discuss the application of multivariate spectral techniques, including principal component analysis (PCA) and multivariate curve resolution (MCR), to the analysis of XPS and ToF-SIMS depth profiles. Multivariate analyses often provide insight into data sets that is not easily obtained in a univariate fashion. Pattern recognition entropy (PRE), which has its roots in Shannon's information theory, is also introduced. This approach is not the same as the mutual information/entropy approaches sometimes used in data processing. A discussion of the theory of each technique is presented. PCA, MCR, and PRE are applied to four different data sets obtained from: a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized C3F6 on Si, a ToF-SIMS depth profile through ca. 100 nm of plasma polymerized PNIPAM (poly (N-isopropylacrylamide)) on Si, an XPS depth profile through a film of SiO2 on Si, and an XPS depth profile through a film of Ta2O5 on Ta. PCA, MCR, and PRE reveal the presence of interfaces in the films, and often indicate that the first few scans in the depth profiles are different from those that follow. PRE and backward difference PRE provide this information in a straightforward fashion. Rises in the PRE signals at interfaces suggest greater complexity to the corresponding spectra. Results from PCA, especially for the higher principal components, were sometimes difficult to understand. MCR analyses were generally more interpretable.

Changes of visual-field global indices after cataract surgery in primary open-angle glaucoma patients.

PubMed

Seol, Bo Ram; Jeoung, Jin Wook; Park, Ki Ho

2016-11-01

To determine changes of visual-field (VF) global indices after cataract surgery and the factors associated with the effect of cataracts on those indices in primary open-angle glaucoma (POAG) patients. A retrospective chart review of 60 POAG patients who had undergone phacoemulsification and intraocular lens insertion was conducted. All of the patients were evaluated with standard automated perimetry (SAP; 30-2 Swedish interactive threshold algorithm; Carl Zeiss Meditec Inc.) before and after surgery. VF global indices before surgery were compared with those after surgery. The best-corrected visual acuity, intraocular pressure (IOP), number of glaucoma medications before surgery, mean total deviation (TD) values, mean pattern deviation (PD) value, and mean TD-PD value were also compared with the corresponding postoperative values. Additionally, postoperative peak IOP and mean IOP were evaluated. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with the effect of cataract on global indices. Mean deviation (MD) after cataract surgery was significantly improved compared with the preoperative MD. Pattern standard deviation (PSD) and visual-field index (VFI) after surgery were similar to those before surgery. Also, mean TD and mean TD-PD were significantly improved after surgery. The posterior subcapsular cataract (PSC) type showed greater MD changes than did the non-PSC type in both the univariate and multivariate logistic regression analyses. In the univariate logistic regression analysis, the preoperative TD-PD value and type of cataract were associated with MD change. However, in the multivariate logistic regression analysis, type of cataract was the only associated factor. None of the other factors was associated with MD change. MD was significantly affected by cataracts, whereas PSD and VFI were not. Most notably, the PSC type showed better MD improvement compared with the non-PSC type after cataract surgery. Clinicians therefore should carefully analyze VF examination results for POAG patients with the PSC type.

Decoding the Traumatic Memory among Women with PTSD: Implications for Neurocircuitry Models of PTSD and Real-Time fMRI Neurofeedback.

PubMed

Cisler, Josh M; Bush, Keith; James, G Andrew; Smitherman, Sonet; Kilts, Clinton D

2015-01-01

Posttraumatic Stress Disorder (PTSD) is characterized by intrusive recall of the traumatic memory. While numerous studies have investigated the neural processing mechanisms engaged during trauma memory recall in PTSD, these analyses have only focused on group-level contrasts that reveal little about the predictive validity of the identified brain regions. By contrast, a multivariate pattern analysis (MVPA) approach towards identifying the neural mechanisms engaged during trauma memory recall would entail testing whether a multivariate set of brain regions is reliably predictive of (i.e., discriminates) whether an individual is engaging in trauma or non-trauma memory recall. Here, we use a MVPA approach to test 1) whether trauma memory vs neutral memory recall can be predicted reliably using a multivariate set of brain regions among women with PTSD related to assaultive violence exposure (N=16), 2) the methodological parameters (e.g., spatial smoothing, number of memory recall repetitions, etc.) that optimize classification accuracy and reproducibility of the feature weight spatial maps, and 3) the correspondence between brain regions that discriminate trauma memory recall and the brain regions predicted by neurocircuitry models of PTSD. Cross-validation classification accuracy was significantly above chance for all methodological permutations tested; mean accuracy across participants was 76% for the methodological parameters selected as optimal for both efficiency and accuracy. Classification accuracy was significantly better for a voxel-wise approach relative to voxels within restricted regions-of-interest (ROIs); classification accuracy did not differ when using PTSD-related ROIs compared to randomly generated ROIs. ROI-based analyses suggested the reliable involvement of the left hippocampus in discriminating memory recall across participants and that the contribution of the left amygdala to the decision function was dependent upon PTSD symptom severity. These results have methodological implications for real-time fMRI neurofeedback of the trauma memory in PTSD and conceptual implications for neurocircuitry models of PTSD that attempt to explain core neural processing mechanisms mediating PTSD.

Environmental Drivers of Benthic Flux Variation and Ecosystem Functioning in Salish Sea and Northeast Pacific Sediments.

PubMed

Belley, Rénald; Snelgrove, Paul V R; Archambault, Philippe; Juniper, S Kim

2016-01-01

The upwelling of deep waters from the oxygen minimum zone in the Northeast Pacific from the continental slope to the shelf and into the Salish Sea during spring and summer offers a unique opportunity to study ecosystem functioning in the form of benthic fluxes along natural gradients. Using the ROV ROPOS we collected sediment cores from 10 sites in May and July 2011, and September 2013 to perform shipboard incubations and flux measurements. Specifically, we measured benthic fluxes of oxygen and nutrients to evaluate potential environmental drivers of benthic flux variation and ecosystem functioning along natural gradients of temperature and bottom water dissolved oxygen concentrations. The range of temperature and dissolved oxygen encountered across our study sites allowed us to apply a suite of multivariate analyses rarely used in flux studies to identify bottom water temperature as the primary environmental driver of benthic flux variation and organic matter remineralization. Redundancy analysis revealed that bottom water characteristics (temperature and dissolved oxygen), quality of organic matter (chl a:phaeo and C:N ratios) and sediment characteristics (mean grain size and porosity) explained 51.5% of benthic flux variation. Multivariate analyses identified significant spatial and temporal variation in benthic fluxes, demonstrating key differences between the Northeast Pacific and Salish Sea. Moreover, Northeast Pacific slope fluxes were generally lower than shelf fluxes. Spatial and temporal variation in benthic fluxes in the Salish Sea were driven primarily by differences in temperature and quality of organic matter on the seafloor following phytoplankton blooms. These results demonstrate the utility of multivariate approaches in differentiating among potential drivers of seafloor ecosystem functioning, and indicate that current and future predictive models of organic matter remineralization and ecosystem functioning of soft-muddy shelf and slope seafloor habitats should consider bottom water temperature variation. Bottom temperature has important implications for estimates of seasonal and spatial benthic flux variation, benthic-pelagic coupling, and impacts of predicted ocean warming at high latitudes.

Combined high-field intraoperative magnetic resonance imaging and endoscopy increase extent of resection and progression-free survival for pituitary adenomas

PubMed Central

Sylvester, Peter T.; Evans, John A.; Zipfel, Gregory J.; Chole, Richard A.; Uppaluri, Ravindra; Haughey, Bruce H.; Getz, Anne E.; Silverstein, Julie; Rich, Keith M.; Kim, Albert H.; Dacey, Ralph G.

2014-01-01

Purpose The clinical benefit of combined intraoperative magnetic resonance imaging (iMRI) and endoscopy for transsphenoidal pituitary adenoma resection has not been completely characterized. This study assessed the impact of microscopy, endoscopy, and/or iMRI on progression-free survival, extent of resection status (gross-, near-, and subtotal resection), and operative complications. Methods Retrospective analyses were performed on 446 transsphenoidal pituitary adenoma surgeries at a single institution between 1998 and 2012. Multivariate analyses were used to control for baseline characteristics, differences during extent of resection status, and progression-free survival analysis. Results Additional surgery was performed after iMRI in 56/156 cases (35.9 %), which led to increased extent of resection status in 15/156 cases (9.6 %). Multivariate ordinal logistic regression revealed no increase in extent of resection status following iMRI or endoscopy alone; however, combining these modalities increased extent of resection status (odds ratio 2.05, 95 % CI 1.21–3.46) compared to conventional transsphenoidal microsurgery. Multivariate Cox regression revealed that reduced extent of resection status shortened progression-free survival for near- versus gross-total resection [hazard ratio (HR) 2.87, 95 % CI 1.24–6.65] and sub- versus near-total resection (HR 2.10; 95 % CI 1.00–4.40). Complication comparisons between microscopy, endoscopy, and iMRI revealed increased perioperative deaths for endoscopy versus microscopy (4/209 and 0/237, respectively), but this difference was non-significant considering multiple post hoc comparisons (Fisher exact, p = 0.24). Conclusions Combined use of endoscopy and iMRI increased pituitary adenoma extent of resection status compared to conventional transsphenoidal microsurgery, and increased extent of resection status was associated with longer progression-free survival. Treatment modality combination did not significantly impact complication rate. PMID:24599833

Direct to consumer and physician promotion of tegaserod correlated with physician visits, diagnoses, and prescriptions

PubMed Central

Dorn, Spencer D.; Farley, Joel F.; Hansen, Richard A.; D. Shah, Nilay; Sandler, Robert S.

2009-01-01

Background & Aims Direct to consumer advertisement (DTCA) and physician promotion of drugs can influence patient and physician behaviors. We sought to determine the relationship between promotion of tegaserod and the number of office visits for abdominal pain, constipation, and bloating; diagnoses of irritable bowel syndrome (IBS); and tegaserod prescriptions. Methods We used an Integrated Promotional Services database to estimate tegaserod DTCA and promotion expenditures, The National Ambulatory/Hospital Medical Care Surveys (1997–2005) to estimate the number of ambulatory care visits for abdominal pain, constipation, and bloating and diagnoses of IBS, and IMS Health's National Prescription Audit Plus to estimate the number of prescriptions. We constructed segmented and multivariate regression models to analyze the data. Results In the 3 months immediately following the start of tegaserod DTCA, there was a significant increase in physician visits (by 1 million; 95% CI 0.5–1.6 million) and IBS diagnoses (by 397,025; 95% CI 3,909–790,141). Subsequently, the trend of visits and IBS diagnoses reduced. In multivariate analyses that examined the overall relationship of promotion with visits, diagnoses, and prescriptions, only the relationship between physician promotion and tegaserod prescribing was significant; every $1 million spent on physician promotion resulted in an additional 4,108 prescriptions (95% CI: 2,526–5,691). Conclusions The initial DTCA of tegaserod was associated with a significant, immediate increase in physician visits and IBS diagnoses. This trend reversed and in multivariate models, neither DTCA nor physician promotion correlated with visits or diagnoses. Physician promotion (though not DTCA) correlated with tegaserod prescription volume. PMID:19445943

Relationship between hunger, adherence to antiretroviral therapy and plasma HIV RNA suppression among HIV-positive illicit drug users in a Canadian setting.

PubMed

Anema, Aranka; Kerr, Thomas; Milloy, M-J; Feng, Cindy; Montaner, Julio S G; Wood, Evan

2014-04-01

Food insecurity may be a barrier to achieving optimal HIV treatment-related outcomes among illicit drug users. This study therefore, aimed to assess the impact of severe food insecurity, or hunger, on plasma HIV RNA suppression among illicit drug users receiving antiretroviral therapy (ART). A cross-sectional Multivariate logistic regression model was used to assess the potential relationship between hunger and plasma HIV RNA suppression. A sample of n = 406 adults was derived from a community-recruited open prospective cohort of HIV-positive illicit drug users, in Vancouver, British Columbia (BC), Canada. A total of 235 (63.7%) reported "being hungry and unable to afford enough food," and 241 (59.4%) had plasma HIV RNA < 50 copies/ml. In unadjusted analyses, self-reported hunger was associated with lower odds of plasma HIV RNA suppression (Odds Ratio = 0.59, 95% confidence interval [CI]: 0.39-0.90, p = 0.015). In multivariate analyses, this association was no longer significant after controlling for socio-demographic, behavioral, and clinical characteristics, including 95% adherence (Adjusted Odds Ratio [AOR] = 0.65, 95% CI: 0.37-1.10, p = 0.105). Multivariate models stratified by 95% adherence found that the direction and magnitude of this association was not significantly altered by the adherence level. Hunger was common among illicit drug users in this setting. Although, there was an association between hunger and lower likelihood of plasma HIV RNA suppression, this did not persist in adjusted analyses. Further research is warranted to understand the social-structural, policy, and physical factors shaping the HIV outcomes of illicit drug users.

Risk factors for microbial bioburden during daily wear of silicone hydrogel contact lenses.

PubMed

Jiang, Ying; Jacobs, Michael; Bajaksouzian, Saralee; Foster, Altreisha N; Debanne, Sara M; Bielefeld, Roger; Garvey, Matt; Raghupathy, Sangeetha; Kern, Jami; Szczotka-Flynn, Loretta B

2014-05-01

To assess risk factors associated with substantial microbial bioburden of lids, conjunctivae, contact lenses, and storage cases during daily wear of silicone hydrogel contact lenses. Two hundred eighteen patients were fit to lotrafilcon A lenses, randomized to use either a multipurpose solution or a hydrogen peroxide care system, and followed up for 1 year. Lenses, lens transport saline, lids, conjunctivae, and storage cases were cultured and considered to have substantial microbial bioburden when they harbored high levels of commensal or pathogenic organisms. Univariate and multivariate logistic regression analyses were conducted to examine which demographic covariates were associated with significant bioburden at each location while controlling for solution use. In multivariate analyses, smoking trended toward an association with lens bioburden (odds ratio [OR]=2.15, 95% confidence interval [CI]: 0.95-4.88). Clerical occupations were found to be associated with more frequent overall storage case contamination (OR=3.51, 95% CI: 1.15-10.70) and, specifically, higher gram-positive storage case contamination (OR=5.57, 95% CI: 1.82-17.06). The peroxide system was associated with more frequent storage case contamination (OR=7.6, 95% CI: 3.79-15.19). Coagulase-negative staphylococci (CNS) were the most frequently cultured organisms within storage cases, and in multivariate analyses, CNS were more frequently found in storage cases of peroxide users (OR=6.12, 95% CI: 2.91-13.09). Clerical occupations were associated with increased microbial bioburden of storage cases during daily wear of silicone hydrogel lenses. Smoking may increase the risk of lens contamination. Storage cases are most frequently contaminated with normal skin flora, and peroxide cases were associated with more frequent contamination. However, the solution type was not associated with lid or lens contamination nor with corneal infiltrative events in this study.

Gene set analysis using variance component tests.

PubMed

Huang, Yen-Tsung; Lin, Xihong

2013-06-28

Gene set analyses have become increasingly important in genomic research, as many complex diseases are contributed jointly by alterations of numerous genes. Genes often coordinate together as a functional repertoire, e.g., a biological pathway/network and are highly correlated. However, most of the existing gene set analysis methods do not fully account for the correlation among the genes. Here we propose to tackle this important feature of a gene set to improve statistical power in gene set analyses. We propose to model the effects of an independent variable, e.g., exposure/biological status (yes/no), on multiple gene expression values in a gene set using a multivariate linear regression model, where the correlation among the genes is explicitly modeled using a working covariance matrix. We develop TEGS (Test for the Effect of a Gene Set), a variance component test for the gene set effects by assuming a common distribution for regression coefficients in multivariate linear regression models, and calculate the p-values using permutation and a scaled chi-square approximation. We show using simulations that type I error is protected under different choices of working covariance matrices and power is improved as the working covariance approaches the true covariance. The global test is a special case of TEGS when correlation among genes in a gene set is ignored. Using both simulation data and a published diabetes dataset, we show that our test outperforms the commonly used approaches, the global test and gene set enrichment analysis (GSEA). We develop a gene set analyses method (TEGS) under the multivariate regression framework, which directly models the interdependence of the expression values in a gene set using a working covariance. TEGS outperforms two widely used methods, GSEA and global test in both simulation and a diabetes microarray data.

Factors associated with regional rheumatic pain disorders in a population of Puerto Ricans with diabetes mellitus

PubMed Central

Font, Yvonne M.; Castro-Santana, Lesliane E.; Nieves-Plaza, Mariely; Maldonado, Mirna; Mayor, Ángel M.

2015-01-01

The aim of the study was to determine the prevalence and factors associated with bursitis/tendonitis disorders in Puerto Ricans with diabetes mellitus (DM). A cross-sectional study was performed in 202 adult Puerto Ricans (100 DM patients and 102 non-diabetic subjects). For each participant, a complete medical history and a musculoskeletal exam were systematically performed. Socio-demographic parameters, health-related behaviors, comorbidities, and pharmacotherapy were determined for all subjects. For DM patients, disease duration, glycemic control, and DM long-term complications were also examined. Multivariate logistic regression analyses were used to determine the factors associated with bursitis/tendonitis disorders. The mean (SD) age for DM patients and non-diabetic controls were 53.3 (12.9) and 50.0 (13.1) years; 64.0 and 64.7 % of DM patients and controls were females, respectively. Overall, the prevalence of bursitis/tendonitis was higher in DM patients than among non-diabetics (59.0 % vs. 29.4 %, p<0.01). In multivariate analyses, DM patients had 2.47 (95 % CI 1.05, 5.84) the odds of having bursitis/tendonitis as compared to non-diabetics. Specifically, DM patients had a higher frequency of flexor tenosynovitis, De Quervain’s tenosynovitis, lateral epicondylitis, medial epicondylitis, trochanteric bursitis, and anserine bursitis than non-diabetic subjects (p<0.05). Among DM patients, multivariate analyses showed that those with bursitis/tendonitis were more likely to be female [OR (95 % CI) 4.55 (1.42, 14.55)] and have peripheral vascular disease [OR (95 % CI) 8.48 (1.71, 41.93)]. In conclusion, bursitis/tendonitis disorders were common in this population of Hispanics with DM. Among DM patients, bursitis/tendonitis disorders were more frequent in women and those with long-term complications such as peripheral vascular disease. PMID:24522480

Expression of Vascular Notch Ligand Delta-Like 4 and Inflammatory Markers in Breast Cancer

PubMed Central

Jubb, Adrian M.; Soilleux, Elizabeth J.; Turley, Helen; Steers, Graham; Parker, Andrew; Low, Irene; Blades, Jennifer; Li, Ji-Liang; Allen, Paul; Leek, Russell; Noguera-Troise, Irene; Gatter, Kevin C.; Thurston, Gavin; Harris, Adrian L.

2010-01-01

Delta-like ligand 4 (Dll4) is a Notch ligand that is predominantly expressed in the endothelium. Evidence from xenografts suggests that inhibiting Dll4 may overcome resistance to antivascular endothelial growth factor therapy. The aims of this study were to characterize the expression of Dll4 in breast cancer and assess whether it is associated with inflammatory markers and prognosis. We examined 296 breast adenocarcinomas and 38 ductal carcinoma in situ tissues that were represented in tissue microarrays. Additional whole sections representing 10 breast adenocarcinomas, 10 normal breast tissues, and 16 angiosarcomas were included. Immunohistochemistry was then performed by using validated antibodies against Dll4, CD68, CD14, Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN), CD123, neutrophil elastase, CD31, and carbonic anhydrase 9. Dll4 was selectively expressed by intratumoral endothelial cells in 73% to 100% of breast adenocarcinomas, 18% of in situ ductal carcinomas, and all lactating breast cases, but not normal nonlactating breast. High intensity of endothelial Dll4 expression was a statistically significant adverse prognostic factor in univariate (P = 0.002 and P = 0.01) and multivariate analyses (P = 0.03 and P = 0.04) of overall survival and relapse-free survival, respectively. Among the inflammatory markers, only CD68 and DC-SIGN were significant prognostic factors in univariate (but not multivariate) analyses of overall survival (P = 0.01 and 0.002, respectively). In summary, Dll4 was expressed by endothelium associated with breast cancer cells. In these retrospective subset analyses, endothelial Dll4 expression was a statistically significant multivariate prognostic factor. PMID:20167860

Utility of Intermediate-Delay Washout CT Images for Differentiation of Malignant and Benign Adrenal Lesions: A Multivariate Analysis.

PubMed

Ng, Chaan S; Altinmakas, Emre; Wei, Wei; Ghosh, Payel; Li, Xiao; Grubbs, Elizabeth G; Perrier, Nancy D; Lee, Jeffrey E; Prieto, Victor G; Hobbs, Brian P

2018-06-27

The objective of this study was to identify features that impact the diagnostic performance of intermediate-delay washout CT for distinguishing malignant from benign adrenal lesions. This retrospective study evaluated 127 pathologically proven adrenal lesions (82 malignant, 45 benign) in 126 patients who had undergone portal venous phase and intermediate-delay washout CT (1-3 minutes after portal venous phase) with or without unenhanced images. Unenhanced images were available for 103 lesions. Quantitatively, lesion CT attenuation on unenhanced (UA) and delayed (DL) images, absolute and relative percentage of enhancement washout (APEW and RPEW, respectively), descriptive CT features (lesion size, margin characteristics, heterogeneity or homogeneity, fat, calcification), patient demographics, and medical history were evaluated for association with lesion status using multiple logistic regression with stepwise model selection. Area under the ROC curve (A z ) was calculated from both univariate and multivariate analyses. The predictive diagnostic performance of multivariate evaluations was ascertained through cross-validation. A z for DL, APEW, RPEW, and UA was 0.751, 0.795, 0.829, and 0.839, respectively. Multivariate analyses yielded the following significant CT quantitative features and associated A z when combined: RPEW and DL (A z = 0.861) when unenhanced images were not available and APEW and UA (A z = 0.889) when unenhanced images were available. Patient demographics and presence of a prior malignancy were additional significant factors, increasing A z to 0.903 and 0.927, respectively. The combined predictive classifier, without and with UA available, yielded 85.7% and 87.3% accuracies with cross-validation, respectively. When appropriately combined with other CT features, washout derived from intermediate-delay CT with or without additional clinical data has potential utility in differentiating malignant from benign adrenal lesions.

The degree of circumferential tumour involvement as a prognostic factor in oesophageal cancer.

PubMed

Sillah, Karim; Pritchard, Susan A; Watkins, Gillian R; McShane, James; West, Catharine M; Page, Richard; Welch, Ian M

2009-08-01

Tumour length is an adverse prognostic factor in oesophageal cancer. However, the prognostic role of the degree of oesophageal circumference (DOC) involved by tumour with or without resection margin invasion is not clear. This work assessed the relationship between DOC involved by tumour, clinico-pathological variables and prognosis. The clinico-pathological details of 320 patients who underwent potentially curative oesophagogastrectomy for cancer between 1994 and 2007 were analysed. The DOC involved with tumour measured macroscopically on the resected specimen was classified as small (<2.5 cm, n = 115), large (> or = 2.5 cm, n = 144) or circumferential (i.e. involving the whole circumference, n = 61). Univariate and multivariate survival analyses were carried out. The DOC with tumour was higher in ulcerating tumours than stenosing or polypoidal types (p = 0.017). Tumour length, T-stage, neoadjuvant chemotherapy and vascular invasion were independently associated with DOC with tumour on multivariate analysis (p < 0.05 for all). DOC > or = 2.5 cm was an adverse prognostic factor in univariate analysis (p = 0.002) with a hazard ratio of 1.52 [95% CI 1.13-2.04] compared with those <2.5 cm. Circumferential tumours had a similar prognosis to tumours > or = 2.5 cm (p = 0.60). The prognostic significance of DOC with tumour was lost in multivariate analysis where the factors retaining independence were patient age, T-stage, lymph node metastasis, vascular invasion and positive resection margins. However, when patients were stratified by use of neoadjuvant chemotherapy (n = 121), the DOC with tumour retained prognostic significance on multivariate analysis in the 199 patients who did not undergo neoadjuvant chemotherapy (p = 0.04). The DOC with tumour appears to provide prognostic information in oesophageal cancer surgery, especially in patients who do not undergo preoperative chemotherapy.

Angiotensin-converting enzyme inhibitor and statin use and incident mobility limitation in community-dwelling older adults: the Health, Aging and Body Composition study.

PubMed

Gray, Shelly L; Boudreau, Robert M; Newman, Anne B; Studenski, Stephanie A; Shorr, Ronald I; Bauer, Douglas C; Simonsick, Eleanor M; Hanlon, Joseph T

2011-12-01

To evaluate whether the use of angiotensin-converting enzyme (ACE) inhibitors and statins is associated with a lower risk of incident mobility limitation in older community dwelling adults. Longitudinal cohort study. Health, Aging and Body Composition (Health ABC) study. Three thousand fifty-five participants who were well functioning at baseline (no mobility limitations). Summated standardized daily doses (low, medium, high) and duration of ACE inhibitor and statin use were computed. Mobility limitation (two consecutive self-reports of having any difficulty walking one-quarter of a mile or climbing 10 steps without resting) was assessed every 6 months after baseline. Multivariable Cox proportional hazards analyses were conducted, adjusting for demographics, health status, and health behaviors. At baseline, 15.2% used ACE inhibitors and 12.9% used statins; use of both was greater than 25% by Year 6. Over 6.5 years of follow-up, 49.8% had developed mobility limitation. In separate multivariable models, neither ACE inhibitor (multivariate hazard ratio (HR) = 0.95, 95% confidence interval (CI) = 0.82-1.09) nor statin use (multivariate HR = 1.02, 95% CI = 0.87-1.17) was associated with lower risk of mobility limitation. Similar findings were seen in analyses examining dose-response and duration-response relationships and a sensitivity analysis restricted to those with hypertension. ACE inhibitors and statins widely prescribed to treat hypertension and hypercholesterolemia, respectively, do not lower risk of mobility limitation, an important indicator of quality of life. © 2011, Copyright the Authors Journal compilation © 2011, The American Geriatrics Society.

Integrated Multivariate Analysis with Nondetects for the Development of Human Sewage Source-Tracking Tools Using Bacteriophages of Enterococcus faecalis.

PubMed

Wangkahad, Bencharong; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee

2017-02-21

We developed sewage-specific microbial source tracking (MST) tools using enterococci bacteriophages and evaluated their performance with univariate and multivariate analyses involving data below detection limits. Newly isolated Enterococci faecalis bacterial strains AIM06 (DSM100702) and SR14 (DSM100701) demonstrated 100% specificity and 90% sensitivity to human sewage without detecting 68 animal manure pooled samples of cats, chickens, cows, dogs, ducks, pigs, and pigeons. AIM06 and SR14 bacteriophages were present in human sewage at 2-4 orders of magnitude. A principal component analysis confirmed the importance of both phages as main water quality parameters. The phages presented only in the polluted water, as classified by a cluster analysis, and at median concentrations of 1.71 × 10 2 and 4.27 × 10 2 PFU/100 mL, respectively, higher than nonhost specific RYC2056 phages and sewage-specific KS148 phages (p < 0.05). Interestingly, AIM06 and SR14 phages exhibited significant correlations with each other and with total coliforms, E. coli, enterococci, and biochemical oxygen demand (Kendall's tau = 0.348 to 0.605, p < 0.05), a result supporting their roles as water quality indicators. This research demonstrates the multiregional applicability of enterococci hosts in MST application and highlights the significance of multivariate analysis with nondetects in evaluating the performance of new MST host strains.

Categorical speech processing in Broca's area: an fMRI study using multivariate pattern-based analysis.

PubMed

Lee, Yune-Sang; Turkeltaub, Peter; Granger, Richard; Raizada, Rajeev D S

2012-03-14

Although much effort has been directed toward understanding the neural basis of speech processing, the neural processes involved in the categorical perception of speech have been relatively less studied, and many questions remain open. In this functional magnetic resonance imaging (fMRI) study, we probed the cortical regions mediating categorical speech perception using an advanced brain-mapping technique, whole-brain multivariate pattern-based analysis (MVPA). Normal healthy human subjects (native English speakers) were scanned while they listened to 10 consonant-vowel syllables along the /ba/-/da/ continuum. Outside of the scanner, individuals' own category boundaries were measured to divide the fMRI data into /ba/ and /da/ conditions per subject. The whole-brain MVPA revealed that Broca's area and the left pre-supplementary motor area evoked distinct neural activity patterns between the two perceptual categories (/ba/ vs /da/). Broca's area was also found when the same analysis was applied to another dataset (Raizada and Poldrack, 2007), which previously yielded the supramarginal gyrus using a univariate adaptation-fMRI paradigm. The consistent MVPA findings from two independent datasets strongly indicate that Broca's area participates in categorical speech perception, with a possible role of translating speech signals into articulatory codes. The difference in results between univariate and multivariate pattern-based analyses of the same data suggest that processes in different cortical areas along the dorsal speech perception stream are distributed on different spatial scales.

Comparing patients with spinal cord infarction and cerebral infarction: clinical characteristics, and short-term outcome

PubMed Central

Naess, Halvor; Romi, Fredrik

2011-01-01

Background: To compare the clinical characteristics, and short-term outcome of spinal cord infarction and cerebral infarction. Methods: Risk factors, concomitant diseases, neurological deficits on admission, and short-term outcome were registered among 28 patients with spinal cord infarction and 1075 patients with cerebral infarction admitted to the Department of Neurology, Haukeland University Hospital, Bergen, Norway. Multivariate analyses were performed with location of stroke (cord or brain), neurological deficits on admission, and short-term outcome (both Barthel Index [BI] 1 week after symptom onset and discharge home or to other institution) as dependent variables. Results: Multivariate analysis showed that patients with spinal cord infarction were younger, more often female, and less afflicted by hypertension and cardiac disease than patients with cerebral infarction. Functional score (BI) was lower among patients with spinal cord infarctions 1 week after onset of symptoms (P < 0.001). Odds ratio for being discharged home was 5.5 for patients with spinal cord infarction compared to cerebral infarction after adjusting for BI scored 1 week after onset (P = 0.019). Conclusion: Patients with spinal cord infarction have a risk factor profile that differs significantly from that of patients with cerebral infarction, although there are some parallels to cerebral infarction caused by atherosclerosis. Patients with spinal cord infarction were more likely to be discharged home when adjusting for early functional level on multivariate analysis. PMID:21915166

Does labour market disadvantage help to explain why childhood circumstances are related to quality of life at older ages? Results from SHARE.

PubMed

Wahrendorf, Morten; Blane, David

2015-07-01

There is robust evidence that childhood circumstances are related to quality of life in older ages, but the role of possible intermediate factors is less explored. In this paper, we examine to what extent associations between deprived childhood circumstances and quality of life at older ages are due to experienced labour market disadvantage during adulthood. Analyses are based on the Survey of Health Ageing and Retirement in Europe (SHARE), with detailed retrospective information on individual life courses collected among 10,272 retired men and women in 13 European countries (2008-2009). Our assumption is that those who have spent their childhood in deprived circumstances may also have had more labour market disadvantage with negative consequences for quality of life beyond working life. Results demonstrate that advantaged circumstances during childhood are associated with lower levels of labour market disadvantage and higher quality of life in older ages. Furthermore, results of multivariate analyses support the idea that part of the association between childhood circumstances and later quality of life is explained by labour market disadvantage during adulthood.

Sequential Linker Installation: Precise Placement of Functional Groups in Multivariate Metal-Organic Frameworks

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

Yuan, S; Lu, WG; Chen, YP

2015-03-11

A unique strategy, sequential linker installation (SLI), has been developed to construct multivariate MOFs with functional groups precisely positioned. PCN-700, a Zr-MOF with eight-connected Zr6O4(OH)(8)(H2O)(4) clusters, has been judiciously designed; the Zr-6 clusters in this MOF are arranged in such a fashion that, by replacement of terminal OH-/H2O ligands, subsequent insertion of linear dicarboxylate linkers is achieved. We demonstrate that linkers with distinct lengths and functionalities can be sequentially installed into PCN-700. Single-crystal to single-crystal transformation is realized so that the positions of the subsequently installed linkers are pinpointed via single-crystal X-ray diffraction analyses. This methodology provides a powerful toolmore » to construct multivariate MOFs with precisely positioned functionalities in the desired proximity, which would otherwise be difficult to achieve.« less

Measures of precision for dissimilarity-based multivariate analysis of ecological communities

PubMed Central

Anderson, Marti J; Santana-Garcon, Julia

2015-01-01

Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. PMID:25438826

Distinguishing nonpareil marketing group almond cultivars through multivariate analyses

USDA-ARS?s Scientific Manuscript database

More than 80% of the world’s almonds are grown in California with several dozen almond cultivars available commercially. To facilitate promotion and sale, almond cultivars are categorized into marketing groups based on kernel shape and appearance. Several marketing groups are recognized, with the ...

Parenting Characteristics Associated with Anxiety and Depression: A Multivariate Approach

ERIC Educational Resources Information Center

Anhalt, Karla; Morris, Tracy L.

2008-01-01

This study examined the association between perceived parenting factors and symptoms of social anxiety, generalized anxiety and depression. Participants rated experiences with their mothers and fathers with regard to parental care, overprotection, criticism, parent-adolescent attachment, and family sociability. Regression analyses examined the…

ASSOCIATION OF LANDSCAPE METRICS TO SURFACE WATER BIOLOGY IN THE SAVANNAH RIVER BASIN

EPA Science Inventory

Surface water quality for the Savannah River basin was assessed using water biology and landscape metrics. Two multivariate analyses, partial least square and cannonical correlation, were used to describe how the structural variation in landscape variable(s) that contribute the ...

The Impact of Asking Intention or Self-Prediction Questions on Subsequent Behavior

PubMed Central

Wood, Chantelle; Conner, Mark; Miles, Eleanor; Sandberg, Tracy; Taylor, Natalie; Godin, Gaston; Sheeran, Paschal

2015-01-01

The current meta-analysis estimated the magnitude of the impact of asking intention and self-prediction questions on rates of subsequent behavior, and examined mediators and moderators of this question–behavior effect (QBE). Random-effects meta-analysis on 116 published tests of the effect indicated that intention/prediction questions have a small positive effect on behavior (d+ = 0.24). Little support was observed for attitude accessibility, cognitive dissonance, behavioral simulation, or processing fluency explanations of the QBE. Multivariate analyses indicated significant effects of social desirability of behavior/behavior domain (larger effects for more desirable and less risky behaviors), difficulty of behavior (larger effects for easy-to-perform behaviors), and sample type (larger effects among student samples). Although this review controls for co-occurrence of moderators in multivariate analyses, future primary research should systematically vary moderators in fully factorial designs. Further primary research is also needed to unravel the mechanisms underlying different variants of the QBE. PMID:26162771

imDEV: a graphical user interface to R multivariate analysis tools in Microsoft Excel

PubMed Central

Grapov, Dmitry; Newman, John W.

2012-01-01

Summary: Interactive modules for Data Exploration and Visualization (imDEV) is a Microsoft Excel spreadsheet embedded application providing an integrated environment for the analysis of omics data through a user-friendly interface. Individual modules enables interactive and dynamic analyses of large data by interfacing R's multivariate statistics and highly customizable visualizations with the spreadsheet environment, aiding robust inferences and generating information-rich data visualizations. This tool provides access to multiple comparisons with false discovery correction, hierarchical clustering, principal and independent component analyses, partial least squares regression and discriminant analysis, through an intuitive interface for creating high-quality two- and a three-dimensional visualizations including scatter plot matrices, distribution plots, dendrograms, heat maps, biplots, trellis biplots and correlation networks. Availability and implementation: Freely available for download at http://sourceforge.net/projects/imdev/. Implemented in R and VBA and supported by Microsoft Excel (2003, 2007 and 2010). Contact: John.Newman@ars.usda.gov Supplementary Information: Installation instructions, tutorials and users manual are available at http://sourceforge.net/projects/imdev/. PMID:22815358

Geographically Sourcing Cocaine’s Origin – Delineation of the Nineteen Major Coca Growing Regions in South America

PubMed Central

Mallette, Jennifer R.; Casale, John F.; Jordan, James; Morello, David R.; Beyer, Paul M.

2016-01-01

Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses (2H and 18O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions. PMID:27006288

Glycated Hemoglobin Independently Predicts Stroke Recurrence within One Year after Acute First-Ever Non-Cardioembolic Strokes Onset in A Chinese Cohort Study

PubMed Central

Wu, Shuolin; Shi, Yuzhi; Wang, Chunxue; Jia, Qian; Zhang, Ning; Zhao, Xingquan; Liu, Gaifen; Wang, Yilong; Liu, Liping; Wang, Yongjun

2013-01-01

Objective Hyperglycemia is related to stroke. Glycated hemoglobin (HbA1c) can reflect pre-stroke glycaemia status. However, the information on the direct association between HbA1c and recurrence after non-cardioembolic acute ischemic strokes is rare and there is no consistent conclusion. Methods The ACROSS-China database comprised of 2186 consecutive first-ever acute ischemic stroke patients with baseline HbA1c values. After excluding patients who died from non-stroke recurrence and patients lost to follow up, 1817 and 1540 were eligible for 3-month and 1-year analyses, respectively. Multivariate Cox regression was performed to evaluate the associations between HbA1c and 3-month and 1-year stroke recurrence. Results The HbA1c values at admission were divided into 4 levels by quartiles: Q1 (<5.5%); Q2 (5.5 to <6.1%); Q3 (6.1% to <7.2%); and Q4 (≥7.2%). The cumulative recurrence rates were 8.3% and 11.0% for 3 months and 1 year, respectively. In multivariate analyses, when compared with Q1, the adjusted hazard ratios (AHRs) were 2.83 (95% confidence interval (CI) 1.28-6.26) in Q3 and 3.71(95% CI 1.68-8.21) in Q4 for 3-month stroke recurrence; 3.30 (95% CI 1.31-8.34) in Q3 and 3.35 (95% CI 1.36-8.21) in Q4 for 1-year stroke recurrence. Adding fasting plasma glucose in the multivariate analyses did not modify the association: AHRs were 2.75 (95% CI 1.24-6.11) in Q3 and 3.67 (95% CI 1.59-8.53) in Q4 for 3-month analysis; AHRs were 3.08 (95% CI 1.10-8.64) in Q3 and 3.31(95% CI 1.35-8.14) in Q4 for 1-year analysis. Conclusions A higher “normal” HbA1c level reflecting pre-stroke glycaemia status independently predicts stroke recurrence within one year after non-cardioembolic acute ischemic stroke onset. HbA1c is recommended as a routine test in acute ischemic stroke patients. PMID:24236195

Network Analysis of Associations between Serum Interferon Alpha Activity, Autoantibodies, and Clinical Features in Systemic Lupus Erythematosus

PubMed Central

Weckerle, Corinna E.; Franek, Beverly S.; Kelly, Jennifer A.; Kumabe, Marissa; Mikolaitis, Rachel A.; Green, Stephanie L.; Utset, Tammy O.; Jolly, Meenakshi; James, Judith A.; Harley, John B.; Niewold, Timothy B.

2010-01-01

Background Interferon-alpha (IFN-α) is a primary pathogenic factor in systemic lupus erythematosus (SLE), and high IFN-α levels may be associated with particular clinical manifestations. The prevalence of individual clinical and serologic features differs significantly by ancestry. We used multivariate and network analyses to detect associations between clinical and serologic disease manifestations and serum IFN-α activity in a large diverse SLE cohort. Methods 1089 SLE patients were studied (387 African-American, 186 Hispanic-American, and 516 European-American). Presence or absence of ACR clinical criteria for SLE, autoantibodies, and serum IFN-α activity data were analyzed in univariate and multivariate models. Iterative multivariate logistic regression was performed in each background separately to establish the network of associations between variables that were independently significant following Bonferroni correction. Results In all ancestral backgrounds, high IFN-α activity was associated with anti-Ro and anti-dsDNA antibodies (p-values 4.6×10−18 and 2.9 × 10−16 respectively). Younger age, non-European ancestry, and anti-RNP were also independently associated with increased serum IFN-α activity (p≤6.7×10−4). We found 14 unique associations between variables in network analysis, and only 7 of these associations were shared by more than one ancestral background. Associations between clinical criteria were different in different ancestral backgrounds, while autoantibody-IFN-α relationships were similar across backgrounds. IFN-α activity and autoantibodies were not associated with ACR clinical features in multivariate models. Conclusions Serum IFN-α activity was strongly and consistently associated with autoantibodies, and not independently associated with clinical features in SLE. IFN-α may be more relevant to humoral tolerance and initial pathogenesis than later clinical disease manifestations. PMID:21162028

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

Assessment of trace elements levels in patients with Type 2 diabetes using multivariate statistical analysis.

PubMed

Badran, M; Morsy, R; Soliman, H; Elnimr, T

2016-01-01

The trace elements metabolism has been reported to possess specific roles in the pathogenesis and progress of diabetes mellitus. Due to the continuous increase in the population of patients with Type 2 diabetes (T2D), this study aims to assess the levels and inter-relationships of fast blood glucose (FBG) and serum trace elements in Type 2 diabetic patients. This study was conducted on 40 Egyptian Type 2 diabetic patients and 36 healthy volunteers (Hospital of Tanta University, Tanta, Egypt). The blood serum was digested and then used to determine the levels of 24 trace elements using an inductive coupled plasma mass spectroscopy (ICP-MS). Multivariate statistical analysis depended on correlation coefficient, cluster analysis (CA) and principal component analysis (PCA), were used to analysis the data. The results exhibited significant changes in FBG and eight of trace elements, Zn, Cu, Se, Fe, Mn, Cr, Mg, and As, levels in the blood serum of Type 2 diabetic patients relative to those of healthy controls. The statistical analyses using multivariate statistical techniques were obvious in the reduction of the experimental variables, and grouping the trace elements in patients into three clusters. The application of PCA revealed a distinct difference in associations of trace elements and their clustering patterns in control and patients group in particular for Mg, Fe, Cu, and Zn that appeared to be the most crucial factors which related with Type 2 diabetes. Therefore, on the basis of this study, the contributors of trace elements content in Type 2 diabetic patients can be determine and specify with correlation relationship and multivariate statistical analysis, which confirm that the alteration of some essential trace metals may play a role in the development of diabetes mellitus. Copyright © 2015 Elsevier GmbH. All rights reserved.

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

Impacts of Rising Health Care Costs on Families with Employment-Based Private Insurance: A National Analysis with State Fixed Effects

PubMed Central

Yu, Hao; Dick, Andrew W

2012-01-01

Background Given the rapid growth of health care costs, some experts were concerned with erosion of employment-based private insurance (EBPI). This empirical analysis aims to quantify the concern. Methods Using the National Health Account, we generated a cost index to represent state-level annual cost growth. We merged it with the 1996–2003 Medical Expenditure Panel Survey. The unit of analysis is the family. We conducted both bivariate and multivariate logistic analyses. Results The bivariate analysis found a significant inverse association between the cost index and the proportion of families receiving an offer of EBPI. The multivariate analysis showed that the cost index was significantly negatively associated with the likelihood of receiving an EBPI offer for the entire sample and for families in the first, second, and third quartiles of income distribution. The cost index was also significantly negatively associated with the proportion of families with EBPI for the entire year for each family member (EBPI-EYEM). The multivariate analysis confirmed significance of the relationship for the entire sample, and for families in the second and third quartiles of income distribution. Among the families with EBPI-EYEM, there was a positive relationship between the cost index and this group's likelihood of having out-of-pocket expenditures exceeding 10 percent of family income. The multivariate analysis confirmed significance of the relationship for the entire group and for families in the second and third quartiles of income distribution. Conclusions Rising health costs reduce EBPI availability and enrollment, and the financial protection provided by it, especially for middle-class families. PMID:22417314

Multivariate temporal pattern analysis applied to the study of rat behavior in the elevated plus maze: methodological and conceptual highlights.

PubMed

Casarrubea, M; Magnusson, M S; Roy, V; Arabo, A; Sorbera, F; Santangelo, A; Faulisi, F; Crescimanno, G

2014-08-30

Aim of this article is to illustrate the application of a multivariate approach known as t-pattern analysis in the study of rat behavior in elevated plus maze. By means of this multivariate approach, significant relationships among behavioral events in the course of time can be described. Both quantitative and t-pattern analyses were utilized to analyze data obtained from fifteen male Wistar rats following a trial 1-trial 2 protocol. In trial 2, in comparison with the initial exposure, mean occurrences of behavioral elements performed in protected zones of the maze showed a significant increase counterbalanced by a significant decrease of mean occurrences of behavioral elements in unprotected zones. Multivariate t-pattern analysis, in trial 1, revealed the presence of 134 t-patterns of different composition. In trial 2, the temporal structure of behavior become more simple, being present only 32 different t-patterns. Behavioral strings and stripes (i.e. graphical representation of each t-pattern onset) of all t-patterns were presented both for trial 1 and trial 2 as well. Finally, percent distributions in the three zones of the maze show a clear-cut increase of t-patterns in closed arm and a significant reduction in the remaining zones. Results show that previous experience deeply modifies the temporal structure of rat behavior in the elevated plus maze. In addition, this article, by highlighting several conceptual, methodological and illustrative aspects on the utilization of t-pattern analysis, could represent a useful background to employ such a refined approach in the study of rat behavior in elevated plus maze. Copyright © 2014 Elsevier B.V. All rights reserved.