Capitation pricing: Adjusting for prior utilization and physician discretion

PubMed Central

Anderson, Gerard F.; Cantor, Joel C.; Steinberg, Earl P.; Holloway, James

1986-01-01

As the number of Medicare beneficiaries receiving care under at-risk capitation arrangements increases, the method for setting payment rates will come under increasing scrutiny. A number of modifications to the current adjusted average per capita cost (AAPCC) methodology have been proposed, including an adjustment for prior utilization. In this article, we propose use of a utilization adjustment that includes only hospitalizations involving low or moderate physician discretion in the decision to hospitalize. This modification avoids discrimination against capitated systems that prevent certain discretionary admissions. The model also explains more of the variance in per capita expenditures than does the current AAPCC. PMID:10312010

Health-based risk adjustment: improving the pharmacy-based cost group model by adding diagnostic cost groups.

PubMed

Prinsze, Femmeke J; van Vliet, René C J A

Since 1991, risk-adjusted premium subsidies have existed in the Dutch social health insurance sector, which covered about two-thirds of the population until 2006. In 2002, pharmacy-based cost groups (PCGs) were included in the demographic risk adjustment model, which improved the goodness-of-fit, as measured by the R2, to 11.5%. The model's R2 reached 22.8% in 2004, when inpatient diagnostic information was added in the form of diagnostic cost groups (DCGs). PCGs and DCGs appear to be complementary in their ability to predict future costs. PCGs particularly improve the R2 for outpatient expenses, whereas DCGs improve the R2 for inpatient expenses. In 2006, this system of risk-adjusted premium subsidies was extended to cover the entire population.

Ethnic-Racial Socialization and Adjustment among Latino College Students: The Mediating Roles of Ethnic Centrality, Public Regard, and Perceived Barriers to Opportunity

ERIC Educational Resources Information Center

Rivas-Drake, Deborah

2011-01-01

Parents' efforts to socialize their children around issues of ethnicity and race have implications for well-being in several life domains, including academic and psychological adjustment. The present study tested a multiple mediator model in which parental ethnic-racial socialization was linked to psychological adjustment through two dimensions of…

The Effect of Adding Comorbidities to Current Centers for Disease Control and Prevention Central-Line-Associated Bloodstream Infection Risk-Adjustment Methodology.

PubMed

Jackson, Sarah S; Leekha, Surbhi; Magder, Laurence S; Pineles, Lisa; Anderson, Deverick J; Trick, William E; Woeltje, Keith F; Kaye, Keith S; Stafford, Kristen; Thom, Kerri; Lowe, Timothy J; Harris, Anthony D

2017-09-01

BACKGROUND Risk adjustment is needed to fairly compare central-line-associated bloodstream infection (CLABSI) rates between hospitals. Until 2017, the Centers for Disease Control and Prevention (CDC) methodology adjusted CLABSI rates only by type of intensive care unit (ICU). The 2017 CDC models also adjust for hospital size and medical school affiliation. We hypothesized that risk adjustment would be improved by including patient demographics and comorbidities from electronically available hospital discharge codes. METHODS Using a cohort design across 22 hospitals, we analyzed data from ICU patients admitted between January 2012 and December 2013. Demographics and International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) discharge codes were obtained for each patient, and CLABSIs were identified by trained infection preventionists. Models adjusting only for ICU type and for ICU type plus patient case mix were built and compared using discrimination and standardized infection ratio (SIR). Hospitals were ranked by SIR for each model to examine and compare the changes in rank. RESULTS Overall, 85,849 ICU patients were analyzed and 162 (0.2%) developed CLABSI. The significant variables added to the ICU model were coagulopathy, paralysis, renal failure, malnutrition, and age. The C statistics were 0.55 (95% CI, 0.51-0.59) for the ICU-type model and 0.64 (95% CI, 0.60-0.69) for the ICU-type plus patient case-mix model. When the hospitals were ranked by adjusted SIRs, 10 hospitals (45%) changed rank when comorbidity was added to the ICU-type model. CONCLUSIONS Our risk-adjustment model for CLABSI using electronically available comorbidities demonstrated better discrimination than did the CDC model. The CDC should strongly consider comorbidity-based risk adjustment to more accurately compare CLABSI rates across hospitals. Infect Control Hosp Epidemiol 2017;38:1019-1024.

Adolescent Sibling Relationship Quality and Adjustment: Sibling Trustworthiness and Modeling, as Factors Directly and Indirectly Influencing These Associations

ERIC Educational Resources Information Center

Gamble, Wendy C.; Yu, Jeong Jin; Kuehn, Emily D.

2011-01-01

The main goal of this study was to examine the direct and moderating effects of trustworthiness and modeling on adolescent siblings' adjustment. Data were collected from 438 families including a mother, a younger sibling in fifth, sixth, or seventh grade (M = 11.6 years), and an older sibling (M = 14.3 years). Respondents completed Web-based…

First-Year Village: Experimenting with an African Model for First-Year Adjustment and Support in South Africa

ERIC Educational Resources Information Center

Speckman, McGlory

2016-01-01

Predicated on the principles of success and contextuality, this chapter shares an African perspective on a first-year adjustment programme, known as First-Year Village, including its potential and challenges in establishing it.

Incorporating Stroke Severity Into Hospital Measures of 30-Day Mortality After Ischemic Stroke Hospitalization.

PubMed

Schwartz, Jennifer; Wang, Yongfei; Qin, Li; Schwamm, Lee H; Fonarow, Gregg C; Cormier, Nicole; Dorsey, Karen; McNamara, Robert L; Suter, Lisa G; Krumholz, Harlan M; Bernheim, Susannah M

2017-11-01

The Centers for Medicare & Medicaid Services publicly reports a hospital-level stroke mortality measure that lacks stroke severity risk adjustment. Our objective was to describe novel measures of stroke mortality suitable for public reporting that incorporate stroke severity into risk adjustment. We linked data from the American Heart Association/American Stroke Association Get With The Guidelines-Stroke registry with Medicare fee-for-service claims data to develop the measures. We used logistic regression for variable selection in risk model development. We developed 3 risk-standardized mortality models for patients with acute ischemic stroke, all of which include the National Institutes of Health Stroke Scale score: one that includes other risk variables derived only from claims data (claims model); one that includes other risk variables derived from claims and clinical variables that could be obtained from electronic health record data (hybrid model); and one that includes other risk variables that could be derived only from electronic health record data (electronic health record model). The cohort used to develop and validate the risk models consisted of 188 975 hospital admissions at 1511 hospitals. The claims, hybrid, and electronic health record risk models included 20, 21, and 9 risk-adjustment variables, respectively; the C statistics were 0.81, 0.82, and 0.79, respectively (as compared with the current publicly reported model C statistic of 0.75); the risk-standardized mortality rates ranged from 10.7% to 19.0%, 10.7% to 19.1%, and 10.8% to 20.3%, respectively; the median risk-standardized mortality rate was 14.5% for all measures; and the odds of mortality for a high-mortality hospital (+1 SD) were 1.51, 1.52, and 1.52 times those for a low-mortality hospital (-1 SD), respectively. We developed 3 quality measures that demonstrate better discrimination than the Centers for Medicare & Medicaid Services' existing stroke mortality measure, adjust for stroke severity, and could be implemented in a variety of settings. © 2017 American Heart Association, Inc.

Three methods to construct predictive models using logistic regression and likelihood ratios to facilitate adjustment for pretest probability give similar results.

PubMed

Chan, Siew Foong; Deeks, Jonathan J; Macaskill, Petra; Irwig, Les

2008-01-01

To compare three predictive models based on logistic regression to estimate adjusted likelihood ratios allowing for interdependency between diagnostic variables (tests). This study was a review of the theoretical basis, assumptions, and limitations of published models; and a statistical extension of methods and application to a case study of the diagnosis of obstructive airways disease based on history and clinical examination. Albert's method includes an offset term to estimate an adjusted likelihood ratio for combinations of tests. Spiegelhalter and Knill-Jones method uses the unadjusted likelihood ratio for each test as a predictor and computes shrinkage factors to allow for interdependence. Knottnerus' method differs from the other methods because it requires sequencing of tests, which limits its application to situations where there are few tests and substantial data. Although parameter estimates differed between the models, predicted "posttest" probabilities were generally similar. Construction of predictive models using logistic regression is preferred to the independence Bayes' approach when it is important to adjust for dependency of tests errors. Methods to estimate adjusted likelihood ratios from predictive models should be considered in preference to a standard logistic regression model to facilitate ease of interpretation and application. Albert's method provides the most straightforward approach.

The Role of the Broader Autism Phenotype and Environmental Stressors in the Adjustment of Siblings of Children with Autism Spectrum Disorders in Taiwan and the United Kingdom.

PubMed

Tsai, Hsiao-Wei Joy; Cebula, Katie; Fletcher-Watson, Sue

2017-08-01

The influence of the broader autism phenotype (BAP) on the adjustment of siblings of children with autism has previously been researched mainly in Western cultures. The present research evaluated a diathesis-stress model of sibling adjustment using a questionnaire study including 80 and 75 mother-typically developing sibling dyads in Taiwan and the United Kingdom (UK). UK siblings reported elevated adjustment difficulties compared to the Taiwanese sample and to normative data. Whilst higher BAP levels were generally associated with greater adjustment difficulties, differences were found across cultures and respondents. Although significant diathesis-stress interactions were found, these were in the opposite direction from those predicted by the model, and differed across cultural settings. Implications for culturally-sensitive sibling support are considered.

Forecasting longitudinal changes in oropharyngeal tumor morphology throughout the course of head and neck radiation therapy

PubMed Central

Yock, Adam D.; Rao, Arvind; Dong, Lei; Beadle, Beth M.; Garden, Adam S.; Kudchadker, Rajat J.; Court, Laurence E.

2014-01-01

Purpose: To create models that forecast longitudinal trends in changing tumor morphology and to evaluate and compare their predictive potential throughout the course of radiation therapy. Methods: Two morphology feature vectors were used to describe 35 gross tumor volumes (GTVs) throughout the course of intensity-modulated radiation therapy for oropharyngeal tumors. The feature vectors comprised the coordinates of the GTV centroids and a description of GTV shape using either interlandmark distances or a spherical harmonic decomposition of these distances. The change in the morphology feature vector observed at 33 time points throughout the course of treatment was described using static, linear, and mean models. Models were adjusted at 0, 1, 2, 3, or 5 different time points (adjustment points) to improve prediction accuracy. The potential of these models to forecast GTV morphology was evaluated using leave-one-out cross-validation, and the accuracy of the models was compared using Wilcoxon signed-rank tests. Results: Adding a single adjustment point to the static model without any adjustment points decreased the median error in forecasting the position of GTV surface landmarks by the largest amount (1.2 mm). Additional adjustment points further decreased the forecast error by about 0.4 mm each. Selection of the linear model decreased the forecast error for both the distance-based and spherical harmonic morphology descriptors (0.2 mm), while the mean model decreased the forecast error for the distance-based descriptor only (0.2 mm). The magnitude and statistical significance of these improvements decreased with each additional adjustment point, and the effect from model selection was not as large as that from adding the initial points. Conclusions: The authors present models that anticipate longitudinal changes in tumor morphology using various models and model adjustment schemes. The accuracy of these models depended on their form, and the utility of these models includes the characterization of patient-specific response with implications for treatment management and research study design. PMID:25086518

Forecasting longitudinal changes in oropharyngeal tumor morphology throughout the course of head and neck radiation therapy

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

Yock, Adam D.; Kudchadker, Rajat J.; Rao, Arvind

2014-08-15

Purpose: To create models that forecast longitudinal trends in changing tumor morphology and to evaluate and compare their predictive potential throughout the course of radiation therapy. Methods: Two morphology feature vectors were used to describe 35 gross tumor volumes (GTVs) throughout the course of intensity-modulated radiation therapy for oropharyngeal tumors. The feature vectors comprised the coordinates of the GTV centroids and a description of GTV shape using either interlandmark distances or a spherical harmonic decomposition of these distances. The change in the morphology feature vector observed at 33 time points throughout the course of treatment was described using static, linear,more » and mean models. Models were adjusted at 0, 1, 2, 3, or 5 different time points (adjustment points) to improve prediction accuracy. The potential of these models to forecast GTV morphology was evaluated using leave-one-out cross-validation, and the accuracy of the models was compared using Wilcoxon signed-rank tests. Results: Adding a single adjustment point to the static model without any adjustment points decreased the median error in forecasting the position of GTV surface landmarks by the largest amount (1.2 mm). Additional adjustment points further decreased the forecast error by about 0.4 mm each. Selection of the linear model decreased the forecast error for both the distance-based and spherical harmonic morphology descriptors (0.2 mm), while the mean model decreased the forecast error for the distance-based descriptor only (0.2 mm). The magnitude and statistical significance of these improvements decreased with each additional adjustment point, and the effect from model selection was not as large as that from adding the initial points. Conclusions: The authors present models that anticipate longitudinal changes in tumor morphology using various models and model adjustment schemes. The accuracy of these models depended on their form, and the utility of these models includes the characterization of patient-specific response with implications for treatment management and research study design.« less

Predicting cost of care using self-reported health status data.

PubMed

Boscardin, Christy K; Gonzales, Ralph; Bradley, Kent L; Raven, Maria C

2015-09-23

We examined whether self-reported employee health status data can improve the performance of administrative data-based models for predicting future high health costs, and develop a predictive model for predicting new high cost individuals. This retrospective cohort study used data from 8,917 Safeway employees self-insured by Safeway during 2008 and 2009. We created models using step-wise multivariable logistic regression starting with health services use data, then socio-demographic data, and finally adding the self-reported health status data to the model. Adding self-reported health data to the baseline model that included only administrative data (health services use and demographic variables; c-statistic = 0.63) increased the model" predictive power (c-statistic = 0.70). Risk factors associated with being a new high cost individual in 2009 were: 1) had one or more ED visits in 2008 (adjusted OR: 1.87, 95 % CI: 1.52, 2.30), 2) had one or more hospitalizations in 2008 (adjusted OR: 1.95, 95 % CI: 1.38, 2.77), 3) being female (adjusted OR: 1.34, 95 % CI: 1.16, 1.55), 4) increasing age (compared with age 18-35, adjusted OR for 36-49 years: 1.28; 95 % CI: 1.03, 1.60; adjusted OR for 50-64 years: 1.92, 95 % CI: 1.55, 2.39; adjusted OR for 65+ years: 3.75, 95 % CI: 2.67, 2.23), 5) the presence of self-reported depression (adjusted OR: 1.53, 95 % CI: 1.29, 1.81), 6) chronic pain (adjusted OR: 2.22, 95 % CI: 1.81, 2.72), 7) diabetes (adjusted OR: 1.73, 95 % CI: 1.35, 2.23), 8) high blood pressure (adjusted OR: 1.42, 95 % CI: 1.21, 1.67), and 9) above average BMI (adjusted OR: 1.20, 95 % CI: 1.04, 1.38). The comparison of the models between the full sample and the sample without theprevious high cost members indicated significant differences in the predictors. This has importantimplications for models using only the health service use (administrative data) given that the past high costis significantly correlated with future high cost and often drive the predictive models. Self-reported health data improved the ability of our model to identify individuals at risk for being high cost beyond what was possible with administrative data alone.

Ion flux through membrane channels--an enhanced algorithm for the Poisson-Nernst-Planck model.

PubMed

Dyrka, Witold; Augousti, Andy T; Kotulska, Malgorzata

2008-09-01

A novel algorithmic scheme for numerical solution of the 3D Poisson-Nernst-Planck model is proposed. The algorithmic improvements are universal and independent of the detailed physical model. They include three major steps: an adjustable gradient-based step value, an adjustable relaxation coefficient, and an optimized segmentation of the modeled space. The enhanced algorithm significantly accelerates the speed of computation and reduces the computational demands. The theoretical model was tested on a regular artificial channel and validated on a real protein channel-alpha-hemolysin, proving its efficiency. (c) 2008 Wiley Periodicals, Inc.

A Review on Methods of Risk Adjustment and their Use in Integrated Healthcare Systems

PubMed Central

Juhnke, Christin; Bethge, Susanne

2016-01-01

Introduction: Effective risk adjustment is an aspect that is more and more given weight on the background of competitive health insurance systems and vital healthcare systems. The objective of this review was to obtain an overview of existing models of risk adjustment as well as on crucial weights in risk adjustment. Moreover, the predictive performance of selected methods in international healthcare systems should be analysed. Theory and methods: A comprehensive, systematic literature review on methods of risk adjustment was conducted in terms of an encompassing, interdisciplinary examination of the related disciplines. Results: In general, several distinctions can be made: in terms of risk horizons, in terms of risk factors or in terms of the combination of indicators included. Within these, another differentiation by three levels seems reasonable: methods based on mortality risks, methods based on morbidity risks as well as those based on information on (self-reported) health status. Conclusions and discussion: After the final examination of different methods of risk adjustment it was shown that the methodology used to adjust risks varies. The models differ greatly in terms of their included morbidity indicators. The findings of this review can be used in the evaluation of integrated healthcare delivery systems and can be integrated into quality- and patient-oriented reimbursement of care providers in the design of healthcare contracts. PMID:28316544

The Role of the Broader Autism Phenotype and Environmental Stressors in the Adjustment of Siblings of Children with Autism Spectrum Disorders in Taiwan and the United Kingdom

ERIC Educational Resources Information Center

Tsai, Hsiao-Wei Joy; Cebula, Katie; Fletcher-Watson, Sue

2017-01-01

The influence of the broader autism phenotype (BAP) on the adjustment of siblings of children with autism has previously been researched mainly in Western cultures. The present research evaluated a diathesis-stress model of sibling adjustment using a questionnaire study including 80 and 75 mother-typically developing sibling dyads in Taiwan and…

Adjustment patterns of the Arab internal refugees in Israel.

PubMed

Al-haj, M

1986-09-01

This analysis is pursued in the framework of an interrelated multidimensional model which includes 5 main components: 1) dimensions of adjustment, 2) range of adjustment, 3) levels of adjustment, 4) typology of aggregate adjustment, and 5) indicators of mobility and variation in the refugee adjustment. Arab internal refugees in Israel, including their characteristics and patterns of adjustment in the host communities as well as in Israeli society, are studied. Social, psychological, and socioeconomic adjustments are separated out and show the importance of the linkage between adjustment patterns at both the communal and the societal levels. The findings indicate that processes of adjustment at the communal and the societal levels are not necessarily conjunctive and symmetric. At the societal level, socioeconomic adjustment occurs relatively more rapidly than social adjustment. At the communal level, inter-marriage with locals lags behind friendship relationships and mutual visits. Psychological adjustment rates in between these 2. Cultural and linguistic compatibility with the host community are crucial positive factors for refugee adjustment. Cultural, linguistic, and national compatibility with the host community may have paradoxically indirect negative effects on the refugee psychological adjustment. High background compatibility generates high expectations among the refugees, which may be easily transferred into alienation, when faced with a different situation than expected; the greater the gap between the expected and the actual, the more the alienation.

A Method of Dynamic Extended Reactive Power Optimization in Distribution Network Containing Photovoltaic-Storage System

NASA Astrophysics Data System (ADS)

Wang, Wu; Huang, Wei; Zhang, Yongjun

2018-03-01

The grid-integration of Photovoltaic-Storage System brings some undefined factors to the network. In order to make full use of the adjusting ability of Photovoltaic-Storage System (PSS), this paper puts forward a reactive power optimization model, which are used to construct the objective function based on power loss and the device adjusting cost, including energy storage adjusting cost. By using Cataclysmic Genetic Algorithm to solve this optimization problem, and comparing with other optimization method, the result proved that: the method of dynamic extended reactive power optimization this article puts forward, can enhance the effect of reactive power optimization, including reducing power loss and device adjusting cost, meanwhile, it gives consideration to the safety of voltage.

Developing Statistical Models to Assess Transplant Outcomes Using National Registries: The Process in the United States.

PubMed

Snyder, Jon J; Salkowski, Nicholas; Kim, S Joseph; Zaun, David; Xiong, Hui; Israni, Ajay K; Kasiske, Bertram L

2016-02-01

Created by the US National Organ Transplant Act in 1984, the Scientific Registry of Transplant Recipients (SRTR) is obligated to publicly report data on transplant program and organ procurement organization performance in the United States. These reports include risk-adjusted assessments of graft and patient survival, and programs performing worse or better than expected are identified. The SRTR currently maintains 43 risk adjustment models for assessing posttransplant patient and graft survival and, in collaboration with the SRTR Technical Advisory Committee, has developed and implemented a new systematic process for model evaluation and revision. Patient cohorts for the risk adjustment models are identified, and single-organ and multiorgan transplants are defined, then each risk adjustment model is developed following a prespecified set of steps. Model performance is assessed, the model is refit to a more recent cohort before each evaluation cycle, and then it is applied to the evaluation cohort. The field of solid organ transplantation is unique in the breadth of the standardized data that are collected. These data allow for quality assessment across all transplant providers in the United States. A standardized process of risk model development using data from national registries may enhance the field.

Development and Evaluation of an Automated Machine Learning Algorithm for In-Hospital Mortality Risk Adjustment Among Critical Care Patients.

PubMed

Delahanty, Ryan J; Kaufman, David; Jones, Spencer S

2018-06-01

Risk adjustment algorithms for ICU mortality are necessary for measuring and improving ICU performance. Existing risk adjustment algorithms are not widely adopted. Key barriers to adoption include licensing and implementation costs as well as labor costs associated with human-intensive data collection. Widespread adoption of electronic health records makes automated risk adjustment feasible. Using modern machine learning methods and open source tools, we developed and evaluated a retrospective risk adjustment algorithm for in-hospital mortality among ICU patients. The Risk of Inpatient Death score can be fully automated and is reliant upon data elements that are generated in the course of usual hospital processes. One hundred thirty-one ICUs in 53 hospitals operated by Tenet Healthcare. A cohort of 237,173 ICU patients discharged between January 2014 and December 2016. The data were randomly split into training (36 hospitals), and validation (17 hospitals) data sets. Feature selection and model training were carried out using the training set while the discrimination, calibration, and accuracy of the model were assessed in the validation data set. Model discrimination was evaluated based on the area under receiver operating characteristic curve; accuracy and calibration were assessed via adjusted Brier scores and visual analysis of calibration curves. Seventeen features, including a mix of clinical and administrative data elements, were retained in the final model. The Risk of Inpatient Death score demonstrated excellent discrimination (area under receiver operating characteristic curve = 0.94) and calibration (adjusted Brier score = 52.8%) in the validation dataset; these results compare favorably to the published performance statistics for the most commonly used mortality risk adjustment algorithms. Low adoption of ICU mortality risk adjustment algorithms impedes progress toward increasing the value of the healthcare delivered in ICUs. The Risk of Inpatient Death score has many attractive attributes that address the key barriers to adoption of ICU risk adjustment algorithms and performs comparably to existing human-intensive algorithms. Automated risk adjustment algorithms have the potential to obviate known barriers to adoption such as cost-prohibitive licensing fees and significant direct labor costs. Further evaluation is needed to ensure that the level of performance observed in this study could be achieved at independent sites.

Bidirectional Influences of Violence Exposure and Adjustment in Early Adolescence: Externalizing Behaviors and School Connectedness

ERIC Educational Resources Information Center

Mrug, Sylvie; Windle, Michael

2009-01-01

This study utilized cross-lagged longitudinal models to examine prospective, bidirectional relationships between witnessing violence and victimization and three adjustment variables--delinquency, conduct problems, and school connectedness. Participants included 603 early adolescent boys and girls (78% African American, 20% Caucasian). Witnessing…

State infant mortality: an ecologic study to determine modifiable risks and adjusted infant mortality rates.

PubMed

Paul, David A; Mackley, Amy; Locke, Robert G; Stefano, John L; Kroelinger, Charlan

2009-05-01

To determine factors contributing to state infant mortality rates (IMR) and develop an adjusted IMR in the United States for 2001 and 2002. Ecologic study of factors contributing to state IMR. State IMR for 2001 and 2002 were obtained from the United States linked death and birth certificate data from the National Center for Health Statistics. Factors investigated using multivariable linear regression included state racial demographics, ethnicity, state population, median income, education, teen birth rate, proportion of obesity, smoking during pregnancy, diabetes, hypertension, cesarean delivery, prenatal care, health insurance, self-report of mental illness, and number of in-vitro fertilization procedures. Final risk adjusted IMR's were standardized and states were compared with the United States adjusted rates. Models for IMR in individual states in 2001 (r2 = 0.66, P < 0.01) and 2002 (r2 = 0.81, P < 0.01) were tested. African-American race, teen birth rate, and smoking during pregnancy remained independently associated with state infant mortality rates for 2001 and 2002. Ninety five percent confidence intervals (CI) were calculated around the regression lines to model the expected IMR. After adjustment, some states maintained a consistent IMR; for instance, Vermont and New Hampshire remained low, while Delaware and Louisiana remained high. However, other states such as Mississippi, which have traditionally high infant mortality rates, remained within the expected 95% CI for IMR after adjustment indicating confounding affected the initial unadjusted rates. Non-modifiable demographic variables, including the percentage of non-Hispanic African-American and Hispanic populations of the state are major factors contributing to individual variation in state IMR. Race and ethnicity may confound or modify the IMR in states that shifted inside or outside the 95% CI following adjustment. Other factors including smoking during pregnancy and teen birth rate, which are potentially modifiable, significantly contributed to differences in state IMR. State risk adjusted IMR indicate that other factors impact infant mortality after adjustment by race/ethnicity and other risk factors.

Relation of Pericardial Fat, Intrathoracic Fat, and Abdominal Visceral Fat with Incident Atrial Fibrillation (From the Framingham Heart Study)

PubMed Central

Lee, Jane J.; Yin, Xiaoyan; Hoffmann, Udo; Fox, Caroline S.; Benjamin, Emelia J.

2016-01-01

Obesity is associated with increased risk of developing atrial fibrillation (AF). Different fat depots may have differential associations with cardiac pathology. We examined the longitudinal associations between pericardial, intrathoracic, and visceral fat with incident AF. We studied Framingham Heart Study Offspring and Third Generation Cohorts who participated in the multi-detector computed tomography sub-study examination 1. We constructed multivariable-adjusted Cox proportional hazard models for risk of incident AF. Body mass index (BMI) was included in the multivariable-adjusted model as a secondary adjustment. We included 2,135 participants (53.3% women; mean age 58.8 years). During a median follow-up of 9.7 years, we identified 162 cases of incident AF. Across the increasing tertiles of pericardial fat volume, age- and sex-adjusted incident AF rate per 1000 person-years of follow-up were 8.4, 7.5, and 10.2. Based on an age- and sex-adjusted model, greater pericardial fat [hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.03-1.34] and intrathoracic fat (HR 1.24, 95% CI 1.06-1.45) were associated with increased risk of incident AF. The HRs (95% CI) for incident AF were 1.13 (0.99-1.30) for pericardial fat, 1.19 (1.01-1.40) for intrathoracic fat, and 1.09 (0.93-1.28) for abdominal visceral fat after multivariable adjustment. After additional adjustment of BMI, none of the associations remained significant (all p>0.05). Our findings suggest that cardiac ectopic fat depots may share common risk factors with AF, which may have led to a lack of independence in the association between pericardial fat with incident AF. PMID:27666172

Sample Size and Statistical Conclusions from Tests of Fit to the Rasch Model According to the Rasch Unidimensional Measurement Model (Rumm) Program in Health Outcome Measurement.

PubMed

Hagell, Peter; Westergren, Albert

Sample size is a major factor in statistical null hypothesis testing, which is the basis for many approaches to testing Rasch model fit. Few sample size recommendations for testing fit to the Rasch model concern the Rasch Unidimensional Measurement Models (RUMM) software, which features chi-square and ANOVA/F-ratio based fit statistics, including Bonferroni and algebraic sample size adjustments. This paper explores the occurrence of Type I errors with RUMM fit statistics, and the effects of algebraic sample size adjustments. Data with simulated Rasch model fitting 25-item dichotomous scales and sample sizes ranging from N = 50 to N = 2500 were analysed with and without algebraically adjusted sample sizes. Results suggest the occurrence of Type I errors with N less then or equal to 500, and that Bonferroni correction as well as downward algebraic sample size adjustment are useful to avoid such errors, whereas upward adjustment of smaller samples falsely signal misfit. Our observations suggest that sample sizes around N = 250 to N = 500 may provide a good balance for the statistical interpretation of the RUMM fit statistics studied here with respect to Type I errors and under the assumption of Rasch model fit within the examined frame of reference (i.e., about 25 item parameters well targeted to the sample).

The predictive consequences of parameterization

NASA Astrophysics Data System (ADS)

White, J.; Hughes, J. D.; Doherty, J. E.

2013-12-01

In numerical groundwater modeling, parameterization is the process of selecting the aspects of a computer model that will be allowed to vary during history matching. This selection process is dependent on professional judgment and is, therefore, inherently subjective. Ideally, a robust parameterization should be commensurate with the spatial and temporal resolution of the model and should include all uncertain aspects of the model. Limited computing resources typically require reducing the number of adjustable parameters so that only a subset of the uncertain model aspects are treated as estimable parameters; the remaining aspects are treated as fixed parameters during history matching. We use linear subspace theory to develop expressions for the predictive error incurred by fixing parameters. The predictive error is comprised of two terms. The first term arises directly from the sensitivity of a prediction to fixed parameters. The second term arises from prediction-sensitive adjustable parameters that are forced to compensate for fixed parameters during history matching. The compensation is accompanied by inappropriate adjustment of otherwise uninformed, null-space parameter components. Unwarranted adjustment of null-space components away from prior maximum likelihood values may produce bias if a prediction is sensitive to those components. The potential for subjective parameterization choices to corrupt predictions is examined using a synthetic model. Several strategies are evaluated, including use of piecewise constant zones, use of pilot points with Tikhonov regularization and use of the Karhunen-Loeve transformation. The best choice of parameterization (as defined by minimum error variance) is strongly dependent on the types of predictions to be made by the model.

Relationship between dietary pattern and cognitive function in elderly patients with type 2 diabetes mellitus.

PubMed

Enomoto, Mari; Yoshii, Hidenori; Mita, Tomoya; Sanke, Haruna; Yokota, Ayako; Yamashiro, Keiko; Inagaki, Noriko; Gosho, Masahiko; Ohmura, Chie; Kudo, Kayo; Watada, Hirotaka; Onuma, Tomio

2015-08-01

To analyse the relationships between dietary patterns and cognitive function in elderly patients with type 2 diabetes mellitus (T2DM). Patients with T2DM completed a 3-day dietary record and Mini-mental State Examination (MMSE). Dietary patterns were identified by factor analysis. The study included 73 patients and identified five dietary patterns, one of which was characterized by high loading for vegetables and fish. A higher consumption of vegetables and fish was significantly associated with improved MMSE score (unadjusted model, model adjusted for age and sex, and model adjusted for age, sex, education, diabetic nephropathy and alcohol consumption), and decreased prevalence of suspected mild dementia (unadjusted model, model adjusted for age and sex). A high score in the vegetables and fish dietary pattern was associated with high MMSE score and low prevalence of suspected mild dementia in elderly patients with T2DM. © The Author(s) 2015.

Stromal-epithelial dynamics in response to fractionated radiotherapy

NASA Astrophysics Data System (ADS)

Rong, Panying

The speech of individuals with velopharyngeal incompetency (VPI) is characterized by hypernasality, a speech quality related to excessive emission of acoustic energy through the nose, as caused by failure of velopharyngeal closure. As an attempt to reduce hypernasality and, in turn, improve the quality of VPI-related hypernasal speech, this study is dedicated to developing an approach that uses speech-dependent articulatory adjustments to reduce hypernasality caused by excessive velopharyngeal opening. A preliminary study has been done to derive such articulatory adjustments for hypernasal /i/ vowels based on the simulation of an articulatorymodel (Speech Processing and Synthesis Toolboxes, Childers (2000)). Both nasal /i/ vowels with and without articulatory adjustments were synthesized by the model. Spectral analysis found that nasal acoustic features were attenuated and oral formant structures were restored after articulatory adjustments. In addition, comparisons of perceptual ratings of nasality between the two types of nasal vowels showed the articulatory adjustments generated by the model significantly reduced the perception of nasality for nasal /i/ vowels. Such articulatory adjustments for nasal /i/ have two patterns: 1) a consistent adjustment pattern, which corresponds an expansion at the velopharynx, and 2) some speech-dependent fine-tuning adjustment patterns, including adjustments in the lip area and the upper pharynx. The long-term goal of this study is to apply this approach of articulatory adjustment as a therapeutic tool in clinical speech treatment to detect and correct the maladaptive articulatory behaviors developed spontaneously by speakers with VPI on individual bases. This study constructed a speaker-adaptive articulatory model on the basis of the framework of Childers's vocal tract model to simulate articulatory adjustments aiming at compensating for the acoustic outcome caused by velopharyngeal opening and reducing nasality. To construct such a speaker-adaptive articulatory model, (1) an articulatory-acoustic-aerodynamic database was recorded using the articulography and aerodynamic instruments to provide point-wise articulatory data to be fitted into the framework of Childers's standard vocal tract model; (2) the length and transverse dimension of the vocal tract were adjusted to fit individual speaker by minimizing the acoustic discrepancy between the model simulation and the target derived from acoustic signal in the database using the simulated annealing algorithm; (3) the articulatory space of the model was adjusted to fit individual articulatory features by adapting the movement ranges of all articulators. With the speaker-adaptive articulatory model, the articulatory configurations of the oral and nasal vowels in the database were simulated and synthesized. Given the acoustic targets derived from the oral vowels in the database, speech-dependent articulatory adjustments were simulated to compensate for the acoustic outcome caused by VPO. The resultant articulatory configurations corresponds to nasal vowels with articulatory adjustment, which were synthesized to serve as the perceptual stimuli for a listening task of nasality rating. The oral and nasal vowels synthesized based on the oral and nasal vowel targets in the database also served as the perceptual stimuli. The results suggest both acoustic and perceptual effects of the mode-generated articulatory adjustment on the nasal vowels /a/, /i/ and /u/. In terms of acoustics, the articulatory adjustment (1) restores the altered formant structures due to nasal coupling, including shifted formant frequency, attenuated formant intensity and expanded formant bandwidth and (2) attenuates the peaks and zeros caused by nasal resonances. Perceptually, the articulatory adjustment generated by the speaker-adaptive model significantly reduces the perceived nasality for all three vowels (/a/, /i/, /u/). The acoustic and perceptual effects of articulatory adjustment suggest achievement of the acoustic goal of compensating for the acoustic discrepancy caused by VPO and the auditory goal of reducing the perception of nasality. Such a finding is consistent with motor equivalence (Hughes and Abbs, 1976; Maeda, 1990), which enables inter-articulator coordination to compensate for the deviation from the acoustic/auditory goal caused by the shifted position of an articulator. The articulatory adjustment responsible for the acoustic and perceptual effects as described above was decomposed into a set of empirical orthogonal modes (Story and Titze, 1998). Both gross articulatory patterns and fine-tuning adjustments were found in the principal orthogonal modes, which lead to the acoustic compensation and reduction of nasality. For /a/ and /i/, a direct relationship was found among the acoustic features, nasality, and articulatory adjustment patterns. Specifically, the articulatory adjustments indicated by the principal orthogonal modes of the adjusted nasal /a/ and /i/ were directly correlated with the attenuation of the acoustic cues of nasality (i.e., shifting of F1 and F2 frequencies) and the reduction of nasality rating. For /u/, such a direct relationship among the acoustic features, nasality and articulatory adjustment was not as prominent, suggesting the possibility of additional acoustic correlates of nasality other than F1 and F2. The findings of this study demonstrate the possibility of using articulatory adjustment to reduce the perception of nasality through model simulation. A speaker-adaptive articulatory model is able to simulate individual-based articulatory adjustment strategies that can be applied in clinical settings to serve as the articulatory targets for correction of the maladaptive articulatory behaviors developed spontaneously by speakers with hypernasal speech. Such a speaker-adaptive articulatory model provides an intuitive way of articulatory learning and self-training for speakers with VPI to learn appropriate articulatory strategies through model-speaker interaction.

The alarming problems of confounding equivalence using logistic regression models in the perspective of causal diagrams.

PubMed

Yu, Yuanyuan; Li, Hongkai; Sun, Xiaoru; Su, Ping; Wang, Tingting; Liu, Yi; Yuan, Zhongshang; Liu, Yanxun; Xue, Fuzhong

2017-12-28

Confounders can produce spurious associations between exposure and outcome in observational studies. For majority of epidemiologists, adjusting for confounders using logistic regression model is their habitual method, though it has some problems in accuracy and precision. It is, therefore, important to highlight the problems of logistic regression and search the alternative method. Four causal diagram models were defined to summarize confounding equivalence. Both theoretical proofs and simulation studies were performed to verify whether conditioning on different confounding equivalence sets had the same bias-reducing potential and then to select the optimum adjusting strategy, in which logistic regression model and inverse probability weighting based marginal structural model (IPW-based-MSM) were compared. The "do-calculus" was used to calculate the true causal effect of exposure on outcome, then the bias and standard error were used to evaluate the performances of different strategies. Adjusting for different sets of confounding equivalence, as judged by identical Markov boundaries, produced different bias-reducing potential in the logistic regression model. For the sets satisfied G-admissibility, adjusting for the set including all the confounders reduced the equivalent bias to the one containing the parent nodes of the outcome, while the bias after adjusting for the parent nodes of exposure was not equivalent to them. In addition, all causal effect estimations through logistic regression were biased, although the estimation after adjusting for the parent nodes of exposure was nearest to the true causal effect. However, conditioning on different confounding equivalence sets had the same bias-reducing potential under IPW-based-MSM. Compared with logistic regression, the IPW-based-MSM could obtain unbiased causal effect estimation when the adjusted confounders satisfied G-admissibility and the optimal strategy was to adjust for the parent nodes of outcome, which obtained the highest precision. All adjustment strategies through logistic regression were biased for causal effect estimation, while IPW-based-MSM could always obtain unbiased estimation when the adjusted set satisfied G-admissibility. Thus, IPW-based-MSM was recommended to adjust for confounders set.

Development of bovine serum albumin-water partition coefficients predictive models for ionogenic organic chemicals based on chemical form adjusted descriptors.

PubMed

Ding, Feng; Yang, Xianhai; Chen, Guosong; Liu, Jining; Shi, Lili; Chen, Jingwen

2017-10-01

The partition coefficients between bovine serum albumin (BSA) and water (K BSA/w ) for ionogenic organic chemicals (IOCs) were different greatly from those of neutral organic chemicals (NOCs). For NOCs, several excellent models were developed to predict their logK BSA/w . However, it was found that the conventional descriptors are inappropriate for modeling logK BSA/w of IOCs. Thus, alternative approaches are urgently needed to develop predictive models for K BSA/w of IOCs. In this study, molecular descriptors that can be used to characterize the ionization effects (e.g. chemical form adjusted descriptors) were calculated and used to develop predictive models for logK BSA/w of IOCs. The models developed had high goodness-of-fit, robustness, and predictive ability. The predictor variables selected to construct the models included the chemical form adjusted averages of the negative potentials on the molecular surface (V s-adj - ), the chemical form adjusted molecular dipole moment (dipolemoment adj ), the logarithm of the n-octanol/water distribution coefficient (logD). As these molecular descriptors can be calculated from their molecular structures directly, the developed model can be easily used to fill the logK BSA/w data gap for other IOCs within the applicability domain. Furthermore, the chemical form adjusted descriptors calculated in this study also could be used to construct predictive models on other endpoints of IOCs. Copyright © 2017 Elsevier Inc. All rights reserved.

Fasting Glucose, Obesity, and Coronary Artery Calcification in Community-Based People Without Diabetes

PubMed Central

Rutter, Martin K.; Massaro, Joseph M.; Hoffmann, Udo; O’Donnell, Christopher J.; Fox, Caroline S.

2012-01-01

OBJECTIVE Our objective was to assess whether impaired fasting glucose (IFG) and obesity are independently related to coronary artery calcification (CAC) in a community-based population. RESEARCH DESIGN AND METHODS We assessed CAC using multidetector computed tomography in 3,054 Framingham Heart Study participants (mean [SD] age was 50 [10] years, 49% were women, 29% had IFG, and 25% were obese) free from known vascular disease or diabetes. We tested the hypothesis that IFG (5.6–6.9 mmol/L) and obesity (BMI ≥30 kg/m2) were independently associated with high CAC (>90th percentile for age and sex) after adjusting for hypertension, lipids, smoking, and medication. RESULTS High CAC was significantly related to IFG in an age- and sex-adjusted model (odds ratio 1.4 [95% CI 1.1–1.7], P = 0.002; referent: normal fasting glucose) and after further adjustment for obesity (1.3 [1.0–1.6], P = 0.045). However, IFG was not associated with high CAC in multivariable-adjusted models before (1.2 [0.9–1.4], P = 0.20) or after adjustment for obesity. Obesity was associated with high CAC in age- and sex-adjusted models (1.6 [1.3–2.0], P < 0.001) and in multivariable models that included IFG (1.4 [1.1–1.7], P = 0.005). Multivariable-adjusted spline regression models suggested nonlinear relationships linking high CAC with BMI (J-shaped), waist circumference (J-shaped), and fasting glucose. CONCLUSIONS In this community-based cohort, CAC was associated with obesity, but not IFG, after adjusting for important confounders. With the increasing worldwide prevalence of obesity and nondiabetic hyperglycemia, these data underscore the importance of obesity in the pathogenesis of CAC. PMID:22773705

Fasting glucose, obesity, and coronary artery calcification in community-based people without diabetes.

PubMed

Rutter, Martin K; Massaro, Joseph M; Hoffmann, Udo; O'Donnell, Christopher J; Fox, Caroline S

2012-09-01

Our objective was to assess whether impaired fasting glucose (IFG) and obesity are independently related to coronary artery calcification (CAC) in a community-based population. We assessed CAC using multidetector computed tomography in 3,054 Framingham Heart Study participants (mean [SD] age was 50 [10] years, 49% were women, 29% had IFG, and 25% were obese) free from known vascular disease or diabetes. We tested the hypothesis that IFG (5.6-6.9 mmol/L) and obesity (BMI ≥30 kg/m(2)) were independently associated with high CAC (>90th percentile for age and sex) after adjusting for hypertension, lipids, smoking, and medication. High CAC was significantly related to IFG in an age- and sex-adjusted model (odds ratio 1.4 [95% CI 1.1-1.7], P = 0.002; referent: normal fasting glucose) and after further adjustment for obesity (1.3 [1.0-1.6], P = 0.045). However, IFG was not associated with high CAC in multivariable-adjusted models before (1.2 [0.9-1.4], P = 0.20) or after adjustment for obesity. Obesity was associated with high CAC in age- and sex-adjusted models (1.6 [1.3-2.0], P < 0.001) and in multivariable models that included IFG (1.4 [1.1-1.7], P = 0.005). Multivariable-adjusted spline regression models suggested nonlinear relationships linking high CAC with BMI (J-shaped), waist circumference (J-shaped), and fasting glucose. In this community-based cohort, CAC was associated with obesity, but not IFG, after adjusting for important confounders. With the increasing worldwide prevalence of obesity and nondiabetic hyperglycemia, these data underscore the importance of obesity in the pathogenesis of CAC.

SIM_ADJUST -- A computer code that adjusts simulated equivalents for observations or predictions

USGS Publications Warehouse

Poeter, Eileen P.; Hill, Mary C.

2008-01-01

This report documents the SIM_ADJUST computer code. SIM_ADJUST surmounts an obstacle that is sometimes encountered when using universal model analysis computer codes such as UCODE_2005 (Poeter and others, 2005), PEST (Doherty, 2004), and OSTRICH (Matott, 2005; Fredrick and others (2007). These codes often read simulated equivalents from a list in a file produced by a process model such as MODFLOW that represents a system of interest. At times values needed by the universal code are missing or assigned default values because the process model could not produce a useful solution. SIM_ADJUST can be used to (1) read a file that lists expected observation or prediction names and possible alternatives for the simulated values; (2) read a file produced by a process model that contains space or tab delimited columns, including a column of simulated values and a column of related observation or prediction names; (3) identify observations or predictions that have been omitted or assigned a default value by the process model; and (4) produce an adjusted file that contains a column of simulated values and a column of associated observation or prediction names. The user may provide alternatives that are constant values or that are alternative simulated values. The user may also provide a sequence of alternatives. For example, the heads from a series of cells may be specified to ensure that a meaningful value is available to compare with an observation located in a cell that may become dry. SIM_ADJUST is constructed using modules from the JUPITER API, and is intended for use on any computer operating system. SIM_ADJUST consists of algorithms programmed in Fortran90, which efficiently performs numerical calculations.

Estimating restricted mean treatment effects with stacked survival models

PubMed Central

Wey, Andrew; Vock, David M.; Connett, John; Rudser, Kyle

2016-01-01

The difference in restricted mean survival times between two groups is a clinically relevant summary measure. With observational data, there may be imbalances in confounding variables between the two groups. One approach to account for such imbalances is estimating a covariate-adjusted restricted mean difference by modeling the covariate-adjusted survival distribution, and then marginalizing over the covariate distribution. Since the estimator for the restricted mean difference is defined by the estimator for the covariate-adjusted survival distribution, it is natural to expect that a better estimator of the covariate-adjusted survival distribution is associated with a better estimator of the restricted mean difference. We therefore propose estimating restricted mean differences with stacked survival models. Stacked survival models estimate a weighted average of several survival models by minimizing predicted error. By including a range of parametric, semi-parametric, and non-parametric models, stacked survival models can robustly estimate a covariate-adjusted survival distribution and, therefore, the restricted mean treatment effect in a wide range of scenarios. We demonstrate through a simulation study that better performance of the covariate-adjusted survival distribution often leads to better mean-squared error of the restricted mean difference although there are notable exceptions. In addition, we demonstrate that the proposed estimator can perform nearly as well as Cox regression when the proportional hazards assumption is satisfied and significantly better when proportional hazards is violated. Finally, the proposed estimator is illustrated with data from the United Network for Organ Sharing to evaluate post-lung transplant survival between large and small-volume centers. PMID:26934835

Case-Mix Adjusting Performance Measures in a Veteran Population: Pharmacy- and Diagnosis-Based Approaches

PubMed Central

Liu, Chuan-Fen; Sales, Anne E; Sharp, Nancy D; Fishman, Paul; Sloan, Kevin L; Todd-Stenberg, Jeff; Nichol, W Paul; Rosen, Amy K; Loveland, Susan

2003-01-01

Objective To compare the rankings for health care utilization performance measures at the facility level in a Veterans Health Administration (VHA) health care delivery network using pharmacy- and diagnosis-based case-mix adjustment measures. Data Sources/Study Setting The study included veterans who used inpatient or outpatient services in Veterans Integrated Service Network (VISN) 20 during fiscal year 1998 (October 1997 to September 1998; N=126,076). Utilization and pharmacy data were extracted from VHA national databases and the VISN 20 data warehouse. Study Design We estimated concurrent regression models using pharmacy or diagnosis information in the base year (FY1998) to predict health service utilization in the same year. Utilization measures included bed days of care for inpatient care and provider visits for outpatient care. Principal Findings Rankings of predicted utilization measures across facilities vary by case-mix adjustment measure. There is greater consistency within the diagnosis-based models than between the diagnosis- and pharmacy-based models. The eight facilities were ranked differently by the diagnosis- and pharmacy-based models. Conclusions Choice of case-mix adjustment measure affects rankings of facilities on performance measures, raising concerns about the validity of profiling practices. Differences in rankings may reflect differences in comparability of data capture across facilities between pharmacy and diagnosis data sources, and unstable estimates due to small numbers of patients in a facility. PMID:14596393

Modeled Urea Distribution Volume and Mortality in the HEMO Study

PubMed Central

Greene, Tom; Depner, Thomas A.; Levin, Nathan W.; Chertow, Glenn M.

2011-01-01

Summary Background and objectives In the Hemodialysis (HEMO) Study, observed small decreases in achieved equilibrated Kt/Vurea were noncausally associated with markedly increased mortality. Here we examine the association of mortality with modeled volume (Vm), the denominator of equilibrated Kt/Vurea. Design, setting, participants, & measurements Parameters derived from modeled urea kinetics (including Vm) and blood pressure (BP) were obtained monthly in 1846 patients. Case mix–adjusted time-dependent Cox regressions were used to relate the relative mortality hazard at each time point to Vm and to the change in Vm over the preceding 6 months. Mixed effects models were used to relate Vm to changes in intradialytic systolic BP and to other factors at each follow-up visit. Results Mortality was associated with Vm and change in Vm over the preceding 6 months. The association between change in Vm and mortality was independent of vascular access complications. In contrast, mortality was inversely associated with V calculated from anthropometric measurements (Vant). In case mix–adjusted analysis using Vm as a time-dependent covariate, the association of mortality with Vm strengthened after statistical adjustment for Vant. After adjustment for Vant, higher Vm was associated with slightly smaller reductions in intradialytic systolic BP and with risk factors for mortality including recent hospitalization and reductions in serum albumin concentration and body weight. Conclusions An increase in Vm is a marker for illness and mortality risk in hemodialysis patients. PMID:21511841

Just Another Club? The Distinctiveness of the Relation between Religious Service Attendance and Adolescent Psychosocial Adjustment

ERIC Educational Resources Information Center

Good, Marie; Willoughby, Teena; Fritjers, Jan

2009-01-01

This study used hierarchical linear modeling to compare longitudinal patterns of adolescent religious service attendance and club attendance, and to contrast the longitudinal relations between adolescent adjustment and religious service versus club attendance. Participants included 1050 students (47% girls) encompassing a school district in…

Parenting and Adolescent Self-Regulation Mediate between Family Socioeconomic Status and Adolescent Adjustment

ERIC Educational Resources Information Center

Farley, Julee P.; Kim-Spoon, Jungmeen

2017-01-01

Using two waves of longitudinal data, we utilized the family stress model of economic hardship to test whether family socioeconomic status is related to adolescent adjustment (substance use and academic achievement) through parental knowledge and adolescent self-regulation (behavioral self-control and delay discounting). Participants included 220…

Paternal age at childbirth and eating disorders in offspring.

PubMed

Javaras, K N; Rickert, M E; Thornton, L M; Peat, C M; Baker, J H; Birgegård, A; Norring, C; Landén, M; Almqvist, C; Larsson, H; Lichtenstein, P; Bulik, C M; D'Onofrio, B M

2017-02-01

Advanced paternal age at childbirth is associated with psychiatric disorders in offspring, including schizophrenia, bipolar disorder and autism. However, few studies have investigated paternal age's relationship with eating disorders in offspring. In a large, population-based cohort, we examined the association between paternal age and offspring eating disorders, and whether that association remains after adjustment for potential confounders (e.g. parental education level) that may be related to late/early selection into fatherhood and to eating disorder incidence. Data for 2 276 809 individuals born in Sweden 1979-2001 were extracted from Swedish population and healthcare registers. The authors used Cox proportional hazards models to examine the effect of paternal age on the first incidence of healthcare-recorded anorexia nervosa (AN) and all eating disorders (AED) occurring 1987-2009. Models were adjusted for sex, birth order, maternal age at childbirth, and maternal and paternal covariates including country of birth, highest education level, and lifetime psychiatric and criminal history. Even after adjustment for covariates including maternal age, advanced paternal age was associated with increased risk, and younger paternal age with decreased risk, of AN and AED. For example, the fully adjusted hazard ratio for the 45+ years (v. the 25-29 years) paternal age category was 1.32 [95% confidence interval (CI) 1.14-1.53] for AN and 1.26 (95% CI 1.13-1.40) for AED. In this large, population-based cohort, paternal age at childbirth was positively associated with eating disorders in offspring, even after adjustment for potential confounders. Future research should further explore potential explanations for the association, including de novo mutations in the paternal germline.

[Interpersonal motivation in a First Year Experience class influences freshmen's university adjustment].

PubMed

Nakayama, Rumiko; Nakanishi, Yoshifumi; Nagahama, Fumiyo; Nakajima, Makoto

2015-06-01

The present study examined the influence of interpersonal motivation on university adjustment in freshman students enrolled in a First Year Experience (FYE) class. An interpersonal motivation scale and a university adjustment (interpersonal adjustment and academic adjustment) scale were administered twice to 116 FYE students; data from the 88 students who completed both surveys were analyzed. Results from structural equation modeling indicated a causal relationship between interpersonal, motivation and university adjustment: interpersonal adjustment served as a mediator between academic adjustment and interpersonal motivation, the latter of which was assessed using the internalized motivation subscale of the Interpersonal Motivation Scale as well as the Relative Autonomy Index, which measures the autonomy in students' interpersonal attitudes. Thus, revising the FYE class curriculum to include approaches to lowering students' feelings of obligation and/or anxiety in their interpersonal interactions might improve their adjustment to university.

Predictors and Neuropsychiatric Profile of Nucleus Basalis of Meynert Degeneration in Parkinson Disease

DTIC Science & Technology

2017-10-01

baseline were available for 228 PD subjects. In a logistic regression model adjusted for age and sex , Ch4 density was associated with lower risk of...events, there were no significant differences in age or sex (p>0.05). PD subjects with 2 or more psychotic events had significantly lower baseline Ch4...Aim 1 and 2 include use of linear regression models to adjust for age, sex , and other significant covariates. Aim 3 is a cross-sectional controlled

Analysis of Longitudinal Studies With Repeated Outcome Measures: Adjusting for Time-Dependent Confounding Using Conventional Methods.

PubMed

Keogh, Ruth H; Daniel, Rhian M; VanderWeele, Tyler J; Vansteelandt, Stijn

2018-05-01

Estimation of causal effects of time-varying exposures using longitudinal data is a common problem in epidemiology. When there are time-varying confounders, which may include past outcomes, affected by prior exposure, standard regression methods can lead to bias. Methods such as inverse probability weighted estimation of marginal structural models have been developed to address this problem. However, in this paper we show how standard regression methods can be used, even in the presence of time-dependent confounding, to estimate the total effect of an exposure on a subsequent outcome by controlling appropriately for prior exposures, outcomes, and time-varying covariates. We refer to the resulting estimation approach as sequential conditional mean models (SCMMs), which can be fitted using generalized estimating equations. We outline this approach and describe how including propensity score adjustment is advantageous. We compare the causal effects being estimated using SCMMs and marginal structural models, and we compare the two approaches using simulations. SCMMs enable more precise inferences, with greater robustness against model misspecification via propensity score adjustment, and easily accommodate continuous exposures and interactions. A new test for direct effects of past exposures on a subsequent outcome is described.

Development of a hydraulic model of the human systemic circulation

NASA Technical Reports Server (NTRS)

Sharp, M. K.; Dharmalingham, R. K.

1999-01-01

Physical and numeric models of the human circulation are constructed for a number of objectives, including studies and training in physiologic control, interpretation of clinical observations, and testing of prosthetic cardiovascular devices. For many of these purposes it is important to quantitatively validate the dynamic response of the models in terms of the input impedance (Z = oscillatory pressure/oscillatory flow). To address this need, the authors developed an improved physical model. Using a computer study, the authors first identified the configuration of lumped parameter elements in a model of the systemic circulation; the result was a good match with human aortic input impedance with a minimum number of elements. Design, construction, and testing of a hydraulic model analogous to the computer model followed. Numeric results showed that a three element model with two resistors and one compliance produced reasonable matching without undue complication. The subsequent analogous hydraulic model included adjustable resistors incorporating a sliding plate to vary the flow area through a porous material and an adjustable compliance consisting of a variable-volume air chamber. The response of the hydraulic model compared favorably with other circulation models.

The Predictive Role of Values and Perceived Social Support Variables in Marital Adjustment

ERIC Educational Resources Information Center

Mert, Abdullah

2018-01-01

The aim of this study was to examine the predictive role of values and perceived social support variables in marital adjustment level among married individuals. A total of 422 (211 pairs) married individuals who agreed to participate voluntarily were included. The study was conducted in accordance with the relational screening model. "Dyadic…

The Collaborative Career Adjustment Project (CCAP): A Model to Recruit and Retain Speech-Language Pathologists in Rural Communities.

ERIC Educational Resources Information Center

Farmer, Stephen S.

1994-01-01

Describes the Collaborative Career Adjustment Project, a program that allows licensed teachers in rural New Mexico to continue teaching while taking weekend, summer, or distance education courses to obtain a master's degree in speech-language pathology. Includes recommendations for the recruitment and retention of rural students in communication…

Risk Adjustment for Medicare Total Knee Arthroplasty Bundled Payments.

PubMed

Clement, R Carter; Derman, Peter B; Kheir, Michael M; Soo, Adrianne E; Flynn, David N; Levin, L Scott; Fleisher, Lee

2016-09-01

The use of bundled payments is growing because of their potential to align providers and hospitals on the goal of cost reduction. However, such gain sharing could incentivize providers to "cherry-pick" more profitable patients. Risk adjustment can prevent this unintended consequence, yet most bundling programs include minimal adjustment techniques. This study was conducted to determine how bundled payments for total knee arthroplasty (TKA) should be adjusted for risk. The authors collected financial data for all Medicare patients (age≥65 years) undergoing primary unilateral TKA at an academic center over a period of 2 years (n=941). Multivariate regression was performed to assess the effect of patient factors on the costs of acute inpatient care, including unplanned 30-day readmissions. This analysis mirrors a bundling model used in the Medicare Bundled Payments for Care Improvement initiative. Increased age, American Society of Anesthesiologists (ASA) class, and the presence of a Medicare Major Complications/Comorbid Conditions (MCC) modifier (typically representing major complications) were associated with increased costs (regression coefficients, $57 per year; $729 per ASA class beyond I; and $3122 for patients meeting MCC criteria; P=.003, P=.001, and P<.001, respectively). Differences in costs were not associated with body mass index, sex, or race. If the results are generalizable, Medicare bundled payments for TKA encompassing acute inpatient care should be adjusted upward by the stated amounts for older patients, those with elevated ASA class, and patients meeting MCC criteria. This is likely an underestimate for many bundling models, including the Comprehensive Care for Joint Replacement program, incorporating varying degrees of postacute care. Failure to adjust for factors that affect costs may create adverse incentives, creating barriers to care for certain patient populations. [Orthopedics. 2016; 39(5):e911-e916.]. Copyright 2016, SLACK Incorporated.

Isolating the Effects of the Warming Trend from the General Climate Change in Water Resources: California Case

NASA Astrophysics Data System (ADS)

Wang, J.; Yin, H.; Chung, F.

2008-12-01

While the population growth, the future land use change, and the desire for better environmental preservation and protection are adding up pressure on water resources management in California, California is facing an extra challenge of addressing potential climate change impacts on water supple and demand in California. The concerns on water facilities planning and flood control caused by climate change include modified precipitation patterns, changes in snow levels and runoff patterns due to increased air temperatures. Although long-term climate projections are largely uncertain, there appears to be a strong consistency in predicting the warming trend of future surface temperature, and the resulting shift in the seasonal patterns of runoff. However, projected changes in precipitation (wetting or drying), which control annual runoff, are far less certain. This paper attempts to separate the effects of warming trend from the effects of precipitation trend on water planning especially in California where reservoir operations are more sensitive to seasonal patterns of runoff than to the total annual runoff. The water resources systems planning model, CALSIM2, is used to evaluate climate change impact on water resource management in California. Rather than directly ingesting estimated streamflows from climate model projections into CALSIM2, a three step perturbation ratio method is proposed to introduce climate change impact into the planning model. Firstly, monthly perturbation ratio of projected monthly inflow to simulated historical monthly inflow is applied to observed historical monthly inflow to generate climate change inflows to major dams and reservoirs. To isolate the effects of warming trend on water resources, a further annual inflow adjustment is applied to the inflows generated in step one to preserve the volume of the observed annual inflow. To re-introduce the effects of precipitation trend on water resources, an additional inflow trend adjustment is applied to the adjusted climate change inflow. Therefore, three CALSIM2 experiments will be implemented: (1) base run with the observed historic inflow (1921 to 2003); (2) sensitivity run with the adjusted climate change inflow through annual inflow adjustment; (3) sensitivity run with the adjusted climate change inflow through annual inflow adjustment and inflow trend adjustment. To account for the variability of various climate models in projecting future climates, the uncertainty in future emission scenarios, and the difference in different projection periods, estimated inflows from 6 climate models for 2 emission scenarios (A2 and B1) and two projection periods (2030-2059 and 2070-2099) are included in the CALSIM model experiments.

Influence of socioeconomic status on trauma center performance evaluations in a Canadian trauma system.

PubMed

Moore, Lynne; Turgeon, Alexis F; Sirois, Marie-Josée; Murat, Valérie; Lavoie, André

2011-09-01

Trauma center performance evaluations generally include adjustment for injury severity, age, and comorbidity. However, disparities across trauma centers may be due to other differences in source populations that are not accounted for, such as socioeconomic status (SES). We aimed to evaluate whether SES influences trauma center performance evaluations in an inclusive trauma system with universal access to health care. The study was based on data collected between 1999 and 2006 in a Canadian trauma system. Patient SES was quantified using an ecologic index of social and material deprivation. Performance evaluations were based on mortality adjusted using the Trauma Risk Adjustment Model. Agreement between performance results with and without additional adjustment for SES was evaluated with correlation coefficients. The study sample comprised a total of 71,784 patients from 48 trauma centers, including 3,828 deaths within 30 days (4.5%) and 5,549 deaths within 6 months (7.7%). The proportion of patients in the highest quintile of social and material deprivation varied from 3% to 43% and from 11% to 90% across hospitals, respectively. The correlation between performance results with or without adjustment for SES was almost perfect (r = 0.997; 95% CI 0.995-0.998) and the same hospital outliers were identified. We observed an important variation in SES across trauma centers but no change in risk-adjusted mortality estimates when SES was added to adjustment models. Results suggest that after adjustment for injury severity, age, comorbidity, and transfer status, disparities in SES across trauma center source populations do not influence trauma center performance evaluations in a system offering universal health coverage. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Performance of comorbidity, risk adjustment, and functional status measures in expenditure prediction for patients with diabetes.

PubMed

Maciejewski, Matthew L; Liu, Chuan-Fen; Fihn, Stephan D

2009-01-01

To compare the ability of generic comorbidity and risk adjustment measures, a diabetes-specific measure, and a self-reported functional status measure to explain variation in health care expenditures for individuals with diabetes. This study included a retrospective cohort of 3,092 diabetic veterans participating in a multisite trial. Two comorbidity measures, four risk adjusters, a functional status measure, a diabetes complication count, and baseline expenditures were constructed from administrative and survey data. Outpatient, inpatient, and total expenditure models were estimated using ordinary least squares regression. Adjusted R(2) statistics and predictive ratios were compared across measures to assess overall explanatory power and explanatory power of low- and high-cost subgroups. Administrative data-based risk adjusters performed better than the comorbidity, functional status, and diabetes-specific measures in all expenditure models. The diagnostic cost groups (DCGs) measure had the greatest predictive power overall and for the low- and high-cost subgroups, while the diabetes-specific measure had the lowest predictive power. A model with DCGs and the diabetes-specific measure modestly improved predictive power. Existing generic measures can be useful for diabetes-specific research and policy applications, but more predictive diabetes-specific measures are needed.

Adjustable Autonomy Testbed

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schrenkenghost, Debra K.

2001-01-01

The Adjustable Autonomy Testbed (AAT) is a simulation-based testbed located in the Intelligent Systems Laboratory in the Automation, Robotics and Simulation Division at NASA Johnson Space Center. The purpose of the testbed is to support evaluation and validation of prototypes of adjustable autonomous agent software for control and fault management for complex systems. The AA T project has developed prototype adjustable autonomous agent software and human interfaces for cooperative fault management. This software builds on current autonomous agent technology by altering the architecture, components and interfaces for effective teamwork between autonomous systems and human experts. Autonomous agents include a planner, flexible executive, low level control and deductive model-based fault isolation. Adjustable autonomy is intended to increase the flexibility and effectiveness of fault management with an autonomous system. The test domain for this work is control of advanced life support systems for habitats for planetary exploration. The CONFIG hybrid discrete event simulation environment provides flexible and dynamically reconfigurable models of the behavior of components and fluids in the life support systems. Both discrete event and continuous (discrete time) simulation are supported, and flows and pressures are computed globally. This provides fast dynamic simulations of interacting hardware systems in closed loops that can be reconfigured during operations scenarios, producing complex cascading effects of operations and failures. Current object-oriented model libraries support modeling of fluid systems, and models have been developed of physico-chemical and biological subsystems for processing advanced life support gases. In FY01, water recovery system models will be developed.

Parents' Perceived Discrimination and Adolescent Adjustment in Chinese American Families: Mediating Family Processes.

PubMed

Hou, Yang; Kim, Su Yeong; Hazen, Nancy; Benner, Aprile D

2017-01-01

Parental discriminatory experiences can have significant implications for adolescent adjustment. This study examined family processes linking parental perceived discrimination to adolescent depressive symptoms and delinquent behaviors by using the family stress model and incorporating family systems theory. Participants were 444 Chinese American adolescents (M age.wave1  = 13.03) and their parents residing in Northern California. Testing of actor-partner interdependent models showed a significant indirect effect from earlier paternal (but not maternal) perceived discrimination to later adolescent adjustment through paternal depressive symptoms and maternal hostility toward adolescents. The results highlight the importance of including both parents and examining actor and partner effects to provide a more comprehensive understanding of how maternal and paternal perceived discrimination differentially and indirectly relate to adolescent adjustment. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Variational assimilation of streamflow into operational distributed hydrologic models: effect of spatiotemporal adjustment scale

NASA Astrophysics Data System (ADS)

Lee, H.; Seo, D.-J.; Liu, Y.; Koren, V.; McKee, P.; Corby, R.

2012-01-01

State updating of distributed rainfall-runoff models via streamflow assimilation is subject to overfitting because large dimensionality of the state space of the model may render the assimilation problem seriously under-determined. To examine the issue in the context of operational hydrology, we carry out a set of real-world experiments in which streamflow data is assimilated into gridded Sacramento Soil Moisture Accounting (SAC-SMA) and kinematic-wave routing models of the US National Weather Service (NWS) Research Distributed Hydrologic Model (RDHM) with the variational data assimilation technique. Study basins include four basins in Oklahoma and five basins in Texas. To assess the sensitivity of data assimilation performance to dimensionality reduction in the control vector, we used nine different spatiotemporal adjustment scales, where state variables are adjusted in a lumped, semi-distributed, or distributed fashion and biases in precipitation and potential evaporation (PE) are adjusted hourly, 6-hourly, or kept time-invariant. For each adjustment scale, three different streamflow assimilation scenarios are explored, where streamflow observations at basin interior points, at the basin outlet, or at both interior points and the outlet are assimilated. The streamflow assimilation experiments with nine different basins show that the optimum spatiotemporal adjustment scale varies from one basin to another and may be different for streamflow analysis and prediction in all of the three streamflow assimilation scenarios. The most preferred adjustment scale for seven out of nine basins is found to be the distributed, hourly scale, despite the fact that several independent validation results at this adjustment scale indicated the occurrence of overfitting. Basins with highly correlated interior and outlet flows tend to be less sensitive to the adjustment scale and could benefit more from streamflow assimilation. In comparison to outlet flow assimilation, interior flow assimilation at any adjustment scale produces streamflow predictions with a spatial correlation structure more consistent with that of streamflow observations. We also describe diagnosing the complexity of the assimilation problem using the spatial correlation information associated with the streamflow process, and discuss the effect of timing errors in a simulated hydrograph on the performance of the data assimilation procedure.

Radiative Forcing in the ACCMIP Historical and Future Climate Simulations

NASA Technical Reports Server (NTRS)

Shindell, Drew Todd; Lamarque, J.-F.; Schulz, M.; Flanner, M.; Jiao, C.; Chin, M.; Young, P. J.; Lee, Y. H.; Rotstayn, L.; Mahowald, N.;

Functional form and risk adjustment of hospital costs: Bayesian analysis of a Box-Cox random coefficients model.

PubMed

Hollenbeak, Christopher S

2005-10-15

While risk-adjusted outcomes are often used to compare the performance of hospitals and physicians, the most appropriate functional form for the risk adjustment process is not always obvious for continuous outcomes such as costs. Semi-log models are used most often to correct skewness in cost data, but there has been limited research to determine whether the log transformation is sufficient or whether another transformation is more appropriate. This study explores the most appropriate functional form for risk-adjusting the cost of coronary artery bypass graft (CABG) surgery. Data included patients undergoing CABG surgery at four hospitals in the midwest and were fit to a Box-Cox model with random coefficients (BCRC) using Markov chain Monte Carlo methods. Marginal likelihoods and Bayes factors were computed to perform model comparison of alternative model specifications. Rankings of hospital performance were created from the simulation output and the rankings produced by Bayesian estimates were compared to rankings produced by standard models fit using classical methods. Results suggest that, for these data, the most appropriate functional form is not logarithmic, but corresponds to a Box-Cox transformation of -1. Furthermore, Bayes factors overwhelmingly rejected the natural log transformation. However, the hospital ranking induced by the BCRC model was not different from the ranking produced by maximum likelihood estimates of either the linear or semi-log model. Copyright (c) 2005 John Wiley & Sons, Ltd.

Review and Implementation Status of Prior Defense Business Board Recommendations

DTIC Science & Technology

2007-04-01

Resource Management • Support unified models for shared services , and be prepared to adjust forward approaches for a Unified Medical Command...models for shared services – including by and between Veterans Affairs and Defense, electronic information exchange, disease treatment and prevention...www.dod.mil/dbb/pdf/DBB- Report-on-the-Military.pdf. • Continue to support unified models for shared services – including by and between Veterans Affairs

SfM with MRFs: discrete-continuous optimization for large-scale structure from motion.

PubMed

Crandall, David J; Owens, Andrew; Snavely, Noah; Huttenlocher, Daniel P

2013-12-01

Recent work in structure from motion (SfM) has built 3D models from large collections of images downloaded from the Internet. Many approaches to this problem use incremental algorithms that solve progressively larger bundle adjustment problems. These incremental techniques scale poorly as the image collection grows, and can suffer from drift or local minima. We present an alternative framework for SfM based on finding a coarse initial solution using hybrid discrete-continuous optimization and then improving that solution using bundle adjustment. The initial optimization step uses a discrete Markov random field (MRF) formulation, coupled with a continuous Levenberg-Marquardt refinement. The formulation naturally incorporates various sources of information about both the cameras and points, including noisy geotags and vanishing point (VP) estimates. We test our method on several large-scale photo collections, including one with measured camera positions, and show that it produces models that are similar to or better than those produced by incremental bundle adjustment, but more robustly and in a fraction of the time.

Worldwide impact of economic cycles on suicide trends over 3 decades: differences according to level of development. A mixed effect model study

PubMed Central

Perez-Rodriguez, M Mercedes; Garcia-Nieto, Rebeca; Fernandez-Navarro, Pablo; Galfalvy, Hanga; de Leon, Jose; Baca-Garcia, Enrique

2012-01-01

Objectives To investigate the trends and correlations of gross domestic product (GDP) adjusted for purchasing power parity (PPP) per capita on suicide rates in 10 WHO regions during the past 30 years. Design Analyses of databases of PPP-adjusted GDP per capita and suicide rates. Countries were grouped according to the Global Burden of Disease regional classification system. Data sources World Bank's official website and WHO's mortality database. Statistical analyses After graphically displaying PPP-adjusted GDP per capita and suicide rates, mixed effect models were used for representing and analysing clustered data. Results Three different groups of countries, based on the correlation between the PPP-adjusted GDP per capita and suicide rates, are reported: (1) positive correlation: developing (lower middle and upper middle income) Latin-American and Caribbean countries, developing countries in the South East Asian Region including India, some countries in the Western Pacific Region (such as China and South Korea) and high-income Asian countries, including Japan; (2) negative correlation: high-income and developing European countries, Canada, Australia and New Zealand and (3) no correlation was found in an African country. Conclusions PPP-adjusted GDP per capita may offer a simple measure for designing the type of preventive interventions aimed at lowering suicide rates that can be used across countries. Public health interventions might be more suitable for developing countries. In high-income countries, however, preventive measures based on the medical model might prove more useful. PMID:22586285

THE RELATIONSHIP BETWEEN SEX HORMONES, SEX HORMONE BINDING GLOBULIN AND PERIPHERAL ARTERY DISEASE IN OLDER PERSONS

PubMed Central

Maggio, M; Cattabiani, C; Lauretani, F; Artoni, A; Bandinelli, S; Schiavi, G; Vignali, A; Volpi, R; Ceresini, G; Lippi, G; Aloe, R; De Vita, F; Giallauria, F; McDermott, MM; Ferrucci, L; Ceda, GP

2014-01-01

Objective The prevalence of peripheral artery disease (PAD) increases with aging and is higher in persons with metabolic syndrome and diabetes. PAD is associated with adverse outcomes, including frailty and disability. The protective effect of testosterone and sex hormone binding globulin (SHBG) for diabetes in men suggests that the biological activity of sex hormones may affect PAD, especially in older populations. Methods Nine hundred and twenty-one elderly subjects with data on SHBG, testosterone (T), estradiol (E2) were selected from InCHIANTI study. PAD was defined as an Ankle-Brachial Index (ABI) <0.90. Logistic regression models adjusted for age (Model 1), age, BMI, insulin, interleukin-6, physical activity, smoking, chronic diseases including metabolic syndrome (Model 2), and a final model including also sex hormones (Model 3) were performed to test the relationship between SHBG, sex hormones and PAD. Results The mean age (± SD) of the 419 men and 502 women was 75.0 ± 6.8 years (Sixty two participants (41 men, 21 women) had ABI<0.90. Men with PAD had SHBG levels lower than men without PAD (p=0.03). SHBG was negatively and independently associated with PAD in men (p=0.028). but not in women. The relationship was however attenuated after adjusting for sex hormones (p=0.07). The E2 was not significantly associated with PAD in both men and women. In women, but not in men, T was positively associated with PAD, even after adjusting for multiple confounders, including E2 (p=0.01). Conclusions Low SHBG and high T levels are significantly and independently associated with the presence of PAD in older men and women, respectively. PMID:23102785

The relationship between sex hormones, sex hormone binding globulin and peripheral artery disease in older persons.

PubMed

Maggio, M; Cattabiani, C; Lauretani, F; Artoni, A; Bandinelli, S; Schiavi, G; Vignali, A; Volpi, R; Ceresini, G; Lippi, G; Aloe, R; De Vita, F; Giallauria, F; McDermott, M M; Ferrucci, L; Ceda, G P

2012-12-01

The prevalence of peripheral artery disease (PAD) increases with aging and is higher in persons with metabolic syndrome and diabetes. PAD is associated with adverse outcomes, including frailty and disability. The protective effect of testosterone and sex hormone binding globulin (SHBG) for diabetes in men suggests that the biological activity of sex hormones may affect PAD, especially in older populations. Nine hundred and twenty-one elderly subjects with data on SHBG, testosterone (T), estradiol (E2) were selected from InCHIANTI study. PAD was defined as an Ankle-Brachial Index (ABI) < 0.90. Logistic regression models adjusted for age (Model 1), age, BMI, insulin, interleukin-6, physical activity, smoking, chronic diseases including metabolic syndrome (Model 2), and a final model including also sex hormones (Model 3) were performed to test the relationship between SHBG, sex hormones and PAD. The mean age (±SD) of the 419 men and 502 women was 75.0 ± 6.8 years. Sixty two participants (41 men, 21 women) had ABI < 0.90. Men with PAD had SHBG levels lower than men without PAD (p = 0.03). SHBG was negatively and independently associated with PAD in men (p = 0.028) but not in women. The relationship was however attenuated after adjusting for sex hormones (p = 0.07). The E2 was not significantly associated with PAD in both men and women. In women, but not in men, T was positively associated with PAD, even after adjusting for multiple confounders, including E2 (p = 0.01). Low SHBG and high T levels are significantly and independently associated with the presence of PAD in older men and women, respectively. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Mathematical Storage-Battery Models

NASA Technical Reports Server (NTRS)

Chapman, C. P.; Aston, M.

1985-01-01

Empirical formula represents performance of electrical storage batteries. Formula covers many battery types and includes numerous coefficients adjusted to fit peculiarities of each type. Battery and load parameters taken into account include power density in battery, discharge time, and electrolyte temperature. Applications include electric-vehicle "fuel" gages and powerline load leveling.

Genetic Parameters of Pre-adjusted Body Weight Growth and Ultrasound Measures of Body Tissue Development in Three Seedstock Pig Breed Populations in Korea

PubMed Central

Choy, Yun Ho; Mahboob, Alam; Cho, Chung Il; Choi, Jae Gwan; Choi, Im Soo; Choi, Tae Jeong; Cho, Kwang Hyun; Park, Byoung Ho

2015-01-01

The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability (h2) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The h2 estimates of DAYS90 from model II and III were also somewhat similar. The h2 for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations (rG) were moderately negative between DAYS90 and BF (−0.29 to −0.38), and between DAYS90 and EMA (−0.16 to −0.26). BF had strong rG with RCP (−0.87 to −0.93). Moderately positive rG existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the rG between DAYS90 and AEMA from model III (0.27 to 0.30). The rG between AEMA and ABF and between AEMA and ARCP were moderate but with negative and positive signs, respectively; also reflected influence of pre-adjustments. However, the rG between BF and RCP remained non-influential to trait pre-adjustments or covariable fits. Therefore, we conclude that ultrasound measures taken at a body weight of about 90 kg as the test final should be adjusted for body weight growth. Our adjustment formulas, particularly those for BF and EMA, should be revised further to accommodate the added variation due to different performance testing endpoints with regard to differential growth in body composition. PMID:26580436

Genetic Parameters of Pre-adjusted Body Weight Growth and Ultrasound Measures of Body Tissue Development in Three Seedstock Pig Breed Populations in Korea.

PubMed

Choy, Yun Ho; Mahboob, Alam; Cho, Chung Il; Choi, Jae Gwan; Choi, Im Soo; Choi, Tae Jeong; Cho, Kwang Hyun; Park, Byoung Ho

2015-12-01

The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability (h(2)) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The h(2) estimates of DAYS90 from model II and III were also somewhat similar. The h(2) for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations (rG) were moderately negative between DAYS90 and BF (-0.29 to -0.38), and between DAYS90 and EMA (-0.16 to -0.26). BF had strong rG with RCP (-0.87 to -0.93). Moderately positive rG existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the rG between DAYS90 and AEMA from model III (0.27 to 0.30). The rG between AEMA and ABF and between AEMA and ARCP were moderate but with negative and positive signs, respectively; also reflected influence of pre-adjustments. However, the rG between BF and RCP remained non-influential to trait pre-adjustments or covariable fits. Therefore, we conclude that ultrasound measures taken at a body weight of about 90 kg as the test final should be adjusted for body weight growth. Our adjustment formulas, particularly those for BF and EMA, should be revised further to accommodate the added variation due to different performance testing endpoints with regard to differential growth in body composition.

Evaluation of average daily gain prediction by level one of the 1996 National Research Council beef model and development of net energy adjusters.

PubMed

Block, H C; Klopfenstein, T J; Erickson, G E

2006-04-01

Two data sets were developed to evaluate and refine feed energy predictions with the beef National Research Council (NRC, 1996) model level 1. The first data set included pen means of group-fed cattle from 31 growing trials (201 observations) and 17 finishing trials (154 observations) representing over 7,700 animals fed outside in dirt lots. The second data set consisted of 15 studies with individually fed cattle (916 observations) fed in a barn. In each data set, actual ADG was compared with ADG predicted with the NRC model level 1, assuming thermoneutral environmental conditions. Next, the observed ADG (kg), TDN intake (kg/d), and TDN concentration (kg/kg of DM) were used to develop equations to adjust the level 1 predicted diet NEm and NEg (diet NE adjusters) to be applied to more accurately predict ADG. In both data sets, the NRC (1996) model level 1 inaccurately predicted ADG (P < 0.001 for slope = 1; intercept = 0 when observed ADG was regressed on predicted ADG). The following nonlinear relationships to adjust NE based on observed ADG, TDN intake, and TDN concentration were all significant (P < 0.001): NE adjuster = 0.7011 x 10(-0.8562 x ADG) + 0.8042, R2 = 0.325, s(y.x) = 0.136 kg; NE adjuster = 4.795 10(-0.3689 x TDN intake) + 0.8233, R2 x = 0.714, s(y.x) = 0.157 kg; and NE adjuster = 357 x 10(-5.449 x TDN concentration) + 0.8138, R2 = 0.754, s(y.x) = 0.127 kg. An NE adjuster < 1 indicates overprediction of ADG. The average NE adjustment required for the pen-fed finishing trials was 0.820, whereas the (P < 0.001) adjustment of 0.906 for individually fed cattle indicates that the pen-fed environment increased NE requirements. The use of these equations should improve ADG prediction by the NRC (1996) model level 1, although the equations reflect limitations of the data from which they were developed and are appropriate only over the range of the developmental data set. There is a need for independent evaluation of the ability of the equations to improve ADG prediction by the NRC (1996) model level 1.

Social Competence in Pediatric Brain Tumor Survivors: Application of a Model from Social Neuroscience and Developmental Psychology

PubMed Central

Hocking, Matthew C.; McCurdy, Mark; Turner, Elise; Kazak, Anne E.; Noll, Robert B.; Phillips, Peter; Barakat, Lamia P.

2014-01-01

Pediatric brain tumor (BT) survivors are at risk for psychosocial late effects across many domains of functioning, including neurocognitive and social. The literature on the social competence of pediatric BT survivors is still developing and future research is needed that integrates developmental and cognitive neuroscience research methodologies to identify predictors of survivor social adjustment and interventions to ameliorate problems. This review discusses the current literature on survivor social functioning through a model of social competence in childhood brain disorder and suggests future directions based on this model. Interventions pursuing change in survivor social adjustment should consider targeting social ecological factors. PMID:25382825

Complementary nonparametric analysis of covariance for logistic regression in a randomized clinical trial setting.

PubMed

Tangen, C M; Koch, G G

1999-03-01

In the randomized clinical trial setting, controlling for covariates is expected to produce variance reduction for the treatment parameter estimate and to adjust for random imbalances of covariates between the treatment groups. However, for the logistic regression model, variance reduction is not obviously obtained. This can lead to concerns about the assumptions of the logistic model. We introduce a complementary nonparametric method for covariate adjustment. It provides results that are usually compatible with expectations for analysis of covariance. The only assumptions required are based on randomization and sampling arguments. The resulting treatment parameter is a (unconditional) population average log-odds ratio that has been adjusted for random imbalance of covariates. Data from a randomized clinical trial are used to compare results from the traditional maximum likelihood logistic method with those from the nonparametric logistic method. We examine treatment parameter estimates, corresponding standard errors, and significance levels in models with and without covariate adjustment. In addition, we discuss differences between unconditional population average treatment parameters and conditional subpopulation average treatment parameters. Additional features of the nonparametric method, including stratified (multicenter) and multivariate (multivisit) analyses, are illustrated. Extensions of this methodology to the proportional odds model are also made.

Assessing Medicare's Approach To Covering New Drugs In Bundled Payments For Oncology.

PubMed

Muldoon, L Daniel; Pelizzari, Pamela M; Lang, Kelsey A; Vandigo, Joe; Pyenson, Bruce S

2018-05-01

New oncology therapies can contribute to survival or quality of life, but payers and policy makers have raised concerns about the cost of these therapies. Similar concerns extend beyond cancer. In seeking a solution, payers are increasingly turning toward value-based payment models in which providers take financial risk for costs and outcomes. These models, including episode payment and bundled payment, create financial gains for providers who reduce cost, but they also create concerns about potential stinting on necessary treatments. One approach, which the Centers for Medicare and Medicaid Services adopted in the Oncology Care Model (OCM), is to partially adjust medical practices' budgets for their use of novel therapies, defined in this case as new oncology drugs or new indications for existing drugs approved after December 31, 2014. In an analysis of the OCM novel therapies adjustment using historical Medicare claims data, we found that the adjustment may provide important financial protection for practices. In a simulation we performed, the adjustment reduced the average loss per treatment episode by $758 (from $807 to $49) for large practices that use novel therapies often. Lessons from the OCM can have implications for other alternative payment models.

Quality of workplace social relationships and perceived health.

PubMed

Rydstedt, Leif W; Head, Jenny; Stansfeld, Stephen A; Woodley-Jones, Davina

2012-06-01

Associations between the quality of social relationships at work and mental and self-reported health were examined to assess whether these associations were independent of job strain. The study was based on cross-sectional survey data from 728 employees (response rate 58%) and included the Demand-Control-(Support) (DC-S) model, six items on the quality of social relationships at the workplace, the General Health Questionnaire (30), and an item on self-reported physical health. Logistic regression analyses were used. A first set of models were run with adjustment for age, sex, and socioeconomic group. A second set of models were run adjusted for the dimensions of the DC-S model. Positive associations were found between the quality of social relationships and mental health as well as self-rated physical health, and these associations remained significant even after adjustment for the dimensions. The findings add support to the Health and Safety Executive stress management standards on social relationships at the workplace.

Bayesian effect estimation accounting for adjustment uncertainty.

PubMed

Wang, Chi; Parmigiani, Giovanni; Dominici, Francesca

2012-09-01

Model-based estimation of the effect of an exposure on an outcome is generally sensitive to the choice of which confounding factors are included in the model. We propose a new approach, which we call Bayesian adjustment for confounding (BAC), to estimate the effect of an exposure of interest on the outcome, while accounting for the uncertainty in the choice of confounders. Our approach is based on specifying two models: (1) the outcome as a function of the exposure and the potential confounders (the outcome model); and (2) the exposure as a function of the potential confounders (the exposure model). We consider Bayesian variable selection on both models and link the two by introducing a dependence parameter, ω, denoting the prior odds of including a predictor in the outcome model, given that the same predictor is in the exposure model. In the absence of dependence (ω= 1), BAC reduces to traditional Bayesian model averaging (BMA). In simulation studies, we show that BAC, with ω > 1, estimates the exposure effect with smaller bias than traditional BMA, and improved coverage. We, then, compare BAC, a recent approach of Crainiceanu, Dominici, and Parmigiani (2008, Biometrika 95, 635-651), and traditional BMA in a time series data set of hospital admissions, air pollution levels, and weather variables in Nassau, NY for the period 1999-2005. Using each approach, we estimate the short-term effects of on emergency admissions for cardiovascular diseases, accounting for confounding. This application illustrates the potentially significant pitfalls of misusing variable selection methods in the context of adjustment uncertainty. © 2012, The International Biometric Society.

Factors associated with positive adjustment in siblings of children with severe emotional disturbance: the role of family resources and community life.

PubMed

Kilmer, Ryan P; Cook, James R; Munsell, Eylin Palamaro; Salvador, Samantha Kane

2010-10-01

This study builds on the scant research involving siblings of children with severe emotional disturbances (SED) and examines: associations between adversity experiences and adjustment among 5- to 10-year-old siblings, and relations among family resources, community life, and sibling adjustment. Caregivers from 100 families completed standardized indicators of sibling adjustment and scales reflecting multiple contextual variables. Results document negative associations between stress exposure and sibling adjustment. Regression models also indicate positive associations between the caregiver-child relationship and broader family resources on sibling behavioral and emotional strengths, even after accounting for adversity experiences; adversity exposure was the prime correlate in regression models involving sibling oppositional behavior. Analyses also suggest that strain related to parenting a child with SED is associated with sibling adjustment. This work documents the needs of these siblings and their family systems and highlights the relevance of not only core proximal influences (e.g., child-caregiver relationship) but also elements of their broader contexts. Implications and recommendations are described, including the need to support plans of care that involve services, supports, or preventive strategies for these siblings. © 2010 American Orthopsychiatric Association.

Independent Verification of Mars-GRAM 2010 with Mars Climate Sounder Data

NASA Technical Reports Server (NTRS)

Justh, Hilary L.; Burns, Kerry L.

2014-01-01

The Mars Global Reference Atmospheric Model (Mars-GRAM) is an engineering-level atmospheric model widely used for diverse mission and engineering applications. Applications of Mars-GRAM include systems design, performance analysis, and operations planning for aerobraking, entry, descent and landing, and aerocapture. Atmospheric influences on landing site selection and long-term mission conceptualization and development can also be addressed utilizing Mars-GRAM. Mars-GRAM's perturbation modeling capability is commonly used, in a Monte Carlo mode, to perform high-fidelity engineering end-to-end simulations for entry, descent, and landing. Mars-GRAM is an evolving software package resulting in improved accuracy and additional features. Mars-GRAM 2005 has been validated against Radio Science data, and both nadir and limb data from the Thermal Emission Spectrometer (TES). From the surface to 80 km altitude, Mars-GRAM is based on the NASA Ames Mars General Circulation Model (MGCM). Above 80 km, Mars-GRAM is based on the University of Michigan Mars Thermospheric General Circulation Model (MTGCM). The most recent release of Mars-GRAM 2010 includes an update to Fortran 90/95 and the addition of adjustment factors. These adjustment factors are applied to the input data from the MGCM and the MTGCM for the mapping year 0 user-controlled dust case. The adjustment factors are expressed as a function of height (z), latitude and areocentric solar longitude (Ls).

Distress and adjustment among adolescents and young adults with cancer: an empirical and conceptual review

PubMed Central

Wakefield, Claire E.

2013-01-01

Adolescents and young adults (AYAs) with cancer must simultaneously navigate the challenges associated with their cancer experience, whilst striving to achieve a number of important developmental milestones at the cusp of adulthood. The disruption caused by their cancer experience at this critical life-stage is assumed to be responsible for significant distress among AYAs living with cancer. The quality and severity of psychological outcomes among AYAs remain poorly documented, however. This review examined the existing literature on psychological outcomes among AYAs living with cancer. All psychological outcomes (both distress and positive adjustment) were included, and AYAs were included across the cancer trajectory, ranging from newly-diagnosed patients, to long-term cancer survivors. Four key research questions were addressed. Section 1 answered the question, “What is the nature and prevalence of distress (and other psychological outcomes) among AYAs living with cancer?” and documented rates of clinical distress, as well as evidence for the trajectory of this distress over time. Section 2 examined the individual, cancer/treatment-related and socio-demographic factors that have been identified as predictors of these outcomes in this existing literature. Section 3 examined current theoretical models relevant to explaining psychological outcomes among AYAs, including developmental models, socio-cognitive and family-systems models, stress-coping frameworks, and cognitive appraisal models (including trauma and meaning making models). The mechanisms implicated in each model were discussed, as was the existing evidence for each model. Converging evidence implicating the potential role of autobiographical memory and future thinking systems in how AYAs process and integrate their cancer experience into their current sense of self and future goals are highlighted. Finally, Section 4 addressed the future of psycho-oncology in understanding and conceptualizing psychological outcomes among AYAs living with cancer, by discussing recent empirical advancements in adjacent, non-oncology fields that might improve our understanding of psychological outcomes in AYAs living with cancer. Included in these were models of memory and future thinking drawn from the broader psychology literature that identify important mechanisms involved in adjustment, as well as experimental paradigms for the study of these mechanisms within analogue, non-cancer AYA samples. PMID:26835313

Design and application of a technologically explicit hybrid energy-economy policy model with micro and macro economic dynamics

NASA Astrophysics Data System (ADS)

Bataille, Christopher G. F.

2005-11-01

Are further energy efficiency gains, or more recently greenhouse gas reductions, expensive or cheap? Analysts provide conflicting advice to policy makers based on divergent modelling perspectives, a 'top-down/bottom-up debate' in which economists use equation based models that equilibrate markets by maximizing consumer welfare, and technologists use technology simulation models that minimize the financial cost of providing energy services. This thesis summarizes a long term research project to find a middle ground between these two positions that is more useful to policy makers. Starting with the individual components of a behaviourally realistic and technologically explicit simulation model (ISTUM---Inter Sectoral Technology Use Model), or "hybrid", the individual sectors of the economy are linked using a framework of micro and macro economic feedbacks. These feedbacks are taken from the economic theory that informs the computable general equilibrium (CGE) family of models. Speaking in the languages of both economists and engineers, the resulting "physical" equilibrium model of Canada (CIMS---Canadian Integrated Modeling System), equilibrates energy and end-product markets, including imports and exports, for seven regions and 15 economic sectors, including primary industry, manufacturing, transportation, commerce, residences, governmental infrastructure and the energy supply sectors. Several different policy experiments demonstrate the value-added of the model and how its results compare to top-down and bottom-up practice. In general, the results show that technical adjustments make up about half the response to simulated energy policy, and macroeconomic demand adjustments the other half. Induced technical adjustments predominate with minor policies, while the importance of macroeconomic demand adjustment increases with the strength of the policy. Results are also shown for an experiment to derive estimates of future elasticity of substitution (ESUB) and autonomous energy efficiency indices (AEEI) from the model, parameters that could be used in long-run computable general equilibrium (CGE) analysis. The thesis concludes with a summary of the strengths and weakness of the new model as a policy tool, a work plan for its further improvement, and a discussion of the general potential for technologically explicit general equilibrium modelling.

The necessity of sociodemographic status adjustment in hospital value rankings for perforated appendicitis in children.

PubMed

Tian, Yao; Sweeney, John F; Wulkan, Mark L; Heiss, Kurt F; Raval, Mehul V

2016-06-01

Hospitals are increasingly focused on demonstration of high-value care for common surgical procedures. Although sociodemographic status (SDS) factors have been tied to various surgical outcomes, the impact of SDS factors on hospital value rankings has not been well explored. Our objective was to examine effects of SDS factors on high-value surgical care at the patient level, and to illustrate the importance of SDS adjustment when evaluating hospital-level performance. Perforated appendicitis hospitalizations were identified from the 2012 Kids' Inpatient Database. The primary outcome of interest was high-value care as defined by evaluation of duration of stay and cost. SDS factors included race, health insurance type, median household income, and patient location. The impact of SDS on high-value care was estimated using regression models after accounting for hospital-level variation. Risk-adjusted value rankings were compared before and after adjustment for SDS. From 9,986 hospitalizations, 998 high-value encounters were identified. African Americans were less likely to experience high-value care compared with white patients after adjusting for all SDS variables. Although private insurance and living in nonmetro counties were associated independently with high-value care, the effects were attenuated in the fully adjusted models. For the 136 hospitals ranked according to risk-adjusted value status, 59 hospitals' rankings improved after adjustment and 53 hospitals' rankings declined. After adjustment for patient and hospital factors, SDS has a small but significant impact on risk-adjusted hospital performance ranking for pediatric appendicitis. Adjustment for SDS should be considered in future comparative performance assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

Macro-level gender equality and alcohol consumption: a multi-level analysis across U.S. States.

PubMed

Roberts, Sarah C M

2012-07-01

Higher levels of women's alcohol consumption have long been attributed to increases in gender equality. However, only limited research examines the relationship between gender equality and alcohol consumption. This study examined associations between five measures of state-level gender equality and five alcohol consumption measures in the United States. Survey data regarding men's and women's alcohol consumption from the 2005 Behavioral Risk Factor Surveillance System were linked to state-level indicators of gender equality. Gender equality indicators included state-level women's socioeconomic status, gender equality in socioeconomic status, reproductive rights, policies relating to violence against women, and women's political participation. Alcohol consumption measures included past 30-day drinker status, drinking frequency, binge drinking, volume, and risky drinking. Other than drinker status, consumption is measured for drinkers only. Multi-level linear and logistic regression models adjusted for individual demographics as well as state-level income inequality, median income, and % Evangelical Protestant/Mormon. All gender equality indicators were positively associated with both women's and men's drinker status in models adjusting only for individual-level covariates; associations were not significant in models adjusting for other state-level characteristics. All other associations between gender equality and alcohol consumption were either negative or non-significant for both women and men in models adjusting for other state-level factors. Findings do not support the hypothesis that higher levels of gender equality are associated with higher levels of alcohol consumption by women or by men. In fact, most significant findings suggest that higher levels of equality are associated with less alcohol consumption overall. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of vitamin D on the hospitalization rate of Crohn's disease patients seen at a tertiary care center

PubMed Central

Venkata, Krishna V R; Arora, Sumant S; Xie, Feng-Long; Malik, Talha A

2017-01-01

AIM To study the association between vitamin D level and hospitalization rate in Crohn’s disease (CD) patients. METHODS We designed a retrospective cohort study using adult patients (> 19 years) with CD followed for at least one year at our inflammatory bowel disease center. Vitamin D levels were divided into: low mean vitamin D level (< 30 ng/mL) vs appropriate mean vitamin D level (30-100 ng/mL). Generalized Poisson Regression Models (GPR) for Rate Data were used to estimate partially adjusted and fully adjusted incidence rate ratios (IRR) of hospitalization among CD patients. We also examined IRRs for vitamin D level as a continuous variable. RESULTS Of the 880 CD patients, 196 patients with vitamin D level during the observation period were included. Partially adjusted model demonstrated that CD patients with a low mean vitamin D level were almost twice more likely to be admitted (IRR = 1.76, 95%CI: 1.38-2.24) compared to those with an appropriate vitamin D level. The fully adjusted model confirmed this association (IRR = 1.44, 95%CI: 1.11-1.87). Partially adjusted model with vitamin D level as a continuous variable demonstrated, higher mean vitamin D level was associated with a 3% lower likelihood of admission with every unit (ng/mL) rise in mean vitamin D level (IRR = 0.97, 95%CI: 0.96-0.98). The fully adjusted model confirmed this association (IRR = 0.98, 95%CI: 0.97-0.99). CONCLUSION Normal or adequate vitamin D stores may be protective in the clinical course of CD. However, this role needs to be further characterized and understood. PMID:28465638

Simulation-Based Evaluation of Dose-Titration Algorithms for Rapid-Acting Insulin in Subjects with Type 2 Diabetes Mellitus Inadequately Controlled on Basal Insulin and Oral Antihyperglycemic Medications.

PubMed

Ma, Xiaosu; Chien, Jenny Y; Johnson, Jennal; Malone, James; Sinha, Vikram

2017-08-01

The purpose of this prospective, model-based simulation approach was to evaluate the impact of various rapid-acting mealtime insulin dose-titration algorithms on glycemic control (hemoglobin A1c [HbA1c]). Seven stepwise, glucose-driven insulin dose-titration algorithms were evaluated with a model-based simulation approach by using insulin lispro. Pre-meal blood glucose readings were used to adjust insulin lispro doses. Two control dosing algorithms were included for comparison: no insulin lispro (basal insulin+metformin only) or insulin lispro with fixed doses without titration. Of the seven dosing algorithms assessed, daily adjustment of insulin lispro dose, when glucose targets were met at pre-breakfast, pre-lunch, and pre-dinner, sequentially, demonstrated greater HbA1c reduction at 24 weeks, compared with the other dosing algorithms. Hypoglycemic rates were comparable among the dosing algorithms except for higher rates with the insulin lispro fixed-dose scenario (no titration), as expected. The inferior HbA1c response for the "basal plus metformin only" arm supports the additional glycemic benefit with prandial insulin lispro. Our model-based simulations support a simplified dosing algorithm that does not include carbohydrate counting, but that includes glucose targets for daily dose adjustment to maintain glycemic control with a low risk of hypoglycemia.

The Rothermel surface fire spread model and associated developments: A comprehensive explanation

Treesearch

Patricia L. Andrews

2018-01-01

The Rothermel surface fire spread model, with some adjustments by Frank A. Albini in 1976, has been used in fire and fuels management systems since 1972. It is generally used with other models including fireline intensity and flame length. Fuel models are often used to define fuel input parameters. Dynamic fuel models use equations for live fuel curing. Models have...

Generalized Adaptive Artificial Neural Networks

NASA Technical Reports Server (NTRS)

Tawel, Raoul

1993-01-01

Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

Modeling erosion under future climates with the WEPP model

Treesearch

Timothy Bayley; William Elliot; Mark A. Nearing; D. Phillp Guertin; Thomas Johnson; David Goodrich; Dennis Flanagan

2010-01-01

The Water Erosion Prediction Project Climate Assessment Tool (WEPPCAT) was developed to be an easy-to-use, web-based erosion model that allows users to adjust climate inputs for user-specified climate scenarios. WEPPCAT allows the user to modify monthly mean climate parameters, including maximum and minimum temperatures, number of wet days, precipitation, and...

Relationship between Carotenoids, Retinol, and Estradiol Levels in Older Women

PubMed Central

Maggio, Marcello; de Vita, Francesca; Lauretani, Fulvio; Bandinelli, Stefania; Semba, Richard D.; Bartali, Benedetta; Cherubini, Antonio; Cappola, Anne R.; Ceda, Gian Paolo; Ferrucci, Luigi

2015-01-01

Background. In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. Methods. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998–2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. Results. After adjustment for age, α-carotene (β ± SE = −0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = −0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = −1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = −0.29 ± 0.08, p = 0.0009), and E2 persisted whereas the relationship between α-carotene and T/E2 ratio was attenuated (β ± SE = 0.22 ± 0.12, p = 0.07). In a fully adjusted model (Model 3), only β-carotene (β ± SE = −0.05 ± 0.02, p = 0.03) was significantly and inversely associated with E2 levels independent of α-carotene. No association was found between retinol, total non-pro-vitamin A carotenoids, lutein, zeaxanthin, and lycopene, and E2 levels. Conclusions: In older women, β-carotene levels are independently and inversely associated with E2. PMID:26251919

Relationship between Carotenoids, Retinol, and Estradiol Levels in Older Women.

PubMed

Maggio, Marcello; de Vita, Francesca; Lauretani, Fulvio; Bandinelli, Stefania; Semba, Richard D; Bartali, Benedetta; Cherubini, Antonio; Cappola, Anne R; Ceda, Gian Paolo; Ferrucci, Luigi

2015-08-05

In vitro evidence suggests anti-estrogenic properties for retinol and carotenoids, supporting a chemo-preventive role of these phytochemicals in estrogen-dependent cancers. During aging there are significant reductions in retinol and carotenoid concentrations, whereas estradiol levels decline during menopause and progressively increase from the age of 65. We aimed to investigate the hypothesis of a potential relationship between circulating levels of retinol, carotenoids, and estradiol (E2) in a cohort of late post-menopausal women. We examined 512 women ≥ 65 years from the InCHIANTI study. Retinol, α-caroten, β-caroten, β-criptoxantin, lutein, zeaxanthin, and lycopene levels were assayed at enrollment (1998-2000) by High-Performance Liquid Chromatography. Estradiol and testosterone (T) levels were assessed by Radioimmunometry (RIA) and testosterone-to-estradiol ratio (T/E2), as a proxy of aromatase activity, was also calculated. General linear models adjusted for age (Model 1) and further adjusted for other confounders including Body Mass Index (BMI) BMI, smoking, intake of energy, lipids, and vitamin A; C-Reactive Protein, insulin, total cholesterol, liver function, and testosterone (Model 2) were used to investigate the relationship between retinol, carotenoids, and E2 levels. To address the independent relationship between carotenoids and E2 levels, factors significantly associated with E2 in Model 2 were also included in a fully adjusted Model 3. After adjustment for age, α-carotene (β ± SE = -0.01 ± 0.004, p = 0.02) and β-carotene (β ± SE = -0.07 ± 0.02, p = 0.0007) were significantly and inversely associated with E2 levels. α-Carotene was also significantly and positively associated with T/E2 ratio (β ± SE = 0.07 ± 0.03, p = 0.01). After adjustment for other confounders (Model 2), the inverse relationship between α-carotene (β ± SE = -1.59 ± 0.61, p = 0.01), β-carotene (β ± SE = -0.29 ± 0.08, p = 0.0009), and E2 persisted whereas the relationship between α-carotene and T/E2 ratio was attenuated (β ± SE = 0.22 ± 0.12, p = 0.07). In a fully adjusted model (Model 3), only β-carotene (β ± SE = -0.05 ± 0.02, p = 0.03) was significantly and inversely associated with E2 levels independent of α-carotene. No association was found between retinol, total non-pro-vitamin A carotenoids, lutein, zeaxanthin, and lycopene, and E2 levels. In older women, β-carotene levels are independently and inversely associated with E2.

Risk-adjusted antibiotic consumption in 34 public acute hospitals in Ireland, 2006 to 2014

PubMed Central

Oza, Ajay; Donohue, Fionnuala; Johnson, Howard; Cunney, Robert

2016-01-01

As antibiotic consumption rates between hospitals can vary depending on the characteristics of the patients treated, risk-adjustment that compensates for the patient-based variation is required to assess the impact of any stewardship measures. The aim of this study was to investigate the usefulness of patient-based administrative data variables for adjusting aggregate hospital antibiotic consumption rates. Data on total inpatient antibiotics and six broad subclasses were sourced from 34 acute hospitals from 2006 to 2014. Aggregate annual patient administration data were divided into explanatory variables, including major diagnostic categories, for each hospital. Multivariable regression models were used to identify factors affecting antibiotic consumption. Coefficient of variation of the root mean squared errors (CV-RMSE) for the total antibiotic usage model was very good (11%), however, the value for two of the models was poor (> 30%). The overall inpatient antibiotic consumption increased from 82.5 defined daily doses (DDD)/100 bed-days used in 2006 to 89.2 DDD/100 bed-days used in 2014; the increase was not significant after risk-adjustment. During the same period, consumption of carbapenems increased significantly, while usage of fluoroquinolones decreased. In conclusion, patient-based administrative data variables are useful for adjusting hospital antibiotic consumption rates, although additional variables should also be employed. PMID:27541730

Performance of Comorbidity, Risk Adjustment, and Functional Status Measures in Expenditure Prediction for Patients With Diabetes

PubMed Central

Maciejewski, Matthew L.; Liu, Chuan-Fen; Fihn, Stephan D.

2009-01-01

OBJECTIVE—To compare the ability of generic comorbidity and risk adjustment measures, a diabetes-specific measure, and a self-reported functional status measure to explain variation in health care expenditures for individuals with diabetes. RESEARCH DESIGN AND METHODS—This study included a retrospective cohort of 3,092 diabetic veterans participating in a multisite trial. Two comorbidity measures, four risk adjusters, a functional status measure, a diabetes complication count, and baseline expenditures were constructed from administrative and survey data. Outpatient, inpatient, and total expenditure models were estimated using ordinary least squares regression. Adjusted R2 statistics and predictive ratios were compared across measures to assess overall explanatory power and explanatory power of low- and high-cost subgroups. RESULTS—Administrative data–based risk adjusters performed better than the comorbidity, functional status, and diabetes-specific measures in all expenditure models. The diagnostic cost groups (DCGs) measure had the greatest predictive power overall and for the low- and high-cost subgroups, while the diabetes-specific measure had the lowest predictive power. A model with DCGs and the diabetes-specific measure modestly improved predictive power. CONCLUSIONS—Existing generic measures can be useful for diabetes-specific research and policy applications, but more predictive diabetes-specific measures are needed. PMID:18945927

Tamoxifen for breast cancer risk reduction: impact of alternative approaches to quality-of-life adjustment on cost-effectiveness analysis.

PubMed

Melnikow, Joy; Birch, Stephen; Slee, Christina; McCarthy, Theodore J; Helms, L Jay; Kuppermann, Miriam

2008-09-01

In cost-effectiveness analysis (CEA), the effects of health-care interventions on multiple health dimensions typically require consideration of both quantity and quality of life. To explore the impact of alternative approaches to quality-of-life adjustment using patient preferences (utilities) on the outcome of a CEA on use of tamoxifen for breast cancer risk reduction. A state transition Markov model tracked hypothetical cohorts of women who did or did not take 5 years of tamoxifen for breast cancer risk reduction. Incremental quality-adjusted effectiveness and cost-effectiveness ratios (ICERs) for models including and excluding a utility adjustment for menopausal symptoms were compared with each other and to a global utility model. Two hundred fifty-five women aged 50 and over with estimated 5-year breast cancer risk >or=1.67% participated in utility assessment interviews. Standard gamble utilities were assessed for specified tamoxifen-related health outcomes, current health, and for a global assessment of possible outcomes of tamoxifen use. Inclusion of a utility for menopausal symptoms in the outcome-specific models substantially increased the ICER; at the threshold 5-year breast cancer risk of 1.67%, tamoxifen was dominated. When a global utility for tamoxifen was used in place of outcome-specific utilities, tamoxifen was dominated under all circumstances. CEAs may be profoundly affected by the types of outcomes considered for quality-of-life adjustment and how these outcomes are grouped for utility assessment. Comparisons of ICERs across analyses must consider effects of different approaches to using utilities for quality-of-life adjustment.

Measurement and risk adjustment of prelabor cesarean rates in a large sample of California hospitals.

PubMed

Huesch, Marco D; Currid-Halkett, Elizabeth; Doctor, Jason N

2014-05-01

Prelabor cesareans in women without a prior cesarean is an important quality measure, yet one that is seldom tracked. We estimated patient-level risks and calculated how sensitive hospital rankings on this proposed quality metric were to risk adjustment. This retrospective cohort study linked Californian patient data from the Agency for Healthcare Research and Quality with hospital-level operational and financial data. Using the outcome of primary prelabor cesarean, we estimated patient-level logistic regressions in progressively more detailed models. We assessed incremental fit and discrimination, and aggregated the predicted patient-level event probabilities to construct hospital-level rankings. Of 408,355 deliveries by women without prior cesareans at 254 hospitals, 11.0% were prelabor cesareans. Including age, ethnicity, race, insurance, weekend and unscheduled admission, and 12 well-known patient risk factors yielded a model c-statistic of 0.83. Further maternal comorbidities, and hospital and obstetric unit characteristics only marginally improved fit. Risk adjusting hospital rankings led to a median absolute change in rank of 44 places compared to rankings based on observed rates. Of the 48 (49) hospitals identified as in the best (worst) quintile on observed rates, only 23 (18) were so identified by the risk-adjusted model. Models predict primary prelabor cesareans with good discrimination. Systematic hospital-level variation in patient risk factors requires risk adjustment to avoid considerably different classification of hospitals by outcome performance. An opportunity exists to define this metric and report such risk-adjusted outcomes to stakeholders. Copyright © 2014 Mosby, Inc. All rights reserved.

Permethrin Exposure Dosimetry: Biomarkers and Modifiable Factors

DTIC Science & Technology

2017-08-01

metabolite; (F = 16.16, p < 0.0001). This association holds after controlling for known confounders including sex , age, time that uniform was worn...and metabolite concentrations were examined via linear mixed modeling. All models were adjusted for creatinine, age, sex , days in BCT, number of

78 FR 75257 - Flutriafol; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-11

... for which there is reliable information.'' This includes exposure through drinking water and in...), modeled drinking water estimates, and DEEM\\TM\\ ver. 7.81 default processing factors. ii. Chronic exposure... residues adjusted to account for the residues of concern for risk assessment, 100 PCT, modeled drinking...

Association between maternal health literacy and child vaccination in India: a cross-sectional study

PubMed Central

Johri, Mira; Subramanian, S V; Sylvestre, Marie-Pierre; Dudeja, Sakshi; Chandra, Dinesh; Koné, Georges K; Sharma, Jitendar K; Pahwa, Smriti

2015-01-01

Background Education of mothers may improve child health. We investigated whether maternal health literacy, a rapidly modifiable factor related to mother's education, was associated with children's receipt of vaccines in two underserved Indian communities. Methods Cross-sectional surveys in an urban and a rural site. We assessed health literacy using Indian child health promotion materials. The outcome was receipt of three doses of diphtheria-tetanus-pertussis (DTP3) vaccine. We used multivariate logistic regression to investigate the relationship between maternal health literacy and vaccination status independently in each site. For both sites, adjusted models considered maternal age, maternal and paternal education, child sex, birth order, household religion and wealth quintile. Rural analyses used multilevel models adjusted for service delivery characteristics. Urban analyses represented cluster characteristics through fixed effects. Results The rural analysis included 1170 women from 60 villages. The urban analysis included 670 women from nine slum clusters. In each site, crude and adjusted models revealed a positive association between maternal health literacy and DTP3. In the rural site, the adjusted OR was 1.57 (95% CI 1.11 to 2.21, p=0.010) for those with medium health literacy, and OR=1.30 (95% CI 0.89 to 1.91, p=0.172) for those with high health literacy. In the urban site, the adjusted OR was 1.10 (95% CI 0.65 to 1.88, p=0.705) for those with medium health literacy, and OR=2.06 (95% CI 1.06 to 3.99, p=0.032) for those with high health literacy. Conclusions In these study settings, maternal health literacy is independently associated with child vaccination. Initiatives targeting health literacy could improve vaccination coverage. PMID:25827469

Shortwave radiative forcing, rapid adjustment, and feedback to the surface by sulfate geoengineering: analysis of the Geoengineering Model Intercomparison Project G4 scenario

DOE PAGES

Kashimura, Hiroki; Abe, Manabu; Watanabe, Shingo; ...

2017-03-08

This paper evaluates the forcing, rapid adjustment, and feedback of net shortwave radiation at the surface in the G4 experiment of the Geoengineering Model Intercomparison Project by analysing outputs from six participating models. G4 involves injection of 5 Tg yr -1 of SO 2, a sulfate aerosol precursor, into the lower stratosphere from year 2020 to 2069 against a background scenario of RCP4.5. A single-layer atmospheric model for shortwave radiative transfer is used to estimate the direct forcing of solar radiation management (SRM), and rapid adjustment and feedbacks from changes in the water vapour amount, cloud amount, and surface albedo (compared with RCP4.5). The analysismore » shows that the globally and temporally averaged SRM forcing ranges from -3.6 to -1.6 W m -2, depending on the model. The sum of the rapid adjustments and feedback effects due to changes in the water vapour and cloud amounts increase the downwelling shortwave radiation at the surface by approximately 0.4 to 1.5 W m -2 and hence weaken the effect of SRM by around 50 %. The surface albedo changes decrease the net shortwave radiation at the surface; it is locally strong (~-4 W m -2) in snow and sea ice melting regions, but minor for the global average. The analyses show that the results of the G4 experiment, which simulates sulfate geoengineering, include large inter-model variability both in the direct SRM forcing and the shortwave rapid adjustment from change in the cloud amount, and imply a high uncertainty in modelled processes of sulfate aerosols and clouds.« less

A comparison of administrative and physiologic predictive models in determining risk adjusted mortality rates in critically ill patients.

PubMed

Enfield, Kyle B; Schafer, Katherine; Zlupko, Mike; Herasevich, Vitaly; Novicoff, Wendy M; Gajic, Ognjen; Hoke, Tracey R; Truwit, Jonathon D

2012-01-01

Hospitals are increasingly compared based on clinical outcomes adjusted for severity of illness. Multiple methods exist to adjust for differences between patients. The challenge for consumers of this information, both the public and healthcare providers, is interpreting differences in risk adjustment models particularly when models differ in their use of administrative and physiologic data. We set to examine how administrative and physiologic models compare to each when applied to critically ill patients. We prospectively abstracted variables for a physiologic and administrative model of mortality from two intensive care units in the United States. Predicted mortality was compared through the Pearsons Product coefficient and Bland-Altman analysis. A subgroup of patients admitted directly from the emergency department was analyzed to remove potential confounding changes in condition prior to ICU admission. We included 556 patients from two academic medical centers in this analysis. The administrative model and physiologic models predicted mortalities for the combined cohort were 15.3% (95% CI 13.7%, 16.8%) and 24.6% (95% CI 22.7%, 26.5%) (t-test p-value<0.001). The r(2) for these models was 0.297. The Bland-Atlman plot suggests that at low predicted mortality there was good agreement; however, as mortality increased the models diverged. Similar results were found when analyzing a subgroup of patients admitted directly from the emergency department. When comparing the two hospitals, there was a statistical difference when using the administrative model but not the physiologic model. Unexplained mortality, defined as those patients who died who had a predicted mortality less than 10%, was a rare event by either model. In conclusion, while it has been shown that administrative models provide estimates of mortality that are similar to physiologic models in non-critically ill patients with pneumonia, our results suggest this finding can not be applied globally to patients admitted to intensive care units. As patients and providers increasingly use publicly reported information in making health care decisions and referrals, it is critical that the provided information be understood. Our results suggest that severity of illness may influence the mortality index in administrative models. We suggest that when interpreting "report cards" or metrics, health care providers determine how the risk adjustment was made and compares to other risk adjustment models.

Associations between different components of fitness and fatness with academic performance in Chilean youths.

PubMed

Olivares, Pedro R; García-Rubio, Javier

2016-01-01

To analyze the associations between different components of fitness and fatness with academic performance, adjusting the analysis by sex, age, socio-economic status, region and school type in a Chilean sample. Data of fitness, fatness and academic performance was obtained from the Chilean System for the Assessment of Educational Quality test for eighth grade in 2011 and includes a sample of 18,746 subjects (49% females). Partial correlations adjusted by confounders were done to explore association between fitness and fatness components, and between the academic scores. Three unadjusted and adjusted linear regression models were done in order to analyze the associations of variables. Fatness has a negative association with academic performance when Body Mass Index (BMI) and Waist to Height Ratio (WHR) are assessed independently. When BMI and WHR are assessed jointly and adjusted by cofounders, WHR is more associated with academic performance than BMI, and only the association of WHR is positive. For fitness components, strength was the variable most associated with the academic performance. Cardiorespiratory capacity was not associated with academic performance if fatness and other fitness components are included in the model. Fitness and fatness are associated with academic performance. WHR and strength are more related with academic performance than BMI and cardiorespiratory capacity.

Associations between different components of fitness and fatness with academic performance in Chilean youths

PubMed Central

2016-01-01

Objectives To analyze the associations between different components of fitness and fatness with academic performance, adjusting the analysis by sex, age, socio-economic status, region and school type in a Chilean sample. Methods Data of fitness, fatness and academic performance was obtained from the Chilean System for the Assessment of Educational Quality test for eighth grade in 2011 and includes a sample of 18,746 subjects (49% females). Partial correlations adjusted by confounders were done to explore association between fitness and fatness components, and between the academic scores. Three unadjusted and adjusted linear regression models were done in order to analyze the associations of variables. Results Fatness has a negative association with academic performance when Body Mass Index (BMI) and Waist to Height Ratio (WHR) are assessed independently. When BMI and WHR are assessed jointly and adjusted by cofounders, WHR is more associated with academic performance than BMI, and only the association of WHR is positive. For fitness components, strength was the variable most associated with the academic performance. Cardiorespiratory capacity was not associated with academic performance if fatness and other fitness components are included in the model. Conclusions Fitness and fatness are associated with academic performance. WHR and strength are more related with academic performance than BMI and cardiorespiratory capacity. PMID:27761345

MO-C-17A-04: Forecasting Longitudinal Changes in Oropharyngeal Tumor Morphology Throughout the Course of Head and Neck Radiation Therapy

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

Yock, A; UT Graduate School of Biomedical Sciences, Houston, TX; Rao, A

2014-06-15

Purpose: To generate, evaluate, and compare models that predict longitudinal changes in tumor morphology throughout the course of radiation therapy. Methods: Two morphology feature vectors were used to describe the size, shape, and position of 35 oropharyngeal GTVs at each treatment fraction during intensity-modulated radiation therapy. The feature vectors comprised the coordinates of the GTV centroids and one of two shape descriptors. One shape descriptor was based on radial distances between the GTV centroid and 614 GTV surface landmarks. The other was based on a spherical harmonic decomposition of these distances. Feature vectors over the course of therapy were describedmore » using static, linear, and mean models. The error of these models in forecasting GTV morphology was evaluated with leave-one-out cross-validation, and their accuracy was compared using Wilcoxon signed-rank tests. The effect of adjusting model parameters at 1, 2, 3, or 5 time points (adjustment points) was also evaluated. Results: The addition of a single adjustment point to the static model decreased the median error in forecasting the position of GTV surface landmarks by 1.2 mm (p<0.001). Additional adjustment points further decreased forecast error by about 0.4 mm each. The linear model decreased forecast error compared to the static model for feature vectors based on both shape descriptors (0.2 mm), while the mean model did so only for those based on the inter-landmark distances (0.2 mm). The decrease in forecast error due to adding adjustment points was greater than that due to model selection. Both effects diminished with subsequent adjustment points. Conclusion: Models of tumor morphology that include information from prior patients and/or prior treatment fractions are able to predict the tumor surface at each treatment fraction during radiation therapy. The predicted tumor morphology can be compared with patient anatomy or dose distributions, opening the possibility of anticipatory re-planning. American Legion Auxiliary Fellowship; The University of Texas Graduate School of Biomedical Sciences at Houston.« less

Direct comparison of risk-adjusted and non-risk-adjusted CUSUM analyses of coronary artery bypass surgery outcomes.

PubMed

Novick, Richard J; Fox, Stephanie A; Stitt, Larry W; Forbes, Thomas L; Steiner, Stefan

2006-08-01

We previously applied non-risk-adjusted cumulative sum methods to analyze coronary bypass outcomes. The objective of this study was to assess the incremental advantage of risk-adjusted cumulative sum methods in this setting. Prospective data were collected in 793 consecutive patients who underwent coronary bypass grafting performed by a single surgeon during a period of 5 years. The composite occurrence of an "adverse outcome" included mortality or any of 10 major complications. An institutional logistic regression model for adverse outcome was developed by using 2608 contemporaneous patients undergoing coronary bypass. The predicted risk of adverse outcome in each of the surgeon's 793 patients was then calculated. A risk-adjusted cumulative sum curve was then generated after specifying control limits and odds ratio. This risk-adjusted curve was compared with the non-risk-adjusted cumulative sum curve, and the clinical significance of this difference was assessed. The surgeon's adverse outcome rate was 96 of 793 (12.1%) versus 270 of 1815 (14.9%) for all the other institution's surgeons combined (P = .06). The non-risk-adjusted curve reached below the lower control limit, signifying excellent outcomes between cases 164 and 313, 323 and 407, and 667 and 793, but transgressed the upper limit between cases 461 and 478. The risk-adjusted cumulative sum curve never transgressed the upper control limit, signifying that cases preceding and including 461 to 478 were at an increased predicted risk. Furthermore, if the risk-adjusted cumulative sum curve was reset to zero whenever a control limit was reached, it still signaled a decrease in adverse outcome at 166, 653, and 782 cases. Risk-adjusted cumulative sum techniques provide incremental advantages over non-risk-adjusted methods by not signaling a decrement in performance when preoperative patient risk is high.

Childhood Epilepsy and Asthma: A Test of an Extension of the Double ABCX Model.

ERIC Educational Resources Information Center

Austin, Joan Kessner

The Double ABCX Model of Family Adjustment and Adaptation, a model that predicts adaptation to chronic stressors on the family, was extended by dividing it into attitudes, coping, and adaptation of parents and child separately, and by including variables relevant to child adaptation to epilepsy or asthma. The extended model was tested on 246…

Development of mathematical models of environmental physiology

NASA Technical Reports Server (NTRS)

Stolwijk, J. A. J.; Mitchell, J. W.; Nadel, E. R.

1971-01-01

Selected articles concerned with mathematical or simulation models of human thermoregulation are presented. The articles presented include: (1) development and use of simulation models in medicine, (2) model of cardio-vascular adjustments during exercise, (3) effective temperature scale based on simple model of human physiological regulatory response, (4) behavioral approach to thermoregulatory set point during exercise, and (5) importance of skin temperature in sweat regulation.

Spherical Model Integrating Academic Competence with Social Adjustment and Psychopathology.

ERIC Educational Resources Information Center

Schaefer, Earl S.; And Others

This study replicates and elaborates a three-dimensional, spherical model that integrates research findings concerning social and emotional behavior, psychopathology, and academic competence. Kindergarten teachers completed an extensive set of rating scales on 100 children, including the Classroom Behavior Inventory and the Child Adaptive Behavior…

Novice drivers' risky driving behavior, risk perception, and crash risk: findings from the DRIVE study.

PubMed

Ivers, Rebecca; Senserrick, Teresa; Boufous, Soufiane; Stevenson, Mark; Chen, Huei-Yang; Woodward, Mark; Norton, Robyn

2009-09-01

We explored the risky driving behaviors and risk perceptions of a cohort of young novice drivers and sought to determine their associations with crash risk. Provisional drivers aged 17 to 24 (n = 20 822) completed a detailed questionnaire that included measures of risk perception and behaviors; 2 years following recruitment, survey data were linked to licensing and police-reported crash data. Poisson regression models that adjusted for multiple confounders were created to explore crash risk. High scores on questionnaire items for risky driving were associated with a 50% increased crash risk (adjusted relative risk = 1.51; 95% confidence interval = 1.25, 1.81). High scores for risk perception (poorer perceptions of safety) were also associated with increased crash risk in univariate and multivariate models; however, significance was not sustained after adjustment for risky driving. The overrepresentation of youths in crashes involving casualties is a significant public health issue. Risky driving behavior is strongly linked to crash risk among young drivers and overrides the importance of risk perceptions. Systemwide intervention, including licensing reform, is warranted.

Political violence and child adjustment in Northern Ireland: Testing pathways in a social-ecological model including single-and two-parent families.

PubMed

Cummings, E Mark; Schermerhorn, Alice C; Merrilees, Christine E; Goeke-Morey, Marcie C; Shirlow, Peter; Cairns, Ed

2010-07-01

Moving beyond simply documenting that political violence negatively impacts children, we tested a social-ecological hypothesis for relations between political violence and child outcomes. Participants were 700 mother-child (M = 12.1 years, SD = 1.8) dyads from 18 working-class, socially deprived areas in Belfast, Northern Ireland, including single- and two-parent families. Sectarian community violence was associated with elevated family conflict and children's reduced security about multiple aspects of their social environment (i.e., family, parent-child relations, and community), with links to child adjustment problems and reductions in prosocial behavior. By comparison, and consistent with expectations, links with negative family processes, child regulatory problems, and child outcomes were less consistent for nonsectarian community violence. Support was found for a social-ecological model for relations between political violence and child outcomes among both single- and two-parent families, with evidence that emotional security and adjustment problems were more negatively affected in single-parent families. The implications for understanding social ecologies of political violence and children's functioning are discussed.

Political violence and child adjustment in Northern Ireland: Testing pathways in a social ecological model including single and two-parent families

PubMed Central

Cummings, E. Mark; Schermerhorn, Alice C.; Merrilees, Christine E.; Goeke-Morey, Marcie C.; Shirlow, Peter; Cairns, Ed

2013-01-01

Moving beyond simply documenting that political violence negatively impacts children, a social ecological hypothesis for relations between political violence and child outcomes was tested. Participants were 700 mother-child (M=12.1years, SD=1.8) dyads from 18 working class, socially deprived areas in Belfast, Northern Ireland, including single- and two-parent families. Sectarian community violence was associated with elevated family conflict and children’s reduced security about multiple aspects of their social environment (i.e., family, parent-child relations, and community), with links to child adjustment problems and reductions in prosocial behavior. By comparison, and consistent with expectations, links with negative family processes, child regulatory problems and child outcomes were less consistent for nonsectarian community violence. Support was found for a social ecological model for relations between political violence and child outcomes among both single and two parent families, with evidence that emotional security and adjustment problems were more negatively affected in single-parent families. The implications for understanding social ecologies of political violence and children’s functioning are discussed. PMID:20604605

Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century

USGS Publications Warehouse

Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

2013-01-01

The general progression of human land use is an initial disturbance (e.g., deforestation, mining, agricultural expansion, overgrazing, and urbanization) that creates a sediment pulse to an estuary followed by dams that reduce sediment supply. We present a conceptual model of the effects of increasing followed by decreasing sediment supply that includes four sequential regimes, which propagate downstream: a stationary natural regime, transient increasing sediment supply, transient decreasing sediment supply, and a stationary altered regime. The model features characteristic lines that separate the four regimes. Previous studies of the San Francisco Estuary and watershed are synthesized in the context of this conceptual model. Hydraulic mining for gold in the watershed increased sediment supply to the estuary in the late 1800s. Adjustment to decreasing sediment supply began in the watershed and upper estuary around 1900 and in the lower estuary in the 1950s. Large freshwater flow in the late 1990s caused a step adjustment throughout the estuary and watershed. It is likely that the estuary and watershed are still capable of adjusting but further adjustment will be as steps that occur only during greater floods than previously experienced during the adjustment period. Humans are actively managing the system to try to prevent greater floods. If this hypothesis of step changes occurring for larger flows is true, then the return interval of step changes will increase or, if humans successfully control floods in perpetuity, there will be no more step changes.

Victimization and perpetration of intimate partner violence and substance use disorders in a nationally representative sample.

PubMed

Afifi, Tracie O; Henriksen, Christine A; Asmundson, Gordon J G; Sareen, Jitender

2012-08-01

The aim of this study was to examine the relationship between perpetration and victimization of physical and sexual intimate partner violence (IPV) in the past year and substance use disorders (SUDs) in the past year, including alcohol, sedatives/tranquilizers, cocaine, cannabis, and nicotine stratified according to sex. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions. A series of adjusted logistic regression models were conducted. Among men and women, all types of SUDs were associated with increased odds of IPV perpetration (odds ranging from 1.4 to 8.5 adjusting for sociodemographic variables). IPV victimization increased the odds of having all types of SUDs for male and female victims, with the exception of sedatives/tranquilizer abuse/dependence among women (odds ranging from 1.5 to 6.0 adjusting for sociodemographic variables). Substances that had the most robust relationship with perpetration and victimization of IPV included alcohol and cannabis, after adjusting for sociodemographic variables, mood disorders, anxiety disorders, personality disorders, and mutual violence.

A case-mix classification system for explaining healthcare costs using administrative data in Italy.

PubMed

Corti, Maria Chiara; Avossa, Francesco; Schievano, Elena; Gallina, Pietro; Ferroni, Eliana; Alba, Natalia; Dotto, Matilde; Basso, Cristina; Netti, Silvia Tiozzo; Fedeli, Ugo; Mantoan, Domenico

2018-03-04

The Italian National Health Service (NHS) provides universal coverage to all citizens, granting primary and hospital care with a copayment system for outpatient and drug services. Financing of Local Health Trusts (LHTs) is based on a capitation system adjusted only for age, gender and area of residence. We applied a risk-adjustment system (Johns Hopkins Adjusted Clinical Groups System, ACG® System) in order to explain health care costs using routinely collected administrative data in the Veneto Region (North-eastern Italy). All residents in the Veneto Region were included in the study. The ACG system was applied to classify the regional population based on the following information sources for the year 2015: Hospital Discharges, Emergency Room visits, Chronic disease registry for copayment exemptions, ambulatory visits, medications, the Home care database, and drug prescriptions. Simple linear regressions were used to contrast an age-gender model to models incorporating more comprehensive risk measures aimed at predicting health care costs. A simple age-gender model explained only 8% of the variance of 2015 total costs. Adding diagnoses-related variables provided a 23% increase, while pharmacy based variables provided an additional 17% increase in explained variance. The adjusted R-squared of the comprehensive model was 6 times that of the simple age-gender model. ACG System provides substantial improvement in predicting health care costs when compared to simple age-gender adjustments. Aging itself is not the main determinant of the increase of health care costs, which is better explained by the accumulation of chronic conditions and the resulting multimorbidity. Copyright © 2018. Published by Elsevier B.V.

The Pennsylvania Trauma Outcomes Study Risk-Adjusted Mortality Model: Results of a Statewide Benchmarking Program

PubMed Central

WIEBE, DOUGLAS J.; HOLENA, DANIEL N.; DELGADO, M. KIT; McWILLIAMS, NATHAN; ALTENBURG, JULIET; CARR, BRENDAN G.

2018-01-01

Trauma centers need objective feedback on performance to inform quality improvement efforts. The Trauma Quality Improvement Program recently published recommended methodology for case mix adjustment and benchmarking performance. We tested the feasibility of applying this methodology to develop risk-adjusted mortality models for a statewide trauma system. We performed a retrospective cohort study of patients ≥16 years old at Pennsylvania trauma centers from 2011 to 2013 (n = 100,278). Our main outcome measure was observed-to-expected mortality ratios (overall and within blunt, penetrating, multisystem, isolated head, and geriatric subgroups). Patient demographic variables, physiology, mechanism of injury, transfer status, injury severity, and pre-existing conditions were included as predictor variables. The statistical model had excellent discrimination (area under the curve = 0.94). Funnel plots of observed-to-expected identified five centers with lower than expected mortality and two centers with higher than expected mortality. No centers were outliers for management of penetrating trauma, but five centers had lower and three had higher than expected mortality for blunt trauma. It is feasible to use Trauma Quality Improvement Program methodology to develop risk-adjusted models for statewide trauma systems. Even with smaller numbers of trauma centers that are available in national datasets, it is possible to identify high and low outliers in performance. PMID:28541852

The Pennsylvania Trauma Outcomes Study Risk-Adjusted Mortality Model: Results of a Statewide Benchmarking Program.

PubMed

Wiebe, Douglas J; Holena, Daniel N; Delgado, M Kit; McWilliams, Nathan; Altenburg, Juliet; Carr, Brendan G

2017-05-01

Trauma centers need objective feedback on performance to inform quality improvement efforts. The Trauma Quality Improvement Program recently published recommended methodology for case mix adjustment and benchmarking performance. We tested the feasibility of applying this methodology to develop risk-adjusted mortality models for a statewide trauma system. We performed a retrospective cohort study of patients ≥16 years old at Pennsylvania trauma centers from 2011 to 2013 (n = 100,278). Our main outcome measure was observed-to-expected mortality ratios (overall and within blunt, penetrating, multisystem, isolated head, and geriatric subgroups). Patient demographic variables, physiology, mechanism of injury, transfer status, injury severity, and pre-existing conditions were included as predictor variables. The statistical model had excellent discrimination (area under the curve = 0.94). Funnel plots of observed-to-expected identified five centers with lower than expected mortality and two centers with higher than expected mortality. No centers were outliers for management of penetrating trauma, but five centers had lower and three had higher than expected mortality for blunt trauma. It is feasible to use Trauma Quality Improvement Program methodology to develop risk-adjusted models for statewide trauma systems. Even with smaller numbers of trauma centers that are available in national datasets, it is possible to identify high and low outliers in performance.

Scale-up on basis of structured mixing models: A new concept.

PubMed

Mayr, B; Moser, A; Nagy, E; Horvat, P

1994-02-05

A new scale-up concept based upon mixing models for bioreactors equipped with Rushton turbines using the tanks-in-series concept is presented. The physical mixing model includes four adjustable parameters, i.e., radial and axial circulation time, number of ideally mixed elements in one cascade, and the volume of the ideally mixed turbine region. The values of the model parameters were adjusted with the application of a modified Monte-Carlo optimization method, which fitted the simulated response function to the experimental curve. The number of cascade elements turned out to be constant (N = 4). The model parameter radial circulation time is in good agreement with the one obtained by the pumping capacity. In case of remaining parameters a first or second order formal equation was developed, including four operational parameters (stirring and aeration intensity, scale, viscosity). This concept can be extended to several other types of bioreactors as well, and it seems to be a suitable tool to compare the bioprocess performance of different types of bioreactors. (c) 1994 John Wiley & Sons, Inc.

Predicting the Effects of Water Quality on the Growth of Thalassia testudinum in Tampa Bay with a Dynamic Simile-Based Model Tool

EPA Science Inventory

We describe a seagrass growth (SGG) model that is coupled to a water quality (WQ) model that includes the effects of phytoplankton (chlorophyll), colored dissolved organic matter (CDOM) and suspended solids (TSS) on water clarity. Phytoplankton growth was adjusted daily for PAR (...

Problems with Current Models of Grieving and Consequences for Older Persons.

ERIC Educational Resources Information Center

Horacek, Bruce J.

Classical models of the grieving process include Freud's concept of withdrawal of ties to the love object called decathexis, and Lindemann's emancipation from the bondage to the deceased involving adjusting to the loss in one's environment and the ability to form new relationships. Most of the models and explanations of the grieving process over…

Assessing Psychological Symptoms and Well-Being: Application of a Dual-Factor Mental Health Model to Understand College Student Performance

ERIC Educational Resources Information Center

Antaramian, Susan

2015-01-01

A dual-factor mental health model includes measures of positive psychological well-being in addition to traditional indicators of psychopathology to comprehensively determine mental health status. The current study examined the utility of this model in understanding the psychological adjustment and educational functioning of college students. A…

A physically-based channel-modeling framework integrating HEC-RAS sediment transport capabilities and the USDA-ARS bank-stability and toe-erosion model (BSTEM)

USDA-ARS?s Scientific Manuscript database

Classical, one-dimensional, mobile bed, sediment-transport models simulate vertical channel adjustment, raising or lowering cross-section node elevations to simulate erosion or deposition. This approach does not account for bank erosion processes including toe scour and mass failure. In many systems...

Parental dysphoria and children's adjustment: marital conflict styles, children's emotional security, and parenting as mediators of risk.

PubMed

Du Rocher Schudlich, Tina D; Cummings, E Mark

2007-08-01

Dimensions of martial conflict, children's emotional security regarding interparental conflict, and parenting style were examined as mediators between parental dysphoria and child adjustment. A community sample of 262 children, ages 8-16, participated with their parents. Behavioral observations were made of parents' interactions during marital conflict resolution tasks, which children later observed to assess their emotional security. Questionnaires assessed parents' dysphoria, parenting, and children's adjustment. Structural equation modeling indicated that parental dysphoria was linked with child adjustment through specific and distinct mediating family processes, including marital conflict and parenting. Children's emotional security in the context of particular marital conflict styles also mediated relations between parental dysphoria and child adjustment problems, with similar pathways found for mothers and fathers. These pathways remained significant even after significant parenting contributions were considered.

A High-Resolution Integrated Model of the National Ignition Campaign Cryogenic Layered Experiments

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

Jones, O. S.; Callahan, D. A.; Cerjan, C. J.

A detailed simulation-based model of the June 2011 National Ignition Campaign (NIC) cryogenic DT experiments is presented. The model is based on integrated hohlraum-capsule simulations that utilize the best available models for the hohlraum wall, ablator, and DT equations of state and opacities. The calculated radiation drive was adjusted by changing the input laser power to match the experimentally measured shock speeds, shock merger times, peak implosion velocity, and bangtime. The crossbeam energy transfer model was tuned to match the measured time-dependent symmetry. Mid-mode mix was included by directly modeling the ablator and ice surface perturbations up to mode 60.more » Simulated experimental values were extracted from the simulation and compared against the experiment. The model adjustments brought much of the simulated data into closer agreement with the experiment, with the notable exception of the measured yields, which were 15-40% of the calculated yields.« less

A High-Resolution Integrated Model of the National Ignition Campaign Cryogenic Layered Experiments

DOE PAGES

Jones, O. S.; Callahan, D. A.; Cerjan, C. J.; ...

2012-05-29

A detailed simulation-based model of the June 2011 National Ignition Campaign (NIC) cryogenic DT experiments is presented. The model is based on integrated hohlraum-capsule simulations that utilize the best available models for the hohlraum wall, ablator, and DT equations of state and opacities. The calculated radiation drive was adjusted by changing the input laser power to match the experimentally measured shock speeds, shock merger times, peak implosion velocity, and bangtime. The crossbeam energy transfer model was tuned to match the measured time-dependent symmetry. Mid-mode mix was included by directly modeling the ablator and ice surface perturbations up to mode 60.more » Simulated experimental values were extracted from the simulation and compared against the experiment. The model adjustments brought much of the simulated data into closer agreement with the experiment, with the notable exception of the measured yields, which were 15-40% of the calculated yields.« less

Towards an Integrated Model of the NIC Layered Implosions

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

Jones, O S; Callahan, D A; Cerjan, C J

A detailed simulation-based model of the June 2011 National Ignition Campaign (NIC) cryogenic DT experiments is presented. The model is based on integrated hohlraum-capsule simulations that utilize the best available models for the hohlraum wall, ablator, and DT equations of state and opacities. The calculated radiation drive was adjusted by changing the input laser power to match the experimentally measured shock speeds, shock merger times, peak implosion velocity, and bangtime. The crossbeam energy transfer model was tuned to match the measured time-dependent symmetry. Mid-mode mix was included by directly modeling the ablator and ice surface perturbations up to mode 60.more » Simulated experimental values were extracted from the simulation and compared against the experiment. The model adjustments brought much of the simulated data into closer agreement with the experiment, with the notable exception of the measured yields, which were 15-45% of the calculated yields.« less

Further SEASAT SAR coastal ocean wave analysis

NASA Technical Reports Server (NTRS)

Kasischke, E. S.; Shuchman, R. A.; Meadows, G. A.; Jackson, P. L.; Tseng, Y.

1981-01-01

Analysis techniques used to exploit SEASAT synthetic aperture radar (SAR) data of gravity waves are discussed and the SEASAT SAR's ability to monitor large scale variations in gravity wave fields in both deep and shallow water is evaluated. The SAR analysis techniques investigated included motion compensation adjustments and the semicausal model for spectral analysis of SAR wave data. It was determined that spectra generated from fast Fourier transform analysis (FFT) of SAR wave data were not significantly altered when either range telerotation adjustments or azimuth focus shifts were used during processing of the SAR signal histories, indicating that SEASAT imagery of gravity waves is not significantly improved or degraded by motion compensation adjustments. Evaluation of the semicausal (SC) model using SEASAT SAR data from Rev. 974 indicates that the SC spectral estimates were not significantly better than the FFT results.

Pancreatic β-Cell Function and Prognosis of Nondiabetic Patients With Ischemic Stroke.

PubMed

Pan, Yuesong; Chen, Weiqi; Jing, Jing; Zheng, Huaguang; Jia, Qian; Li, Hao; Zhao, Xingquan; Liu, Liping; Wang, Yongjun; He, Yan; Wang, Yilong

2017-11-01

Pancreatic β-cell dysfunction is an important factor in the development of type 2 diabetes mellitus. This study aimed to estimate the association between β-cell dysfunction and prognosis of nondiabetic patients with ischemic stroke. Patients with ischemic stroke without a history of diabetes mellitus in the ACROSS-China (Abnormal Glucose Regulation in Patients with Acute Stroke across China) registry were included. Disposition index was estimated as computer-based model of homeostatic model assessment 2-β%/homeostatic model assessment 2-insulin resistance based on fasting C-peptide level. Outcomes included stroke recurrence, all-cause death, and dependency (modified Rankin Scale, 3-5) at 12 months after onset. Among 1171 patients, 37.2% were women with a mean age of 62.4 years. At 12 months, 167 (14.8%) patients had recurrent stroke, 110 (9.4%) died, and 184 (16.0%) had a dependency. The first quartile of the disposition index was associated with an increased risk of stroke recurrence (adjusted hazard ratio, 3.57; 95% confidence interval, 2.13-5.99) and dependency (adjusted hazard ratio, 2.30; 95% confidence interval, 1.21-4.38); both the first and second quartiles of the disposition index were associated with an increased risk of death (adjusted hazard ratio, 5.09; 95% confidence interval, 2.51-10.33; adjusted hazard ratio, 2.42; 95% confidence interval, 1.17-5.03) compared with the fourth quartile. Using a multivariable regression model with restricted cubic spline, we observed an L-shaped association between the disposition index and the risk of each end point. In this large-scale registry, β-cell dysfunction was associated with an increased risk of 12-month poor prognosis in nondiabetic patients with ischemic stroke. © 2017 American Heart Association, Inc.

Macro-level gender equality and alcohol consumption: A multi-level analysis across U.S. States

PubMed Central

Roberts, Sarah C.M.

2014-01-01

Higher levels of women’s alcohol consumption have long been attributed to increases in gender equality. However, only limited research examines the relationship between gender equality and alcohol consumption. This study examined associations between five measures of state-level gender equality and five alcohol consumption measures in the United States. Survey data regarding men’s and women’s alcohol consumption from the 2005 Behavioral Risk Factor Surveillance System were linked to state-level indicators of gender equality. Gender equality indicators included state-level women’s socioeconomic status, gender equality in socioeconomic status, reproductive rights, policies relating to violence against women, and women’s political participation. Alcohol consumption measures included past 30-day drinker status, drinking frequency, binge drinking, volume, and risky drinking. Other than drinker status, consumption is measured for drinkers only. Multi-level linear and logistic regression models adjusted for individual demographics as well as state-level income inequality, median income, and % Evangelical Protestant/Mormon. All gender equality indicators were positively associated with both women’s and men’s drinker status in models adjusting only for individual-level covariates; associations were not significant in models adjusting for other state-level characteristics. All other associations between gender equality and alcohol consumption were either negative or non-significant for both women and men in models adjusting for other state-level factors. Findings do not support the hypothesis that higher levels of gender equality are associated with higher levels of alcohol consumption by women or by men. In fact, most significant findings suggest that higher levels of equality are associated with less alcohol consumption overall. PMID:22521679

Case-mix adjustment of consumer reports about managed behavioral health care and health plans.

PubMed

Eselius, Laura L; Cleary, Paul D; Zaslavsky, Alan M; Huskamp, Haiden A; Busch, Susan H

2008-12-01

To develop a model for adjusting patients' reports of behavioral health care experiences on the Experience of Care and Health Outcomes (ECHO) survey to allow for fair comparisons across health plans. Survey responses from 4,068 individuals enrolled in 21 managed behavioral health plans who received behavioral health care within the previous year (response rate = 48 percent). Potential case-mix adjustors were evaluated by combining information about their predictive power and the amount of within- and between-plan variability. Changes in plan scores and rankings due to case-mix adjustment were quantified. The final case-mix adjustment model included self-reported mental health status, self-reported general health status, alcohol/drug treatment, age, education, and race/ethnicity. The impact of adjustment on plan report scores was modest, but large enough to change some plan rankings. Adjusting plan report scores on the ECHO survey for differences in patient characteristics had modest effects, but still may be important to maintain the credibility of patient reports as a quality metric. Differences between those with self-reported fair/poor health compared with those in excellent/very good health varied by plan, suggesting quality differences associated with health status and underscoring the importance of collecting quality information.

When does female multiple mating evolve to adjust inbreeding? Effects of inbreeding depression, direct costs, mating constraints, and polyandry as a threshold trait

PubMed Central

Duthie, A. Bradley; Bocedi, Greta; Reid, Jane M.

2016-01-01

Polyandry is often hypothesized to evolve to allow females to adjust the degree to which they inbreed. Multiple factors might affect such evolution, including inbreeding depression, direct costs, constraints on male availability, and the nature of polyandry as a threshold trait. Complex models are required to evaluate when evolution of polyandry to adjust inbreeding is predicted to arise. We used a genetically explicit individual‐based model to track the joint evolution of inbreeding strategy and polyandry defined as a polygenic threshold trait. Evolution of polyandry to avoid inbreeding only occurred given strong inbreeding depression, low direct costs, and severe restrictions on initial versus additional male availability. Evolution of polyandry to prefer inbreeding only occurred given zero inbreeding depression and direct costs, and given similarly severe restrictions on male availability. However, due to its threshold nature, phenotypic polyandry was frequently expressed even when strongly selected against and hence maladaptive. Further, the degree to which females adjusted inbreeding through polyandry was typically very small, and often reflected constraints on male availability rather than adaptive reproductive strategy. Evolution of polyandry solely to adjust inbreeding might consequently be highly restricted in nature, and such evolution cannot necessarily be directly inferred from observed magnitudes of inbreeding adjustment. PMID:27464756

Neighborhood Contexts, Fathers, and Mexican American Young Adolescents' Internalizing Symptoms

ERIC Educational Resources Information Center

White, Rebecca M. B.; Roosa, Mark W.

2012-01-01

The family stress model posits that contextual stressors, such as neighborhood danger, negatively influence youth adjustment, including internalizing symptoms, via disruptions in parenting and family processes. The current study examined a culturally and contextually modified family stress model in a diverse sample of Mexican-origin fathers and…

Social support and substitute voice acquisition on psychological adjustment among patients after laryngectomy.

PubMed

Kotake, Kumiko; Suzukamo, Yoshimi; Kai, Ichiro; Iwanaga, Kazuyo; Takahashi, Aya

2017-03-01

The objective is to clarify whether social support and acquisition of alternative voice enhance the psychological adjustment of laryngectomized patients and which part of the psychological adjustment structure would be influenced by social support. We contacted 1445 patients enrolled in a patient association using mail surveys and 679 patients agreed to participate in the study. The survey items included age, sex, occupation, post-surgery duration, communication method, psychological adjustment (by the Nottingham Adjustment Scale Japanese Laryngectomy Version: NAS-J-L), and the formal support (by Hospital Patient Satisfaction Questionnaire-25: HPSQ-25). Social support and communication methods were added to the three-tier structural model of psychological adjustment shown in our previous study, and a covariance structure analysis was conducted. Formal/informal supports and acquisition of alternative voice influence only the "recognition of oneself as voluntary agent", the first tier of the three-tier structure of psychological adjustment. The results suggest that social support and acquisition of alternative voice may enhance the recognition of oneself as voluntary agent and promote the psychological adjustment.

Autonomy, belongingness, and engagement in school as contributors to adolescent psychological well-being.

PubMed

Van Ryzin, Mark J; Gravely, Amy A; Roseth, Cary J

2009-01-01

Self-determination theory emphasizes the importance of school-based autonomy and belongingness to academic achievement and psychological adjustment, and the theory posits a model in which engagement in school mediates the influence of autonomy and belongingness on these outcomes. To date, this model has only been evaluated on academic outcomes. Utilizing short-term longitudinal data (5-month timeframe) from a set of secondary schools in the rural Midwest (N = 283, M age = 15.3, 51.9% male, 86.2% White), we extend the model to include a measure of positive adjustment (i.e., hope). We also find a direct link between peer-related belongingness (i.e., peer support) and positive adjustment that is not mediated by engagement in school. A reciprocal relationship between academic autonomy, teacher-related belongingness (i.e., teacher support) and engagement in learning is supported, but this reciprocal relationship does not extend to peer-related belongingness. The implications of these findings for secondary schools are discussed.

Factors influencing psychosocial adjustment and quality of life in Parkinson patients and informal caregivers.

PubMed

Navarta-Sánchez, María Victoria; Senosiain García, Juana M; Riverol, Mario; Ursúa Sesma, María Eugenia; Díaz de Cerio Ayesa, Sara; Anaut Bravo, Sagrario; Caparrós Civera, Neus; Portillo, Mari Carmen

2016-08-01

The influence that social conditions and personal attitudes may have on the quality of life (QoL) of Parkinson's disease (PD) patients and informal caregivers does not receive enough attention in health care, as a result of it not being clearly identified, especially in informal caregivers. The aim of this study was to provide a comprehensive analysis of psychosocial adjustment and QoL determinants in PD patients and informal caregivers. Ninety-one PD patients and 83 caregivers participated in the study. Multiple regression analyses were performed including benefit finding, coping, disease severity and socio-demographic factors, in order to determine how these aspects influence the psychosocial adjustment and QoL in PD patients and caregivers. Regression models showed that severity of PD was the main predictor of psychosocial adjustment and QoL in patients. Nevertheless, multiple regression analyses also revealed that coping was a significant predictor of psychosocial adjustment in patients and caregivers. Furthermore, psychosocial adjustment was significantly related to QoL in patients and caregivers. Also, coping and benefit finding were predictors of QoL in caregivers but not in patients. Multidisciplinary interventions aimed at improving PD patients' QoL may have more effective outcomes if education about coping skills, and how these can help towards a positive psychosocial adjustment to illness, were included, and targeted not only at patients, but also at informal caregivers.

Environmental Chemicals in Urine and Blood: Improving Methods for Creatinine and Lipid Adjustment.

PubMed

O'Brien, Katie M; Upson, Kristen; Cook, Nancy R; Weinberg, Clarice R

2016-02-01

Investigators measuring exposure biomarkers in urine typically adjust for creatinine to account for dilution-dependent sample variation in urine concentrations. Similarly, it is standard to adjust for serum lipids when measuring lipophilic chemicals in serum. However, there is controversy regarding the best approach, and existing methods may not effectively correct for measurement error. We compared adjustment methods, including novel approaches, using simulated case-control data. Using a directed acyclic graph framework, we defined six causal scenarios for epidemiologic studies of environmental chemicals measured in urine or serum. The scenarios include variables known to influence creatinine (e.g., age and hydration) or serum lipid levels (e.g., body mass index and recent fat intake). Over a range of true effect sizes, we analyzed each scenario using seven adjustment approaches and estimated the corresponding bias and confidence interval coverage across 1,000 simulated studies. For urinary biomarker measurements, our novel method, which incorporates both covariate-adjusted standardization and the inclusion of creatinine as a covariate in the regression model, had low bias and possessed 95% confidence interval coverage of nearly 95% for most simulated scenarios. For serum biomarker measurements, a similar approach involving standardization plus serum lipid level adjustment generally performed well. To control measurement error bias caused by variations in serum lipids or by urinary diluteness, we recommend improved methods for standardizing exposure concentrations across individuals.

Can statistic adjustment of OR minimize the potential confounding bias for meta-analysis of case-control study? A secondary data analysis.

PubMed

Liu, Tianyi; Nie, Xiaolu; Wu, Zehao; Zhang, Ying; Feng, Guoshuang; Cai, Siyu; Lv, Yaqi; Peng, Xiaoxia

2017-12-29

Different confounder adjustment strategies were used to estimate odds ratios (ORs) in case-control study, i.e. how many confounders original studies adjusted and what the variables are. This secondary data analysis is aimed to detect whether there are potential biases caused by difference of confounding factor adjustment strategies in case-control study, and whether such bias would impact the summary effect size of meta-analysis. We included all meta-analyses that focused on the association between breast cancer and passive smoking among non-smoking women, as well as each original case-control studies included in these meta-analyses. The relative deviations (RDs) of each original study were calculated to detect how magnitude the adjustment would impact the estimation of ORs, compared with crude ORs. At the same time, a scatter diagram was sketched to describe the distribution of adjusted ORs with different number of adjusted confounders. Substantial inconsistency existed in meta-analysis of case-control studies, which would influence the precision of the summary effect size. First, mixed unadjusted and adjusted ORs were used to combine individual OR in majority of meta-analysis. Second, original studies with different adjustment strategies of confounders were combined, i.e. the number of adjusted confounders and different factors being adjusted in each original study. Third, adjustment did not make the effect size of original studies trend to constringency, which suggested that model fitting might have failed to correct the systematic error caused by confounding. The heterogeneity of confounder adjustment strategies in case-control studies may lead to further bias for summary effect size in meta-analyses, especially for weak or medium associations so that the direction of causal inference would be even reversed. Therefore, further methodological researches are needed, referring to the assessment of confounder adjustment strategies, as well as how to take this kind of bias into consideration when drawing conclusion based on summary estimation of meta-analyses.

Model verification of large structural systems

NASA Technical Reports Server (NTRS)

Lee, L. T.; Hasselman, T. K.

1977-01-01

A methodology was formulated, and a general computer code implemented for processing sinusoidal vibration test data to simultaneously make adjustments to a prior mathematical model of a large structural system, and resolve measured response data to obtain a set of orthogonal modes representative of the test model. The derivation of estimator equations is shown along with example problems. A method for improving the prior analytic model is included.

46 CFR 164.019-7 - Non-standard components; acceptance criteria and procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Inner Envelope Fabric; (iv) Closure (including zippers) or Adjustment Hardware; (v) Body Strap; (vi... in detail and including the unique style, part, or model number, the identification data required by the applicable subpart of this part, and any other manufacturer's identifying data. No two components...

46 CFR 164.019-7 - Non-standard components; acceptance criteria and procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Inner Envelope Fabric; (iv) Closure (including zippers) or Adjustment Hardware; (v) Body Strap; (vi... in detail and including the unique style, part, or model number, the identification data required by the applicable subpart of this part, and any other manufacturer's identifying data. No two components...

46 CFR 164.019-7 - Non-standard components; acceptance criteria and procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Inner Envelope Fabric; (iv) Closure (including zippers) or Adjustment Hardware; (v) Body Strap; (vi... in detail and including the unique style, part, or model number, the identification data required by the applicable subpart of this part, and any other manufacturer's identifying data. No two components...

Assessment of the value of repeated point-prevalence surveys for analyzing the trend in nosocomial infections.

PubMed

Sartor, Catherine; Delchambre, Anne; Pascal, Laurence; Drancourt, Michel; De Micco, Philippe; Sambuc, Roland

2005-04-01

To assess the value of repeated point-prevalence surveys in measuring the trend in nosocomial infections after adjustment for case mix. A 3,500-bed teaching facility composed of 4 acute care hospitals. From May 1992 to June 1996, eight point-prevalence surveys of nosocomial infections were performed in the hospitals using a sampling process. The trend of adjusted nosocomial infection rates was studied for the four surveys that collected data on indwelling catheters. Adjusted rates were calculated using a logistic regression model and a direct standardization method. From 1992 to 1996, a total of 20,238 patients were included in the 8 point-prevalence surveys. The nosocomial infection rate decreased from 8.6% in 1992 to 5% in 1996 (P < .001). The analysis of adjusted nosocomial infection rates included 9,600 patients. Four independent risk factors were identified: length of stay greater than 12 days, hospitalization in an intensive care unit, presence of an indwelling urinary catheter, and history of a surgical procedure. After adjustment for case mix, the nosocomial infection rate still showed a downward trend (from 7.2% in 1993 to 5.1% in 1996; P = .02). Adjusted prevalence rates of nosocomial infections showed a significant downward trend during the period of this study.

Double-adjustment in propensity score matching analysis: choosing a threshold for considering residual imbalance.

PubMed

Nguyen, Tri-Long; Collins, Gary S; Spence, Jessica; Daurès, Jean-Pierre; Devereaux, P J; Landais, Paul; Le Manach, Yannick

2017-04-28

Double-adjustment can be used to remove confounding if imbalance exists after propensity score (PS) matching. However, it is not always possible to include all covariates in adjustment. We aimed to find the optimal imbalance threshold for entering covariates into regression. We conducted a series of Monte Carlo simulations on virtual populations of 5,000 subjects. We performed PS 1:1 nearest-neighbor matching on each sample. We calculated standardized mean differences across groups to detect any remaining imbalance in the matched samples. We examined 25 thresholds (from 0.01 to 0.25, stepwise 0.01) for considering residual imbalance. The treatment effect was estimated using logistic regression that contained only those covariates considered to be unbalanced by these thresholds. We showed that regression adjustment could dramatically remove residual confounding bias when it included all of the covariates with a standardized difference greater than 0.10. The additional benefit was negligible when we also adjusted for covariates with less imbalance. We found that the mean squared error of the estimates was minimized under the same conditions. If covariate balance is not achieved, we recommend reiterating PS modeling until standardized differences below 0.10 are achieved on most covariates. In case of remaining imbalance, a double adjustment might be worth considering.

Incorporation of habitat information in the development of indices of larval bluefin tuna (Thunnus thynnus) in the Western Mediterranean Sea (2001-2005 and 2012-2013)

NASA Astrophysics Data System (ADS)

Ingram, G. Walter; Alvarez-Berastegui, Diego; Reglero, Patricia; Balbín, Rosa; García, Alberto; Alemany, Francisco

2017-06-01

Fishery independent indices of bluefin tuna larvae in the Western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 and 2012 through 2013. Indices were developed using larval catch rates collected using two different types of bongo sampling, by first standardizing catch rates by gear/fishing-style and then employing a delta-lognormal modeling approach. The delta-lognormal models were developed three ways: 1) a basic larval index including the following covariates: time of day, a systematic geographic area variable, month and year; 2) a standard environmental larval index including the following covariates: mean water temperature over the mixed layer depth, mean salinity over the mixed layer depth, geostrophic velocity, time of day, a systematic geographic area variable, month and year; and 3) a habitat-adjusted larval index including the following covariates: a potential habitat variable, time of day, a systematic geographic area variable, month and year. Results indicated that all three model-types had similar precision in index values. However, the habitat-adjusted larval index demonstrated a high correlation with estimates of spawning stock biomass from the previous stock assessment model, and, therefore, is recommended as a tuning index in future stock assessment models.

Approximation of properties of hyperelastic materials with use of energy-based models and biaxial tension data

NASA Astrophysics Data System (ADS)

Jamróz, Weronika

2016-06-01

The paper shows the way enrgy-based models aproximate mechanical properties of hiperelastic materials. Main goal of research was to create a method of finding a set of material constants that are included in a strain energy function that constitutes a heart of an energy-based model. The most optimal set of material constants determines the best adjustment of a theoretical stress-strain relation to the experimental one. This kind of adjustment enables better prediction of behaviour of a chosen material. In order to obtain more precised solution the approximation was made with use of data obtained in a modern experiment widely describen in [1]. To save computation time main algorithm is based on genetic algorithms.

Sexual orientation and self-rated health: the role of social capital, offence, threat of violence, and violence.

PubMed

Axelsson, Jakob; Modén, Birgit; Rosvall, Maria; Lindström, Martin

2013-07-01

To study the association between sexual orientation and self-rated health, including trust, offence, threat of violence, and violence. DESIGN/SETTING/PARTICIPANTS/MEASUREMENT: The 2008 Public Health Survey in Skåne is a cross-sectional postal questionnaire study. A total of 28,198 persons aged 18-80 years responded (55%). Logistic regressions analysed the association between sexual orientation and self-rated health. 27.4% of all men and 30.0% of all women rated their health as poor. Poor self-rated health was significantly more prevalent in higher age, among immigrants, people with lower education, low social support, low trust, experience of being offended, experience of threat of violence and violence, and bisexual and other orientation. Homosexual and bisexual men and women had higher age-adjusted odds ratios of having felt offended compared to heterosexual respondents. The odds ratios of low trust, threat of violence (men), and experience of violence (women) were significant for respondents with bisexual orientation but not for respondents with homosexual orientation. In the age-adjusted model, no significant association was observed between homosexual orientation and poor self-rated health among women. All other associations between sexual orientation and health were significant in the age-adjusted model but non-significant in the multiple models. Associations between sexual orientation and health disappear after multiple adjustments including trust and experience of offence, threat of violence, and violence. The study suggests that the group with bisexual orientation seems to be more exposed to low social capital (trust), threat of violence, and violence than the group with homosexual orientation.

77 FR 17219 - Patient Protection and Affordable Care Act; Standards Related to Reinsurance, Risk Corridors and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-23

... parts of the risk adjustment process--the risk adjustment model, the calculation of plan average... risk adjustment process. The risk adjustment model calculates individual risk scores. The calculation...'' to mean all data that are used in a risk adjustment model, the calculation of plan average actuarial...

Early parental adjustment and bereavement after childhood cancer death.

PubMed

Barrera, Maru; O'Connor, Kathleen; D'Agostino, Norma Mammone; Spencer, Lynlee; Nicholas, David; Jovcevska, Vesna; Tallet, Susan; Schneiderman, Gerald

2009-07-01

This study comprehensively explored parental bereavement and adjustment at 6 months post-loss due to childhood cancer. Interviews were conducted with 18 mothers and 13 fathers. Interviews were transcribed verbatim and analyzed based on qualitative methodology. A model describing early parental bereavement and adaptation emerged with 3 domains: (1) Perception of the Child, describing bereavement and adjustment prior to and after the loss; (2) Perception of Others, including relationships with partners, surviving children, and their social network; and (3) Perception of the World, exploring parents' perceived meanings of the experience in the context of their worldview. Domains are illustrated by quotes. Profiles of parental bereavement emerged.

Just another club? The distinctiveness of the relation between religious service attendance and adolescent psychosocial adjustment.

PubMed

Good, Marie; Willoughby, Teena; Fritjers, Jan

2009-10-01

This study used hierarchical linear modeling to compare longitudinal patterns of adolescent religious service attendance and club attendance, and to contrast the longitudinal relations between adolescent adjustment and religious service versus club attendance. Participants included 1050 students (47% girls) encompassing a school district in Canada, who completed the survey first in grade nine and again in grades 11 and 12. Results demonstrated that patterns of religious service attendance over time were quite different from other clubs. Religious attendance was uniquely associated with several indicators of positive as well as negative adjustment. Club involvement, conversely, was only associated with positive adjustment--particularly for individuals who reported sustained involvement over time. Findings suggest that religious services may provide some unique experiences--both positive and negative--over and above what may be provided in other clubs, and that sustained, rather than sporadic participation in clubs, may be especially important for adolescent adjustment.

Adaptation of SUBSTOR for controlled-environment potato production with elevated carbon dioxide

NASA Technical Reports Server (NTRS)

Fleisher, D. H.; Cavazzoni, J.; Giacomelli, G. A.; Ting, K. C.; Janes, H. W. (Principal Investigator)

2003-01-01

The SUBSTOR crop growth model was adapted for controlled-environment hydroponic production of potato (Solanum tuberosum L. cv. Norland) under elevated atmospheric carbon dioxide concentration. Adaptations included adjustment of input files to account for cultural differences between the field and controlled environments, calibration of genetic coefficients, and adjustment of crop parameters including radiation use efficiency. Source code modifications were also performed to account for the absorption of light reflected from the surface below the crop canopy, an increased leaf senescence rate, a carbon (mass) balance to the model, and to modify the response of crop growth rate to elevated atmospheric carbon dioxide concentration. Adaptations were primarily based on growth and phenological data obtained from growth chamber experiments at Rutgers University (New Brunswick, N.J.) and from the modeling literature. Modified-SUBSTOR predictions were compared with data from Kennedy Space Center's Biomass Production Chamber for verification. Results show that, with further development, modified-SUBSTOR will be a useful tool for analysis and optimization of potato growth in controlled environments.

Correction of Single Frequency Altimeter Measurements for Ionosphere Delay

NASA Technical Reports Server (NTRS)

Schreiner, William S.; Markin, Robert E.; Born, George H.

1997-01-01

This study is a preliminary analysis of the accuracy of various ionosphere models to correct single frequency altimeter height measurements for Ionospheric path delay. In particular, research focused on adjusting empirical and parameterized ionosphere models in the parameterized real-time ionospheric specification model (PRISM) 1.2 using total electron content (TEC) data from the global positioning system (GPS). The types of GPS data used to adjust PRISM included GPS line-of-sight (LOS) TEC data mapped to the vertical, and a grid of GPS derived TEC data in a sun-fixed longitude frame. The adjusted PRISM TEC values, as well as predictions by IRI-90, a climatotogical model, were compared to TOPEX/Poseidon (T/P) TEC measurements from the dual-frequency altimeter for a number of T/P tracks. When adjusted with GPS LOS data, the PRISM empirical model predicted TEC over 24 1 h data sets for a given local time to with in a global error of 8.60 TECU rms during a midnight centered ionosphere and 9.74 TECU rms during a noon centered ionosphere. Using GPS derived sun-fixed TEC data, the PRISM parameterized model predicted TEC within an error of 8.47 TECU rms centered at midnight and 12.83 TECU rms centered at noon. From these best results, it is clear that the proposed requirement of 3-4 TECU global rms for TOPEX/Poseidon Follow-On will be very difficult to meet, even with a substantial increase in the number of GPS ground stations, with any realizable combination of the aforementioned models or data assimilation schemes.

Meta-regression analysis to evaluate relationships between maternal blood levels of placentation biomarkers and low delivery weight.

PubMed

Goto, Eita

2018-05-03

Caution is required for women at increased risk of low neonatal delivery weight. To evaluate relationships between maternal placentation biomarkers and the odds of low delivery weight. Databases including PubMed/MEDLINE were searched up to May 2017 using keywords involving biomarker names and "low birthweight." English language studies providing true- and false-positive, and true- and false-negative results of low delivery weight classified by maternal blood levels of placentation biomarkers (in units of multiple of the mean [MoM]) were included. Coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood placentation biomarkers, and those adjusted for race, sampling period, and/or study quality were calculated. Adjusted coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood levels of α-fetoprotein (AFP) and β-human chorionic gonadotropin (β-hCG) were significantly greater than 0 (both P<0.001), whereas that for pregnancy-associated plasma protein A (PAPP-A) was significantly less than 0 (P=0.028). Adjusted models explained the higher proportion of between-study variance better than non-adjusted models. Elevated AFP and β-hCG, and reduced PAPP-A in maternal blood were positively associated with odds of low delivery weight. © 2018 International Federation of Gynecology and Obstetrics.

Effective System for Automatic Bundle Block Adjustment and Ortho Image Generation from Multi Sensor Satellite Imagery

NASA Astrophysics Data System (ADS)

Akilan, A.; Nagasubramanian, V.; Chaudhry, A.; Reddy, D. Rajesh; Sudheer Reddy, D.; Usha Devi, R.; Tirupati, T.; Radhadevi, P. V.; Varadan, G.

2014-11-01

Block Adjustment is a technique for large area mapping for images obtained from different remote sensingsatellites.The challenge in this process is to handle huge number of satellite imageries from different sources with different resolution and accuracies at the system level. This paper explains a system with various tools and techniques to effectively handle the end-to-end chain in large area mapping and production with good level of automation and the provisions for intuitive analysis of final results in 3D and 2D environment. In addition, the interface for using open source ortho and DEM references viz., ETM, SRTM etc. and displaying ESRI shapes for the image foot-prints are explained. Rigorous theory, mathematical modelling, workflow automation and sophisticated software engineering tools are included to ensure high photogrammetric accuracy and productivity. Major building blocks like Georeferencing, Geo-capturing and Geo-Modelling tools included in the block adjustment solution are explained in this paper. To provide optimal bundle block adjustment solution with high precision results, the system has been optimized in many stages to exploit the full utilization of hardware resources. The robustness of the system is ensured by handling failure in automatic procedure and saving the process state in every stage for subsequent restoration from the point of interruption. The results obtained from various stages of the system are presented in the paper.

Emergency Department Care in the Postpartum Period: California Births, 2009-2011.

PubMed

Batra, Priya; Fridman, Moshe; Leng, Mei; Gregory, Kimberly D

2017-11-01

To use population data to identify patient characteristics associated with a postpartum maternal emergency department visit within 90 days of discharge after birth. This retrospective cross-sectional study analyzed linked maternal discharge and emergency department data for all live California births from 2009 to 2011. The primary outcome was at least one emergency department visit within 90 days of hospital discharge after birth. Secondary outcomes included three or more visits within 90 days ("high utilization") and inpatient readmission. Independent variables included demographics (age, race or ethnicity, payer, income) and clinical characteristics (length of stay, antepartum complications, mode of delivery, and severe maternal morbidity at delivery). Multilevel logistic regression identified variables associated study outcomes; we validated the predictive model with a split-sample approach and receiver operating characteristic curve analysis. Of 1,071,232 deliveries included, 88,674 women (8.3%) visited the emergency department at least once in the 90 days after delivery discharge. Emergency department use was significantly associated with Medicaid insurance (adjusted odds ratio [OR] 2.15, 95% CI 2.08-2.21), age younger than 20 years (adjusted OR 2.08, 95% CI 1.98-2.19), severe maternal morbidity at delivery (adjusted OR 1.58, 95% CI 1.49-1.71), antepartum complications (adjusted OR 1.46, 95% CI 1.42-1.50), and cesarean delivery (adjusted OR 1.40, 95% CI 1.37-1.44). Approximately one fifth of visits occurred within 4 days of discharge, and more than half were within 3 weeks. High utilizers comprised 0.5% of the entire sample (5,171 women) and only 1.2% of women presenting for emergency department care were readmitted. Receiver operating curve model analysis using the validation sample supported predictive accuracy for postpartum emergency department use (area under the curve=0.95). One in 12 California women visited the emergency department in the first 90 days after postpartum discharge. Women at increased risk for postpartum emergency department use per our validated model (eg, low income, birth complications) may benefit from earlier scheduled postpartum visits.

Cognitive ability and risk of post-traumatic stress disorder after military deployment: an observational cohort study

PubMed Central

Karstoft, Karen-Inge; Vedtofte, Mia S.; Nielsen, Anni B.S.; Osler, Merete; Mortensen, Erik L.; Christensen, Gunhild T.; Andersen, Søren B.

2017-01-01

Background Studies of the association between pre-deployment cognitive ability and post-deployment post-traumatic stress disorder (PTSD) have shown mixed results. Aims To study the influence of pre-deployment cognitive ability on PTSD symptoms 6–8 months post-deployment in a large population while controlling for pre-deployment education and deployment-related variables. Method Study linking prospective pre-deployment conscription board data with post-deployment self-reported data in 9695 Danish Army personnel deployed to different war zones in 1997–2013. The association between pre-deployment cognitive ability and post-deployment PTSD was investigated using repeated-measure logistic regression models. Two models with cognitive ability score as the main exposure variable were created (model 1 and model 2). Model 1 was only adjusted for pre-deployment variables, while model 2 was adjusted for both pre-deployment and deployment-related variables. Results When including only variables recorded pre-deployment (cognitive ability score and educational level) and gender (model 1), all variables predicted post-deployment PTSD. When deployment-related variables were added (model 2), this was no longer the case for cognitive ability score. However, when educational level was removed from the model adjusted for deployment-related variables, the association between cognitive ability and post-deployment PTSD became significant. Conclusions Pre-deployment lower cognitive ability did not predict post-deployment PTSD independently of educational level after adjustment for deployment-related variables. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:29163983

Modular Bundle Adjustment for Photogrammetric Computations

NASA Astrophysics Data System (ADS)

Börlin, N.; Murtiyoso, A.; Grussenmeyer, P.; Menna, F.; Nocerino, E.

2018-05-01

In this paper we investigate how the residuals in bundle adjustment can be split into a composition of simple functions. According to the chain rule, the Jacobian (linearisation) of the residual can be formed as a product of the Jacobians of the individual steps. When implemented, this enables a modularisation of the computation of the bundle adjustment residuals and Jacobians where each component has limited responsibility. This enables simple replacement of components to e.g. implement different projection or rotation models by exchanging a module. The technique has previously been used to implement bundle adjustment in the open-source package DBAT (Börlin and Grussenmeyer, 2013) based on the Photogrammetric and Computer Vision interpretations of Brown (1971) lens distortion model. In this paper, we applied the technique to investigate how affine distortions can be used to model the projection of a tilt-shift lens. Two extended distortion models were implemented to test the hypothesis that the ordering of the affine and lens distortion steps can be changed to reduce the size of the residuals of a tilt-shift lens calibration. Results on synthetic data confirm that the ordering of the affine and lens distortion steps matter and is detectable by DBAT. However, when applied to a real camera calibration data set of a tilt-shift lens, no difference between the extended models was seen. This suggests that the tested hypothesis is false and that other effects need to be modelled to better explain the projection. The relatively low implementation effort that was needed to generate the models suggest that the technique can be used to investigate other novel projection models in photogrammetry, including modelling changes in the 3D geometry to better understand the tilt-shift lens.

Comparative study of the Aristotle Comprehensive Complexity and the Risk Adjustment in Congenital Heart Surgery scores.

PubMed

Bojan, Mirela; Gerelli, Sébastien; Gioanni, Simone; Pouard, Philippe; Vouhé, Pascal

2011-09-01

The Aristotle Comprehensive Complexity (ACC) and the Risk Adjustment in Congenital Heart Surgery (RACHS-1) scores have been proposed for complexity adjustment in the analysis of outcome after congenital heart surgery. Previous studies found RACHS-1 to be a better predictor of outcome than the Aristotle Basic Complexity score. We compared the ability to predict operative mortality and morbidity between ACC, the latest update of the Aristotle method and RACHS-1. Morbidity was assessed by length of intensive care unit stay. We retrospectively enrolled patients undergoing congenital heart surgery. We modeled each score as a continuous variable, mortality as a binary variable, and length of stay as a censored variable. We compared performance between mortality and morbidity models using likelihood ratio tests for nested models and paired concordance statistics. Among all 1,384 patients enrolled, 30-day mortality rate was 3.5% and median length of intensive care unit stay was 3 days. Both scores strongly related to mortality, but ACC made better prediction than RACHS-1; c-indexes 0.87 (0.84, 0.91) vs 0.75 (0.65, 0.82). Both scores related to overall length of stay only during the first postoperative week, but ACC made better predictions than RACHS-1; U statistic=0.22, p<0.001. No significant difference was noted after adjusting RACHS-1 models on age, prematurity, and major extracardiac abnormalities. The ACC was a better predictor of operative mortality and length of intensive care unit stay than RACHS-1. In order to achieve similar performance, regression models including RACHS-1 need to be further adjusted on age, prematurity, and major extracardiac abnormalities. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Narrow gap laser welding

DOEpatents

Milewski, John O.; Sklar, Edward

1998-01-01

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables.

Narrow gap laser welding

DOEpatents

Milewski, J.O.; Sklar, E.

1998-06-02

A laser welding process including: (a) using optical ray tracing to make a model of a laser beam and the geometry of a joint to be welded; (b) adjusting variables in the model to choose variables for use in making a laser weld; and (c) laser welding the joint to be welded using the chosen variables. 34 figs.

Mexican-Origin Youth's Cultural Orientations and Adjustment: Changes from Early to Late Adolescence

PubMed Central

Updegraff, Kimberly A.; Umaña-Taylor, Adriana J.; McHale, Susan M.; Wheeler, Lorey A.; Perez-Brena, Norma

2013-01-01

Drawing from developmental and cultural adaptation perspectives and using a longitudinal design, this study examined: (a) mean-level changes in Mexican-origin adolescents’ cultural orientations and adjustment from early to late adolescence; and (b) bidirectional associations between cultural orientations and adjustment using a cross-lag panel model. Participants included 246 Mexican-origin, predominantly immigrant families that participated in home interviews and a series of nightly phone calls when target adolescents were 12 years and 18 years of age. Girls exhibited more pronounced declines in traditional gender role attitudes than did boys, and all youth declined in familism values, time spent with family, and involvement in Mexican culture. Bidirectional relations between cultural orientations and adjustment emerged, and some associations were moderated by adolescent nativity and gender. PMID:22966929

Parenting and Adolescent Self-Regulation Mediate between Family Socioeconomic Status and Adolescent Adjustment

PubMed Central

Farley, Julee P.; Kim-Spoon, Jungmeen

2016-01-01

Using two waves of longitudinal data, we utilized the family stress model of economic hardship (Conger & Conger, 2002) to test whether family socioeconomic status is related to adolescent adjustment (substance use and academic achievement) through parental knowledge and adolescent self-regulation (behavioral self-control and delay discounting). Participants included 220 adolescent (55% male, mean age = 13 years at Wave 1, mean age = 15 years at Wave 2) and primary caregiver dyads. Results of Structural Equation Modeling revealed significant three-path mediation effects such that low family socioeconomic status at Wave 1 is associated with low parental knowledge at Wave 1, which in turn was related to low academic performance and high substance use at Wave 2 mediated through low adolescent behavioral self-control at Wave 2. The results illustrate how parental knowledge, influenced by family economic status, may play an important role in the development of adolescent behavioral self-control and adjustment. PMID:28348448

Controlled cooling of an electronic system based on projected conditions

DOEpatents

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

2016-05-17

Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

Controlled cooling of an electronic system based on projected conditions

DOEpatents

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

2015-08-18

Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

Benchmarking antibiotic use in Finnish acute care hospitals using patient case-mix adjustment.

PubMed

Kanerva, Mari; Ollgren, Jukka; Lyytikäinen, Outi

2011-11-01

It is difficult to draw conclusions about the prudence of antibiotic use in different hospitals by directly comparing usage figures. We present a patient case-mix adjustment model of antibiotic use to rank hospitals while taking patient characteristics into account. Data on antibiotic use were collected during the national healthcare-associated infection (HAI) prevalence survey in 2005 in Finland in all 5 tertiary care, all 15 secondary care and 10 (25% of 40) other acute care hospitals. The use of antibiotics was measured using use-days/100 patient-days during a 7day period and the prevalence of patients receiving at least two antimicrobials during the study day. Case-mix-adjusted antibiotic use was calculated by using multivariate models and an indirect standardization method. Parameters in the model included age, sex, severity of underlying diseases, intensive care, haematology, preceding surgery, respirator, central venous and urinary catheters, community-associated infection, HAI and contact isolation due to methicillin-resistant Staphylococcus aureus. The ranking order changed one position in 12 (40%) hospitals and more than two positions in 13 (43%) hospitals when the case-mix-adjusted figures were compared with those observed. In 24 hospitals (80%), the antibiotic use density observed was lower than expected by the case-mix-adjusted use density. The patient case-mix adjustment of antibiotic use ranked the hospitals differently from the ranking according to observed use, and may be a useful tool for benchmarking hospital antibiotic use. However, the best set of easily and widely available parameters that would describe both patient material and hospital activities remains to be determined.

Secular trends and climate drift in coupled ocean-atmosphere general circulation models

NASA Astrophysics Data System (ADS)

Covey, Curt; Gleckler, Peter J.; Phillips, Thomas J.; Bader, David C.

2006-02-01

Coupled ocean-atmosphere general circulation models (coupled GCMs) with interactive sea ice are the primary tool for investigating possible future global warming and numerous other issues in climate science. A long-standing problem with such models is that when different components of the physical climate system are linked together, the simulated climate can drift away from observation unless constrained by ad hoc adjustments to interface fluxes. However, 11 modern coupled GCMs, including three that do not employ flux adjustments, behave much better in this respect than the older generation of models. Surface temperature trends in control run simulations (with external climate forcing such as solar brightness and atmospheric carbon dioxide held constant) are small compared with observed trends, which include 20th century climate change due to both anthropogenic and natural factors. Sea ice changes in the models are dominated by interannual variations. Deep ocean temperature and salinity trends are small enough for model control runs to extend over 1000 simulated years or more, but trends in some regions, most notably the Arctic, differ substantially among the models and may be problematic. Methods used to initialize coupled GCMs can mitigate climate drift but cannot eliminate it. Lengthy "spin-ups" of models, made possible by increasing computer power, are one reason for the improvements this paper documents.

Differences in sensitivity to parenting depending on child temperament: A meta-analysis.

PubMed

Slagt, Meike; Dubas, Judith Semon; Deković, Maja; van Aken, Marcel A G

2016-10-01

Several models of individual differences in environmental sensitivity postulate increased sensitivity of some individuals to either stressful (diathesis-stress), supportive (vantage sensitivity), or both environments (differential susceptibility). In this meta-analysis we examine whether children vary in sensitivity to parenting depending on their temperament, and if so, which model can best be used to describe this sensitivity pattern. We tested whether associations between negative parenting and negative or positive child adjustment as well as between positive parenting and positive or negative child adjustment would be stronger among children higher on putative sensitivity markers (difficult temperament, negative emotionality, surgency, and effortful control). Longitudinal studies with children up to 18 years (k = 105 samples from 84 studies, Nmean = 6,153) that reported on a parenting-by-temperament interaction predicting child adjustment were included. We found 235 independent effect sizes for associations between parenting and child adjustment. Results showed that children with a more difficult temperament (compared with those with a more easy temperament) were more vulnerable to negative parenting, but also profited more from positive parenting, supporting the differential susceptibility model. Differences in susceptibility were expressed in externalizing and internalizing problems and in social and cognitive competence. Support for differential susceptibility for negative emotionality was, however, only present when this trait was assessed during infancy. Surgency and effortful control did not consistently moderate associations between parenting and child adjustment, providing little support for differential susceptibility, diathesis-stress, or vantage sensitivity models. Finally, parenting-by-temperament interactions were more pronounced when parenting was assessed using observations compared to questionnaires. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Affordable Care Act risk adjustment: overview, context, and challenges.

PubMed

Kautter, John; Pope, Gregory C; Keenan, Patricia

2014-01-01

Beginning in 2014, individuals and small businesses will be able to purchase private health insurance through competitive marketplaces. The Affordable Care Act (ACA) provides for a program of risk adjustment in the individual and small group markets in 2014 as Marketplaces are implemented and new market reforms take effect. The purpose of risk adjustment is to lessen or eliminate the influence of risk selection on the premiums that plans charge and the incentive for plans to avoid sicker enrollees. This article--the first of three in the Medicare & Medicaid Research Review--describes the key program goal and issues in the Department of Health and Human Services (HHS) developed risk adjustment methodology, and identifies key choices in how the methodology responds to these issues. The goal of the HHS risk adjustment methodology is to compensate health insurance plans for differences in enrollee health mix so that plan premiums reflect differences in scope of coverage and other plan factors, but not differences in health status. The methodology includes a risk adjustment model and a risk transfer formula that together address this program goal as well as three issues specific to ACA risk adjustment: 1) new population; 2) cost and rating factors; and 3) balanced transfers within state/market. The risk adjustment model, described in the second article, estimates differences in health risks taking into account the new population and scope of coverage (actuarial value level). The transfer formula, described in the third article, calculates balanced transfers that are intended to account for health risk differences while preserving permissible premium differences.

A Review of Sex Differences in Peer Relationship Processes: Potential Trade-offs for the Emotional and Behavioral Development of Girls and Boys

PubMed Central

Rose, Amanda J.; Rudolph, Karen D.

2011-01-01

Theory and research on sex differences in adjustment focus largely on parental, societal, and biological influences. However, it also is important to consider how peers contribute to girls’ and boys’ development. This paper provides a critical review of sex differences in: several peer-relationship processes, including behavioral and social-cognitive styles, stress and coping, and relationship provisions. Based on this review, a speculative peer-socialization model is presented that considers the implications of these sex differences for girls’ and boys’ emotional and behavioral development. Central to this model is the idea that sex-linked relationship processes have costs and benefits for girls’ and boys’ adjustment. Finally, we present recent research testing certain model components and propose approaches for testing understudied aspects of the model. PMID:16435959

Estimating the "impact" of out-of-home placement on child well-being: approaching the problem of selection bias.

PubMed

Berger, Lawrence M; Bruch, Sarah K; Johnson, Elizabeth I; James, Sigrid; Rubin, David

2009-01-01

This study used data on 2,453 children aged 4-17 from the National Survey of Child and Adolescent Well-Being and 5 analytic methods that adjust for selection factors to estimate the impact of out-of-home placement on children's cognitive skills and behavior problems. Methods included ordinary least squares (OLS) regressions and residualized change, simple change, difference-in-difference, and fixed effects models. Models were estimated using the full sample and a matched sample generated by propensity scoring. Although results from the unmatched OLS and residualized change models suggested that out-of-home placement is associated with increased child behavior problems, estimates from models that more rigorously adjust for selection bias indicated that placement has little effect on children's cognitive skills or behavior problems.

Influence of adult attachment insecurities on parenting self-esteem: the mediating role of dyadic adjustment

PubMed Central

Calvo, Vincenzo; Bianco, Francesca

2015-01-01

Background: Parenting self-esteem includes two global components, parents’ self-efficacy and satisfaction with their parental role, and has a crucial role in parent–child interactions. The purpose of this study was to develop an integrative model linking adult attachment insecurities, dyadic adjustment, and parenting self-esteem. Methods: The study involved 118 pairs (236 subjects) of heterosexual parents of a firstborn child aged 0–6 years. They were administered the Experiences in Close Relationships-Revised (ECR-R) questionnaire, the Dyadic Adjustment Scale, and the Parenting Sense of Competence Scale. Results: Path analysis was used to design and test a theoretical integrative model, achieving a good fit with the data. Findings showed that dyadic adjustment mediates the negative influence on parenting self-efficacy of both attachment anxiety and attachment avoidance. Parenting satisfaction is positively influenced by parenting self-efficacy and negatively affected by child’s age. Attachment anxiety negatively influences parenting satisfaction. Conclusion: Our findings are in line with the theoretical expectations and have promising implications for future research and intervention programs designed to improve parenting self-esteem. PMID:26441811

Influence of adult attachment insecurities on parenting self-esteem: the mediating role of dyadic adjustment.

PubMed

Calvo, Vincenzo; Bianco, Francesca

2015-01-01

Parenting self-esteem includes two global components, parents' self-efficacy and satisfaction with their parental role, and has a crucial role in parent-child interactions. The purpose of this study was to develop an integrative model linking adult attachment insecurities, dyadic adjustment, and parenting self-esteem. The study involved 118 pairs (236 subjects) of heterosexual parents of a firstborn child aged 0-6 years. They were administered the Experiences in Close Relationships-Revised (ECR-R) questionnaire, the Dyadic Adjustment Scale, and the Parenting Sense of Competence Scale. Path analysis was used to design and test a theoretical integrative model, achieving a good fit with the data. Findings showed that dyadic adjustment mediates the negative influence on parenting self-efficacy of both attachment anxiety and attachment avoidance. Parenting satisfaction is positively influenced by parenting self-efficacy and negatively affected by child's age. Attachment anxiety negatively influences parenting satisfaction. Our findings are in line with the theoretical expectations and have promising implications for future research and intervention programs designed to improve parenting self-esteem.

Improved Horvitz-Thompson Estimation of Model Parameters from Two-phase Stratified Samples: Applications in Epidemiology

PubMed Central

Breslow, Norman E.; Lumley, Thomas; Ballantyne, Christie M; Chambless, Lloyd E.; Kulich, Michal

2009-01-01

The case-cohort study involves two-phase sampling: simple random sampling from an infinite super-population at phase one and stratified random sampling from a finite cohort at phase two. Standard analyses of case-cohort data involve solution of inverse probability weighted (IPW) estimating equations, with weights determined by the known phase two sampling fractions. The variance of parameter estimates in (semi)parametric models, including the Cox model, is the sum of two terms: (i) the model based variance of the usual estimates that would be calculated if full data were available for the entire cohort; and (ii) the design based variance from IPW estimation of the unknown cohort total of the efficient influence function (IF) contributions. This second variance component may be reduced by adjusting the sampling weights, either by calibration to known cohort totals of auxiliary variables correlated with the IF contributions or by their estimation using these same auxiliary variables. Both adjustment methods are implemented in the R survey package. We derive the limit laws of coefficients estimated using adjusted weights. The asymptotic results suggest practical methods for construction of auxiliary variables that are evaluated by simulation of case-cohort samples from the National Wilms Tumor Study and by log-linear modeling of case-cohort data from the Atherosclerosis Risk in Communities Study. Although not semiparametric efficient, estimators based on adjusted weights may come close to achieving full efficiency within the class of augmented IPW estimators. PMID:20174455

An analysis of security price risk and return among publicly traded pharmacy corporations.

PubMed

Gilligan, Adrienne M; Skrepnek, Grant H

2013-01-01

Community pharmacies have been subject to intense and increasing competition in the past several decades. To determine the security price risk and rate of return of publicly traded pharmacy corporations present on the major U.S. stock exchanges from 1930 to 2009. The Center of Research in Security Prices (CRSP) database was used to examine monthly security-level stock market prices in this observational retrospective study. The primary outcome of interest was the equity risk premium, with analyses focusing upon financial metrics associated with risk and return based upon modern portfolio theory (MPT) including: abnormal returns (i.e., alpha), volatility (i.e., beta), and percentage of returns explained (i.e., adjusted R(2)). Three equilibrium models were estimated using random-effects generalized least squares (GLS): 1) the Capital Asset Pricing Model (CAPM); 2) Fama-French Three-Factor Model; and 3) Carhart Four-Factor Model. Seventy-five companies were examined from 1930 to 2009, with overall adjusted R(2) values ranging from 0.13 with the CAPM to 0.16 with the Four-Factor model. Alpha was not significant within any of the equilibrium models across the entire 80-year time period, though was found from 1999 to 2009 in the Three- and Four-Factor models to be associated with a large, significant, and negative risk-adjusted abnormal returns of -33.84%. Volatility varied across specific time periods based upon the financial model employed. This investigation of risk and return within publicly listed pharmacy corporations from 1930 to 2009 found that substantial losses were incurred particularly from 1999 to 2009, with risk-adjusted security valuations decreasing by one-third. Copyright © 2013 Elsevier Inc. All rights reserved.

The cataract national data set electronic multi-centre audit of 55,567 operations: case-mix adjusted surgeon's outcomes for posterior capsule rupture.

PubMed

Sparrow, J M; Taylor, H; Qureshi, K; Smith, R; Johnston, R L

2011-08-01

To develop a methodology for case-mix adjustment of surgical outcomes for individual cataract surgeons using electronically collected multi-centre data conforming to the cataract national data set (CND). Routinely collected anonymised data were remotely extracted from electronic patient record (EPR) systems in 12 participating NHS Trusts undertaking cataract surgery. Following data checks and cleaning, analyses were carried out to risk adjust outcomes for posterior capsule rupture rates for individual surgeons, with stratification by surgical grade. A total of 406 surgeons from 12 NHS Trusts submitted data on 55,567 cataract operations between November 2001 and July 2006 (86% from January 2004). In all, 283 surgeons contributed data on >25 cases, providing 54,319 operations suitable for detailed analysis. Case-mix adjusted results of individual surgeons are presented as funnel plots for all surgeons together, and separately for three different grades of surgeon. Plots include 95 and 99.8% confidence limits around the case-mix adjusted outcomes for detection of surgical outliers. Routinely collected electronic data conforming to the CND provides sufficient detail for case-mix adjustment of cataract surgical outcomes. The validation of these risk indicators should be carried out using fresh data to confirm the validity of the risk model. Once validated this model should provide an equitable approach for peer-to-peer comparisons in the context of revalidation.

When does female multiple mating evolve to adjust inbreeding? Effects of inbreeding depression, direct costs, mating constraints, and polyandry as a threshold trait.

PubMed

Duthie, A Bradley; Bocedi, Greta; Reid, Jane M

2016-09-01

Polyandry is often hypothesized to evolve to allow females to adjust the degree to which they inbreed. Multiple factors might affect such evolution, including inbreeding depression, direct costs, constraints on male availability, and the nature of polyandry as a threshold trait. Complex models are required to evaluate when evolution of polyandry to adjust inbreeding is predicted to arise. We used a genetically explicit individual-based model to track the joint evolution of inbreeding strategy and polyandry defined as a polygenic threshold trait. Evolution of polyandry to avoid inbreeding only occurred given strong inbreeding depression, low direct costs, and severe restrictions on initial versus additional male availability. Evolution of polyandry to prefer inbreeding only occurred given zero inbreeding depression and direct costs, and given similarly severe restrictions on male availability. However, due to its threshold nature, phenotypic polyandry was frequently expressed even when strongly selected against and hence maladaptive. Further, the degree to which females adjusted inbreeding through polyandry was typically very small, and often reflected constraints on male availability rather than adaptive reproductive strategy. Evolution of polyandry solely to adjust inbreeding might consequently be highly restricted in nature, and such evolution cannot necessarily be directly inferred from observed magnitudes of inbreeding adjustment. © 2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Generation of Adaptive Gait Patterns for Quadruped Robot with CPG Network including Motor Dynamic Model

NASA Astrophysics Data System (ADS)

Son, Yurak; Kamano, Takuya; Yasuno, Takashi; Suzuki, Takayuki; Harada, Hironobu

This paper describes the generation of adaptive gait patterns using new Central Pattern Generators (CPGs) including motor dynamic models for a quadruped robot under various environment. The CPGs act as the flexible oscillators of the joints and make the desired angle of the joints. The CPGs are mutually connected each other, and the sets of their coupling parameters are adjusted by genetic algorithm so that the quadruped robot can realize the stable and adequate gait patterns. As a result of generation, the suitable CPG networks for not only a walking straight gait pattern but also rotation gait patterns are obtained. Experimental results demonstrate that the proposed CPG networks are effective to automatically adjust the adaptive gait patterns for the tested quadruped robot under various environment. Furthermore, the target tracking control based on image processing is achieved by combining the generated gait patterns.

Association between maternal health literacy and child vaccination in India: a cross-sectional study.

PubMed

Johri, Mira; Subramanian, S V; Sylvestre, Marie-Pierre; Dudeja, Sakshi; Chandra, Dinesh; Koné, Georges K; Sharma, Jitendar K; Pahwa, Smriti

2015-09-01

Education of mothers may improve child health. We investigated whether maternal health literacy, a rapidly modifiable factor related to mother's education, was associated with children's receipt of vaccines in two underserved Indian communities. Cross-sectional surveys in an urban and a rural site. We assessed health literacy using Indian child health promotion materials. The outcome was receipt of three doses of diphtheria-tetanus-pertussis (DTP3) vaccine. We used multivariate logistic regression to investigate the relationship between maternal health literacy and vaccination status independently in each site. For both sites, adjusted models considered maternal age, maternal and paternal education, child sex, birth order, household religion and wealth quintile. Rural analyses used multilevel models adjusted for service delivery characteristics. Urban analyses represented cluster characteristics through fixed effects. The rural analysis included 1170 women from 60 villages. The urban analysis included 670 women from nine slum clusters. In each site, crude and adjusted models revealed a positive association between maternal health literacy and DTP3. In the rural site, the adjusted OR was 1.57 (95% CI 1.11 to 2.21, p=0.010) for those with medium health literacy, and OR=1.30 (95% CI 0.89 to 1.91, p=0.172) for those with high health literacy. In the urban site, the adjusted OR was 1.10 (95% CI 0.65 to 1.88, p=0.705) for those with medium health literacy, and OR=2.06 (95% CI 1.06 to 3.99, p=0.032) for those with high health literacy. In these study settings, maternal health literacy is independently associated with child vaccination. Initiatives targeting health literacy could improve vaccination coverage. 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.

Exploring the Relationship Between Resilience and Ostomy Adjustment in Adults With a Permanent Ostomy.

PubMed

Scardillo, Jody; Dunn, Karen S; Piscotty, Ronald

2016-01-01

The aims of this study were to describe the relationship between resilience and ostomy adjustment in adults with permanent stomas and to determine if participants who report higher levels of resilience also report higher levels of adjustment to a permanent ostomy. Descriptive, correlational research design utilizing the Roy Adaptation Model as the theoretical framework was used. Persons with permanent stomas were recruited from ostomy support groups on the East Coast of the United States. The study sample included 48 respondents. Their mean age was 66 ± 12.7 years (mean ± SD); the majority (60.4%) were women, had an ileostomy (62.5%), and had a history of inflammatory bowel disease (62.5%). Respondents completed a questionnaire that queried demographic and pertinent clinical data, along with 2 previously validated instruments, the Resilience Scale and Ostomy Adjustment Inventory-23. The relationships between levels of resilience, levels of adjustment to an ostomy, and demographic characteristics were examined. Participants with higher levels of ostomy adjustment had higher levels of resilience than respondents who reported lower levels of ostomy adjustment (r = 0.65, P ≤ .01). Findings from this study suggest that higher levels of resilience facilitate adjustment to a permanent ostomy.

Differences in motor performance between children and adolescents in Mozambique and Portugal: impact of allometric scaling.

PubMed

Dos Santos, Fernanda Karina; Nevill, Allan; Gomes, Thayse Natacha Q F; Chaves, Raquel; Daca, Timóteo; Madeira, Aspacia; Katzmarzyk, Peter T; Prista, António; Maia, José A R

2016-05-01

Children from developed and developing countries have different anthropometric characteristics which may affect their motor performance (MP). To use the allometric approach to model the relationship between body size and MP in youth from two countries differing in socio-economic status-Portugal and Mozambique. A total of 2946 subjects, 1280 Mozambicans (688 girls) and 1666 Portuguese (826 girls), aged 10-15 years were sampled. Height and weight were measured and the reciprocal ponderal index (RPI) was computed. MP included handgrip strength, 1-mile run/walk, curl-ups and standing long jump tests. A multiplicative allometric model was adopted to adjust for body size differences across countries. Differences in MP between Mozambican and Portuguese children exist, invariably favouring the latter. The allometric models used to adjust MP for differences in body size identified the optimal body shape to be either the RPI or even more linear, i.e. approximately (height/mass(0.25)). Having adjusted the MP variables for differences in body size, the differences between Mozambican and Portuguese children were invariably reduced and, in the case of grip strength, reversed. These results reinforce the notion that significant differences exist in MP across countries, even after adjusting for differences in body size.

A concordance-based study to assess doctors’ and nurses’ mental models in Internal Medicine

PubMed Central

Chan, K. C. Gary; Muller-Juge, Virginie; Cullati, Stéphane; Hudelson, Patricia; Maître, Fabienne; Vu, Nu V.; Savoldelli, Georges L.; Nendaz, Mathieu R.

2017-01-01

Interprofessional collaboration between doctors and nurses is based on team mental models, in particular for each professional’s roles. Our objective was to identify factors influencing concordance on the expectations of doctors’ and nurses’ roles and responsibilities in an Internal Medicine ward. Using a dataset of 196 doctor-nurse pairs (14x14 = 196), we analyzed choices and prioritized management actions of 14 doctors and 14 nurses in six clinical nurse role scenarios, and in five doctor role scenarios (6 options per scenario). In logistic regression models with a non-nested correlation structure, we evaluated concordance among doctors and nurses, and adjusted for potential confounders (including prior experience in Internal Medicine, acuteness of case and gender). Concordance was associated with number of female professionals (adjusted OR 1.32, 95% CI 1.02 to 1.73), for acute situations (adjusted OR 2.02, 95% CI 1.13 to 3.62), and in doctor role scenarios (adjusted OR 2.19, 95% CI 1.32 to 3.65). Prior experience and country of training were not significant predictors of concordance. In conclusion, our concordance-based approach helped us identify areas of lower concordance in expected doctor-nurse roles and responsibilities, particularly in non-acute situations, which can be targeted by future interprofessional, educational interventions. PMID:28792524

Relationship between peer victimization and school adjustment in sixth-grade students: investigating mediation effects.

PubMed

Wei, Hsi-Sheng; Williams, James Herbert

2004-10-01

Peer victimization is a common occurrence in school settings. This study investigated the relationship between peer victimization and school adjustment in a sample of 1,022 sixth-grade students. Measures used in this study include peer victimization, perceived peer non-support, school attachment, inattention problems, and academic achievement. Multivariate path analyses were conducted to test direct and mediation effects in the over-all model and to explore gender differences. The results provided support for the hypothesized model indicating that the relationship between peer victimization and school attachment is mediated by perceived peer non-support, and that school attachment is related to inattentive school behaviors and poor academic achievement. Paths indicated invariance across models for gender. Prevention and intervention implications of these findings are discussed.

The Economic Impact of Blindness in Europe.

PubMed

Chakravarthy, Usha; Biundo, Eliana; Saka, Rasit Omer; Fasser, Christina; Bourne, Rupert; Little, Julie-Anne

2017-08-01

To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) in the population aged >50 years in the European Union (EU). We estimated the cost of lost productivity using three simple models reported in the literature based on (1) minimum wage (MW), (2) gross national income (GNI), and (3) purchasing power parity-adjusted gross domestic product (GDP-PPP) losses. In the first two models, assumptions included that all individuals worked until 65 years of age, and that half of all visual impairment cases in the >50-year age group would be in those aged between 50 and 65 years. Loss of productivity was estimated to be 100% for blind individuals and 30% for those with MSVI. None of these models included direct medical costs related to visual impairment. The estimated number of blind people in the EU population aged >50 years is ~1.28 million, with a further 9.99 million living with MSVI. Based on the three models, the estimated cost of blindness is €7.81 billion, €6.29 billion and €17.29 billion and that of MSVI €18.02 billion, €24.80 billion and €39.23 billion, with their combined costs €25.83 billion, €31.09 billion and €56.52 billion, respectively. The estimates from the MW and adjusted GDP-PPP models were generally comparable, whereas the GNI model estimates were higher, probably reflecting the lack of adjustment for unemployment. The cost of blindness and MSVI in the EU is substantial. Wider use of available cost-effective treatment and prevention strategies may reduce the burden significantly.

Physically Modeling Stream Channel Adjustment to Woody Riparian Vegetation

NASA Astrophysics Data System (ADS)

Bennett, S. J.; Alonso, C. V.

2003-12-01

Stream restoration designs often use vegetation to promote bank and channel stability, to facilitate point-bar development, and to encourage natural colonization of riparian species. Here we examine the adjustment of an alluvial channel to in-stream and riparian vegetation using a distorted Froude-scale flume model with a movable boundary. A decimeter-scale trapezoidal channel comprised of 0.8-mm diameter sand was systematically vegetated with emergent, rigid dowels (3-mm in diameter) in rectangular and hemispherical patterns with varying vegetation densities while conserving the shape of the zone and the geometry of the vegetal patterns. Alternate sides of the channel were vegetated at the prescribed spacing of equilibrium alternate bars, ca. 5 to 7 times the channel width. Using flow conditions just below the threshold of sediment motion, flow obstruction, deflection, and acceleration caused bed erosion, bank failure, and morphologic channel adjustments that were wholly attributable to the managed plantings. As vegetation density increased, the magnitude and rate of scaled channel adjustment increased, which included increased channel widths, bankline steepening and meandering, and thalweg meandering. As the modeled channel began to meander, the stream bed aggraded and flow depth decreased markedly, creating a continuously connected, inter-reach complex of mid-channel bars. This study demonstrates the utility of using managed vegetations in stream corridor design and meander development, and it provides the practitioner with guidance on the magnitude of channel adjustment as it relates to vegetation density, shape, and spacing.

Simultaneous Prediction of New Morbidity, Mortality, and Survival without New Morbidity from Pediatric Intensive Care: A New Paradigm for Outcomes Assessment

PubMed Central

Pollack, Murray M.; Holubkov, Richard; Funai, Tomohiko; Berger, John T.; Clark, Amy E.; Meert, Kathleen; Berg, Robert A.; Carcillo, Joseph; Wessel, David L.; Moler, Frank; Dalton, Heidi; Newth, Christopher J. L.; Shanley, Thomas; Harrison, Rick E.; Doctor, Allan; Jenkins, Tammara L.; Tamburro, Robert; Dean, J. Michael

2015-01-01

Objective Assessments of care including quality assessments adjusted for physiological status should include the development of new morbidities as well as mortalities. We hypothesized that morbidity, like mortality, is associated with physiological dysfunction and could be predicted simultaneously with mortality. Design Prospective cohort study from December 4, 2011 to April 7, 2013. Setting and Patients General and cardiac/cardiovascular pediatric intensive care units at 7 sites. Measurements and Main Results Among 10,078 admissions, the unadjusted morbidity rates (measured with the Functional Status Scale (FSS), and defined as an increase of ≥ 3 from pre-illness to hospital discharge) were 4.6% (site range 2.6% to 7.7%) and unadjusted mortality rates were 2.7% (site range 1.3% – 5.0%). Morbidity and mortality were significantly (p<0.001) associated with physiological instability (measured with the PRISM III score) in dichotomous (survival, death) and trichotomous (survival without new morbidity, survival with new morbidity, death) models without covariate adjustments. Morbidity risk increased with increasing PRISM III scores and then decreased at the highest PRISM III values as potential morbidities became mortalities. The trichotomous model with covariate adjustments included age, admission source, diagnostic factors, baseline FSS and the PRISM III score. The three-level goodness of fit test indicated satisfactory performance for the derivation and validation sets (p>0.20). Predictive ability assessed with the volume under the surface (VUS) was 0.50 ± 0.019 (derivation) and 0.50 ± 0.034 (validation) (versus chance performance = 0.17). Site-level standardized morbidity ratios were more variable than standardized mortality ratios. Conclusions New morbidities were associated with physiological status and can be modeled simultaneously with mortality. Trichotomous outcome models including both morbidity and mortality based on physiological status are suitable for research studies, and quality and other outcome assessments. This approach may be applicable to other assessments presently based only on mortality. PMID:25985385

Applications of General Systems Theory to the Development of an Adjustable Tutorial Software Machine.

ERIC Educational Resources Information Center

Vos, Hans J.

1994-01-01

Describes the construction of a model of computer-assisted instruction using a qualitative block diagram based on general systems theory (GST) as a framework. Subject matter representation is discussed, and appendices include system variables and system equations of the GST model, as well as an example of developing flexible courseware. (Contains…

A General Linear Model Approach to Adjusting the Cumulative GPA.

ERIC Educational Resources Information Center

Young, John W.

A general linear model (GLM), using least-squares techniques, was used to develop a criterion measure to replace freshman year grade point average (GPA) in college admission predictive validity studies. Problems with the use of GPA include those associated with the combination of grades from different courses and disciplines into a single measure,…

Parental and Peer Support as Predictors of Depression and Self-Esteem among College Students

ERIC Educational Resources Information Center

Li, Susan Tinsley; Albert, Arielle Berman; Dwelle, Deborah G.

2014-01-01

We investigated the relationship between parent support and peer support as predictors of depression and self-esteem in college students. Several competing models of parental and peer influence were compared including a mediational model in which peer support was hypothesized to mediate the effects of parental support on adjustment. The results…

Conceptual design and feasibility evaluation model of a 10 to the 8th power bit oligatomic mass memory. Volume 3: Operation manual

NASA Technical Reports Server (NTRS)

Horst, R. L.; Nordstrom, M. J.

1972-01-01

An operation manual is presented for the oligatomic mass memory feasibility model. It includes a brief description of the memory and exerciser units, a description of the controls and their functions, the operating procedures, the test points and adjustments, and the circuit diagram.

Parenting and family adjustment scales (PAFAS): validation of a brief parent-report measure for use with families who have a child with a developmental disability.

PubMed

Mazzucchelli, Trevor G; Hodges, Julie; Kane, Robert T; Sofronoff, Kate; Sanders, Matthew R; Einfeld, Stewart; Tonge, Bruce; Gray, Kylie M

2018-01-01

Children with a developmental disability are three to four times more likely than their typically developing peers of developing significant emotional and behavioural problems. There is strong evidence to suggest that individual biological and psychological factors interact with family functioning to precipitate and perpetuate these problems. This study examined the psychometric properties of a brief measure, the Parent and Family Adjustment Scales (PAFAS) for use with parents of children with a developmental disability. A sample of 914 parents of children (M=6.27years) with a developmental disability participated in the study. Disabilities included Autism Spectrum Disorder and Intellectual Disability RESULTS: A confirmatory factor analysis supported a 16-item, four factor model of PAFAS Parenting, and an 11-item, three factor model of PAFAS Family Adjustment. The Parenting Scale measures parental consistency, coercive practices, use of encouragement and the quality of parent-child relationship. The Family Adjustment Scale measures parental emotional adjustment and partner and family support in parenting. The current study indicated that the PAFAS demonstrates promise as a brief measure of multiple domains of family functioning important for families who have a child with a developmental disability. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept.

PubMed

Friedrich, D T; Sommer, F; Scheithauer, M O; Greve, J; Hoffmann, T K; Schuler, P J

2017-12-01

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

Theoretical modeling of a gas clearance phase regulation mechanism for a pneumatically-driven split-Stirling-cycle cryocooler

NASA Astrophysics Data System (ADS)

Zhang, Cun-quan; Zhong, Cheng

2015-03-01

The concept of a new type of pneumatically-driven split-Stirling-cycle cryocooler with clearance-phase-adjustor is proposed. In this implementation, the gap between the phase-adjusting part and the cylinder of the spring chamber is used, instead of dry friction acting on the pneumatically-driven rod to control motion damping of the displacer and to adjust the phase difference between the compression piston and displacer. It has the advantages of easy damping adjustment, low cost, and simplified manufacturing and assembly. A theoretical model has been established to simulate its dynamic performance. The linear compressor is modeled under adiabatic conditions, and the displacement of the compression piston is experimentally rectified. The working characteristics of the compressor motor and the principal losses of cooling, including regenerator inefficiency loss, solid conduction loss, shuttle loss, pump loss and radiation loss, are taken into account. The displacer motion was modeled as a single-degree-of-freedom (SDOF) forced system. A set of governing equations can be solved numerically to simulate the cooler's performance. The simulation is useful for understanding the physical processes occurring in the cooler and for predicting the cooler's performance.

Resolving model parameter values from carbon and nitrogen stock measurements in a wide range of tropical mature forests using nonlinear inversion and regression trees

USGS Publications Warehouse

Liu, S.; Anderson, P.; Zhou, G.; Kauffman, B.; Hughes, F.; Schimel, D.; Watson, Vicente; Tosi, Joseph

2008-01-01

Objectively assessing the performance of a model and deriving model parameter values from observations are critical and challenging in landscape to regional modeling. In this paper, we applied a nonlinear inversion technique to calibrate the ecosystem model CENTURY against carbon (C) and nitrogen (N) stock measurements collected from 39 mature tropical forest sites in seven life zones in Costa Rica. Net primary productivity from the Moderate-Resolution Imaging Spectroradiometer (MODIS), C and N stocks in aboveground live biomass, litter, coarse woody debris (CWD), and in soils were used to calibrate the model. To investigate the resolution of available observations on the number of adjustable parameters, inversion was performed using nine setups of adjustable parameters. Statistics including observation sensitivity, parameter correlation coefficient, parameter sensitivity, and parameter confidence limits were used to evaluate the information content of observations, resolution of model parameters, and overall model performance. Results indicated that soil organic carbon content, soil nitrogen content, and total aboveground biomass carbon had the highest information contents, while measurements of carbon in litter and nitrogen in CWD contributed little to the parameter estimation processes. The available information could resolve the values of 2-4 parameters. Adjusting just one parameter resulted in under-fitting and unacceptable model performance, while adjusting five parameters simultaneously led to over-fitting. Results further indicated that the MODIS NPP values were compressed as compared with the spatial variability of net primary production (NPP) values inferred from inverse modeling. Using inverse modeling to infer NPP and other sensitive model parameters from C and N stock observations provides an opportunity to utilize data collected by national to regional forest inventory systems to reduce the uncertainties in the carbon cycle and generate valuable databases to validate and improve MODIS NPP algorithms.

New arrows in the quiver for targeting care management: high-risk versus high-opportunity case identification.

PubMed

Bernstein, Richard H

2007-01-01

"Care management" purposefully obscures the distinctions between disease and case management and stresses their common features: action in the present to prevent adverse future outcomes and costs. It includes identifying a high-need population by referrals, screening, or data analysis, assessing those likely to benefit from interventions, intervening, evaluating the intervention, and adjusting interventions when needed. High-risk individuals can be identified using at least 9 techniques, from referrals and questionnaires to retrospective claims analysis and predictive models. Other than referrals, software based on the risk-adjustment methodology that we have adapted can incorporate all these methodologies. Because the risk adjustment employs extensive case mix and severity adjustment, it provides care managers with 3 innovative ways to identify not only high-risk individuals but also high-opportunity cases.

Effect of Adding McKenzie Syndrome, Centralization, Directional Preference, and Psychosocial Classification Variables to a Risk-Adjusted Model Predicting Functional Status Outcomes for Patients With Lumbar Impairments.

PubMed

Werneke, Mark W; Edmond, Susan; Deutscher, Daniel; Ward, Jason; Grigsby, David; Young, Michelle; McGill, Troy; McClenahan, Brian; Weinberg, Jon; Davidow, Amy L

2016-09-01

Study Design Retrospective cohort. Background Patient-classification subgroupings may be important prognostic factors explaining outcomes. Objectives To determine effects of adding classification variables (McKenzie syndrome and pain patterns, including centralization and directional preference; Symptom Checklist Back Pain Prediction Model [SCL BPPM]; and the Fear-Avoidance Beliefs Questionnaire subscales of work and physical activity) to a baseline risk-adjusted model predicting functional status (FS) outcomes. Methods Consecutive patients completed a battery of questionnaires that gathered information on 11 risk-adjustment variables. Physical therapists trained in Mechanical Diagnosis and Therapy methods classified each patient by McKenzie syndromes and pain pattern. Functional status was assessed at discharge by patient-reported outcomes. Only patients with complete data were included. Risk of selection bias was assessed. Prediction of discharge FS was assessed using linear stepwise regression models, allowing 13 variables to enter the model. Significant variables were retained in subsequent models. Model power (R(2)) and beta coefficients for model variables were estimated. Results Two thousand sixty-six patients with lumbar impairments were evaluated. Of those, 994 (48%), 10 (<1%), and 601 (29%) were excluded due to incomplete psychosocial data, McKenzie classification data, and missing FS at discharge, respectively. The final sample for analyses was 723 (35%). Overall R(2) for the baseline prediction FS model was 0.40. Adding classification variables to the baseline model did not result in significant increases in R(2). McKenzie syndrome or pain pattern explained 2.8% and 3.0% of the variance, respectively. When pain pattern and SCL BPPM were added simultaneously, overall model R(2) increased to 0.44. Although none of these increases in R(2) were significant, some classification variables were stronger predictors compared with some other variables included in the baseline model. Conclusion The small added prognostic capabilities identified when combining McKenzie or pain-pattern classifications with the SCL BPPM classification did not significantly improve prediction of FS outcomes in this study. Additional research is warranted to investigate the importance of classification variables compared with those used in the baseline model to maximize predictive power. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2016;46(9):726-741. Epub 31 Jul 2016. doi:10.2519/jospt.2016.6266.

Dietary saturated fat intake is inversely associated with bone density in humans: analysis of NHANES III.

PubMed

Corwin, Rebecca L; Hartman, Terryl J; Maczuga, Steven A; Graubard, Barry I

2006-01-01

Mounting evidence indicates that the amount and type of fat in the diet can have important effects on bone health. Most of this evidence is derived from animal studies. Of the few human studies that have been conducted, relatively small numbers of subjects and/or primarily female subjects were included. The present study assessed the relation of dietary fat to hip bone mineral density (BMD) in men and women using NHANES III data (n = 14,850). Multivariate models using SAS-callable SUDAAN were used to adjust for the sampling scheme. Models were adjusted for age, sex, weight, height, race, total energy and calcium intakes, smoking, and weight-bearing exercise. Data from women were further adjusted for use of hormone replacement therapy. Including dietary protein, vitamin C, and beta-carotene in the model did not influence the outcome. Analysis of covariance was used to generate mean BMD by quintile of total and saturated fat intake for 4 sex/age groups. Saturated fat intake was negatively associated with BMD at several hip sites. The greatest effects were seen among men < 50 y old (linear trend P = 0.004 for the femoral neck). For the femoral neck, adjusted mean BMD was 4.3% less among men with the highest compared with the lowest quintile of saturated fat intake (BMD, 95% CI: highest quintile: 0.922 g/cm2, 0.909-0.935; lowest quintile: 0.963 g/cm2, 95% CI: 0.950-0.976). These data indicate that BMD is negatively associated with saturated fat intake, and that men may be particularly vulnerable to these effects.

First Year Student Adjustment, Success, and Retention: Structural Models of Student Persistence Using Electronic Portfolios

ERIC Educational Resources Information Center

Sandler, Martin E.

2010-01-01

This study explores the deployment of electronic portfolios to a university-wide cohort of freshman undergraduates that included a subgroup of at-risk and lower academically prepared learners. Five evaluative dimensions based on persistence and engagement theory were included in the development of four assessment rubrics exploring goal clarity,…

Methods for detecting, quantifying, and adjusting for dissemination bias in meta-analysis are described.

PubMed

Mueller, Katharina Felicitas; Meerpohl, Joerg J; Briel, Matthias; Antes, Gerd; von Elm, Erik; Lang, Britta; Motschall, Edith; Schwarzer, Guido; Bassler, Dirk

2016-12-01

To systematically review methodological articles which focus on nonpublication of studies and to describe methods of detecting and/or quantifying and/or adjusting for dissemination in meta-analyses. To evaluate whether the methods have been applied to an empirical data set for which one can be reasonably confident that all studies conducted have been included. We systematically searched Medline, the Cochrane Library, and Web of Science, for methodological articles that describe at least one method of detecting and/or quantifying and/or adjusting for dissemination bias in meta-analyses. The literature search retrieved 2,224 records, of which we finally included 150 full-text articles. A great variety of methods to detect, quantify, or adjust for dissemination bias were described. Methods included graphical methods mainly based on funnel plot approaches, statistical methods, such as regression tests, selection models, sensitivity analyses, and a great number of more recent statistical approaches. Only few methods have been validated in empirical evaluations using unpublished studies obtained from regulators (Food and Drug Administration, European Medicines Agency). We present an overview of existing methods to detect, quantify, or adjust for dissemination bias. It remains difficult to advise which method should be used as they are all limited and their validity has rarely been assessed. Therefore, a thorough literature search remains crucial in systematic reviews, and further steps to increase the availability of all research results need to be taken. Copyright © 2016 Elsevier Inc. All rights reserved.

Beyond comorbidity: expanding the definition and measurement of complexity among older adults using administrative claims data.

PubMed

Chrischilles, Elizabeth; Schneider, Kathleen; Wilwert, June; Lessman, Gregory; O'Donnell, Brian; Gryzlak, Brian; Wright, Kara; Wallace, Robert

2014-03-01

Studies of patients with multiple chronic conditions using claims data are often missing important determinants of treatments and outcomes, such as function status and disease severity. We sought to identify and evaluate a class of function-related indicators (FRIs) from administrative claims data. The study cohort comprised US Medicare beneficiaries aged 65 years or older with Parts A and B fee-for-service and Part D coverage, with a hospitalization for acute myocardial infarction during 2007. Measures during the year before admission included the FRIs, demographics, conventional comorbidity measures, and prior hospitalization. Outcomes were receipt of cardiac catheterization during the index hospitalization and 12-month mortality. Model development used a random sample (n=72,056) with an equal sample for validation. In addition to prior cardiovascular conditions (85%), 40% had ≥1 comorbid condition, 30% were hospitalized in the prior 6 months, and 65% had ≥1 FRI [eg, delirium/dementia (22.7%), depression (16.7%), mobility limitation (16.1%), and chronic skin ulcers (12.6%)]. Including the FRIs improved mortality and cardiac catheterization prediction models (C-statistics 0.71 and 0.77, respectively). Patients with more cardiovascular conditions received less cardiac catheterization [minimally adjusted odds ratio (OR) 0.83; 95% confidence interval (CI), 0.82-0.83], as did patients with more comorbidities (minimally adjusted OR 0.70; 95% CI, 0.69-0.71), but this was attenuated by adjusting for functional status (fully adjusted OR for cardiovascular conditions 0.95; 95% CI, 0.94-0.96 and for comorbid conditions 0.94; 95% CI, 0.92-0.95). Claims data studies that include indicators of potentially diminished patient functional status better capture heterogeneity of patients with multiple chronic conditions.

42 CFR § 512.300 - Determination of episode quality-adjusted target prices and actual episode payments.

Code of Federal Regulations, 2010 CFR

2017-10-01

... PROGRAMS EPISODE PAYMENT MODEL Pricing and Payment § 512.300 Determination of episode quality-adjusted... historical episode payments. (iii) For the AMI model, quality-adjusted target prices for anchor MS-DRGs 246... 100 percent regional historical episode payments. (iv) For the CABG model, quality-adjusted target...

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder.

PubMed

Bauer, M; Glenn, T; Alda, M; Andreassen, O A; Angelopoulos, E; Ardau, R; Baethge, C; Bauer, R; Bellivier, F; Belmaker, R H; Berk, M; Bjella, T D; Bossini, L; Bersudsky, Y; Cheung, E Y W; Conell, J; Del Zompo, M; Dodd, S; Etain, B; Fagiolini, A; Frye, M A; Fountoulakis, K N; Garneau-Fournier, J; Gonzalez-Pinto, A; Harima, H; Hassel, S; Henry, C; Iacovides, A; Isometsä, E T; Kapczinski, F; Kliwicki, S; König, B; Krogh, R; Kunz, M; Lafer, B; Larsen, E R; Lewitzka, U; Lopez-Jaramillo, C; MacQueen, G; Manchia, M; Marsh, W; Martinez-Cengotitabengoa, M; Melle, I; Monteith, S; Morken, G; Munoz, R; Nery, F G; O'Donovan, C; Osher, Y; Pfennig, A; Quiroz, D; Ramesar, R; Rasgon, N; Reif, A; Ritter, P; Rybakowski, J K; Sagduyu, K; Scippa, A M; Severus, E; Simhandl, C; Stein, D J; Strejilevich, S; Hatim Sulaiman, A; Suominen, K; Tagata, H; Tatebayashi, Y; Torrent, C; Vieta, E; Viswanath, B; Wanchoo, M J; Zetin, M; Whybrow, P C

2015-01-01

Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database. The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared. There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups. These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Model-Based Economic Evaluation of Treatments for Depression: A Systematic Literature Review.

PubMed

Kolovos, Spyros; Bosmans, Judith E; Riper, Heleen; Chevreul, Karine; Coupé, Veerle M H; van Tulder, Maurits W

2017-09-01

An increasing number of model-based studies that evaluate the cost effectiveness of treatments for depression are being published. These studies have different characteristics and use different simulation methods. We aimed to systematically review model-based studies evaluating the cost effectiveness of treatments for depression and examine which modelling technique is most appropriate for simulating the natural course of depression. The literature search was conducted in the databases PubMed, EMBASE and PsycInfo between 1 January 2002 and 1 October 2016. Studies were eligible if they used a health economic model with quality-adjusted life-years or disability-adjusted life-years as an outcome measure. Data related to various methodological characteristics were extracted from the included studies. The available modelling techniques were evaluated based on 11 predefined criteria. This methodological review included 41 model-based studies, of which 21 used decision trees (DTs), 15 used cohort-based state-transition Markov models (CMMs), two used individual-based state-transition models (ISMs), and three used discrete-event simulation (DES) models. Just over half of the studies (54%) evaluated antidepressants compared with a control condition. The data sources, time horizons, cycle lengths, perspectives adopted and number of health states/events all varied widely between the included studies. DTs scored positively in four of the 11 criteria, CMMs in five, ISMs in six, and DES models in seven. There were substantial methodological differences between the studies. Since the individual history of each patient is important for the prognosis of depression, DES and ISM simulation methods may be more appropriate than the others for a pragmatic representation of the course of depression. However, direct comparisons between the available modelling techniques are necessary to yield firm conclusions.

Predicting the performance of a power amplifier using large-signal circuit simulations of an AlGaN/GaN HFET model

NASA Astrophysics Data System (ADS)

Bilbro, Griff L.; Hou, Danqiong; Yin, Hong; Trew, Robert J.

2009-02-01

We have quantitatively modeled the conduction current and charge storage of an HFET in terms its physical dimensions and material properties. For DC or small-signal RF operation, no adjustable parameters are necessary to predict the terminal characteristics of the device. Linear performance measures such as small-signal gain and input admittance can be predicted directly from the geometric structure and material properties assumed for the device design. We have validated our model at low-frequency against experimental I-V measurements and against two-dimensional device simulations. We discuss our recent extension of our model to include a larger class of electron velocity-field curves. We also discuss the recent reformulation of our model to facilitate its implementation in commercial large-signal high-frequency circuit simulators. Large signal RF operation is more complex. First, the highest CW microwave power is fundamentally bounded by a brief, reversible channel breakdown in each RF cycle. Second, the highest experimental measurements of efficiency, power, or linearity always require harmonic load pull and possibly also harmonic source pull. Presently, our model accounts for these facts with an adjustable breakdown voltage and with adjustable load impedances and source impedances for the fundamental frequency and its harmonics. This has allowed us to validate our model for large signal RF conditions by simultaneously fitting experimental measurements of output power, gain, and power added efficiency of real devices. We show that the resulting model can be used to compare alternative device designs in terms of their large signal performance, such as their output power at 1dB gain compression or their third order intercept points. In addition, the model provides insight into new device physics features enabled by the unprecedented current and voltage levels of AlGaN/GaN HFETs, including non-ohmic resistance in the source access regions and partial depletion of the 2DEG in the drain access region.

Meteorological adjustment of yearly mean values for air pollutant concentration comparison

NASA Technical Reports Server (NTRS)

Sidik, S. M.; Neustadter, H. E.

1976-01-01

Using multiple linear regression analysis, models which estimate mean concentrations of Total Suspended Particulate (TSP), sulfur dioxide, and nitrogen dioxide as a function of several meteorologic variables, two rough economic indicators, and a simple trend in time are studied. Meteorologic data were obtained and do not include inversion heights. The goodness of fit of the estimated models is partially reflected by the squared coefficient of multiple correlation which indicates that, at the various sampling stations, the models accounted for about 23 to 47 percent of the total variance of the observed TSP concentrations. If the resulting model equations are used in place of simple overall means of the observed concentrations, there is about a 20 percent improvement in either: (1) predicting mean concentrations for specified meteorological conditions; or (2) adjusting successive yearly averages to allow for comparisons devoid of meteorological effects. An application to source identification is presented using regression coefficients of wind velocity predictor variables.

Communication Efficacy and Couples’ Cancer Management: Applying a Dyadic Appraisal Model

PubMed Central

Magsamen-Conrad, Kate; Checton, Maria G.; Venetis, Maria K.; Greene, Kathryn

2014-01-01

The purpose of the present study was to apply Berg and Upchurch’s (2007) developmental-conceptual model to understand better how couples cope with cancer. Specifically, we hypothesized a dyadic appraisal model in which proximal factors (relational quality), dyadic appraisal (prognosis uncertainty), and dyadic coping (communication efficacy) predicted adjustment (cancer management). The study was cross-sectional and included 83 dyads in which one partner had been diagnosed with and/or treated for cancer. For both patients and partners, multilevel analyses using the actor-partner interdependence model (APIM) indicated that proximal contextual factors predicted dyadic appraisal and dyadic coping. Dyadic appraisal predicted dyadic coping, which then predicted dyadic adjustment. Patients’ confidence in their ability to talk about the cancer predicted their own cancer management. Partners’ confidence predicted their own and the patient’s ability to cope with cancer, which then predicted patients’ perceptions of their general health. Implications and future research are discussed. PMID:25983382

Communication Efficacy and Couples' Cancer Management: Applying a Dyadic Appraisal Model.

PubMed

Magsamen-Conrad, Kate; Checton, Maria G; Venetis, Maria K; Greene, Kathryn

2015-06-01

The purpose of the present study was to apply Berg and Upchurch's (2007) developmental-conceptual model to understand better how couples cope with cancer. Specifically, we hypothesized a dyadic appraisal model in which proximal factors (relational quality), dyadic appraisal (prognosis uncertainty), and dyadic coping (communication efficacy) predicted adjustment (cancer management). The study was cross-sectional and included 83 dyads in which one partner had been diagnosed with and/or treated for cancer. For both patients and partners, multilevel analyses using the actor-partner interdependence model (APIM) indicated that proximal contextual factors predicted dyadic appraisal and dyadic coping. Dyadic appraisal predicted dyadic coping, which then predicted dyadic adjustment. Patients' confidence in their ability to talk about the cancer predicted their own cancer management. Partners' confidence predicted their own and the patient's ability to cope with cancer, which then predicted patients' perceptions of their general health. Implications and future research are discussed.

The Cost-Effectiveness of Syphilis Screening Among Men Who Have Sex With Men: An Exploratory Modeling Analysis.

PubMed

Chesson, Harrell W; Kidd, Sarah; Bernstein, Kyle T; Fanfair, Robyn Neblett; Gift, Thomas L

2016-07-01

We adapted a published model to estimate the costs and benefits of screening men who have sex with men for syphilis, including the benefits of preventing syphilis-attributable human immunodeficiency virus. The cost per quality-adjusted life year gained by screening was

How to deal with climate change uncertainty in the planning of engineering systems

NASA Astrophysics Data System (ADS)

Spackova, Olga; Dittes, Beatrice; Straub, Daniel

2016-04-01

The effect of extreme events such as floods on the infrastructure and built environment is associated with significant uncertainties: These include the uncertain effect of climate change, uncertainty on extreme event frequency estimation due to limited historic data and imperfect models, and, not least, uncertainty on future socio-economic developments, which determine the damage potential. One option for dealing with these uncertainties is the use of adaptable (flexible) infrastructure that can easily be adjusted in the future without excessive costs. The challenge is in quantifying the value of adaptability and in finding the optimal sequence of decision. Is it worth to build a (potentially more expensive) adaptable system that can be adjusted in the future depending on the future conditions? Or is it more cost-effective to make a conservative design without counting with the possible future changes to the system? What is the optimal timing of the decision to build/adjust the system? We develop a quantitative decision-support framework for evaluation of alternative infrastructure designs under uncertainties, which: • probabilistically models the uncertain future (trough a Bayesian approach) • includes the adaptability of the systems (the costs of future changes) • takes into account the fact that future decisions will be made under uncertainty as well (using pre-posterior decision analysis) • allows to identify the optimal capacity and optimal timing to build/adjust the infrastructure. Application of the decision framework will be demonstrated on an example of flood mitigation planning in Bavaria.

Forecasting of foreign exchange rates of Taiwan’s major trading partners by novel nonlinear Grey Bernoulli model NGBM(1, 1)

NASA Astrophysics Data System (ADS)

Chen, Chun-I.; Chen, Hong Long; Chen, Shuo-Pei

2008-08-01

The traditional Grey Model is easy to understand and simple to calculate, with satisfactory accuracy, but it is also lack of flexibility to adjust the model to acquire higher forecasting precision. This research studies feasibility and effectiveness of a novel Grey model together with the concept of the Bernoulli differential equation in ordinary differential equation. In this research, the author names this newly proposed model as Nonlinear Grey Bernoulli Model (NGBM). The NGBM is nonlinear differential equation with power index n. By controlling n, the curvature of the solution curve could be adjusted to fit the result of one time accumulated generating operation (1-AGO) of raw data. One extreme case from Grey system textbook is studied by NGBM, and two published articles are chosen for practical tests of NGBM. The results prove the novel NGBM is feasible and efficient. Finally, NGBM is used to forecast 2005 foreign exchange rates of twelve Taiwan major trading partners, including Taiwan.

Modelling the impact of new patient visits on risk adjusted access at 2 clinics.

PubMed

Kolber, Michael A; Rueda, Germán; Sory, John B

2018-06-01

To evaluate the effect new outpatient clinic visits has on the availability of follow-up visits for established patients when patient visit frequency is risk adjusted. Diagnosis codes for patients from 2 Internal Medicine Clinics were extracted through billing data. The HHS-HCC risk adjusted scores for each clinic were determined based upon the average of all clinic practitioners' profiles. These scores were then used to project encounter frequencies for established patients, and for new patients entering the clinic based on risk and time of entry into the clinics. A distinct mean risk frequency distribution for physicians in each clinic could be defined providing model parameters. Within the model, follow-up visit utilization at the highest risk adjusted visit frequencies would require more follow-up slots than currently available when new patient no-show rates and annual patient loss are included. Patients seen at an intermediate or lower visit risk adjusted frequency could be accommodated when new patient no-show rates and annual patient clinic loss are considered. Value-based care is driven by control of cost while maintaining quality of care. In order to control cost, there has been a drive to increase visit frequency in primary care for those patients at increased risk. Adding new patients to primary care clinics limits the availability of follow-up slots that accrue over time for those at highest risk, thereby limiting disease and, potentially, cost control. If frequency of established care visits can be reduced by improved disease control, closing the practice to new patients, hiring health care extenders, or providing non-face to face care models then quality and cost of care may be improved. © 2018 John Wiley & Sons, Ltd.

Evaluating changes in matrix based, recovery-adjusted concentrations in paired data for pesticides in groundwater

USGS Publications Warehouse

Zimmerman, Tammy M.; Breen, Kevin J.

2012-01-01

Pesticide concentration data for waters from selected carbonate-rock aquifers in agricultural areas of Pennsylvania were collected in 1993–2009 for occurrence and distribution assessments. A set of 30 wells was visited once in 1993–1995 and again in 2008–2009 to assess concentration changes. The data include censored matched pairs (nondetections of a compound in one or both samples of a pair). A potentially improved approach for assessing concentration changes is presented where (i) concentrations are adjusted with models of matrix-spike recovery and (ii) area-wide temporal change is tested by use of the paired Prentice-Wilcoxon (PPW) statistical test. The PPW results for atrazine, simazine, metolachlor, prometon, and an atrazine degradate, deethylatrazine (DEA), are compared using recovery-adjusted and unadjusted concentrations. Results for adjusted compared with unadjusted concentrations in 2008–2009 compared with 1993–1995 were similar for atrazine and simazine (significant decrease; 95% confidence level) and metolachlor (no change) but differed for DEA (adjusted, decrease; unadjusted, increase) and prometon (adjusted, decrease; unadjusted, no change). The PPW results were different on recovery-adjusted compared with unadjusted concentrations. Not accounting for variability in recovery can mask a true change, misidentify a change when no true change exists, or assign a direction opposite of the true change in concentration that resulted from matrix influences on extraction and laboratory method performance. However, matrix-based models of recovery derived from a laboratory performance dataset from multiple studies for national assessment, as used herein, rather than time- and study-specific recoveries may introduce uncertainty in recovery adjustments for individual samples that should be considered in assessing change.

Using Remote Sensing and High-Resolution Digital Elevation Models to Identify Potential Erosional Hotspots Along River Channels During High Discharge Storm Events

NASA Astrophysics Data System (ADS)

Orland, E. D.; Amidon, W. H.

2017-12-01

As global warming intensifies, large precipitation events and associated floods are becoming increasingly common. Channel adjustments during floods can occur by both erosion and deposition of sediment, often damaging infrastructure in the process. There is thus a need for predictive models that can help managers identify river reaches that are most prone to adjustment during storms. Because rivers in post-glacial landscapes often flow over a mixture of bedrock and alluvial substrates, the identification of bedrock vs. alluvial channel reaches is an important first step in predicting vulnerability to channel adjustment during flood events, especially because bedrock channels are unlikely to adjust significantly, even during floods. This study develops a semi-automated approach to predicting channel substrate using a high-resolution LiDAR-derived digital elevation model (DEM). The study area is the Middlebury River in Middlebury, VT-a well-studied watershed with a wide variety of channel substrates, including reaches with documented channel adjustments during recent flooding events. Multiple metrics were considered for reference—such as channel width and drainage area—but the study utilized channel slope as a key parameter for identifying morphological variations within the Middlebury River. Using data extracted from the DEM, a power law was fit to selected slope and drainage area values for each branch in order to model idealized slope-drainage area relationships, which were then compared with measured slope-drainage area relationships. Differences in measured slope minus predicted slope (called delta-slope) are shown to help predict river channel substrate. Compared with field observations, higher delta-slope values correlate with more stable, boulder rich channels or bedrock gorges; conversely the lowest delta-slope values correlate with flat, sediment rich alluvial channels. The delta-slope metric thus serves as a reliable first-order predictor of channel substrate in the Middlebury River, which in turn can be used to help identify local reaches that are most vulnerable to channel adjustment during large flood events.

Immunodeficiency, AIDS-related pneumonia, and risk of lung cancer among HIV-infected individuals.

PubMed

Marcus, Julia L; Leyden, Wendy A; Chao, Chun R; Horberg, Michael A; Klein, Daniel B; Quesenberry, Charles P; Towner, William J; Silverberg, Michael J

2017-04-24

The objective is to clarify the role of immunodeficiency and pneumonia in elevated lung cancer risk among HIV-infected individuals. Cohort study of HIV-infected and HIV-uninfected adults in a large integrated healthcare system in California during 1996-2011. We used Poisson models to obtain rate ratios for lung cancer associated with HIV infection, overall and stratified by recent CD4 cells/μl (HIV-uninfected as reference group), with χ tests for trends across CD4 strata. Fully adjusted models included demographics, cancer risk factors (smoking, drug/alcohol abuse, overweight/obesity), and prior pneumonia. Among 24 768 HIV-infected and 257 600 HIV-uninfected individuals, the lung cancer rate per 100 000 person-years was 66 (n = 80 events) for HIV-infected and 33 (n = 506 events) for HIV-uninfected individuals [rate ratio 2.0, 95% confidence interval (CI): 1.7-2.2]. Overall, HIV-infected individuals were at increased risk of lung cancer after adjustment for demographics and cancer risk factors (rate ratio 1.4, 95% CI: 1.1-1.7), but not after additional adjustment for pneumonia (rate ratio 1.2, 95% CI: 0.9-1.6). Lower CD4 cell counts were associated with higher risk of lung cancer in unadjusted and demographics-adjusted models (P < 0.001 for all), but this trend did not remain after adjustment for cancer risk factors and pneumonia. Compared with HIV-uninfected individuals, HIV-infected individuals with CD4 less than 200 cells/μl were not at increased risk of lung cancer in fully adjusted models. The increased lung cancer risk among HIV patients is attributable to differences in demographics, risk factors such as smoking, and history of pneumonia. Immunodeficiency does not appear to have an independent effect on lung cancer risk.

Ocean Turbulence. Paper 2; One-Point Closure Model Momentum, Heat and Salt Vertical Diffusivities in the Presence of Shear

NASA Technical Reports Server (NTRS)

Canuto, V. M.; Howard, A.; Cheng, Y.; Dubovikov, M. S.

1999-01-01

We develop and test a 1-point closure turbulence model with the following features: 1) we include the salinity field and derive the expression for the vertical turbulent diffusivities of momentum K(sub m) , heat K(sub h) and salt K(sub s) as a function of two stability parameters: the Richardson number R(sub i) (stratification vs. shear) and the Turner number R(sub rho) (salinity gradient vs. temperature gradient). 2) to describe turbulent mixing below the mixed layer (ML), all previous models have adopted three adjustable "background diffusivities" for momentum, heat and salt. We propose a model that avoids such adjustable diffusivities. We assume that below the ML, the three diffusivities have the same functional dependence on R( sub i) and R(sub rho) as derived from the turbulence model. However, in order to compute R(sub i) below the ML, we use data of vertical shear due to wave-breaking.measured by Gargett et al. The procedure frees the model from adjustable background diffusivities and indeed we employ the same model throughout the entire vertical extent of the ocean. 3) in the local model, the turbulent diffusivities K(sub m,h,s) are given as analytical functions of R(sub i) and R(sub rho). 5) the model is used in an O-GCM and several results are presented to exhibit the effect of double diffusion processes. 6) the code is available upon request.

Is the maturity of hospitals' quality improvement systems associated with measures of quality and patient safety?

PubMed Central

2011-01-01

Background Previous research addressed the development of a classification scheme for quality improvement systems in European hospitals. In this study we explore associations between the 'maturity' of the hospitals' quality improvement system and clinical outcomes. Methods The maturity classification scheme was developed based on survey results from 389 hospitals in eight European countries. We matched the hospitals from the Spanish sample (113 hospitals) with those hospitals participating in a nation-wide, voluntary hospital performance initiative. We then compared sample distributions and explored associations between the 'maturity' of the hospitals' quality improvement system and a range of composite outcomes measures, such as adjusted hospital-wide mortality, -readmission, -complication and -length of stay indices. Statistical analysis includes bivariate correlations for parametrically and non-parametrically distributed data, multiple robust regression models and bootstrapping techniques to obtain confidence-intervals for the correlation and regression estimates. Results Overall, 43 hospitals were included. Compared to the original sample of 113, this sample was characterized by a higher representation of university hospitals. Maturity of the quality improvement system was similar, although the matched sample showed less variability. Analysis of associations between the quality improvement system and hospital-wide outcomes suggests significant correlations for the indicator adjusted hospital complications, borderline significance for adjusted hospital readmissions and non-significance for the adjusted hospital mortality and length of stay indicators. These results are confirmed by the bootstrap estimates of the robust regression model after adjusting for hospital characteristics. Conclusions We assessed associations between hospitals' quality improvement systems and clinical outcomes. From this data it seems that having a more developed quality improvement system is associated with lower rates of adjusted hospital complications. A number of methodological and logistic hurdles remain to link hospital quality improvement systems to outcomes. Further research should aim at identifying the latent dimensions of quality improvement systems that predict quality and safety outcomes. Such research would add pertinent knowledge regarding the implementation of organizational strategies related with quality of care outcomes. PMID:22185479

Husbands’ perceptions of their wives’ breast cancer coping efficacy: testing congruence models of adjustment

PubMed Central

Martinez Sanchez, MaryAnn

2018-01-01

Introduction Recent reviews have reinforced the notion that having a supportive spouse can help with the process of coping with and adjusting to cancer. Congruence between spouses’ perspectives has been proposed as one mechanism in that process, yet alternative models of congruence have not been examined closely. This study assessed alternative models of congruence in perceptions of coping and their mediating effects on adjustment to breast cancer. Methods Seventy-two women in treatment for breast cancer and their husbands completed measures of marital adjustment, self-efficacy for coping, and adjustment to cancer. Karnofsky Performance Status was obtained from medical records. Wives completed a measure of self-efficacy for coping (wives’ ratings of self-efficacy for coping [WSEC]) and husbands completed a measure of self-efficacy for coping (husbands’ ratings of wives’ self-efficacy for coping [HSEC]) based on their perceptions of their wives’ coping efficacy. Results Interestingly, the correlation between WSEC and HSEC was only 0.207; thus, they are relatively independent perspectives. The following three models were tested to determine the nature of the relationship between WSEC and HSEC: discrepancy model (WSEC − HSEC), additive model (WSEC + HSEC), and multiplicative model (WSEC × HSEC). The discrepancy model was not related to wives’ adjustment; however, the additive (B=0.205, P<0.001) and multiplicative (B=0.001, P<0.001) models were significantly related to wives’ adjustment. Also, the additive model mediated the relationship between performance status and adjustment. Discussion Husbands’ perception of their wives’ coping efficacy contributed marginally to their wives’ adjustment, and the combination of WSEC and HSEC mediated the relationship between functional status and wives’ adjustment, thus positively impacting wives’ adjustment to cancer. Future research is needed to determine the quality of the differences between HSEC and WSEC in order to develop interventions to optimize the impact of these two relatively independent perspectives on cancer outcomes. PMID:29491720

Husbands' perceptions of their wives' breast cancer coping efficacy: testing congruence models of adjustment.

PubMed

Merluzzi, Thomas V; Martinez Sanchez, MaryAnn

2018-01-01

Recent reviews have reinforced the notion that having a supportive spouse can help with the process of coping with and adjusting to cancer. Congruence between spouses' perspectives has been proposed as one mechanism in that process, yet alternative models of congruence have not been examined closely. This study assessed alternative models of congruence in perceptions of coping and their mediating effects on adjustment to breast cancer. Seventy-two women in treatment for breast cancer and their husbands completed measures of marital adjustment, self-efficacy for coping, and adjustment to cancer. Karnofsky Performance Status was obtained from medical records. Wives completed a measure of self-efficacy for coping (wives' ratings of self-efficacy for coping [WSEC]) and husbands completed a measure of self-efficacy for coping (husbands' ratings of wives' self-efficacy for coping [HSEC]) based on their perceptions of their wives' coping efficacy. Interestingly, the correlation between WSEC and HSEC was only 0.207; thus, they are relatively independent perspectives. The following three models were tested to determine the nature of the relationship between WSEC and HSEC: discrepancy model (WSEC - HSEC), additive model (WSEC + HSEC), and multiplicative model (WSEC × HSEC). The discrepancy model was not related to wives' adjustment; however, the additive ( B =0.205, P <0.001) and multiplicative ( B =0.001, P <0.001) models were significantly related to wives' adjustment. Also, the additive model mediated the relationship between performance status and adjustment. Husbands' perception of their wives' coping efficacy contributed marginally to their wives' adjustment, and the combination of WSEC and HSEC mediated the relationship between functional status and wives' adjustment, thus positively impacting wives' adjustment to cancer. Future research is needed to determine the quality of the differences between HSEC and WSEC in order to develop interventions to optimize the impact of these two relatively independent perspectives on cancer outcomes.

Disaster Hits Home: A Model of Displaced Family Adjustment after Hurricane Katrina

ERIC Educational Resources Information Center

Peek, Lori; Morrissey, Bridget; Marlatt, Holly

2011-01-01

The authors explored individual and family adjustment processes among parents (n = 30) and children (n = 55) who were displaced to Colorado after Hurricane Katrina. Drawing on in-depth interviews with 23 families, this article offers an inductive model of displaced family adjustment. Four stages of family adjustment are presented in the model: (a)…

Simulation analysis of an integrated model for dynamic cellular manufacturing system

NASA Astrophysics Data System (ADS)

Hao, Chunfeng; Luan, Shichao; Kong, Jili

2017-05-01

Application of dynamic cellular manufacturing system (DCMS) is a well-known strategy to improve manufacturing efficiency in the production environment with high variety and low volume of production. Often, neither the trade-off of inter and intra-cell material movements nor the trade-off of hiring and firing of operators are examined in details. This paper presents simulation results of an integrated mixed-integer model including sensitivity analysis for several numerical examples. The comprehensive model includes cell formation, inter and intracellular materials handling, inventory and backorder holding, operator assignment (including resource adjustment) and flexible production routing. The model considers multi-production planning with flexible resources (machines and operators) where each period has different demands. The results verify the validity and sensitivity of the proposed model using a genetic algorithm.

Environmental Chemicals in Urine and Blood: Improving Methods for Creatinine and Lipid Adjustment

PubMed Central

O’Brien, Katie M.; Upson, Kristen; Cook, Nancy R.; Weinberg, Clarice R.

2015-01-01

Background Investigators measuring exposure biomarkers in urine typically adjust for creatinine to account for dilution-dependent sample variation in urine concentrations. Similarly, it is standard to adjust for serum lipids when measuring lipophilic chemicals in serum. However, there is controversy regarding the best approach, and existing methods may not effectively correct for measurement error. Objectives We compared adjustment methods, including novel approaches, using simulated case–control data. Methods Using a directed acyclic graph framework, we defined six causal scenarios for epidemiologic studies of environmental chemicals measured in urine or serum. The scenarios include variables known to influence creatinine (e.g., age and hydration) or serum lipid levels (e.g., body mass index and recent fat intake). Over a range of true effect sizes, we analyzed each scenario using seven adjustment approaches and estimated the corresponding bias and confidence interval coverage across 1,000 simulated studies. Results For urinary biomarker measurements, our novel method, which incorporates both covariate-adjusted standardization and the inclusion of creatinine as a covariate in the regression model, had low bias and possessed 95% confidence interval coverage of nearly 95% for most simulated scenarios. For serum biomarker measurements, a similar approach involving standardization plus serum lipid level adjustment generally performed well. Conclusions To control measurement error bias caused by variations in serum lipids or by urinary diluteness, we recommend improved methods for standardizing exposure concentrations across individuals. Citation O’Brien KM, Upson K, Cook NR, Weinberg CR. 2016. Environmental chemicals in urine and blood: improving methods for creatinine and lipid adjustment. Environ Health Perspect 124:220–227; http://dx.doi.org/10.1289/ehp.1509693 PMID:26219104

Genetic value of herd life adjusted for milk production.

PubMed

Allaire, F R; Gibson, J P

1992-05-01

Cow herd life adjusted for lactational milk production was investigated as a genetic trait in the breeding objective. Under a simple model, the relative economic weight of milk to adjusted herd life on a per genetic standard deviation basis was equal to CVY/dCVL where CVY and CVL are the genetic coefficients of variation of milk production and adjusted herd life, respectively, and d is the depreciation per year per cow divided by the total fixed costs per year per cow. The relative economic value of milk to adjusted herd life at the prices and parameters for North America was about 3.2. An increase of 100-kg milk was equivalent to 2.2 mo of adjusted herd life. Three to 7% lower economic gain is expected when only improved milk production is sought compared with a breeding objective that included both production and adjusted herd life for relative value changed +/- 20%. A favorable economic gain to cost ratio probably exists for herd life used as a genetic trait to supplement milk in the breeding objective. Cow survival records are inexpensive, and herd life evaluations from such records may not extend the generation interval when such an evaluation is used in bull sire selection.

An improved canopy wind model for predicting wind adjustment factors and wildland fire behavior

Treesearch

W. J. Massman; J. M. Forthofer; M. A. Finney

2017-01-01

The ability to rapidly estimate wind speed beneath a forest canopy or near the ground surface in any vegetation is critical to practical wildland fire behavior models. The common metric of this wind speed is the "mid-flame" wind speed, UMF. However, the existing approach for estimating UMF has some significant shortcomings. These include the assumptions that...

Risk Transfer Formula for Individual and Small Group Markets Under the Affordable Care Act

PubMed Central

Pope, Gregory C; Bachofer, Henry; Pearlman, Andrew; Kautter, John; Hunter, Elizabeth; Miller, Daniel; Keenan, Patricia

2014-01-01

The Affordable Care Act provides for a program of risk adjustment in the individual and small group health insurance markets in 2014 as Marketplaces are implemented and new market reforms take effect. The purpose of risk adjustment is to lessen or eliminate the influence of risk selection on the premiums that plans charge. The risk adjustment methodology includes the risk adjustment model and the risk transfer formula. This article is the third of three in this issue of the Medicare & Medicaid Research Review that describe the ACA risk adjustment methodology and focuses on the risk transfer formula. In our first companion article, we discussed the key issues and choices in developing the methodology. In our second companion paper, we described the risk adjustment model that is used to calculate risk scores. In this article we present the risk transfer formula. We first describe how the plan risk score is combined with factors for the plan allowable premium rating, actuarial value, induced demand, geographic cost, and the statewide average premium in a formula that calculates transfers among plans. We then show how each plan factor is determined, as well as how the factors relate to each other in the risk transfer formula. The goal of risk transfers is to offset the effects of risk selection on plan costs while preserving premium differences due to factors such as actuarial value differences. Illustrative numerical simulations show the risk transfer formula operating as anticipated in hypothetical scenarios. PMID:25352994

Risk-adjusted Outcomes of Clinically Relevant Pancreatic Fistula Following Pancreatoduodenectomy: A Model for Performance Evaluation.

PubMed

McMillan, Matthew T; Soi, Sameer; Asbun, Horacio J; Ball, Chad G; Bassi, Claudio; Beane, Joal D; Behrman, Stephen W; Berger, Adam C; Bloomston, Mark; Callery, Mark P; Christein, John D; Dixon, Elijah; Drebin, Jeffrey A; Castillo, Carlos Fernandez-Del; Fisher, William E; Fong, Zhi Ven; House, Michael G; Hughes, Steven J; Kent, Tara S; Kunstman, John W; Malleo, Giuseppe; Miller, Benjamin C; Salem, Ronald R; Soares, Kevin; Valero, Vicente; Wolfgang, Christopher L; Vollmer, Charles M

2016-08-01

To evaluate surgical performance in pancreatoduodenectomy using clinically relevant postoperative pancreatic fistula (CR-POPF) occurrence as a quality indicator. Accurate assessment of surgeon and institutional performance requires (1) standardized definitions for the outcome of interest and (2) a comprehensive risk-adjustment process to control for differences in patient risk. This multinational, retrospective study of 4301 pancreatoduodenectomies involved 55 surgeons at 15 institutions. Risk for CR-POPF was assessed using the previously validated Fistula Risk Score, and pancreatic fistulas were stratified by International Study Group criteria. CR-POPF variability was evaluated and hierarchical regression analysis assessed individual surgeon and institutional performance. There was considerable variability in both CR-POPF risk and occurrence. Factors increasing the risk for CR-POPF development included increasing Fistula Risk Score (odds ratio 1.49 per point, P < 0.00001) and octreotide (odds ratio 3.30, P < 0.00001). When adjusting for risk, performance outliers were identified at the surgeon and institutional levels. Of the top 10 surgeons (≥15 cases) for nonrisk-adjusted performance, only 6 remained in this high-performing category following risk adjustment. This analysis of pancreatic fistulas following pancreatoduodenectomy demonstrates considerable variability in both the risk and occurrence of CR-POPF among surgeons and institutions. Disparities in patient risk between providers reinforce the need for comprehensive, risk-adjusted modeling when assessing performance based on procedure-specific complications. Furthermore, beyond inherent patient risk factors, surgical decision-making influences fistula outcomes.

[Effect of obesity intervention with socio-ecological model on anthropometric measurements of children and adolescents].

PubMed

Cui, Xin-yue; Chen, Tian-jiao; Ma, Jun

2015-06-18

To study whether the socio-ecological model based on "student-school-family" three-level strategy is effective in obesity prevention. A total of 3 175 students aged 7 to 18 from 16 schools (4 urban primary schools, 4 rural primary schools, 4 urban secondary schools and 4 rural secondary schools, of which 2 intervention schools were selected, respectively) were recruited by stratified cluster sampling method. A three-month intervention using "student-school-family" socio-ecological model was conducted through health education and environment improvement. The intervention contents included knowledge on obesity, healthy diet and physical activities. Their anthropometric indexes were recorded. The intervention prevented obesity (OR=1.12, P<0.05), and was effective in waist circumference (WC) and waist-hip ratio (WHR) (adjusted difference=0.63, 0.02, P<0.05). WC and WHR were reduced in girls (adjusted difference=0.52 & 0.02, P<0.05), and obesity was prevented in girls (OR=1.18, P<0.05). WC and WHR were reduced in boys (adjusted difference=0.73, 0.01, P<0.05). WHR were reduced in urban areas (adjusted difference=0.01, P<0.05). WC and WHR were reduced (adjusted difference=1.05, 0.02, P<0.05) and obesity was prevented (OR=1.18, P<0.05) in rural areas. WHR were reduced (adjusted difference=0.01, P<0.05) and obesity was prevented (OR=1.21, P<0.05) in primary schools. WHR were reduced in secondary schools (adjusted difference=0.02, P<0.05).The intervention effect was better in girls than in boys, in rural areas than in urban areas, and in primary schools than in secondary schools. The overweight and obesity prevalence went down after the intervention (χ2=11.01, P<0.01). Intervention strategy is effective in central obesity indexes such as WC and WHR, and it can be used widely.

Overcoming bias in estimating the volume-outcome relationship.

PubMed

Tsai, Alexander C; Votruba, Mark; Bridges, John F P; Cebul, Randall D

2006-02-01

To examine the effect of hospital volume on 30-day mortality for patients with congestive heart failure (CHF) using administrative and clinical data in conventional regression and instrumental variables (IV) estimation models. The primary data consisted of longitudinal information on comorbid conditions, vital signs, clinical status, and laboratory test results for 21,555 Medicare-insured patients aged 65 years and older hospitalized for CHF in northeast Ohio in 1991-1997. The patient was the primary unit of analysis. We fit a linear probability model to the data to assess the effects of hospital volume on patient mortality within 30 days of admission. Both administrative and clinical data elements were included for risk adjustment. Linear distances between patients and hospitals were used to construct the instrument, which was then used to assess the endogeneity of hospital volume. When only administrative data elements were included in the risk adjustment model, the estimated volume-outcome effect was statistically significant (p=.029) but small in magnitude. The estimate was markedly attenuated in magnitude and statistical significance when clinical data were added to the model as risk adjusters (p=.39). IV estimation shifted the estimate in a direction consistent with selective referral, but we were unable to reject the consistency of the linear probability estimates. Use of only administrative data for volume-outcomes research may generate spurious findings. The IV analysis further suggests that conventional estimates of the volume-outcome relationship may be contaminated by selective referral effects. Taken together, our results suggest that efforts to concentrate hospital-based CHF care in high-volume hospitals may not reduce mortality among elderly patients.

Traveling waves in an optimal velocity model of freeway traffic.

PubMed

Berg, P; Woods, A

2001-03-01

Car-following models provide both a tool to describe traffic flow and algorithms for autonomous cruise control systems. Recently developed optimal velocity models contain a relaxation term that assigns a desirable speed to each headway and a response time over which drivers adjust to optimal velocity conditions. These models predict traffic breakdown phenomena analogous to real traffic instabilities. In order to deepen our understanding of these models, in this paper, we examine the transition from a linear stable stream of cars of one headway into a linear stable stream of a second headway. Numerical results of the governing equations identify a range of transition phenomena, including monotonic and oscillating travelling waves and a time- dependent dispersive adjustment wave. However, for certain conditions, we find that the adjustment takes the form of a nonlinear traveling wave from the upstream headway to a third, intermediate headway, followed by either another traveling wave or a dispersive wave further downstream matching the downstream headway. This intermediate value of the headway is selected such that the nonlinear traveling wave is the fastest stable traveling wave which is observed to develop in the numerical calculations. The development of these nonlinear waves, connecting linear stable flows of two different headways, is somewhat reminiscent of stop-start waves in congested flow on freeways. The different types of adjustments are classified in a phase diagram depending on the upstream and downstream headway and the response time of the model. The results have profound consequences for autonomous cruise control systems. For an autocade of both identical and different vehicles, the control system itself may trigger formations of nonlinear, steep wave transitions. Further information is available [Y. Sugiyama, Traffic and Granular Flow (World Scientific, Singapore, 1995), p. 137].

Traveling waves in an optimal velocity model of freeway traffic

NASA Astrophysics Data System (ADS)

Berg, Peter; Woods, Andrew

2001-03-01

Car-following models provide both a tool to describe traffic flow and algorithms for autonomous cruise control systems. Recently developed optimal velocity models contain a relaxation term that assigns a desirable speed to each headway and a response time over which drivers adjust to optimal velocity conditions. These models predict traffic breakdown phenomena analogous to real traffic instabilities. In order to deepen our understanding of these models, in this paper, we examine the transition from a linear stable stream of cars of one headway into a linear stable stream of a second headway. Numerical results of the governing equations identify a range of transition phenomena, including monotonic and oscillating travelling waves and a time- dependent dispersive adjustment wave. However, for certain conditions, we find that the adjustment takes the form of a nonlinear traveling wave from the upstream headway to a third, intermediate headway, followed by either another traveling wave or a dispersive wave further downstream matching the downstream headway. This intermediate value of the headway is selected such that the nonlinear traveling wave is the fastest stable traveling wave which is observed to develop in the numerical calculations. The development of these nonlinear waves, connecting linear stable flows of two different headways, is somewhat reminiscent of stop-start waves in congested flow on freeways. The different types of adjustments are classified in a phase diagram depending on the upstream and downstream headway and the response time of the model. The results have profound consequences for autonomous cruise control systems. For an autocade of both identical and different vehicles, the control system itself may trigger formations of nonlinear, steep wave transitions. Further information is available [Y. Sugiyama, Traffic and Granular Flow (World Scientific, Singapore, 1995), p. 137].

CMAQ predictions of tropospheric ozone in the U.S. southwest: influence of lateral boundary and synoptic conditions.

PubMed

Shi, Chune; Fernando, H J S; Hyde, Peter

2012-02-01

Phoenix, Arizona, has been an ozone nonattainment area for the past several years and it remains so. Mitigation strategies call for improved modeling methodologies as well as understanding of ozone formation and destruction mechanisms during seasons of high ozone events. To this end, the efficacy of lateral boundary conditions (LBCs) based on satellite measurements (adjusted-LBCs) was investigated, vis-à-vis the default-LBCs, for improving the predictions of Models-3/CMAQ photochemical air quality modeling system. The model evaluations were conducted using hourly ground-level ozone and NO(2) concentrations as well as tropospheric NO(2) columns and ozone concentrations in the middle to upper troposphere, with the 'design' periods being June and July of 2006. Both included high ozone episodes, but the June (pre-monsoon) period was characterized by local thermal circulation whereas the July (monsoon) period by synoptic influence. Overall, improved simulations were noted for adjusted-LBC runs for ozone concentrations both at the ground-level and in the middle to upper troposphere, based on EPA-recommended model performance metrics. The probability of detection (POD) of ozone exceedances (>75ppb, 8-h averages) for the entire domain increased from 20.8% for the default-LBC run to 33.7% for the adjusted-LBC run. A process analysis of modeling results revealed that ozone within PBL during bulk of the pre-monsoon season is contributed by local photochemistry and vertical advection, while the contributions of horizontal and vertical advections are comparable in the monsoon season. The process analysis with adjusted-LBC runs confirms the contributions of vertical advection to episodic high ozone days, and hence elucidates the importance of improving predictability of upper levels with improved LBCs. Copyright © 2011 Elsevier B.V. All rights reserved.

Parenting and adolescents' psychological adjustment: Longitudinal moderation by adolescents' genetic sensitivity.

PubMed

Stocker, Clare M; Masarik, April S; Widaman, Keith F; Reeb, Ben T; Boardman, Jason D; Smolen, Andrew; Neppl, Tricia K; Conger, Katherine J

2017-10-01

We examined whether adolescents' genetic sensitivity, measured by a polygenic index score, moderated the longitudinal associations between parenting and adolescents' psychological adjustment. The sample included 323 mothers, fathers, and adolescents (177 female, 146 male; Time 1 [T1] average age = 12.61 years, SD = 0.54 years; Time 2 [T2] average age = 13.59 years, SD = 0.59 years). Parents' warmth and hostility were rated by trained, independent observers using videotapes of family discussions. Adolescents reported their symptoms of anxiety, depressed mood, and hostility at T1 and T2. The results from autoregressive linear regression models showed that adolescents' genetic sensitivity moderated associations between observations of both mothers' and fathers' T1 parenting and adolescents' T2 composite maladjustment, depression, anxiety, and hostility. Compared to adolescents with low genetic sensitivity, adolescents with high genetic sensitivity had worse adjustment outcomes when parenting was low on warmth and high on hostility. When parenting was characterized by high warmth and low hostility, adolescents with high genetic sensitivity had better adjustment outcomes than their counterparts with low genetic sensitivity. The results support the differential susceptibility model and highlight the complex ways that genes and environment interact to influence development.

Kuk's Model Adjusted for Protection and Efficiency

ERIC Educational Resources Information Center

Su, Shu-Ching; Sedory, Stephen A.; Singh, Sarjinder

2015-01-01

In this article, we adjust the Kuk randomized response model for collecting information on a sensitive characteristic for increased protection and efficiency by making use of forced "yes" and forced "no" responses. We first describe Kuk's model and then the proposed adjustment to Kuk's model. Next, by means of a simulation…

Robust crop and weed segmentation under uncontrolled outdoor illumination

USDA-ARS?s Scientific Manuscript database

A new machine vision for weed detection was developed from RGB color model images. Processes included in the algorithm for the detection were excessive green conversion, threshold value computation by statistical analysis, adaptive image segmentation by adjusting the threshold value, median filter, ...

40 CFR 86.094-25 - Maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sensors (including oxygen sensor if installed) and actuators. (D) Exhaust gas recirculation system..., and for 1985 and Later Model Year New Gasoline Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas... trucks and heavy-duty engines, the adjustment, cleaning, repair, or replacement of the oxygen sensor...

40 CFR 86.094-25 - Maintenance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sensors (including oxygen sensor if installed) and actuators. (D) Exhaust gas recirculation system..., and for 1985 and Later Model Year New Gasoline Fueled, Natural Gas-Fueled, Liquefied Petroleum Gas... trucks and heavy-duty engines, the adjustment, cleaning, repair, or replacement of the oxygen sensor...

The role of dispositional traits in accounting for country and ethnic group differences on adjustment.

PubMed

Matsumoto, David; Nakagawa, Sanae; Estrada, Aaron

2009-02-01

Country and ethnic group differences on adjustment have been demonstrated numerous times, and the source of these differences has been typically interpreted as cultural. We report two studies in which country (Study 1) and ethnic group (Study 2) differences on depression, anxiety, optimism versus pessimism, well-being, and self-esteem are mediated by dispositional traits. These findings provide an alternative explanation for previously reported country and ethnic group differences on these variables and encourage researchers to consider multiple sources, including traits, in their models and studies.

Incorporating the sampling design in weighting adjustments for panel attrition

PubMed Central

Chen, Qixuan; Gelman, Andrew; Tracy, Melissa; Norris, Fran H.; Galea, Sandro

2015-01-01

We review weighting adjustment methods for panel attrition and suggest approaches for incorporating design variables, such as strata, clusters and baseline sample weights. Design information can typically be included in attrition analysis using multilevel models or decision tree methods such as the CHAID algorithm. We use simulation to show that these weighting approaches can effectively reduce bias in the survey estimates that would occur from omitting the effect of design factors on attrition while keeping the resulted weights stable. We provide a step-by-step illustration on creating weighting adjustments for panel attrition in the Galveston Bay Recovery Study, a survey of residents in a community following a disaster, and provide suggestions to analysts in decision making about weighting approaches. PMID:26239405

On-demand Reporting of Risk-adjusted and Smoothed Rates for Quality Profiling in ACS NSQIP.

PubMed

Cohen, Mark E; Liu, Yaoming; Huffman, Kristopher M; Ko, Clifford Y; Hall, Bruce L

2016-12-01

Surgical quality improvement depends on hospitals having accurate and timely information about comparative performance. Profiling accuracy is improved by risk adjustment and shrinkage adjustment to stabilize estimates. These adjustments are included in ACS NSQIP reports, where hospital odds ratios (OR) are estimated using hierarchical models built on contemporaneous data. However, the timeliness of feedback remains an issue. We describe an alternative, nonhierarchical approach, which yields risk- and shrinkage-adjusted rates. In contrast to our "Traditional" NSQIP method, this approach uses preexisting equations, built on historical data, which permits hospitals to have near immediate access to profiling results. We compared our traditional method to this new "on-demand" approach with respect to outlier determinations, kappa statistics, and correlations between logged OR and standardized rates, for 12 models (4 surgical groups by 3 outcomes). When both methods used the same contemporaneous data, there were similar numbers of hospital outliers and correlations between logged OR and standardized rates were high. However, larger differences were observed when the effect of contemporaneous versus historical data was added to differences in statistical methodology. The on-demand, nonhierarchical approach provides results similar to the traditional hierarchical method and offers immediacy, an "over-time" perspective, application to a broader range of models and data subsets, and reporting of more easily understood rates. Although the nonhierarchical method results are now available "on-demand" in a web-based application, the hierarchical approach has advantages, which support its continued periodic publication as the gold standard for hospital profiling in the program.

Psychological health of military children: Longitudinal evaluation of a family-centered prevention program to enhance family resilience

PubMed Central

Lester, Patricia; Stein, Judith A.; Saltzman, William; Woodward, Kirsten; MacDermid, Shelley W.; Milburn, Norweeta; Mogil, Catherine; Beardslee, William

2014-01-01

Family-centered preventive interventions have been proposed as relevant to mitigating psychological health risk and promoting resilience in military families facing wartime deployment and reintegration. This study evaluates the impact of a family-centered prevention program, Families OverComing Under Stress Family Resilience Training (FOCUS), on the psychological adjustment of military children. Two primary goals include: 1) Understanding the relationships of distress among family members using a longitudinal path model to assess relations at the child and family level, and 2) Determining pathways of program impact on child adjustment. Multilevel data analysis using structural equation modeling was conducted with de-identified service delivery data from 280 families (505 children ages 3-17) in two follow-up assessments. Standardized measures included Service Member and Civilian parental distress (Brief Symptom Inventory, PTSD Checklist – Military), child adjustment (Strengths and Difficulties Questionnaire), and family functioning (McMaster Family Assessment Device). Distress was significantly related among the service member parent, civilian parent and children. FOCUS improved family functioning, which in turn significantly reduced child distress at follow-up. Salient components of improved family functioning in reducing child distress mirrored resilience processes targeted by FOCUS. These findings underscore the public health potential of family-centered prevention for military families, and suggest areas for future research. PMID:23929043

Accounting for time- and space-varying changes in the gravity field to improve the network adjustment of relative-gravity data

USGS Publications Warehouse

Kennedy, Jeffrey R.; Ferre, Ty P.A.

2015-01-01

The relative gravimeter is the primary terrestrial instrument for measuring spatially and temporally varying gravitational fields. The background noise of the instrument—that is, non-linear drift and random tares—typically requires some form of least-squares network adjustment to integrate data collected during a campaign that may take several days to weeks. Here, we present an approach to remove the change in the observed relative-gravity differences caused by hydrologic or other transient processes during a single campaign, so that the adjusted gravity values can be referenced to a single epoch. The conceptual approach is an example of coupled hydrogeophysical inversion, by which a hydrologic model is used to inform and constrain the geophysical forward model. The hydrologic model simulates the spatial variation of the rate of change of gravity as either a linear function of distance from an infiltration source, or using a 3-D numerical groundwater model. The linear function can be included in and solved for as part of the network adjustment. Alternatively, the groundwater model is used to predict the change of gravity at each station through time, from which the accumulated gravity change is calculated and removed from the data prior to the network adjustment. Data from a field experiment conducted at an artificial-recharge facility are used to verify our approach. Maximum gravity change due to hydrology (observed using a superconducting gravimeter) during the relative-gravity field campaigns was up to 2.6 μGal d−1, each campaign was between 4 and 6 d and one month elapsed between campaigns. The maximum absolute difference in the estimated gravity change between two campaigns, two months apart, using the standard network adjustment method and the new approach, was 5.5 μGal. The maximum gravity change between the same two campaigns was 148 μGal, and spatial variation in gravity change revealed zones of preferential infiltration and areas of relatively high groundwater storage. The accommodation for spatially varying gravity change would be most important for long-duration campaigns, campaigns with very rapid changes in gravity and (or) campaigns where especially precise observed relative-gravity differences are used in the network adjustment.

Roll paper pilot. [mathematical model for predicting pilot rating of aircraft in roll task

NASA Technical Reports Server (NTRS)

Naylor, F. R.; Dillow, J. D.; Hannen, R. A.

1973-01-01

A mathematical model for predicting the pilot rating of an aircraft in a roll task is described. The model includes: (1) the lateral-directional aircraft equations of motion; (2) a stochastic gust model; (3) a pilot model with two free parameters; and (4) a pilot rating expression that is a function of rms roll angle and the pilot lead time constant. The pilot gain and lead time constant are selected to minimize the pilot rating expression. The pilot parameters are then adjusted to provide a 20% stability margin and the adjusted pilot parameters are used to compute a roll paper pilot rating of the aircraft/gust configuration. The roll paper pilot rating was computed for 25 aircraft/gust configurations. A range of actual ratings from 2 to 9 were encountered and the roll paper pilot ratings agree quite well with the actual ratings. In addition there is good correlation between predicted and measured rms roll angle.

The occurrence of Simpson's paradox if site-level effect was ignored in the TREAT Asia HIV Observational Database.

PubMed

Jiamsakul, Awachana; Kerr, Stephen J; Chandrasekaran, Ezhilarasi; Huelgas, Aizobelle; Taecharoenkul, Sineenart; Teeraananchai, Sirinya; Wan, Gang; Ly, Penh Sun; Kiertiburanakul, Sasisopin; Law, Matthew

2016-08-01

In multisite human immunodeficiency virus (HIV) observational cohorts, clustering of observations often occurs within sites. Ignoring clustering may lead to "Simpson's paradox" (SP) where the trend observed in the aggregated data is reversed when the groups are separated. This study aimed to investigate the SP in an Asian HIV cohort and the effects of site-level adjustment through various Cox regression models. Survival time from combination antiretroviral therapy (cART) initiation was analyzed using four Cox models: (1) no site adjustment; (2) site as a fixed effect; (3) stratification through site; and (4) shared frailty on site. A total of 6,454 patients were included from 23 sites in Asia. SP was evident in the year of cART initiation variable. Model (1) shows the hazard ratio (HR) for years 2010-2014 was higher than the HR for 2006-2009, compared to 2003-2005 (HR = 0.68 vs. 0.61). Models (2)-(4) consistently implied greater improvement in survival for those who initiated in 2010-2014 than 2006-2009 contrasting findings from model (1). The effects of other significant covariates on survival were similar across four models. Ignoring site can lead to SP causing reversal of treatment effects. Greater emphasis should be made to include site in survival models when possible. Copyright © 2016 Elsevier Inc. All rights reserved.

The derivation and validation of a simple model for predicting in-hospital mortality of acutely admitted patients to internal medicine wards.

PubMed

Sakhnini, Ali; Saliba, Walid; Schwartz, Naama; Bisharat, Naiel

2017-06-01

Limited information is available about clinical predictors of in-hospital mortality in acute unselected medical admissions. Such information could assist medical decision-making.To develop a clinical model for predicting in-hospital mortality in unselected acute medical admissions and to test the impact of secondary conditions on hospital mortality.This is an analysis of the medical records of patients admitted to internal medicine wards at one university-affiliated hospital. Data obtained from the years 2013 to 2014 were used as a derivation dataset for creating a prediction model, while data from 2015 was used as a validation dataset to test the performance of the model. For each admission, a set of clinical and epidemiological variables was obtained. The main diagnosis at hospitalization was recorded, and all additional or secondary conditions that coexisted at hospital admission or that developed during hospital stay were considered secondary conditions.The derivation and validation datasets included 7268 and 7843 patients, respectively. The in-hospital mortality rate averaged 7.2%. The following variables entered the final model; age, body mass index, mean arterial pressure on admission, prior admission within 3 months, background morbidity of heart failure and active malignancy, and chronic use of statins and antiplatelet agents. The c-statistic (ROC-AUC) of the prediction model was 80.5% without adjustment for main or secondary conditions, 84.5%, with adjustment for the main diagnosis, and 89.5% with adjustment for the main diagnosis and secondary conditions. The accuracy of the predictive model reached 81% on the validation dataset.A prediction model based on clinical data with adjustment for secondary conditions exhibited a high degree of prediction accuracy. We provide a proof of concept that there is an added value for incorporating secondary conditions while predicting probabilities of in-hospital mortality. Further improvement of the model performance and validation in other cohorts are needed to aid hospitalists in predicting health outcomes.

The anchor-based minimal important change, based on receiver operating characteristic analysis or predictive modeling, may need to be adjusted for the proportion of improved patients.

PubMed

Terluin, Berend; Eekhout, Iris; Terwee, Caroline B

2017-03-01

Patients have their individual minimal important changes (iMICs) as their personal benchmarks to determine whether a perceived health-related quality of life (HRQOL) change constitutes a (minimally) important change for them. We denote the mean iMIC in a group of patients as the "genuine MIC" (gMIC). The aims of this paper are (1) to examine the relationship between the gMIC and the anchor-based minimal important change (MIC), determined by receiver operating characteristic analysis or by predictive modeling; (2) to examine the impact of the proportion of improved patients on these MICs; and (3) to explore the possibility to adjust the MIC for the influence of the proportion of improved patients. Multiple simulations of patient samples involved in anchor-based MIC studies with different characteristics of HRQOL (change) scores and distributions of iMICs. In addition, a real data set is analyzed for illustration. The receiver operating characteristic-based and predictive modeling MICs equal the gMIC when the proportion of improved patients equals 0.5. The MIC is estimated higher than the gMIC when the proportion improved is greater than 0.5, and the MIC is estimated lower than the gMIC when the proportion improved is less than 0.5. Using an equation including the predictive modeling MIC, the log-odds of improvement, the standard deviation of the HRQOL change score, and the correlation between the HRQOL change score and the anchor results in an adjusted MIC reflecting the gMIC irrespective of the proportion of improved patients. Adjusting the predictive modeling MIC for the proportion of improved patients assures that the adjusted MIC reflects the gMIC. We assumed normal distributions and global perceived change scores that were independent on the follow-up score. Additionally, floor and ceiling effects were not taken into account. Copyright © 2017 Elsevier Inc. All rights reserved.

Association of church-sponsored activity participation and prevalence of overweight and obesity in African American Protestants, National Survey of American Life, 2001-2003.

PubMed

Taylor, Jerome; Belay, Brook; Park, Sohyun; Onufrak, Stephen; Dietz, William

2013-01-01

This study examines the relationships between participation in the African American church and overweight/obesity (body mass index (BMI) > or = 25 kg/m2). This cross-sectional analysis was based on the National Survey of American Life 2001-2003 and included 2,689 African American Protestant (AAP) adults. Multivariate logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for overweight/obesity. Two practices were examined--frequency of participation in church activities (excluding services) and frequency of church service attendance. Each practice was analyzed in separate models. Each model included the following covariates: age, marital status, education, poverty, smoking, and region of country. We also adjusted models for sex. After adjustment, African American Protestant men (AAPM) who participated in church activities at least weekly were more likely to be overweight/obese (aOR=2.17; 95% CI = 1.25, 3.77) compared to AAPM who did not participate in church activities. There was no statistically significant association between overweight/obesity and participation in church activities for AAPW. There was no association between overweight/obesity and attendance of church services for AAP men and women combined. For AAPM, participation in church activities was significantly associated with overweight/obesity. Further studies are required to determine why this association occurs in AAPM but not AAPW. Studies looking at the wider application of the several successful health initiatives targeting the AAP community should also be considered.

Modeling wind adjustment factor and midflame wind speed for Rothermel's surface fire spread model

Treesearch

Patricia L. Andrews

2012-01-01

Rothermel's surface fire spread model was developed to use a value for the wind speed that affects surface fire, called midflame wind speed. Models have been developed to adjust 20-ft wind speed to midflame wind speed for sheltered and unsheltered surface fuel. In this report, Wind Adjustment Factor (WAF) model equations are given, and the BehavePlus fire modeling...

Transient Numerical Modeling of Catalytic Channels

NASA Technical Reports Server (NTRS)

Struk, Peter M.; Dietrich, Daniel L.; Miller, Fletcher J.; T'ien, James S.

2007-01-01

This paper presents a transient model of catalytic combustion suitable for isolated channels and monolith reactors. The model is a lumped two-phase (gas and solid) model where the gas phase is quasi-steady relative to the transient solid. Axial diffusion is neglected in the gas phase; lateral diffusion, however, is accounted for using transfer coefficients. The solid phase includes axial heat conduction and external heat loss due to convection and radiation. The combustion process utilizes detailed gas and surface reaction models. The gas-phase model becomes a system of stiff ordinary differential equations while the solid phase reduces, after discretization, into a system of stiff ordinary differential-algebraic equations. The time evolution of the system came from alternating integrations of the quasi-steady gas and transient solid. This work outlines the numerical model and presents some sensitivity studies on important parameters including internal transfer coefficients, catalytic surface site density, and external heat-loss (if applicable). The model is compared to two experiments using CO fuel: (1) steady-state conversion through an isothermal platinum (Pt) tube and (2) transient propagation of a catalytic reaction inside a small Pt tube. The model requires internal mass-transfer resistance to match the experiments at lower residence times. Under mass-transport limited conditions, the model reasonably predicted exit conversion using global mass-transfer coefficients. Near light-off, the model results did not match the experiment precisely even after adjustment of mass-transfer coefficients. Agreement improved for the first case after adjusting the surface kinetics such that the net rate of CO adsorption increased compared to O2. The CO / O2 surface mechanism came from a sub-set of reactions in a popular CH4 / O2 mechanism. For the second case, predictions improved for lean conditions with increased external heat loss or adjustment of the kinetics as in the first case. Finally, the results show that different initial surface-species distribution leads to different steady-states under certain conditions. These results demonstrate the utility of a lumped two-phase model of a transient catalytic combustor with detailed chemistry.

Method and system for dual resolution translation stage

DOEpatents

Halpin, John Michael

2014-04-22

A dual resolution translation stage includes a stage assembly operable to receive an optical element and a low resolution adjustment device mechanically coupled to the stage assembly. The dual resolution stage also includes an adjustable pivot block mechanically coupled to the stage assembly. The adjustable pivot block includes a pivot shaft. The dual resolution stage further includes a lever arm mechanically coupled to the adjustable pivot block. The lever arm is operable to pivot about the pivot shaft. The dual resolution stage additionally includes a high resolution adjustment device mechanically coupled to the lever arm and the stage assembly.

[Comparison of three stand-level biomass estimation methods].

PubMed

Dong, Li Hu; Li, Feng Ri

2016-12-01

At present, the forest biomass methods of regional scale attract most of attention of the researchers, and developing the stand-level biomass model is popular. Based on the forestry inventory data of larch plantation (Larix olgensis) in Jilin Province, we used non-linear seemly unrelated regression (NSUR) to estimate the parameters in two additive system of stand-level biomass equations, i.e., stand-level biomass equations including the stand variables and stand biomass equations including the biomass expansion factor (i.e., Model system 1 and Model system 2), listed the constant biomass expansion factor for larch plantation and compared the prediction accuracy of three stand-level biomass estimation methods. The results indicated that for two additive system of biomass equations, the adjusted coefficient of determination (R a 2 ) of the total and stem equations was more than 0.95, the root mean squared error (RMSE), the mean prediction error (MPE) and the mean absolute error (MAE) were smaller. The branch and foliage biomass equations were worse than total and stem biomass equations, and the adjusted coefficient of determination (R a 2 ) was less than 0.95. The prediction accuracy of a constant biomass expansion factor was relatively lower than the prediction accuracy of Model system 1 and Model system 2. Overall, although stand-level biomass equation including the biomass expansion factor belonged to the volume-derived biomass estimation method, and was different from the stand biomass equations including stand variables in essence, but the obtained prediction accuracy of the two methods was similar. The constant biomass expansion factor had the lower prediction accuracy, and was inappropriate. In addition, in order to make the model parameter estimation more effective, the established stand-level biomass equations should consider the additivity in a system of all tree component biomass and total biomass equations.

Clinical-Radiological Parameters Improve the Prediction of the Thrombolysis Time Window by Both MRI Signal Intensities and DWI-FLAIR Mismatch.

PubMed

Madai, Vince Istvan; Wood, Carla N; Galinovic, Ivana; Grittner, Ulrike; Piper, Sophie K; Revankar, Gajanan S; Martin, Steve Z; Zaro-Weber, Olivier; Moeller-Hartmann, Walter; von Samson-Himmelstjerna, Federico C; Heiss, Wolf-Dieter; Ebinger, Martin; Fiebach, Jochen B; Sobesky, Jan

2016-01-01

With regard to acute stroke, patients with unknown time from stroke onset are not eligible for thrombolysis. Quantitative diffusion weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR) MRI relative signal intensity (rSI) biomarkers have been introduced to predict eligibility for thrombolysis, but have shown heterogeneous results in the past. In the present work, we investigated whether the inclusion of easily obtainable clinical-radiological parameters would improve the prediction of the thrombolysis time window by rSIs and compared their performance to the visual DWI-FLAIR mismatch. In a retrospective study, patients from 2 centers with proven stroke with onset <12 h were included. The DWI lesion was segmented and overlaid on ADC and FLAIR images. rSI mean and SD, were calculated as follows: (mean ROI value/mean value of the unaffected hemisphere). Additionally, the visual DWI-FLAIR mismatch was evaluated. Prediction of the thrombolysis time window was evaluated by the area-under-the-curve (AUC) derived from receiver operating characteristic (ROC) curve analysis. Factors such as the association of age, National Institutes of Health Stroke Scale, MRI field strength, lesion size, vessel occlusion and Wahlund-Score with rSI were investigated and the models were adjusted and stratified accordingly. In 82 patients, the unadjusted rSI measures DWI-mean and -SD showed the highest AUCs (AUC 0.86-0.87). Adjustment for clinical-radiological covariates significantly improved the performance of FLAIR-mean (0.91) and DWI-SD (0.91). The best prediction results based on the AUC were found for the final stratified and adjusted models of DWI-SD (0.94) and FLAIR-mean (0.96) and a multivariable DWI-FLAIR model (0.95). The adjusted visual DWI-FLAIR mismatch did not perform in a significantly worse manner (0.89). ADC-rSIs showed fair performance in all models. Quantitative DWI and FLAIR MRI biomarkers as well as the visual DWI-FLAIR mismatch provide excellent prediction of eligibility for thrombolysis in acute stroke, when easily obtainable clinical-radiological parameters are included in the prediction models. © 2016 S. Karger AG, Basel.

Relations between aggression and adjustment in chinese children: moderating effects of academic achievement.

PubMed

Yang, Fan; Chen, Xinyin; Wang, Li

2014-01-01

The primary purpose of the study was to examine the moderating effects of academic achievement on relations between aggressive behavior and social and psychological adjustment in Chinese children. A sample of children (N = 1,171; 591 boys, 580 girls; initial M age = 9 years) in China participated in the study. Two waves of longitudinal data were collected in Grades 3 and 4 from multiple sources including peer nominations, teacher ratings, self-reports, and school records. The results indicated that the main effects of aggression on adjustment were more evident than those of adjustment on aggression. Moreover, aggression was negatively associated with later leadership status and positively associated with later peer victimization, mainly for high-achieving children. The results suggested that consistent with the resource-potentiating model, academic achievement served to enhance the positive development of children with low aggression. On the other hand, although the findings indicated fewer main effects of adjustment on aggression, loneliness, depression, and perceived social incompetence positively predicted later aggression for low-achieving, but not high-achieving, children, which suggested that consistent with the stress-buffering model, academic achievement protected children with psychological difficulties from developing aggressive behavior. The results indicate that academic achievement is involved in behavioral and socioemotional development in different manners in Chinese children. Researchers should consider an integrative approach based on children's behavioral, psychological, and academic functions in designing prevention and intervention programs.

Accounting for individual differences and timing of events: estimating the effect of treatment on criminal convictions in heroin users.

PubMed

Røislien, Jo; Clausen, Thomas; Gran, Jon Michael; Bukten, Anne

2014-05-17

The reduction of crime is an important outcome of opioid maintenance treatment (OMT). Criminal intensity and treatment regimes vary among OMT patients, but this is rarely adjusted for in statistical analyses, which tend to focus on cohort incidence rates and rate ratios. The purpose of this work was to estimate the relationship between treatment and criminal convictions among OMT patients, adjusting for individual covariate information and timing of events, fitting time-to-event regression models of increasing complexity. National criminal records were cross linked with treatment data on 3221 patients starting OMT in Norway 1997-2003. In addition to calculating cohort incidence rates, criminal convictions was modelled as a recurrent event dependent variable, and treatment a time-dependent covariate, in Cox proportional hazards, Aalen's additive hazards, and semi-parametric additive hazards regression models. Both fixed and dynamic covariates were included. During OMT, the number of days with criminal convictions for the cohort as a whole was 61% lower than when not in treatment. OMT was associated with reduced number of days with criminal convictions in all time-to-event regression models, but the hazard ratio (95% CI) was strongly attenuated when adjusting for covariates; from 0.40 (0.35, 0.45) in a univariate model to 0.79 (0.72, 0.87) in a fully adjusted model. The hazard was lower for females and decreasing with older age, while increasing with high numbers of criminal convictions prior to application to OMT (all p < 0.001). The strongest predictors were level of criminal activity prior to entering into OMT, and having a recent criminal conviction (both p < 0.001). The effect of several predictors was significantly time-varying with their effects diminishing over time. Analyzing complex observational data regarding to fixed factors only overlooks important temporal information, and naïve cohort level incidence rates might result in biased estimates of the effect of interventions. Applying time-to-event regression models, properly adjusting for individual covariate information and timing of various events, allows for more precise and reliable effect estimates, as well as painting a more nuanced picture that can aid health care professionals and policy makers.

An integrated epidemiological and neural net model of the warfarin effect in managed care patients.

PubMed

Jacobs, David M; Stefanovic, Filip; Wilton, Greg; Gomez-Caminero, Andres; Schentag, Jerome J

2017-01-01

Risk assessment tools are utilized to estimate the risk for stroke and need of anticoagulation therapy for patients with atrial fibrillation (AF). These risk stratification scores are limited by the information inputted into them and a reliance on time-independent variables. The objective of this study was to develop a time-dependent neural net model to identify AF populations at high risk of poor clinical outcomes and evaluate the discriminatory ability of the model in a managed care population. We performed a longitudinal, cohort study within a health-maintenance organization from 1997 to 2008. Participants were identified with incident AF irrespective of warfarin status and followed through their duration within the database. Three clinical outcome measures were evaluated including stroke, myocardial infarction, and hemorrhage. A neural net model was developed to identify patients at high risk of clinical events and defined to be an "enriched" patient. The model defines the enrichment based on the top 10 minimum mean square error output parameters that describe the three clinical outcomes. Cox proportional hazard models were utilized to evaluate the outcome measures. Among 285 patients, the mean age was 74±12 years with a mean follow-up of 4.3±2.6 years, and 154 (54%) were treated with warfarin. After propensity score adjustment, warfarin use was associated with a slightly increased risk of adverse outcomes (including stroke, myocardial infarction, and hemorrhage), though it did not attain statistical significance (adjusted hazard ratio [aHR] =1.22; 95% confidence interval [CI] 0.75-1.97; p =0.42). Within the neural net model, subjects at high risk of adverse outcomes were identified and labeled as "enriched." Following propensity score adjustment, enriched subjects were associated with an 81% higher risk of adverse outcomes as compared to nonenriched subjects (aHR=1.81; 95% CI, 1.15-2.88; p =0.01). Enrichment methodology improves the statistical discrimination of meaningful endpoints when used in a health records-based analysis.

Two Models of Caregiver Strain and Bereavement Adjustment: A Comparison of Husband and Daughter Caregivers of Breast Cancer Hospice Patients

ERIC Educational Resources Information Center

Bernard, Lori L.; Guarnaccia, Charles A.

2003-01-01

Purpose: Caregiver bereavement adjustment literature suggests opposite models of impact of role strain on bereavement adjustment after care-recipient death--a Complicated Grief Model and a Relief Model. This study tests these competing models for husband and adult-daughter caregivers of breast cancer hospice patients. Design and Methods: This…

Comprehensive Search for Alzheimer Disease Susceptibility Loci in the APOE Region

PubMed Central

Jun, Gyungah; Vardarajan, Badri N.; Buros, Jacqueline; Yu, Chang-En; Hawk, Michele V.; Dombroski, Beth A.; Crane, Paul K.; Larson, Eric B.; Mayeux, Richard; Haines, Jonathan L.; Lunetta, Kathryn L.; Pericak-Vance, Margaret A.; Schellenberg, Gerard D.; Farrer, Lindsay A.

2013-01-01

Objective To evaluate the association of risk and age at onset (AAO) of Alzheimer disease (AD) with single-nucleotide polymorphisms (SNPs) in the chromosome 19 region including apolipoprotein E (APOE) and a repeat-length polymorphism in TOMM40 (poly-T, rs10524523). Design Conditional logistic regression models and survival analysis. Setting Fifteen genome-wide association study data sets assembled by the Alzheimer's Disease Genetics Consortium. Participants Eleven thousand eight hundred forty AD cases and 10 931 cognitively normal elderly controls. Main Outcome Measures Association of AD risk and AAO with genotyped and imputed SNPs located in an 800-Mb region including APOE in the entire Alzheimer's Disease Genetics Consortium data set and with the TOMM40 poly-T marker genotyped in a subset of 1256 cases and 1605 controls. Results In models adjusting for APOE ε4, no SNPs in the entire region were significantly associated with AAO at P<.001. Rs10524523 was not significantly associated with AD or AAO in models adjusting for APOE genotype or within the subset of ε3/ε3 subjects. Conclusions APOE alleles ε2, ε3, and ε4 account for essentially all the inherited risk of AD associated with this region. Other variants including a poly-T track in TOMM40 are not independent risk or AAO loci. PMID:22869155

Celebrating Teachers.

ERIC Educational Resources Information Center

Upham, Dayle

This essay presents a list of 11 qualities that outstanding teachers possess, including: (1) flexibility (being able to change plans at a moment's notice and make adjustments accordingly); (2) enthusiasm and energy (showing a drive to excite students and model positive behavior); (3) empathy (acting understanding and compassionate of parents as…

A Revised Thermosphere for the Mars Global Reference Atmospheric Model (Mars-GRAM Version 3.4)

NASA Technical Reports Server (NTRS)

Justus, C. G.; Johnson, D. L.; James, B. F.

1996-01-01

This report describes the newly-revised model thermosphere for the Mars Global Reference Atmospheric Model (Mars-GRAM, Version 3.4). It also provides descriptions of other changes made to the program since publication of the programmer's guide for Mars-GRAM Version 3.34. The original Mars-GRAM model thermosphere was based on the global-mean model of Stewart. The revised thermosphere is based largely on parameterizations derived from output data from the three-dimensional Mars Thermospheric Global Circulation Model (MTGCM). The new thermospheric model includes revised dependence on the 10.7 cm solar flux for the global means of exospheric temperature, temperature of the base of the thermosphere, and scale height for the thermospheric temperature variations, as well as revised dependence on orbital position for global mean height of the base of the thermosphere. Other features of the new thermospheric model are: (1) realistic variations of temperature and density with latitude and time of day, (2) more realistic wind magnitudes, based on improved estimates of horizontal pressure gradients, and (3) allowance for user-input adjustments to the model values for mean exospheric temperature and for height and temperature at the base of the thermosphere. Other new features of Mars-GRAM 3.4 include: (1) allowance for user-input values of climatic adjustment factors for temperature profiles from the surface to 75 km, and (2) a revised method for computing the sub-solar longitude position in the 'ORBIT' subroutine.

Psychosocial Working Conditions and Cognitive Complaints among Swedish Employees

PubMed Central

Stenfors, Cecilia U. D.; Magnusson Hanson, Linda; Oxenstierna, Gabriel; Theorell, Töres; Nilsson, Lars-Göran

2013-01-01

Background Cognitive complaints involving problems with concentration, memory, decision-making and thinking are relatively common in the work force. The sensitivity of both subjective and objective cognitive functioning to common psychiatric conditions, stress levels and to cognitive load makes it plausible that psychosocial working conditions play a role in cognitive complaints. Thus, this study aimed to test the associations between psychosocial work factors and cognitive complaints in nationally representative samples of the Swedish work force. Cross-sectional (n = 9751) and prospective (n = 3644; two time points two years apart) sequential multiple regression analyses were run, adjusting for general confounders, depressive- and sleeping problems. Additional prospective analyses were run adjusting for baseline cognitive complaints. Cross-sectional results High quantitative demands, information and communication technology (ICT) demands, underqualification and conflicts were positively associated with cognitive complaints, while social support, good resources at work and overqualification were negatively associated with cognitive complaints in all models. Skill discretion and decision authority were weakly associated with cognitive complaints. Conflicts were more strongly associated with cognitive complaints in women than in men, after adjustment for general confounders. Prospective results Quantitative job demands, ICT demands and underqualification were positively associated with future cognitive complaints in all models, including when adjusted for baseline cognitive complaints. Decision authority was weakly positively associated with future cognitive complaints, only after adjustment for depressive- and sleeping problems respectively. Social support was negatively associated with future cognitive complaints after adjustment for general confounders and baseline cognitive complaints. Skill discretion and resources were negatively associated with future cognitive complaints after adjustment for general confounders. The associations between quantitative demands and future cognitive complaints were stronger in women. Discussion/Conclusions The findings indicate that psychosocial working conditions should be taken into account when considering cognitive complaints among employees. PMID:23560101

Emotional insecurity about the community: A dynamic, within-person mediator of child adjustment in contexts of political violence.

PubMed

Cummings, E Mark; Merrilees, Christine; Taylor, Laura K; Goeke-Morey, Marcie; Shirlow, Peter

2017-02-01

Over 1 billion children worldwide are exposed to political violence and armed conflict. The current conclusions are qualified by limited longitudinal research testing sophisticated process-oriented explanatory models for child adjustment outcomes. In this study, consistent with a developmental psychopathology perspective emphasizing the value of process-oriented longitudinal study of child adjustment in developmental and social-ecological contexts, we tested emotional insecurity about the community as a dynamic, within-person mediating process for relations between sectarian community violence and child adjustment. Specifically, this study explored children's emotional insecurity at a person-oriented level of analysis assessed over 5 consecutive years, with child gender examined as a moderator of indirect effects between sectarian community violence and child adjustment. In the context of a five-wave longitudinal research design, participants included 928 mother-child dyads in Belfast (453 boys, 475 girls) drawn from socially deprived, ethnically homogenous areas that had experienced political violence. Youth ranged in age from 10 to 20 years and were 13.24 (SD = 1.83) years old on average at the initial time point. Greater insecurity about the community measured over multiple time points mediated relations between sectarian community violence and youth's total adjustment problems. The pathway from sectarian community violence to emotional insecurity about the community was moderated by child gender, with relations to emotional insecurity about the community stronger for girls than for boys. The results suggest that ameliorating children's insecurity about community in contexts of political violence is an important goal toward improving adolescents' well-being and adjustment. These results are discussed in terms of their translational research implications, consistent with a developmental psychopathology model for the interface between basic and intervention research.

Instrumental variables as bias amplifiers with general outcome and confounding.

PubMed

Ding, P; VanderWeele, T J; Robins, J M

2017-06-01

Drawing causal inference with observational studies is the central pillar of many disciplines. One sufficient condition for identifying the causal effect is that the treatment-outcome relationship is unconfounded conditional on the observed covariates. It is often believed that the more covariates we condition on, the more plausible this unconfoundedness assumption is. This belief has had a huge impact on practical causal inference, suggesting that we should adjust for all pretreatment covariates. However, when there is unmeasured confounding between the treatment and outcome, estimators adjusting for some pretreatment covariate might have greater bias than estimators without adjusting for this covariate. This kind of covariate is called a bias amplifier, and includes instrumental variables that are independent of the confounder, and affect the outcome only through the treatment. Previously, theoretical results for this phenomenon have been established only for linear models. We fill in this gap in the literature by providing a general theory, showing that this phenomenon happens under a wide class of models satisfying certain monotonicity assumptions. We further show that when the treatment follows an additive or multiplicative model conditional on the instrumental variable and the confounder, these monotonicity assumptions can be interpreted as the signs of the arrows of the causal diagrams.

Individual radiation therapy patient whole-body phantoms for peripheral dose evaluations: method and specific software.

PubMed

Alziar, I; Bonniaud, G; Couanet, D; Ruaud, J B; Vicente, C; Giordana, G; Ben-Harrath, O; Diaz, J C; Grandjean, P; Kafrouni, H; Chavaudra, J; Lefkopoulos, D; de Vathaire, F; Diallo, I

2009-09-07

This study presents a method aimed at creating radiotherapy (RT) patient-adjustable whole-body phantoms to permit retrospective and prospective peripheral dose evaluations for enhanced patient radioprotection. Our strategy involves virtual whole-body patient models (WBPM) in different RT treatment positions for both genders and for different age groups. It includes a software tool designed to match the anatomy of the phantoms with the anatomy of the actual patients, based on the quality of patient data available. The procedure for adjusting a WBPM to patient morphology includes typical dimensions available in basic auxological tables for the French population. Adjustment is semi-automatic. Because of the complexity of the human anatomy, skilled personnel are required to validate changes made in the phantom anatomy. This research is part of a global project aimed at proposing appropriate methods and software tools capable of reconstituting the anatomy and dose evaluations in the entire body of RT patients in an adapted treatment planning system (TPS). The graphic user interface is that of a TPS adapted to obtain a comfortable working process. Such WBPM have been used to supplement patient therapy planning images, usually restricted to regions involved in treatment. Here we report, as an example, the case of a patient treated for prostate cancer whose therapy planning images were complemented by an anatomy model. Although present results are preliminary and our research is ongoing, they appear encouraging, since such patient-adjusted phantoms are crucial in the optimization of radiation protection of patients and for follow-up studies.

NOTE: Individual radiation therapy patient whole-body phantoms for peripheral dose evaluations: method and specific software

NASA Astrophysics Data System (ADS)

Alziar, I.; Bonniaud, G.; Couanet, D.; Ruaud, J. B.; Vicente, C.; Giordana, G.; Ben-Harrath, O.; Diaz, J. C.; Grandjean, P.; Kafrouni, H.; Chavaudra, J.; Lefkopoulos, D.; de Vathaire, F.; Diallo, I.

2009-09-01

This study presents a method aimed at creating radiotherapy (RT) patient-adjustable whole-body phantoms to permit retrospective and prospective peripheral dose evaluations for enhanced patient radioprotection. Our strategy involves virtual whole-body patient models (WBPM) in different RT treatment positions for both genders and for different age groups. It includes a software tool designed to match the anatomy of the phantoms with the anatomy of the actual patients, based on the quality of patient data available. The procedure for adjusting a WBPM to patient morphology includes typical dimensions available in basic auxological tables for the French population. Adjustment is semi-automatic. Because of the complexity of the human anatomy, skilled personnel are required to validate changes made in the phantom anatomy. This research is part of a global project aimed at proposing appropriate methods and software tools capable of reconstituting the anatomy and dose evaluations in the entire body of RT patients in an adapted treatment planning system (TPS). The graphic user interface is that of a TPS adapted to obtain a comfortable working process. Such WBPM have been used to supplement patient therapy planning images, usually restricted to regions involved in treatment. Here we report, as an example, the case of a patient treated for prostate cancer whose therapy planning images were complemented by an anatomy model. Although present results are preliminary and our research is ongoing, they appear encouraging, since such patient-adjusted phantoms are crucial in the optimization of radiation protection of patients and for follow-up studies.

An evaluation of bias in propensity score-adjusted non-linear regression models.

PubMed

Wan, Fei; Mitra, Nandita

2018-03-01

Propensity score methods are commonly used to adjust for observed confounding when estimating the conditional treatment effect in observational studies. One popular method, covariate adjustment of the propensity score in a regression model, has been empirically shown to be biased in non-linear models. However, no compelling underlying theoretical reason has been presented. We propose a new framework to investigate bias and consistency of propensity score-adjusted treatment effects in non-linear models that uses a simple geometric approach to forge a link between the consistency of the propensity score estimator and the collapsibility of non-linear models. Under this framework, we demonstrate that adjustment of the propensity score in an outcome model results in the decomposition of observed covariates into the propensity score and a remainder term. Omission of this remainder term from a non-collapsible regression model leads to biased estimates of the conditional odds ratio and conditional hazard ratio, but not for the conditional rate ratio. We further show, via simulation studies, that the bias in these propensity score-adjusted estimators increases with larger treatment effect size, larger covariate effects, and increasing dissimilarity between the coefficients of the covariates in the treatment model versus the outcome model.

Support for solar energy collectors

DOEpatents

Cole, Corey; Ardell-Smith, Zachary; Ciasulli, John; Jensen, Soren

2016-11-01

A solar energy collection system can include support devices configured to accommodate misalignment of components during assembly. For example, the system can include piles fixed to the earth and an adjustable bearing assembly at the upper end of the pile. The adjustable bearing assembly can include at least one of a vertical adjustment device, a lateral adjustment device and an angular adjustment device. The solar energy collection system can also include a plurality of solar energy collection device pre-wired together and mounted to a support member so as to form modular units. The system can also include enhanced supports for wire trays extending between rows of solar energy collection devices.

Random-anisotropy model: Monotonic dependence of the coercive field on D/J

NASA Astrophysics Data System (ADS)

Saslow, W. M.; Koon, N. C.

1994-02-01

We present the results of a numerical study of the zero-temperature remanence and coercivity for the random anisotropy model (RAM), showing that, contrary to early calculations for this model, the coercive field increases monotonically with increases in the strength D of the random anisotropy relative to the strength J at the exchange field. Local-field adjustments with and without spin flips are considered. Convergence is difficult to obtain for small values of the anisotropy, suggesting that this is the likely source of the nonmonotonic behavior found in earlier studies. For both large and small anisotropy, each spin undergoes about one flip per hysteresis cycle, and about half of the spin flips occur in the vicinity of the coercive field. When only non-spin-flip adjustments are considered, at large anisotropy the coercivity is proportional to the anisotropy. At small anisotropy, the rate of convergence is comparable to that when spin flips are included.

Herd-of-origin effect on the post-weaning performance of centrally tested Nellore beef cattle.

PubMed

de Rezende Neves, Haroldo Henrique; Polin dos Reis, Felipe; Motta Paterno, Flávia; Rocha Guarini, Aline; Carvalheiro, Roberto; da Silva, Lilian Regina; de Oliveira, João Ademir; Aidar de Queiroz, Sandra

2014-10-01

The objective of a performance test station is to evaluate the performance of potential breeding bulls earlier in order to decrease the generation interval and increase genetic gain as well. This study evaluates the herd-of-origin influence on end-of-test weight (ETW), average daily weight gain during testing (ADG), average daily weight gain during the adjustment period (ADGadj), rib eye area (REA), marbling (MARB), subcutaneous fat thickness (SFT), conformation (C), early finishing (EF), muscling (M), navel (N) and temperament (T) scores, and scrotal circumference (SC) of Nellore cattle that underwent a performance test. We evaluated 664 animals that participated in the performance tests conducted at the Center for Performance CRV Lagoa between 2007 and 2012. Components of variance for each trait were estimated by an animal model (model 1), using the restricted maximum likelihood method. An alternative animal model (model 2) included, in addition to the fixed effects present in S1, the non-correlated random effect of herd-year (HY). A significant HY effect was observed on ETW, REA, SFT, ADGadj, C, and Cw (p < 0.05). The estimated heritability of all traits decreased when the HY effect was included in the model; also, the bull rank, in deciles, changed significantly for traits ETW, REA, SFT, and C. The adjustment period did not completely remove the environmental effect of herd of origin on ETW, REA, SFT, and C. It is recommended that the herd-of-origin effect should be included in the statistical models used to predict the breeding values of the participants of these performance tests.

Prevalence of disability among US- and foreign-born Arab Americans: results from the 2000 US Census.

PubMed

Dallo, Florence J; Al Snih, Soham; Ajrouch, Kristine J

2009-01-01

Although the prevalence of disability for various racial and ethnic groups has been documented, little attention has been paid to Arab Americans in the United States. We estimated the age- and sex-adjusted prevalence of disability among older Arab Americans and examined the association between nativity status and self-reported physical and self-care disability before and after controlling for covariates. We used data from the 5% Public Use Microdata Samples of the 2000 US Census. Our sample included 4,225 individuals 65 years of age and older who identified with an Arab ancestry. Of these, 2,280 were foreign-born and 1,945 were US-born. The age- and sex-adjusted prevalence of having a physical disability was 31.2% for foreign- and 23.4% for US-born older Arab Americans, and the age- and sex- adjusted prevalence of having a self-care disability was 13.5% for foreign- and 6.8% for US-born Arab Americans. Iraqis reported the highest estimates for both disabilities (physical, 36.2%; self-care, 19.8%) compared to other Arab ethnic groups. In the crude model, foreign-born Arab Americans were more likely (OR=1.32; 95% CI=1.28, 1.36) to report a physical disability compared to US-born Arab Americans. When adjusting for English language ability in the final model, the odds of having a physical disability for foreign-born Arab Americans was protective compared to US-born Arab Americans (OR=0.92; 95% CI=0.88, 0.96). In the crude model, foreign-born Arab Americans were 1.82 times (95% CI=1.74, 1.90) more likely to report a self-care disability compared to US-born Arab Americans. In the fully adjusted model, this association was slightly attenuated (OR=1.32; 95% CI=1.24, 1.41). These findings indicate English language ability is associated with variations in reporting a physical disability. Future studies should include better measures of acculturation. Arab Americans are heterogeneous and should be disaggregated both by subgroups and from the white category in order to reveal a more accurate health and disease status profile for these groups. These efforts will assist in tailoring more effective interventions in reducing or preventing disability among Arab Americans 65 years of age and older. Copyright 2008 S. Karger AG, Basel.

A systematic review of health economic models and utility estimation methods in schizophrenia.

PubMed

Németh, Bertalan; Fasseeh, Ahmad; Molnár, Anett; Bitter, István; Horváth, Margit; Kóczián, Kristóf; Götze, Árpád; Nagy, Balázs

2018-06-01

There is a growing need for economic evaluations describing the disease course, as well as the costs and clinical outcomes related to the treatment of schizophrenia. Areas covered: A systematic review on studies describing health economic models in schizophrenia and a targeted literature review on utility mapping algorithms in schizophrenia were carried out. Models found in the review were collated and assessed in detail according to their type and various other attributes. Fifty-nine studies were included in the review. Modeling techniques varied from simple decision trees to complex simulation models. The models used various clinical endpoints as value drivers, 47% of the models used quality-adjusted life years, and eight percent used disability-adjusted life years to measure benefits, while others applied various clinical outcomes. Most models considered patients switching between therapies, and therapeutic adherence, compliance or persistence. The targeted literature review identified four main approaches to map PANSS scores to utility values. Expert commentary: Health economic models developed for schizophrenia showed great variability, with simulation models becoming more frequently used in the last decade. Using PANSS scores as the basis of utility estimations is justifiable.

Age of first arrest varies by gambling status in a cohort of young adults

PubMed Central

Martins, Silvia S.; Lee, Grace P.; Santaella, Julian; Liu, Weiwei; Ialongo, Nicholas S.; Storr, Carla L.

2015-01-01

Background and objectives To describe the association between social and problem gambling and first criminal arrest by age 23 in a cohort of urban, mainly African-American youth. Methods: Data for this study was derived from several annual interviews being completed on a community sample of 617 participants during late adolescence until age 23. Information on gambling status, engagement in deviant behaviors, illegal drug use, and arrest history were collected through yearly interviews. Analysis was carried out using Nelson-Aalen cumulative hazard models and simple and adjusted Cox proportional hazards models. Results More problem gamblers had been arrested before age 23 than social gamblers and non-gamblers, i.e. 65% of problem gamblers were arrested before age 23, compared to 38% of social gamblers and 24% non-gamblers. Social gambling was only significantly associated with the hazard of first arrest by age 23 in the unadjusted model (HR: 1.6, p<.001), but not after adjustment for covariates (HR: 1.1, p=0.47). Problem gambling was significantly associated with the hazard of first arrest by age 23 years in the unadjusted (HR: 3.6,p<.001) and adjusted models (HR:1.6, p=0.05). Conclusions and Scientific Significance Problem gambling was significantly associated with earlier age of being arrested. Dilution effects after adjustment for several deviant behaviors and illegal drug use by age 17 suggest that youth exposed to certain common factors may result in engagement in multiple risky behaviors, including problem gambling. Studies are needed to investigate the developmental pathways that lead to these combined behaviors among youth. PMID:24628694

Executive functions and theory of mind as predictors of social adjustment in childhood traumatic brain injury.

PubMed

Robinson, Kristen E; Fountain-Zaragoza, Stephanie; Dennis, Maureen; Taylor, H Gerry; Bigler, Erin D; Rubin, Kenneth; Vannatta, Kathryn; Gerhardt, Cynthia A; Stancin, Terry; Yeates, Keith Owen

2014-11-15

This study examined whether executive function and theory of mind mediate the effects of pediatric traumatic brain injury (TBI) on social adjustment, relative to children with orthopedic injury (OI). Participants included 19 children with severe TBI, 41 children with complicated mild/moderate TBI, and 57 children with OI. They completed measures of executive function, as well as cognitive, affective, and conative theory of mind. Parents provided ratings of children's social adjustment. Children with severe TBI performed more poorly than children with OI on executive function and theory of mind tasks and were rated by parents as having more behavioral symptoms and worse communication and social skills. Executive function and theory of mind were positively correlated with social skills and communication skills, and negatively correlated with behavioral symptoms. In multiple mediator models, theory of mind and executive function were not significant direct predictors of any measure of social adjustment, but mediated the association between injury and adjustment for children with severe TBI. Theory of mind was a significant independent mediator when predicting social skills, but executive function was not. TBI in children, particularly severe injury, is associated with poor social adjustment. The impact of TBI on children's social adjustment is likely mediated by its effects on executive function and theory of mind.

Executive Functions and Theory of Mind as Predictors of Social Adjustment in Childhood Traumatic Brain Injury

PubMed Central

Fountain-Zaragoza, Stephanie; Dennis, Maureen; Taylor, H. Gerry; Bigler, Erin D.; Rubin, Kenneth; Vannatta, Kathryn; Gerhardt, Cynthia A.; Stancin, Terry; Yeates, Keith Owen

2014-01-01

Abstract This study examined whether executive function and theory of mind mediate the effects of pediatric traumatic brain injury (TBI) on social adjustment, relative to children with orthopedic injury (OI). Participants included 19 children with severe TBI, 41 children with complicated mild/moderate TBI, and 57 children with OI. They completed measures of executive function, as well as cognitive, affective, and conative theory of mind. Parents provided ratings of children's social adjustment. Children with severe TBI performed more poorly than children with OI on executive function and theory of mind tasks and were rated by parents as having more behavioral symptoms and worse communication and social skills. Executive function and theory of mind were positively correlated with social skills and communication skills, and negatively correlated with behavioral symptoms. In multiple mediator models, theory of mind and executive function were not significant direct predictors of any measure of social adjustment, but mediated the association between injury and adjustment for children with severe TBI. Theory of mind was a significant independent mediator when predicting social skills, but executive function was not. TBI in children, particularly severe injury, is associated with poor social adjustment. The impact of TBI on children's social adjustment is likely mediated by its effects on executive function and theory of mind. PMID:25003478

Mathematical models and photogrammetric exploitation of image sensing

NASA Astrophysics Data System (ADS)

Puatanachokchai, Chokchai

Mathematical models of image sensing are generally categorized into physical/geometrical sensor models and replacement sensor models. While the former is determined from image sensing geometry, the latter is based on knowledge of the physical/geometric sensor models and on using such models for its implementation. The main thrust of this research is in replacement sensor models which have three important characteristics: (1) Highly accurate ground-to-image functions; (2) Rigorous error propagation that is essentially of the same accuracy as the physical model; and, (3) Adjustability, or the ability to upgrade the replacement sensor model parameters when additional control information becomes available after the replacement sensor model has replaced the physical model. In this research, such replacement sensor models are considered as True Replacement Models or TRMs. TRMs provide a significant advantage of universality, particularly for image exploitation functions. There have been several writings about replacement sensor models, and except for the so called RSM (Replacement Sensor Model as a product described in the Manual of Photogrammetry), almost all of them pay very little or no attention to errors and their propagation. This is because, it is suspected, the few physical sensor parameters are usually replaced by many more parameters, thus presenting a potential error estimation difficulty. The third characteristic, adjustability, is perhaps the most demanding. It provides an equivalent flexibility to that of triangulation using the physical model. Primary contributions of this thesis include not only "the eigen-approach", a novel means of replacing the original sensor parameter covariance matrices at the time of estimating the TRM, but also the implementation of the hybrid approach that combines the eigen-approach with the added parameters approach used in the RSM. Using either the eigen-approach or the hybrid approach, rigorous error propagation can be performed during image exploitation. Further, adjustability can be performed when additional control information becomes available after the TRM has been implemented. The TRM is shown to apply to imagery from sensors having different geometries, including an aerial frame camera, a spaceborne linear array sensor, an airborne pushbroom sensor, and an airborne whiskbroom sensor. TRM results show essentially negligible differences as compared to those from rigorous physical sensor models, both for geopositioning from single and overlapping images. Simulated as well as real image data are used to address all three characteristics of the TRM.

Uric acid and endothelial function in elderly community-dwelling subjects.

PubMed

Ticinesi, Andrea; Lauretani, Fulvio; Ceda, Gian Paolo; Ruggiero, Carmelinda; Ferrucci, Luigi; Aloe, Rosalia; Larsson, Anders; Cederholm, Tommy; Lind, Lars; Meschi, Tiziana; Maggio, Marcello

2017-03-01

The role of serum uric acid (SUA), an inflammatory agent and potential mediator of cardiovascular diseases, in endothelial function (EF) has been tested only in middle-aged subjects affected by specific diseases. Our aim was to assess the relationship between SUA and measures of EF in a cohort of elderly community-dwellers. This study involved 424 males and 426 females aged 70years from the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS), having complete data on SUA and EF assessed by flow-mediated vasodilation (FMD) and by intra-arterial infusion of acetylcholine (endothelium-dependent vasodilation, EDV) and sodium nitroprusside (endothelium-independent vasodilation, EIDV). Univariate and multivariate regression models obtained by backward selection from initial fully-adjusted models were built to assess the relationship between SUA and measures of EF in both genders. Cardiovascular risk factors, serum hormonal and metabolic mediators, and body composition were considered as potential confounders. In the univariate model, SUA was inversely associated in both genders with log(EDV) (β±SE males -0.39±0.17, p=0.03; females -0.57±0.19, p=0.003) and log(EIDV) (males -0.23±0.12, p=0.05; females -0.49±0.15, p=0.002), but not with log(FMD). After adjustment for BMI, only the association between SUA and log(EIDV) in females persisted, though attenuated (-0.32±0.16, p=0.049), and was no longer significant in the fully-adjusted multivariate model including waist/hip ratio. In conclusion, in older subjects, especially women, SUA is associated with EF not independently of a list of confounders including BMI and trunk fat mass, suggesting a role as surrogate metabolic marker rather than an active player in EF. Copyright © 2017 Elsevier Inc. All rights reserved.

Uric acid and endothelial function in elderly community-dwelling subjects

PubMed Central

Ticinesi, Andrea; Lauretani, Fulvio; Ceda, Gian Paolo; Ruggiero, Carmelinda; Ferrucci, Luigi; Aloe, Rosalia; Larsson, Anders; Cederholm, Tommy; Lind, Lars; Meschi, Tiziana; Maggio, Marcello

2017-01-01

The role of serum uric acid (SUA), an inflammatory agent and potential mediator of cardiovascular diseases, in endothelial function (EF) has been tested only in middle-aged subjects affected by specific diseases. Our aim was to assess the relationship between SUA and measures of EF in a cohort of elderly community-dwellers. This study involved 424 males and 426 females aged 70 years from the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS), having complete data on SUA and EF assessed by flow-mediated vasodilation (FMD) and by intra-arterial infusion of acetylcholine (endothelium-dependent vasodilation, EDV) and sodium nitroprusside (endothelium-independent vasodilation, EIDV). Univariate and multivariate regression models obtained by backward selection from initial fully-adjusted models were built to assess the relationship between SUA and measures of EF in both genders. Cardiovascular risk factors, serum hormonal and metabolic mediators, and body composition were considered as potential confounders. In the univariate model, SUA was inversely associated in both genders with log(EDV) (β ± SE males −0.39 ± 0.17, p = 0.03; females −0.57 ± 0.19, p = 0.003) and log(EIDV) (males −0.23 ± 0.12, p = 0.05; females −0.49 ± 0.15, p = 0.002), but not with log(FMD). After adjustment for BMI, only the association between SUA and log(EIDV) in females persisted, though attenuated (−0.32 ± 0.16, p = 0.049), and was no longer significant in the fully-adjusted multivariate model including waist/hip ratio. In conclusion, in older subjects, especially women, SUA is associated with EF not independently of a list of confounders including BMI and trunk fat mass, suggesting a role as surrogate metabolic marker rather than an active player in EF. PMID:28057563

Simultaneous Prediction of New Morbidity, Mortality, and Survival Without New Morbidity From Pediatric Intensive Care: A New Paradigm for Outcomes Assessment.

PubMed

Pollack, Murray M; Holubkov, Richard; Funai, Tomohiko; Berger, John T; Clark, Amy E; Meert, Kathleen; Berg, Robert A; Carcillo, Joseph; Wessel, David L; Moler, Frank; Dalton, Heidi; Newth, Christopher J L; Shanley, Thomas; Harrison, Rick E; Doctor, Allan; Jenkins, Tammara L; Tamburro, Robert; Dean, J Michael

2015-08-01

Assessments of care including quality assessments adjusted for physiological status should include the development of new morbidities as well as mortalities. We hypothesized that morbidity, like mortality, is associated with physiological dysfunction and could be predicted simultaneously with mortality. Prospective cohort study from December 4, 2011, to April 7, 2013. General and cardiac/cardiovascular PICUs at seven sites. Randomly selected PICU patients from their first PICU admission. None. Among 10,078 admissions, the unadjusted morbidity rates (measured with the Functional Status Scale and defined as an increase of ≥ 3 from preillness to hospital discharge) were 4.6% (site range, 2.6-7.7%) and unadjusted mortality rates were 2.7% (site range, 1.3-5.0%). Morbidity and mortality were significantly (p < 0.001) associated with physiological instability (measured with the Pediatric Risk of Mortality III score) in dichotomous (survival and death) and trichotomous (survival without new morbidity, survival with new morbidity, and death) models without covariate adjustments. Morbidity risk increased with increasing Pediatric Risk of Mortality III scores and then decreased at the highest Pediatric Risk of Mortality III values as potential morbidities became mortalities. The trichotomous model with covariate adjustments included age, admission source, diagnostic factors, baseline Functional Status Scale, and the Pediatric Risk of Mortality III score. The three-level goodness-of-fit test indicated satisfactory performance for the derivation and validation sets (p > 0.20). Predictive ability assessed with the volume under the surface was 0.50 ± 0.019 (derivation) and 0.50 ± 0.034 (validation) (vs chance performance = 0.17). Site-level standardized morbidity ratios were more variable than standardized mortality ratios. New morbidities were associated with physiological status and can be modeled simultaneously with mortality. Trichotomous outcome models including both morbidity and mortality based on physiological status are suitable for research studies and quality and other outcome assessments. This approach may be applicable to other assessments presently based only on mortality.

Investigating the prostate specific antigen, body mass index and age relationship: is an age-BMI-adjusted PSA model clinically useful?

PubMed

Harrison, Sean; Tilling, Kate; Turner, Emma L; Lane, J Athene; Simpkin, Andrew; Davis, Michael; Donovan, Jenny; Hamdy, Freddie C; Neal, David E; Martin, Richard M

2016-12-01

Previous studies indicate a possible inverse relationship between prostate-specific antigen (PSA) and body mass index (BMI), and a positive relationship between PSA and age. We investigated the associations between age, BMI, PSA, and screen-detected prostate cancer to determine whether an age-BMI-adjusted PSA model would be clinically useful for detecting prostate cancer. Cross-sectional analysis nested within the UK ProtecT trial of treatments for localized cancer. Of 18,238 men aged 50-69 years, 9,457 men without screen-detected prostate cancer (controls) and 1,836 men with prostate cancer (cases) met inclusion criteria: no history of prostate cancer or diabetes; PSA < 10 ng/ml; BMI between 15 and 50 kg/m 2 . Multivariable linear regression models were used to investigate the relationship between log-PSA, age, and BMI in all men, controlling for prostate cancer status. In the 11,293 included men, the median PSA was 1.2 ng/ml (IQR: 0.7-2.6); mean age 61.7 years (SD 4.9); and mean BMI 26.8 kg/m 2 (SD 3.7). There were a 5.1% decrease in PSA per 5 kg/m 2 increase in BMI (95% CI 3.4-6.8) and a 13.6% increase in PSA per 5-year increase in age (95% CI 12.0-15.1). Interaction tests showed no evidence for different associations between age, BMI, and PSA in men above and below 3.0 ng/ml (all p for interaction >0.2). The age-BMI-adjusted PSA model performed as well as an age-adjusted model based on National Institute for Health and Care Excellence (NICE) guidelines at detecting prostate cancer. Age and BMI were associated with small changes in PSA. An age-BMI-adjusted PSA model is no more clinically useful for detecting prostate cancer than current NICE guidelines. Future studies looking at the effect of different variables on PSA, independent of their effect on prostate cancer, may improve the discrimination of PSA for prostate cancer.

Socioeconomic disadvantage across the life-course and oral health in older age: findings from a longitudinal study of older British men.

PubMed

Ramsay, Sheena E; Papachristou, Efstathios; Watt, Richard G; Lennon, Lucy T; Papacosta, A Olia; Whincup, Peter H; Wannamethee, S Goya

2018-04-19

The influence of life-course socioeconomic disadvantage on oral health at older ages is not well-established. We examined the influence of socioeconomic factors in childhood, middle-age and older age on oral health at older ages, and tested conceptual life-course models (sensitive period, accumulation of risk, social mobility) to determine which best described observed associations. A representative cohort of British men aged 71-92 in 2010-12 included socioeconomic factors in childhood, middle-age and older age. Oral health assessment at 71-92 years (n = 1622) included tooth count, periodontal disease and self-rated oral health (excellent/good, fair/poor) (n = 2147). Life-course models (adjusted for age and town of residence) were compared with a saturated model using Likelihood-ratio tests. Socioeconomic disadvantage in childhood, middle-age and older age was associated with complete tooth loss at 71-92 years-age and town adjusted odds ratios (95% CI) were 1.39 (1.02-1.90), 2.26 (1.70-3.01), 1.83 (1.35-2.49), respectively. Socioeconomic disadvantage in childhood and middle-age was associated with poor self-rated oral health; adjusted odds ratios (95% CI) were 1.48 (1.19-1.85) and 1.45 (1.18-1.78), respectively. A sensitive period for socioeconomic disadvantage in middle-age provided the best model fit for tooth loss, while accumulation of risk model was the strongest for poor self-rated oral health. None of the life-course models were significant for periodontal disease measures. Socioeconomic disadvantage in middle-age has a particularly strong influence on tooth loss in older age. Poor self-rated oral health in older age is influenced by socioeconomic disadvantage across the life-course. Addressing socioeconomic factors in middle and older ages are likely to be important for better oral health in later life.

Heart failure in women and men during acute coronary syndrome and long-term cardiovascular mortality (the ABC-3* Study on Heart Disease) (*Adria, Bassano, Conegliano, and Padova Hospitals).

PubMed

Berton, Giuseppe; Cordiano, Rocco; Cavuto, Fiorella; Bagato, Francesco; Pellegrinet, Marco; Cati, Arianna

2016-10-01

We investigated the gender-based differences in the association between heart failure (HF) during acute coronary syndrome (ACS) and post-discharge, long-term cardiovascular (CV) mortality. The present study included 557 patients enrolled in three intensive coronary care units and discharged alive. HF during ACS was evaluated by Killip class and left ventricular ejection fraction (LVEF). Interaction between gender and HF after 15years of follow up was studied using Cox models including a formal interaction term. Median age was 67 (interquartile range [IQR], 59-75) years, 29% were females, 37% had non-ST elevation myocardial infarction and 32% Killip class>1, and median LVEF was 53% (IQR 46-61). All but five patients were followed up to 15years, representing 5332 person-years. Of these, 40.2% died of CV-related causes. Crude CV mortality rate was higher among women (52.2%) than men (35.3%; P<0.0001). At a univariable level, a negative interaction between female gender and Killip class for CV mortality was found [hazard ratio (HR)=0.51 (0.34-0.77), P=0.002]. In five multivariable models after controlling for age, main CV risk factors, clinical features, post-discharge medical treatment, and mechanical coronary reperfusion, the interaction was significant across all models [HR=0.63 (0.42-0.95), P=0.02 in the fully adjusted model]. LVEF showed no significant hazard associated with female gender on univariable analysis [HR=1.4 (0.9-0.2.0), P=0.11] but did so in all adjusted models [HR=1.7 (1.2-2.5), P=0.005 in the fully adjusted model]. Gender is a consistent, independent effect modifier in the association between HF and long-term CV mortality after ACS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Adaptive Core Simulation Employing Discrete Inverse Theory - Part I: Theory

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

Abdel-Khalik, Hany S.; Turinsky, Paul J.

2005-07-15

Use of adaptive simulation is intended to improve the fidelity and robustness of important core attribute predictions such as core power distribution, thermal margins, and core reactivity. Adaptive simulation utilizes a selected set of past and current reactor measurements of reactor observables, i.e., in-core instrumentation readings, to adapt the simulation in a meaningful way. A meaningful adaption will result in high-fidelity and robust adapted core simulator models. To perform adaption, we propose an inverse theory approach in which the multitudes of input data to core simulators, i.e., reactor physics and thermal-hydraulic data, are to be adjusted to improve agreement withmore » measured observables while keeping core simulator models unadapted. At first glance, devising such adaption for typical core simulators with millions of input and observables data would spawn not only several prohibitive challenges but also numerous disparaging concerns. The challenges include the computational burdens of the sensitivity-type calculations required to construct Jacobian operators for the core simulator models. Also, the computational burdens of the uncertainty-type calculations required to estimate the uncertainty information of core simulator input data present a demanding challenge. The concerns however are mainly related to the reliability of the adjusted input data. The methodologies of adaptive simulation are well established in the literature of data adjustment. We adopt the same general framework for data adjustment; however, we refrain from solving the fundamental adjustment equations in a conventional manner. We demonstrate the use of our so-called Efficient Subspace Methods (ESMs) to overcome the computational and storage burdens associated with the core adaption problem. We illustrate the successful use of ESM-based adaptive techniques for a typical boiling water reactor core simulator adaption problem.« less

Improving the Process of Adjusting the Parameters of Finite Element Models of Healthy Human Intervertebral Discs by the Multi-Response Surface Method.

PubMed

Gómez, Fátima Somovilla; Lorza, Rubén Lostado; Bobadilla, Marina Corral; García, Rubén Escribano

2017-09-21

The kinematic behavior of models that are based on the finite element method (FEM) for modeling the human body depends greatly on an accurate estimate of the parameters that define such models. This task is complex, and any small difference between the actual biomaterial model and the simulation model based on FEM can be amplified enormously in the presence of nonlinearities. The current paper attempts to demonstrate how a combination of the FEM and the MRS methods with desirability functions can be used to obtain the material parameters that are most appropriate for use in defining the behavior of Finite Element (FE) models of the healthy human lumbar intervertebral disc (IVD). The FE model parameters were adjusted on the basis of experimental data from selected standard tests (compression, flexion, extension, shear, lateral bending, and torsion) and were developed as follows: First, three-dimensional parameterized FE models were generated on the basis of the mentioned standard tests. Then, 11 parameters were selected to define the proposed parameterized FE models. For each of the standard tests, regression models were generated using MRS to model the six stiffness and nine bulges of the healthy IVD models that were created by changing the parameters of the FE models. The optimal combination of the 11 parameters was based on three different adjustment criteria. The latter, in turn, were based on the combination of stiffness and bulges that were obtained from the standard test FE simulations. The first adjustment criteria considered stiffness and bulges to be equally important in the adjustment of FE model parameters. The second adjustment criteria considered stiffness as most important, whereas the third considered the bulges to be most important. The proposed adjustment methods were applied to a medium-sized human IVD that corresponded to the L3-L4 lumbar level with standard dimensions of width = 50 mm, depth = 35 mm, and height = 10 mm. Agreement between the kinematic behavior that was obtained with the optimized parameters and that obtained from the literature demonstrated that the proposed method is a powerful tool with which to adjust healthy IVD FE models when there are many parameters, stiffnesses, and bulges to which the models must adjust.

Improving the Process of Adjusting the Parameters of Finite Element Models of Healthy Human Intervertebral Discs by the Multi-Response Surface Method

PubMed Central

Somovilla Gómez, Fátima

2017-01-01

The kinematic behavior of models that are based on the finite element method (FEM) for modeling the human body depends greatly on an accurate estimate of the parameters that define such models. This task is complex, and any small difference between the actual biomaterial model and the simulation model based on FEM can be amplified enormously in the presence of nonlinearities. The current paper attempts to demonstrate how a combination of the FEM and the MRS methods with desirability functions can be used to obtain the material parameters that are most appropriate for use in defining the behavior of Finite Element (FE) models of the healthy human lumbar intervertebral disc (IVD). The FE model parameters were adjusted on the basis of experimental data from selected standard tests (compression, flexion, extension, shear, lateral bending, and torsion) and were developed as follows: First, three-dimensional parameterized FE models were generated on the basis of the mentioned standard tests. Then, 11 parameters were selected to define the proposed parameterized FE models. For each of the standard tests, regression models were generated using MRS to model the six stiffness and nine bulges of the healthy IVD models that were created by changing the parameters of the FE models. The optimal combination of the 11 parameters was based on three different adjustment criteria. The latter, in turn, were based on the combination of stiffness and bulges that were obtained from the standard test FE simulations. The first adjustment criteria considered stiffness and bulges to be equally important in the adjustment of FE model parameters. The second adjustment criteria considered stiffness as most important, whereas the third considered the bulges to be most important. The proposed adjustment methods were applied to a medium-sized human IVD that corresponded to the L3–L4 lumbar level with standard dimensions of width = 50 mm, depth = 35 mm, and height = 10 mm. Agreement between the kinematic behavior that was obtained with the optimized parameters and that obtained from the literature demonstrated that the proposed method is a powerful tool with which to adjust healthy IVD FE models when there are many parameters, stiffnesses, and bulges to which the models must adjust. PMID:28934161

Development of a diagnosis- and procedure-based risk model for 30-day outcome after pediatric cardiac surgery.

PubMed

Crowe, Sonya; Brown, Kate L; Pagel, Christina; Muthialu, Nagarajan; Cunningham, David; Gibbs, John; Bull, Catherine; Franklin, Rodney; Utley, Martin; Tsang, Victor T

2013-05-01

The study objective was to develop a risk model incorporating diagnostic information to adjust for case-mix severity during routine monitoring of outcomes for pediatric cardiac surgery. Data from the Central Cardiac Audit Database for all pediatric cardiac surgery procedures performed in the United Kingdom between 2000 and 2010 were included: 70% for model development and 30% for validation. Units of analysis were 30-day episodes after the first surgical procedure. We used logistic regression for 30-day mortality. Risk factors considered included procedural information based on Central Cardiac Audit Database "specific procedures," diagnostic information defined by 24 "primary" cardiac diagnoses and "univentricular" status, and other patient characteristics. Of the 27,140 30-day episodes in the development set, 25,613 were survivals, 834 were deaths, and 693 were of unknown status (mortality, 3.2%). The risk model includes procedure, cardiac diagnosis, univentricular status, age band (neonate, infant, child), continuous age, continuous weight, presence of non-Down syndrome comorbidity, bypass, and year of operation 2007 or later (because of decreasing mortality). A risk score was calculated for 95% of cases in the validation set (weight missing in 5%). The model discriminated well; the C-index for validation set was 0.77 (0.81 for post-2007 data). Removal of all but procedural information gave a reduced C-index of 0.72. The model performed well across the spectrum of predicted risk, but there was evidence of underestimation of mortality risk in neonates undergoing operation from 2007. The risk model performs well. Diagnostic information added useful discriminatory power. A future application is risk adjustment during routine monitoring of outcomes in the United Kingdom to assist quality assurance. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Determinants of Perceived Stress in Individuals with Obesity: Exploring the Relationship of Potentially Obesity-Related Factors and Perceived Stress.

PubMed

Junne, Florian; Ziser, Katrin; Giel, Katrin Elisabeth; Schag, Kathrin; Skoda, Eva; Mack, Isabelle; Niess, Andreas; Zipfel, Stephan; Teufel, Martin

2017-01-01

Associations of specific types of stress with increased food intake and subsequent weight gain have been demonstrated in animal models as well as in experimental and epidemiological studies on humans. This study explores the research question of to what extent potentially obesity-related factors determine perceived stress in individuals with obesity. N = 547 individuals with obesity participated in a cross-sectional study assessing perceived stress as the outcome variable and potential determinants of stress related to obesity. Based on the available evidence, a five factorial model of 'obesity-related obesogenic stressors' was hypothesized, including the dimensions, 'drive for thinness', 'impulse regulation', 'ineffectiveness', 'social insecurity', and 'body dissatisfaction'. The model was tested using multiple linear regression analyses. The five factorial model of 'potentially obesity-related stressors' resulted in a total variance explanation of adjusted R² = 0.616 for males and adjusted R² = 0.595 for females for perceived stress. The relative variance contribution of the five included factors differed substantially for the two sexes. The findings of this cross-sectional study support the hypothesized, potentially obesity-related factors: 'drive for thinness', 'impulse regulation', 'ineffectiveness', 'social insecurity', and 'body dissatisfaction' as relevant determinants of perceived stress in individuals with obesity. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

Radiative forcing and rapid adjustment of absorbing aerosols in the Pearl River Delta Region of China

NASA Astrophysics Data System (ADS)

Liu, Z.; Yim, S. H. L.; Lau, G.

2016-12-01

Part of organic carbon defined as brown carbon (BrC) has been found to absorb solar radiation, especially in near-ultraviolet and blue bands, but their radiation impact is far less understood than black carbon (BC). Rapid adjustment thought to occur within a few weeks, induced by aerosol radiative effect and thereby alter cloud cover or other climate components. These effects are particularly pronounced for absorbing aerosols. The data gathered is from an online coupled model, WRF-Chem. A two-simulation test is conducted from July 8 to July 15. The baseline simulation doesn't account for aerosol-radiation interactions, whereas the sensitivity run includes it. The differences between these two simulations represent total effects of the aerosol instantaneous radiative forcing and subsequent rapid adjustment. In Figure 1, without cloud effect (clear sky), at the top of atmosphere (TOA), the SW radiation changes are negative in the PRD region, representing an overall cooling effect of aerosols. However, in the atmosphere (ATM), aerosols heat the atmosphere by absorbing incoming solar radiation with an average of 2.4 W/m2 (Table 1). After including rapid adjustment (all sky), the radiation change pattern becomes significantly different, especially at TOA and surface (SFC). This may be caused by cloud cover change due to rapid adjustment. The magnitude of SW radiation changes for all sky at all levels is smaller than that for clear sky. This result suggests the rapid adjustment counteracts the instantaneous radiative forcing of aerosols. At TOA, the cooling effect of the aerosol is 74% lower for all sky compared with clear sky, highlighting an overall warming effect of rapid adjustment in the PRD region. Aerosol-induced changes (W/m2) TOA ATM SFC Clear Sky -9.2 2.4 -11.6 All Sky -2.4 1.9 -4.3 Table 1. Aerosol-induced averaged changes in shortwave radiation due to aerosol-radiation interactions in the Pearl River Delta. The test shows the rapid adjustment of aerosols offsets part of the aerosol instantaneous negative radiation forcing, especially at TOA and SFC. The only absorbing aerosol species included in the test is BC. If absorption effects of dust and BrC are considered, the contribution of instantaneous radiative forcing and rapid adjustment may change.

Population Pharmacokinetics of Topiramate in Japanese Pediatric and Adult Patients With Epilepsy Using Routinely Monitored Data.

PubMed

Takeuchi, Masato; Yano, Ikuko; Ito, Satoko; Sugimoto, Mitsuhiro; Yamamoto, Shota; Yonezawa, Atsushi; Ikeda, Akio; Matsubara, Kazuo

2017-04-01

Topiramate is a second-generation antiepileptic drug used as monotherapy and adjunctive therapy in adults and children with partial seizures. A population pharmacokinetic (PPK) analysis was performed to improve the topiramate dosage adjustment for individualized treatment. Patients whose steady-state serum concentration of topiramate was routinely monitored at Kyoto University Hospital from April 2012 to March 2013 were included in the model-building data. A nonlinear mixed effects modeling program was used to evaluate the influence of covariates on topiramate pharmacokinetics. The obtained PPK model was evaluated by internal model validations, including goodness-of-fit plots and prediction-corrected visual predictive checks, and was externally confirmed using the validation data from January 2015 to December 2015. A total of 177 steady-state serum concentrations from 93 patients were used for the model-building analysis. The patients' age ranged from 2 to 68 years, and body weight ranged from 8.6 to 105 kg. The median serum concentration of topiramate was 1.7 mcg/mL, and half of the patients received carbamazepine coadministration. Based on a one-compartment model with first order absorption and elimination, the apparent volume of distribution was 105 L/70 kg, and the apparent clearance was allometrically related to the body weight as 2.25 L·h·70 kg without carbamazepine or phenytoin. Combination treatment with carbamazepine or phenytoin increased the apparent clearance to 3.51 L·h·70 kg. Goodness-of-fit plots, prediction-corrected visual predictive check, and external validation using the validation data from 43 patients confirmed an appropriateness of the final model. Simulations based on the final model showed that dosage adjustments allometrically scaling to body weight can equalize the serum concentrations in children of various ages and adults. The PPK model, using the power scaling of body weight, effectively elucidated the topiramate serum concentration profile ranging from pediatric to adult patients. Dosage adjustments based on body weight and concomitant antiepileptic drug help obtain the dosage of topiramate necessary to reach an effective concentration in each individual.

Latent profiles of problem behavior within learning, peer, and teacher contexts: identifying subgroups of children at academic risk across the preschool year.

PubMed

Bulotsky-Shearer, Rebecca J; Bell, Elizabeth R; Domínguez, Ximena

2012-12-01

Employing a developmental and ecological model, the study identified initial levels and rates of change in academic skills for subgroups of preschool children exhibiting problem behavior within routine classroom situations. Six distinct latent profile types of emotional and behavioral adjustment were identified for a cohort of low-income children early in the preschool year (N=4417). Profile types provided a descriptive picture of patterns of classroom externalizing, internalizing, and situational adjustment problems common to subgroups of children early in the preschool year. The largest profile type included children who exhibited low problem behavior and were characterized as well-adjusted to the preschool classroom early in the year. The other profile types were characterized by distinct combinations of elevated internalizing, externalizing, and situational problem behavior. Multinomial logistic regression identified younger children and boys at increased risk for classification in problem types, relative to the well-adjusted type. Latent growth models indicated that children classified within the extremely socially and academically disengaged profile type, started and ended the year with the lowest academic skills, relative to all other types. Implications for future research, policy, and practice are discussed. Copyright © 2012 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Mental distress among shift workers in Norwegian offshore petroleum industry--relative influence of individual and psychosocial work factors.

PubMed

Ljoså, Cathrine Haugene; Tyssen, Reidar; Lau, Bjørn

2011-11-01

This study aimed to investigate the association between individual and psychosocial work factors and mental distress among offshore shift workers in the Norwegian petroleum industry. All 2406 employees of a large Norwegian oil and gas company, who worked offshore during a two-week period in August 2006, were invited to participate in the web-based survey. Completed questionnaires were received from 1336 employees (56% response rate). The outcome variable was mental distress, assessed with a shortened version of the Hopkins Symptom Checklist (HSCL-5). The following individual factors were adjusted for: age, gender, marital status, and shift work locus of control. Psychosocial work factors included: night work, demands, control and support, and shift work-home interference. The level of mental distress was higher among men than women. In the adjusted regression model, the following were associated with mental distress: (i) high scores on quantitative demands, (ii) low level of support, and (iii) high level of shift work-home interference. Psychosocial work factors explained 76% of the total explained variance (adjusted R (²)=0.21) in the final adjusted model. Psychosocial work factors, such as quantitative demands, support, and shift work-home interference were independently associated with mental distress. Shift schedules were only univariately associated with mental distress.

Transitioning to adolescence: how changes in child personality and overreactive parenting predict adolescent adjustment problems.

PubMed

van den Akker, Alithe L; Deković, Maja; Prinzie, Peter

2010-01-01

The present study examined how changes in child Big Five personality characteristics and overreactive parenting during the transition from childhood to adolescence predict adolescent adjustment problems. The sample included 290 children, aged 8-9 years. At three moments, with 2-year intervals, mothers, fathers, and a teacher reported on the child's personality, and mothers and fathers reported on their parenting behavior. At the third measurement moment, mothers, fathers, and children reported on the child's adjustment problems. Rank-order stability of the personality dimensions and overreactive parenting were high. Univariate latent growth models revealed mean-level decreases for extraversion, conscientiousness, and imagination. Mean levels of benevolence, emotional stability, and overreactive parenting were stable. Multivariate latent growth models revealed that decreases in extraversion and emotional stability predicted internalizing problems, whereas decreases in benevolence, conscientiousness, and emotional stability predicted externalizing problems. Increases in overreactive parenting predicted externalizing, but not internalizing problems. The associations were similar for boys and girls. The results indicate that changes in child personality and overreactive parenting during the transition to adolescence are associated with adolescent adjustment problems. Overall, child personality was more important than overreactive parenting, and children were more likely to "act out" than to "withdraw" in reaction to overreactive parenting.

But I like PE: factors associated with enjoyment of physical education class in middle school girls.

PubMed

Barr-Anderson, Daheia J; Neumark-Sztainer, Dianne; Schmitz, Kathryn H; Ward, Dianne S; Conway, Terry L; Pratt, Charlotte; Baggett, Chris D; Lytle, Leslie; Pate, Russell R

2008-03-01

The current study examined associations between physical education (PE) class enjoyment and sociodemographic, personal, and perceived school environment factors among early adolescent girls. Participants included 1,511 sixth-grade girls who completed baseline assessments for the Trial of Activity in Adolescent Girls, with 50% indicating they enjoyed PE class a lot. Variables positively associated with PE class enjoyment included physical activity level, perceived benefits of physical activity, self-efficacy for leisure time physical activity, and perceived school climate for girls' physical activity as influenced by teachers, while body mass index was inversely associated with PE class enjoyment. After adjusting for all variables in the model, PE class enjoyment was significantly greater in Blacks than in Whites. In model testing, with mutual adjustment for all variables, self-efficacy was the strongest correlate of PE class enjoyment, followed by perceived benefits, race/ethnicity, and teachers' support for girls' physical activity, as compared to boys, at school. The overall model explained 11% of the variance in PE class enjoyment. Findings suggest that efforts to enhance girls' self-efficacy and perceived benefits and to provide a supportive PE class environment that promotes gender equality can potentially increase PE class enjoyment among young girls.

Bayesian inversion of the global present-day GIA signal uncertainty from RSL data

NASA Astrophysics Data System (ADS)

Caron, Lambert; Ivins, Erik R.; Adhikari, Surendra; Larour, Eric

2017-04-01

Various geophysical signals measured in the process of studying the present-day climate change (such as changes in the Earth gravitational potential, ocean altimery or GPS data) include a secular Glacial Isostatic Adjustment contribution that has to be corrected for. Yet, one of the current major challenges that Glacial Isostatic Adjustment modelling is currently struggling with is to accurately determine the uncertainty of the predicted present-day GIA signal. This is especially true at the global scale, where coupling between ice history and mantle rheology greatly contributes to the non-uniqueness of the solutions. Here we propose to use more than 11000 paleo sea level records to constrain a set of GIA Bayesian inversions and thoroughly explore its parameters space. We include two linearly relaxing models to represent the mantle rheology and couple them with a scalable ice history model in order to better assess the non-uniqueness of the solutions. From the resulting estimates of the Probability Density Function, we then extract maps of uncertainty affecting the present-day vertical land motion and geoid due to GIA at the global scale, and their associated expectation of the signal.

Mainstreaming: Sharing Ideas, Strategies, Materials, Techniques.

ERIC Educational Resources Information Center

Hillside School, Cushing, OK.

The manual provides teaching approaches based on a model of least to highest modification of instruction, which may be used for a continuum of special education placements ranging from regular classroom through hospital settings. The first section on adaptive techniques (requiring the least modification) includes suggestions to adjust time for…

Romantic Relationships and Adjustment Problems in China: The Moderating Effect of Classroom Romantic Context

ERIC Educational Resources Information Center

Hou, Jinqin; Natsuaki, Misaki N.; Zhang, Jianxin; Guo, Fei; Huang, Zheng; Wang, Mianbo; Chen, Zhiyan

2013-01-01

Theoretical and empirical research has shown that adolescent romantic relationships are associated with a wide range of developmental outcomes, including adverse consequences. The present study used a hierarchical linear model to examine the moderating effect of classroom romantic context on the association between adolescent romantic…

Women's Work Conditions and Marital Adjustment in Two-Earner Couples: A Structural Model.

ERIC Educational Resources Information Center

Sears, Heather A.; Galambos, Nancy L.

1992-01-01

Evaluated structural model of women's work conditions, women's stress, and marital adjustment using path analysis. Findings from 86 2-earner couples with adolescents indicated support for spillover model in which women's work stress and global stress mediated link between their work conditions and their perceptions of marital adjustment.…

Genotype by environment interaction for growth due to altitude in United States Angus cattle.

PubMed

Williams, J L; Bertrand, J K; Misztal, I; Łukaszewicz, M

2012-07-01

The objectives of this study were to determine if sires perform consistently across altitude and to quantify the genetic relationship between growth and survival at differing altitudes. Data from the American Angus Association included weaning weight (WW) adjusted to 205 (n = 77,771) and yearling weight adjusted to 365 (n = 39,450) d of age from 77,771 purebred Angus cattle born in Colorado between 1972 and 2007. Postweaning gain (PWG) was calculated by subtracting adjusted WW from adjusted yearling weight. Altitude was assigned to each record based upon the zip code of each herd in the database. Records for WW and PWG were each split into 2 traits measured at low and high altitude, with the records from medium altitude removed from the data due to inconsistencies between growth performance and apparent culling rate. A binary trait, survival (SV), was defined to account for censored records at yearling for each altitude. It was assumed that, at high altitude, individuals missing a yearling weight either died or required relocation to a lower altitude predominantly due to brisket disease, a condition common at high altitude. Model 1 considered each WW and PWG measured at 2 altitudes as separate traits. Model 2 treated PWG and SV measured as separate traits due to altitude. Models included the effects of weaning contemporary group, age of dam, animal additive genetic effects, and residual. Maternal genetic and maternal permanent environmental effects were included for WW. Heritability estimates for WW in Model 1 were 0.28 and 0.26 and for PWG were 0.26 and 0.19 with greater values in low altitude. Genetic correlations between growth traits measured at different altitude were moderate in magnitude: 0.74 for WW and 0.76 for PWG and indicate possibility of reranking of sires across altitude. Maternal genetic correlation between WW at varying altitude of 0.75 also indicates these may be different traits. In Model 2, heritabilities were 0.14 and 0.27 for PWG and 0.36 and 0.47 for SV. Genetic correlation between PWG measured at low and high altitude was 0.68. Favorable genetic correlations were estimated between SV and PWG within and between altitudes, suggesting that calves with genetics for increased growth from weaning to yearling also have increased genetic potential for SV. Genetic evaluations of PWG in different altitudes should consider preselection of the data, by using a censoring trait, like survivability to yearling.

Job adjustment and absence from work in mid-pregnancy in the Norwegian Mother and Child Cohort Study (MoBa).

PubMed

Kristensen, P; Nordhagen, R; Wergeland, E; Bjerkedal, T

2008-08-01

Pregnant women at work have special needs, and sick leave is common. However, job adjustment in pregnancy is addressed in European legislation. Our main objective was to examine if job adjustment was associated with reduced absence. This study is based on the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. 28,611 employed women filled in questionnaires in weeks 17 and 30 in pregnancy. The risk of absence for more than 2 weeks was studied among those who were not absent in week 17 (n = 22,932), and the probability of return to work in week 30 among those who were absent in week 17 (n = 5679). Data were based on self-report. The influence of job adjustment (three categories: not needed, needed but not obtained, needed and obtained) was analysed in additive models in multivariable binomial regression. Associations with other job characteristics and work environment factors were also analysed. The risk of absence for more than 2 weeks was 0.308 and the probability of return to work was 0.137. Compared with women who needed but did not achieve job adjustment, obtained job adjustment was associated with a 0.107 decreased risk of absence (95% confidence interval 0.090 to 0.125) in a model including other job characteristics and work environment factors. Job adjustment was correspondingly associated with a 0.041 (0.023 to 0.059) increased probability of return to work. Absence was associated with adverse work environment, whereas the opposite pattern was found for return to work among those who started off being absent. Job adjustment was associated with reduced absence from work in pregnancy. Results should be interpreted cautiously because of low participation in MoBa and potential information bias from self-reported data.

What Financial Incentives Will Be Created by Medicare Bundled Payments for Total Hip Arthroplasty?

PubMed

Clement, R Carter; Kheir, Michael M; Soo, Adrianne E; Derman, Peter B; Levin, L Scott; Fleisher, Lee A

2016-09-01

Bundled payments are gaining popularity in arthroplasty as a tactic for encouraging providers and hospitals to work together to reduce costs. However, this payment model could potentially motivate providers to avoid unprofitable patients, limiting their access to care. Rigorous risk adjustment can prevent this adverse effect, but most current bundling models use limited, if any, risk-adjustment techniques. This study aims to identify and quantify the financial incentives that are likely to develop with total hip arthroplasty (THA) bundled payments that are not accompanied by comprehensive risk stratification. Financial data were collected for all Medicare-eligible patients (age 65+) undergoing primary unilateral THA at an academic center over a 2-year period (n = 553). Bundles were considered to include operative hospitalizations and unplanned readmissions. Multivariate regression was performed to assess the impact of clinical and demographic factors on the variable cost of THA episodes, including unplanned readmissions. (Variable costs reflect the financial incentives that will emerge under bundled payments). Increased costs were associated with advanced age (P < .001), elevated body mass index (BMI; P = .005), surgery performed for hip fracture (P < .001), higher American Society of Anaesthesiologists (ASA) Physical Classification System grades (P < .001), and MCCs (Medicare modifier for major complications; P < .001). Regression coefficients were $155/y, $107/BMI point, $2775 for fracture cases, $2137/ASA grade, and $4892 for major complications. No association was found between costs and gender or race. If generalizable, our results suggest that Centers for Medicare and Medicaid Services bundled payments encompassing acute inpatient care should be adjusted upward by the aforementioned amounts (regression coefficients above) for advanced age, increasing BMI, cases performed for fractures, elevated ASA grade, and major complications (as defined by Medicare MCC modifiers). Furthermore, these figures likely underestimate costs in many bundling models which incorporate larger proportions of postdischarge care. Failure to adjust for factors affecting costs may create barriers to care for specific patient populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative risk of cerebrovascular adverse events in community-dwelling older adults using risperidone, olanzapine and quetiapine: a multiple propensity score-adjusted retrospective cohort study.

PubMed

Chatterjee, Satabdi; Chen, Hua; Johnson, Michael L; Aparasu, Rajender R

2012-10-01

Atypical antipsychotic agents have been associated with cerebrovascular adverse events, particularly in elderly dementia patients. However, limited evidence exists regarding comparative cerebrovascular profiles of individual atypical agents, particularly in community settings. The objective of this study was to evaluate the risk of cerebrovascular events associated with use of risperidone, olanzapine and quetiapine in community-dwelling older adults in the US. A propensity score-adjusted retrospective cohort design involving the IMS LifeLink™ Health Plan Claims Database was used for the study. The study population included all older adults (aged ≥50 years) who initiated risperidone, olanzapine or quetiapine anytime during 1 July 2000 to 30 June 2008. Patients were followed until hospitalization or an emergency room visit for a cerebrovascular event, or the end of the study period, whichever occurred earlier. The Cox proportional hazard regression model with time-varying covariates was used to evaluate the risk of cerebrovascular events during the follow-up period, using olanzapine as the reference. The covariates adjusted for in the final model included multiple propensity scores and exposure to other medications that could be associated with the risk of cerebrovascular events. A total of 2,458 cerebrovascular events were identified in the study cohort: 1,081 (21.38%) for risperidone users, 816 (18.75%) for olanzapine users and 561 (21.05%) for quetiapine users. After adjusting for propensity scores and other covariates, the Cox proportional hazard model revealed that use of quetiapine [hazard ratio (HR) 0.88; 95% CI 0.78, 0.99] but not risperidone (HR 1.05; 95% CI 0.95, 1.16) was associated with a decrease in the risk of cerebrovascular adverse events compared with olanzapine. The study suggested that quetiapine use may be associated with a moderately lower risk of cerebrovascular events than olanzapine in older adults. Prescribers should closely monitor the patients treated with atypical agents for the incidence of cerebrovascular adverse events.

Statin use and the risk of Clostridium difficile infection: a systematic review with meta-analysis.

PubMed

Tariq, Raseen; Mukhija, Dhruvika; Gupta, Arjun; Singh, Siddharth; Pardi, Darrell S; Khanna, Sahil

2018-01-01

Statins have pleiotropic effects beyond cholesterol lowering by immune modulation. The association of statins with primary Clostridium difficile infection (CDI) is unclear as studies have reported conflicting findings. We performed a systematic review and meta-analysis to evaluate the association between statin use and CDI. We searched MEDLINE, Embase, and Web of Science from January 1978 to December 2016 for studies assessing the association between statin use and CDI. The Newcastle-Ottawa Scale was used to assess the methodologic quality of included studies. Weighted summary estimates were calculated using generalized inverse variance with random-effects model. Eight studies (6 case-control and 2 cohort) were included in the meta-analysis, which comprised 156,722 patients exposed to statins and 356,185 controls, with 34,849 total cases of CDI available in 7 studies. The rate of CDI in patients with statin use was 4.3%, compared with 7.8% in patients without statin use. An overall meta-analysis of 8 studies using the random-effects model demonstrated that statins may be associated with a decreased risk of CDI (maximally adjusted odds ratio [OR], 0.80; 95% CI, 0.66-0.97; P =0.02). There was significant heterogeneity among the studies, with an I 2 of 79%. No publication bias was seen. Meta-analysis of studies that adjusted for confounders revealed no protective effect of statins (adjusted OR, 0.84; 95% CI, 0.70-1.01; P =0.06, I 2 =75%). However, a meta-analysis of only full-text studies using the random-effects model demonstrated a decreased risk of CDI with the use of statins (OR 0.77; 95% CI, 0.61-0.99; P =0.04, I 2 =85%). Meta-analyses of existing studies suggest that patients prescribed a statin may be at decreased risk for CDI. The results must be interpreted with caution given the significant heterogeneity and lack of benefit on analysis of studies that adjusted for confounders.

Evaluation of Rapid Adjustments to Radiative Forcing for Five Climate Forcing Agents in the Precipitation Driver Response Model Intercomparison Project (PDRMIP)

NASA Astrophysics Data System (ADS)

Smith, C. J.; Forster, P.; Richardson, T.; Myhre, G.

2016-12-01

Effective radiative forcing (ERF), rather than "traditional" radiative forcing (RF), has become an increasingly popular metric in recent years, as it more closely links the difference in the earth's top-of-atmosphere (TOA) energy budget to equilibrium near-surface temperature rise. One method to diagnose ERF is to take the difference of TOA radiative fluxes from two climate model runs (a perturbation and a control) with prescribed sea-surface temperatures and sea-ice coverage. ERF can be thought of as the sum of a direct forcing, which is the pure radiative effect of a forcing agent, plus rapid adjustments, which are changes in climate state triggered by the forcing agent that themselves affect the TOA energy budget and are unrelated to surface temperature changes.In addition to the classic experiment of doubling of CO2 (2xCO2), we analyse rapid adjustments to a tripling of methane (3xCH4), a quintupling of sulphate aerosol (5xSul), a ten times increase in black carbon (10xBC) and a 2% increase in the solar constant (2%Sol). We use CMIP-style climate model diagnostics from six participating models of the Precipitation Driver Response Model Intercomparison Project (PDRMIP).Assuming approximately linear contributions to the TOA flux differences, the rapid adjustments from changes in atmospheric temperature, surface temperature, surface albedo and water vapour can be cleanly and simply separated from the direct forcing by radiative kernels. The rapid adjustments are in turn decomposed into stratospheric and tropospheric components. We introduce kernels based on the HadGEM2 climate model and find similar results to those based on other models. Cloud adjustments are evaluated as a residual of the TOA radiative fluxes between all-sky and clear-sky runs once direct forcing and rapid adjustments have been subtracted. The cloud adjustments are also calculated online within the HadGEM2 model using the ISCCP simulator. For aerosol forcing experiments, rapid adjustments vary substantially between models. Much of the contribution to this model spread is in the cloud adjustments. We also notice a spread in the model calculations of direct forcing for greenhouse gases, which suggest differences in the radiative transfer parameterisations used by each model.

Accounting for energy and protein reserve changes in predicting diet-allowable milk production in cattle.

PubMed

Tedeschi, L O; Seo, S; Fox, D G; Ruiz, R

2006-12-01

Current ration formulation systems used to formulate diets on farms and to evaluate experimental data estimate metabolizable energy (ME)-allowable and metabolizable protein (MP)-allowable milk production from the intake above animal requirements for maintenance, pregnancy, and growth. The changes in body reserves, measured via the body condition score (BCS), are not accounted for in predicting ME and MP balances. This paper presents 2 empirical models developed to adjust predicted diet-allowable milk production based on changes in BCS. Empirical reserves model 1 was based on the reserves model described by the 2001 National Research Council (NRC) Nutrient Requirements of Dairy Cattle, whereas empirical reserves model 2 was developed based on published data of body weight and composition changes in lactating dairy cows. A database containing 134 individually fed lactating dairy cows from 3 trials was used to evaluate these adjustments in milk prediction based on predicted first-limiting ME or MP by the 2001 Dairy NRC and Cornell Net Carbohydrate and Protein System models. The analysis of first-limiting ME or MP milk production without adjustments for BCS changes indicated that the predictions of both models were consistent (r(2) of the regression between observed and model-predicted values of 0.90 and 0.85), had mean biases different from zero (12.3 and 5.34%), and had moderate but different roots of mean square errors of prediction (5.42 and 4.77 kg/d) for the 2001 NRC model and the Cornell Net Carbohydrate and Protein System model, respectively. The adjustment of first-limiting ME- or MP-allowable milk to BCS changes improved the precision and accuracy of both models. We further investigated 2 methods of adjustment; the first method used only the first and last BCS values, whereas the second method used the mean of weekly BCS values to adjust ME- and MP-allowable milk production. The adjustment to BCS changes based on first and last BCS values was more accurate than the adjustment to BCS based on the mean of all BCS values, suggesting that adjusting milk production for mean weekly variations in BCS added more variability to model-predicted milk production. We concluded that both models adequately predicted the first-limiting ME- or MP-allowable milk after adjusting for changes in BCS.

SHBG, sex hormones, and inflammatory markers in older women.

PubMed

Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Corsi, Anna Maria; Giallauria, Francesco; Guralnik, Jack M; Zuliani, Giovanni; Cattabiani, Chiara; Parrino, Stefano; Ablondi, Fabrizio; Dall'aglio, Elisabetta; Ceresini, Graziano; Basaria, Shehzad; Ferrucci, Luigi

2011-04-01

In premenopausal and older women, high testosterone and estradiol (E2) and low SHBG levels are associated with insulin resistance and diabetes, conditions characterized by low-grade inflammation. The aim of the study was to examine the relationship between SHBG, total testosterone, total E2, and inflammatory markers in older women. We conducted a retrospective cross-sectional study of 433 women at least 65 yr old from the InCHIANTI Study, Italy, who were not on hormone replacement therapy or recently hospitalized and who had complete data on SHBG, testosterone, E2, C-reactive protein (CRP), IL-6, soluble IL-6 receptor (sIL-6r), and TNF-α. Relationships between sex hormones and inflammatory markers were examined by multivariate linear regression analyses adjusted for age, body mass index, smoking, insulin, physical activity, and chronic disease. In fully adjusted analyses, SHBG was negatively associated with CRP (P = 0.007), IL-6 (P = 0.008), and sIL-6r (P = 0.02). In addition, testosterone was positively associated with CRP (P = 0.006), IL-6 (P = 0.001), and TNF-α (P = 0.0002). The negative relationship between testosterone and sIL-6r in an age-adjusted model (P = 0.02) was no longer significant in a fully adjusted model (P = 0.12). E2 was positively associated with CRP (P = 0.002) but not with IL-6 in fully adjusted models. In a final model including E2, testosterone, and SHBG, and all the confounders previously considered, SHBG (0.23 ± 0.08; P = 0.006) and E2 (0.21 ± 0.08; P = 0.007), but not testosterone (P = 0.21), were still significantly associated with CRP. In late postmenopausal women not on hormone replacement therapy, SHBG and E2 are, respectively, negative and positive, independent and significant correlates of a proinflammatory state.

SHBG, Sex Hormones, and Inflammatory Markers in Older Women

PubMed Central

Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Corsi, Anna Maria; Giallauria, Francesco; Guralnik, Jack M.; Zuliani, Giovanni; Cattabiani, Chiara; Parrino, Stefano; Ablondi, Fabrizio; Dall'Aglio, Elisabetta; Ceresini, Graziano; Basaria, Shehzad; Ferrucci, Luigi

2011-01-01

Context: In premenopausal and older women, high testosterone and estradiol (E2) and low SHBG levels are associated with insulin resistance and diabetes, conditions characterized by low-grade inflammation. Objective: The aim of the study was to examine the relationship between SHBG, total testosterone, total E2, and inflammatory markers in older women. Design and Patients: We conducted a retrospective cross-sectional study of 433 women at least 65 yr old from the InCHIANTI Study, Italy, who were not on hormone replacement therapy or recently hospitalized and who had complete data on SHBG, testosterone, E2, C-reactive protein (CRP), IL-6, soluble IL-6 receptor (sIL-6r), and TNF-α. Relationships between sex hormones and inflammatory markers were examined by multivariate linear regression analyses adjusted for age, body mass index, smoking, insulin, physical activity, and chronic disease. Results: In fully adjusted analyses, SHBG was negatively associated with CRP (P = 0.007), IL-6 (P = 0.008), and sIL-6r (P = 0.02). In addition, testosterone was positively associated with CRP (P = 0.006), IL-6 (P = 0.001), and TNF-α (P = 0.0002). The negative relationship between testosterone and sIL-6r in an age-adjusted model (P = 0.02) was no longer significant in a fully adjusted model (P = 0.12). E2 was positively associated with CRP (P = 0.002) but not with IL-6 in fully adjusted models. In a final model including E2, testosterone, and SHBG, and all the confounders previously considered, SHBG (0.23 ± 0.08; P = 0.006) and E2 (0.21 ± 0.08; P = 0.007), but not testosterone (P = 0.21), were still significantly associated with CRP. Conclusion: In late postmenopausal women not on hormone replacement therapy, SHBG and E2 are, respectively, negative and positive, independent and significant correlates of a proinflammatory state. PMID:21239514

Delayed heart rate recovery after exercise as a risk factor of incident type 2 diabetes mellitus after adjusting for glycometabolic parameters in men.

PubMed

Yu, Tae Yang; Jee, Jae Hwan; Bae, Ji Cheol; Hong, Won-Jung; Jin, Sang-Man; Kim, Jae Hyeon; Lee, Moon-Kyu

2016-10-15

Some studies have reported that delayed heart rate recovery (HRR) after exercise is associated with incident type 2 diabetes mellitus (T2DM). This study aimed to investigate the longitudinal association of delayed HRR following a graded exercise treadmill test (GTX) with the development of T2DM including glucose-associated parameters as an adjusting factor in healthy Korean men. Analyses including fasting plasma glucose, HOMA-IR, HOMA-β, and HbA1c as confounding factors and known confounders were performed. HRR was calculated as peak heart rate minus heart rate after a 1-min rest (HRR 1). Cox proportional hazards model was used to quantify the independent association between HRR and incident T2DM. During 9082 person-years of follow-up between 2006 and 2012, there were 180 (10.1%) incident cases of T2DM. After adjustment for age, BMI, systolic BP, diastolic BP, smoking status, peak heart rate, peak oxygen uptake, TG, LDL-C, HDL-C, fasting plasma glucose, HOMA-IR, HOMA-β, and HbA1c, the hazard ratios (HRs) [95% confidence interval (CI)] of incident T2DM comparing the second and third tertiles to the first tertile of HRR 1 were 0.867 (0.609-1.235) and 0.624 (0.426-0.915), respectively (p for trend=0.017). As a continuous variable, in the fully-adjusted model, the HR (95% CI) of incident T2DM associated with each 1 beat increase in HRR 1 was 0.980 (0.960-1.000) (p=0.048). This study demonstrated that delayed HRR after exercise predicts incident T2DM in men, even after adjusting for fasting glucose, HOMA-IR, HOMA-β, and HbA1c. However, only HRR 1 had clinical significance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Factor weighting in DRASTIC modeling.

PubMed

Pacheco, F A L; Pires, L M G R; Santos, R M B; Sanches Fernandes, L F

2015-02-01

Evaluation of aquifer vulnerability comprehends the integration of very diverse data, including soil characteristics (texture), hydrologic settings (recharge), aquifer properties (hydraulic conductivity), environmental parameters (relief), and ground water quality (nitrate contamination). It is therefore a multi-geosphere problem to be handled by a multidisciplinary team. The DRASTIC model remains the most popular technique in use for aquifer vulnerability assessments. The algorithm calculates an intrinsic vulnerability index based on a weighted addition of seven factors. In many studies, the method is subject to adjustments, especially in the factor weights, to meet the particularities of the studied regions. However, adjustments made by different techniques may lead to markedly different vulnerabilities and hence to insecurity in the selection of an appropriate technique. This paper reports the comparison of 5 weighting techniques, an enterprise not attempted before. The studied area comprises 26 aquifer systems located in Portugal. The tested approaches include: the Delphi consensus (original DRASTIC, used as reference), Sensitivity Analysis, Spearman correlations, Logistic Regression and Correspondence Analysis (used as adjustment techniques). In all cases but Sensitivity Analysis, adjustment techniques have privileged the factors representing soil characteristics, hydrologic settings, aquifer properties and environmental parameters, by leveling their weights to ≈4.4, and have subordinated the factors describing the aquifer media by downgrading their weights to ≈1.5. Logistic Regression predicts the highest and Sensitivity Analysis the lowest vulnerabilities. Overall, the vulnerability indices may be separated by a maximum value of 51 points. This represents an uncertainty of 2.5 vulnerability classes, because they are 20 points wide. Given this ambiguity, the selection of a weighting technique to integrate a vulnerability index may require additional expertise to be set up satisfactorily. Following a general criterion that weights must be proportional to the range of the ratings, Correspondence Analysis may be recommended as the best adjustment technique. Copyright © 2014 Elsevier B.V. All rights reserved.

Fast food purchasing and access to fast food restaurants: a multilevel analysis of VicLANES.

PubMed

Thornton, Lukar E; Bentley, Rebecca J; Kavanagh, Anne M

2009-05-27

While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES) - a cross-sectional multilevel study conducted within metropolitan Melbourne, Australia in 2003. The VicLANES data used in this analysis included 2547 participants from 49 census collector districts in metropolitan Melbourne, Australia. The outcome of interest was the total frequency of fast food purchased for consumption at home within the previous month (never, monthly and weekly) from five major fast food chains (Red Rooster, McDonalds, Kentucky Fried Chicken, Hungry Jacks and Pizza Hut). Three measures of fast food access were created: density and variety, defined as the number of fast food restaurants and the number of different fast food chains within 3 kilometres of road network distance respectively, and proximity defined as the road network distance to the closest fast food restaurant.Multilevel multinomial models were used to estimate the associations between fast food restaurant access and purchasing with never purchased as the reference category. Models were adjusted for confounders including determinants of demand (attitudes and tastes that influence food purchasing decisions) as well as individual and area socio-economic characteristics. Purchasing fast food on a monthly basis was related to the variety of fast food restaurants (odds ratio 1.13; 95% confidence interval 1.02 - 1.25) after adjusting for individual and area characteristics. Density and proximity were not found to be significant predictors of fast food purchasing after adjustment for individual socio-economic predictors. Although we found an independent association between fast food purchasing and access to a wider variety of fast food restaurant, density and proximity were not significant predictors. The methods used in our study are an advance on previous analyses.

Usefulness of the admission electrocardiogram to predict long-term outcomes after non-ST-elevation acute coronary syndrome (from the FRISC II, ICTUS, and RITA-3 [FIR] Trials).

PubMed

Damman, Peter; Holmvang, Lene; Tijssen, Jan G P; Lagerqvist, Bo; Clayton, Tim C; Pocock, Stuart J; Windhausen, Fons; Hirsch, Alexander; Fox, Keith A A; Wallentin, Lars; de Winter, Robbert J

2012-01-01

The aim of this study was to evaluate the independent prognostic value of qualitative and quantitative admission electrocardiographic (ECG) analysis regarding long-term outcomes after non-ST-segment elevation acute coronary syndromes (NSTE-ACS). From the Fragmin and Fast Revascularization During Instability in Coronary Artery Disease (FRISC II), Invasive Versus Conservative Treatment in Unstable Coronary Syndromes (ICTUS), and Randomized Intervention Trial of Unstable Angina 3 (RITA-3) patient-pooled database, 5,420 patients with NSTE-ACS with qualitative ECG data, of whom 2,901 had quantitative data, were included in this analysis. The main outcome was 5-year cardiovascular death or myocardial infarction. Hazard ratios (HRs) were calculated with Cox regression models, and adjustments were made for established outcome predictors. The additional discriminative value was assessed with the category-less net reclassification improvement and integrated discrimination improvement indexes. In the 5,420 patients, the presence of ST-segment depression (≥1 mm; adjusted HR 1.43, 95% confidence interval [CI] 1.25 to 1.63) and left bundle branch block (adjusted HR 1.64, 95% CI 1.18 to 2.28) were independently associated with long-term cardiovascular death or myocardial infarction. Risk increases were short and long term. On quantitative ECG analysis, cumulative ST-segment depression (≥5 mm; adjusted HR 1.34, 95% CI 1.05 to 1.70), the presence of left bundle branch block (adjusted HR 2.15, 95% CI 1.36 to 3.40) or ≥6 leads with inverse T waves (adjusted HR 1.22, 95% CI 0.97 to 1.55) was independently associated with long-term outcomes. No interaction was observed with treatment strategy. No improvements in net reclassification improvement and integrated discrimination improvement were observed after the addition of quantitative characteristics to a model including qualitative characteristics. In conclusion, in the FRISC II, ICTUS, and RITA-3 NSTE-ACS patient-pooled data set, admission ECG characteristics provided long-term prognostic value for cardiovascular death or myocardial infarction. Quantitative ECG characteristics provided no incremental discrimination compared to qualitative data. Copyright © 2012 Elsevier Inc. All rights reserved.

Pregnancy in polymyositis or dermatomyositis: retrospective results from a tertiary centre in China.

PubMed

Zhong, Zhiqiang; Lin, Fuan; Yang, Jing; Zhang, Fengchun; Zeng, Xiaofeng; You, Xin

2017-08-01

To examine if patients with PM/DM are at higher risk of complicated pregnancies. In a retrospective cohort in a large tertiary centre in North China, the outcomes of 144 pregnancies were evaluated in 62 women with PM/DM. Generalized linear mixed effect models were fitted to assess the effect of pregnancy occurring after disease on pregnancy outcomes including preterm birth (PTB), abortion (spontaneous or induced) and normal delivery. Adjustment for confounding factors including parity, maternal age and pregnancy-disease interval were achieved with a multivariable model. For women who became pregnant after disease onset, there was significantly higher risk of either PTB or spontaneous abortion (adjusted odds ratio, OR = 9.36, 95% CI: 1.10, 79.88; P = 0.041). The odds increase was more prominent if PM/DM was also active during pregnancy (adjusted OR = 435.35, 95% CI: 5.32, 35628.18; P = 0.007). Disease flare upon conception was observed in 4 of 22 post-PM/DM pregnancies (P = 0.125), and responded well to steroids and IVIG but resulted in PTB or spontaneous abortion. PM/DM, especially those less well controlled, might contribute to an increased risk of complicated pregnancy. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Psychological health of military children: longitudinal evaluation of a family-centered prevention program to enhance family resilience.

PubMed

Lester, Patricia; Stein, Judith A; Saltzman, William; Woodward, Kirsten; MacDermid, Shelley W; Milburn, Norweeta; Mogil, Catherine; Beardslee, William

2013-08-01

Family-centered preventive interventions have been proposed as relevant to mitigating psychological health risk and promoting resilience in military families facing wartime deployment and reintegration. This study evaluates the impact of a family-centered prevention program, Families OverComing Under Stress Family Resilience Training (FOCUS), on the psychological adjustment of military children. Two primary goals include (1) understanding the relationships of distress among family members using a longitudinal path model to assess relations at the child and family level and (2) determining pathways of program impact on child adjustment. Multilevel data analysis using structural equation modeling was conducted with deidentified service delivery data from 280 families (505 children aged 3-17) in two follow-up assessments. Standardized measures included service member and civilian parental distress (Brief Symptom Inventory, PTSD Checklist-Military), child adjustment (Strengths and Difficulties Questionnaire), and family functioning (McMaster Family Assessment Device). Distress was significantly related among the service member parent, civilian parent, and children. FOCUS improved family functioning, which in turn significantly reduced child distress at follow-up. Salient components of improved family functioning in reducing child distress mirrored resilience processes targeted by FOCUS. These findings underscore the public health potential of family-centered prevention for military families and suggest areas for future research. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

The association between short interpregnancy interval and preterm birth in Louisiana: a comparison of methods.

PubMed

Howard, Elizabeth J; Harville, Emily; Kissinger, Patricia; Xiong, Xu

2013-07-01

There is growing interest in the application of propensity scores (PS) in epidemiologic studies, especially within the field of reproductive epidemiology. This retrospective cohort study assesses the impact of a short interpregnancy interval (IPI) on preterm birth and compares the results of the conventional logistic regression analysis with analyses utilizing a PS. The study included 96,378 singleton infants from Louisiana birth certificate data (1995-2007). Five regression models designed for methods comparison are presented. Ten percent (10.17 %) of all births were preterm; 26.83 % of births were from a short IPI. The PS-adjusted model produced a more conservative estimate of the exposure variable compared to the conventional logistic regression method (β-coefficient: 0.21 vs. 0.43), as well as a smaller standard error (0.024 vs. 0.028), odds ratio and 95 % confidence intervals [1.15 (1.09, 1.20) vs. 1.23 (1.17, 1.30)]. The inclusion of more covariate and interaction terms in the PS did not change the estimates of the exposure variable. This analysis indicates that PS-adjusted regression may be appropriate for validation of conventional methods in a large dataset with a fairly common outcome. PS's may be beneficial in producing more precise estimates, especially for models with many confounders and effect modifiers and where conventional adjustment with logistic regression is unsatisfactory. Short intervals between pregnancies are associated with preterm birth in this population, according to either technique. Birth spacing is an issue that women have some control over. Educational interventions, including birth control, should be applied during prenatal visits and following delivery.

Association Of Church-Sponsored Activity Participation And Prevalence Of Overweight And Obesity In African American Protestants, National Survey Of American Life, 2001–2003

PubMed Central

Taylor, Jerome; Belay, Brook; Park, Sohyun; Onufrak, Stephen; Dietz, William

2015-01-01

Objective This study examines the relationships between participation in the African American church and overweight/obesity (body mass index (BMI) ≥25 kg/m2). Design: This cross-sectional analysis was based on the National Survey of American Life 2001–2003 and included 2,689 African American Protestant (AAP) adults. Multivariate logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for overweight/obesity. Two practices were examined – frequency of participation in church activities (excluding services) and frequency of church service attendance. Each practice was analyzed in separate models. Each model included the following covariates: age, marital status, education, poverty, smoking, and region of country. We also adjusted models for sex. Results After adjustment, African American Protestant men (AAPM) who participated in church activities at least weekly were more likely to be overweight/obese (aOR=2.17; 95% CI=1.25, 3.77) compared to AAPM who did not participate in church activities. There was no statistically significant association between overweight/obesity and participation in church activities for AAPW. There was no association between overweight/obesity and attendance of church services for AAP men and women combined. Conclusions For AAPM, participation in church activities was significantly associated with overweight/obesity. Further studies are required to determine why this association occurs in AAPM but not AAPW. Studies looking at the wider application of the several successful health initiatives targeting the AAP community should also be considered. PMID:23914418

Psychotic experiences and disability: Findings from the Collaborative Psychiatric Epidemiology Surveys.

PubMed

Oh, Hans; Koyanagi, Ai; Kelleher, Ian; DeVylder, Jordan

2018-03-01

Psychotic experiences are associated with a number of poor clinical outcomes, including multimorbid psychopathology, suicidal behavior, and poor treatment response. We wished to investigate the relationship between psychotic experiences and disability, including the following domains: cognition, mobility, self-care, social interaction, role functioning, and days out of role. We used three nationally representative and racially/ethnically diverse samples of the general US adult population: the National Comorbidity Survey Replication (NCS-R), the National Latino and Asian American Survey (NLAAS), and the National Survey of American Life (NSAL). Multi-variable logistic regression analyses were used to assess the associations between lifetime psychotic experiences (visual and auditory hallucinatory experiences and delusional ideation; WHO Composite International Diagnostic Interview psychosis screen) and 30-day impairments in functioning across disability domains (using the WHO Disability Assessment Schedule II). In all three samples, models were adjusted for socio-demographics and co-occurring psychiatric disorders. In the NCS-R, models were also adjusted for chronic health conditions. Across all three studies, our adjusted models showed that people with disability had anywhere from about 1.5 to over 3 times the odds of reporting lifetime psychotic experiences, depending on the domain. This was true for each disability domain, except self-care in the NLAAS and in the NSAL. Psychotic experiences are markers of risk for disability across a wide range of domains. This may explain the elevated rates of service utilization among individuals who report psychotic experiences and supports the need to assess for and respond to psychotic experiences even in the absence of psychotic disorder. Copyright © 2017 Elsevier B.V. All rights reserved.

Why Summary Comorbidity Measures Such As the Charlson Comorbidity Index and Elixhauser Score Work.

PubMed

Austin, Steven R; Wong, Yu-Ning; Uzzo, Robert G; Beck, J Robert; Egleston, Brian L

2015-09-01

Comorbidity adjustment is an important component of health services research and clinical prognosis. When adjusting for comorbidities in statistical models, researchers can include comorbidities individually or through the use of summary measures such as the Charlson Comorbidity Index or Elixhauser score. We examined the conditions under which individual versus summary measures are most appropriate. We provide an analytic proof of the utility of comorbidity summary measures when used in place of individual comorbidities. We compared the use of the Charlson and Elixhauser scores versus individual comorbidities in prognostic models using a SEER-Medicare data example. We examined the ability of summary comorbidity measures to adjust for confounding using simulations. We devised a mathematical proof that found that the comorbidity summary measures are appropriate prognostic or adjustment mechanisms in survival analyses. Once one knows the comorbidity score, no other information about the comorbidity variables used to create the score is generally needed. Our data example and simulations largely confirmed this finding. Summary comorbidity measures, such as the Charlson Comorbidity Index and Elixhauser scores, are commonly used for clinical prognosis and comorbidity adjustment. We have provided a theoretical justification that validates the use of such scores under many conditions. Our simulations generally confirm the utility of the summary comorbidity measures as substitutes for use of the individual comorbidity variables in health services research. One caveat is that a summary measure may only be as good as the variables used to create it.

Healthcare access and mammography screening in Michigan: a multilevel cross-sectional study

PubMed Central

2012-01-01

Background Breast cancer screening rates have increased over time in the United States. However actual screening rates appear to be lower among black women compared with white women. Purpose To assess determinants of breast cancer screening among women in Michigan USA, focusing on individual and neighborhood socio-economic status and healthcare access. Methods Data from 1163 women ages 50-74 years who participated in the 2008 Michigan Special Cancer Behavioral Risk Factor Survey were analyzed. County-level SES and healthcare access were obtained from the Area Resource File. Multilevel logistic regression models were fit using SAS Proc Glimmix to account for clustering of individual observations by county. Separate models were fit for each of the two outcomes of interest; mammography screening and clinical breast examination. For each outcome, two sequential models were fit; a model including individual level covariates and a model including county level covariates. Results After adjusting for misclassification bias, overall cancer screening rates were lower than reported by survey respondents; black women had lower mammography screening rates but higher clinical breast examination rates than white women. However, after adjusting for other individual level variables, race was not a significant predictor of screening. Having health insurance or a usual healthcare provider were the most important predictors of cancer screening. Discussion Access to healthcare is important to ensuring appropriate cancer screening among women in Michigan. PMID:22436125

18 CFR 367.4115 - Account 411.5, Investment tax credit adjustments, other.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., Investment tax credit adjustments, other. 367.4115 Section 367.4115 Conservation of Power and Water Resources....4115 Account 411.5, Investment tax credit adjustments, other. This account must include the amount of those investment tax credit adjustments not properly included in other accounts. ...

Dynamic gauge adjustment of high-resolution X-band radar data for convective rain storms: Model-based evaluation against measured combined sewer overflow

NASA Astrophysics Data System (ADS)

Borup, Morten; Grum, Morten; Linde, Jens Jørgen; Mikkelsen, Peter Steen

2016-08-01

Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5-30 min of rain data recorded by multiple rain gauges and propagating the rainfall estimates through a hydraulic urban drainage model. The model is built entirely from physical data, without any calibration, to avoid bias towards any specific type of rainfall estimate. The performance is assessed by comparing measured and modelled water levels at a weir downstream of a highly impermeable, well defined, 64 ha urban catchment, for nine overflow generating rain events. The dynamically adjusted radar data perform best when the aggregation period is as small as 10-20 min, in which case it performs much better than static adjusted radar data and data from rain gauges situated 2-3 km away.

The Study of an Optimal Robust Design and Adjustable Ordering Strategies in the HSCM

PubMed Central

Liao, Hung-Chang; Chen, Yan-Kwang; Wang, Ya-huei

2015-01-01

The purpose of this study was to establish a hospital supply chain management (HSCM) model in which three kinds of drugs in the same class and with the same indications were used in creating an optimal robust design and adjustable ordering strategies to deal with a drug shortage. The main assumption was that although each doctor has his/her own prescription pattern, when there is a shortage of a particular drug, the doctor may choose a similar drug with the same indications as a replacement. Four steps were used to construct and analyze the HSCM model. The computation technology used included a simulation, a neural network (NN), and a genetic algorithm (GA). The mathematical methods of the simulation and the NN were used to construct a relationship between the factor levels and performance, while the GA was used to obtain the optimal combination of factor levels from the NN. A sensitivity analysis was also used to assess the change in the optimal factor levels. Adjustable ordering strategies were also developed to prevent drug shortages. PMID:26451162

Abdominal adiposity and hot flashes among midlife women.

PubMed

Thurston, Rebecca C; Sowers, MaryFran R; Sutton-Tyrrell, Kim; Everson-Rose, Susan A; Lewis, Tené T; Edmundowicz, Daniel; Matthews, Karen A

2008-01-01

Two competing hypotheses suggest how adiposity may affect menopausal hot flashes. The "thin hypothesis" asserts that aromatization of androgens to estrogens in body fat should be associated with decreased hot flashes. Conversely, thermoregulatory models argue that body fat should be associated with increased hot flashes. The study objective was to examine associations between abdominal adiposity and hot flashes, including the role of reproductive hormones in these associations. The Study of Women's Health Across the Nation Heart Study (2001-2003) is an ancillary study to the Study of Women's Health Across the Nation, a community-based cohort study. Participants were 461 women (35% African American, 65% white) ages 45 to 58 years with an intact uterus and at least one ovary. Measures included a computed tomography scan to assess abdominal adiposity; reported hot flashes over the previous 2 weeks; and a blood sample for measurement of follicle-stimulating hormone, estradiol, and sex hormone-binding globulin-adjusted estradiol (free estradiol index). Associations were evaluated within multivariable logistic and linear regression models. Every 1-SD increase in total (odds ratio [OR]=1.28; 95% CI: 1.06-1.55) and subcutaneous (OR=1.30; 95% CI: 1.07-1.58) abdominal adiposity was associated with increased odds of hot flashes in age- and site-adjusted models. Visceral adiposity was not associated with hot flashes. Associations were not reduced when models included reproductive hormone concentrations. Increased abdominal adiposity, particularly subcutaneous adiposity, is associated with increased odds of hot flashes, favoring thermoregulatory models of hot flashes. Body fat may not protect women from hot flashes as once thought.

Deformable three-dimensional model architecture for interactive augmented reality in minimally invasive surgery.

PubMed

Vemuri, Anant S; Wu, Jungle Chi-Hsiang; Liu, Kai-Che; Wu, Hurng-Sheng

2012-12-01

Surgical procedures have undergone considerable advancement during the last few decades. More recently, the availability of some imaging methods intraoperatively has added a new dimension to minimally invasive techniques. Augmented reality in surgery has been a topic of intense interest and research. Augmented reality involves usage of computer vision algorithms on video from endoscopic cameras or cameras mounted in the operating room to provide the surgeon additional information that he or she otherwise would have to recognize intuitively. One of the techniques combines a virtual preoperative model of the patient with the endoscope camera using natural or artificial landmarks to provide an augmented reality view in the operating room. The authors' approach is to provide this with the least number of changes to the operating room. Software architecture is presented to provide interactive adjustment in the registration of a three-dimensional (3D) model and endoscope video. Augmented reality including adrenalectomy, ureteropelvic junction obstruction, and retrocaval ureter and pancreas was used to perform 12 surgeries. The general feedback from the surgeons has been very positive not only in terms of deciding the positions for inserting points but also in knowing the least change in anatomy. The approach involves providing a deformable 3D model architecture and its application to the operating room. A 3D model with a deformable structure is needed to show the shape change of soft tissue during the surgery. The software architecture to provide interactive adjustment in registration of the 3D model and endoscope video with adjustability of every 3D model is presented.

Comparison of the performance of the CMS Hierarchical Condition Category (CMS-HCC) risk adjuster with the Charlson and Elixhauser comorbidity measures in predicting mortality.

PubMed

Li, Pengxiang; Kim, Michelle M; Doshi, Jalpa A

2010-08-20

The Centers for Medicare and Medicaid Services (CMS) has implemented the CMS-Hierarchical Condition Category (CMS-HCC) model to risk adjust Medicare capitation payments. This study intends to assess the performance of the CMS-HCC risk adjustment method and to compare it to the Charlson and Elixhauser comorbidity measures in predicting in-hospital and six-month mortality in Medicare beneficiaries. The study used the 2005-2006 Chronic Condition Data Warehouse (CCW) 5% Medicare files. The primary study sample included all community-dwelling fee-for-service Medicare beneficiaries with a hospital admission between January 1st, 2006 and June 30th, 2006. Additionally, four disease-specific samples consisting of subgroups of patients with principal diagnoses of congestive heart failure (CHF), stroke, diabetes mellitus (DM), and acute myocardial infarction (AMI) were also selected. Four analytic files were generated for each sample by extracting inpatient and/or outpatient claims for each patient. Logistic regressions were used to compare the methods. Model performance was assessed using the c-statistic, the Akaike's information criterion (AIC), the Bayesian information criterion (BIC) and their 95% confidence intervals estimated using bootstrapping. The CMS-HCC had statistically significant higher c-statistic and lower AIC and BIC values than the Charlson and Elixhauser methods in predicting in-hospital and six-month mortality across all samples in analytic files that included claims from the index hospitalization. Exclusion of claims for the index hospitalization generally led to drops in model performance across all methods with the highest drops for the CMS-HCC method. However, the CMS-HCC still performed as well or better than the other two methods. The CMS-HCC method demonstrated better performance relative to the Charlson and Elixhauser methods in predicting in-hospital and six-month mortality. The CMS-HCC model is preferred over the Charlson and Elixhauser methods if information about the patient's diagnoses prior to the index hospitalization is available and used to code the risk adjusters. However, caution should be exercised in studies evaluating inpatient processes of care and where data on pre-index admission diagnoses are unavailable.

Assessing model uncertainty using hexavalent chromium and ...

EPA Pesticide Factsheets

Introduction: The National Research Council recommended quantitative evaluation of uncertainty in effect estimates for risk assessment. This analysis considers uncertainty across model forms and model parameterizations with hexavalent chromium [Cr(VI)] and lung cancer mortality as an example. The objective of this analysis is to characterize model uncertainty by evaluating the variance in estimates across several epidemiologic analyses.Methods: This analysis compared 7 publications analyzing two different chromate production sites in Ohio and Maryland. The Ohio cohort consisted of 482 workers employed from 1940-72, while the Maryland site employed 2,357 workers from 1950-74. Cox and Poisson models were the only model forms considered by study authors to assess the effect of Cr(VI) on lung cancer mortality. All models adjusted for smoking and included a 5-year exposure lag, however other latency periods and model covariates such as age and race were considered. Published effect estimates were standardized to the same units and normalized by their variances to produce a standardized metric to compare variability in estimates across and within model forms. A total of 7 similarly parameterized analyses were considered across model forms, and 23 analyses with alternative parameterizations were considered within model form (14 Cox; 9 Poisson). Results: Across Cox and Poisson model forms, adjusted cumulative exposure coefficients for 7 similar analyses ranged from 2.47

Inclusion of Functional Status Measures in the Risk Adjustment of 30-Day Mortality After Transcatheter Aortic Valve Replacement: A Report From the Society of Thoracic Surgeons/American College of Cardiology TVT Registry.

PubMed

Arnold, Suzanne V; O'Brien, Sean M; Vemulapalli, Sreekanth; Cohen, David J; Stebbins, Amanda; Brennan, J Matthew; Shahian, David M; Grover, Fred L; Holmes, David R; Thourani, Vinod H; Peterson, Eric D; Edwards, Fred H

2018-03-26

The aim of this study was to develop and validate a risk adjustment model for 30-day mortality after transcatheter aortic valve replacement (TAVR) that accounted for both standard clinical factors and pre-procedural health status and frailty. Assessment of risk for TAVR is important both for patient selection and provider comparisons. Prior efforts for risk adjustment have focused on in-hospital mortality, which is easily obtainable but can be biased because of early discharge of ill patients. Using data from patients who underwent TAVR as part of the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry (June 2013 to May 2016), a hierarchical logistic regression model to estimate risk for 30-day mortality after TAVR based only on pre-procedural factors and access site was developed and internally validated. The model included factors from the original TVT Registry in-hospital mortality model but added the Kansas City Cardiomyopathy Questionnaire (health status) and gait speed (5-m walk test). Among 21,661 TAVR patients at 188 sites, 1,025 (4.7%) died within 30 days. Independent predictors of 30-day death included older age, low body weight, worse renal function, peripheral artery disease, home oxygen, prior myocardial infarction, left main coronary artery disease, tricuspid regurgitation, nonfemoral access, worse baseline health status, and inability to walk. The predicted 30-day mortality risk ranged from 1.1% (lowest decile of risk) to 13.8% (highest decile of risk). The model was able to stratify risk on the basis of patient factors with good discrimination (C = 0.71 [derivation], C = 0.70 [split-sample validation]) and excellent calibration, both overall and in key patient subgroups. A clinical risk model was developed for 30-day death after TAVR that included clinical data as well as health status and frailty. This model will facilitate tracking outcomes over time as TAVR expands to lower risk patients and to less experienced sites and will allow an objective comparison of short-term mortality rates across centers. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Depression and anger in fathers of unsettled infants: A community cohort study.

PubMed

Cook, Fallon; Giallo, Rebecca; Petrovic, Zvezdana; Coe, Amy; Seymour, Monique; Cann, Warren; Hiscock, Harriet

2017-02-01

To examine the relationship between unsettled infant behaviour and fathers' depressive symptoms, cognitions surrounding infant sleep (anger, doubt), and personal sleep, in a community cohort. Data were collected from 102 fathers of healthy infants at 4 weeks, 4 months and 6 months of age. Measures included father report of infant sleep and crying problems, depressive symptoms, cognitions about infant sleep and own sleep quality and quantity. Data were analysed using adjusted regression models. Sleep problems at 4 months of age were associated with increased depressive symptoms (adjusted mean difference 2.64 (1.27-4.00)), doubt (adjusted mean difference 1.82 (0.40-3.25)), anger (adjusted mean difference 1.86 (0.51-3.20)), poor personal sleep quantity (adjusted odds ratio (OR) 0.21; 95% confidence interval (CI) 0.09-0.51) and quality (adjusted OR 0.20; 95% CI 0.08-0.51); and at 6 months of age, with increased depressive symptoms (adjusted mean difference 2.56 (1.28-3.84)), anger (adjusted mean difference 1.63 (0.40-2.87)), poor personal sleep quantity (adjusted OR 0.14; 95% CI 0.05-0.38) and quality (adjusted OR 0.28; 95% CI 0.11-0.72). Infant cry problems at 4 months were associated with increased anger (adjusted mean difference 1.98 (0.60-3.36)) and doubt (adjusted mean difference 1.55 (0.05-3.05)); and at 6 months, with increased depressive symptoms (adjusted mean difference 3.04 (1.59-4.69)), anger (adjusted mean difference 2.73 (1.29-4.17)) and less personal sleep (adjusted OR 0.22; 95% CI 0.07-0.71). Fathers of unsettled infants reported greater anger towards their infant and increased depressive symptoms by 4 months infant age, with these symptoms persisting 2 months later. Evidence-based interventions are needed for these fathers. © 2016 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

Stress and Personal Resource as Predictors of the Adjustment of Parents to Autistic Children: A Multivariate Model

ERIC Educational Resources Information Center

Siman-Tov, Ayelet; Kaniel, Shlomo

2011-01-01

The research validates a multivariate model that predicts parental adjustment to coping successfully with an autistic child. The model comprises four elements: parental stress, parental resources, parental adjustment and the child's autism symptoms. 176 parents of children aged between 6 to 16 diagnosed with PDD answered several questionnaires…

Adjustment in Mothers of Children with Asperger Syndrome: An Application of the Double ABCX Model of Family Adjustment

ERIC Educational Resources Information Center

Pakenham, Kenneth I.; Samios, Christina; Sofronoff, Kate

2005-01-01

The present study examined the applicability of the double ABCX model of family adjustment in explaining maternal adjustment to caring for a child diagnosed with Asperger syndrome. Forty-seven mothers completed questionnaires at a university clinic while their children were participating in an anxiety intervention. The children were aged between…

Self-esteem, ethnic identity, and behavioral adjustment among Anglo and Chicano adolescents in West Texas.

PubMed

Grossman, B; Wirt, R; Davids, A

1985-03-01

This study provides a comparison of similarities and differences with respect to ethnic identity between Anglo and Chicano adolescents from Texas. A path analysis model was used to test a theoretical assumption concerning proposed antecedents and consequences of self-esteem. Research instruments included the Rosenberg Self Esteem Scale, the Semantic Differential (scales for Myself and My Ethnic Group) and the McGuire White Measure of Social Status. Results were consistent with the interpretation that there is a relationship between being Chicano and having lower self-esteem, lower behavioral adjustment, and higher ethnic esteem. The prediction that ethnic esteem would mediate between ethnic group and self-esteem was upheld. Variables such as ethnic group membership per se and sex appear as or more important to the prediction of behavioral level. Clinical implications include recognizing that Chicanos low in self-esteem or behavioral adjustment should not automatically be considered unusual. The problems faced by this group are considered as having something in common with other groups of people who have more problems, lesser status, fewer resources, and fewer sources of available help.

Hospital and Community Characteristics Associated With Pediatric Direct Admission to Hospital.

PubMed

Leyenaar, JoAnna K; Shieh, Meng-Shiou; Lagu, Tara; Pekow, Penelope S; Lindenauer, Peter K

2017-10-27

One quarter of pediatric hospitalizations begin as direct admissions, defined as hospitalization without receiving care in the hospital's emergency department (ED). Direct admission rates are highly variable across hospitals, yet previous studies have not examined reasons for this variation. We aimed to determine the relationships between hospital and community factors and pediatric direct admission rates, and to evaluate the degree to which these characteristics explain variation in risk-adjusted direct admission rates. We conducted a cross-sectional study of the Healthcare Cost and Utilization Project's Kids Inpatient Database, American Hospital Association Database, and Area Health Resource File, including children <18 years of age who were admitted for a medical hospitalization in states contributing data to all data sets. Using hierarchical generalized linear modeling, we generated risk-adjusted direct admission rates and used generalized linear models to assess the association of hospital and community characteristics with these risk-adjusted rates. We included 211,458 children discharged from 933 hospitals and 26 states; 20.2% were admitted directly. One-fifth of the variance in risk-adjusted direct admission rates was attributed to observed hospital and community factors. The greatest proportion of this explained variance was related to ED volume (37%), volume of pediatric hospitalizations (27%), and size of the pediatrician workforce (12%). Direct admission rates were associated with several hospital and community characteristics, but the majority of variation in hospitals' direct admission rates was not explained by these factors. These findings suggest opportunities for diverse hospital types to develop the infrastructure and communication systems necessary to support pediatric direct admissions. Copyright © 2017 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

The volume-mortality relation for radical cystectomy in England: retrospective analysis of hospital episode statistics

PubMed Central

Bottle, Alex; Darzi, Ara W; Athanasiou, Thanos; Vale, Justin A

2010-01-01

Objectives To investigate the relation between volume and mortality after adjustment for case mix for radical cystectomy in the English healthcare setting using improved statistical methodology, taking into account the institutional and surgeon volume effects and institutional structural and process of care factors. Design Retrospective analysis of hospital episode statistics using multilevel modelling. Setting English hospitals carrying out radical cystectomy in the seven financial years 2000/1 to 2006/7. Participants Patients with a primary diagnosis of cancer undergoing an inpatient elective cystectomy. Main outcome measure Mortality within 30 days of cystectomy. Results Compared with low volume institutions, medium volume ones had a significantly higher odds of in-hospital and total mortality: odds ratio 1.72 (95% confidence interval 1.00 to 2.98, P=0.05) and 1.82 (1.08 to 3.06, P=0.02). This was only seen in the final model, which included adjustment for structural and processes of care factors. The surgeon volume-mortality relation showed weak evidence of reduced odds of in-hospital mortality (by 35%) for the high volume surgeons, although this did not reach statistical significance at the 5% level. Conclusions The relation between case volume and mortality after radical cystectomy for bladder cancer became evident only after adjustment for structural and process of care factors, including staffing levels of nurses and junior doctors, in addition to case mix. At least for this relatively uncommon procedure, adjusting for these confounders when examining the volume-outcome relation is critical before considering centralisation of care to a few specialist institutions. Outcomes other than mortality, such as functional morbidity and disease recurrence may ultimately influence towards centralising care. PMID:20305302

The Next Generation of Mars-GRAM and Its Role in the Autonomous Aerobraking Development Plan

NASA Technical Reports Server (NTRS)

Justh, Hilary L.; Justus, Carl G.; Ramey, Holly S.

2011-01-01

The Mars Global Reference Atmospheric Model (Mars-GRAM) is an engineering-level atmospheric model widely used for diverse mission applications. Mars-GRAM 2010 is currently being used to develop the onboard atmospheric density estimator that is part of the Autonomous Aerobraking Development Plan. In previous versions, Mars-GRAM was less than realistic when used for sensitivity studies for Thermal Emission Spectrometer (TES) MapYear=0 and large optical depth values, such as tau=3. A comparison analysis has been completed between Mars-GRAM, TES and data from the Planetary Data System (PDS) resulting in updated coefficients for the functions relating density, latitude, and longitude of the sun. The adjustment factors are expressed as a function of height (z), Latitude (Lat) and areocentric solar longitude (Ls). The latest release of Mars-GRAM 2010 includes these adjustment factors that alter the in-put data from MGCM and MTGCM for the Mapping Year 0 (user-controlled dust) case. The greatest adjustment occurs at large optical depths such as tau greater than 1. The addition of the adjustment factors has led to better correspondence to TES Limb data from 0-60 km as well as better agreement with MGS, ODY and MRO data at approximately 90-135 km. Improved simulations utilizing Mars-GRAM 2010 are vital to developing the onboard atmospheric density estimator for the Autonomous Aerobraking Development Plan. Mars-GRAM 2010 was not the only planetary GRAM utilized during phase 1 of this plan; Titan-GRAM and Venus-GRAM were used to generate density data sets for Aerobraking Design Reference Missions. These data sets included altitude profiles (both vertical and along a trajectory), GRAM perturbations (tides, gravity waves, etc.) and provided density and scale height values for analysis by other Autonomous Aero-braking team members.

Do pregnancy characteristics contribute to rising childhood cancer incidence rates in the United States?

PubMed

Kehm, Rebecca D; Osypuk, Theresa L; Poynter, Jenny N; Vock, David M; Spector, Logan G

2018-03-01

Since 1975, childhood cancer incidence rates have gradually increased in the United States; however, few studies have conducted analyses across time to unpack this temporal rise. The aim of this study was to test the hypothesis that increasing cancer incidence rates are due to secular trends in pregnancy characteristics that are established risk factors for childhood cancer incidence including older maternal age, higher birthweight, and lower birth order. We also considered temporal trends in sociodemographic characteristics including race/ethnicity and poverty. We conducted a time series county-level ecologic analysis using linked population-based data from Surveillance, Epidemiology, and End Results cancer registries (1975-2013), birth data from the National Center for Health Statistics (1970-2013), and sociodemographic data from the US Census (1970-2010). We estimated unadjusted and adjusted average annual percent changes (AAPCs) in incidence of combined (all diagnoses) and individual types of cancer among children, ages 0-4 years, from Poisson mixed models. There was a statistically significant unadjusted temporal rise in incidence of combined childhood cancers (AAPC = 0.71%; 95% CI = 0.55-0.86), acute lymphoblastic leukemia (0.78%; 0.49-1.07), acute myeloid leukemia (1.86%; 1.13-2.59), central nervous system tumors (1.31%; 0.94-1.67), and hepatoblastoma (2.70%; 1.68-3.72). Adjustment for county-level maternal age reduced estimated AAPCs between 8% (hepatoblastoma) and 55% (combined). However, adjustment for other county characteristics did not attenuate AAPCs, and AAPCs remained significantly above 0% in models fully adjusted for county-level characteristics. Although rising maternal age may account for some of the increase in childhood cancer incidence over time, other factors, not considered in this analysis, may also contribute to temporal trends. © 2017 Wiley Periodicals, Inc.

Urinary bisphenol A concentration and risk of future coronary artery disease in apparently healthy men and women.

PubMed

Melzer, David; Osborne, Nicholas J; Henley, William E; Cipelli, Riccardo; Young, Anita; Money, Cathryn; McCormack, Paul; Luben, Robert; Khaw, Kay-Tee; Wareham, Nicholas J; Galloway, Tamara S

2012-03-27

The endocrine-disrupting chemical bisphenol A (BPA) is widely used in food and beverage packaging. Higher urinary BPA concentrations were cross-sectionally associated with heart disease in National Health and Nutrition Examination Survey (NHANES) 2003-2004 and NHANES 2005-2006, independent of traditional risk factors. We included 758 incident coronary artery disease (CAD) cases and 861 controls followed for 10.8 years from the European Prospective Investigation of Cancer-Norfolk UK. Respondents aged 40 to 74 years and free of CAD, stroke, or diabetes mellitus provided baseline spot urine samples. Urinary BPA concentrations (median value, 1.3 ng/mL) were low. Per-SD (4.56 ng/mL) increases in urinary BPA concentration were associated with incident CAD in age-, sex-, and urinary creatinine-adjusted models (n=1919; odds ratio=1.13; 95% confidence interval, 1.02-1.24; P=0.017). With CAD risk factor adjustment (including education, occupational social class, body mass index category, systolic blood pressure, lipid concentrations, and exercise), the estimate was similar but narrowly missed 2-sided significance (n=1744; odds ratio=1.11; 95% confidence interval, 1.00-1.23; P=0.058). Sensitivity analyses with the fully adjusted model, excluding those with early CAD (<3-year follow-up), body mass index >30, or abnormal renal function or with additional adjustment for vitamin C, C-reactive protein, or alcohol consumption, all produced similar estimates, and all showed associations at P≤0.05. Associations between higher BPA exposure (reflected in higher urinary concentrations) and incident CAD during >10 years of follow-up showed trends similar to previously reported cross-sectional findings in the more highly exposed NHANES respondents. Further work is needed to accurately estimate the prospective exposure-response curve and to establish the underlying mechanisms.

Recurrent Stroke in Minor Ischemic Stroke or Transient Ischemic Attack With Metabolic Syndrome and/or Diabetes Mellitus.

PubMed

Chen, Weiqi; Pan, Yuesong; Jing, Jing; Zhao, Xingquan; Liu, Liping; Meng, Xia; Wang, Yilong; Wang, Yongjun

2017-06-01

We aimed to determine the risk conferred by metabolic syndrome (METS) and diabetes mellitus (DM) to recurrent stroke in patients with minor ischemic stroke or transient ischemic attack from the CHANCE (Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events) trial. In total, 3044 patients were included. Patients were stratified into 4 groups: neither, METS only, DM only, or both. METS was defined using the Chinese Diabetes Society (CDS) and International Diabetes Foundation (IDF) definitions. The primary outcome was new stroke (including ischemic and hemorrhagic) at 90 days. A multivariable Cox regression model was used to assess the relationship of METS and DM status to the risk of recurrent stroke adjusted for potential covariates. Using the CDS criteria of METS, 53.2%, 17.2%, 19.8%, and 9.8% of patients were diagnosed as neither, METS only, DM only, and both, respectively. After 90 days of follow-up, there were 299 new strokes (293 ischemic, 6 hemorrhagic). Patients with DM only (16.1% versus 6.8%; adjusted hazard ratio 2.50, 95% CI 1.89-3.39) and both (17.1% versus 6.8%; adjusted hazard ratio 2.76, 95% CI 1.98-3.86) had significantly increased rates of recurrent stroke. No interaction effect of antiplatelet therapy by different METS or DM status for the risk of recurrent stroke ( P =0.82 for interaction in the fully adjusted model of CDS) was observed. Using the METS (IDF) criteria demonstrated similar results. Concurrent METS and DM was associated with an increased risk of recurrent stroke in patients with minor stroke and transient ischemic attack. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Relationship Between Attention-Deficit/Hyperactivity Disorder Care and Medication Continuity.

PubMed

Brinkman, William B; Baum, Rebecca; Kelleher, Kelly J; Peugh, James; Gardner, William; Lichtenstein, Phil; Langberg, Joshua; Epstein, Jeffery N

2016-04-01

To describe the relationships between attention-deficit/hyperactivity disorder (ADHD) care practices and subsequent medication use. A retrospective cohort from a random sample of medical records in 50 pediatric practices with 188 providers, including 1,352 children who started ADHD medication, was studied. Independent variables included physician behaviors related to medication titration and monitoring of treatment response. Primary outcomes were number of days covered with ADHD medication during the first year of treatment and time from starting medicine to the first 30-day gap in medication supply. Multilevel modeling and Cox proportional hazards regression models were conducted. Children had an average medication supply of 217 days in the first year. Half experienced a 30-day gap in medication supply in the first 3 months. Nearly three-fourths had a medication adjustment in the first year with the first adjustment usually being a dosage change. The average time to the first medication adjustment was over 3 months. Physician's first contact with parents occurred in the first month of treatment for less than half, with the average time being over 2 months. Little variation related to ADHD care quality was accounted for at the physician level. Early titration and early contact were related to greater medication supply and continuity of treatment. Earlier physician-delivered ADHD care (e.g., contact with parent after starting medication and medication adjustment) is related to greater medication supply and continuity. It remains to be determined whether interventions that improve the quality of titration and monitoring practices for children with ADHD would also improve medication continuity. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Modeling to predict pilot performance during CDTI-based in-trail following experiments

NASA Technical Reports Server (NTRS)

Sorensen, J. A.; Goka, T.

1984-01-01

A mathematical model was developed of the flight system with the pilot using a cockpit display of traffic information (CDTI) to establish and maintain in-trail spacing behind a lead aircraft during approach. Both in-trail and vertical dynamics were included. The nominal spacing was based on one of three criteria (Constant Time Predictor; Constant Time Delay; or Acceleration Cue). This model was used to simulate digitally the dynamics of a string of multiple following aircraft, including response to initial position errors. The simulation was used to predict the outcome of a series of in-trail following experiments, including pilot performance in maintaining correct longitudinal spacing and vertical position. The experiments were run in the NASA Ames Research Center multi-cab cockpit simulator facility. The experimental results were then used to evaluate the model and its prediction accuracy. Model parameters were adjusted, so that modeled performance matched experimental results. Lessons learned in this modeling and prediction study are summarized.

Data Assimilation Cycling for Weather Analysis

NASA Technical Reports Server (NTRS)

Tran, Nam; Li, Yongzuo; Fitzpatrick, Patrick

2008-01-01

This software package runs the atmospheric model MM5 in data assimilation cycling mode to produce an optimized weather analysis, including the ability to insert or adjust a hurricane vortex. The program runs MM5 through a cycle of short forecasts every three hours where the vortex is adjusted to match the observed hurricane location and storm intensity. This technique adjusts the surrounding environment so that the proper steering current and environmental shear are achieved. MM5cycle uses a Cressman analysis to blend observation into model fields to get a more accurate weather analysis. Quality control of observations is also done in every cycle to remove bad data that may contaminate the analysis. This technique can assimilate and propagate data in time from intermittent and infrequent observations while maintaining the atmospheric field in a dynamically balanced state. The software consists of a C-shell script (MM5cycle.driver) and three FORTRAN programs (splitMM5files.F, comRegrid.F, and insert_vortex.F), and are contained in the pre-processor component of MM5 called "Regridder." The model is first initialized with data from a global model such as the Global Forecast System (GFS), which also provides lateral boundary conditions. These data are separated into single-time files using splitMM5.F. The hurricane vortex is then bogussed in the correct location and with the correct wind field using insert_vortex.F. The modified initial and boundary conditions are then recombined into the model fields using comRegrid.F. The model then makes a three-hour forecast. The three-hour forecast data from MM5 now become the analysis for the next short forecast run, where the vortex will again be adjusted. The process repeats itself until the desired time of analysis is achieved. This code can also assimilate observations if desired.

Optimizing Surgical Quality Datasets to Care for Older Adults: Lessons from the American College of Surgeons NSQIP Geriatric Surgery Pilot.

PubMed

Berian, Julia R; Zhou, Lynn; Hornor, Melissa A; Russell, Marcia M; Cohen, Mark E; Finlayson, Emily; Ko, Clifford Y; Robinson, Thomas N; Rosenthal, Ronnie A

2017-12-01

Surgical quality datasets can be better tailored toward older adults. The American College of Surgeons (ACS) NSQIP Geriatric Surgery Pilot collected risk factors and outcomes in 4 geriatric-specific domains: cognition, decision-making, function, and mobility. This study evaluated the contributions of geriatric-specific factors to risk adjustment in modeling 30-day outcomes and geriatric-specific outcomes (postoperative delirium, new mobility aid use, functional decline, and pressure ulcers). Using ACS NSQIP Geriatric Surgery Pilot data (January 2014 to December 2016), 7 geriatric-specific risk factors were evaluated for selection in 14 logistic models (morbidities/mortality) in general-vascular and orthopaedic surgery subgroups. Hierarchical models evaluated 4 geriatric-specific outcomes, adjusting for hospitals-level effects and including Bayesian-type shrinkage, to estimate hospital performance. There were 36,399 older adults who underwent operations at 31 hospitals in the ACS NSQIP Geriatric Surgery Pilot. Geriatric-specific risk factors were selected in 10 of 14 models in both general-vascular and orthopaedic surgery subgroups. After risk adjustment, surrogate consent (odds ratio [OR] 1.5; 95% CI 1.3 to 1.8) and use of a mobility aid (OR 1.3; 95% CI 1.1 to 1.4) increased the risk for serious morbidity or mortality in the general-vascular cohort. Geriatric-specific factors were selected in all 4 geriatric-specific outcomes models. Rates of geriatric-specific outcomes were: postoperative delirium in 12.1% (n = 3,650), functional decline in 42.9% (n = 13,000), new mobility aid in 29.7% (n = 9,257), and new or worsened pressure ulcers in 1.7% (n = 527). Geriatric-specific risk factors are important for patient-centered care and contribute to risk adjustment in modeling traditional and geriatric-specific outcomes. To provide optimal patient care for older adults, surgical datasets should collect measures that address cognition, decision-making, mobility, and function. Copyright © 2017 American College of Surgeons. All rights reserved.

Analytical fitting model for rough-surface BRDF.

PubMed

Renhorn, Ingmar G E; Boreman, Glenn D

2008-08-18

A physics-based model is developed for rough surface BRDF, taking into account angles of incidence and scattering, effective index, surface autocovariance, and correlation length. Shadowing is introduced on surface correlation length and reflectance. Separate terms are included for surface scatter, bulk scatter and retroreflection. Using the FindFit function in Mathematica, the functional form is fitted to BRDF measurements over a wide range of incident angles. The model has fourteen fitting parameters; once these are fixed, the model accurately describes scattering data over two orders of magnitude in BRDF without further adjustment. The resulting analytical model is convenient for numerical computations.

Epidemiology of Noninvasive Ventilation in Pediatric Cardiac ICUs.

PubMed

Romans, Ryan A; Schwartz, Steven M; Costello, John M; Chanani, Nikhil K; Prodhan, Parthak; Gazit, Avihu Z; Smith, Andrew H; Cooper, David S; Alten, Jeffrey; Mistry, Kshitij P; Zhang, Wenying; Donohue, Janet E; Gaies, Michael

2017-10-01

To describe the epidemiology of noninvasive ventilation therapy for patients admitted to pediatric cardiac ICUs and to assess practice variation across hospitals. Retrospective cohort study using prospectively collected clinical registry data. Pediatric Cardiac Critical Care Consortium clinical registry. Patients admitted to cardiac ICUs at PC4 hospitals. None. We analyzed all cardiac ICU encounters that included any respiratory support from October 2013 to December 2015. Noninvasive ventilation therapy included high flow nasal cannula and positive airway pressure support. We compared patient and, when relevant, perioperative characteristics of those receiving noninvasive ventilation to all others. Subgroup analysis was performed on neonates and infants undergoing major cardiovascular surgery. To examine duration of respiratory support, we created a casemix-adjustment model and calculated adjusted mean durations of total respiratory support (mechanical ventilation + noninvasive ventilation), mechanical ventilation, and noninvasive ventilation. We compared adjusted duration of support across hospitals. The cohort included 8,940 encounters from 15 hospitals: 3,950 (44%) received noninvasive ventilation and 72% were neonates and infants. Medical encounters were more likely to include noninvasive ventilation than surgical. In surgical neonates and infants, 2,032 (55%) received postoperative noninvasive ventilation. Neonates, extracardiac anomalies, single ventricle, procedure complexity, preoperative respiratory support, mechanical ventilation duration, and postoperative disease severity were associated with noninvasive ventilation therapy (p < 0.001 for all). Across hospitals, noninvasive ventilation use ranged from 32% to 65%, and adjusted mean noninvasive ventilation duration ranged from 1 to 4 days (3-d observed mean). Duration of total adjusted respiratory support was more strongly correlated with duration of mechanical ventilation compared with noninvasive ventilation (Pearson r = 0.93 vs 0.71, respectively). Noninvasive ventilation use is common in cardiac ICUs, especially in patients admitted for medical conditions, infants, and those undergoing high complexity surgery. We observed wide variation in noninvasive ventilation use across hospitals, though the primary driver of total respiratory support time seems to be duration of mechanical ventilation.

The Effect of Age on Characteristics and Mortality of Intracerebral Hemorrhage in the Oldest-Old.

PubMed

Forti, Paola; Maioli, Fabiola; Domenico Spampinato, Michele; Barbara, Carlotta; Nativio, Valeria; Coveri, Maura; Zoli, Marco; Simonetti, Luigi; Di Pasquale, Giuseppe; Procaccianti, Gaetano

2016-01-01

Incidence of acute intracerebral hemorrhage (ICH) increases with age, but there is a lack of information about ICH characteristics in the oldest-old (age ≥85 years). In particular, there is a need for information about hematoma volume, which is included in most clinical scales for prediction of mortality in ICH patients. Many of these scales also assume that, independent of ICH characteristics, the oldest-old have a higher mortality than younger elderly patients (age 65-74 years). However, supporting evidence from cohort studies is limited. We investigated ICH characteristics of oldest-old subjects compared to young (<65 years), young-old (65-74 years) and old-old (75-84 years) subjects. We also investigated whether age is an independent mortality predictor in elderly (age ≥65 years) subjects with acute ICH. We retrospectively collected clinical and neuroimaging data of 383 subjects (age 34-104 years) with acute supratentorial primary ICH who were admitted to an Italian Stroke Unit (SU) between October 2007 and December 2014. Measured ICH characteristics included hematoma location, volume and intraventricular extension of hemorrhage on admission CT scan; admission Glasgow Coma Scale ≤8 and hematoma expansion (HE) measured on follow-up CT-scans obtained after 24 h. General linear models and logistic models were used to investigate the association of age with ICH characteristics. These models were adjusted for pre-admission characteristics, hematoma location and time from symptom onset to admission CT scan. Limited to elderly subjects, Cox models were used to investigate the association of age with in-SU and 1-year mortality: the model for in-SU mortality adjusted for pre-admission and ICH admission characteristics and the model for 1-year mortality additionally adjusted for functional status and disposition at SU discharge. Independent of pre-admission characteristics, hematoma location and time from symptom onset to admission CT-scan, oldest-old subjects had the highest admission hematoma volume (p < 0.01). Age was unrelated to all other ICH characteristics including HE. In elderly patients, multivariable adjusted risk of in-SU and 1-year mortality did not vary across age categories. Oldest-old subjects with acute supratentorial ICH have higher admission hematoma volume than young and young-old subjects but do not differ for other ICH characteristics. When taking into account confounding from ICH characteristics, risk of in-SU and 1-year mortality in elderly subjects with acute supratentorial ICH does not differ across age categories. Our findings question use of age as an independent criterion for stratification of mortality risk in elderly subjects with acute ICH. © 2016 S. Karger AG, Basel.

The Impact of Disability and Social Determinants of Health on Condition-Specific Readmissions beyond Medicare Risk Adjustments: A Cohort Study.

PubMed

Meddings, Jennifer; Reichert, Heidi; Smith, Shawna N; Iwashyna, Theodore J; Langa, Kenneth M; Hofer, Timothy P; McMahon, Laurence F

2017-01-01

Readmission rates after pneumonia, heart failure, and acute myocardial infarction hospitalizations are risk-adjusted for age, gender, and medical comorbidities and used to penalize hospitals. To assess the impact of disability and social determinants of health on condition-specific readmissions beyond current risk adjustment. Retrospective cohort study of Medicare patients using 1) linked Health and Retirement Study-Medicare claims data (HRS-CMS) and 2) Healthcare Cost and Utilization Project State Inpatient Databases (Florida, Washington) linked with ZIP Code-level measures from the Census American Community Survey (ACS-HCUP). Multilevel logistic regression models assessed the impact of disability and selected social determinants of health on readmission beyond current risk adjustment. Outcomes measured were readmissions ≤30 days after hospitalizations for pneumonia, heart failure, or acute myocardial infarction. HRS-CMS models included disability measures (activities of daily living [ADL] limitations, cognitive impairment, nursing home residence, home healthcare use) and social determinants of health (spouse, children, wealth, Medicaid, race). ACS-HCUP model measures were ZIP Code-percentage of residents ≥65 years of age with ADL difficulty, spouse, income, Medicaid, and patient-level and hospital-level race. For pneumonia, ≥3 ADL difficulties (OR 1.61, CI 1.079-2.391) and prior home healthcare needs (OR 1.68, CI 1.204-2.355) increased readmission in HRS-CMS models (N = 1631); ADL difficulties (OR 1.20, CI 1.063-1.352) and 'other' race (OR 1.14, CI 1.001-1.301) increased readmission in ACS-HCUP models (N = 27,297). For heart failure, children (OR 0.66, CI 0.437-0.984) and wealth (OR 0.53, CI 0.349-0.787) lowered readmission in HRS-CMS models (N = 2068), while black (OR 1.17, CI 1.056-1.292) and 'other' race (OR 1.14, CI 1.036-1.260) increased readmission in ACS-HCUP models (N = 37,612). For acute myocardial infarction, nursing home status (OR 4.04, CI 1.212-13.440) increased readmission in HRS-CMS models (N = 833); 'other' patient-level race (OR 1.18, CI 1.012-1.385) and hospital-level race (OR 1.06, CI 1.001-1.125) increased readmission in ACS-HCUP models (N = 17,496). Disability and social determinants of health influence readmission risk when added to the current Medicare risk adjustment models, but the effect varies by condition.

Accounting for individual differences and timing of events: estimating the effect of treatment on criminal convictions in heroin users

PubMed Central

2014-01-01

Background The reduction of crime is an important outcome of opioid maintenance treatment (OMT). Criminal intensity and treatment regimes vary among OMT patients, but this is rarely adjusted for in statistical analyses, which tend to focus on cohort incidence rates and rate ratios. The purpose of this work was to estimate the relationship between treatment and criminal convictions among OMT patients, adjusting for individual covariate information and timing of events, fitting time-to-event regression models of increasing complexity. Methods National criminal records were cross linked with treatment data on 3221 patients starting OMT in Norway 1997–2003. In addition to calculating cohort incidence rates, criminal convictions was modelled as a recurrent event dependent variable, and treatment a time-dependent covariate, in Cox proportional hazards, Aalen’s additive hazards, and semi-parametric additive hazards regression models. Both fixed and dynamic covariates were included. Results During OMT, the number of days with criminal convictions for the cohort as a whole was 61% lower than when not in treatment. OMT was associated with reduced number of days with criminal convictions in all time-to-event regression models, but the hazard ratio (95% CI) was strongly attenuated when adjusting for covariates; from 0.40 (0.35, 0.45) in a univariate model to 0.79 (0.72, 0.87) in a fully adjusted model. The hazard was lower for females and decreasing with older age, while increasing with high numbers of criminal convictions prior to application to OMT (all p < 0.001). The strongest predictors were level of criminal activity prior to entering into OMT, and having a recent criminal conviction (both p < 0.001). The effect of several predictors was significantly time-varying with their effects diminishing over time. Conclusions Analyzing complex observational data regarding to fixed factors only overlooks important temporal information, and naïve cohort level incidence rates might result in biased estimates of the effect of interventions. Applying time-to-event regression models, properly adjusting for individual covariate information and timing of various events, allows for more precise and reliable effect estimates, as well as painting a more nuanced picture that can aid health care professionals and policy makers. PMID:24886472

Ambient Air Pollution and Cancer Mortality in the Cancer Prevention Study II

PubMed Central

Krewski, Daniel; Diver, W. Ryan; Pope, C. Arden; Burnett, Richard T.; Jerrett, Michael; Marshall, Julian D.; Gapstur, Susan M.

2017-01-01

Background: The International Agency for Research on Cancer classified both outdoor air pollution and airborne particulate matter as carcinogenic to humans (Group 1) for lung cancer. There may be associations with cancer at other sites; however, the epidemiological evidence is limited. Objective: The aim of this study was to clarify whether ambient air pollution is associated with specific types of cancer other than lung cancer by examining associations of ambient air pollution with nonlung cancer death in the Cancer Prevention Study II (CPS-II). Methods: Analysis included 623,048 CPS-II participants who were followed for 22 y (1982–2004). Modeled estimates of particulate matter with aerodynamic diameter <2.5µm (PM2.5) (1999–2004), nitrogen dioxide (NO2) (2006), and ozone (O3) (2002–2004) concentrations were linked to the participant residence at enrollment. Cox proportional hazards models were used to estimate associations per each fifth percentile–mean increment with cancer mortality at 29 anatomic sites, adjusted for individual and ecological covariates. Results: We observed 43,320 nonlung cancer deaths. PM2.5 was significantly positively associated with death from cancers of the kidney {adjusted hazard ratio (HR) per 4.4 μg/m3=1.14 [95% confidence interval (CI): 1.03, 1.27]} and bladder [HR=1.13 (95% CI: 1.03, 1.23)]. NO2 was positively associated with colorectal cancer mortality [HR per 6.5 ppb=1.06 (95% CI: 1.02, 1.10). The results were similar in two-pollutant models including PM2.5 and NO2 and in three-pollutant models with O3. We observed no statistically significant positive associations with death from other types of cancer based on results from adjusted models. Conclusions: The results from this large prospective study suggest that ambient air pollution was not associated with death from most nonlung cancers, but associations with kidney, bladder, and colorectal cancer death warrant further investigation. https://doi.org/10.1289/EHP1249 PMID:28886601

State estimation and prediction using clustered particle filters.

PubMed

Lee, Yoonsang; Majda, Andrew J

2016-12-20

Particle filtering is an essential tool to improve uncertain model predictions by incorporating noisy observational data from complex systems including non-Gaussian features. A class of particle filters, clustered particle filters, is introduced for high-dimensional nonlinear systems, which uses relatively few particles compared with the standard particle filter. The clustered particle filter captures non-Gaussian features of the true signal, which are typical in complex nonlinear dynamical systems such as geophysical systems. The method is also robust in the difficult regime of high-quality sparse and infrequent observations. The key features of the clustered particle filtering are coarse-grained localization through the clustering of the state variables and particle adjustment to stabilize the method; each observation affects only neighbor state variables through clustering and particles are adjusted to prevent particle collapse due to high-quality observations. The clustered particle filter is tested for the 40-dimensional Lorenz 96 model with several dynamical regimes including strongly non-Gaussian statistics. The clustered particle filter shows robust skill in both achieving accurate filter results and capturing non-Gaussian statistics of the true signal. It is further extended to multiscale data assimilation, which provides the large-scale estimation by combining a cheap reduced-order forecast model and mixed observations of the large- and small-scale variables. This approach enables the use of a larger number of particles due to the computational savings in the forecast model. The multiscale clustered particle filter is tested for one-dimensional dispersive wave turbulence using a forecast model with model errors.

State estimation and prediction using clustered particle filters

PubMed Central

Lee, Yoonsang; Majda, Andrew J.

2016-01-01

Particle filtering is an essential tool to improve uncertain model predictions by incorporating noisy observational data from complex systems including non-Gaussian features. A class of particle filters, clustered particle filters, is introduced for high-dimensional nonlinear systems, which uses relatively few particles compared with the standard particle filter. The clustered particle filter captures non-Gaussian features of the true signal, which are typical in complex nonlinear dynamical systems such as geophysical systems. The method is also robust in the difficult regime of high-quality sparse and infrequent observations. The key features of the clustered particle filtering are coarse-grained localization through the clustering of the state variables and particle adjustment to stabilize the method; each observation affects only neighbor state variables through clustering and particles are adjusted to prevent particle collapse due to high-quality observations. The clustered particle filter is tested for the 40-dimensional Lorenz 96 model with several dynamical regimes including strongly non-Gaussian statistics. The clustered particle filter shows robust skill in both achieving accurate filter results and capturing non-Gaussian statistics of the true signal. It is further extended to multiscale data assimilation, which provides the large-scale estimation by combining a cheap reduced-order forecast model and mixed observations of the large- and small-scale variables. This approach enables the use of a larger number of particles due to the computational savings in the forecast model. The multiscale clustered particle filter is tested for one-dimensional dispersive wave turbulence using a forecast model with model errors. PMID:27930332

Identifying unusual performance in Australian and New Zealand intensive care units from 2000 to 2010.

PubMed

Solomon, Patricia J; Kasza, Jessica; Moran, John L

2014-04-22

The Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database (APD) collects voluntary data on patient admissions to Australian and New Zealand intensive care units (ICUs). This paper presents an in-depth statistical analysis of risk-adjusted mortality of ICU admissions from 2000 to 2010 for the purpose of identifying ICUs with unusual performance. A cohort of 523,462 patients from 144 ICUs was analysed. For each ICU, the natural logarithm of the standardised mortality ratio (log-SMR) was estimated from a risk-adjusted, three-level hierarchical model. This is the first time a three-level model has been fitted to such a large ICU database anywhere. The analysis was conducted in three stages which included the estimation of a null distribution to describe usual ICU performance. Log-SMRs with appropriate estimates of standard errors are presented in a funnel plot using 5% false discovery rate thresholds. False coverage-statement rate confidence intervals are also presented. The observed numbers of deaths for ICUs identified as unusual are compared to the predicted true worst numbers of deaths under the model for usual ICU performance. Seven ICUs were identified as performing unusually over the period 2000 to 2010, in particular, demonstrating high risk-adjusted mortality compared to the majority of ICUs. Four of the seven were ICUs in private hospitals. Our three-stage approach to the analysis detected outlying ICUs which were not identified in a conventional (single) risk-adjusted model for mortality using SMRs to compare ICUs. We also observed a significant linear decline in mortality over the decade. Distinct yearly and weekly respiratory seasonal effects were observed across regions of Australia and New Zealand for the first time. The statistical approach proposed in this paper is intended to be used for the review of observed ICU and hospital mortality. Two important messages from our study are firstly, that comprehensive risk-adjustment is essential in modelling patient mortality for comparing performance, and secondly, that the appropriate statistical analysis is complicated.

Sleep Duration and Quality in Relation to Autonomic Nervous System Measures: The Multi-Ethnic Study of Atherosclerosis (MESA)

PubMed Central

Castro-Diehl, Cecilia; Diez Roux, Ana V.; Redline, Susan; Seeman, Teresa; McKinley, Paula; Sloan, Richard; Shea, Steven

2016-01-01

Study Objectives: Short sleep duration and poor sleep quality are associated with adverse cardiovascular outcomes. Potential pathophysiological mechanisms include sleep-associated alterations in the autonomic nervous system. The objective of this study was to examine the associations of shorter sleep duration and poorer sleep quality with markers of autonomic tone: heart rate (HR), high-frequency HR variability (HF-HRV) and salivary amylase. Methods: Cross-sectional analysis of data from actigraphy-based measures of sleep duration and efficiency and responses to a challenge protocol obtained from 527 adult participants in the Multi-Ethnic Study of Atherosclerosis. Results: Participants who slept fewer than 6 h per night (compared to those who slept 7 h or more per night) had higher baseline HR (fully adjusted model 0.05 log beats/min, 95% confidence interval [CI] 0.01, 0.09) and greater HR orthostatic reactivity (fully adjusted model 0.02 log beats/min, 95% CI 0.002, 0.023). Participants who slept 6 to less than 7 h/night (compared to those who slept 7 h or more per night) had lower baseline HF-HRV (fully adjusted model −0.31 log msec2, 95% CI −0.60, −0.14). Participants with low sleep efficiency had lower baseline HF-HRV than those with higher sleep efficiency (fully adjusted model −0.59 log msec2, 95% CI −1.03, −0.15). Participants with low sleep efficiency had higher baseline levels of amylase than those with higher sleep efficiency (fully adjusted model 0.45 log U/mL, 95% CI 0.04, 0.86). Conclusions: Short sleep duration, low sleep efficiency, and insomnia combined with short sleep duration were associated with markers of autonomic tone that indicate lower levels of cardiac parasympathetic (vagal) tone and/or higher levels of sympathetic tone. Citation: Castro-Diehl C, Roux AV, Redline S, Seeman T, McKinley P, Sloan R, Shea S. Sleep duration and quality in relation to autonomic nervous system measures: the Multi-Ethnic Study of Atherosclerosis (MESA). SLEEP 2016;39(11):1927–1940. PMID:27568797

An Efficient Bundle Adjustment Model Based on Parallax Parametrization for Environmental Monitoring

NASA Astrophysics Data System (ADS)

Chen, R.; Sun, Y. Y.; Lei, Y.

2017-12-01

With the rapid development of Unmanned Aircraft Systems (UAS), more and more research fields have been successfully equipped with this mature technology, among which is environmental monitoring. One difficult task is how to acquire accurate position of ground object in order to reconstruct the scene more accurate. To handle this problem, we combine bundle adjustment method from Photogrammetry with parallax parametrization from Computer Vision to create a new method call APCP (aerial polar-coordinate photogrammetry). One impressive advantage of this method compared with traditional method is that the 3-dimensional point in space is represented using three angles (elevation angle, azimuth angle and parallax angle) rather than the XYZ value. As the basis for APCP, bundle adjustment could be used to optimize the UAS sensors' pose accurately, reconstruct the 3D models of environment, thus serving as the criterion of accurate position for monitoring. To verity the effectiveness of the proposed method, we test on several UAV dataset obtained by non-metric digital cameras with large attitude angles, and we find that our methods could achieve 1 or 2 times better efficiency with no loss of accuracy than traditional ones. For the classical nonlinear optimization of bundle adjustment model based on the rectangular coordinate, it suffers the problem of being seriously dependent on the initial values, making it unable to converge fast or converge to a stable state. On the contrary, APCP method could deal with quite complex condition of UAS when conducting monitoring as it represent the points in space with angles, including the condition that the sequential images focusing on one object have zero parallax angle. In brief, this paper presents the parameterization of 3D feature points based on APCP, and derives a full bundle adjustment model and the corresponding nonlinear optimization problems based on this method. In addition, we analyze the influence of convergence and dependence on the initial values through math formulas. At last this paper conducts experiments using real aviation data, and proves that the new model can effectively solve bottlenecks of the classical method in a certain degree, that is, this paper provides a new idea and solution for faster and more efficient environmental monitoring.

Identifying unusual performance in Australian and New Zealand intensive care units from 2000 to 2010

PubMed Central

2014-01-01

Background The Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database (APD) collects voluntary data on patient admissions to Australian and New Zealand intensive care units (ICUs). This paper presents an in-depth statistical analysis of risk-adjusted mortality of ICU admissions from 2000 to 2010 for the purpose of identifying ICUs with unusual performance. Methods A cohort of 523,462 patients from 144 ICUs was analysed. For each ICU, the natural logarithm of the standardised mortality ratio (log-SMR) was estimated from a risk-adjusted, three-level hierarchical model. This is the first time a three-level model has been fitted to such a large ICU database anywhere. The analysis was conducted in three stages which included the estimation of a null distribution to describe usual ICU performance. Log-SMRs with appropriate estimates of standard errors are presented in a funnel plot using 5% false discovery rate thresholds. False coverage-statement rate confidence intervals are also presented. The observed numbers of deaths for ICUs identified as unusual are compared to the predicted true worst numbers of deaths under the model for usual ICU performance. Results Seven ICUs were identified as performing unusually over the period 2000 to 2010, in particular, demonstrating high risk-adjusted mortality compared to the majority of ICUs. Four of the seven were ICUs in private hospitals. Our three-stage approach to the analysis detected outlying ICUs which were not identified in a conventional (single) risk-adjusted model for mortality using SMRs to compare ICUs. We also observed a significant linear decline in mortality over the decade. Distinct yearly and weekly respiratory seasonal effects were observed across regions of Australia and New Zealand for the first time. Conclusions The statistical approach proposed in this paper is intended to be used for the review of observed ICU and hospital mortality. Two important messages from our study are firstly, that comprehensive risk-adjustment is essential in modelling patient mortality for comparing performance, and secondly, that the appropriate statistical analysis is complicated. PMID:24755369

Coffee or Tea, Hot or Cold, Are Not Associated With Risk of Barrett's Esophagus.

PubMed

Sajja, Krishna C; El-Serag, Hashem B; Thrift, Aaron P

2016-05-01

Epidemiologic data regarding coffee and tea consumption and risk of esophageal inflammation, Barrett's esophagus (BE), and adenocarcinoma are sparse and inconclusive. This study examined the association between consumption of tea or coffee with risk of BE. We conducted a cross-sectional study among US veterans, comparing 310 patients with histologically confirmed BE with 1728 individuals with no endoscopic or histopathologic features of BE (controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models. In univariate models, we found a statistically significant association between risk of BE and consumption of coffee (OR, 1.41; 95% CI, 1.06-1.87) or tea (OR, 1.34; 95% CI, 1.05-1.71). However, in multivariate analysis, in which models were adjusted for confounders including sex and race, we found no association between risk of BE and consumption of coffee (adjusted OR, 1.04; 95% CI, 0.76-1.42) or tea (adjusted OR, 1.11; 95% CI, 0.85-1.44). These data do not support an association between consumption of coffee or tea and the risk of BE. It is unlikely that avoidance of coffee or tea will protect against BE. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Combined expectancies: electrophysiological evidence for the adjustment of expectancy effects

PubMed Central

Mattler, Uwe; van der Lugt, Arie; Münte, Thomas F

2006-01-01

Background When subjects use cues to prepare for a likely stimulus or a likely response, reaction times are facilitated by valid cues but prolonged by invalid cues. In studies on combined expectancy effects, two cues can independently give information regarding two dimensions of the forthcoming task. In certain situations, cueing effects on one dimension are reduced when the cue on the other dimension is invalid. According to the Adjusted Expectancy Model, cues affect different processing levels and a mechanism is presumed which is sensitive to the validity of early level cues and leads to online adjustment of expectancy effects at later levels. To examine the predictions of this model cueing of stimulus modality was combined with response cueing. Results Behavioral measures showed the interaction of cueing effects. Electrophysiological measures of the lateralized readiness potential (LRP) and the N200 amplitude confirmed the predictions of the model. The LRP showed larger effects of response cues on response activation when modality cues were valid rather than invalid. N200 amplitude was largest with valid modality cues and invalid response cues, medium with invalid modality cues, and smallest with two valid cues. Conclusion Findings support the view that the validity of early level expectancies modulates the effects of late level expectancies, which included response activation and response conflict in the present study. PMID:16674805

Diagnosis-Based Risk Adjustment for Medicare Capitation Payments

PubMed Central

Ellis, Randall P.; Pope, Gregory C.; Iezzoni, Lisa I.; Ayanian, John Z.; Bates, David W.; Burstin, Helen; Ash, Arlene S.

1996-01-01

Using 1991-92 data for a 5-percent Medicare sample, we develop, estimate, and evaluate risk-adjustment models that utilize diagnostic information from both inpatient and ambulatory claims to adjust payments for aged and disabled Medicare enrollees. Hierarchical coexisting conditions (HCC) models achieve greater explanatory power than diagnostic cost group (DCG) models by taking account of multiple coexisting medical conditions. Prospective models predict average costs of individuals with chronic conditions nearly as well as concurrent models. All models predict medical costs far more accurately than the current health maintenance organization (HMO) payment formula. PMID:10172666

Decision-analytic modeling studies: An overview for clinicians using multiple myeloma as an example.

PubMed

Rochau, U; Jahn, B; Qerimi, V; Burger, E A; Kurzthaler, C; Kluibenschaedl, M; Willenbacher, E; Gastl, G; Willenbacher, W; Siebert, U

2015-05-01

The purpose of this study was to provide a clinician-friendly overview of decision-analytic models evaluating different treatment strategies for multiple myeloma (MM). We performed a systematic literature search to identify studies evaluating MM treatment strategies using mathematical decision-analytic models. We included studies that were published as full-text articles in English, and assessed relevant clinical endpoints, and summarized methodological characteristics (e.g., modeling approaches, simulation techniques, health outcomes, perspectives). Eleven decision-analytic modeling studies met our inclusion criteria. Five different modeling approaches were adopted: decision-tree modeling, Markov state-transition modeling, discrete event simulation, partitioned-survival analysis and area-under-the-curve modeling. Health outcomes included survival, number-needed-to-treat, life expectancy, and quality-adjusted life years. Evaluated treatment strategies included novel agent-based combination therapies, stem cell transplantation and supportive measures. Overall, our review provides a comprehensive summary of modeling studies assessing treatment of MM and highlights decision-analytic modeling as an important tool for health policy decision making. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The "Nursing Home Compare" measure of urinary/fecal incontinence: cross-sectional variation, stability over time, and the impact of case mix.

PubMed

Li, Yue; Schnelle, John; Spector, William D; Glance, Laurent G; Mukamel, Dana B

2010-02-01

To assess the impact of facility case mix on cross-sectional variations and short-term stability of the "Nursing Home Compare" incontinence quality measure (QM) and to determine whether multivariate risk adjustment can minimize such impacts. Retrospective analyses of the 2005 national minimum data set (MDS) that included approximately 600,000 long-term care residents in over 10,000 facilities in each quarterly sample. Mixed logistic regression was used to construct the risk-adjusted QM (nonshrinkage estimator). Facility-level ordinary least-squares models and adjusted R(2) were used to estimate the impact of case mix on cross-sectional and short-term longitudinal variations of currently published and risk-adjusted QMs. At least 50 percent of the cross-sectional variation and 25 percent of the short-term longitudinal variation of the published QM are explained by facility case mix. In contrast, the cross-sectional and short-term longitudinal variations of the risk-adjusted QM are much less susceptible to case-mix variations (adjusted R(2)<0.10), even for facilities with more extreme or more unstable outcome. Current "Nursing Home Compare" incontinence QM reflects considerable case-mix variations across facilities and over time, and therefore it may be biased. This issue can be largely addressed by multivariate risk adjustment using risk factors available in the MDS.

Calibrating the orientation between a microlens array and a sensor based on projective geometry

NASA Astrophysics Data System (ADS)

Su, Lijuan; Yan, Qiangqiang; Cao, Jun; Yuan, Yan

2016-07-01

We demonstrate a method for calibrating a microlens array (MLA) with a sensor component by building a plenoptic camera with a conventional prime lens. This calibration method includes a geometric model, a setup to adjust the distance (L) between the prime lens and the MLA, a calibration procedure for determining the subimage centers, and an optimization algorithm. The geometric model introduces nine unknown parameters regarding the centers of the microlenses and their images, whereas the distance adjustment setup provides an initial guess for the distance L. The simulation results verify the effectiveness and accuracy of the proposed method. The experimental results demonstrate the calibration process can be performed with a commercial prime lens and the proposed method can be used to quantitatively evaluate whether a MLA and a sensor is assembled properly for plenoptic systems.

Model Performance Evaluation and Scenario Analysis ...

EPA Pesticide Factsheets

This tool consists of two parts: model performance evaluation and scenario analysis (MPESA). The model performance evaluation consists of two components: model performance evaluation metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit measures that capture magnitude only, sequence only, and combined magnitude and sequence errors. The performance measures include error analysis, coefficient of determination, Nash-Sutcliffe efficiency, and a new weighted rank method. These performance metrics only provide useful information about the overall model performance. Note that MPESA is based on the separation of observed and simulated time series into magnitude and sequence components. The separation of time series into magnitude and sequence components and the reconstruction back to time series provides diagnostic insights to modelers. For example, traditional approaches lack the capability to identify if the source of uncertainty in the simulated data is due to the quality of the input data or the way the analyst adjusted the model parameters. This report presents a suite of model diagnostics that identify if mismatches between observed and simulated data result from magnitude or sequence related errors. MPESA offers graphical and statistical options that allow HSPF users to compare observed and simulated time series and identify the parameter values to adjust or the input data to modify. The scenario analysis part of the too

Parenting Styles and Adolescents’ School Adjustment: Investigating the Mediating Role of Achievement Goals within the 2 × 2 Framework

PubMed Central

Xiang, Shiyuan; Liu, Yan; Bai, Lu

2017-01-01

This study examines the multiple mediating roles of achievement goals based on a 2 × 2 framework of the relationships between parenting styles and adolescents’ school adjustment. The study sample included 1061 Chinese adolescent students (50.4% girls) between the ages of 12 and 19, who completed questionnaires regarding parenting styles (parental autonomy support and psychological control), achievement goals (mastery approach, mastery avoidance, performance approach, and performance avoidance goals) and school adjustment variables (emotion, students’ life satisfaction, school self-esteem, problem behavior, academic achievement, and self-determination in school). A structural equation modeling (SEM) approach was used to test our hypotheses. The results indicated that parental autonomy support was associated with adolescents’ school adjustment in an adaptive manner, both directly and through its positive relationship with both mastery and performance approach goals; however, parental psychological control was associated with adolescents’ school adjustment in a maladaptive manner, both directly and through its positive relationship with both mastery and performance avoidance goals. In addition, the results indicated that mastery avoidance goals suppressed the relationship between parental autonomy support and adolescents’ school adjustment, and performance approach goals suppressed the relationship between this adjustment and parental psychological control. These findings extend the limited literature regarding the 2 × 2 framework of achievement goals and enable us to evidence the mediating and suppressing effects of achievement goals. This study highlights the importance of parenting in adolescents’ school adjustment through the cultivation of different achievement goals. PMID:29085321

Parenting Styles and Adolescents' School Adjustment: Investigating the Mediating Role of Achievement Goals within the 2 × 2 Framework.

PubMed

Xiang, Shiyuan; Liu, Yan; Bai, Lu

2017-01-01

This study examines the multiple mediating roles of achievement goals based on a 2 × 2 framework of the relationships between parenting styles and adolescents' school adjustment. The study sample included 1061 Chinese adolescent students (50.4% girls) between the ages of 12 and 19, who completed questionnaires regarding parenting styles (parental autonomy support and psychological control), achievement goals (mastery approach, mastery avoidance, performance approach, and performance avoidance goals) and school adjustment variables (emotion, students' life satisfaction, school self-esteem, problem behavior, academic achievement, and self-determination in school). A structural equation modeling (SEM) approach was used to test our hypotheses. The results indicated that parental autonomy support was associated with adolescents' school adjustment in an adaptive manner, both directly and through its positive relationship with both mastery and performance approach goals; however, parental psychological control was associated with adolescents' school adjustment in a maladaptive manner, both directly and through its positive relationship with both mastery and performance avoidance goals. In addition, the results indicated that mastery avoidance goals suppressed the relationship between parental autonomy support and adolescents' school adjustment, and performance approach goals suppressed the relationship between this adjustment and parental psychological control. These findings extend the limited literature regarding the 2 × 2 framework of achievement goals and enable us to evidence the mediating and suppressing effects of achievement goals. This study highlights the importance of parenting in adolescents' school adjustment through the cultivation of different achievement goals.

76 FR 53424 - Intent To Prepare a Draft Supplemental Environmental Impact Statement for the Larose to Golden...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

... post-Katrina Hurricane and Storm Damage Risk Reduction System (HSDRRS) Design Guidelines, are in...-Hurricane Katrina hydrology and hydraulics design guidelines; (2) modify the 1965 design to complete the... adjustments) using the current HSDRRS Design Guidelines to include the Post-Hurricane Katrina surge models; (3...

Cost-Effectiveness of Evaluating the New Technologies.

ERIC Educational Resources Information Center

Kastner, Theodore A.

1997-01-01

This commentary on a study comparing use of the brand name drug Depakene with generic valproic acid to control seizures in people with mental retardation focuses on issues of cost-effectiveness. It notes existing guidelines for pharmacoeconomic evaluation and suggests a possible model to include a threshold price (per quality-adjusted life year)…

Bullying and Smoking: Examining the Relationships in Ontario Adolescents

ERIC Educational Resources Information Center

Morris, Erin B.; Zhang, Bo; Bondy, Susan J.

2006-01-01

Using data from the 2003 Ontario Student Drug Use Survey (Centre for Addiction and Mental Health, Toronto), the relationships between bullying and smoking in adolescents were examined. A representative sample of 3314 grade 7-12 students was included in the analysis. Models were adjusted for confounders identified in the current literature.…

"Children of Great Development": Difficulties in the Education and Development of Rural Left-Behind Children

ERIC Educational Resources Information Center

Pan, Lu; Ye, Jingzhong

2017-01-01

Over the past 30 years in China, the development ideology--a model of economic development that is characterized by urbanization, industrialization, and modernization--has brought about many changes and consequences, including increased migration by the rural population, sharp adjustments in urban-rural education policy, the decline of rural…

The Experience of Risk-Adjusted Capitation Payment for Family Physicians in Iran: A Qualitative Study.

PubMed

Esmaeili, Reza; Hadian, Mohammad; Rashidian, Arash; Shariati, Mohammad; Ghaderi, Hossien

2016-04-01

When a country's health system is faced with fundamental flaws that require the redesign of financing and service delivery, primary healthcare payment systems are often reformed. This study was conducted with the purpose of exploring the experiences of risk-adjusted capitation payment of urban family physicians in Iran when it comes to providing primary health care (PHC). This is a qualitative study using the framework method. Data were collected via digitally audio-recorded semi-structured interviews with 24 family physicians and 5 executive directors in two provinces of Iran running the urban family physician pilot program. The participants were selected using purposive and snowball sampling. The codes were extracted using inductive and deductive methods. Regarding the effects of risk-adjusted capitation on the primary healthcare setting, five themes with 11 subthemes emerged, including service delivery, institutional structure, financing, people's behavior, and the challenges ahead. Our findings indicated that the health system is enjoying some major changes in the primary healthcare setting through the implementation of risk-adjusted capitation payment. With regard to the current challenges in Iran's health system, using risk-adjusted capitation as a primary healthcare payment system can lead to useful changes in the health system's features. However, future research should focus on the development of the risk-adjusted capitation model.

Monitoring risk-adjusted medical outcomes allowing for changes over time.

PubMed

Steiner, Stefan H; Mackay, R Jock

2014-10-01

We consider the problem of monitoring and comparing medical outcomes, such as surgical performance, over time. Performance is subject to change due to a variety of reasons including patient heterogeneity, learning, deteriorating skills due to aging, etc. For instance, we expect inexperienced surgeons to improve their skills with practice. We propose a graphical method to monitor surgical performance that incorporates risk adjustment to account for patient heterogeneity. The procedure gives more weight to recent outcomes and down-weights the influence of outcomes further in the past. The chart is clinically interpretable as it plots an estimate of the failure rate for a "standard" patient. The chart also includes a measure of uncertainty in this estimate. We can implement the method using historical data or start from scratch. As the monitoring proceeds, we can base the estimated failure rate on a known risk model or use the observed outcomes to update the risk model as time passes. We illustrate the proposed method with an example from cardiac surgery. © The Author 2013. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Influence of sex and CYP2D6 genotype on mirtazapine disposition, evaluated in Spanish healthy volunteers.

PubMed

Borobia, Alberto M; Novalbos, Jesús; Guerra-López, Pedro; López-Rodríguez, Rosario; Tabares, Beatriz; Rodríguez, Vanesa; Abad-Santos, Francisco; Carcas, Antonio J

2009-06-01

To evaluate the influence of sex and CYP2D6 genotype on mirtazapine disposition within two bioequivalence studies in healthy volunteers. Seventy-two healthy volunteers were included in two standard 2 x 2 crossover bioequivalence trials. Subjects received a single 30-mg oral dose of each mirtazapine formulation in each study period. Plasma concentrations were measured from 0 to 96 or 120 h by a HPLC with coupled mass spectrometry validated method. CYP2D6 genotyping was available for 68 subjects that were classified into three phenotypic groups depending on the number of active gene copies: extensive/ultrarapid metabolizers (UM-EM), intermediate (IM) and poor metabolizers (PM). To evaluate the influence of sex and genotype on mirtazapine disposition we performed a linear mixed model for repeated measures. Pharmacokinetic data were log-transformed and AUC and C(max) adjusted to the administered dose/weight. Factors included in the model were centre, formulation, period, sequence, sex and genotype as fixed effects, and subject nested sequence x sex x genotype as random one. A second model was also performed adding the interaction sex x genotype to the previous model. Mirtazapine disposition evaluated as AUC(0-infinity) is influenced by sex (p=0.007) and CYP2D6 phenotype group (p=0.01). Attending to the theoretical figures provided by the model, mean (95% CI) dose/weight adjusted AUC(0-infinity) (ng h/ml)/(mg/kg) is 1516.62 (1411.27-1628.22) in EM/UM, 1613.63 (1482.14-1758.55) in IM and 2049.28 (1779.78-2357.24) in PM. In the case of C(max) these figures also show a trend to higher values in PM, but it did not reach statistical significance. Females show a lower dose/weight adjusted AUC(0-infinity): 1594.39 (1477.70-1720.28) vs. 1837.65 (1694.67-1992.70). On the contrary dose/weight adjusted C(max) is higher in females than in males: 38.33 (34.79-42.28) vs. 32.66 (29.44-36.21). Both CYP2D6 genotype group and sex influence the disposition of mirtazapine in healthy volunteers and confirm reported data in the literature obtained by different methods. No sex-by-genotype interaction could be detected.

Sugar-sweetened beverage intake and cardiovascular risk factor profile in youth with type 1 diabetes: application of measurement error methodology in the SEARCH Nutrition Ancillary Study.

PubMed

Liese, Angela D; Crandell, Jamie L; Tooze, Janet A; Kipnis, Victor; Bell, Ronny; Couch, Sarah C; Dabelea, Dana; Crume, Tessa L; Mayer-Davis, Elizabeth J

2015-08-14

The SEARCH Nutrition Ancillary Study aims to investigate the role of dietary intake on the development of long-term complications of type 1 diabetes in youth, and capitalise on measurement error (ME) adjustment methodology. Using the National Cancer Institute (NCI) method for episodically consumed foods, we evaluated the relationship between sugar-sweetened beverage (SSB) intake and cardiovascular risk factor profile, with the application of ME adjustment methodology. The calibration sample included 166 youth with two FFQ and three 24 h dietary recall data within 1 month. The full sample included 2286 youth with type 1 diabetes. SSB intake was significantly associated with higher TAG, total and LDL-cholesterol concentrations, after adjusting for energy, age, diabetes duration, race/ethnicity, sex and education. The estimated effect size was larger (model coefficients increased approximately 3-fold) after the application of the NCI method than without adjustment for ME. Compared with individuals consuming one serving of SSB every 2 weeks, those who consumed one serving of SSB every 2 d had 3.7 mg/dl (0.04 mmol/l) higher TAG concentrations and 4.0 mg/dl (0.10 mmol/l) higher total cholesterol and LDL-cholesterol concentrations, after adjusting for ME and covariates. SSB intake was not associated with measures of adiposity and blood pressure. Our findings suggest that SSB intake is significantly related to increased lipid levels in youth with type 1 diabetes, and that estimates of the effect size of SSB on lipid levels are severely attenuated in the presence of ME. Future studies in youth with diabetes should consider a design that will allow for the adjustment for ME when studying the influence of diet on health status.

Donor characteristics and risk of hepatocellular carcinoma recurrence after liver transplantation.

PubMed

Orci, L A; Berney, T; Majno, P E; Lacotte, S; Oldani, G; Morel, P; Mentha, G; Toso, C

2015-09-01

To date, studies assessing the risk of post-transplant hepatocellular carcinoma (HCC) recurrence have focused on tumour characteristics. This study investigated the impact of donor characteristics and graft quality on post-transplant HCC recurrence. Using the Scientific Registry of Transplant Recipients patients with HCC who received a liver transplant between 2004 and 2011 were included, and post-transplant HCC recurrence was assessed. A multivariable competing risk regression model was fitted, adjusting for confounders such as recipient sex, age, tumour volume, α-fetoprotein, time on the waiting list and transplant centre. A total of 9724 liver transplant recipients were included. Patients receiving a graft procured from a donor older than 60 years (adjusted hazard ratio (HR) 1.38, 95 per cent c.i. 1.10 to 1.73; P = 0.006), a donor with a history of diabetes (adjusted HR 1.43, 1.11 to 1.83; P = 0.006) and a donor with a body mass index of 35 kg/m(2) or more (adjusted HR 1.36, 1.04 to 1.77; P = 0.023) had an increased rate of post-transplant HCC recurrence. In 3007 patients with documented steatosis, severe graft steatosis (more than 60 per cent) was also linked to an increased risk of recurrence (adjusted HR 1.65, 1.03 to 2.64; P = 0.037). Recipients of organs from donation after cardiac death donors with prolonged warm ischaemia had higher recurrence rates (adjusted HR 4.26, 1.20 to 15.1; P = 0.025). Donor-related factors such as donor age, body mass index, diabetes and steatosis are associated with an increased rate of HCC recurrence after liver transplantation. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

Factoring socioeconomic status into cardiac performance profiling for hospitals: does it matter?

PubMed

Alter, David A; Austin, Peter C; Naylor, C David; Tu, Jack V

2002-01-01

Critics of "scorecard medicine" often highlight the incompleteness of risk-adjustment methods used when accounting for baseline patient differences. Although socioeconomic status is a highly important determinant of adverse outcome for patients admitted to the hospital with acute myocardial infarction, it has not been used in most risk-adjustment models for cardiovascular report cards. To determine the incremental impact of socioeconomic status adjustments on age, sex, and illness severity for hospital-specific 30-day mortality rates after acute myocardial infarction. The authors compared the absolute and relative hospital-specific 30-day acute myocardial infarction mortality rates in 169 hospitals throughout Ontario between April 1, 1994 and March 31, 1997. Patient socioeconomic status was characterized by median neighborhood income using postal codes and 1996 Canadian census data. They examined two risk-adjustment models: the first adjusted for age, sex, and illness severity (standard), whereas the second adjusted for age, sex, illness severity, and median neighborhood income level (socioeconomic status). There was an extremely strong correlation between 'standard' and 'socioeconomic status' risk-adjusted mortality rates (r = 0.99). Absolute differences in 30-day risk-adjusted mortality rates between the socioeconomic status and standard risk-adjustment models were small (median, 0.1%; 25th-75th percentile, 0.1-0.2). The agreement in the quintile rankings of hospitals between the socioeconomic status and standard risk-adjustment models was high (weighted kappa = 0.93). Despite its importance as a determinant of patient outcomes, the effect of socioeconomic status on hospital-specific mortality rates over and above standard risk-adjustment methods for acute myocardial infarction hospital profiling in Ontario was negligible.

Custodial grandmothers' psychological distress, dysfunctional parenting, and grandchildren's adjustment.

PubMed

Smith, Gregory C; Palmieri, Patrick A; Hancock, Gregory R; Richardson, Rhonda A

2008-01-01

An adaptation of the Family Stress Model (FSM) with hypothesized linkages between family contextual factors, custodial grandmothers' psychological distress, parenting practices, and grandchildren's adjustment was tested with structural equation modeling. Interview data from 733 custodial grandmothers of grandchildren between ages 4-17 revealed that the effect of grandmothers' distress on grandchildren's adjustment was mediated by dysfunctional parenting, especially regarding externalizing problems. The effects of contextual factors on grandchildren's adjustment were also indirect. The model's measurement and structural components were largely invariant across grandmothers' race and age, as well as grandchildren's gender and age. Group differences were more prevalent regarding the magnitude of latent means for model constructs. We conclude that parenting models like the FSM are useful for investigating custodial grandfamilies.

Custodial Grandmothers' Psychological Distress, Dysfunctional Parenting, and Grandchildren's Adjustment*ł

PubMed Central

Smith, Gregory C.; Palmieri, Patrick A.; Hancock, Gregory R.; Richardson, Rhonda A.

2009-01-01

An adaptation of the Family Stress Model (FSM) with hypothesized linkages between family contextual factors, custodial grandmothers' psychological distress, parenting practices, and grandchildren's adjustment was tested with structural equation modeling. Interview data from 733 custodial grandmothers of grandchildren between ages 4-17 revealed that the effect of grandmothers' distress on grandchildren's adjustment was mediated by dysfunctional parenting, especially regarding externalizing problems. The effects of contextual factors on grandchildren's adjustment were also indirect. The model's measurement and structural components were largely invariant across grandmothers' race and age, as well as grandchildren's gender and age. Group differences were more prevalent regarding the magnitude of latent means for model constructs. We conclude that parenting models like the FSM are useful for investigating custodial grandfamilies. PMID:19266869

Contact angle adjustment in equation-of-state-based pseudopotential model.

PubMed

Hu, Anjie; Li, Longjian; Uddin, Rizwan; Liu, Dong

2016-05-01

The single component pseudopotential lattice Boltzmann model has been widely applied in multiphase simulation due to its simplicity and stability. In many studies, it has been claimed that this model can be stable for density ratios larger than 1000. However, the application of the model is still limited to small density ratios when the contact angle is considered. The reason is that the original contact angle adjustment method influences the stability of the model. Moreover, simulation results in the present work show that, by applying the original contact angle adjustment method, the density distribution near the wall is artificially changed, and the contact angle is dependent on the surface tension. Hence, it is very inconvenient to apply this method with a fixed contact angle, and the accuracy of the model cannot be guaranteed. To solve these problems, a contact angle adjustment method based on the geometry analysis is proposed and numerically compared with the original method. Simulation results show that, with our contact angle adjustment method, the stability of the model is highly improved when the density ratio is relatively large, and it is independent of the surface tension.

Contact angle adjustment in equation-of-state-based pseudopotential model

NASA Astrophysics Data System (ADS)

Hu, Anjie; Li, Longjian; Uddin, Rizwan; Liu, Dong

2016-05-01

The single component pseudopotential lattice Boltzmann model has been widely applied in multiphase simulation due to its simplicity and stability. In many studies, it has been claimed that this model can be stable for density ratios larger than 1000. However, the application of the model is still limited to small density ratios when the contact angle is considered. The reason is that the original contact angle adjustment method influences the stability of the model. Moreover, simulation results in the present work show that, by applying the original contact angle adjustment method, the density distribution near the wall is artificially changed, and the contact angle is dependent on the surface tension. Hence, it is very inconvenient to apply this method with a fixed contact angle, and the accuracy of the model cannot be guaranteed. To solve these problems, a contact angle adjustment method based on the geometry analysis is proposed and numerically compared with the original method. Simulation results show that, with our contact angle adjustment method, the stability of the model is highly improved when the density ratio is relatively large, and it is independent of the surface tension.

Identification of posttraumatic growth trajectories in the first year after breast cancer surgery.

PubMed

Wang, Ashley Wei-Ting; Chang, Cheng-Shyong; Chen, Shou-Tung; Chen, Dar-Ren; Hsu, Wen-Yau

2014-12-01

Empirical studies of the relationship between posttraumatic growth (PTG) and adjustment outcomes reveal a fairly inconclusive picture. We argue that the inconsistent findings are likely due to the heterogeneity of the PTG experience over time. In this regard, we predicted that individuals with different PTG trajectories vary in the level of adjustment and the correlational patterns between PTG and adjustment. Participants were 124 Taiwanese women who underwent surgery for breast cancer. Measures of PTG and adjustment variables, including positive affect, negative affect, mental and physical quality of life, anxiety, and depression, were assessed at 1 day and 3, 6, and 12 months after surgery. A group-based trajectory model was used to identify subpopulations of individuals who shared homogenous growth patterns. Then, we determined whether the trajectory predicted adjustment at 12 months after surgery. The correlations between PTG and adjustment outcomes were computed in each subpopulation across every time point. The patients were categorized into the following four groups, which showed very different patterns of PTG change over the first year after breast cancer surgery: stable high (27.4%), high decreasing (39.4%), low increasing (16.9%), and low decreasing (16.9%). Differences in the level of adjustment at 12 months and the patterns of the correlations across time were found among these latent subgroups This study was the first longitudinal examination of PTG trajectories and their different levels of adjustment. The findings support our argument that identifying distinct PTG trajectories can better determine the nature of the relationship between PTG and adjustment. Copyright © 2014 John Wiley & Sons, Ltd.

Sirolimus and tacrolimus trough concentrations and dose requirements after kidney transplantation in relation to CYP3A5 and MDR1 polymorphisms and steroids.

PubMed

Mourad, Michel; Mourad, Georges; Wallemacq, Pierre; Garrigue, Valérie; Van Bellingen, Christophe; Van Kerckhove, Valérie; De Meyer, Martine; Malaise, Jacques; Eddour, Djamila Chaib; Lison, Dominique; Squifflet, Jean Paul; Haufroid, Vincent

2005-10-15

CYP3A5 and MDR1 polymorphisms have been shown to influence tacrolimus blood concentrations and dose requirements. The aim is to determine whether these polymorphisms also affect sirolimus trough concentrations and dose requirements after kidney transplantation. Eighty-five renal transplant recipients receiving sirolimus were included. Twenty-four were treated with a combined sirolimus-tacrolimus regimen. Eighty-one patients received steroids. Sirolimus and tacrolimus were adjusted to a target therapeutic window. CYP3A5 (intron 3) and MDR1 (exons 12, 21, 26) genotypes were correlated to the adjusted trough concentrations and dose requirements for both sirolimus and tacrolimus. There were no significant correlation between adjusted sirolimus trough concentrations or dose requirements and genetic polymorphisms. In a multiple regression model, adjusted-prednisone dose was involved with a positive or negative effect when considering sirolimus dose requirements or adjusted concentrations, respectively. In the subgroup of patients treated by tacrolimus and sirolimus, adjusted tacrolimus doses were higher in patients carrying at least one CYP3A5 *1 allele (median 0.083 vs. 0.035 mg/kg for CYP3A5*3/*3 patients, P<0.05). Adjusted-prednisolone dose and CYP3A5 polymorphism explained up to 61% of the variability in tacrolimus dose requirements. Unlike tacrolimus, sirolimus adjusted trough concentrations and dose requirements seem not affected by CYP3A5 and MDR1 polymorphisms. Adjusted-prednisone dose has a significant impact on tacrolimus and sirolimus dose requirements.

Trajectories of premorbid childhood and adolescent functioning in schizophrenia-spectrum psychoses: A first-episode study.

PubMed

Horton, Leslie E; Tarbox, Sarah I; Olino, Thomas M; Haas, Gretchen L

2015-06-30

Evidence of social and behavioral problems preceding the onset of schizophrenia-spectrum psychoses is consistent with a neurodevelopmental model of these disorders. Here we predict that individuals with a first episode of schizophrenia-spectrum psychoses will evidence one of three patterns of premorbid adjustment: an early deficit, a deteriorating pattern, or adequate or good social adjustment. Participants were 164 (38% female; 31% black) individuals ages 15-50 with a first episode of schizophrenia-spectrum psychoses. Premorbid adjustment was assessed using the Cannon-Spoor Premorbid Adjustment Scale. We compared the fit of a series of growth mixture models to examine premorbid adjustment trajectories, and found the following 3-class model provided the best fit with: a "stable-poor" adjustment class (54%), a "stable-good" adjustment class (39%), and a "deteriorating" adjustment class (7%). Relative to the "stable-good" class, the "stable-poor" class experienced worse negative symptoms at 1-year follow-up, particularly in the social amotivation domain. This represents the first known growth mixture modeling study to examine premorbid functioning patterns in first-episode schizophrenia-spectrum psychoses. Given that the stable-poor adjustment pattern was most prevalent, detection of social and academic maladjustment as early as childhood may help identify people at increased risk for schizophrenia-spectrum psychoses, potentially increasing feasibility of early interventions. Published by Elsevier Ireland Ltd.

NKG201xGIA - first results for a new model of glacial isostatic adjustment in Fennoscandia

NASA Astrophysics Data System (ADS)

Steffen, Holger; Barletta, Valentina; Kollo, Karin; Milne, Glenn A.; Nordman, Maaria; Olsson, Per-Anders; Simpson, Matthew J. R.; Tarasov, Lev; Ågren, Jonas

2016-04-01

Glacial isostatic adjustment (GIA) is a dominant process in northern Europe, which is observed with several geodetic and geophysical methods. The observed land uplift due to this process amounts to about 1 cm/year in the northern Gulf of Bothnia. GIA affects the establishment and maintenance of reliable geodetic and gravimetric reference networks in the Nordic countries. To support a high level of accuracy in the determination of position, adequate corrections have to be applied with dedicated models. Currently, there are efforts within a Nordic Geodetic Commission (NKG) activity towards a model of glacial isostatic adjustment for Fennoscandia. The new model, NKG201xGIA, to be developed in the near future will complement the forthcoming empirical NKG land uplift model, which will substitute the currently used empirical land uplift model NKG2005LU (Ågren & Svensson, 2007). Together, the models will be a reference for vertical and horizontal motion, gravity and geoid change and more. NKG201xGIA will also provide uncertainty estimates for each field. Following former investigations, the GIA model is based on a combination of an ice and an earth model. The selected reference ice model, GLAC, for Fennoscandia, the Barents/Kara seas and the British Isles is provided by Lev Tarasov and co-workers. Tests of different ice and earth models will be performed based on the expertise of each involved modeler. This includes studies on high resolution ice sheets, different rheologies, lateral variations in lithosphere and mantle viscosity and more. This will also be done in co-operation with scientists outside NKG who help in the development and testing of the model. References Ågren, J., Svensson, R. (2007): Postglacial Land Uplift Model and System Definition for the New Swedish Height System RH 2000. Reports in Geodesy and Geographical Information Systems Rapportserie, LMV-Rapport 4, Lantmäteriet, Gävle.

Contemporary group estimates adjusted for climatic effects provide a finer definition of the unknown environmental challenges experienced by growing pigs.

PubMed

Guy, S Z Y; Li, L; Thomson, P C; Hermesch, S

2017-12-01

Environmental descriptors derived from mean performances of contemporary groups (CGs) are assumed to capture any known and unknown environmental challenges. The objective of this paper was to obtain a finer definition of the unknown challenges, by adjusting CG estimates for the known climatic effects of monthly maximum air temperature (MaxT), minimum air temperature (MinT) and monthly rainfall (Rain). As the unknown component could include infection challenges, these refined descriptors may help to better model varying responses of sire progeny to environmental infection challenges for the definition of disease resilience. Data were recorded from 1999 to 2013 at a piggery in south-east Queensland, Australia (n = 31,230). Firstly, CG estimates of average daily gain (ADG) and backfat (BF) were adjusted for MaxT, MinT and Rain, which were fitted as splines. In the models used to derive CG estimates for ADG, MaxT and MinT were significant variables. The models that contained these significant climatic variables had CG estimates with a lower variance compared to models without significant climatic variables. Variance component estimates were similar across all models, suggesting that these significant climatic variables accounted for some known environmental variation captured in CG estimates. No climatic variables were significant in the models used to derive the CG estimates for BF. These CG estimates were used to categorize environments. There was no observable sire by environment interaction (Sire×E) for ADG when using the environmental descriptors based on CG estimates on BF. For the environmental descriptors based on CG estimates of ADG, there was significant Sire×E only when MinT was included in the model (p = .01). Therefore, this new definition of the environment, preadjusted by MinT, increased the ability to detect Sire×E. While the unknown challenges captured in refined CG estimates need verification for infection challenges, this may provide a practical approach for the genetic improvement of disease resilience. © 2017 Blackwell Verlag GmbH.

Modeling longitudinal data, I: principles of multivariate analysis.

PubMed

Ravani, Pietro; Barrett, Brendan; Parfrey, Patrick

2009-01-01

Statistical models are used to study the relationship between exposure and disease while accounting for the potential role of other factors' impact on outcomes. This adjustment is useful to obtain unbiased estimates of true effects or to predict future outcomes. Statistical models include a systematic component and an error component. The systematic component explains the variability of the response variable as a function of the predictors and is summarized in the effect estimates (model coefficients). The error element of the model represents the variability in the data unexplained by the model and is used to build measures of precision around the point estimates (confidence intervals).

Peer Victimization and Rejection: Investigation of an Integrative Model of Effects on Emotional, Behavioral, and Academic Adjustment in Early Adolescence

ERIC Educational Resources Information Center

Lopez, Cristy; DuBois, David L.

2005-01-01

This study investigated an integrative model of the effects of peer victimization (PV) and peer rejection (PR) on youth adjustment using data from 508 middle-school students. In the proposed model, PV and PR each contribute independently to problems in emotional, behavioral, and academic adjustment. The adverse consequences of PV and PR are each…

Adjusting for overdispersion in piecewise exponential regression models to estimate excess mortality rate in population-based research.

PubMed

Luque-Fernandez, Miguel Angel; Belot, Aurélien; Quaresma, Manuela; Maringe, Camille; Coleman, Michel P; Rachet, Bernard

2016-10-01

In population-based cancer research, piecewise exponential regression models are used to derive adjusted estimates of excess mortality due to cancer using the Poisson generalized linear modelling framework. However, the assumption that the conditional mean and variance of the rate parameter given the set of covariates x i are equal is strong and may fail to account for overdispersion given the variability of the rate parameter (the variance exceeds the mean). Using an empirical example, we aimed to describe simple methods to test and correct for overdispersion. We used a regression-based score test for overdispersion under the relative survival framework and proposed different approaches to correct for overdispersion including a quasi-likelihood, robust standard errors estimation, negative binomial regression and flexible piecewise modelling. All piecewise exponential regression models showed the presence of significant inherent overdispersion (p-value <0.001). However, the flexible piecewise exponential model showed the smallest overdispersion parameter (3.2 versus 21.3) for non-flexible piecewise exponential models. We showed that there were no major differences between methods. However, using a flexible piecewise regression modelling, with either a quasi-likelihood or robust standard errors, was the best approach as it deals with both, overdispersion due to model misspecification and true or inherent overdispersion.

Development and Validation of an Agency for Healthcare Research and Quality Indicator for Mortality After Congenital Heart Surgery Harmonized With Risk Adjustment for Congenital Heart Surgery (RACHS-1) Methodology.

PubMed

Jenkins, Kathy J; Koch Kupiec, Jennifer; Owens, Pamela L; Romano, Patrick S; Geppert, Jeffrey J; Gauvreau, Kimberlee

2016-05-20

The National Quality Forum previously approved a quality indicator for mortality after congenital heart surgery developed by the Agency for Healthcare Research and Quality (AHRQ). Several parameters of the validated Risk Adjustment for Congenital Heart Surgery (RACHS-1) method were included, but others differed. As part of the National Quality Forum endorsement maintenance process, developers were asked to harmonize the 2 methodologies. Parameters that were identical between the 2 methods were retained. AHRQ's Healthcare Cost and Utilization Project State Inpatient Databases (SID) 2008 were used to select optimal parameters where differences existed, with a goal to maximize model performance and face validity. Inclusion criteria were not changed and included all discharges for patients <18 years with International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes for congenital heart surgery or nonspecific heart surgery combined with congenital heart disease diagnosis codes. The final model includes procedure risk group, age (0-28 days, 29-90 days, 91-364 days, 1-17 years), low birth weight (500-2499 g), other congenital anomalies (Clinical Classifications Software 217, except for 758.xx), multiple procedures, and transfer-in status. Among 17 945 eligible cases in the SID 2008, the c statistic for model performance was 0.82. In the SID 2013 validation data set, the c statistic was 0.82. Risk-adjusted mortality rates by center ranged from 0.9% to 4.1% (5th-95th percentile). Congenital heart surgery programs can now obtain national benchmarking reports by applying AHRQ Quality Indicator software to hospital administrative data, based on the harmonized RACHS-1 method, with high discrimination and face validity. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Estradiol and inflammatory markers in older men.

PubMed

Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Metter, E Jeffrey; Artoni, Andrea; Gatti, Elisa; Ruggiero, Carmelinda; Guralnik, Jack M; Valenti, Giorgio; Ling, Shari M; Basaria, Shehzad; Ferrucci, Luigi

2009-02-01

Aging is characterized by a mild proinflammatory state. In older men, low testosterone levels have been associated with increasing levels of proinflammatory cytokines. It is still unclear whether estradiol (E2), which generally has biological activities complementary to testosterone, affects inflammation. We analyzed data obtained from 399 men aged 65-95 yr enrolled in the Invecchiare in Chianti study with complete data on body mass index (BMI), serum E2, testosterone, IL-6, soluble IL-6 receptor, TNF-alpha, IL-1 receptor antagonist, and C-reactive protein. The relationship between E2 and inflammatory markers was examined using multivariate linear models adjusted for age, BMI, smoking, physical activity, chronic disease, and total testosterone. In age-adjusted analysis, log (E2) was positively associated with log (IL-6) (r = 0.19; P = 0.047), and the relationship was statistically significant (P = 0.032) after adjustments for age, BMI, smoking, physical activity, chronic disease, and serum testosterone levels. Log (E2) was not significantly associated with log (C-reactive protein), log (soluble IL-6 receptor), or log (TNF-alpha) in both age-adjusted and fully adjusted analyses. In older men, E2 is weakly positively associated with IL-6, independent of testosterone and other confounders including BMI.

Dual resolution, vacuum compatible optical mount

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

Halpin, John Michael

2011-10-04

An optical mount for an optical element includes a mounting plate, a lever arm pivot coupled to mounting plate, and an adjustment plate. The optical mount also includes a flexure pivot mechanically coupling the adjustment plate to the mounting plate and a lever arm. The optical mount further includes a first adjustment device extending from the adjustment plate to make contact with the lever arm at a first contact point. A projection of a line from the first contact point to a pivot point, measured along the lever arm, is a first predetermined distance. The optical mount additionally includes amore » second adjustment device extending from the adjustment plate to make contact with the lever arm at a second contact point. A projection of a line from the second contact point to the pivot point, measured along the lever arm, is a second predetermined distance greater than the first predetermined distance.« less

Exposure to traffic noise and air pollution and risk for febrile seizure: a cohort study.

PubMed

Hjortebjerg, Dorrit; Nybo Andersen, Anne-Marie; Ketzel, Matthias; Raaschou-Nielsen, Ole; Sørensen, Mette

2018-03-25

Objectives Exposure to traffic noise and air pollution is suspected to increase susceptibility to viral infections - the main triggering factor for febrile seizures. No studies have examined these two exposures in relation to febrile seizures. We aimed to investigate whether exposure to road traffic noise and air pollution are associated with risk of febrile seizures in childhood. Methods From our study base of 51 465 singletons from a national birth cohort, we identified 2175 cases with febrile seizures using a nationwide registry. Residential address history from conception to six years of age were found in national registers, and road traffic noise (L den ) and air pollution (NO 2 ) were modeled for all addresses. Analyses were done using Cox proportional hazard model with adjustment for potential confounders, including mutual exposure adjustment. Results An interquartile range (IQR) increase in childhood exposure to road traffic noise and air pollution was associated with an 11% [incidence rate ratio (IRR) 1.11, 95% confidence interval (CI) 1.04-1.19) and 5% (IRR 1.05, 95% CI 1.02-1.07) higher risk for febrile seizures, respectively, after adjustment for potential confounders. Weaker tendencies were seen for pregnancy exposure. In models with mutual exposure adjustment, the estimates were slightly lower, with IRR of 1.08 (95% CI 1.00-1.16) and 1.03 (95% CI 0.99-1.06) per IQR increase in childhood exposure to road traffic noise and air pollution, respectively. Conclusions This study suggests that residential exposure to road traffic noise and air pollution is associated with higher risk for febrile seizures.

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

Weaver, Virginia M., E-mail: vweaver@jhsph.edu; Johns Hopkins University School of Medicine, Baltimore, MD; Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD

Positive associations between urine toxicant levels and measures of glomerular filtration rate (GFR) have been reported recently in a range of populations. The explanation for these associations, in a direction opposite that of traditional nephrotoxicity, is uncertain. Variation in associations by urine concentration adjustment approach has also been observed. Associations of urine cadmium, thallium and uranium in models of serum creatinine- and cystatin-C-based estimated GFR (eGFR) were examined using multiple linear regression in a cross-sectional study of adolescents residing near a lead smelter complex. Urine concentration adjustment approaches compared included urine creatinine, urine osmolality and no adjustment. Median age, bloodmore » lead and urine cadmium, thallium and uranium were 13.9 years, 4.0 μg/dL, 0.22, 0.27 and 0.04 g/g creatinine, respectively, in 512 adolescents. Urine cadmium and thallium were positively associated with serum creatinine-based eGFR only when urine creatinine was used to adjust for urine concentration (β coefficient=3.1 mL/min/1.73 m{sup 2}; 95% confidence interval=1.4, 4.8 per each doubling of urine cadmium). Weaker positive associations, also only with urine creatinine adjustment, were observed between these metals and serum cystatin-C-based eGFR and between urine uranium and serum creatinine-based eGFR. Additional research using non-creatinine-based methods of adjustment for urine concentration is necessary. - Highlights: • Positive associations between urine metals and creatinine-based eGFR are unexpected. • Optimal approach to urine concentration adjustment for urine biomarkers uncertain. • We compared urine concentration adjustment methods. • Positive associations observed only with urine creatinine adjustment. • Additional research using non-creatinine-based methods of adjustment needed.« less

Adjusting survival time estimates to account for treatment switching in randomized controlled trials--an economic evaluation context: methods, limitations, and recommendations.

PubMed

Latimer, Nicholas R; Abrams, Keith R; Lambert, Paul C; Crowther, Michael J; Wailoo, Allan J; Morden, James P; Akehurst, Ron L; Campbell, Michael J

2014-04-01

Treatment switching commonly occurs in clinical trials of novel interventions in the advanced or metastatic cancer setting. However, methods to adjust for switching have been used inconsistently and potentially inappropriately in health technology assessments (HTAs). We present recommendations on the use of methods to adjust survival estimates in the presence of treatment switching in the context of economic evaluations. We provide background on the treatment switching issue and summarize methods used to adjust for it in HTAs. We discuss the assumptions and limitations associated with adjustment methods and draw on results of a simulation study to make recommendations on their use. We demonstrate that methods used to adjust for treatment switching have important limitations and often produce bias in realistic scenarios. We present an analysis framework that aims to increase the probability that suitable adjustment methods can be identified on a case-by-case basis. We recommend that the characteristics of clinical trials, and the treatment switching mechanism observed within them, should be considered alongside the key assumptions of the adjustment methods. Key assumptions include the "no unmeasured confounders" assumption associated with the inverse probability of censoring weights (IPCW) method and the "common treatment effect" assumption associated with the rank preserving structural failure time model (RPSFTM). The limitations associated with switching adjustment methods such as the RPSFTM and IPCW mean that they are appropriate in different scenarios. In some scenarios, both methods may be prone to bias; "2-stage" methods should be considered, and intention-to-treat analyses may sometimes produce the least bias. The data requirements of adjustment methods also have important implications for clinical trialists.

Individual-based versus aggregate meta-analysis in multi-database studies of pregnancy outcomes: the Nordic example of selective serotonin reuptake inhibitors and venlafaxine in pregnancy.

PubMed

Selmer, Randi; Haglund, Bengt; Furu, Kari; Andersen, Morten; Nørgaard, Mette; Zoëga, Helga; Kieler, Helle

2016-10-01

Compare analyses of a pooled data set on the individual level with aggregate meta-analysis in a multi-database study. We reanalysed data on 2.3 million births in a Nordic register based cohort study. We compared estimated odds ratios (OR) for the effect of selective serotonin reuptake inhibitors (SSRI) and venlafaxine use in pregnancy on any cardiovascular birth defect and the rare outcome right ventricular outflow tract obstructions (RVOTO). Common covariates included maternal age, calendar year, birth order, maternal diabetes, and co-medication. Additional covariates were added in analyses with country-optimized adjustment. Country adjusted OR (95%CI) for any cardiovascular birth defect in the individual-based pooled analysis was 1.27 (1.17-1.39), 1.17 (1.07-1.27) adjusted for common covariates and 1.15 (1.05-1.26) adjusted for all covariates. In fixed effects meta-analyses pooled OR was 1.29 (1.19-1.41) based on crude country specific ORs, 1.19 (1.09-1.29) adjusted for common covariates, and 1.16 (1.06-1.27) for country-optimized adjustment. In a random effects model the adjusted OR was 1.07 (0.87-1.32). For RVOTO, OR was 1.48 (1.15-1.89) adjusted for all covariates in the pooled data set, and 1.53 (1.19-1.96) after country-optimized adjustment. Country-specific adjusted analyses at the substance level were not possible for RVOTO. Results of fixed effects meta-analysis and individual-based analyses of a pooled dataset were similar in this study on the association of SSRI/venlafaxine and cardiovascular birth defects. Country-optimized adjustment attenuated the estimates more than adjustment for common covariates only. When data are sparse pooled data on the individual level are needed for adjusted analyses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Grid-coordinate generation program

USGS Publications Warehouse

Cosner, Oliver J.; Horwich, Esther

1974-01-01

This program description of the grid-coordinate generation program is written for computer users who are familiar with digital aquifer models. The program computes the coordinates for a variable grid -used in the 'Pinder Model' (a finite-difference aquifer simulator), for input to the CalComp GPCP (general purpose contouring program). The program adjusts the y-value by a user-supplied constant in order to transpose the origin of the model grid from the upper left-hand corner to the lower left-hand corner of the grid. The user has the options of, (1.) choosing the boundaries of the plot; (2.) adjusting the z-values (altitudes) by a constant; (3.) deleting superfluous z-values and (4.) subtracting the simulated surfaces from each other to obtain the decline. Output of this program includes the fixed format CNTL data cards and the other data cards required for input to GPCP. The output from GPCP then is used to produce a potentiometric map or a decline map by means of the CalComp plotter.

Parental Depressive Symptoms and Adolescent Adjustment: A Prospective Test of an Explanatory Model for the Role of Marital Conflict

PubMed Central

Cummings, E. Mark; Cheung, Rebecca Y. M.; Koss, Kalsea; Davies, Patrick T.

2014-01-01

Despite calls for process-oriented models for child maladjustment due to heightened marital conflict in the context of parental depressive symptoms, few longitudinal tests of the mechanisms underlying these relations have been conducted. Addressing this gap, the present study examined multiple factors longitudinally that link parental depressive symptoms to adolescent adjustment problems, building on a conceptual model informed by emotional security theory (EST). Participants were 320 families (158 boys, 162 girls), including mothers and fathers, who took part when their children were in kindergarten (T1), second (T2), seventh (T3), eighth (T4) and ninth (T5) grades. Parental depressive symptoms (T1) were related to changes in adolescents’ externalizing and internalizing symptoms (T5), as mediated by parents’ negative emotional expressiveness (T2), marital conflict (T3), and emotional insecurity (T4). Evidence was thus advanced for emotional insecurity as an explanatory process in the context of parental depressive symptoms. PMID:24652484

Determinants of captan air and dermal exposures among orchard pesticide applicators in the Agricultural Health Study.

PubMed

Hines, Cynthia J; Deddens, James A; Coble, Joseph; Kamel, Freya; Alavanja, Michael C R

2011-07-01

To identify and quantify determinants of captan exposure among 74 private orchard pesticide applicators in the Agricultural Health Study (AHS). To adjust an algorithm used for estimating pesticide exposure intensity in the AHS based on these determinants and to compare the correlation of the adjusted and unadjusted algorithms with urinary captan metabolite levels. External exposure metrics included personal air, hand rinse, and dermal patch samples collected from each applicator on 2 days in 2002-2003. A 24-h urine sample was also collected. Exposure determinants were identified for each external metric using multiple linear regression models via the NLMIXED procedure in SAS. The AHS algorithm was adjusted, consistent with the identified determinants. Mixed-effect models were used to evaluate the correlation between the adjusted and unadjusted algorithm and urinary captan metabolite levels. Consistent determinants of captan exposure were a measure of application size (kilogram of captan sprayed or application method), wearing chemical-resistant (CR) gloves and/or a coverall/suit, repairing spray equipment, and product formulation. Application by airblast was associated with a 4- to 5-fold increase in exposure as compared to hand spray. Exposure reduction to the hands, right thigh, and left forearm from wearing CR gloves averaged ∼80%, to the right and left thighs and right forearm from wearing a coverall/suit by ∼70%. Applicators using wettable powder formulations had significantly higher air, thigh, and forearm exposures than those using liquid formulations. Application method weights in the AHS algorithm were adjusted to nine for airblast and two for hand spray; protective equipment reduction factors were adjusted to 0.2 (CR gloves), 0.3 (coverall/suit), and 0.1 (both). Adjustment of application method, CR glove, and coverall weights in the AHS algorithm based on our exposure determinant findings substantially improved the correlation between the AHS algorithm and urinary metabolite levels.

Determinants of Captan Air and Dermal Exposures among Orchard Pesticide Applicators in the Agricultural Health Study

PubMed Central

Hines, Cynthia J.; Deddens, James A.; Coble, Joseph; Kamel, Freya; Alavanja, Michael C. R.

2011-01-01

Objectives: To identify and quantify determinants of captan exposure among 74 private orchard pesticide applicators in the Agricultural Health Study (AHS). To adjust an algorithm used for estimating pesticide exposure intensity in the AHS based on these determinants and to compare the correlation of the adjusted and unadjusted algorithms with urinary captan metabolite levels. Methods: External exposure metrics included personal air, hand rinse, and dermal patch samples collected from each applicator on 2 days in 2002–2003. A 24-h urine sample was also collected. Exposure determinants were identified for each external metric using multiple linear regression models via the NLMIXED procedure in SAS. The AHS algorithm was adjusted, consistent with the identified determinants. Mixed-effect models were used to evaluate the correlation between the adjusted and unadjusted algorithm and urinary captan metabolite levels. Results: Consistent determinants of captan exposure were a measure of application size (kilogram of captan sprayed or application method), wearing chemical-resistant (CR) gloves and/or a coverall/suit, repairing spray equipment, and product formulation. Application by airblast was associated with a 4- to 5-fold increase in exposure as compared to hand spray. Exposure reduction to the hands, right thigh, and left forearm from wearing CR gloves averaged ∼80%, to the right and left thighs and right forearm from wearing a coverall/suit by ∼70%. Applicators using wettable powder formulations had significantly higher air, thigh, and forearm exposures than those using liquid formulations. Application method weights in the AHS algorithm were adjusted to nine for airblast and two for hand spray; protective equipment reduction factors were adjusted to 0.2 (CR gloves), 0.3 (coverall/suit), and 0.1 (both). Conclusions: Adjustment of application method, CR glove, and coverall weights in the AHS algorithm based on our exposure determinant findings substantially improved the correlation between the AHS algorithm and urinary metabolite levels. PMID:21427168

Axial static mixer

DOEpatents

Sandrock, H.E.

1982-05-06

Static axial mixing apparatus includes a plurality of channels, forming flow paths of different dimensions. The axial mixer includes a flow adjusting device for adjustable selective control of flow resistance of various flow paths in order to provide substantially identical flows through the various channels, thereby reducing nonuniform coating of interior surfaces of the channels. The flow adjusting device may include diaphragm valves, and may further include a pressure regulating system therefor.

Seasonal Influenza Forecasting in Real Time Using the Incidence Decay With Exponential Adjustment Model.

PubMed

Nasserie, Tahmina; Tuite, Ashleigh R; Whitmore, Lindsay; Hatchette, Todd; Drews, Steven J; Peci, Adriana; Kwong, Jeffrey C; Friedman, Dara; Garber, Gary; Gubbay, Jonathan; Fisman, David N

2017-01-01

Seasonal influenza epidemics occur frequently. Rapid characterization of seasonal dynamics and forecasting of epidemic peaks and final sizes could help support real-time decision-making related to vaccination and other control measures. Real-time forecasting remains challenging. We used the previously described "incidence decay with exponential adjustment" (IDEA) model, a 2-parameter phenomenological model, to evaluate the characteristics of the 2015-2016 influenza season in 4 Canadian jurisdictions: the Provinces of Alberta, Nova Scotia and Ontario, and the City of Ottawa. Model fits were updated weekly with receipt of incident virologically confirmed case counts. Best-fit models were used to project seasonal influenza peaks and epidemic final sizes. The 2015-2016 influenza season was mild and late-peaking. Parameter estimates generated through fitting were consistent in the 2 largest jurisdictions (Ontario and Alberta) and with pooled data including Nova Scotia counts (R 0 approximately 1.4 for all fits). Lower R 0 estimates were generated in Nova Scotia and Ottawa. Final size projections that made use of complete time series were accurate to within 6% of true final sizes, but final size was using pre-peak data. Projections of epidemic peaks stabilized before the true epidemic peak, but these were persistently early (~2 weeks) relative to the true peak. A simple, 2-parameter influenza model provided reasonably accurate real-time projections of influenza seasonal dynamics in an atypically late, mild influenza season. Challenges are similar to those seen with more complex forecasting methodologies. Future work includes identification of seasonal characteristics associated with variability in model performance.

Contract Design: Risk Management and Evaluation.

PubMed

Mühlbacher, Axel C; Amelung, Volker E; Juhnke, Christin

2018-01-12

Effective risk adjustment is an aspect that is more and more given weight on the background of competitive health insurance systems and vital healthcare systems. The risk structure of the providers plays a vital role in Pay for Performance. A prerequisite for optimal incentive-based service models is a (partial) dependence of the agent's returns on the provider's gain level. Integrated care systems as well as accountable care organisations (ACOs) in the US and similar concepts in other countries are advocated as an effective method of improving the performance of healthcare systems. These systems outline a payment and care delivery model that intends to tie provider reimbursements to predefined quality metrics. By this the total costs of care shall be reduced. Little is known about the contractual design and the main challenges of delegating "accountability" to these new kinds of organisations and/or contracts. The costs of market utilisation are highly relevant for the conception of healthcare contracts; furthermore information asymmetries and contract-specific investments are an obstacle to the efficient operation of ACOs. A comprehensive literature review on methods of designing contracts in Integrated Care was conducted. The research question in this article focuses on how reimbursement strategies, evaluation of measures and methods of risk adjustment can best be integrated in healthcare contracting. Each integrated care contract includes challenges for both payers and providers without having sufficient empirical data on both sides. These challenges are clinical, administrative or financial nature. Risk adjusted contracts ensure that the reimbursement roughly matches the true costs resulting from the morbidity of a population. If reimbursement of care provider corresponds to the actual expenses for an individual/population the problem of risk selection is greatly reduced. The currently used methods of risk adjustment have widely differing model and forecast accuracy. For this reason, it is necessary to clearly regulate the method of risk adjustment in the integrated care contract. The series of three articles on contract design has shown that coordination and motivation problems in designing healthcare contracts cannot be solved at no-costs. Moreover, it became clear, that complete contracts in healthcare are unrealistic and that contracts do always include certain uncertainties. These are based on the risk of random, and no contracting party can control these risks completely. It is also not possible to fully integrate these risks in the contract or to eliminate these risks by the parties.

Application of satellite data in variational analysis for global cyclonic systems

NASA Technical Reports Server (NTRS)

Achtemeier, G. L.

1987-01-01

The research goal was a variational data assimilation method that incorporates as dynamical constraints, the primitive equations for a moist, convectively unstable atmosphere and the radiative transfer equation. Variables to be adjusted include the three-dimensional vector wind, height, temperature, and moisture from rawinsonde data, and cloud-wind vectors, moisture, and radiance from satellite data. This presents a formidable mathematical problem. In order to facilitate thorough analysis of each of the model components, four variational models that divide the problem naturally according to increasing complexity are defined. Each model is summarized.

High-Resolution Topography of Mercury from Messenger Orbital Stereo Imaging - the Southern Hemisphere Quadrangles

NASA Astrophysics Data System (ADS)

Preusker, F.; Oberst, J.; Stark, A.; Burmeister, S.

2018-04-01

We produce high-resolution (222 m/grid element) Digital Terrain Models (DTMs) for Mercury using stereo images from the MESSENGER orbital mission. We have developed a scheme to process large numbers, typically more than 6000, images by photogrammetric techniques, which include, multiple image matching, pyramid strategy, and bundle block adjustments. In this paper, we present models for map quadrangles of the southern hemisphere H11, H12, H13, and H14.

Determinants of Perceived Stress in Individuals with Obesity: Exploring the Relationship of Potentially Obesity-Related Factors and Perceived Stress

PubMed Central

Junne, Florian; Ziser, Katrin; Giel, Katrin Elisabeth; Schag, Kathrin; Skoda, Eva; Mack, Isabelle; Niess, Andreas; Zipfel, Stephan; Teufel, Martin

2017-01-01

Objective Associations of specific types of stress with increased food intake and subsequent weight gain have been demonstrated in animal models as well as in experimental and epidemiological studies on humans. This study explores the research question of to what extent potentially obesity-related factors determine perceived stress in individuals with obesity. Methods N = 547 individuals with obesity participated in a cross-sectional study assessing perceived stress as the outcome variable and potential determinants of stress related to obesity. Based on the available evidence, a five factorial model of ‘obesity-related obesogenic stressors’ was hypothesized, including the dimensions, ‘drive for thinness’, ‘impulse regulation’, ‘ineffectiveness’, ‘social insecurity’, and ‘body dissatisfaction’. The model was tested using multiple linear regression analyses. Results The five factorial model of ‘potentially obesity-related stressors’ resulted in a total variance explanation of adjusted R² = 0.616 for males and adjusted R² = 0.595 for females for perceived stress. The relative variance contribution of the five included factors differed substantially for the two sexes. Conclusion The findings of this cross-sectional study support the hypothesized, potentially obesity-related factors: ‘drive for thinness’, ‘impulse regulation’, ‘ineffectiveness’, ‘social insecurity’, and ‘body dissatisfaction’ as relevant determinants of perceived stress in individuals with obesity. PMID:28433993

The Influence of Maternal Psychosocial Characteristics on Infant Feeding Styles

PubMed Central

Barrett, Katherine J.; Thompson, Amanda L.; Bentley, Margaret E.

2017-01-01

Maternal feeding styles in infancy and early childhood are associated with children’s later risk for overweight and obesity. Maternal psychosocial factors that influence feeding styles during the complementary feeding period, the time during which infants transition from a milk-based diet to one that includes solid foods and other non-milk products, have received less attention. The present study explores how maternal psychosocial factors—specifically self-esteem, parenting self-efficacy, parenting satisfaction, and depression symptoms—influence mothers’ infant feeding styles at nine months of age, a time during which solid foods eating habits are being established. Participants included 160 low-income, African-American mother-infant pairs in central North Carolina who were enrolled in the Infant Care and Risk of Obesity Study. Regression models tested for associations between maternal psychosocial characteristics and pressuring and restrictive feeding styles. Models were first adjusted for maternal age, education, marital status and obesity status. To account for infant characteristics, models were then adjusted for infant weight-for-length, distress to limitations and activity level scores. Maternal self-esteem was negatively associated with pressuring to soothe. Maternal parenting self-efficacy was positively associated with restriction-diet quality. Maternal parenting satisfaction and depression symptoms were not associated with feeding styles in the final models. Focusing on strengthening maternal self-esteem and parenting self-efficacy may help to prevent the development of less desirable infant feeding styles. PMID:27174251

Optimal race strategy for a 200-m flying sprint in a human-powered vehicle: A case study of a world-record attempt.

PubMed

de Koning, Jos J; van der Zweep, Cees-Jan; Cornelissen, Jesper; Kuiper, Bouke

2013-03-01

Optimal pacing strategy was determined for breaking the world speed record on a human-powered vehicle (HPV) using an energy-flow model in which the rider's physical capacities, the vehicle's properties, and the environmental conditions were included. Power data from world-record attempts were compared with data from the model, and race protocols were adjusted to the results from the model. HPV performance can be improved by using an energy-flow model for optimizing race strategy. A biphased in-run followed by a sprint gave best results.

Symplectic no-core shell-model approach to intermediate-mass nuclei

NASA Astrophysics Data System (ADS)

Tobin, G. K.; Ferriss, M. C.; Launey, K. D.; Dytrych, T.; Draayer, J. P.; Dreyfuss, A. C.; Bahri, C.

2014-03-01

We present a microscopic description of nuclei in the intermediate-mass region, including the proximity to the proton drip line, based on a no-core shell model with a schematic many-nucleon long-range interaction with no parameter adjustments. The outcome confirms the essential role played by the symplectic symmetry to inform the interaction and the winnowing of shell-model spaces. We show that it is imperative that model spaces be expanded well beyond the current limits up through 15 major shells to accommodate particle excitations, which appear critical to highly deformed spatial structures and the convergence of associated observables.

The Vermicelli Handling Test: A Simple Quantitative Measure of Dexterous Forepaw Function in Rats

PubMed Central

Allred, Rachel P.; Adkins, DeAnna L.; Woodlee, Martin T.; Husbands, Lincoln C.; Maldonado, Mónica A.; Kane, Jacqueline R.; Schallert, Timothy; Jones, Theresa A.

2008-01-01

Loss of function in the hands occurs with many brain disorders, but there are few measures of skillful forepaw use in rats available to model these impairments that are both sensitive and simple to administer. Whishaw and Coles (1996) previously described the dexterous manner in which rats manipulate food items with their paws, including thin pieces of pasta. We set out to develop a measure of this food handling behavior that would be quantitative, easy to administer, sensitive to the effects of damage to sensory and motor systems of the CNS and useful for identifying the side of lateralized impairments. When rats handle 7 cm lengths of vermicelli, they manipulate the pasta by repeatedly adjusting the forepaw hold on the pasta piece. As operationally defined, these adjustments can be easily identified and counted by an experimenter without specialized equipment. After unilateral sensorimotor cortex (SMC) lesions, transient middle cerebral artery occlusion (MCAO) and striatal dopamine depleting (6-hydroxydopamine, 6-OHDA) lesions in adult rats, there were enduring reductions in adjustments made with the contralateral forepaw. Additional pasta handling characteristics distinguished between the lesion types. MCAO and 6-OHDA lesions increased the frequency of several identified atypical handling patterns. Severe dopamine depletion increased eating time and adjustments made with the ipsilateral forepaw. However, contralateral forepaw adjustment number most sensitively detected enduring impairments across lesion types. Because of its ease of administration and sensitivity to lateralized impairments in skilled forepaw use, this measure may be useful in rat models of upper extremity impairment. PMID:18325597

Procedures for adjusting regional regression models of urban-runoff quality using local data

USGS Publications Warehouse

Hoos, A.B.; Sisolak, J.K.

1993-01-01

Statistical operations termed model-adjustment procedures (MAP?s) can be used to incorporate local data into existing regression models to improve the prediction of urban-runoff quality. Each MAP is a form of regression analysis in which the local data base is used as a calibration data set. Regression coefficients are determined from the local data base, and the resulting `adjusted? regression models can then be used to predict storm-runoff quality at unmonitored sites. The response variable in the regression analyses is the observed load or mean concentration of a constituent in storm runoff for a single storm. The set of explanatory variables used in the regression analyses is different for each MAP, but always includes the predicted value of load or mean concentration from a regional regression model. The four MAP?s examined in this study were: single-factor regression against the regional model prediction, P, (termed MAP-lF-P), regression against P,, (termed MAP-R-P), regression against P, and additional local variables (termed MAP-R-P+nV), and a weighted combination of P, and a local-regression prediction (termed MAP-W). The procedures were tested by means of split-sample analysis, using data from three cities included in the Nationwide Urban Runoff Program: Denver, Colorado; Bellevue, Washington; and Knoxville, Tennessee. The MAP that provided the greatest predictive accuracy for the verification data set differed among the three test data bases and among model types (MAP-W for Denver and Knoxville, MAP-lF-P and MAP-R-P for Bellevue load models, and MAP-R-P+nV for Bellevue concentration models) and, in many cases, was not clearly indicated by the values of standard error of estimate for the calibration data set. A scheme to guide MAP selection, based on exploratory data analysis of the calibration data set, is presented and tested. The MAP?s were tested for sensitivity to the size of a calibration data set. As expected, predictive accuracy of all MAP?s for the verification data set decreased as the calibration data-set size decreased, but predictive accuracy was not as sensitive for the MAP?s as it was for the local regression models.

Incidence, treatment and survival of patients with craniopharyngioma in the surveillance, epidemiology and end results program

PubMed Central

Zacharia, Brad E.; Bruce, Samuel S.; Goldstein, Hannah; Malone, Hani R.; Neugut, Alfred I.; Bruce, Jeffrey N.

2012-01-01

Craniopharyngioma is a rare primary central nervous system neoplasm. Our objective was to determine factors associated with incidence, treatment, and survival of craniopharyngiomas in the United States. We used the surveillance, epidemiology and end results program (SEER) database to identify patients who received a diagnosis of craniopharyngioma during 2004–2008. We analyzed clinical and demographic information, including age, race, sex, tumor histology, and treatment. Age-adjusted incidence rates and age, sex, and race-adjusted expected survival rates were calculated. We used Cox proportional hazards models to determine the association between covariates and overall survival. We identified 644 patients with a diagnosis of craniopharyngioma. Black race was associated with an age-adjusted relative risk for craniopharyngioma of 1.26 (95% confidence interval [CI], 0.98–1.59), compared with white race. One- and 3-year survival rates of 91.5% (95% CI, 88.9%–93.5%), and 86.2% (95% CI, 82.7%–89.0%) were observed for the cohort; relative survival rates were 92.1% (95% CI, 89.5%–94.0%) and 87.6% (95% CI, 84.1%–90.4%) for 1- and 3-years, respectively. In the multivariable model, factors associated with prolonged survival included younger age, smaller tumor size, subtotal resection, and radiation therapy. Black race, on the other hand, was associated with worse overall survival in the final model. We demonstrated that >85% of patients survived 3 years after diagnosis and that subtotal resection and radiation therapy were associated with prolonged survival. We also noted a higher incidence rate and worse 1- and 3-year survival rates in the black population. Future investigations should examine these racial disparities and focus on evaluating the efficacy of emerging treatment paradigms. PMID:22735773

Performance Measures in Neurosurgical Patient Care: Differing Applications of Patient Safety Indicators.

PubMed

Moghavem, Nuriel; McDonald, Kathryn; Ratliff, John K; Hernandez-Boussard, Tina

2016-04-01

Patient Safety Indicators (PSIs) are administratively coded identifiers of potentially preventable adverse events. These indicators are used for multiple purposes, including benchmarking and quality improvement efforts. Baseline PSI evaluation in high-risk surgeries is fundamental to both purposes. Determine PSI rates and their impact on other outcomes in patients undergoing cranial neurosurgery compared with other surgeries. The Agency for Healthcare Research and Quality (AHRQ) PSI software was used to flag adverse events and determine risk-adjusted rates (RAR). Regression models were built to assess the association between PSIs and important patient outcomes. We identified cranial neurosurgeries based on International Classification of Diseases, Ninth Revision, Clinical Modification codes in California, Florida, New York, Arkansas, and Mississippi State Inpatient Databases, AHRQ, 2010-2011. PSI development, 30-day all-cause readmission, length of stay, hospital costs, and inpatient mortality. A total of 48,424 neurosurgical patients were identified. Procedure indication was strongly associated with PSI development. The neurosurgical population had significantly higher RAR of most PSIs evaluated compared with other surgical patients. Development of a PSI was strongly associated with increased length of stay and hospital cost and, in certain PSIs, increased inpatient mortality and 30-day readmission. In this population-based study, certain accountability measures proposed for use as value-based payment modifiers show higher RAR in neurosurgery patients compared with other surgical patients and were subsequently associated with poor outcomes. Our results indicate that for quality improvement efforts, the current AHRQ risk-adjustment models should be viewed in clinically meaningful stratified subgroups: for profiling and pay-for-performance applications, additional factors should be included in the risk-adjustment models. Further evaluation of PSIs in additional high-risk surgeries is needed to better inform the use of these metrics.

The influence of socioeconomic factors on gender disparities in lower extremity bypass.

PubMed

Sinnamon, Andrew J; Sonnenberg, Elizabeth M; Bartlett, Edmund K; Meise, Chelsey K; Wang, Grace J; Kelz, Rachel R

2014-05-15

Some contend that gender differences in outcomes after lower extremity bypass (LEB) for peripheral arterial disease (PAD) relate to socioeconomic factors (SEFs). Here, we evaluate these disparities with attention to clinically relevant yet understudied SEF. A retrospective cohort study of patients aged >50 y with PAD undergoing LEB was performed using data from Pennsylvania Health care and Cost Containment Council (2003-2011). Multivariable logistic regression modeling was performed to evaluate the association between gender and outcomes with adjustment for potential confounders including SEF such as income, insurance provider, distance to hospital, and race. Generalized estimating equations were used to adjust for hospital clustering. Independent models were developed to examine death or serious morbidity (DSM) and failure-to-rescue (FTR). Of 4202 patients identified, 1510 (36%) were women. SEF differed by gender. DSM was more frequent in women (15.6% versus 12.2%; P = 0.002). There was no association between gender and FTR in univariate analysis (P = 0.49). SEFs were associated with DSM and FTR. After adjustment for potential confounders including SEF, women remained more likely to experience DSM (odds ratio = 1.28; P = 0.01). There remained no significant association between gender and FTR on independent modeling (odds ratio = 0.49; P = 0.11). Women undergoing LEB in the state of Pennsylvania are at increased risk of poor outcomes, which is not completely explained by SEF. Quality of postoperative care does not appear to be different between gender as there was no difference in FTR. To improve these outcomes, efforts should be made to increase awareness of PAD and promote screening among high-risk women to ensure timely diagnosis and referral. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative Outcome Analysis of Penicillin-Based Versus Fluoroquinolone-Based Antibiotic Therapy for Community-Acquired Pneumonia

PubMed Central

Wang, Chi-Chuan; Lin, Chia-Hui; Lin, Kuan-Yin; Chuang, Yu-Chung; Sheng, Wang-Huei

2016-01-01

Abstract Community-acquired pneumonia (CAP) is a common but potentially life-threatening condition, but limited information exists on the effectiveness of fluoroquinolones compared to β-lactams in outpatient settings. We aimed to compare the effectiveness and outcomes of penicillins versus respiratory fluoroquinolones for CAP at outpatient clinics. This was a claim-based retrospective cohort study. Patients aged 20 years or older with at least 1 new pneumonia treatment episode were included, and the index penicillin or respiratory fluoroquinolone therapies for a pneumonia episode were at least 5 days in duration. The 2 groups were matched by propensity scores. Cox proportional hazard models were used to compare the rates of hospitalizations/emergence service visits and 30-day mortality. A logistic model was used to compare the likelihood of treatment failure between the 2 groups. After propensity score matching, 2622 matched pairs were included in the final model. The likelihood of treatment failure of fluoroquinolone-based therapy was lower than that of penicillin-based therapy (adjusted odds ratio [AOR], 0.88; 95% confidence interval [95%CI], 0.77–0.99), but no differences were found in hospitalization/emergence service (ES) visits (adjusted hazard ratio [HR], 1.27; 95% CI, 0.92–1.74) and 30-day mortality (adjusted HR, 0.69; 95% CI, 0.30–1.62) between the 2 groups. The likelihood of treatment failure of fluoroquinolone-based therapy was lower than that of penicillin-based therapy for CAP on an outpatient clinic basis. However, this effect may be marginal. Further investigation into the comparative effectiveness of these 2 treatment options is warranted. PMID:26871827

Speech and pause characteristics associated with voluntary rate reduction in Parkinson's disease and Multiple Sclerosis.

PubMed

Tjaden, Kris; Wilding, Greg

2011-01-01

The primary purpose of this study was to investigate how speakers with Parkinson's disease (PD) and Multiple Sclerosis (MS) accomplish voluntary reductions in speech rate. A group of talkers with no history of neurological disease was included for comparison. This study was motivated by the idea that knowledge of how speakers with dysarthria voluntarily accomplish a reduced speech rate would contribute toward a descriptive model of speaking rate change in dysarthria. Such a model has the potential to assist in identifying rate control strategies to receive focus in clinical treatment programs and also would advance understanding of global speech timing in dysarthria. All speakers read a passage in Habitual and Slow conditions. Speech rate, articulation rate, pause duration, and pause frequency were measured. All speaker groups adjusted articulation time as well as pause time to reduce overall speech rate. Group differences in how voluntary rate reduction was accomplished were primarily one of quantity or degree. Overall, a slower-than-normal rate was associated with a reduced articulation rate, shorter speech runs that included fewer syllables, and longer more frequent pauses. Taken together, these results suggest that existing skills or strategies used by patients should be emphasized in dysarthria training programs focusing on rate reduction. Results further suggest that a model of voluntary speech rate reduction based on neurologically normal speech shows promise as being applicable for mild to moderate dysarthria. The reader will be able to: (1) describe the importance of studying voluntary adjustments in speech rate in dysarthria, (2) discuss how speakers with Parkinson's disease and Multiple Sclerosis adjust articulation time and pause time to slow speech rate. Copyright © 2011 Elsevier Inc. All rights reserved.

Flow adjustment inside homogeneous canopies after a leading edge – An analytical approach backed by LES

DOE PAGES

Kroniger, Konstantin; Banerjee, Tirtha; De Roo, Frederik; ...

2017-10-06

A two-dimensional analytical model for describing the mean flow behavior inside a vegetation canopy after a leading edge in neutral conditions was developed and tested by means of large eddy simulations (LES) employing the LES code PALM. The analytical model is developed for the region directly after the canopy edge, the adjustment region, where one-dimensional canopy models fail due to the sharp change in roughness. The derivation of this adjustment region model is based on an analytic solution of the two-dimensional Reynolds averaged Navier–Stokes equation in neutral conditions for a canopy with constant plant area density (PAD). The main assumptionsmore » for solving the governing equations are separability of the velocity components concerning the spatial variables and the neglection of the Reynolds stress gradients. These two assumptions are verified by means of LES. To determine the emerging model parameters, a simultaneous fitting scheme was applied to the velocity and pressure data of a reference LES simulation. Furthermore a sensitivity analysis of the adjustment region model, equipped with the previously calculated parameters, was performed varying the three relevant length, the canopy height ( h), the canopy length and the adjustment length ( Lc), in additional LES. Even if the model parameters are, in general, functions of h/ Lc, it was found out that the model is capable of predicting the flow quantities in various cases, when using constant parameters. Subsequently the adjustment region model is combined with the one-dimensional model of Massman, which is applicable for the interior of the canopy, to attain an analytical model capable of describing the mean flow for the full canopy domain. As a result, the model is tested against an analytical model based on a linearization approach.« less

Flow adjustment inside homogeneous canopies after a leading edge – An analytical approach backed by LES

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

Kroniger, Konstantin; Banerjee, Tirtha; De Roo, Frederik

A two-dimensional analytical model for describing the mean flow behavior inside a vegetation canopy after a leading edge in neutral conditions was developed and tested by means of large eddy simulations (LES) employing the LES code PALM. The analytical model is developed for the region directly after the canopy edge, the adjustment region, where one-dimensional canopy models fail due to the sharp change in roughness. The derivation of this adjustment region model is based on an analytic solution of the two-dimensional Reynolds averaged Navier–Stokes equation in neutral conditions for a canopy with constant plant area density (PAD). The main assumptionsmore » for solving the governing equations are separability of the velocity components concerning the spatial variables and the neglection of the Reynolds stress gradients. These two assumptions are verified by means of LES. To determine the emerging model parameters, a simultaneous fitting scheme was applied to the velocity and pressure data of a reference LES simulation. Furthermore a sensitivity analysis of the adjustment region model, equipped with the previously calculated parameters, was performed varying the three relevant length, the canopy height ( h), the canopy length and the adjustment length ( Lc), in additional LES. Even if the model parameters are, in general, functions of h/ Lc, it was found out that the model is capable of predicting the flow quantities in various cases, when using constant parameters. Subsequently the adjustment region model is combined with the one-dimensional model of Massman, which is applicable for the interior of the canopy, to attain an analytical model capable of describing the mean flow for the full canopy domain. As a result, the model is tested against an analytical model based on a linearization approach.« less

Flexible Strategies for Coping with Rainfall Variability: Seasonal Adjustments in Cropped Area in the Ganges Basin

PubMed Central

Siderius, Christian; Biemans, Hester; van Walsum, Paul E. V.; van Ierland, Ekko C.; Kabat, Pavel; Hellegers, Petra J. G. J.

2016-01-01

One of the main manifestations of climate change will be increased rainfall variability. How to deal with this in agriculture will be a major societal challenge. In this paper we explore flexibility in land use, through deliberate seasonal adjustments in cropped area, as a specific strategy for coping with rainfall variability. Such adjustments are not incorporated in hydro-meteorological crop models commonly used for food security analyses. Our paper contributes to the literature by making a comprehensive model assessment of inter-annual variability in crop production, including both variations in crop yield and cropped area. The Ganges basin is used as a case study. First, we assessed the contribution of cropped area variability to overall variability in rice and wheat production by applying hierarchical partitioning on time-series of agricultural statistics. We then introduced cropped area as an endogenous decision variable in a hydro-economic optimization model (WaterWise), coupled to a hydrology-vegetation model (LPJmL), and analyzed to what extent its performance in the estimation of inter-annual variability in crop production improved. From the statistics, we found that in the period 1999–2009 seasonal adjustment in cropped area can explain almost 50% of variability in wheat production and 40% of variability in rice production in the Indian part of the Ganges basin. Our improved model was well capable of mimicking existing variability at different spatial aggregation levels, especially for wheat. The value of flexibility, i.e. the foregone costs of choosing not to crop in years when water is scarce, was quantified at 4% of gross margin of wheat in the Indian part of the Ganges basin and as high as 34% of gross margin of wheat in the drought-prone state of Rajasthan. We argue that flexibility in land use is an important coping strategy to rainfall variability in water stressed regions. PMID:26934389

Obesity is associated with fatal coronary heart disease independently of traditional risk factors and deprivation.

PubMed

Logue, Jennifer; Murray, Heather M; Welsh, Paul; Shepherd, James; Packard, Chris; Macfarlane, Peter; Cobbe, Stuart; Ford, Ian; Sattar, Naveed

2011-04-01

The effect of body mass index (BMI) on coronary heart disease (CHD) risk is attenuated when mediators of this risk (such as diabetes, hypertension and hyperlipidaemia) are accounted for. However, there is now evidence of a differential effect of risk factors on fatal and non-fatal CHD events, with markers of inflammation more strongly associated with fatal than non-fatal events. To describe the association with BMI separately for both fatal and non-fatal CHD risk after accounting for classical risk factors and to assess any independent effects of obesity on CHD risk. In the West of Scotland Coronary Prevention Study BMI in 6082 men (mean age 55 years) with hypercholesterolaemia, but no history of diabetes or CVD, was related to the risk of fatal and non-fatal CHD events. After excluding participants with any event in the first 2 years, 1027 non-fatal and 214 fatal CHD events occurred during 14.7 years of follow-up. A minimally adjusted model (age, sex, statin treatment) and a maximally adjusted model (including known CVD risk factors and deprivation) were compared, with BMI 25-27.4 kg/m² as referent. The risk of non-fatal events was similar across all BMI categories in both models. The risk of fatal CHD events was increased in men with BMI 30.0-39.9 kg/m² in both the minimally adjusted model (HR = 1.75 (95% CI 1.12 to 2.74)) and the maximally adjusted model (HR = 1.60 (95% CI 1.02 to 2.53)). These hypothesis generating data suggest that obesity is associated with fatal, but not non-fatal, CHD after accounting for known cardiovascular risk factors and deprivation. Clinical trial registration WOSCOPS was carried out and completed before the requirement for clinical trial registration.

Effects of prenatal cocaine exposure on special education in school-aged children.

PubMed

Levine, Todd P; Liu, Jing; Das, Abhik; Lester, Barry; Lagasse, Linda; Shankaran, Seetha; Bada, Henrietta S; Bauer, Charles R; Higgins, Rosemary

2008-07-01

The objective of this study was to evaluate the effects of prenatal cocaine exposure on special education at age 7 with adjustment for covariates. As part of the prospective, longitudinal, multisite study of children with prenatal cocaine exposure (Maternal Lifestyle Study), school records were reviewed for 943 children at 7 years to determine involvement in special education outcomes: (1) individualized education plan; (2) special education conditions; (3) support services; (4) special education classes; and (5) speech and language services. Logistic regression was used to examine the effect of prenatal cocaine exposure on these outcomes with environmental, maternal, and infant medical variables as covariates, as well as with and without low child IQ. Complete data for each analysis model were available for 737 to 916 children. When controlling for covariates including low child IQ, prenatal cocaine exposure had a significant effect on individualized education plan. When low child IQ was not included in the model, prenatal cocaine exposure had a significant effect on support services. Male gender, low birth weight, white race, and low child IQ also predicted individualized education plan. Low birth weight and low child IQ were significant in all models. White race was also significant in speech and language services. Other covariate effects were model specific. When included in the models, low child IQ accounted for more of the variance and changed the significance of other covariates. Prenatal cocaine exposure increased the likelihood of receiving an individualized education plan and support services, with adjustment for covariates. Low birth weight and low child IQ increased the likelihood of all outcomes. The finding that white children were more likely to get an individualized education plan and speech and language services could indicate a greater advantage in getting educational resources for this population.

Passive smoking and cooking oil fumes (COF) may modify the association between tea consumption and oral cancer in Chinese women.

PubMed

Chen, Fa; He, Baochang; Hu, Zhijian; Huang, Jiangfeng; Liu, Fangping; Yan, Lingjun; Lin, Zheng; Zheng, Xiaoyan; Lin, Lisong; Zhang, Zuofeng; Cai, Lin

2016-05-01

To evaluate the confounding effects of passive smoking and COF exposure on association between tea and oral cancer in Chinese women. A case-control study including 207 female oral cancer cases and 480 age-matched controls was performed in Fujian, China. Data were collected with a structured questionnaire by face-to-face interviews. The effects of tea consumption on oral cancer were, respectively, adjusted for Model-1 and Model-2 using logistic regression analysis. Model-1 did not adjusted for passive smoking and COF; Model-2 included the variables in Model-1, passive smoking and COF. Tea consumption was associated with a decreased risk of oral cancer in females: The OR was 0.498 (95 % CI 0.312-0.795) for Model-1 and 0.565 (95 % CI 0.352-0.907) for Model-2. The ORs for all the categories of tea consumption estimated by Model-2 were slightly higher than Model-1. When stratified by passive smoking, the statistically significant association between tea drinking and oral cancer was only emerged in non-passive smoking women. Stratification by COF found tea drinking was still associated with a decreased risk of oral cancer for women who have light-COF exposure, but an increased risk for those who subjected to heavy exposure. A negative, multiplicative interaction was found between tea consumption and COF exposure for oral cancer, but not found between tea consumption and passive smoking. Tea consumption reduces the risk of oral cancer in Chinese women, but this effect is modified by the carcinogenic effects of passive smoking and COF exposure.

A computer model of the pediatric circulatory system for testing pediatric assist devices.

PubMed

Giridharan, Guruprasad A; Koenig, Steven C; Mitchell, Michael; Gartner, Mark; Pantalos, George M

2007-01-01

Lumped parameter computer models of the pediatric circulatory systems for 1- and 4-year-olds were developed to predict hemodynamic responses to mechanical circulatory support devices. Model parameters, including resistance, compliance and volume, were adjusted to match hemodynamic pressure and flow waveforms, pressure-volume loops, percent systole, and heart rate of pediatric patients (n = 6) with normal ventricles. Left ventricular failure was modeled by adjusting the time-varying compliance curve of the left heart to produce aortic pressures and cardiac outputs consistent with those observed clinically. Models of pediatric continuous flow (CF) and pulsatile flow (PF) ventricular assist devices (VAD) and intraaortic balloon pump (IABP) were developed and integrated into the heart failure pediatric circulatory system models. Computer simulations were conducted to predict acute hemodynamic responses to PF and CF VAD operating at 50%, 75% and 100% support and 2.5 and 5 ml IABP operating at 1:1 and 1:2 support modes. The computer model of the pediatric circulation matched the human pediatric hemodynamic waveform morphology to within 90% and cardiac function parameters with 95% accuracy. The computer model predicted PF VAD and IABP restore aortic pressure pulsatility and variation in end-systolic and end-diastolic volume, but diminish with increasing CF VAD support.

But I Like PE: Factors Associated With Enjoyment of Physical Education Class in Middle School Girls

PubMed Central

Barr-Anderson, Daheia J.; Neumark-Sztainer, Dianne; Schmitz, Kathryn H.; Ward, Dianne S.; Conway, Terry L.; Pratt, Charlotte; Baggett, Chris D.; Lytle, Leslie; Pate, Russell R.

2008-01-01

The current study examined associations between physical education (PE) class enjoyment and sociodemographic, personal, and perceived school environment factors among early adolescent girls. Participants included 1,511 sixth-grade girls who completed baseline assessments for the Trial of Activity in Adolescent Girls, with 50% indicating they enjoyed PE class a lot. Variables positively associated with PE class enjoyment included physical activity level, perceived benefits of physical activity, self-efficacy for leisure time physical activity, and perceived school climate for girls' physical activity as influenced by teachers, while body mass index was inversely associated with PE class enjoyment. After adjusting for all variables in the model, PE class enjoyment was significantly greater in Blacks than in Whites. In model testing, with mutual adjustment for all variables, self-efficacy was the strongest correlate of PE class enjoyment, followed by perceived benefits, race/ethnicity, and teacher's support for girls' physical activity, as compared to boys, at school. The overall model explained 11% of the variance in PE class enjoyment. Findings suggest that efforts to enhance girls' self-efficacy and perceived benefits and to provide a supportive PE class environment that promotes gender equality can potentially increase PE class enjoyment among young girls. PMID:18431947

Radiometric Block Adjusment and Digital Radiometric Model Generation

NASA Astrophysics Data System (ADS)

Pros, A.; Colomina, I.; Navarro, J. A.; Antequera, R.; Andrinal, P.

2013-05-01

In this paper we present a radiometric block adjustment method that is related to geometric block adjustment and to the concept of a terrain Digital Radiometric Model (DRM) as a complement to the terrain digital elevation and surface models. A DRM, in our concept, is a function that for each ground point returns a reflectance value and a Bidirectional Reflectance Distribution Function (BRDF). In a similar way to the terrain geometric reconstruction procedure, given an image block of some terrain area, we split the DRM generation in two phases: radiometric block adjustment and DRM generation. In the paper we concentrate on the radiometric block adjustment step, but we also describe a preliminary DRM generator. In the block adjustment step, after a radiometric pre-calibraton step, local atmosphere radiative transfer parameters, and ground reflectances and BRDFs at the radiometric tie points are estimated. This radiometric block adjustment is based on atmospheric radiative transfer (ART) models, pre-selected BRDF models and radiometric ground control points. The proposed concept is implemented and applied in an experimental campaign, and the obtained results are presented. The DRM and orthophoto mosaics are generated showing no radiometric differences at the seam lines.

Psychosocial and cognitive factors associated with adherence to dietary and fluid restriction regimens by people on chronic haemodialysis.

PubMed

Sensky, T; Leger, C; Gilmour, S

1996-01-01

Failure by people on chronic haemodialysis to adhere adequately to dietary and fluid restrictions can have serious medical consequences. Numerous psychosocial factors possibly associated with adherence have been investigated in previous research. However, most previous studies have examined one or a few variables in isolation, and have tended to focus on sociodemographic variables not easily amenable to intervention. Much previous work has tended to ignore potential differences in adherence between male and female dialysands. Sociodemographic and psychosocial factors associated with adherence to dietary and fluid restrictions were investigated in 45 people on haemodialysis attending one renal unit, excluding those with a residual urine volume > 500 ml/day. Multiple regression analyses were used to estimate the contribution to adherence of a range of variables, including gender, age, duration of dialysis, affective disturbance, past psychiatric history, health locus of control, social adjustment and social supports. Adherence to diet (measured by predialysis serum potassium) and to fluid restriction (interdialysis weight gain) were not linked, and had different psychosocial correlates. Regression models of four different aspects of adherence revealed very distinct psychosocial correlates, with contributions to adherence from complex interactions between psychosocial and cognitive variables, notably gender, age, social adjustment, health locus of control, and depression. The findings cast doubt on the results of many previous studies which have used simple models of adherence. Adherence is likely to be influenced in a complex manner by multiple factors including age, gender, locus of control, social adjustment, and past psychiatric history.

On-orbit figure sensing and figure correction control for 0.5 arc-second adjustable X-ray optics

NASA Astrophysics Data System (ADS)

Reid, Paul

This investigation seeks to develop the technology to directly monitor on-orbit changes to imaging performance of adjustable X-ray optics so as to be able to efficiently correct adverse changes at a level consistent with 0.5 arc-second X-ray telescope imaging. Adjustable X-ray optics employ thin film piezoelectric material deposited on the back of a thin glass Wolter mirror segment to introduce localized stresses in the mirror. These stresses are used in a deterministic way to improve mirror figure from 10 arc-sec, half power diameter (HPD), to 0.5 arc-sec, HPD, without the need for a heavy reaction structure. This is a realizable technology for potential future X-ray telescope missions with 0.5 arc-second resolution and several square meters effective area, such as SMART-X. We are pursuing such mirror development under an existing APRA grant. Here we propose a new investigation to accomplish the monitoring and control of the mirrors by monitoring the health of the piezoelectric actuators of the adjustable optics to a level consistent with 0.5 arcsec imaging. Such measurements are beyond the capability of conventional, thin metal film strain gauges using DC measurements. Instead, we propose to develop the technology to deposit different types of strain gauges (metal film, semiconductor) directly on the piezoelectric cells; to investigate the use of additional thin layers of piezoelectric materials such as lead zirconate titanate or zinc oxide as strain and temperature gauges; and to use AC measurement of strain gauges for precise measurement of piezoelectric adjuster performance. The intent is to use this information to correct changes in mirror shape by adjusting the voltages on the piezoelectric adjustors. Adjustable X-ray optics are designed to meet the challenge of large collecting area and high angular resolution. The mirrors are called adjustable rather than active as mirror figure error is corrected (adjusted) once or infrequently, as opposed to being changed constantly at several cycles/sec (active). In our approach, the mirror figure is corrected based on ground measurements, accounting for figure errors due to mirror manufacturing, mounting induced deformations, modeled gravity release, and modeled on-orbit thermal effects. The piezoelectric strain monitoring we seek to develop in this program extends adjustable mirror technology development, as it enables efficient adjustment and correction of mirror figure on-orbit, as required. This unprecedented level of system robustness will make telescopes less expensive to build because requirements for the non-optical systems can be looser, and it will also make the system more resistant to degradation, promoting mission success. The largest drivers for changes from ground calibration to on-orbit performance are piezoelectric material aging and an unexpected thermal environment (i.e., larger gradients than modeled or other thermal control system problem). Developing the capability to accurately monitor the health of each piezoelectric cell and the local mirror surface temperature will enable the real time sensing of any of these potential issues, help determine the cause, and enable corrections via updating models of on-orbit conditions and re-optimizing the required piezoelectric cell voltages for mirror figure correction. Our 3 year research program includes the development of the strain monitoring technology, its deposition on the adjustable optics, modeling and performance simulation, accelerated lifetime testing, and optical and electrical metrology of sample adjustable optics that incorporate monitoring sensors. Development of the capability to remotely monitor piezo performance and temperature to necessary precision will vastly improve reliability of the SMART-X mission concept, or the sub-arc-second X-ray Surveyor mission described in the 2013 NASA Astrophysics Roadmap, Enduring Quests Daring Visions.

Associations between frequency of bullying involvement and adjustment in adolescence.

PubMed

Gower, Amy L; Borowsky, Iris W

2013-01-01

To examine whether infrequent bullying perpetration and victimization (once or twice a month) are associated with elevated levels of internalizing and externalizing problems and to assess evidence for a minimum frequency threshold for bullying involvement. The analytic sample included 128,681 6th, 9th, and 12th graders who completed the 2010 Minnesota Student Survey. Logistic regression and general linear models examined the association between bullying frequency and adjustment correlates including emotional distress, self-harm, physical fighting, and substance use while controlling for demographic characteristics. Gender and grade were included as moderators. Infrequent bullying perpetration and victimization were associated with increased levels of all adjustment problems relative to those who did not engage in bullying in the past 30 days. Grade moderated many of these findings, with perpetration frequency being more strongly related to substance use, self-harm, and suicidal ideation for 6th graders than 12th graders, whereas victimization frequency was associated with self-harm more strongly for 12th graders than 6th graders. Evidence for minimum thresholds for bullying involvement across all outcomes, grades, and bullying roles was inconsistent. Infrequent bullying involvement may pose risks to adolescent adjustment; thus, clinicians and school personnel should address even isolated instances of bullying behavior. Researchers should reexamine the use of cut points in bullying research in order to more fully understand the nature of bullying in adolescence. These data indicate the need for prevention and intervention programs that target diverse internalizing and externalizing problems for bullies and victims, regardless of bullying frequency. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

The relationship between the C-statistic of a risk-adjustment model and the accuracy of hospital report cards: a Monte Carlo Study.

PubMed

Austin, Peter C; Reeves, Mathew J

2013-03-01

Hospital report cards, in which outcomes following the provision of medical or surgical care are compared across health care providers, are being published with increasing frequency. Essential to the production of these reports is risk-adjustment, which allows investigators to account for differences in the distribution of patient illness severity across different hospitals. Logistic regression models are frequently used for risk adjustment in hospital report cards. Many applied researchers use the c-statistic (equivalent to the area under the receiver operating characteristic curve) of the logistic regression model as a measure of the credibility and accuracy of hospital report cards. To determine the relationship between the c-statistic of a risk-adjustment model and the accuracy of hospital report cards. Monte Carlo simulations were used to examine this issue. We examined the influence of 3 factors on the accuracy of hospital report cards: the c-statistic of the logistic regression model used for risk adjustment, the number of hospitals, and the number of patients treated at each hospital. The parameters used to generate the simulated datasets came from analyses of patients hospitalized with a diagnosis of acute myocardial infarction in Ontario, Canada. The c-statistic of the risk-adjustment model had, at most, a very modest impact on the accuracy of hospital report cards, whereas the number of patients treated at each hospital had a much greater impact. The c-statistic of a risk-adjustment model should not be used to assess the accuracy of a hospital report card.

The relationship between the c-statistic of a risk-adjustment model and the accuracy of hospital report cards: A Monte Carlo study

PubMed Central

Austin, Peter C.; Reeves, Mathew J.

2015-01-01

Background Hospital report cards, in which outcomes following the provision of medical or surgical care are compared across health care providers, are being published with increasing frequency. Essential to the production of these reports is risk-adjustment, which allows investigators to account for differences in the distribution of patient illness severity across different hospitals. Logistic regression models are frequently used for risk-adjustment in hospital report cards. Many applied researchers use the c-statistic (equivalent to the area under the receiver operating characteristic curve) of the logistic regression model as a measure of the credibility and accuracy of hospital report cards. Objectives To determine the relationship between the c-statistic of a risk-adjustment model and the accuracy of hospital report cards. Research Design Monte Carlo simulations were used to examine this issue. We examined the influence of three factors on the accuracy of hospital report cards: the c-statistic of the logistic regression model used for risk-adjustment, the number of hospitals, and the number of patients treated at each hospital. The parameters used to generate the simulated datasets came from analyses of patients hospitalized with a diagnosis of acute myocardial infarction in Ontario, Canada. Results The c-statistic of the risk-adjustment model had, at most, a very modest impact on the accuracy of hospital report cards, whereas the number of patients treated at each hospital had a much greater impact. Conclusions The c-statistic of a risk-adjustment model should not be used to assess the accuracy of a hospital report card. PMID:23295579

Impact of gastrectomy procedural complexity on surgical outcomes and hospital comparisons.

PubMed

Mohanty, Sanjay; Paruch, Jennifer; Bilimoria, Karl Y; Cohen, Mark; Strong, Vivian E; Weber, Sharon M

2015-08-01

Most risk adjustment approaches adjust for patient comorbidities and the primary procedure. However, procedures done at the same time as the index case may increase operative risk and merit inclusion in adjustment models for fair hospital comparisons. Our objectives were to evaluate the impact of surgical complexity on postoperative outcomes and hospital comparisons in gastric cancer surgery. Patients who underwent gastric resection for cancer were identified from a large clinical dataset. Procedure complexity was characterized using secondary procedure CPT codes and work relative value units (RVUs). Regression models were developed to evaluate the association between complexity variables and outcomes. The impact of complexity adjustment on model performance and hospital comparisons was examined. Among 3,467 patients who underwent gastrectomy for adenocarcinoma, 2,171 operations were distal and 1,296 total. A secondary procedure was reported for 33% of distal gastrectomies and 59% of total gastrectomies. Six of 10 secondary procedures were associated with adverse outcomes. For example, patients who underwent a synchronous bowel resection had a higher risk of mortality (odds ratio [OR], 2.14; 95% CI, 1.07-4.29) and reoperation (OR, 2.09; 95% CI, 1.26-3.47). Model performance was slightly better for nearly all outcomes with complexity adjustment (mortality c-statistics: standard model, 0.853; secondary procedure model, 0.858; RVU model, 0.855). Hospital ranking did not change substantially after complexity adjustment. Surgical complexity variables are associated with adverse outcomes in gastrectomy, but complexity adjustment does not affect hospital rankings appreciably. Copyright © 2015 Elsevier Inc. All rights reserved.

Greater Dietary Inflammatory Index score is associated with higher likelihood of chronic kidney disease.

PubMed

Mazidi, Mohsen; Shivappa, Nitin; Wirth, Michael D; Hebert, James R; Kengne, Andre P

2018-07-01

Chronic kidney disease (CKD) is described as a progressive alteration of kidney function, resulting from multiple factors, including behaviours. We investigated the association of the Dietary Inflammatory Index (DII®) with prevalent CKD in adult Americans. National Health and Nutrition Examination Survey participants with measured data on kidney function markers from 2005 to 2012 were included in this study. Prevalent CKD was based on an estimated glomerular filtration rate (eGFR) <60 ml/min per 1·73 m2 or urinary albumin/creatinine≥30 mg/g. Energy-adjusted DII (E-DIITM) scores were calculated from 24-h dietary recalls. Statistical analyses accounted for the survey design and sample weights. We included 21 649 participants, with 1634 (6·8 %) having prevalent CKD. Participants with high E-DII scores had greater BMI, fasting blood glucose and systolic blood pressure, and were more likely to be diabetic or hypertensive (all P<0·001) compared with those with lower E-DII scores. In regression models adjusted for age, sex, race, fasting blood glucose, blood pressure, BMI, hypertension and diabetes status, mean eGFR significantly decreased across increasing quartiles of E-DII, whereas serum uric acid level and log urinary albumin:creatinine ratio significantly increased (all P<0·001). Prevalent CKD increased from 5·3 % in the lowest to 9·3 % in the highest E-DII quartile (P=0·02). In multivariable-adjusted logistic regression models, the odds of prevalent CKD were 29 % higher in the highest compared with the lowest E-DII quartile. Pro-inflammatory diet is associated with declining kidney function and high prevalence of CKD. Dietary changes that reduce inflammation have a potential to prevent CKD.

The association of nonalcoholic fatty liver disease with central and peripheral blood pressure in adolescence: findings from a cross-sectional study

PubMed Central

Patel, Sumaiya; Lawlor, Debbie A.; Ferreira, Diana L.S.; Hughes, Alun D.; Chaturvedi, Nish; Callaway, Mark; Day, Chris; Sattar, Naveed; Fraser, Abigail

2015-01-01

Objectives: We aimed to determine the association of nonalcoholic fatty liver disease (NAFLD) with central and peripheral blood pressure (BP), in a general adolescent population and to examine whether associations are independent of adiposity. Methods: Using cross-sectional data from a subsample (N = 1904) of a UK birth cohort, we assessed markers of NAFLD including ultrasound scan (USS) determined fatty liver, shear velocity (marker of liver fibrosis), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) at a mean age of 17.8 years. These were related to BP [central and peripheral SBP and DBP and mean arterial pressure (MAP)]. Results: Fatty liver was positively associated with central and peripheral SBP, DBP and MAP in models adjusting for age, sex, social class, puberty and alcohol intake. These positive associations were attenuated to the null when fat mass was included. For example, in confounder-adjusted models, not including fat mass, mean central SBP was 3.74 mmHg [95% confidence interval (CI) 1.12 to 6.36] higher in adolescents with USS fatty liver than in those without; with additional adjustment for fat mass, the association attenuated to the null value (−0.37 mmHg; 95% CI –3.09 to 2.36). Similar patterns were found for associations of ALT and GGT with central and peripheral BP. There was no consistent evidence of associations of shear velocity or AST with BP measurements. Fatty liver was not consistently associated with central pulse pressure (PP), peripheral PP and Aix@75. Conclusion: NAFLD is not associated with higher central or peripheral BP in adolescents once confounding by adiposity is taken into account. PMID:25426570

Bleeding risk under selective serotonin reuptake inhibitor (SSRI) antidepressants: A meta-analysis of observational studies.

PubMed

Laporte, Silvy; Chapelle, Céline; Caillet, Pascal; Beyens, Marie-Noëlle; Bellet, Florelle; Delavenne, Xavier; Mismetti, Patrick; Bertoletti, Laurent

2017-04-01

Selective serotonin reuptake inhibitors (SSRIs) have been reported to be potentially associated with an increased risk of bleeding. A meta-analysis of observational studies was conducted to quantify this risk. Case-control and cohort studies investigating bleeding risk under SSRI therapy were retrieved by searching the Medline, Pascal, Google Scholar and Scopus databases. Case-control studies were included if they reported bleeding incidents with and without the use of SSRIs and cohort studies were included if they reported the rate of bleeds among SSRI users and non-users. The main outcome was severe bleeding, whatever the site. Only data concerning SSRI belonging to the ATC class N06AB were used. For both case-control and cohort studies, we recorded the adjusted effect estimates and their 95% confidence intervals (CI). Pooled adjusted odds ratio (OR) estimates were computed for case-control and cohort studies using an inverse-variance model. Meta-analysis of the adjusted ORs of 42 observational studies showed a significant association between SSRI use and the risk of bleeding [OR 1.41 (95% CI 1.27-1.57), random effect model, p<0.0001]. The association was found for the 31 case-control studies (1,255,073 patients), with an increased risk of 41% of bleeding [OR 1.41 (95% CI 1.25-1.60)], as well as for the 11 cohort studies including 187,956 patients [OR 1.36 (95% CI 1.12-1.64)]. Subgroup analyses showed that the association remained constant whatever the characteristics of studies. This meta-analysis shows an increased risk of bleeding of at least 36% (from 12% to 64%) based on the high-level of observational studies with SSRIs use. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model: Part 1—Statistical Methodology

PubMed Central

O’Brien, Sean M.; Jacobs, Jeffrey P.; Pasquali, Sara K.; Gaynor, J. William; Karamlou, Tara; Welke, Karl F.; Filardo, Giovanni; Han, Jane M.; Kim, Sunghee; Shahian, David M.; Jacobs, Marshall L.

2016-01-01

Background This study’s objective was to develop a risk model incorporating procedure type and patient factors to be used for case-mix adjustment in the analysis of hospital-specific operative mortality rates after congenital cardiac operations. Methods Included were patients of all ages undergoing cardiac operations, with or without cardiopulmonary bypass, at centers participating in The Society of Thoracic Surgeons Congenital Heart Surgery Database during January 1, 2010, to December 31, 2013. Excluded were isolated patent ductus arteriosus closures in patients weighing less than or equal to 2.5 kg, centers with more than 10% missing data, and patients with missing data for key variables. Data from the first 3.5 years were used for model development, and data from the last 0.5 year were used for assessing model discrimination and calibration. Potential risk factors were proposed based on expert consensus and selected after empirically comparing a variety of modeling options. Results The study cohort included 52,224 patients from 86 centers with 1,931 deaths (3.7%). Covariates included in the model were primary procedure, age, weight, and 11 additional patient factors reflecting acuity status and comorbidities. The C statistic in the validation sample was 0.858. Plots of observed-vs-expected mortality rates revealed good calibration overall and within subgroups, except for a slight overestimation of risk in the highest decile of predicted risk. Removing patient preoperative factors from the model reduced the C statistic to 0.831 and affected the performance classification for 12 of 86 hospitals. Conclusions The risk model is well suited to adjust for case mix in the analysis and reporting of hospital-specific mortality for congenital heart operations. Inclusion of patient factors added useful discriminatory power and reduced bias in the calculation of hospital-specific mortality metrics. PMID:26245502

Bundle adjustment with raw inertial observations in UAV applications

NASA Astrophysics Data System (ADS)

Cucci, Davide Antonio; Rehak, Martin; Skaloud, Jan

2017-08-01

It is well known that accurate aerial position and attitude control is beneficial for image orientation in airborne photogrammetry. The aerial control is traditionally obtained by Kalman filtering/smoothing inertial and GNSS observations prior to the bundle-adjustment. However, in Micro Aerial Vehicles this process may result in poor attitude determination due to the limited quality of the inertial sensors, large alignment uncertainty and residual correlations between sensor biases and initial attitude. We propose to include the raw inertial observations directly into the bundle-adjustment instead of as position and attitude weighted observations from a separate inertial/GNSS fusion step. The necessary observation models are derived in detail within the context of the so called "Dynamic Networks". We examine different real world cases and we show that the proposed approach is superior to the established processing pipeline in challenging scenarios such as mapping in corridors and in areas where the reception of GNSS signals is denied.

Efficacy of Sibling Preparation Classes.

PubMed

Beyers-Carlson, Emma E A; Volling, Brenda L

To examine the effectiveness of sibling preparation classes to facilitate the adjustment of a firstborn child to the birth of a sibling. Longitudinal study with five measurement occasions: third trimester of the mother's pregnancy and 1, 4, 8, and 12 months after the sibling's birth. Communities in southeastern Michigan. A total of 241 families, including mothers, fathers, and firstborn children. Mothers and fathers completed questionnaires to assess changes in children's adjustment. Parents were also asked about their children's attendance at a sibling preparation class focused specifically on preparation for the newborn. Effects of attendance were tested using linear mixed models. Other than avoidance of the infant, children who attended sibling preparation classes did not differ from children who did not attend. Sibling preparation classes for adjustment after the birth of an infant sibling had few effects on participants. Copyright © 2017 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

Controlled cooling of an electronic system for reduced energy consumption

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

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the coolingmore » system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.« less

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

David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the coolingmore » system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.« less

Hypertension and the risk of endometrial cancer: a systematic review and meta-analysis of case-control and cohort studies.

PubMed

Aune, Dagfinn; Sen, Abhijit; Vatten, Lars J

2017-04-07

A history of hypertension has been associated with increased risk of endometrial cancer in several studies, but the results have not been consistent. We conducted a systematic review and meta-analysis of case-control and cohort studies to clarify the association between hypertension and endometrial cancer risk. PubMed and Embase databases were searched up to 27 th of February 2016. Prospective and case-control studies which reported adjusted relative risk estimates and 95% confidence intervals of endometrial cancer associated with a hypertension diagnosis were included. Summary relative risks were estimated using a random effects model. Nineteen case-control studies and 6 cohort studies were included. The summary RR was 1.61 (95% CI: 1.41-1.85, I 2  = 86%) for all studies, 1.73 (95% CI: 1.45-2.06, I 2  = 89%) for case-control studies and 1.32 (95% CI: 1.12-1.56, I 2  = 47%) for cohort studies. The association between hypertension and endometrial cancer was weaker, but still significant, among studies with adjustment for smoking, BMI, oral contraceptive use, and parity, compared to studies without such adjustment. This meta-analysis suggest an increased risk of endometrial cancer among patients with hypertension, however, further studies with more comprehensive adjustments for confounders are warranted to clarify the association.

Assessing uncertainty in published risk estimates using ...

EPA Pesticide Factsheets

Introduction: The National Research Council recommended quantitative evaluation of uncertainty in effect estimates for risk assessment. This analysis considers uncertainty across model forms and model parameterizations with hexavalent chromium [Cr(VI)] and lung cancer mortality as an example. The objective is to characterize model uncertainty by evaluating estimates across published epidemiologic studies of the same cohort.Methods: This analysis was based on 5 studies analyzing a cohort of 2,357 workers employed from 1950-74 in a chromate production plant in Maryland. Cox and Poisson models were the only model forms considered by study authors to assess the effect of Cr(VI) on lung cancer mortality. All models adjusted for smoking and included a 5-year exposure lag, however other latency periods and model covariates such as age and race were considered. Published effect estimates were standardized to the same units and normalized by their variances to produce a standardized metric to compare variability within and between model forms. A total of 5 similarly parameterized analyses were considered across model form, and 16 analyses with alternative parameterizations were considered within model form (10 Cox; 6 Poisson). Results: Across Cox and Poisson model forms, adjusted cumulative exposure coefficients (betas) for 5 similar analyses ranged from 2.47 to 4.33 (mean=2.97, σ2=0.63). Within the 10 Cox models, coefficients ranged from 2.53 to 4.42 (mean=3.29, σ2=0.

A hybrid approach to modeling and control of vehicle height for electronically controlled air suspension

NASA Astrophysics Data System (ADS)

Sun, Xiaoqiang; Cai, Yingfeng; Wang, Shaohua; Liu, Yanling; Chen, Long

2016-01-01

The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

A simple dynamic subgrid-scale model for LES of particle-laden turbulence

NASA Astrophysics Data System (ADS)

Park, George Ilhwan; Bassenne, Maxime; Urzay, Javier; Moin, Parviz

2017-04-01

In this study, a dynamic model for large-eddy simulations is proposed in order to describe the motion of small inertial particles in turbulent flows. The model is simple, involves no significant computational overhead, contains no adjustable parameters, and is flexible enough to be deployed in any type of flow solvers and grids, including unstructured setups. The approach is based on the use of elliptic differential filters to model the subgrid-scale velocity. The only model parameter, which is related to the nominal filter width, is determined dynamically by imposing consistency constraints on the estimated subgrid energetics. The performance of the model is tested in large-eddy simulations of homogeneous-isotropic turbulence laden with particles, where improved agreement with direct numerical simulation results is observed in the dispersed-phase statistics, including particle acceleration, local carrier-phase velocity, and preferential-concentration metrics.

Teenage Parenthood among Child Welfare Clients: A Swedish National Cohort Study of Prevalence and Odds

ERIC Educational Resources Information Center

Vinnerljung, Bo; Franzen, Eva; Danielsson, Maria

2007-01-01

To assess prevalence and odds for teenage parenthood among former child welfare clients, we used national register data for all children born in Sweden 1972-1983 (n = 1,178,207), including 49,582 former child welfare clients with varying intervention experiences. Logistic regression models, adjusted for demographic, socio-economic and familial…

40 CFR 91.210 - End-of-year and final reports.

Code of Federal Regulations, 2010 CFR

2010-07-01

... must include a calculation of credit balances to show that the credit summation is equal to or greater... point of first retail sale (for example, retail customer or dealer) also called the final product... negative credit balances may be adjusted by EPA. (h) If within 270 days of the end of the model year, EPA...

Child Adjustment to Parental Combat Deployment: Risk and Resilience Models

DTIC Science & Technology

2012-03-01

include words even if bottle). FOODS 1. apple 2. banana 3. bread 4. butter 5. cake 6. candy 7. cereal 8. cheese 9~ coffee 10. cookie 11...41. 42. swing 43. teddy bear OUTDOORS 44. flower 45. house moon 47. rain 48. sidewalk 49. sky 50. snow 51. star 52 street I’>Uil tree

Child Sexual Abuse and Adult Romantic Adjustment: Comparison of Single- and Multiple-Indicator Measures

ERIC Educational Resources Information Center

Godbout, Natacha; Sabourin, Stephane; Lussier, Yvan

2009-01-01

This study compared the usefulness of single- and multiple-indicator strategies in a model examining the role of child sexual abuse (CSA) to predict later marital satisfaction through attachment and psychological distress. The sample included 1,092 women and men from a nonclinical population in cohabiting or marital relationships. The single-item…

Equity weights in the allocation of health care: the rank-dependent QALY model.

PubMed

Bleichrodt, Han; Diecidue, Enrico; Quiggin, John

2004-01-01

This paper introduces the rank-dependent quality-adjusted life-years (QALY) model, a new method to aggregate QALYs in economic evaluations of health care. The rank-dependent QALY model permits the formalization of influential concepts of equity in the allocation of health care, such as the fair innings approach, and it includes as special cases many of the social welfare functions that have been proposed in the literature. An important advantage of the rank-dependent QALY model is that it offers a straightforward procedure to estimate equity weights for QALYs. We characterize the rank-dependent QALY model and argue that its central condition has normative appeal.

A model of the human supervisor

NASA Technical Reports Server (NTRS)

Kok, J. J.; Vanwijk, R. A.

1977-01-01

A general model of the human supervisor's behavior is given. Submechanisms of the model include: the observer/reconstructor; decision-making; and controller. A set of hypothesis is postulated for the relations between the task variables and the parameters of the different submechanisms of the model. Verification of the model hypotheses is considered using variations in the task variables. An approach is suggested for the identification of the model parameters which makes use of a multidimensional error criterion. Each of the elements of this multidimensional criterion corresponds to a certain aspect of the supervisor's behavior, and is directly related to a particular part of the model and its parameters. This approach offers good possibilities for an efficient parameter adjustment procedure.

Weekly lottery sales volume and suicide numbers: a time series analysis on national data from Taiwan.

PubMed

Chen, Vincent Chin-Hung; Stewart, Robert; Lee, Charles Tzu-Chi

2012-07-01

To investigate the association between weekly lottery sales and number of suicide deaths in Taiwan. All suicides aged 15+ years during 2004-2006 in Taiwan were included. Poisson autoregression time series models investigated associations of weekly numbers with contemporaneous and recent sales from two national lotteries in operation. Adjustments were made for seasonal fluctuation, temperature, monthly unemployment and autocorrelation. In fully adjusted models, suicide deaths were negatively correlated with sales of tickets for a low-prize, low-cost lottery system. However, they were correlated positively with recent sales for a higher-cost, larger-prize system. Both correlations were stronger for male than female suicide numbers but differed in terms of age groups most strongly implicated. Associations between lottery sales and suicide numbers differed according to the nature of the lottery. A low-prize, low-publicity system appeared to be more benign than a high-prize, high-publicity one.

Adjusting STEMS growth model for Wisconsin forests.

Treesearch

Margaret R. Holdaway

1985-01-01

Describes a simple procedure for adjusting growth in the STEMS regional tree growth model to compensate for subregional differences. Coefficients are reported to adjust Lake States STEMS to the forests of Northern and Central Wisconsin--an area of essentially uniform climate and similar broad physiographic features. Errors are presented for various combinations of...

Mars-GRAM 2010: Additions and Resulting Improvements

NASA Technical Reports Server (NTRS)

Justh, Hilary L.; Burns, K. Lee

2013-01-01

The Mars Global Reference Atmospheric Model (Mars-GRAM) is an engineering-level atmospheric model widely used for diverse mission applications. Mars-GRAM has been utilized during previous aerobraking operations in the atmosphere of Mars. Mars-GRAM has also been used in the prediction and validation of Mars Pathfinder hypersonic aerodynamics, the aerothermodynamic and entry dynamics studies for Mars Polar Lander, the landing site selection process for the Mars Science Laboratory (MSL), the Mars Aerocapture System Study (MASS) as well as the Aerocapture Technology Assessment Group (TAG). Most recently, Mars-GRAM 2010 was used to develop the onboard atmospheric density estimator that is part of the Autonomous Aerobraking Development Plan. The most recent release of Mars-GRAM 2010 contains several changes including an update to Fortran 90/95 and the addition of adjustment factors. Following the completion of a comparison analysis between Mars-GRAM, Thermal Emission Spectrometer (TES), as well as Mars Global Surveyor (MGS), Mars Odyssey (ODY), and Mars Reconnaissance Orbiter (MRO) aerobraking density data, adjustment factors were added to Mars-GRAM 2010 that alter the input data from National Aeronautics and Space Administration (NASA) Ames Mars General Circulation Model (MGCM) and the University of Michigan Mars Thermospheric General Circulation Model (MTGCM) for the mapping year 0 user-controlled dust case. The addition of adjustment factors resolved the issue of previous versions of Mars-GRAM being less than realistic when used for sensitivity studies for mapping year 0 and large optical depth values, such as tau equal to 3. Mars-GRAM was evaluated at locations and times of TES limb observations and adjustment factors were determined. For altitudes above 80 km and below 135 km, Mars-GRAM (MTGCM) densities were compared to aerobraking densities measured by Mars Global Surveyor (MGS), Mars Odyssey (ODY), and Mars Reconnaissance Orbiter (MRO) to determine the adjustment factors. The adjustment factors generated by this process had to satisfy the gas law as well as the hydrostatic relation and are expressed as a function of height (z), Latitude (Lat) and areocentric solar longitude (Ls). The greatest adjustments are made at large optical depths such as tau greater than 1. The addition of the adjustment factors has led to better correspondence to TES Limb data from 0-60 km altitude as well as better agreement with MGS, ODY and MRO data at approximately 90-130 km altitude. Improved Mars-GRAM atmospheric simulations for various locations, times and dust conditions on Mars will be presented at the workshop session. The latest results validating Mars-GRAM 2010 versus Mars Climate Sounder data will also be presented. Mars-GRAM 2010 updates have resulted in improved atmospheric simulations which will be very important when beginning systems design, performance analysis, and operations planning for future aerocapture, aerobraking or landed missions to Mars.

Failed reciprocity in close social relationships and health: findings from the Whitehall II study.

PubMed

Chandola, Tarani; Marmot, Michael; Siegrist, Johannes

2007-10-01

To extend the model of effort-reward imbalance at work to close and more general social relationships and test the associations with different measures of health. Lack of reciprocity at work is associated with poorer health in a number of studies. However, few studies have analysed the effect of nonreciprocity in other kinds of social relationships on health. The Whitehall II Study is an ongoing prospective study of British civil servants (n=10308 at baseline in 1985-88). Cross-sectional data from the latest phase (7, n=6944 in 2002-04) were used in the analyses. The main exposure was a questionnaire measuring nonreciprocal social relations in partnership, parent-children, and general trusting relationships. Health measures included the SF-36 mental and physical component scores, General Health Questionnaire-30 depression subscale, Jenkins' Sleep disturbance questionnaire, and the Rose Angina questionnaire. Logistic and linear regression models were analysed, adjusted for potential confounders, and mediators of the association. Lack of reciprocity is associated with all measures of poorer health. This association attenuates after adjustment for previous health and additional confounders and mediators but remains significant in a majority of models. Negative social support from a close person is independently associated with reduced health, but adjusting for this effect does not eliminate the association of nonreciprocity with poor health. The effort-reward imbalance at work model has been extended to close and more general social relationships. Lack of reciprocity in partnership, parent-children and general trusting relationships is associated with poorer health.

New Utility for an Old Tool

PubMed Central

Odonkor, Charles A.; Schonberger, Robert B.; Dai, Feng; Shelley, Kirk H.; Silverman, David G.; Barash, Paul G.

2013-01-01

Objective The primary aim of this study was to design prediction models based on a functional marker (preoperative gait-speed) to predict readiness for home discharge time of ≤ 90 minutes, and to identify those at risk for unplanned admissions, after elective ambulatory surgery. Design This prospective observational cohort study evaluated all patients scheduled for elective ambulatory surgery. Home discharge readiness and unplanned admissions were the primary outcomes. Independent variables included preoperative gait speed, heart rate, and total anesthesia time. The relationship between all predictors and each primary outcome was determined in separate multivariable logistic regression models. Results After adjustment for covariates, gait speed with adjusted odds ratio = 3.71 (95% CI: 1.21-11.26), p=0.02; was independently associated with early home discharge readiness ≤90 minutes. Importantly, gait speed dichotomized as greater or less than 1 m/s predicted unplanned admissions with odds ratio = 0.35 (95% CI: 0.16 to 0.76, p=0.008) for those with speeds ≥ 1 m/s in comparison to those with speed < 1 m/s. In a separate model, prior history of cardiac surgery with adjusted odds ratio =7.5 (95% CI: 2.34-24.41)(p=0.001) was independently associated with unplanned admissions after elective ambulatory surgery, when other covariates were held constant. Conclusions This study demonstrates use of novel prediction models based on gait speed testing to predict early home discharge and to identify those patients at risk for unplanned admissions, after elective ambulatory surgery. PMID:24051992

Sensitivity analysis of a multilayer, finite-difference model of the Southeastern Coastal Plain regional aquifer system; Mississippi, Alabama, Georgia, and South Carolina

USGS Publications Warehouse

Pernik, Meribeth

1987-01-01

The sensitivity of a multilayer finite-difference regional flow model was tested by changing the calibrated values for five parameters in the steady-state model and one in the transient-state model. The parameters that changed under the steady-state condition were those that had been routinely adjusted during the calibration process as part of the effort to match pre-development potentiometric surfaces, and elements of the water budget. The tested steady-state parameters include: recharge, riverbed conductance, transmissivity, confining unit leakance, and boundary location. In the transient-state model, the storage coefficient was adjusted. The sensitivity of the model to changes in the calibrated values of these parameters was evaluated with respect to the simulated response of net base flow to the rivers, and the mean value of the absolute head residual. To provide a standard measurement of sensitivity from one parameter to another, the standard deviation of the absolute head residual was calculated. The steady-state model was shown to be most sensitive to changes in rates of recharge. When the recharge rate was held constant, the model was more sensitive to variations in transmissivity. Near the rivers, the riverbed conductance becomes the dominant parameter in controlling the heads. Changes in confining unit leakance had little effect on simulated base flow, but greatly affected head residuals. The model was relatively insensitive to changes in the location of no-flow boundaries and to moderate changes in the altitude of constant head boundaries. The storage coefficient was adjusted under transient conditions to illustrate the model 's sensitivity to changes in storativity. The model is less sensitive to an increase in storage coefficient than it is to a decrease in storage coefficient. As the storage coefficient decreased, the aquifer drawdown increases, the base flow decreased. The opposite response occurred when the storage coefficient was increased. (Author 's abstract)

Adolescent RSA Responses during an Anger Discussion Task: Relations to Emotion Regulation and Adjustment

PubMed Central

Cui, Lixian; Morris, Amanda Sheffield; Harrist, Amanda W.; Larzelere, Robert E.; Criss, Michael M.; Houltberg, Benjamin J.

2015-01-01

The current study examined associations between adolescent respiratory sinus arrhythmia (RSA) during an angry event discussion task and adolescents’ emotion regulation and adjustment. Data were collected from 206 adolescents (10–18 years old, M age = 13.37). Electrocardiogram (ECG) and respiration data were collected from adolescents, and RSA values and respiration rates were computed. Adolescents reported on their own emotion regulation, prosocial behavior, and aggressive behavior. Multi-level latent growth modeling was employed to capture RSA responses across time (i.e., linear and quadratic changes; time course approach), and adolescent emotion regulation and adjustment variables were included in the model to test their links to RSA responses. Results indicated that high RSA baseline was associated with more adolescent prosocial behavior. A pattern of initial RSA decreases (RSA suppression) in response to angry event recall and subsequent RSA increases (RSA rebound) were related to better anger and sadness regulation and more prosocial behavior. However, RSA was not significantly linked to adolescent aggressive behavior. We also compared the time course approach with the conventional linear approach and found that the time course approach provided more meaningful and rich information. The implications of adaptive RSA change patterns are discussed. PMID:25642723

Explanatory Model of Resilience in Pediatric Burn Survivors.

PubMed

Quezada, Lucía; González, Mónica T; Mecott, Gabriel A

2016-01-01

Identifying factors of adjustment in pediatric burn patients may facilitate appropriate mental health interventions postinjury. The aim of this is study was to explore the roles of both the patient's and caregivers' resilience and posttraumatic stress in pediatric burn survivor adjustment. For the purposes of the study, "51 patient-parent/guardian" dyads participated. Patients answered the Resilience Questionnaire for Children and Adolescents, and caregivers answered the Mexican Resilience Scale and the Davidson Trauma Scale. The roles of patient age, time since the burn, and size of burn injury were also considered. Statistical analyses included Spearman's ρ for correlations and structural equation modeling. P less than .05 was considered significant. Patients and caregivers reported high levels of resilience, and the majority of caregivers reported low severity of posttraumatic stress disorder symptoms. Pediatric burn survivors' resilience was associated with being younger at the time of the burn and less severity of intrusive and avoidance symptoms in caregivers; it was also associated with a higher resilience in caregivers. It can be concluded that psychological responses of caregivers of pediatric burn survivors affect the well being and positive adjustment of patients; thus psychological services for caregivers would likely have a double benefit for both caregivers and patients.

The spatial and temporal association of neighborhood drug markets and rates of sexually transmitted infections in an urban setting.

PubMed

Jennings, Jacky M; Woods, Stacy E; Curriero, Frank C

2013-09-01

This study examined temporal and spatial relationships between neighborhood drug markets and gonorrhea among census block groups from 2002 to 2005. This was a spatial, longitudinal ecologic study. Poisson regression was used with adjustment in final models for socioeconomic status, residential stability and vacant housing. Increased drug market arrests were significantly associated with a 11% increase gonorrhea (adjusted relative risk (ARR) 1.11; 95% CI 1.05, 1.16). Increased drug market arrests in adjacent neighborhoods were significantly associated with a 27% increase in gonorrhea (ARR 1.27; 95% CI 1.16, 1.36), independent of focal neighborhood drug markets. Increased drug market arrests in the previous year in focal neighborhoods were not associated with gonorrhea (ARR 1.04; 95% CI 0.98, 1.10), adjusting for focal and adjacent drug markets. While the temporal was not supported, our findings support an associative link between drug markets and gonorrhea. The findings suggest that drug markets and their associated sexual networks may extend beyond local neighborhood boundaries indicating the importance of including spatial lags in regression models investigating these associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Treatment strategies for pelvic organ prolapse: a cost-effectiveness analysis.

PubMed

Hullfish, Kathie L; Trowbridge, Elisa R; Stukenborg, George J

2011-05-01

To compare the relative cost effectiveness of treatment decision alternatives for post-hysterectomy pelvic organ prolapse (POP). A Markov decision analysis model was used to assess and compare the relative cost effectiveness of expectant management, use of a pessary, and surgery for obtaining months of quality-adjusted life over 1 year. Sensitivity analysis was conducted to determine whether the results depended on specific estimates of patient utilities for pessary use, probabilities for complications and other events, and estimated costs. Only two treatment alternatives were found to be efficient choices: initial pessary use and vaginal reconstructive surgery (VRS). Pessary use (including patients that eventually transitioned to surgery) achieved 10.4 quality-adjusted months, at a cost of $10,000 per patient, while VRS obtained 11.4 quality-adjusted months, at $15,000 per patient. Sensitivity analysis demonstrated that these baseline results depended on several key estimates in the model. This analysis indicates that pessary use and VRS are the most cost-effective treatment alternatives for treating post-hysterectomy vaginal prolapse. Additional research is needed to standardize POP outcomes and complications, so that healthcare providers can best utilize cost information in balancing the risks and benefits of their treatment decisions.

The spatial and temporal association of neighborhood drug markets and rates of sexually transmitted infections in an urban setting

PubMed Central

Jennings, Jacky M.; Woods, Stacy E.; Curriero, Frank C.

2013-01-01

This study examined temporal and spatial relationships between neighborhood drug markets and gonorrhea among census block groups from 2002 to 2005. This was a spatial, longitudinal ecologic study. Poisson regression was used with adjustment in final models for socioeconomic status, residential stability and vacant housing. Increased drug market arrests were significantly associated with a 11% increase gonorrhea (Adjusted Relative Risk (ARR) 1.11; 95% CI 1.05, 1.16). Increased drug market arrests in adjacent neighborhoods were significantly associated with a 27% increase in gonorrhea (ARR 1.27; 95% CI 1.16, 1.36), independent of focal neighborhood drug markets. Increased drug market arrests in the previous year in focal neighborhoods were not associated with gonorrhea (ARR 1.04; 95% CI 0.98, 1.10), adjusting for focal and adjacent drug markets. While the temporal was not supported, our findings support an associative link between drug markets and gonorrhea. The findings suggest that drug markets and their associated sexual networks may extend beyond local neighborhood boundaries indicating the importance of including spatial lags in regression models investigating these associations. PMID:23872251

Flexible Fusion Structure-Based Performance Optimization Learning for Multisensor Target Tracking

PubMed Central

Ge, Quanbo; Wei, Zhongliang; Cheng, Tianfa; Chen, Shaodong; Wang, Xiangfeng

2017-01-01

Compared with the fixed fusion structure, the flexible fusion structure with mixed fusion methods has better adjustment performance for the complex air task network systems, and it can effectively help the system to achieve the goal under the given constraints. Because of the time-varying situation of the task network system induced by moving nodes and non-cooperative target, and limitations such as communication bandwidth and measurement distance, it is necessary to dynamically adjust the system fusion structure including sensors and fusion methods in a given adjustment period. Aiming at this, this paper studies the design of a flexible fusion algorithm by using an optimization learning technology. The purpose is to dynamically determine the sensors’ numbers and the associated sensors to take part in the centralized and distributed fusion processes, respectively, herein termed sensor subsets selection. Firstly, two system performance indexes are introduced. Especially, the survivability index is presented and defined. Secondly, based on the two indexes and considering other conditions such as communication bandwidth and measurement distance, optimization models for both single target tracking and multi-target tracking are established. Correspondingly, solution steps are given for the two optimization models in detail. Simulation examples are demonstrated to validate the proposed algorithms. PMID:28481243

Comparing colon cancer outcomes: The impact of low hospital case volume and case-mix adjustment.

PubMed

Fischer, C; Lingsma, H F; van Leersum, N; Tollenaar, R A E M; Wouters, M W; Steyerberg, E W

2015-08-01

When comparing performance across hospitals it is essential to consider the noise caused by low hospital case volume and to perform adequate case-mix adjustment. We aimed to quantify the role of noise and case-mix adjustment on standardized postoperative mortality and anastomotic leakage (AL) rates. We studied 13,120 patients who underwent colon cancer resection in 85 Dutch hospitals. We addressed differences between hospitals in postoperative mortality and AL, using fixed (ignoring noise) and random effects (incorporating noise) logistic regression models with general and additional, disease specific, case-mix adjustment. Adding disease specific variables improved the performance of the case-mix adjustment models for postoperative mortality (c-statistic increased from 0.77 to 0.81). The overall variation in standardized mortality ratios was similar, but some individual hospitals changed considerably. For the standardized AL rates the performance of the adjustment models was poor (c-statistic 0.59 and 0.60) and overall variation was small. Most of the observed variation between hospitals was actually noise. Noise had a larger effect on hospital performance than extended case-mix adjustment, although some individual hospital outcome rates were affected by more detailed case-mix adjustment. To compare outcomes between hospitals it is crucial to consider noise due to low hospital case volume with a random effects model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimizing ACS NSQIP modeling for evaluation of surgical quality and risk: patient risk adjustment, procedure mix adjustment, shrinkage adjustment, and surgical focus.

PubMed

Cohen, Mark E; Ko, Clifford Y; Bilimoria, Karl Y; Zhou, Lynn; Huffman, Kristopher; Wang, Xue; Liu, Yaoming; Kraemer, Kari; Meng, Xiangju; Merkow, Ryan; Chow, Warren; Matel, Brian; Richards, Karen; Hart, Amy J; Dimick, Justin B; Hall, Bruce L

2013-08-01

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) collects detailed clinical data from participating hospitals using standardized data definitions, analyzes these data, and provides participating hospitals with reports that permit risk-adjusted comparisons with a surgical quality standard. Since its inception, the ACS NSQIP has worked to refine surgical outcomes measurements and enhance statistical methods to improve the reliability and validity of this hospital profiling. From an original focus on controlling for between-hospital differences in patient risk factors with logistic regression, ACS NSQIP has added a variable to better adjust for the complexity and risk profile of surgical procedures (procedure mix adjustment) and stabilized estimates derived from small samples by using a hierarchical model with shrinkage adjustment. New models have been developed focusing on specific surgical procedures (eg, "Procedure Targeted" models), which provide opportunities to incorporate indication and other procedure-specific variables and outcomes to improve risk adjustment. In addition, comparative benchmark reports given to participating hospitals have been expanded considerably to allow more detailed evaluations of performance. Finally, procedures have been developed to estimate surgical risk for individual patients. This article describes the development of, and justification for, these new statistical methods and reporting strategies in ACS NSQIP. Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of preoperative immunonutrition on postoperative short-term outcomes of patients with head and neck squamous cell carcinoma.

PubMed

Aeberhard, Carla; Mayer, Catherine; Meyer, Simone; Mueller, Simon Andreas; Schuetz, Philipp; Stanga, Zeno; Giger, Roland

2018-05-01

Patients with head and neck squamous cell carcinoma (HNSCC) often acquire an impaired nutritional status resulting in compromised outcomes. Perioperative immunonutrition may have a positive effect on outcomes after elective surgery. Short-term outcomes before and after implementation of preoperative immunonutrition were retrospectively assessed. Regression models adjusted for outcome predictors were used to compare the length of stay (LOS) in the hospital, local infections, and general complications. Four hundred eleven patients were included (control group = 209 and the intervention group = 202). With immunonutrition, hospital LOS was significantly lower (median 6 vs 8 days; adjusted mean difference of -5.65 days; P < .001) and local infections were significantly reduced (7.4% vs 15.3%; adjusted odds ratio [OR] 0.30; P = .006). Subgroup analysis showed more pronounced effects in patients with previous radiotherapy and extensive surgery. Patients receiving preoperative immunonutrition had a shorter hospital LOS and a lower rate for wound infections and local complications. These effects remained robust after a multivariate adjustment. © 2018 Wiley Periodicals, Inc.

Development Status of Adjustable X-Ray Optics with 0.5 Arcsecond Resolution

NASA Technical Reports Server (NTRS)

Reid, P. B.; ODell, Stephen; Elsner, Ron; Ramsey, Brian; Gubarev, Misha; Aldcroft, T.; Allured, R.; Cotroneo, V.; Johnson-Wilke, R. L.; McMuldroch, S.;

Apparatus for a compact adjustable passive compliant mechanism

DOEpatents

Salisbury, Curt Michael

2015-03-17

Various technologies described herein pertain to an adjustable compliance apparatus. The adjustable compliance apparatus includes a shaft, a sleeve element, and a torsion spring. The sleeve element includes a bore there through, where the shaft is positioned through the bore of the sleeve element. Further, the torsion spring includes a plurality of coils, where the shaft is positioned through the plurality of coils. Moreover, the sleeve element is slidable in an axial direction along the shaft between the torsion spring and the shaft. Accordingly, compliance of the adjustable compliance apparatus is adjustable based on a number of the plurality of coils in contact with the sleeve element as positioned along the shaft within the torsion spring.

Are comparisons of patient experiences across hospitals fair? A study in Veterans Health Administration hospitals.

PubMed

Cleary, Paul D; Meterko, Mark; Wright, Steven M; Zaslavsky, Alan M

2014-07-01

Surveys are increasingly used to assess patient experiences with health care. Comparisons of hospital scores based on patient experience surveys should be adjusted for patient characteristics that might affect survey results. Such characteristics are commonly drawn from patient surveys that collect little, if any, clinical information. Consequently some hospitals, especially those treating particularly complex patients, have been concerned that standard adjustment methods do not adequately reflect the challenges of treating their patients. To compare scores for different types of hospitals after making adjustments using only survey-reported patient characteristics and using more complete clinical and hospital information. We used clinical and survey data from a national sample of 1858 veterans hospitalized for an initial acute myocardial infarction (AMI) in a Department of Veterans Affairs (VA) medical center during fiscal years 2003 and 2004. We used VA administrative data to characterize hospitals. The survey asked patients about their experiences with hospital care. The clinical data included 14 measures abstracted from medical records that are predictive of survival after an AMI. Comparisons of scores across hospitals adjusted only for patient-reported health status and sociodemographic characteristics were similar to those that also adjusted for patient clinical characteristics; the Spearman rank-order correlations between the 2 sets of adjusted scores were >0.97 across 9 dimensions of inpatient experience. This study did not support concerns that measures of patient care experiences are unfair because commonly used models do not adjust adequately for potentially confounding patient clinical characteristics.

The effect of antidepressants on fertility.

PubMed

Casilla-Lennon, Marianne M; Meltzer-Brody, Samantha; Steiner, Anne Z

2016-09-01

Information on the effects of different pharmaceuticals on fertility is sparse. Human and animal models indicate that antidepressant use could have a negative effect on fertility through alteration of levels of the neurosteroid, allopregnanolone. The objective of this study is to assess the effects of antidepressants on the natural fertility in women. A secondary analysis of data from Time to Conceive, a prospective cohort study, was conducted. Women ages 30 to 44 years without a history of infertility, early in their attempts to conceive, were followed with standardized pregnancy testing until pregnancy was detected. Medication use was assessed at enrollment, daily for up to 4 months, and then monthly. For this analysis, discrete time regression models were created to calculate the association between antidepressant use and fecundability. Potential confounders-age, body mass index, caffeine, alcohol use, and education-were included in all models. Ninety-two (9.6%) of 957 women reported antidepressant use while attempting to conceive. Women taking antidepressants were more likely to be non-Hispanic Caucasian (91% vs 75%, P < .01) and to consume alcoholic beverages (74% vs 61%, P < .01). Antidepressant use at enrollment had an adjusted fecundability ratio (FR) of 0.86 (95% confidence interval [CI], 0.63-1.20). However, time-varying analyses suggested that antidepressant use in a given cycle is associated with a reduced probability of conceiving in that cycle (adjusted FR, 0.75; 95% CI, 0.53-1.06). After adjusting for history of depression or restricting the analysis to women who reported a history of depression, the association between antidepressant use and decreased fecundability remained [adjusted FR, 0.66 (95% CI, 0.45-0.97) and (adjusted FR, 0.64; 95% CI, 0.43-0.94), respectively]. Our data suggest that antidepressants may reduce the probability of a woman with a history of depression to conceive naturally. Future studies are needed to differentiate the extent to which this association is due to the antidepressant itself versus the underlying depression. Published by Elsevier Inc.

Risk adjustment models for short-term outcomes after surgical resection for oesophagogastric cancer.

PubMed

Fischer, C; Lingsma, H; Hardwick, R; Cromwell, D A; Steyerberg, E; Groene, O

2016-01-01

Outcomes for oesophagogastric cancer surgery are compared with the aim of benchmarking quality of care. Adjusting for patient characteristics is crucial to avoid biased comparisons between providers. The study objective was to develop a case-mix adjustment model for comparing 30- and 90-day mortality and anastomotic leakage rates after oesophagogastric cancer resections. The study reviewed existing models, considered expert opinion and examined audit data in order to select predictors that were consequently used to develop a case-mix adjustment model for the National Oesophago-Gastric Cancer Audit, covering England and Wales. Models were developed on patients undergoing surgical resection between April 2011 and March 2013 using logistic regression. Model calibration and discrimination was quantified using a bootstrap procedure. Most existing risk models for oesophagogastric resections were methodologically weak, outdated or based on detailed laboratory data that are not generally available. In 4882 patients with oesophagogastric cancer used for model development, 30- and 90-day mortality rates were 2·3 and 4·4 per cent respectively, and 6·2 per cent of patients developed an anastomotic leak. The internally validated models, based on predictors selected from the literature, showed moderate discrimination (area under the receiver operating characteristic (ROC) curve 0·646 for 30-day mortality, 0·664 for 90-day mortality and 0·587 for anastomotic leakage) and good calibration. Based on available data, three case-mix adjustment models for postoperative outcomes in patients undergoing curative surgery for oesophagogastric cancer were developed. These models should be used for risk adjustment when assessing hospital performance in the National Health Service, and tested in other large health systems. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

Identifying Nonprovider Factors Affecting Pediatric Emergency Medicine Provider Efficiency.

PubMed

Saleh, Fareed; Breslin, Kristen; Mullan, Paul C; Tillett, Zachary; Chamberlain, James M

2017-10-31

The aim of this study was to create a multivariable model of standardized relative value units per hour by adjusting for nonprovider factors that influence efficiency. We obtained productivity data based on billing records measured in emergency relative value units for (1) both evaluation and management of visits and (2) procedures for 16 pediatric emergency medicine providers with more than 750 hours worked per year. Eligible shifts were in an urban, academic pediatric emergency department (ED) with 2 sites: a tertiary care main campus and a satellite community site. We used multivariable linear regression to adjust for the impact of shift and pediatric ED characteristics on individual-provider efficiency and then removed variables from the model with minimal effect on productivity. There were 2998 eligible shifts for the 16 providers during a 3-year period. The resulting model included 4 variables when looking at both ED sites combined. These variables include the following: (1) number of procedures billed by provider, (2) season of the year, (3) shift start time, and (4) day of week. Results were improved when we separately modeled each ED location. A 3-variable model using procedures billed by provider, shift start time, and season explained 23% of the variation in provider efficiency at the academic ED site. A 3-variable model using procedures billed by provider, patient arrivals per hour, and shift start time explained 45% of the variation in provider efficiency at the satellite ED site. Several nonprovider factors affect provider efficiency. These factors should be considered when designing productivity-based incentives.

Adverse effects of maternal lead levels on birth outcomes in the ALSPAC study: a prospective birth cohort study.

PubMed

Taylor, C M; Golding, J; Emond, A M

2015-02-01

To study the associations of prenatal blood lead levels (B-Pb) with pregnancy outcomes in a large cohort of mother-child pairs in the UK. Prospective birth cohort study. Avon area of Bristol, UK. Pregnant women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). Whole blood samples were collected and analysed by inductively coupled plasma dynamic reaction cell mass spectrometry (n = 4285). Data collected on the infants included anthropometric variables and gestational age at delivery. Linear regression models for continuous outcomes and logistic regression models for categorical outcomes were adjusted for covariates including maternal height, smoking, parity, sex of the baby and gestational age. Birthweight, head circumference and crown-heel length, preterm delivery and low birthweight. The mean blood lead level (B-Pb) was 3.67 ± 1.47 μg/dl. B-Pb ≥ 5 μg/dl significantly increased the risk of preterm delivery (adjusted odds ratio [OR] 2.00 95% confidence interval [95% CI] 1.35-3.00) but not of having a low birthweight baby (adjusted OR 1.37, 95% CI 0.86-2.18) in multivariable binary logistic models. Increasing B-Pb was significantly associated with reductions in birth weight (β -13.23, 95% CI -23.75 to -2.70), head circumference (β -0.04, 95% CI -0.07 to -0.06) and crown-heel length (β -0.05, 95% CI -0.10 to -0.00) in multivariable linear regression models. There was evidence for adverse effects of maternal B-Pb on the incidence of preterm delivery, birthweight, head circumference and crown-heel length, but not on the incidence of low birthweight, in this group of women. © 2014 The Authors. BJOG An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd on behalf of Royal College of Obstetricians and Gynaecologists.

Cost-utility of cognitive behavioral therapy for low back pain from the commercial payer perspective.

PubMed

Norton, Giulia; McDonough, Christine M; Cabral, Howard; Shwartz, Michael; Burgess, James F

2015-05-15

Markov cost-utility model. To evaluate the cost-utility of cognitive behavioral therapy (CBT) for the treatment of persistent nonspecific low back pain (LBP) from the perspective of US commercial payers. CBT is widely deemed clinically effective for LBP treatment. The evidence is suggestive of cost-effectiveness. We constructed and validated a Markov intention-to-treat model to estimate the cost-utility of CBT, with 1-year and 10-year time horizons. We applied likelihood of improvement and utilities from a randomized controlled trial assessing CBT to treat LBP. The trial randomized subjects to treatment but subjects freely sought health care services. We derived the cost of equivalent rates and types of services from US commercial claims for LBP for a similar population. For the 10-year estimates, we derived recurrence rates from the literature. The base case included medical and pharmaceutical services and assumed gradual loss of skill in applying CBT techniques. Sensitivity analyses assessed the distribution of service utilization, utility values, and rate of LBP recurrence. We compared health plan designs. Results are based on 5000 iterations of each model and expressed as an incremental cost per quality-adjusted life-year. The incremental cost-utility of CBT was $7197 per quality-adjusted life-year in the first year and $5855 per quality-adjusted life-year over 10 years. The results are robust across numerous sensitivity analyses. No change of parameter estimate resulted in a difference of more than 7% from the base case for either time horizon. Including chiropractic and/or acupuncture care did not substantively affect cost-effectiveness. The model with medical but no pharmaceutical costs was more cost-effective ($5238 for 1 yr and $3849 for 10 yr). CBT is a cost-effective approach to manage chronic LBP among commercial health plans members. Cost-effectiveness is demonstrated for multiple plan designs. 2.

Monitoring risk-adjusted outcomes in congenital heart surgery: does the appropriateness of a risk model change with time?

PubMed

Tsang, Victor T; Brown, Katherine L; Synnergren, Mats Johanssen; Kang, Nicholas; de Leval, Marc R; Gallivan, Steve; Utley, Martin

2009-02-01

Risk adjustment of outcomes in pediatric congenital heart surgery is challenging due to the great diversity in diagnoses and procedures. We have previously shown that variable life-adjusted display (VLAD) charts provide an effective graphic display of risk-adjusted outcomes in this specialty. A question arises as to whether the risk model used remains appropriate over time. We used a recently developed graphic technique to evaluate the performance of an existing risk model among those patients at a single center during 2000 to 2003 originally used in model development. We then compared the distribution of predicted risk among these patients with that among patients in 2004 to 2006. Finally, we constructed a VLAD chart of risk-adjusted outcomes for the latter period. Among 1083 patients between April 2000 and March 2003, the risk model performed well at predicted risks above 3%, underestimated mortality at 2% to 3% predicted risk, and overestimated mortality below 2% predicted risk. There was little difference in the distribution of predicted risk among these patients and among 903 patients between June 2004 and October 2006. Outcomes for the more recent period were appreciably better than those expected according to the risk model. This finding cannot be explained by any apparent bias in the risk model combined with changes in case-mix. Risk models can, and hopefully do, become out of date. There is scope for complacency in the risk-adjusted audit if the risk model used is not regularly recalibrated to reflect changing standards and expectations.

Economic evaluations and their use in infection prevention and control: a narrative review.

PubMed

Rennert-May, Elissa; Conly, John; Leal, Jenine; Smith, Stephanie; Manns, Braden

2018-01-01

The objective of this review is to provide a comprehensive overview of the different types of economic evaluations that can be utilized by Infection Prevention and Control practitioners with a particular focus on the use of the quality adjusted life year, and its associated challenges. We also highlight existing economic evaluations published within Infection Prevention and Control, research gaps and future directions. Narrative Review. To date the majority of economic evaluations within Infection Prevention and Control are considered partial economic evaluations. Acknowledging the challenges, which include variable utilities within infection prevention and control, a lack of randomized controlled trials, and difficulty in modelling infectious diseases in general, future economic evaluation studies should strive to be consistent with published guidelines for economic evaluations. This includes the use of quality adjusted life years. Further research is required to estimate utility scores of relevance within Infection Prevention and Control.

Bring It On, Complexity! Present and Future of Self-Organising Middle-Out Abstraction

NASA Astrophysics Data System (ADS)

Mammen, Sebastian Von; Steghöfer, Jan-Philipp

The following sections are included: * The Great Complexity Challenge * Self-Organising Middle-Out Abstraction * Optimising Graphics, Physics and Artificial Intelligence * Emergence and Hierarchies in a Natural System * The Technical Concept of SOMO * Observation of interactions * Interaction pattern recognition and behavioural abstraction * Creating and adjusting hierarchies * Confidence measures * Execution model * Learning SOMO: parameters, knowledge propagation, and procreation * Current Implementations * Awareness Beyond Virtuality * Integration and emergence * Model inference * SOMO net * SOMO after me * The Future of SOMO

Post-Stress Combined Administration of Beta-Receptor and Glucocorticoid Antagonists as a Novel Preventive Treatment in an Animal Model of PTSD

DTIC Science & Technology

2010-05-01

prenatal stress as a factor in vulnerability to develop PTSD upon adult exposure to traumatic stress. Thus, although the duration of this Concept...including fear conditioning and extinction; and 3) test the combined drug treatment using the established model. Although we developed a reliable test...our lab, but had to be modified and adjusted to suit the time frame required by the design of these experiments. Others we had to develop , set up

Attention-Deficit/Hyperactivity Disorder in Offspring of Mothers With Inflammatory and Immune System Diseases.

PubMed

Instanes, Johanne T; Halmøy, Anne; Engeland, Anders; Haavik, Jan; Furu, Kari; Klungsøyr, Kari

2017-03-01

Prenatal inflammatory mechanisms may play a role in the pathogenesis of psychiatric disorders and could be relevant for attention-deficit/hyperactivity disorder (ADHD). We investigated maternal chronic somatic diseases with immune components as possible risk factors for ADHD in offspring. We performed a population-based nested case-control study by linking data from longitudinal Norwegian registers. We included all individuals born during the period 1967-2008 and alive at record linkage (2012). Individuals receiving ADHD medication during the years 2004-2012 were defined as patients with ADHD (N = 47,944), and all remaining individuals (N = 2,274,713) were defined as control subjects. The associations between maternal diseases and ADHD in offspring were analyzed using logistic regression models. The following chronic diseases with immune components were related to ADHD in offspring: multiple sclerosis (adjusted odds ratio [OR] = 1.8; 95% confidence interval [CI] = 1.2-2.5), rheumatoid arthritis (adjusted OR = 1.7; 95% CI = 1.5-1.9), type 1 diabetes (adjusted OR = 1.6; 95% CI = 1.3-2.0), asthma (adjusted OR = 1.5; 95% CI = 1.4-1.6), and hypothyroidism (adjusted OR = 1.2; 95% CI = 1.1-1.4). In contrast, chronic hypertension and type 2 diabetes showed no significant associations. Estimates were almost unchanged with additional adjustment for parental ADHD, infant birth weight, and gestational age. Although point estimates for male and female offspring were different for some diseases (e.g., maternal asthma [adjusted OR = 1.7; 95% CI = 1.5-1.8 for female offspring and adjusted OR = 1.5; 95% CI = 1.4-1.6 for male offspring]), none of the associations differed significantly by offspring sex. Several maternal somatic diseases with immune components were found to increase the risk of ADHD in offspring. The associations could involve several causal pathways, including common genetic predisposition and environmental factors, and increased insight into the mechanisms behind these relationships could enhance our understanding of the etiology of ADHD. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Refining Risk Adjustment for the Proposed CMS Surgical Hip and Femur Fracture Treatment Bundled Payment Program.

PubMed

Cairns, Mark A; Ostrum, Robert F; Clement, R Carter

2018-02-21

The U.S. Centers for Medicare & Medicaid Services (CMS) has been considering the implementation of a mandatory bundled payment program, the Surgical Hip and Femur Fracture Treatment (SHFFT) model. However, bundled payments without appropriate risk adjustment may be inequitable to providers and may restrict access to care for certain patients. The SHFFT proposal includes adjustment using the Diagnosis-Related Group (DRG) and geographic location. The goal of the current study was to identify and quantify patient factors that could improve risk adjustment for SHFFT bundled payments. We retrospectively reviewed a 5% random sample of Medicare data from 2008 to 2012. A total of 27,898 patients were identified who met SHFFT inclusion criteria (DRG 480, 481, and 482). Reimbursement was determined for each patient over the bundle period (the surgical hospitalization and 90 days of post-discharge care). Multivariable regression was performed to test demographic factors, comorbidities, geographic location, and specific surgical procedures for associations with reimbursement. The average reimbursement was $23,632 ± $17,587. On average, reimbursements for male patients were $1,213 higher than for female patients (p < 0.01). Younger age was also associated with higher payments; e.g., reimbursement for those ≥85 years of age averaged $2,282 ± $389 less than for those aged 65 to 69 (p < 0.01). Most comorbidities were associated with higher reimbursement, but dementia was associated with lower payments, by an average of $2,354 ± $243 (p < 0.01). Twenty-two procedure codes are included in the bundle, and patients with the 3 most common codes accounted for 98% of the cases, with average reimbursement ranging from $22,527 to $24,033. Less common procedures varied by >$20,000 in average reimbursement (p < 0.01). DRGs also showed significant differences in reimbursement (p < 0.01); e.g., DRG 480 was reimbursed by an average of $10,421 ± $543 more than DRG 482. Payments varied significantly by state (p ≤ 0.01). Risk adjustment incorporating specific comorbidities demonstrated better performance than with use of DRG alone (r = 0.22 versus 0.15). Our results suggest that the proposed SHFFT bundled payment model should use more robust risk-adjustment methods to ensure that providers are reimbursed fairly and that patients retain access to care. At a minimum, payments should be adjusted for age, comorbidities, demographic factors, geographic location, and surgical procedure.

Obese women less likely to have low serum ferritin, Nicaragua

PubMed Central

Wendt, Amanda S; Jefferds, Maria E; Perrine, Cria G; Halleslevens, Patricia; Sullivan, Kevin M

2015-01-01

Objective To examine the association between overweight and obesity and serum ferritin among women of reproductive age (15–49 years) in Nicaragua, considering the effect of α1-acid glycoprotein (AGP), a marker of inflammation. Design We analysed data from the 2004–05 Nicaraguan Integrated Surveillance System for Nutrition Interventions. Three logistic regression models were analysed with low serum ferritin (<15 μg/l) as the dependent variable: (i) overweight or obese status and covariates; (ii) model 1 plus AGP; and (iii) model 1 restricted to only women with normal AGP levels (≤1·0 g/l). Setting Nicaragua. Subjects Included in this analysis were 832 non-pregnant mother/caregivers (15–49 years) surveyed in 2004–2005. Results In the sample, prevalence of overweight and obesity was 31·8 % and 19·2 %, respectively, and 27·6 % had low serum ferritin. In model 1, the adjusted OR of low serum ferritin was 0·74 (95 % CI 0·52, 1·05) for overweight women and 0·42 (95 % CI 0·26, 0·65) for obese women. In model 2, AGP was significantly independently associated with low serum ferritin (adjusted OR=0·56, 95 % CI 0·34, 0·92) while the adjusted OR for overweight and obesity were largely unchanged. Excluding women with elevated AGP did not appreciably affect the relationship between overweight or obesity and low serum ferritin (model 3). Conclusions Overall, in this population of reproductive-age women, obese women were less likely to have low serum ferritin levels, and this was independent of inflammation as measured by AGP. PMID:24848519

Spiking and bursting patterns of fractional-order Izhikevich model

NASA Astrophysics Data System (ADS)

Teka, Wondimu W.; Upadhyay, Ranjit Kumar; Mondal, Argha

2018-03-01

Bursting and spiking oscillations play major roles in processing and transmitting information in the brain through cortical neurons that respond differently to the same signal. These oscillations display complex dynamics that might be produced by using neuronal models and varying many model parameters. Recent studies have shown that models with fractional order can produce several types of history-dependent neuronal activities without the adjustment of several parameters. We studied the fractional-order Izhikevich model and analyzed different kinds of oscillations that emerge from the fractional dynamics. The model produces a wide range of neuronal spike responses, including regular spiking, fast spiking, intrinsic bursting, mixed mode oscillations, regular bursting and chattering, by adjusting only the fractional order. Both the active and silent phase of the burst increase when the fractional-order model further deviates from the classical model. For smaller fractional order, the model produces memory dependent spiking activity after the pulse signal turned off. This special spiking activity and other properties of the fractional-order model are caused by the memory trace that emerges from the fractional-order dynamics and integrates all the past activities of the neuron. On the network level, the response of the neuronal network shifts from random to scale-free spiking. Our results suggest that the complex dynamics of spiking and bursting can be the result of the long-term dependence and interaction of intracellular and extracellular ionic currents.

Regression model development and computational procedures to support estimation of real-time concentrations and loads of selected constituents in two tributaries to Lake Houston near Houston, Texas, 2005-9

USGS Publications Warehouse

Lee, Michael T.; Asquith, William H.; Oden, Timothy D.

2012-01-01

In December 2005, the U.S. Geological Survey (USGS), in cooperation with the City of Houston, Texas, began collecting discrete water-quality samples for nutrients, total organic carbon, bacteria (Escherichia coli and total coliform), atrazine, and suspended sediment at two USGS streamflow-gaging stations that represent watersheds contributing to Lake Houston (08068500 Spring Creek near Spring, Tex., and 08070200 East Fork San Jacinto River near New Caney, Tex.). Data from the discrete water-quality samples collected during 2005–9, in conjunction with continuously monitored real-time data that included streamflow and other physical water-quality properties (specific conductance, pH, water temperature, turbidity, and dissolved oxygen), were used to develop regression models for the estimation of concentrations of water-quality constituents of substantial source watersheds to Lake Houston. The potential explanatory variables included discharge (streamflow), specific conductance, pH, water temperature, turbidity, dissolved oxygen, and time (to account for seasonal variations inherent in some water-quality data). The response variables (the selected constituents) at each site were nitrite plus nitrate nitrogen, total phosphorus, total organic carbon, E. coli, atrazine, and suspended sediment. The explanatory variables provide easily measured quantities to serve as potential surrogate variables to estimate concentrations of the selected constituents through statistical regression. Statistical regression also facilitates accompanying estimates of uncertainty in the form of prediction intervals. Each regression model potentially can be used to estimate concentrations of a given constituent in real time. Among other regression diagnostics, the diagnostics used as indicators of general model reliability and reported herein include the adjusted R-squared, the residual standard error, residual plots, and p-values. Adjusted R-squared values for the Spring Creek models ranged from .582–.922 (dimensionless). The residual standard errors ranged from .073–.447 (base-10 logarithm). Adjusted R-squared values for the East Fork San Jacinto River models ranged from .253–.853 (dimensionless). The residual standard errors ranged from .076–.388 (base-10 logarithm). In conjunction with estimated concentrations, constituent loads can be estimated by multiplying the estimated concentration by the corresponding streamflow and by applying the appropriate conversion factor. The regression models presented in this report are site specific, that is, they are specific to the Spring Creek and East Fork San Jacinto River streamflow-gaging stations; however, the general methods that were developed and documented could be applied to most perennial streams for the purpose of estimating real-time water quality data.

Nonlinear relative-proportion-based route adjustment process for day-to-day traffic dynamics: modeling, equilibrium and stability analysis

NASA Astrophysics Data System (ADS)

Zhu, Wenlong; Ma, Shoufeng; Tian, Junfang; Li, Geng

2016-11-01

Travelers' route adjustment behaviors in a congested road traffic network are acknowledged as a dynamic game process between them. Existing Proportional-Switch Adjustment Process (PSAP) models have been extensively investigated to characterize travelers' route choice behaviors; PSAP has concise structure and intuitive behavior rule. Unfortunately most of which have some limitations, i.e., the flow over adjustment problem for the discrete PSAP model, the absolute cost differences route adjustment problem, etc. This paper proposes a relative-Proportion-based Route Adjustment Process (rePRAP) maintains the advantages of PSAP and overcomes these limitations. The rePRAP describes the situation that travelers on higher cost route switch to those with lower cost at the rate that is unilaterally depended on the relative cost differences between higher cost route and its alternatives. It is verified to be consistent with the principle of the rational behavior adjustment process. The equivalence among user equilibrium, stationary path flow pattern and stationary link flow pattern is established, which can be applied to judge whether a given network traffic flow has reached UE or not by detecting the stationary or non-stationary state of link flow pattern. The stability theorem is proved by the Lyapunov function approach. A simple example is tested to demonstrate the effectiveness of the rePRAP model.

Effects of the DRG-based prospective payment system operated by the voluntarily participating providers on the cesarean section rates in Korea.

PubMed

Lee, Kwangsoo; Lee, Sangil

2007-05-01

This study explored the effects of the diagnosis-related group (DRG)-based prospective payment system (PPS) operated by voluntarily participating organizations on the cesarean section (CS) rates, and analyzed whether the participating health care organizations had similar CS rates despite the varied participation periods. The study sample included delivery claims data from the Korean national health insurance program for the year 2003. Risk factors were identified and used in the adjustment model to distinguish the main reason for CS. Their risk-adjusted CS rates were compared by the reimbursement methods, and the organizations' internal and external environments were controlled. The final risk-adjustment model for the CS rates meets the criteria for an effective model. There were no significant differences of CS rates between providers in the DRG and fee-for-service system after controlling for organizational variables. The CS rates did not vary significantly depending on the providers' DRG participation periods. The results provide evidence that the DRG payment system operated by volunteering health care organizations had no impact on the CS rates, which can lower the quality of care. Although the providers joined the DRG system in different years, there were no differences in the CS rates among the DRG providers. These results support the future expansion of the DRG-based PPS plan to all health care services in Korea.

Regression approaches in the test-negative study design for assessment of influenza vaccine effectiveness.

PubMed

Bond, H S; Sullivan, S G; Cowling, B J

2016-06-01

Influenza vaccination is the most practical means available for preventing influenza virus infection and is widely used in many countries. Because vaccine components and circulating strains frequently change, it is important to continually monitor vaccine effectiveness (VE). The test-negative design is frequently used to estimate VE. In this design, patients meeting the same clinical case definition are recruited and tested for influenza; those who test positive are the cases and those who test negative form the comparison group. When determining VE in these studies, the typical approach has been to use logistic regression, adjusting for potential confounders. Because vaccine coverage and influenza incidence change throughout the season, time is included among these confounders. While most studies use unconditional logistic regression, adjusting for time, an alternative approach is to use conditional logistic regression, matching on time. Here, we used simulation data to examine the potential for both regression approaches to permit accurate and robust estimates of VE. In situations where vaccine coverage changed during the influenza season, the conditional model and unconditional models adjusting for categorical week and using a spline function for week provided more accurate estimates. We illustrated the two approaches on data from a test-negative study of influenza VE against hospitalization in children in Hong Kong which resulted in the conditional logistic regression model providing the best fit to the data.

Evaluation of the DAVROS (Development And Validation of Risk-adjusted Outcomes for Systems of emergency care) risk-adjustment model as a quality indicator for healthcare

PubMed Central

Wilson, Richard; Goodacre, Steve W; Klingbajl, Marcin; Kelly, Anne-Maree; Rainer, Tim; Coats, Tim; Holloway, Vikki; Townend, Will; Crane, Steve

2014-01-01

Background and objective Risk-adjusted mortality rates can be used as a quality indicator if it is assumed that the discrepancy between predicted and actual mortality can be attributed to the quality of healthcare (ie, the model has attributional validity). The Development And Validation of Risk-adjusted Outcomes for Systems of emergency care (DAVROS) model predicts 7-day mortality in emergency medical admissions. We aimed to test this assumption by evaluating the attributional validity of the DAVROS risk-adjustment model. Methods We selected cases that had the greatest discrepancy between observed mortality and predicted probability of mortality from seven hospitals involved in validation of the DAVROS risk-adjustment model. Reviewers at each hospital assessed hospital records to determine whether the discrepancy between predicted and actual mortality could be explained by the healthcare provided. Results We received 232/280 (83%) completed review forms relating to 179 unexpected deaths and 53 unexpected survivors. The healthcare system was judged to have potentially contributed to 10/179 (8%) of the unexpected deaths and 26/53 (49%) of the unexpected survivors. Failure of the model to appropriately predict risk was judged to be responsible for 135/179 (75%) of the unexpected deaths and 2/53 (4%) of the unexpected survivors. Some 10/53 (19%) of the unexpected survivors died within a few months of the 7-day period of model prediction. Conclusions We found little evidence that deaths occurring in patients with a low predicted mortality from risk-adjustment could be attributed to the quality of healthcare provided. PMID:23605036

Development and testing of meteorology and air dispersion models for Mexico City

NASA Astrophysics Data System (ADS)

Williams, M. D.; Brown, M. J.; Cruz, X.; Sosa, G.; Streit, G.

Los Alamos National Laboratory and Instituto Mexicano del Petróleo are completing a joint study of options for improving air quality in Mexico City. We have modified a three-dimensional, prognostic, higher-order turbulence model for atmospheric circulation (HOTMAC) and a Monte Carlo dispersion and transport model (RAPTAD) to treat domains that include an urbanized area. We used the meteorological model to drive models which describe the photochemistry and air transport and dispersion. The photochemistry modeling is described in a separate paper. We tested the model against routine measurements and those of a major field program. During the field program, measurements included: (1) lidar measurements of aerosol transport and dispersion, (2) aircraft measurements of winds, turbulence, and chemical species aloft, (3) aircraft measurements of skin temperatures, and (4) Tethersonde measurements of winds and ozone. We modified the meteorological model to include provisions for time-varying synoptic-scale winds, adjustments for local wind effects, and detailed surface-coverage descriptions. We developed a new method to define mixing-layer heights based on model outputs. The meteorology and dispersion models were able to provide reasonable representations of the measurements and to define the sources of some of the major uncertainties in the model-measurement comparisons.

The Association between Parameters of Malnutrition and Diagnostic Measures of Sarcopenia in Geriatric Outpatients

PubMed Central

Reijnierse, Esmee M.; Trappenburg, Marijke C.; Leter, Morena J.; Blauw, Gerard Jan; de van der Schueren, Marian A. E.; Meskers, Carel G. M.; Maier, Andrea B.

2015-01-01

Objectives Diagnostic criteria for sarcopenia include measures of muscle mass, muscle strength and physical performance. Consensus on the definition of sarcopenia has not been reached yet. To improve insight into the most clinically valid definition of sarcopenia, this study aimed to compare the association between parameters of malnutrition, as a risk factor in sarcopenia, and diagnostic measures of sarcopenia in geriatric outpatients. Material and Methods This study is based on data from a cross-sectional study conducted in a geriatric outpatient clinic including 185 geriatric outpatients (mean age 82 years). Parameters of malnutrition included risk of malnutrition (assessed by the Short Nutritional Assessment Questionnaire), loss of appetite, unintentional weight loss and underweight (body mass index <22 kg/m2). Diagnostic measures of sarcopenia included relative muscle mass (lean mass and appendicular lean mass [ALM] as percentages), absolute muscle mass (total lean mass and ALM/height2), handgrip strength and walking speed. All diagnostic measures of sarcopenia were standardized. Associations between parameters of malnutrition (independent variables) and diagnostic measures of sarcopenia (dependent variables) were analysed using multivariate linear regression models adjusted for age, body mass, fat mass and height in separate models. Results None of the parameters of malnutrition was consistently associated with diagnostic measures of sarcopenia. The strongest associations were found for both relative and absolute muscle mass; less stronger associations were found for muscle strength and physical performance. Underweight (p = <0.001) and unintentional weight loss (p = 0.031) were most strongly associated with higher lean mass percentage after adjusting for age. Loss of appetite (p = 0.003) and underweight (p = 0.021) were most strongly associated with lower total lean mass after adjusting for age and fat mass. Conclusion Parameters of malnutrition relate differently to diagnostic measures of sarcopenia in geriatric outpatients. The association between parameters of malnutrition and diagnostic measures of sarcopenia was strongest for both relative and absolute muscle mass, while less strong associations were found with muscle strength and physical performance. PMID:26284368

Detection technology research on the one-way clutch of automatic brake adjuster

NASA Astrophysics Data System (ADS)

Jiang, Wensong; Luo, Zai; Lu, Yi

2013-10-01

In this article, we provide a new testing method to evaluate the acceptable quality of the one-way clutch of automatic brake adjuster. To analysis the suitable adjusting brake moment which keeps the automatic brake adjuster out of failure, we build a mechanical model of one-way clutch according to the structure and the working principle of one-way clutch. The ranges of adjusting brake moment both clockwise and anti-clockwise can be calculated through the mechanical model of one-way clutch. Its critical moment, as well, are picked up as the ideal values of adjusting brake moment to evaluate the acceptable quality of one-way clutch of automatic brake adjuster. we calculate the ideal values of critical moment depending on the different structure of one-way clutch based on its mechanical model before the adjusting brake moment test begin. In addition, an experimental apparatus, which the uncertainty of measurement is ±0.1Nm, is specially designed to test the adjusting brake moment both clockwise and anti-clockwise. Than we can judge the acceptable quality of one-way clutch of automatic brake adjuster by comparing the test results and the ideal values instead of the EXP. In fact, the evaluation standard of adjusting brake moment applied on the project are still using the EXP provided by manufacturer currently in China, but it would be unavailable when the material of one-way clutch changed. Five kinds of automatic brake adjusters are used in the verification experiment to verify the accuracy of the test method. The experimental results show that the experimental values of adjusting brake moment both clockwise and anti-clockwise are within the ranges of theoretical results. The testing method provided by this article vividly meet the requirements of manufacturer's standard.

Adjusting the Stems Regional Forest Growth Model to Improve Local Predictions

Treesearch

W. Brad Smith

1983-01-01

A simple procedure using double sampling is described for adjusting growth in the STEMS regional forest growth model to compensate for subregional variations. Predictive accuracy of the STEMS model (a distance-independent, individual tree growth model for Lake States forests) was improved by using this procedure

Fast food purchasing and access to fast food restaurants: a multilevel analysis of VicLANES

PubMed Central

Thornton, Lukar E; Bentley, Rebecca J; Kavanagh, Anne M

2009-01-01

Background While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES) – a cross-sectional multilevel study conducted within metropolitan Melbourne, Australia in 2003. Methods The VicLANES data used in this analysis included 2547 participants from 49 census collector districts in metropolitan Melbourne, Australia. The outcome of interest was the total frequency of fast food purchased for consumption at home within the previous month (never, monthly and weekly) from five major fast food chains (Red Rooster, McDonalds, Kentucky Fried Chicken, Hungry Jacks and Pizza Hut). Three measures of fast food access were created: density and variety, defined as the number of fast food restaurants and the number of different fast food chains within 3 kilometres of road network distance respectively, and proximity defined as the road network distance to the closest fast food restaurant. Multilevel multinomial models were used to estimate the associations between fast food restaurant access and purchasing with never purchased as the reference category. Models were adjusted for confounders including determinants of demand (attitudes and tastes that influence food purchasing decisions) as well as individual and area socio-economic characteristics. Results Purchasing fast food on a monthly basis was related to the variety of fast food restaurants (odds ratio 1.13; 95% confidence interval 1.02 – 1.25) after adjusting for individual and area characteristics. Density and proximity were not found to be significant predictors of fast food purchasing after adjustment for individual socio-economic predictors. Conclusion Although we found an independent association between fast food purchasing and access to a wider variety of fast food restaurant, density and proximity were not significant predictors. The methods used in our study are an advance on previous analyses. PMID:19473503

Accuracy Validation of Large-scale Block Adjustment without Control of ZY3 Images over China

NASA Astrophysics Data System (ADS)

Yang, Bo

2016-06-01

Mapping from optical satellite images without ground control is one of the goals of photogrammetry. Using 8802 three linear array stereo images (a total of 26406 images) of ZY3 over China, we propose a large-scale and non-control block adjustment method of optical satellite images based on the RPC model, in which a single image is regarded as an adjustment unit to be organized. To overcome the block distortion caused by unstable adjustment without ground control and the excessive accumulation of errors, we use virtual control points created by the initial RPC model of the images as the weighted observations and add them into the adjustment model to refine the adjustment. We use 8000 uniformly distributed high precision check points to evaluate the geometric accuracy of the DOM (Digital Ortho Model) and DSM (Digital Surface Model) production, for which the standard deviations of plane and elevation are 3.6 m and 4.2 m respectively. The geometric accuracy is consistent across the whole block and the mosaic accuracy of neighboring DOM is within a pixel, thus, the seamless mosaic could take place. This method achieves the goal of an accuracy of mapping without ground control better than 5 m for the whole China from ZY3 satellite images.

Simulation of climate characteristics and extremes of the Volta Basin using CCLM and RCA regional climate models

NASA Astrophysics Data System (ADS)

Darko, Deborah; Adjei, Kwaku A.; Appiah-Adjei, Emmanuel K.; Odai, Samuel N.; Obuobie, Emmanuel; Asmah, Ruby

2018-06-01

The extent to which statistical bias-adjusted outputs of two regional climate models alter the projected change signals for the mean (and extreme) rainfall and temperature over the Volta Basin is evaluated. The outputs from two regional climate models in the Coordinated Regional Climate Downscaling Experiment for Africa (CORDEX-Africa) are bias adjusted using the quantile mapping technique. Annual maxima rainfall and temperature with their 10- and 20-year return values for the present (1981-2010) and future (2051-2080) climates are estimated using extreme value analyses. Moderate extremes are evaluated using extreme indices (viz. percentile-based, duration-based, and intensity-based). Bias adjustment of the original (bias-unadjusted) models improves the reproduction of mean rainfall and temperature for the present climate. However, the bias-adjusted models poorly reproduce the 10- and 20-year return values for rainfall and maximum temperature whereas the extreme indices are reproduced satisfactorily for the present climate. Consequently, projected changes in rainfall and temperature extremes were weak. The bias adjustment results in the reduction of the change signals for the mean rainfall while the mean temperature signals are rather magnified. The projected changes for the original mean climate and extremes are not conserved after bias adjustment with the exception of duration-based extreme indices.

Should measures of patient experience in primary care be adjusted for case mix? Evidence from the English General Practice Patient Survey

PubMed Central

Paddison, Charlotte; Elliott, Marc; Parker, Richard; Staetsky, Laura; Lyratzopoulos, Georgios; Campbell, John L

2012-01-01

Objectives Uncertainties exist about when and how best to adjust performance measures for case mix. Our aims are to quantify the impact of case-mix adjustment on practice-level scores in a national survey of patient experience, to identify why and when it may be useful to adjust for case mix, and to discuss unresolved policy issues regarding the use of case-mix adjustment in performance measurement in health care. Design/setting Secondary analysis of the 2009 English General Practice Patient Survey. Responses from 2 163 456 patients registered with 8267 primary care practices. Linear mixed effects models were used with practice included as a random effect and five case-mix variables (gender, age, race/ethnicity, deprivation, and self-reported health) as fixed effects. Main outcome measures Primary outcome was the impact of case-mix adjustment on practice-level means (adjusted minus unadjusted) and changes in practice percentile ranks for questions measuring patient experience in three domains of primary care: access; interpersonal care; anticipatory care planning, and overall satisfaction with primary care services. Results Depending on the survey measure selected, case-mix adjustment changed the rank of between 0.4% and 29.8% of practices by more than 10 percentile points. Adjusting for case-mix resulted in large increases in score for a small number of practices and small decreases in score for a larger number of practices. Practices with younger patients, more ethnic minority patients and patients living in more socio-economically deprived areas were more likely to gain from case-mix adjustment. Age and race/ethnicity were the most influential adjustors. Conclusions While its effect is modest for most practices, case-mix adjustment corrects significant underestimation of scores for a small proportion of practices serving vulnerable patients and may reduce the risk that providers would ‘cream-skim’ by not enrolling patients from vulnerable socio-demographic groups. PMID:22626735

Should measures of patient experience in primary care be adjusted for case mix? Evidence from the English General Practice Patient Survey.

PubMed

Paddison, Charlotte; Elliott, Marc; Parker, Richard; Staetsky, Laura; Lyratzopoulos, Georgios; Campbell, John L; Roland, Martin

2012-08-01

Uncertainties exist about when and how best to adjust performance measures for case mix. Our aims are to quantify the impact of case-mix adjustment on practice-level scores in a national survey of patient experience, to identify why and when it may be useful to adjust for case mix, and to discuss unresolved policy issues regarding the use of case-mix adjustment in performance measurement in health care. Secondary analysis of the 2009 English General Practice Patient Survey. Responses from 2 163 456 patients registered with 8267 primary care practices. Linear mixed effects models were used with practice included as a random effect and five case-mix variables (gender, age, race/ethnicity, deprivation, and self-reported health) as fixed effects. Primary outcome was the impact of case-mix adjustment on practice-level means (adjusted minus unadjusted) and changes in practice percentile ranks for questions measuring patient experience in three domains of primary care: access; interpersonal care; anticipatory care planning, and overall satisfaction with primary care services. Depending on the survey measure selected, case-mix adjustment changed the rank of between 0.4% and 29.8% of practices by more than 10 percentile points. Adjusting for case-mix resulted in large increases in score for a small number of practices and small decreases in score for a larger number of practices. Practices with younger patients, more ethnic minority patients and patients living in more socio-economically deprived areas were more likely to gain from case-mix adjustment. Age and race/ethnicity were the most influential adjustors. While its effect is modest for most practices, case-mix adjustment corrects significant underestimation of scores for a small proportion of practices serving vulnerable patients and may reduce the risk that providers would 'cream-skim' by not enrolling patients from vulnerable socio-demographic groups.

The Galaxen model--a concept for rehabilitation and prevention in the construction industry.

PubMed

Stenlund, Berndt

2005-01-01

The Galaxen model was developed during the late 1980s to provide rehabilitation and prevention activities in the construction industry. It handles around 1200 workers with long-term sick leave or partial disabilities annually, some 10% of whom annually leave Galaxen for an ordinary job without a wage subsidy. The model includes a decision by a rehabilitation board of representatives from the employers, the trade union, and the regional employment office, a rehabilitation plan, allotment of a case manager, wage subsidies from the State to the company, a search for a suitable job in relation to the partial disability. It also includes a preventive program with emphasis on practical ergonomics. The Galaxen model has proved to be a suitable means of rehabilitating construction workers and returning them to the workforce. The model was developed within the Swedish social security system but could well be adjusted to other contexts.

Native American ancestry, lung function, and COPD in Costa Ricans.

PubMed

Chen, Wei; Brehm, John M; Boutaoui, Nadia; Soto-Quiros, Manuel; Avila, Lydiana; Celli, Bartolome R; Bruse, Shannon; Tesfaigzi, Yohannes; Celedón, Juan C

2014-04-01

Whether Native American ancestry (NAA) is associated with COPD or lung function in a racially admixed Hispanic population is unknown. We recruited 578 Costa Ricans with and without COPD into a hybrid case-control/family-based cohort, including 316 members of families of index case subjects. All participants completed questionnaires and spirometry and gave a blood sample for DNA extraction. Genome-wide genotyping was conducted with the Illumina Human610-Quad and HumanOmniExpress BeadChip kits (Illumina Inc), and individual ancestral proportions were estimated from these genotypic data and reference panels. For unrelated individuals, linear or logistic regression was used for the analysis of NAA and COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stage II or greater) or lung function. For extended families, linear mixed models and generalized estimating equations were used for the analysis. All models were adjusted for age, sex, educational level, and smoking behavior; models for FEV1 were also adjusted for height. The average proportion of European, Native American, and African ancestry among participants was 62%, 35%, and 3%, respectively. After adjustment for current smoking and other covariates, NAA was inversely associated with COPD (OR per 10% increment, 0.55; 95% CI, 0.41-0.75) but positively associated with FEV1, FVC, and FEV1/FVC. After additional adjustment for pack-years of smoking, the association between NAA and COPD or lung function measures was slightly attenuated. We found that about 31% of the estimated effect of NAA on COPD is mediated by pack-years of smoking. NAA is inversely associated with COPD but positively associated with FEV1 or FVC in Costa Ricans. Ancestral effects on smoking behavior partly explain the findings for COPD but not for FEV1 or FVC.

Native American Ancestry, Lung Function, and COPD in Costa Ricans

PubMed Central

Chen, Wei; Brehm, John M.; Boutaoui, Nadia; Soto-Quiros, Manuel; Avila, Lydiana; Celli, Bartolome R.; Bruse, Shannon; Tesfaigzi, Yohannes

2014-01-01

Background: Whether Native American ancestry (NAA) is associated with COPD or lung function in a racially admixed Hispanic population is unknown. Methods: We recruited 578 Costa Ricans with and without COPD into a hybrid case-control/family-based cohort, including 316 members of families of index case subjects. All participants completed questionnaires and spirometry and gave a blood sample for DNA extraction. Genome-wide genotyping was conducted with the Illumina Human610-Quad and HumanOmniExpress BeadChip kits (Illumina Inc), and individual ancestral proportions were estimated from these genotypic data and reference panels. For unrelated individuals, linear or logistic regression was used for the analysis of NAA and COPD (GOLD [Global Initiative for Chronic Obstructive Lung Disease] stage II or greater) or lung function. For extended families, linear mixed models and generalized estimating equations were used for the analysis. All models were adjusted for age, sex, educational level, and smoking behavior; models for FEV1 were also adjusted for height. Results: The average proportion of European, Native American, and African ancestry among participants was 62%, 35%, and 3%, respectively. After adjustment for current smoking and other covariates, NAA was inversely associated with COPD (OR per 10% increment, 0.55; 95% CI, 0.41-0.75) but positively associated with FEV1, FVC, and FEV1/FVC. After additional adjustment for pack-years of smoking, the association between NAA and COPD or lung function measures was slightly attenuated. We found that about 31% of the estimated effect of NAA on COPD is mediated by pack-years of smoking. Conclusions: NAA is inversely associated with COPD but positively associated with FEV1 or FVC in Costa Ricans. Ancestral effects on smoking behavior partly explain the findings for COPD but not for FEV1 or FVC. PMID:24306962

Early estimates of SEER cancer incidence, 2014.

PubMed

Lewis, Denise Riedel; Chen, Huann-Sheng; Cockburn, Myles G; Wu, Xiao-Cheng; Stroup, Antoinette M; Midthune, Douglas N; Zou, Zhaohui; Krapcho, Martin F; Miller, Daniel G; Feuer, Eric J

2017-07-01

Cancer incidence rates and trends for cases diagnosed through 2014 using data reported to the Surveillance, Epidemiology, and End Results (SEER) program in February 2016 and a validation of rates and trends for cases diagnosed through 2013 and submitted in February 2015 using the November 2015 submission are reported. New cancer sites include the pancreas, kidney and renal pelvis, corpus and uterus, and childhood cancer sites for ages birth to 19 years inclusive. A new reporting delay model is presented for these estimates for more consistent results with the model used for the usual November SEER submissions, adjusting for the large case undercount in the February submission. Joinpoint regression methodology was used to assess trends. Delay-adjusted rates and trends were checked for validity between the February 2016 and November 2016 submissions. Validation revealed that the delay model provides similar estimates of eventual counts using either February or November submission data. Trends declined through 2014 for prostate and colon and rectum cancer for males and females, male and female lung cancer, and cervical cancer. Thyroid cancer and liver and intrahepatic bile duct cancer increased. Pancreas (male and female) and corpus and uterus cancer demonstrated a modest increase. Slight increases occurred for male kidney and renal pelvis, and for all childhood cancer sites for ages birth to 19 years. Evaluating early cancer data submissions, adjusted for reporting delay, produces timely and valid incidence rates and trends. The results of the current study support using delay-adjusted February submission data for valid incidence rate and trend estimates over several data cycles. Cancer 2017;123:2524-34. © 2017 American Cancer Society. © 2017 American Cancer Society. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Food insecurity, food assistance and weight status in US youth: new evidence from NHANES 2007-08.

PubMed

Kohn, M J; Bell, J F; Grow, H M G; Chan, G

2014-04-01

To investigate food assistance participation as a risk factor for overweight and obesity in youth, and food insecurity as an effect modifier. The sample included youth ages 4-17, in families ≤200% of the federal poverty line in the 2007-2008 National Health and Nutrition Examination Survey (n = 1321). Food insecurity was measured with the US Department of Agriculture survey module. Food assistance participation was assessed for Supplemental Nutrition Assistance Program, Special Supplemental Nutrition Program for Women, Infants and Children and school meals. Body size was classified by age- and sex-specific body mass index (BMI) percentile, BMI z-score and waist circumference percentile. Regression models with direct covariate adjustment and programme-specific propensity scores, stratified by food insecurity, estimated associations between food assistance participation and body size. Food assistance participation was not associated with increased body size among food-insecure youth in models with direct covariate adjustment or propensity scores. Compared with low-income, food-secure youth not participating in food assistance, BMI z-scores were higher among participants in models with direct covariate adjustment (0.27-0.38 SD and 0.41-0.47 SD, for boys and girls, respectively). Using propensity scores, results were similar for boys, but less so for girls. Food assistance programme participation is associated with increased body size in food-secure youth, but not food-insecure youth. Using both direct covariate adjustment and a propensity score approach, self-selection bias may explain some, but not all, of the associations. Providing healthy food assistance that improves diet quality without contributing to excessive intake remains an important public health goal. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

Inpatient Consults and Complications During Primary Total Joint Arthroplasty in a Bundled Care Model.

PubMed

Baumgartner, Billy T; Karas, Vasili; Kildow, Beau J; Cunningham, Daniel J; Klement, Mitchell R; Green, Cindy L; Attarian, David E; Seyler, Thorsten M

2018-04-01

The Centers for Medicare and Medicaid Services (CMS) are implementing changes in hospital reimbursement models for total joint arthroplasty (TJA), moving to value-based bundled payments from the fee-for-service model. The purpose of this study is to identify consults and complications during the perioperative period that increase financial burden. We combined CMS payment data for inpatient, professional, and postoperative with retrospective review of patients undergoing primary TJA and developed profiles of patients included in the Comprehensive Care for Joint Replacement bundle undergoing TJA. Statistical comparison of episode inpatient events and payments was conducted. Multiple regression analysis was adjusted for length of stay, disposition, and Charlson-Deyo comorbidity profile. Median total payment was $21,577.36, which exceeded the median bundle target payment of $20,625.00. Adjusted analyses showed that psychiatry consults (increase of $73,123.32; P < .001), internal medicine consults ($5789.38; P ≤ .001), pulmonary embolism ($35,273.68; P < .001), intensive care unit admission ($14,078.37; P < .001), and deep vein thrombosis ($9471.26; P = .019) resulted in increased payments using multivariate analysis adjusted for length of stay, Charlson-Deyo comorbidities, and discharge disposition. Patients with inpatient complications such as pulmonary embolism and/or deep vein thrombosis, intensive care unit admission, and medical/psychiatric consultation exceeded the CMS target. Although study results showed typical complication rates, acute inpatient consultation significantly increased utilization beyond the CMS target even when adjusted for length of stay, patient comorbidities, and discharge. Needed medical care should continue to be a priority for inpatients, and allowance for individual outliers should be considered in policy discussions. Copyright © 2017 Elsevier Inc. All rights reserved.

Attribution of Extreme Rainfall Events in the South of France Using EURO-CORDEX Simulations

NASA Astrophysics Data System (ADS)

Luu, L. N.; Vautard, R.; Yiou, P.

2017-12-01

The Mediterranean region regularly undergoes episodes of intense precipitation in the fall season that exceed 300mm a day. This study focuses on the role of climate change on the dynamics of the events that occur in the South of France. We used an ensemble of 10 EURO-CORDEX model simulations with two horizontal resolutions (EUR-11: 0.11° and EUR-44: 0.44°) for the attribution of extreme rainfall in the fall in the Cevennes mountain range (South of France). The biases of the simulations were corrected with simple scaling adjustment and a quantile correction (CDFt). This produces five datasets including EUR-44 and EUR-11 with and without scaling adjustment and CDFt-EUR-11, on which we test the impact of resolution and bias correction on the extremes. Those datasets, after pooling all of models together, are fitted by a stationary Generalized Extreme Value distribution for several periods to estimate a climate change signal in the tail of distribution of extreme rainfall in the Cévenne region. Those changes are then interpreted by a scaling model that links extreme rainfall with mean and maximum daily temperature. The results show that higher-resolution simulations with bias adjustment provide a robust and confident increase of intensity and likelihood of occurrence of autumn extreme rainfall in the area in current climate in comparison with historical climate. The probability (exceedance probability) of 1-in-1000-year event in historical climate may increase by a factor of 1.8 under current climate with a confident interval of 0.4 to 5.3 following the CDFt bias-adjusted EUR-11. The change of magnitude appears to follow the Clausius-Clapeyron relation that indicates a 7% increase in rainfall per 1oC increase in temperature.

Is platelet transfusion associated with hospital-acquired infections in critically ill patients?

PubMed

Aubron, Cécile; Flint, Andrew W; Bailey, Michael; Pilcher, David; Cheng, Allen C; Hegarty, Colin; Martinelli, Antony; Reade, Michael C; Bellomo, Rinaldo; McQuilten, Zoe

2017-01-06

Platelets are commonly transfused to critically ill patients. Reports suggest an association between platelet transfusion and infection. However, there is no large study to have determined whether platelet transfusion in critically ill patients is associated with hospital-acquired infection. We conducted a multi-centre study using prospectively maintained databases of two large academic intensive care units (ICUs) in Australia. Characteristics of patients who received platelets in ICUs between 2008 and 2014 were compared to those of patients who did not receive platelets. Association between platelet administration and infection (bacteraemia and/or bacteriuria) was modelled using multiple logistic regression and Cox regression, with blood components as time-varying covariates. A propensity covariate adjustment was also performed to verify results. Of the 18,965 patients included, 2250 (11.9%) received platelets in ICU with a median number of 1 platelet unit (IQR 1-3) administered. Patients who received platelets were more severely ill at ICU admission (mean Acute Physiology and Chronic Health Evaluation III score 65 (SD 29) vs 52 (SD 25), p < 0.01) and had more comorbidities (31% vs 19%, p < 0.01) than patients without platelet transfusion. Invasive mechanical ventilation (87% vs 57%, p < 0.01) and renal replacement therapy (20% vs 4%, p < 0.01) were more frequently administered in patients receiving platelets than in patients without platelets. On univariate analysis, platelet transfusion was associated with hospital-acquired infection in the ICU (7.7% vs 1.4%, p < 0.01). After adjusting for confounders, including other blood components administered, patient severity, centre, year, and diagnosis category, platelet transfusions were independently associated with infection (adjusted OR 2.56 95% CI 1.98-3.31, p < 0.001). This association was also found in survival analysis with blood components as time-varying covariates (adjusted HR 1.85, 95% CI 1.41-2.41, p < 0.001) and when only bacteraemia was considered (adjusted OR 3.30, 95% CI 2.30-4.74, p <0.001). Platelet transfusions remained associated with infection after propensity covariate adjustment. After adjustment for confounders, including patient severity and other blood components, platelet transfusion was independently associated with ICU-acquired infection. Further research aiming to better understand this association and to prevent this complication is warranted.

Development and Validation of Perioperative Risk-Adjustment Models for Hip Fracture Repair, Total Hip Arthroplasty, and Total Knee Arthroplasty.

PubMed

Schilling, Peter L; Bozic, Kevin J

2016-01-06

Comparing outcomes across providers requires risk-adjustment models that account for differences in case mix. The burden of data collection from the clinical record can make risk-adjusted outcomes difficult to measure. The purpose of this study was to develop risk-adjustment models for hip fracture repair (HFR), total hip arthroplasty (THA), and total knee arthroplasty (TKA) that weigh adequacy of risk adjustment against data-collection burden. We used data from the American College of Surgeons National Surgical Quality Improvement Program to create derivation cohorts for HFR (n = 7000), THA (n = 17,336), and TKA (n = 28,661). We developed logistic regression models for each procedure using age, sex, American Society of Anesthesiologists (ASA) physical status classification, comorbidities, laboratory values, and vital signs-based comorbidities as covariates, and validated the models with use of data from 2012. The derivation models' C-statistics for mortality were 80%, 81%, 75%, and 92% and for adverse events were 68%, 68%, 60%, and 70% for HFR, THA, TKA, and combined procedure cohorts. Age, sex, and ASA classification accounted for a large share of the explained variation in mortality (50%, 58%, 70%, and 67%) and adverse events (43%, 45%, 46%, and 68%). For THA and TKA, these three variables were nearly as predictive as models utilizing all covariates. HFR model discrimination improved with the addition of comorbidities and laboratory values; among the important covariates were functional status, low albumin, high creatinine, disseminated cancer, dyspnea, and body mass index. Model performance was similar in validation cohorts. Risk-adjustment models using data from health records demonstrated good discrimination and calibration for HFR, THA, and TKA. It is possible to provide adequate risk adjustment using only the most predictive variables commonly available within the clinical record. This finding helps to inform the trade-off between model performance and data-collection burden as well as the need to define priorities for data capture from electronic health records. These models can be used to make fair comparisons of outcome measures intended to characterize provider quality of care for value-based-purchasing and registry initiatives. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

A Comparison of the Performance of Advanced Statistical Techniques for the Refinement of Day-ahead and Longer NWP-based Wind Power Forecasts

NASA Astrophysics Data System (ADS)

Zack, J. W.

2015-12-01

Predictions from Numerical Weather Prediction (NWP) models are the foundation for wind power forecasts for day-ahead and longer forecast horizons. The NWP models directly produce three-dimensional wind forecasts on their respective computational grids. These can be interpolated to the location and time of interest. However, these direct predictions typically contain significant systematic errors ("biases"). This is due to a variety of factors including the limited space-time resolution of the NWP models and shortcomings in the model's representation of physical processes. It has become common practice to attempt to improve the raw NWP forecasts by statistically adjusting them through a procedure that is widely known as Model Output Statistics (MOS). The challenge is to identify complex patterns of systematic errors and then use this knowledge to adjust the NWP predictions. The MOS-based improvements are the basis for much of the value added by commercial wind power forecast providers. There are an enormous number of statistical approaches that can be used to generate the MOS adjustments to the raw NWP forecasts. In order to obtain insight into the potential value of some of the newer and more sophisticated statistical techniques often referred to as "machine learning methods" a MOS-method comparison experiment has been performed for wind power generation facilities in 6 wind resource areas of California. The underlying NWP models that provided the raw forecasts were the two primary operational models of the US National Weather Service: the GFS and NAM models. The focus was on 1- and 2-day ahead forecasts of the hourly wind-based generation. The statistical methods evaluated included: (1) screening multiple linear regression, which served as a baseline method, (2) artificial neural networks, (3) a decision-tree approach called random forests, (4) gradient boosted regression based upon an decision-tree algorithm, (5) support vector regression and (6) analog ensemble, which is a case-matching scheme. The presentation will provide (1) an overview of each method and the experimental design, (2) performance comparisons based on standard metrics such as bias, MAE and RMSE, (3) a summary of the performance characteristics of each approach and (4) a preview of further experiments to be conducted.

Nonlinear predictive control for adaptive adjustments of deep brain stimulation parameters in basal ganglia-thalamic network.

PubMed

Su, Fei; Wang, Jiang; Niu, Shuangxia; Li, Huiyan; Deng, Bin; Liu, Chen; Wei, Xile

2018-02-01

The efficacy of deep brain stimulation (DBS) for Parkinson's disease (PD) depends in part on the post-operative programming of stimulation parameters. Closed-loop stimulation is one method to realize the frequent adjustment of stimulation parameters. This paper introduced the nonlinear predictive control method into the online adjustment of DBS amplitude and frequency. This approach was tested in a computational model of basal ganglia-thalamic network. The autoregressive Volterra model was used to identify the process model based on physiological data. Simulation results illustrated the efficiency of closed-loop stimulation methods (amplitude adjustment and frequency adjustment) in improving the relay reliability of thalamic neurons compared with the PD state. Besides, compared with the 130Hz constant DBS the closed-loop stimulation methods can significantly reduce the energy consumption. Through the analysis of inter-spike-intervals (ISIs) distribution of basal ganglia neurons, the evoked network activity by the closed-loop frequency adjustment stimulation was closer to the normal state. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adjusted variable plots for Cox's proportional hazards regression model.

PubMed

Hall, C B; Zeger, S L; Bandeen-Roche, K J

1996-01-01

Adjusted variable plots are useful in linear regression for outlier detection and for qualitative evaluation of the fit of a model. In this paper, we extend adjusted variable plots to Cox's proportional hazards model for possibly censored survival data. We propose three different plots: a risk level adjusted variable (RLAV) plot in which each observation in each risk set appears, a subject level adjusted variable (SLAV) plot in which each subject is represented by one point, and an event level adjusted variable (ELAV) plot in which the entire risk set at each failure event is represented by a single point. The latter two plots are derived from the RLAV by combining multiple points. In each point, the regression coefficient and standard error from a Cox proportional hazards regression is obtained by a simple linear regression through the origin fit to the coordinates of the pictured points. The plots are illustrated with a reanalysis of a dataset of 65 patients with multiple myeloma.

Alternatives for using multivariate regression to adjust prospective payment rates

PubMed Central

Sheingold, Steven H.

1990-01-01

Multivariate regression analysis has been used in structuring three of the adjustments to Medicare's prospective payment rates. Because the indirect-teaching adjustment, the disproportionate-share adjustment, and the adjustment for large cities are responsible for distributing approximately $3 billion in payments each year, the specification of regression models for these adjustments is of critical importance. In this article, the application of regression for adjusting Medicare's prospective rates is discussed, and the implications that differing specifications could have for these adjustments are demonstrated. PMID:10113271