Comparative Study of Multimodal Biometric Recognition by Fusion of Iris and Fingerprint

PubMed Central

Benaliouche, Houda; Touahria, Mohamed

2014-01-01

This research investigates the comparative performance from three different approaches for multimodal recognition of combined iris and fingerprints: classical sum rule, weighted sum rule, and fuzzy logic method. The scores from the different biometric traits of iris and fingerprint are fused at the matching score and the decision levels. The scores combination approach is used after normalization of both scores using the min-max rule. Our experimental results suggest that the fuzzy logic method for the matching scores combinations at the decision level is the best followed by the classical weighted sum rule and the classical sum rule in order. The performance evaluation of each method is reported in terms of matching time, error rates, and accuracy after doing exhaustive tests on the public CASIA-Iris databases V1 and V2 and the FVC 2004 fingerprint database. Experimental results prior to fusion and after fusion are presented followed by their comparison with related works in the current literature. The fusion by fuzzy logic decision mimics the human reasoning in a soft and simple way and gives enhanced results. PMID:24605065

Propensity Score Matching within Prognostic Strata

ERIC Educational Resources Information Center

Kelcey, Ben

2013-01-01

A central issue in nonexperimental studies is identifying comparable individuals to remove selection bias. One common way to address this selection bias is through propensity score (PS) matching. PS methods use a model of the treatment assignment to reduce the dimensionality of the covariate space and identify comparable individuals. parallel to…

The performance of different propensity score methods for estimating absolute effects of treatments on survival outcomes: A simulation study.

PubMed

Austin, Peter C; Schuster, Tibor

2016-10-01

Observational studies are increasingly being used to estimate the effect of treatments, interventions and exposures on outcomes that can occur over time. Historically, the hazard ratio, which is a relative measure of effect, has been reported. However, medical decision making is best informed when both relative and absolute measures of effect are reported. When outcomes are time-to-event in nature, the effect of treatment can also be quantified as the change in mean or median survival time due to treatment and the absolute reduction in the probability of the occurrence of an event within a specified duration of follow-up. We describe how three different propensity score methods, propensity score matching, stratification on the propensity score and inverse probability of treatment weighting using the propensity score, can be used to estimate absolute measures of treatment effect on survival outcomes. These methods are all based on estimating marginal survival functions under treatment and lack of treatment. We then conducted an extensive series of Monte Carlo simulations to compare the relative performance of these methods for estimating the absolute effects of treatment on survival outcomes. We found that stratification on the propensity score resulted in the greatest bias. Caliper matching on the propensity score and a method based on earlier work by Cole and Hernán tended to have the best performance for estimating absolute effects of treatment on survival outcomes. When the prevalence of treatment was less extreme, then inverse probability of treatment weighting-based methods tended to perform better than matching-based methods. © The Author(s) 2014.

An Assessment of Propensity Score Matching as a Nonexperimental Impact Estimator: Evidence from Mexico's PROGRESA Program

ERIC Educational Resources Information Center

Diaz, Juan Jose; Handa, Sudhanshu

2006-01-01

Not all policy questions can be addressed by social experiments. Nonexperimental evaluation methods provide an alternative to experimental designs but their results depend on untestable assumptions. This paper presents evidence on the reliability of propensity score matching (PSM), which estimates treatment effects under the assumption of…

Computing quality scores and uncertainty for approximate pattern matching in geospatial semantic graphs

DOE PAGES

Stracuzzi, David John; Brost, Randolph C.; Phillips, Cynthia A.; ...

2015-09-26

Geospatial semantic graphs provide a robust foundation for representing and analyzing remote sensor data. In particular, they support a variety of pattern search operations that capture the spatial and temporal relationships among the objects and events in the data. However, in the presence of large data corpora, even a carefully constructed search query may return a large number of unintended matches. This work considers the problem of calculating a quality score for each match to the query, given that the underlying data are uncertain. As a result, we present a preliminary evaluation of three methods for determining both match qualitymore » scores and associated uncertainty bounds, illustrated in the context of an example based on overhead imagery data.« less

Statistical primer: propensity score matching and its alternatives.

PubMed

Benedetto, Umberto; Head, Stuart J; Angelini, Gianni D; Blackstone, Eugene H

2018-06-01

Propensity score (PS) methods offer certain advantages over more traditional regression methods to control for confounding by indication in observational studies. Although multivariable regression models adjust for confounders by modelling the relationship between covariates and outcome, the PS methods estimate the treatment effect by modelling the relationship between confounders and treatment assignment. Therefore, methods based on the PS are not limited by the number of events, and their use may be warranted when the number of confounders is large, or the number of outcomes is small. The PS is the probability for a subject to receive a treatment conditional on a set of baseline characteristics (confounders). The PS is commonly estimated using logistic regression, and it is used to match patients with similar distribution of confounders so that difference in outcomes gives unbiased estimate of treatment effect. This review summarizes basic concepts of the PS matching and provides guidance in implementing matching and other methods based on the PS, such as stratification, weighting and covariate adjustment.

Examining Moderation Analyses in Propensity Score Methods: Application to Depression and Substance Use

PubMed Central

Green, Kerry M.; Stuart, Elizabeth A.

2014-01-01

Objective This study provides guidance on how propensity score methods can be combined with moderation analyses (i.e., effect modification) to examine subgroup differences in potential causal effects in non-experimental studies. As a motivating example, we focus on how depression may affect subsequent substance use differently for men and women. Method Using data from a longitudinal community cohort study (N=952) of urban African Americans with assessments in childhood, adolescence, young adulthood and midlife, we estimate the influence of depression by young adulthood on substance use outcomes in midlife, and whether that influence varies by gender. We illustrate and compare five different techniques for estimating subgroup effects using propensity score methods, including separate propensity score models and matching for men and women, a joint propensity score model for men and women with matching separately and together by gender, and a joint male/female propensity score model that includes theoretically important gender interactions with matching separately and together by gender. Results Analyses showed that estimating separate models for men and women yielded the best balance and, therefore, is a preferred technique when subgroup analyses are of interest, at least in this data. Results also showed substance use consequences of depression but no significant gender differences. Conclusions It is critical to prespecify subgroup effects before the estimation of propensity scores and to check balance within subgroups regardless of the type of propensity score model used. Results also suggest that depression may affect multiple substance use outcomes in midlife for both men and women relatively equally. PMID:24731233

It's all about balance: propensity score matching in the context of complex survey data.

PubMed

Lenis, David; Nguyen, Trang Quynh; Dong, Nianbo; Stuart, Elizabeth A

2017-12-27

Many research studies aim to draw causal inferences using data from large, nationally representative survey samples, and many of these studies use propensity score matching to make those causal inferences as rigorous as possible given the non-experimental nature of the data. However, very few applied studies are careful about incorporating the survey design with the propensity score analysis, which may mean that the results do not generate population inferences. This may be because few methodological studies examine how to best combine these methods. Furthermore, even fewer of them investigate different non-response mechanisms. This study examines methods for handling survey weights in propensity score matching analyses of survey data under different non-response mechanisms. Our main conclusions are: (i) whether the survey weights are incorporated in the estimation of the propensity score does not impact estimation of the population treatment effect, as long as good population treated-comparison balance is achieved on confounders, (ii) survey weights must be used in the outcome analysis, and (iii) the transferring of survey weights (i.e., assigning the weights of the treated units to the comparison units matched to them) can be beneficial under certain non-response mechanisms. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A new plan-scoring method using normal tissue complication probability for personalized treatment plan decisions in prostate cancer

NASA Astrophysics Data System (ADS)

Kim, Kwang Hyeon; Lee, Suk; Shim, Jang Bo; Yang, Dae Sik; Yoon, Won Sup; Park, Young Je; Kim, Chul Yong; Cao, Yuan Jie; Chang, Kyung Hwan

2018-01-01

The aim of this study was to derive a new plan-scoring index using normal tissue complication probabilities to verify different plans in the selection of personalized treatment. Plans for 12 patients treated with tomotherapy were used to compare scoring for ranking. Dosimetric and biological indexes were analyzed for the plans for a clearly distinguishable group ( n = 7) and a similar group ( n = 12), using treatment plan verification software that we developed. The quality factor ( QF) of our support software for treatment decisions was consistent with the final treatment plan for the clearly distinguishable group (average QF = 1.202, 100% match rate, n = 7) and the similar group (average QF = 1.058, 33% match rate, n = 12). Therefore, we propose a normal tissue complication probability (NTCP) based on the plan scoring index for verification of different plans for personalized treatment-plan selection. Scoring using the new QF showed a 100% match rate (average NTCP QF = 1.0420). The NTCP-based new QF scoring method was adequate for obtaining biological verification quality and organ risk saving using the treatment-planning decision-support software we developed for prostate cancer.

Myopia and cognitive dysfunction among elderly Chinese adults: a propensity score matching analysis.

PubMed

Sun, Hong-Peng; Liu, Hu; Xu, Yong; Pan, Chen-Wei

2016-03-01

The association between myopia and cognitive dysfunction among elderly adults was assessed by applying a Propensity Score Matching (PSM) approach. This is a statistical method which allows investigators to estimate causal treatment effects using observational or nonrandomised data. The study was designed as a community-based cross-sectional study based on a Chinese cohort aged 60 years or older in China. Objective refraction was measured using an autorefractor and subjective refraction was used to refine vision, using the results of the objective refraction as the starting point. Myopia was defined as a spherical equivalent value of less than -0.50 dioptre (D) in the right eye. The Abbreviated Mental Test (AMT) was used for cognitive assessment. The propensity scores for myopia were formulated using 13 potential confounders. We matched the propensity scores for subjects with and without myopia within a caliper of 0.01 of logit function of propensity scores. About 4123 elderly adults who successfully completed the AMT were included in this analysis. The odds ratio (OR) of cognitive dysfunction for myopia before matching was 1.98 (95% confidence interval [CI] 1.61, 2.44; p < 0.001). There were significant covariate imbalances between comparison groups and after propensity score matching, covariate imbalance was significantly reduced. After propensity score matching, the OR of cognitive dysfunction was marginally significant and the magnitude of association was reduced (OR: 1.31 95% CI 1.00, 1.71; p = 0.05). Traditional multivariate logistic regression modelling found an OR of 1.52 (95% CI 1.23, 2.06; p < 0.001) after adjusting for the 13 potential confounders. Myopia was associated with a higher prevalence of cognitive dysfunction among elderly Chinese aged 60 years or older in China. The PSM approach may be a useful method to address selection bias in observational studies when randomised trials cannot ethically be conducted. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

Matching methods evaluation framework for stereoscopic breast x-ray images.

PubMed

Rousson, Johanna; Naudin, Mathieu; Marchessoux, Cédric

2016-01-01

Three-dimensional (3-D) imaging has been intensively studied in the past few decades. Depth information is an important added value of 3-D systems over two-dimensional systems. Special focuses were devoted to the development of stereo matching methods for the generation of disparity maps (i.e., depth information within a 3-D scene). Dedicated frameworks were designed to evaluate and rank the performance of different stereo matching methods but never considering x-ray medical images. Yet, 3-D x-ray acquisition systems and 3-D medical displays have already been introduced into the diagnostic market. To access the depth information within x-ray stereoscopic images, computing accurate disparity maps is essential. We aimed at developing a framework dedicated to x-ray stereoscopic breast images used to evaluate and rank several stereo matching methods. A multiresolution pyramid optimization approach was integrated to the framework to increase the accuracy and the efficiency of the stereo matching techniques. Finally, a metric was designed to score the results of the stereo matching compared with the ground truth. Eight methods were evaluated and four of them [locally scaled sum of absolute differences (LSAD), zero mean sum of absolute differences, zero mean sum of squared differences, and locally scaled mean sum of squared differences] appeared to perform equally good with an average error score of 0.04 (0 is the perfect matching). LSAD was selected for generating the disparity maps.

Matching on the Disease Risk Score in Comparative Effectiveness Research of New Treatments

PubMed Central

Wyss, Richard; Ellis, Alan R.; Brookhart, M. Alan; Funk, Michele Jonsson; Girman, Cynthia J.; Simpson, Ross J.; Stürmer, Til

2016-01-01

Purpose We use simulations and an empirical example to evaluate the performance of disease risk score (DRS) matching compared with propensity score (PS) matching when controlling large numbers of covariates in settings involving newly introduced treatments. Methods We simulated a dichotomous treatment, a dichotomous outcome, and 100 baseline covariates that included both continuous and dichotomous random variables. For the empirical example, we evaluated the comparative effectiveness of dabigatran versus warfarin in preventing combined ischemic stroke and all-cause mortality. We matched treatment groups on a historically estimated DRS and again on the PS. We controlled for a high-dimensional set of covariates using 20% and 1% samples of Medicare claims data from October 2010 through December 2012. Results In simulations, matching on the DRS versus the PS generally yielded matches for more treated individuals and improved precision of the effect estimate. For the empirical example, PS and DRS matching in the 20% sample resulted in similar hazard ratios (0.88 and 0.87) and standard errors (0.04 for both methods). In the 1% sample, PS matching resulted in matches for only 92.0% of the treated population and a hazard ratio and standard error of 0.89 and 0.19, respectively, while DRS matching resulted in matches for 98.5% and a hazard ratio and standard error of 0.85 and 0.16, respectively. Conclusions When PS distributions are separated, DRS matching can improve the precision of effect estimates and allow researchers to evaluate the treatment effect in a larger proportion of the treated population. However, accurately modeling the DRS can be challenging compared with the PS. PMID:26112690

Mobile Visual Search Based on Histogram Matching and Zone Weight Learning

NASA Astrophysics Data System (ADS)

Zhu, Chuang; Tao, Li; Yang, Fan; Lu, Tao; Jia, Huizhu; Xie, Xiaodong

2018-01-01

In this paper, we propose a novel image retrieval algorithm for mobile visual search. At first, a short visual codebook is generated based on the descriptor database to represent the statistical information of the dataset. Then, an accurate local descriptor similarity score is computed by merging the tf-idf weighted histogram matching and the weighting strategy in compact descriptors for visual search (CDVS). At last, both the global descriptor matching score and the local descriptor similarity score are summed up to rerank the retrieval results according to the learned zone weights. The results show that the proposed approach outperforms the state-of-the-art image retrieval method in CDVS.

A social network analysis of the goal scoring passing networks of the 2016 European Football Championships.

PubMed

Mclean, Scott; Salmon, Paul M; Gorman, Adam D; Stevens, Nicholas J; Solomon, Colin

2018-02-01

In the current study, social network analysis (SNA) and notational analysis (NA) methods were applied to examine the goal scoring passing networks (GSPN) for all goals scored at the 2016 European Football Championships. The aim of the study was to determine the GSPN characteristics for the overall tournament, between the group and knock out stages, and for the successful and unsuccessful teams. The study also used degree centrality (DC) metrics as a novel method to determine the relative contributions of the pitch locations involved in the GSPN. To determine changes in GSPN characteristics as a function of changing score line, the analysis considered the match status of the game when goals were scored. There were significant differences for SNA metrics as a function of match status, and for the DC metrics in the comparison of the different pitch locations. There were no differences in the SNA metrics for the GSPN between teams in the group and knock out stages, or between the successful and unsuccessful teams. The results indicate that the GSPN had low values for network density, cohesion, connections, and duration. The networks were direct in terms of pitch zones utilised, where 85% of the GSPN included passes that were played within zones or progressed through the zones towards the goal. SNA and NA metrics were significantly different as a function of changing match status. The current study adds to the previous research on goal scoring in football, and demonstrates a novel method to determine the prominent pitch zones involved in the GSPN. These results have implications for match analysis and the coaching process. Copyright © 2017 Elsevier B.V. All rights reserved.

Understanding Foster Youth Outcomes: Is Propensity Scoring Better than Traditional Methods?

ERIC Educational Resources Information Center

Berzin, Stephanie Cosner

2010-01-01

Objectives: This study seeks to examine the relationship between foster care and outcomes using multiple comparison methods to account for factors that put foster youth at risk independent of care. Methods: Using the National Longitudinal Survey of Youth 1997, matching, propensity scoring, and comparisons to the general population are used to…

Propensity score method: a non-parametric technique to reduce model dependence

PubMed Central

2017-01-01

Propensity score analysis (PSA) is a powerful technique that it balances pretreatment covariates, making the causal effect inference from observational data as reliable as possible. The use of PSA in medical literature has increased exponentially in recent years, and the trend continue to rise. The article introduces rationales behind PSA, followed by illustrating how to perform PSA in R with MatchIt package. There are a variety of methods available for PS matching such as nearest neighbors, full matching, exact matching and genetic matching. The task can be easily done by simply assigning a string value to the method argument in the matchit() function. The generic summary() and plot() functions can be applied to an object of class matchit to check covariate balance after matching. Furthermore, there is a useful package PSAgraphics that contains several graphical functions to check covariate balance between treatment groups across strata. If covariate balance is not achieved, one can modify model specifications or use other techniques such as random forest and recursive partitioning to better represent the underlying structure between pretreatment covariates and treatment assignment. The process can be repeated until the desirable covariate balance is achieved. PMID:28164092

Assessing the Impact of School-Based Health Centers on Academic Achievement and College Preparation Efforts: Using Propensity Score Matching to Assess School-Level Data in California

ERIC Educational Resources Information Center

Bersamin, Melina; Garbers, Samantha; Gaarde, Jenna; Santelli, John

2016-01-01

This study examines the association between school-based health center (SBHC) presence and school-wide measures of academic achievement and college preparation efforts. Publicly available educational and demographic data from 810 California public high schools were linked to a list of schools with an SBHC. Propensity score matching, a method to…

A multistage gene normalization system integrating multiple effective methods.

PubMed

Li, Lishuang; Liu, Shanshan; Li, Lihua; Fan, Wenting; Huang, Degen; Zhou, Huiwei

2013-01-01

Gene/protein recognition and normalization is an important preliminary step for many biological text mining tasks. In this paper, we present a multistage gene normalization system which consists of four major subtasks: pre-processing, dictionary matching, ambiguity resolution and filtering. For the first subtask, we apply the gene mention tagger developed in our earlier work, which achieves an F-score of 88.42% on the BioCreative II GM testing set. In the stage of dictionary matching, the exact matching and approximate matching between gene names and the EntrezGene lexicon have been combined. For the ambiguity resolution subtask, we propose a semantic similarity disambiguation method based on Munkres' Assignment Algorithm. At the last step, a filter based on Wikipedia has been built to remove the false positives. Experimental results show that the presented system can achieve an F-score of 90.1%, outperforming most of the state-of-the-art systems.

Graphic report of the results from propensity score method analyses.

PubMed

Shrier, Ian; Pang, Menglan; Platt, Robert W

2017-08-01

To increase transparency in studies reporting propensity scores by using graphical methods that clearly illustrate (1) the number of participant exclusions that occur as a consequence of the analytic strategy and (2) whether treatment effects are constant or heterogeneous across propensity scores. We applied graphical methods to a real-world pharmacoepidemiologic study that evaluated the effect of initiating statin medication on the 1-year all-cause mortality post-myocardial infarction. We propose graphical methods to show the consequences of trimming and matching on the exclusion of participants from the analysis. We also propose the use of meta-analytical forest plots to show the magnitude of effect heterogeneity. A density plot with vertical lines demonstrated the proportion of subjects excluded because of trimming. A frequency plot with horizontal lines demonstrated the proportion of subjects excluded because of matching. An augmented forest plot illustrates the amount of effect heterogeneity present in the data. Our proposed techniques present additional and useful information that helps readers understand the sample that is analyzed with propensity score methods and whether effect heterogeneity is present. Copyright © 2017 Elsevier Inc. All rights reserved.

Multilevel Propensity Score Matching within and across Schools

ERIC Educational Resources Information Center

Kelcey, Benjamin

2011-01-01

A central issue in nonexperimental studies is the identification of comparable individuals (e.g. students) to remove selection bias. One such increasingly common method to identify comparable individuals and address selection bias is the propensity score (PS). PS methods rely on a model of the treatment assignment to identify comparable…

[Propensity score matching in SPSS].

PubMed

Huang, Fuqiang; DU, Chunlin; Sun, Menghui; Ning, Bing; Luo, Ying; An, Shengli

2015-11-01

To realize propensity score matching in PS Matching module of SPSS and interpret the analysis results. The R software and plug-in that could link with the corresponding versions of SPSS and propensity score matching package were installed. A PS matching module was added in the SPSS interface, and its use was demonstrated with test data. Score estimation and nearest neighbor matching was achieved with the PS matching module, and the results of qualitative and quantitative statistical description and evaluation were presented in the form of a graph matching. Propensity score matching can be accomplished conveniently using SPSS software.

Personal authentication using hand vein triangulation and knuckle shape.

PubMed

Kumar, Ajay; Prathyusha, K Venkata

2009-09-01

This paper presents a new approach to authenticate individuals using triangulation of hand vein images and simultaneous extraction of knuckle shape information. The proposed method is fully automated and employs palm dorsal hand vein images acquired from the low-cost, near infrared, contactless imaging. The knuckle tips are used as key points for the image normalization and extraction of region of interest. The matching scores are generated in two parallel stages: (i) hierarchical matching score from the four topologies of triangulation in the binarized vein structures and (ii) from the geometrical features consisting of knuckle point perimeter distances in the acquired images. The weighted score level combination from these two matching scores are used to authenticate the individuals. The achieved experimental results from the proposed system using contactless palm dorsal-hand vein images are promising (equal error rate of 1.14%) and suggest more user friendly alternative for user identification.

Spot the match – wildlife photo-identification using information theory

PubMed Central

Speed, Conrad W; Meekan, Mark G; Bradshaw, Corey JA

2007-01-01

Background Effective approaches for the management and conservation of wildlife populations require a sound knowledge of population demographics, and this is often only possible through mark-recapture studies. We applied an automated spot-recognition program (I3S) for matching natural markings of wildlife that is based on a novel information-theoretic approach to incorporate matching uncertainty. Using a photo-identification database of whale sharks (Rhincodon typus) as an example case, the information criterion (IC) algorithm we developed resulted in a parsimonious ranking of potential matches of individuals in an image library. Automated matches were compared to manual-matching results to test the performance of the software and algorithm. Results Validation of matched and non-matched images provided a threshold IC weight (approximately 0.2) below which match certainty was not assured. Most images tested were assigned correctly; however, scores for the by-eye comparison were lower than expected, possibly due to the low sample size. The effect of increasing horizontal angle of sharks in images reduced matching likelihood considerably. There was a negative linear relationship between the number of matching spot pairs and matching score, but this relationship disappeared when using the IC algorithm. Conclusion The software and use of easily applied information-theoretic scores of match parsimony provide a reliable and freely available method for individual identification of wildlife, with wide applications and the potential to improve mark-recapture studies without resorting to invasive marking techniques. PMID:17227581

D-score: a search engine independent MD-score.

PubMed

Vaudel, Marc; Breiter, Daniela; Beck, Florian; Rahnenführer, Jörg; Martens, Lennart; Zahedi, René P

2013-03-01

While peptides carrying PTMs are routinely identified in gel-free MS, the localization of the PTMs onto the peptide sequences remains challenging. Search engine scores of secondary peptide matches have been used in different approaches in order to infer the quality of site inference, by penalizing the localization whenever the search engine similarly scored two candidate peptides with different site assignments. In the present work, we show how the estimation of posterior error probabilities for peptide candidates allows the estimation of a PTM score called the D-score, for multiple search engine studies. We demonstrate the applicability of this score to three popular search engines: Mascot, OMSSA, and X!Tandem, and evaluate its performance using an already published high resolution data set of synthetic phosphopeptides. For those peptides with phosphorylation site inference uncertainty, the number of spectrum matches with correctly localized phosphorylation increased by up to 25.7% when compared to using Mascot alone, although the actual increase depended on the fragmentation method used. Since this method relies only on search engine scores, it can be readily applied to the scoring of the localization of virtually any modification at no additional experimental or in silico cost. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Association between long work hours and depressive state: a pilot study of propensity score matched Japanese white-collar workers.

PubMed

Uchida, Mitsuo; Morita, Hiroshi

2018-06-01

Although long work hours have been associated with various physical health problems, studies of their association with mental health have yielded inconsistent results, due to differences in study settings, study outcome and/or unmeasured background factors. In this study, we used a propensity score method to evaluate the association between work hours and depressive state. A total of 467 Japanese white-collar workers were surveyed and divided into long and regular work hour groups according to overtime work records. Propensity score matching was performed based on 32 individual background and workplace factors, yielding 74 pairs of propensity-matched subjects. CES-D score, an indicator of depressive state, did not differ significantly among the two groups (p=0.203). However, work motivation, work control, social support and emotional stability correlated with CES-D score. These findings suggest that work control and social support factors are more associated with depressive state than control of work hours. These results also suggest that it is possible to use propensity score matching to evaluate the association between work hours and mental health in occupational study settings. Further studies, in larger populations, are required to determine the association between work hours and mental health parameters.

Improved Body Mass Index Measures Following a Middle School-Based Obesity Intervention--The MATCH Program

ERIC Educational Resources Information Center

Lazorick, Suzanne; Fang, Xiangming; Hardison, George T.; Crawford, Yancey

2015-01-01

Background: Motivating Adolescents with Technology to CHOOSE Health™ (MATCH) is an educational and behavioral intervention in seventh grade. Methods: Teachers in 2 schools delivered the MATCH curriculum, with 1 control school. Using a quasi-experimental design, outcome measures included lessons completed, body mass index (BMI), BMI z-score (zBMI),…

Indonesian name matching using machine learning supervised approach

NASA Astrophysics Data System (ADS)

Alifikri, Mohamad; Arif Bijaksana, Moch.

2018-03-01

Most existing name matching methods are developed for English language and so they cover the characteristics of this language. Up to this moment, there is no specific one has been designed and implemented for Indonesian names. The purpose of this thesis is to develop Indonesian name matching dataset as a contribution to academic research and to propose suitable feature set by utilizing combination of context of name strings and its permute-winkler score. Machine learning classification algorithms is taken as the method for performing name matching. Based on the experiments, by using tuned Random Forest algorithm and proposed features, there is an improvement of matching performance by approximately 1.7% and it is able to reduce until 70% misclassification result of the state of the arts methods. This improving performance makes the matching system more effective and reduces the risk of misclassified matches.

The Use of Propensity Scores as a Matching Strategy

ERIC Educational Resources Information Center

John, Lindsay; Wright, Robin; Duku, Eric K.; Willms, J. Douglas

2008-01-01

Objectives: This study reports on the concept and method of linear propensity scores used to obtain a comparison group from the National Longitudinal Survey of Children and Youth to assess the effects of a longitudinal, structured arts program for Canadian youth (aged 9 to 15 years) from low-income, multicultural communities. Method: This study…

Fast correspondences search in anatomical trees

NASA Astrophysics Data System (ADS)

dos Santos, Thiago R.; Gergel, Ingmar; Meinzer, Hans-Peter; Maier-Hein, Lena

2010-03-01

Registration of multiple medical images commonly comprises the steps feature extraction, correspondences search and transformation computation. In this paper, we present a new method for a fast and pose independent search of correspondences using as features anatomical trees such as the bronchial system in the lungs or the vessel system in the liver. Our approach scores the similarities between the trees' nodes (bifurcations) taking into account both, topological properties extracted from their graph representations and anatomical properties extracted from the trees themselves. The node assignment maximizes the global similarity (sum of the scores of each pair of assigned nodes), assuring that the matches are distributed throughout the trees. Furthermore, the proposed method is able to deal with distortions in the data, such as noise, motion, artifacts, and problems associated with the extraction method, such as missing or false branches. According to an evaluation on swine lung data sets, the method requires less than one second on average to compute the matching and yields a high rate of correct matches compared to state of the art work.

Effectiveness of the polysaccharide hemostatic powder in non-variceal upper gastrointestinal bleeding: Using propensity score matching.

PubMed

Park, Jun Chul; Kim, Yeong Jin; Kim, Eun Hye; Lee, Jinae; Yang, Hyun Su; Kim, Eun Hwa; Hahn, Kyu Yeon; Shin, Sung Kwan; Lee, Sang Kil; Lee, Yong Chan

2018-02-07

Recently, the application of hemostatic powder to the bleeding site has been used to treat active upper gastrointestinal bleeding (UGIB). We aimed to assess the effectiveness of the polysaccharide hemostatic powder (PHP) in patients with non-variceal UGIB. We reviewed prospectively collected 40 patients with UGIB treated with PHP therapy between April 2016 and January 2017 (PHP group) and 303 patients with UGIB treated with conventional therapy between April 2012 and October 2014 (conventional therapy group). We compared the rate of successful hemostasis and the rebleeding between the two groups after as well as before propensity score matching using the Glasgow-Blatchford score and Forrest classification. Thirty patients treated with the PHP and 60 patients treated with conventional therapy were included in the matched groups. Baseline patient characteristics including comorbidities, vital signs, and bleeding scores were similar in the matched groups. The rate of immediate hemostasis and 7-day and 30-day rebleeding were also similar in the two groups before and after matching. In the subgroup analysis, no significant differences in immediate hemostasis or rebleeding rate were noted between PHP in monotherapy and PHP combined with a conventional hemostatic method. At 30 days after the therapy, there were no significant PHP-related complications or mortality. Given its safety, the PHP proved feasible for endoscopic treatment of UGIB, having similar effectiveness as that of conventional therapy. The PHP may become a promising hemostatic method for non-variceal UGIB. © 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Variability and Diagnostic Accuracy of Speech Intelligibility Scores in Children

ERIC Educational Resources Information Center

Hustad, Katherine C.; Oakes, Ashley; Allison, Kristen

2015-01-01

Purpose: We examined variability of speech intelligibility scores and how well intelligibility scores predicted group membership among 5-year-old children with speech motor impairment (SMI) secondary to cerebral palsy and an age-matched group of typically developing (TD) children. Method: Speech samples varying in length from 1-4 words were…

Early Math Achievement and Functional Connectivity in the Fronto-Parietal Network

PubMed Central

Emerson, Robert W.; Cantlon, Jessica F.

2011-01-01

In this study we test the hypothesis that the functional connectivity of the frontal and parietal regions that children recruit during a basic numerical task (matching Arabic numerals to arrays of dots) is predictive of their math test scores (TEMA-3; Ginsburg 2003). Specifically, we tested 4- to 11-year-old children on a matching task during fMRI to localize a fronto-parietal network that responds more strongly during numerical matching than matching faces, words, or shapes. We then tested the functional connectivity between those regions during an independent task: natural viewing of an educational video that included math topics. Using this novel natural viewing method, we found that the connectivity between frontal and parietal regions during task-independent free-viewing of educational material is correlated with children's basic number matching ability, as well as their scores on the standardized test of mathematical ability (the TEMA). The correlation between children's mathematics scores and fronto-parietal connectivity is math-specific in the sense that it is independent of children's verbal IQ scores. Moreover, a control network, selective for faces, showed no correlation with mathematics performance. Finally, brain regions that correlate with subjects’ overall response times in the matching task do not account for our number- and math-related effects. We suggest that the functional intersection of number-related frontal and parietal regions is math-specific. PMID:22682903

Approximate string matching algorithms for limited-vocabulary OCR output correction

NASA Astrophysics Data System (ADS)

Lasko, Thomas A.; Hauser, Susan E.

2000-12-01

Five methods for matching words mistranslated by optical character recognition to their most likely match in a reference dictionary were tested on data from the archives of the National Library of Medicine. The methods, including an adaptation of the cross correlation algorithm, the generic edit distance algorithm, the edit distance algorithm with a probabilistic substitution matrix, Bayesian analysis, and Bayesian analysis on an actively thinned reference dictionary were implemented and their accuracy rates compared. Of the five, the Bayesian algorithm produced the most correct matches (87%), and had the advantage of producing scores that have a useful and practical interpretation.

Differential Item Functioning Detection with the Mantel-Haenszel Procedure: The Effects of Matching Types and Other Factors

ERIC Educational Resources Information Center

Socha, Alan; DeMars, Christine E.; Zilberberg, Anna; Phan, Ha

2015-01-01

The Mantel-Haenszel (MH) procedure is commonly used to detect items that function differentially for groups of examinees from various demographic and linguistic backgrounds--for example, in international assessments. As in some other DIF methods, the total score is used to match examinees on ability. In thin matching, each of the total score…

Effect of playing tactics on achieving score-box possessions in a random series of team possessions from Norwegian professional soccer matches.

PubMed

Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald

2010-02-01

Methods of analysis that include an assessment of opponent interactions are thought to provide a more valid means of team match performance. The purpose of this study was to examine the effect of playing tactics on achieving score-box possession by assessing opponent interactions in Norwegian elite soccer matches. We analysed a random series of 1703 team possessions from 163 of 182 (90%) matches played in the professional men's league during the 2004 season. Multidimensional qualitative data obtained from ten ordered categorical variables were used. Offensive tactics were more effective in producing score-box possessions when playing against an imbalanced defence (28.5%) than against a balanced defence (6.5%) (P < 0.001). Multiple logistic regression found that, for the main variable "team possession type", counterattacks were more effective than elaborate attacks when playing against an imbalanced defence (odds ratio: 2.69; 95% confidence interval: 1.64 to 4.43) but not against a balanced defence (odds ratio: 1.14; 95% confidence interval: 0.47 to 2.76). Assessment of opponent interactions is critical to evaluate the effectiveness of offensive playing tactics on producing score-box possessions, and improves the validity of team match-performance analysis in soccer.

A consensus algorithm for approximate string matching and its application to QRS complex detection

NASA Astrophysics Data System (ADS)

Alba, Alfonso; Mendez, Martin O.; Rubio-Rincon, Miguel E.; Arce-Santana, Edgar R.

2016-08-01

In this paper, a novel algorithm for approximate string matching (ASM) is proposed. The novelty resides in the fact that, unlike most other methods, the proposed algorithm is not based on the Hamming or Levenshtein distances, but instead computes a score for each symbol in the search text based on a consensus measure. Those symbols with sufficiently high scores will likely correspond to approximate instances of the pattern string. To demonstrate the usefulness of the proposed method, it has been applied to the detection of QRS complexes in electrocardiographic signals with competitive results when compared against the classic Pan-Tompkins (PT) algorithm. The proposed method outperformed PT in 72% of the test cases, with no extra computational cost.

Fuzzy based finger vein recognition with rotation invariant feature matching

NASA Astrophysics Data System (ADS)

Ezhilmaran, D.; Joseph, Rose Bindu

2017-11-01

Finger vein recognition is a promising biometric with commercial applications which is explored widely in the recent years. In this paper, a finger vein recognition system is proposed using rotation invariant feature descriptors for matching after enhancing the finger vein images with an interval type-2 fuzzy method. SIFT features are extracted and matched using a matching score based on Euclidian distance. Rotation invariance of the proposed method is verified in the experiment and the results are compared with SURF matching and minutiae matching. It is seen that rotation invariance is verified and the poor quality issues are solved efficiently with the designed system of finger vein recognition during the analysis. The experiments underlines the robustness and reliability of the interval type-2 fuzzy enhancement and SIFT feature matching.

The Effect of Latent Binary Variables on the Uncertainty of the Prediction of a Dichotomous Outcome Using Logistic Regression Based Propensity Score Matching.

PubMed

Szekér, Szabolcs; Vathy-Fogarassy, Ágnes

2018-01-01

Logistic regression based propensity score matching is a widely used method in case-control studies to select the individuals of the control group. This method creates a suitable control group if all factors affecting the output variable are known. However, if relevant latent variables exist as well, which are not taken into account during the calculations, the quality of the control group is uncertain. In this paper, we present a statistics-based research in which we try to determine the relationship between the accuracy of the logistic regression model and the uncertainty of the dependent variable of the control group defined by propensity score matching. Our analyses show that there is a linear correlation between the fit of the logistic regression model and the uncertainty of the output variable. In certain cases, a latent binary explanatory variable can result in a relative error of up to 70% in the prediction of the outcome variable. The observed phenomenon calls the attention of analysts to an important point, which must be taken into account when deducting conclusions.

Controlling Type I Error Rates in Assessing DIF for Logistic Regression Method Combined with SIBTEST Regression Correction Procedure and DIF-Free-Then-DIF Strategy

ERIC Educational Resources Information Center

Shih, Ching-Lin; Liu, Tien-Hsiang; Wang, Wen-Chung

2014-01-01

The simultaneous item bias test (SIBTEST) method regression procedure and the differential item functioning (DIF)-free-then-DIF strategy are applied to the logistic regression (LR) method simultaneously in this study. These procedures are used to adjust the effects of matching true score on observed score and to better control the Type I error…

The impacts of speed cameras on road accidents: an application of propensity score matching methods.

PubMed

Li, Haojie; Graham, Daniel J; Majumdar, Arnab

2013-11-01

This paper aims to evaluate the impacts of speed limit enforcement cameras on reducing road accidents in the UK by accounting for both confounding factors and the selection of proper reference groups. The propensity score matching (PSM) method is employed to do this. A naïve before and after approach and the empirical Bayes (EB) method are compared with the PSM method. A total of 771 sites and 4787 sites for the treatment and the potential reference groups respectively are observed for a period of 9 years in England. Both the PSM and the EB methods show similar results that there are significant reductions in the number of accidents of all severities at speed camera sites. It is suggested that the propensity score can be used as the criteria for selecting the reference group in before-after control studies. Speed cameras were found to be most effective in reducing accidents up to 200 meters from camera sites and no evidence of accident migration was found. Copyright © 2013 Elsevier Ltd. All rights reserved.

The expected value of possession in professional rugby league match-play.

PubMed

Kempton, Thomas; Kennedy, Nicholas; Coutts, Aaron J

2016-01-01

This study estimated the expected point value for starting possessions in different field locations during rugby league match-play and calculated the mean expected points for each subsequent play during the possession. It also examined the origin of tries scored according to the method of gaining possession. Play-by-play data were taken from all 768 regular-season National Rugby League (NRL) matches during 2010-2013. A probabilistic model estimated the expected point outcome based on the net difference in points scored by a team in possession in a given situation. An iterative method was used to approximate the value of each situation based on actual scoring outcomes. Possessions commencing close to the opposition's goal-line had the highest expected point equity, which decreased as the location of the possession moved towards the team's own goal-line. Possessions following an opposition error, penalty or goal-line dropout had the highest likelihood of a try being scored on the set subsequent to their occurrence. In contrast, possessions that follow an opposition completed set or a restart were least likely to result in a try. The expected point values framework from our model has applications for informing playing strategy and assessing individual and team performance in professional rugby league.

Integrating data from randomized controlled trials and observational studies to predict the response to pregabalin in patients with painful diabetic peripheral neuropathy.

PubMed

Alexander, Joe; Edwards, Roger A; Savoldelli, Alberto; Manca, Luigi; Grugni, Roberto; Emir, Birol; Whalen, Ed; Watt, Stephen; Brodsky, Marina; Parsons, Bruce

2017-07-20

More patient-specific medical care is expected as more is learned about variations in patient responses to medical treatments. Analytical tools enable insights by linking treatment responses from different types of studies, such as randomized controlled trials (RCTs) and observational studies. Given the importance of evidence from both types of studies, our goal was to integrate these types of data into a single predictive platform to help predict response to pregabalin in individual patients with painful diabetic peripheral neuropathy (pDPN). We utilized three pivotal RCTs of pregabalin (398 North American patients) and the largest observational study of pregabalin (3159 German patients). We implemented a hierarchical cluster analysis to identify patient clusters in the Observational Study to which RCT patients could be matched using the coarsened exact matching (CEM) technique, thereby creating a matched dataset. We then developed autoregressive moving average models (ARMAXs) to estimate weekly pain scores for pregabalin-treated patients in each cluster in the matched dataset using the maximum likelihood method. Finally, we validated ARMAX models using Observational Study patients who had not matched with RCT patients, using t tests between observed and predicted pain scores. Cluster analysis yielded six clusters (287-777 patients each) with the following clustering variables: gender, age, pDPN duration, body mass index, depression history, pregabalin monotherapy, prior gabapentin use, baseline pain score, and baseline sleep interference. CEM yielded 1528 unique patients in the matched dataset. The reduction in global imbalance scores for the clusters after adding the RCT patients (ranging from 6 to 63% depending on the cluster) demonstrated that the process reduced the bias of covariates in five of the six clusters. ARMAX models of pain score performed well (R 2 : 0.85-0.91; root mean square errors: 0.53-0.57). t tests did not show differences between observed and predicted pain scores in the 1955 patients who had not matched with RCT patients. The combination of cluster analyses, CEM, and ARMAX modeling enabled strong predictive capabilities with respect to pain scores. Integrating RCT and Observational Study data using CEM enabled effective use of Observational Study data to predict patient responses.

Generalizing Observational Study Results: Applying Propensity Score Methods to Complex Surveys

PubMed Central

DuGoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-01-01

ObjectiveTo provide a tutorial for using propensity score methods with complex survey data. Data SourcesSimulated data and the 2008 Medical Expenditure Panel Survey. Study DesignUsing simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. Principal FindingsIn general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. ConclusionsPropensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher’s goal. PMID:23855598

Generalizing observational study results: applying propensity score methods to complex surveys.

PubMed

Dugoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-02-01

To provide a tutorial for using propensity score methods with complex survey data. Simulated data and the 2008 Medical Expenditure Panel Survey. Using simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. In general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. Propensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher's goal. © Health Research and Educational Trust.

Matching on the disease risk score in comparative effectiveness research of new treatments.

PubMed

Wyss, Richard; Ellis, Alan R; Brookhart, M Alan; Jonsson Funk, Michele; Girman, Cynthia J; Simpson, Ross J; Stürmer, Til

2015-09-01

We use simulations and an empirical example to evaluate the performance of disease risk score (DRS) matching compared with propensity score (PS) matching when controlling large numbers of covariates in settings involving newly introduced treatments. We simulated a dichotomous treatment, a dichotomous outcome, and 100 baseline covariates that included both continuous and dichotomous random variables. For the empirical example, we evaluated the comparative effectiveness of dabigatran versus warfarin in preventing combined ischemic stroke and all-cause mortality. We matched treatment groups on a historically estimated DRS and again on the PS. We controlled for a high-dimensional set of covariates using 20% and 1% samples of Medicare claims data from October 2010 through December 2012. In simulations, matching on the DRS versus the PS generally yielded matches for more treated individuals and improved precision of the effect estimate. For the empirical example, PS and DRS matching in the 20% sample resulted in similar hazard ratios (0.88 and 0.87) and standard errors (0.04 for both methods). In the 1% sample, PS matching resulted in matches for only 92.0% of the treated population and a hazard ratio and standard error of 0.89 and 0.19, respectively, while DRS matching resulted in matches for 98.5% and a hazard ratio and standard error of 0.85 and 0.16, respectively. When PS distributions are separated, DRS matching can improve the precision of effect estimates and allow researchers to evaluate the treatment effect in a larger proportion of the treated population. However, accurately modeling the DRS can be challenging compared with the PS. Copyright © 2015 John Wiley & Sons, Ltd.

A Sorting-to-Matching Method to Teach Compound Matching to Sample

ERIC Educational Resources Information Center

Farber, Rachel S.; Dube, William V.; Dickson, Chata A.

2016-01-01

Individuals with developmental disabilities may fail to attend to multiple features in compound stimuli (e.g., arrays of pictures, letters within words) with detrimental effects on learning. Participants were 5 children with autism spectrum disorder who had low to intermediate accuracy scores (35% to 84%) on a computer-presented compound matching…

A weak pattern random creation and scoring method for lithography process tuning

NASA Astrophysics Data System (ADS)

Zhang, Meili; Deng, Guogui; Wang, Mudan; Yu, Shirui; Hu, Xinyi; Du, Chunshan; Wan, Qijian; Liu, Zhengfang; Gao, Gensheng; Kabeel, Aliaa; Madkour, Kareem; ElManhawy, Wael; Kwan, Joe

2018-03-01

As the IC technology node moves forward, critical dimension becomes smaller and smaller, which brings huge challenge to IC manufacturing. Lithography is one of the most important steps during the whole manufacturing process and litho hotspots become a big source of yield detractors. Thus tuning lithographic recipes to cover a big range of litho hotspots is very essential to yield enhancing. During early technology developing stage, foundries only have limited customer layout data for recipe tuning. So collecting enough patterns is significant for process optimization. After accumulating enough patterns, a general way to treat them is not precise and applicable. Instead, an approach to scoring these patterns could provide a priority and reference to address different patterns more effectively. For example, the weakest group of patterns could be applied the most limited specs to ensure process robustness. This paper presents a new method of creation of real design alike patterns of multiple layers based on design rules using Layout Schema Generator (LSG) utility and a pattern scoring flow using Litho-friendly Design (LFD) and Pattern Matching. Through LSG, plenty of new unknown patterns could be created for further exploration. Then, litho simulation through LFD and topological matches by using Pattern Matching is applied on the output patterns of LSG. Finally, lithographical severity, printability properties and topological distribution of every pattern are collected. After a statistical analysis of pattern data, every pattern is given a relative score representing the pattern's yield detracting level. By sorting the output pattern score tables, weak patterns could be filtered out for further research and process tuning. This pattern generation and scoring flow is demonstrated on 28nm logic technology node. A weak pattern library is created and scored to help improve recipe coverage of litho hotspots and enhance the reliability of process.

Propensity Scores in Pharmacoepidemiology: Beyond the Horizon.

PubMed

Jackson, John W; Schmid, Ian; Stuart, Elizabeth A

2017-12-01

Propensity score methods have become commonplace in pharmacoepidemiology over the past decade. Their adoption has confronted formidable obstacles that arise from pharmacoepidemiology's reliance on large healthcare databases of considerable heterogeneity and complexity. These include identifying clinically meaningful samples, defining treatment comparisons, and measuring covariates in ways that respect sound epidemiologic study design. Additional complexities involve correctly modeling treatment decisions in the face of variation in healthcare practice, and dealing with missing information and unmeasured confounding. In this review, we examine the application of propensity score methods in pharmacoepidemiology with particular attention to these and other issues, with an eye towards standards of practice, recent methodological advances, and opportunities for future progress. Propensity score methods have matured in ways that can advance comparative effectiveness and safety research in pharmacoepidemiology. These include natural extensions for categorical treatments, matching algorithms that can optimize sample size given design constraints, weighting estimators that asymptotically target matched and overlap samples, and the incorporation of machine learning to aid in covariate selection and model building. These recent and encouraging advances should be further evaluated through simulation and empirical studies, but nonetheless represent a bright path ahead for the observational study of treatment benefits and harms.

Methods for Constructing and Assessing Propensity Scores

PubMed Central

Garrido, Melissa M; Kelley, Amy S; Paris, Julia; Roza, Katherine; Meier, Diane E; Morrison, R Sean; Aldridge, Melissa D

2014-01-01

Objectives To model the steps involved in preparing for and carrying out propensity score analyses by providing step-by-step guidance and Stata code applied to an empirical dataset. Study Design Guidance, Stata code, and empirical examples are given to illustrate (1) the process of choosing variables to include in the propensity score; (2) balance of propensity score across treatment and comparison groups; (3) balance of covariates across treatment and comparison groups within blocks of the propensity score; (4) choice of matching and weighting strategies; (5) balance of covariates after matching or weighting the sample; and (6) interpretation of treatment effect estimates. Empirical Application We use data from the Palliative Care for Cancer Patients (PC4C) study, a multisite observational study of the effect of inpatient palliative care on patient health outcomes and health services use, to illustrate the development and use of a propensity score. Conclusions Propensity scores are one useful tool for accounting for observed differences between treated and comparison groups. Careful testing of propensity scores is required before using them to estimate treatment effects. PMID:24779867

Five-Factor Model personality disorder prototypes: a review of their development, validity, and comparison to alternative approaches.

PubMed

Miller, Joshua D

2012-12-01

In this article, the development of Five-Factor Model (FFM) personality disorder (PD) prototypes for the assessment of DSM-IV PDs are reviewed, as well as subsequent procedures for scoring individuals' FFM data with regard to these PD prototypes, including similarity scores and simple additive counts that are based on a quantitative prototype matching methodology. Both techniques, which result in very strongly correlated scores, demonstrate convergent and discriminant validity, and provide clinically useful information with regard to various forms of functioning. The techniques described here for use with FFM data are quite different from the prototype matching methods used elsewhere. © 2012 The Author. Journal of Personality © 2012, Wiley Periodicals, Inc.

Assisted reproductive technology has no association with autism spectrum disorders: The Taiwan Birth Cohort Study.

PubMed

Lung, For-Wey; Chiang, Tung-Liang; Lin, Shio-Jean; Lee, Meng-Chih; Shu, Bih-Ching

2018-04-01

The use of assisted reproduction technology has increased over the last two decades. Autism spectrum disorders and assisted reproduction technology share many risk factors. However, previous studies on the association between autism spectrum disorders and assisted reproduction technology have shown inconsistent results. The purpose of this study was to investigate the association between assisted reproduction technology and autism spectrum disorder diagnosis in a national birth cohort database. Furthermore, the results from the assisted reproduction technology and autism spectrum disorder propensity score matching exact matched datasets were compared. For this study, the 6- and 66-month Taiwan Birth Cohort Study datasets were used (N = 20,095). In all, 744 families were propensity score matching exact matched and selected as the assisted reproduction technology sample (ratio of assisted reproduction technology to controls: 1:2) and 415 families as the autism spectrum disorder sample (ratio of autism spectrum disorder to controls: 1:4). Using a national birth cohort dataset, controlling for the confounding factors of assisted reproduction technology conception and autism spectrum disorder diagnosis, both assisted reproduction technology and autism spectrum disorder propensity score matching matched datasets showed the same results of no association between assisted reproduction technology and autism spectrum disorder. Further study on the detailed information regarding the processes and methods of assisted reproduction technology may provide us with more information on the association between assisted reproduction technology and autism spectrum disorder.

A Step-by-Step Guide to Propensity Score Matching in R

ERIC Educational Resources Information Center

Randolph, Justus J.; Falbe, Kristina; Manuel, Austin Kureethara; Balloun, Joseph L.

2014-01-01

Propensity score matching is a statistical technique in which a treatment case is matched with one or more control cases based on each case's propensity score. This matching can help strengthen causal arguments in quasi-experimental and observational studies by reducing selection bias. In this article we concentrate on how to conduct propensity…

Assessing Student Achievement in Large-Scale Educational Programs Using Hierarchical Propensity Scores

ERIC Educational Resources Information Center

Vaughan, Angela L.; Lalonde, Trent L.; Jenkins-Guarnieri, Michael A.

2014-01-01

Many researchers assessing the efficacy of educational programs face challenges due to issues with non-randomization and the likelihood of dependence between nested subjects. The purpose of the study was to demonstrate a rigorous research methodology using a hierarchical propensity score matching method that can be utilized in contexts where…

Evaluation of Barrier Skin Cream Effectiveness Against JP-8 Jet Fuel Absorption and Irritation

DTIC Science & Technology

2009-04-01

quantify the colorimeter measurements. This system uses spectral chromaticity coordinates and corresponding color- matching functions based on...in the caudal thigh or lumbar muscles and the rabbit was monitored throughout the procedure. Once anesthetized, a baseline visual and colorimeter ...Visual Scoring Technique All barrier creams were scored in 3 ways; by visual scoring described in the Draize method, by colorimeter , and by

Evaluation of subset matching methods and forms of covariate balance.

PubMed

de Los Angeles Resa, María; Zubizarreta, José R

2016-11-30

This paper conducts a Monte Carlo simulation study to evaluate the performance of multivariate matching methods that select a subset of treatment and control observations. The matching methods studied are the widely used nearest neighbor matching with propensity score calipers and the more recently proposed methods, optimal matching of an optimally chosen subset and optimal cardinality matching. The main findings are: (i) covariate balance, as measured by differences in means, variance ratios, Kolmogorov-Smirnov distances, and cross-match test statistics, is better with cardinality matching because by construction it satisfies balance requirements; (ii) for given levels of covariate balance, the matched samples are larger with cardinality matching than with the other methods; (iii) in terms of covariate distances, optimal subset matching performs best; (iv) treatment effect estimates from cardinality matching have lower root-mean-square errors, provided strong requirements for balance, specifically, fine balance, or strength-k balance, plus close mean balance. In standard practice, a matched sample is considered to be balanced if the absolute differences in means of the covariates across treatment groups are smaller than 0.1 standard deviations. However, the simulation results suggest that stronger forms of balance should be pursued in order to remove systematic biases due to observed covariates when a difference in means treatment effect estimator is used. In particular, if the true outcome model is additive, then marginal distributions should be balanced, and if the true outcome model is additive with interactions, then low-dimensional joints should be balanced. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Does gender and experience influence shade matching quality?

PubMed

Haddad, Helene J; Jakstat, Holger A; Arnetzl, Gerwin; Borbely, Judit; Vichi, Alessandro; Dumfahrt, Herbert; Renault, Patrick; Corcodel, Nicoleta; Pohlen, Bostjan; Marada, Gyula; de Parga, Juan A Martinez Vazquez; Reshad, Mamaly; Klinke, Thomas U; Hannak, Wolfgang B; Paravina, Rade D

2009-01-01

To evaluate the influence of gender and level of experience on shade matching quality. A study was simultaneously performed at 15 universities located in 9 countries. A total of 614 color normal participants completed all phases of the experiment. Among them, there were 305 females and 309 males, 319 dental students and 295 dental professionals. A lecture on color matching in dentistry was given to all participants. Initial training was performed using Toothguide Trainer software (TT), while Toothguide Training Box (TTB) was used for both training and testing of participants' shade matching results. The test task was to successively match 15 shade guide tabs with the corresponding shade guide. The shade matching score for each participant was computed as a sum of color differences (SigmaDeltaE(ab)(*) score) between target tabs and selected tabs. Lower scores corresponded to better shade matching results and vice versa. Means and standard deviations were calculated. Mann-Whitney U test was used for statistical analysis of the data (alpha=0.05). The mean shade matching score (S.D.) for all participants was 41 (21). The score for female and male participants was 38 (20) and 44 (21), respectfully (p<0.001). The difference in scores between dental students, 42 (20), and dental professionals, 39 (21), was not statistically significant. Within the limitations of this study, females achieved significantly better shade matching results than males, indicating that gender plays an important role in shade matching. The level of experience was not found to be significant factor in shade matching.

With Some Help from Others' Hands: Iconic Gesture Helps Semantic Learning in Children with Specific Language Impairment

ERIC Educational Resources Information Center

Vogt, Susanne S.; Kauschke, Christina

2017-01-01

Purpose: Semantic learning under 2 co-speech gesture conditions was investigated in children with specific language impairment (SLI) and typically developing (TD) children. Learning was analyzed between conditions. Method: Twenty children with SLI (aged 4 years), 20 TD children matched for age, and 20 TD children matched for language scores were…

Preoperative selective desensitization of live donor liver transplant recipients considering the degree of T lymphocyte cross-match titer, model for end-stage liver disease score, and graft liver volume.

PubMed

Hong, Geun; Yi, Nam-Joon; Suh, Suk-won; Yoo, Tae; Kim, Hyeyoung; Park, Min-Su; Choi, YoungRok; Lee, Kyungbun; Lee, Kwang-Woong; Park, Myoung Hee; Suh, Kyung-Suk

2014-05-01

Several studies have suggested that a positive lymphocyte cross-matching (XM) is associated with low graft survival rates and a high prevalence of acute rejection after adult living donor liver transplantations (ALDLTs) using a small-for-size graft. However, there is still no consensus on preoperative desensitization. We adopted the desensitization protocol from ABO-incompatible LDLT. We performed desensitization for the selected patients according to the degree of T lymphocyte cross-match titer, model for end-stage liver disease (MELD) score, and graft liver volume. We retrospectively evaluated 230 consecutive ALDLT recipients for 5 yr. Eleven recipients (4.8%) showed a positive XM. Among them, five patients with the high titer (> 1:16) by antihuman globulin-augmented method (T-AHG) and one with a low titer but a high MELD score of 36 were selected for desensitization: rituximab injection and plasmapheresis before the transplantation. There were no major side effects of desensitization. Four of the patients showed successful depletion of the T-AHG titer. There was no mortality and hyperacute rejection in lymphocyte XM-positive patients, showing no significant difference in survival outcome between two groups (P=1.000). In conclusion, this desensitization protocol for the selected recipients considering the degree of T lymphocyte cross-match titer, MELD score, and graft liver volume is feasible and safe.

Effect of playing tactics on goal scoring in Norwegian professional soccer.

PubMed

Tenga, Albin; Holme, Ingar; Ronglan, Lars Tore; Bahr, Roald

2010-02-01

Methods that include an assessment of opponent interactions are thought to provide a more valid analysis of team match performance. The purpose of this study was to examine the effect of playing tactics on goal scoring by assessing opponent interactions in Norwegian elite soccer. The sample included 203 team possessions leading to goals (cases) and 1688 random team possessions (control group) from 163 of 182 (90%) matches played in the men's professional league during the 2004 season. Multidimensional qualitative data using ten ordered categorical variables were obtained to characterize each team possession. The proportion of goals scored during counterattacks (52%) was higher than during elaborate attacks (48%), while for the control group the proportion using elaborate attacks (59%) was higher than when using counterattacks (41%) (P = 0.002). Multiple logistic regression analyses showed that, for the main variable "team possession type", counterattacks were more effective than elaborate attacks when playing against an imbalanced defence (OR = 1.64; 95% confidence interval: 1.03 to 2.61; P = 0.038). Assessment of opponent interactions is critical to evaluate the effectiveness of offensive playing tactics on the probability of scoring goals, and improves the validity of team match-performance analysis in soccer.

Empirical Implications of Matching Children With Specific Language Impairment to Children With Typical Development on Nonverbal IQ.

PubMed

Earle, F Sayako; Gallinat, Erica L; Grela, Bernard G; Lehto, Alexa; Spaulding, Tammie J

This study determined the effect of matching children with specific language impairment (SLI) and their peers with typical development (TD) for nonverbal IQ on the IQ test scores of the resultant groups. Studies published between January 2000 and May 2012 reporting standard nonverbal IQ scores for SLI and age-matched TD controls were categorized into those that matched and did not match children with SLI and TD on nonverbal IQ. We then compared the nonverbal IQ scores across matching criterions within each diagnostic category. In studies that matched children on nonverbal IQ, children with SLI scored significantly higher on nonverbal IQ tests relative to children with SLI in studies that did not match on this criterion. Therefore, it appears that the nonverbal IQ performance of children with SLI is not comparable across studies that do and do not match samples on nonverbal IQ. This suggests that the practice of nonverbal IQ matching may have unintended consequences for the generalization of research findings to the broader SLI population.

Issues Related to Obtaining Intelligence Quotient-Matched Controls in Autism Research

PubMed Central

Rao, Vanitha S.; Raman, Vijaya; Mysore, Ashok V.

2015-01-01

Background: Intelligence Quotient (IQ) is considered to be an index of global cognitive functioning and has traditionally been used as a fulcral measure in case-control studies in neuro-developmental disorders such as autism. Aim: The aim is to highlight the issues of “matching for IQ” with controls in autism research. Materials and Methods: Percentile scores on the Coloured Progressive Matrices of 20 children with autism in the age range of 5 to 12 years have been graphically compared with 21 age matched typically developing children. Results and Conclusions: The percentile scores of the so-called high functioning children with autism from special schools were well below that of typically developing children. There are many challenges when using IQ in case-control studies of autism. Alternative approaches need to be considered. PMID:25969598

Estimating the Effectiveness of Health-Risk Communications with Propensity-Score Matching: Application to Arsenic Groundwater Contamination in Four US Locations

PubMed Central

Leidner, Andrew J.

2014-01-01

This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household's decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research. PMID:25349622

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis

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

Ahrar, Judy U., E-mail: judy.ahrar@mdanderson.org; Gupta, Sanjay; Ensor, Joe E.

PurposeTo evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy.Materials and MethodsIn this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if themore » absolute difference in their propensity scores was ≤equal to 0.02.ResultsBefore matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates.ConclusionsThe self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.« less

A new algorithm for distorted fingerprints matching based on normalized fuzzy similarity measure.

PubMed

Chen, Xinjian; Tian, Jie; Yang, Xin

2006-03-01

Coping with nonlinear distortions in fingerprint matching is a challenging task. This paper proposes a novel algorithm, normalized fuzzy similarity measure (NFSM), to deal with the nonlinear distortions. The proposed algorithm has two main steps. First, the template and input fingerprints were aligned. In this process, the local topological structure matching was introduced to improve the robustness of global alignment. Second, the method NFSM was introduced to compute the similarity between the template and input fingerprints. The proposed algorithm was evaluated on fingerprints databases of FVC2004. Experimental results confirm that NFSM is a reliable and effective algorithm for fingerprint matching with nonliner distortions. The algorithm gives considerably higher matching scores compared to conventional matching algorithms for the deformed fingerprints.

Efficient Iris Recognition Based on Optimal Subfeature Selection and Weighted Subregion Fusion

PubMed Central

Deng, Ning

2014-01-01

In this paper, we propose three discriminative feature selection strategies and weighted subregion matching method to improve the performance of iris recognition system. Firstly, we introduce the process of feature extraction and representation based on scale invariant feature transformation (SIFT) in detail. Secondly, three strategies are described, which are orientation probability distribution function (OPDF) based strategy to delete some redundant feature keypoints, magnitude probability distribution function (MPDF) based strategy to reduce dimensionality of feature element, and compounded strategy combined OPDF and MPDF to further select optimal subfeature. Thirdly, to make matching more effective, this paper proposes a novel matching method based on weighted sub-region matching fusion. Particle swarm optimization is utilized to accelerate achieve different sub-region's weights and then weighted different subregions' matching scores to generate the final decision. The experimental results, on three public and renowned iris databases (CASIA-V3 Interval, Lamp, andMMU-V1), demonstrate that our proposed methods outperform some of the existing methods in terms of correct recognition rate, equal error rate, and computation complexity. PMID:24683317

Efficient iris recognition based on optimal subfeature selection and weighted subregion fusion.

PubMed

Chen, Ying; Liu, Yuanning; Zhu, Xiaodong; He, Fei; Wang, Hongye; Deng, Ning

2014-01-01

In this paper, we propose three discriminative feature selection strategies and weighted subregion matching method to improve the performance of iris recognition system. Firstly, we introduce the process of feature extraction and representation based on scale invariant feature transformation (SIFT) in detail. Secondly, three strategies are described, which are orientation probability distribution function (OPDF) based strategy to delete some redundant feature keypoints, magnitude probability distribution function (MPDF) based strategy to reduce dimensionality of feature element, and compounded strategy combined OPDF and MPDF to further select optimal subfeature. Thirdly, to make matching more effective, this paper proposes a novel matching method based on weighted sub-region matching fusion. Particle swarm optimization is utilized to accelerate achieve different sub-region's weights and then weighted different subregions' matching scores to generate the final decision. The experimental results, on three public and renowned iris databases (CASIA-V3 Interval, Lamp, and MMU-V1), demonstrate that our proposed methods outperform some of the existing methods in terms of correct recognition rate, equal error rate, and computation complexity.

An improved finger-vein recognition algorithm based on template matching

NASA Astrophysics Data System (ADS)

Liu, Yueyue; Di, Si; Jin, Jian; Huang, Daoping

2016-10-01

Finger-vein recognition has became the most popular biometric identify methods. The investigation on the recognition algorithms always is the key point in this field. So far, there are many applicable algorithms have been developed. However, there are still some problems in practice, such as the variance of the finger position which may lead to the image distortion and shifting; during the identification process, some matching parameters determined according to experience may also reduce the adaptability of algorithm. Focus on above mentioned problems, this paper proposes an improved finger-vein recognition algorithm based on template matching. In order to enhance the robustness of the algorithm for the image distortion, the least squares error method is adopted to correct the oblique finger. During the feature extraction, local adaptive threshold method is adopted. As regard as the matching scores, we optimized the translation preferences as well as matching distance between the input images and register images on the basis of Naoto Miura algorithm. Experimental results indicate that the proposed method can improve the robustness effectively under the finger shifting and rotation conditions.

Brachytherapy Improves Biochemical Failure–Free Survival in Low- and Intermediate-Risk Prostate Cancer Compared With Conventionally Fractionated External Beam Radiation Therapy: A Propensity Score Matched Analysis

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

Smith, Graham D.; Pickles, Tom; Crook, Juanita

2015-03-01

Purpose: To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Methods and Materials: Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2)more » intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Results: Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Conclusions: Propensity score matched analysis showed that BT options led to statistically significant improvements in bFFS in low- and intermediate-risk prostate cancer patient populations.« less

A Non-parametric Cutout Index for Robust Evaluation of Identified Proteins*

PubMed Central

Serang, Oliver; Paulo, Joao; Steen, Hanno; Steen, Judith A.

2013-01-01

This paper proposes a novel, automated method for evaluating sets of proteins identified using mass spectrometry. The remaining peptide-spectrum match score distributions of protein sets are compared to an empirical absent peptide-spectrum match score distribution, and a Bayesian non-parametric method reminiscent of the Dirichlet process is presented to accurately perform this comparison. Thus, for a given protein set, the process computes the likelihood that the proteins identified are correctly identified. First, the method is used to evaluate protein sets chosen using different protein-level false discovery rate (FDR) thresholds, assigning each protein set a likelihood. The protein set assigned the highest likelihood is used to choose a non-arbitrary protein-level FDR threshold. Because the method can be used to evaluate any protein identification strategy (and is not limited to mere comparisons of different FDR thresholds), we subsequently use the method to compare and evaluate multiple simple methods for merging peptide evidence over replicate experiments. The general statistical approach can be applied to other types of data (e.g. RNA sequencing) and generalizes to multivariate problems. PMID:23292186

Accuracy of very low pretest probability estimates for pulmonary embolism using the method of attribute matching compared with the Wells score.

PubMed

Kline, Jeffrey A; Courtney, D Mark; Than, Martin P; Hogg, Kerstin; Miller, Chadwick D; Johnson, Charles L; Smithline, Howard A

2010-02-01

Attribute matching matches an explicit clinical profile of a patient to a reference database to estimate the numeric value for the pretest probability of an acute disease. The authors tested the accuracy of this method for forecasting a very low probability of venous thromboembolism (VTE) in symptomatic emergency department (ED) patients. The authors performed a secondary analysis of five data sets from 15 hospitals in three countries. All patients had data collected at the time of clinical evaluation for suspected pulmonary embolism (PE). The criterion standard to exclude VTE required no evidence of PE or deep venous thrombosis (DVT) within 45 days of enrollment. To estimate pretest probabilities, a computer program selected, from a large reference database of patients previously evaluated for PE, patients who matched 10 predictor variables recorded for each current test patient. The authors compared the outcome frequency of having VTE [VTE(+)] in patients with a pretest probability estimate of <2.5% by attribute matching, compared with a value of 0 from the Wells score. The five data sets included 10,734 patients, and 747 (7.0%, 95% confidence interval [CI] = 6.5% to 7.5%) were VTE(+) within 45 days. The pretest probability estimate for PE was <2.5% in 2,975 of 10,734 (27.7%) patients, and within this subset, the observed frequency of VTE(+) was 48 of 2,975 (1.6%, 95% CI = 1.2% to 2.1%). The lowest possible Wells score (0) was observed in 3,412 (31.7%) patients, and within this subset, the observed frequency of VTE(+) was 79 of 3,412 (2.3%, 95% CI = 1.8% to 2.9%) patients. Attribute matching categorizes over one-quarter of patients tested for PE as having a pretest probability of <2.5%, and the observed rate of VTE within 45 days in this subset was <2.5%. (c) 2010 by the Society for Academic Emergency Medicine.

Functional annotation by sequence-weighted structure alignments: statistical analysis and case studies from the Protein 3000 structural genomics project in Japan.

PubMed

Standley, Daron M; Toh, Hiroyuki; Nakamura, Haruki

2008-09-01

A method to functionally annotate structural genomics targets, based on a novel structural alignment scoring function, is proposed. In the proposed score, position-specific scoring matrices are used to weight structurally aligned residue pairs to highlight evolutionarily conserved motifs. The functional form of the score is first optimized for discriminating domains belonging to the same Pfam family from domains belonging to different families but the same CATH or SCOP superfamily. In the optimization stage, we consider four standard weighting functions as well as our own, the "maximum substitution probability," and combinations of these functions. The optimized score achieves an area of 0.87 under the receiver-operating characteristic curve with respect to identifying Pfam families within a sequence-unique benchmark set of domain pairs. Confidence measures are then derived from the benchmark distribution of true-positive scores. The alignment method is next applied to the task of functionally annotating 230 query proteins released to the public as part of the Protein 3000 structural genomics project in Japan. Of these queries, 78 were found to align to templates with the same Pfam family as the query or had sequence identities > or = 30%. Another 49 queries were found to match more distantly related templates. Within this group, the template predicted by our method to be the closest functional relative was often not the most structurally similar. Several nontrivial cases are discussed in detail. Finally, 103 queries matched templates at the fold level, but not the family or superfamily level, and remain functionally uncharacterized. 2008 Wiley-Liss, Inc.

The association of USMLE Step 1 and Step 2 CK scores with residency match specialty and location.

PubMed

Gauer, Jacqueline L; Jackson, J Brooks

2017-01-01

For future physicians, residency programs offer necessary extended training in specific medical specialties. Medical schools benefit from an understanding of factors that lead their students to match into certain residency specialties. One such factor, often used during the residency application process, is scores on the USA Medical Licensing Exam (USMLE). To determine the relationship between USMLE Step 1 and Step 2 Clinical Knowledge (CK) scores and students' residency specialty match, and the association between both USMLE scores and state of legal residency (Minnesota) at the time of admission with students staying in-state or leaving the state for residency program. USMLE scores and residency match data were analyzed from five graduating classes of students at the University of Minnesota Medical School (N = 1054). A MANOVA found significant differences (p < 0.001) between residency specialties and both USMLE Step 1 and Step 2 CK scores, as well as the combination of the two. Students who matched in Dermatology had the highest mean USMLE scores overall, while students who matched in Family Medicine had the lowest mean scores. Students who went out of state for residency had significantly higher Step 1 scores (p = 0.027) than students who stayed in-state for residency, while there was no significant difference between the groups for Step 2 scores. A significant positive association was found between a student who applied as a legal resident of Minnesota and whether the student stayed in Minnesota for their residency program. Residency specialty match was significantly associated with USMLE Step 1 and USMLE Step 2 CK scores, as was staying in-state or leaving the state for residency. Students who were legal residents of the state at the time of application were more likely to stay in-state for residency, regardless of USMLE score. CK: Clinical knowledge; COMLEX: Comprehensive Osteopathic Medical Licensing Examination; GME: Graduate medical education; NRMP: National Resident Matching Program; UME: Undergraduate medical education; USMLE: United States Medical Licensing Examination.

The association of USMLE Step 1 and Step 2 CK scores with residency match specialty and location

PubMed Central

Gauer, Jacqueline L.; Jackson, J. Brooks

2017-01-01

ABSTRACT Background: For future physicians, residency programs offer necessary extended training in specific medical specialties. Medical schools benefit from an understanding of factors that lead their students to match into certain residency specialties. One such factor, often used during the residency application process, is scores on the USA Medical Licensing Exam (USMLE). Objectives: To determine the relationship between USMLE Step 1 and Step 2 Clinical Knowledge (CK) scores and students’ residency specialty match, and the association between both USMLE scores and state of legal residency (Minnesota) at the time of admission with students staying in-state or leaving the state for residency program. Design: USMLE scores and residency match data were analyzed from five graduating classes of students at the University of Minnesota Medical School (N = 1054). Results: A MANOVA found significant differences (p < 0.001) between residency specialties and both USMLE Step 1 and Step 2 CK scores, as well as the combination of the two. Students who matched in Dermatology had the highest mean USMLE scores overall, while students who matched in Family Medicine had the lowest mean scores. Students who went out of state for residency had significantly higher Step 1 scores (p = 0.027) than students who stayed in-state for residency, while there was no significant difference between the groups for Step 2 scores. A significant positive association was found between a student who applied as a legal resident of Minnesota and whether the student stayed in Minnesota for their residency program. Conclusions: Residency specialty match was significantly associated with USMLE Step 1 and USMLE Step 2 CK scores, as was staying in-state or leaving the state for residency. Students who were legal residents of the state at the time of application were more likely to stay in-state for residency, regardless of USMLE score. Abbreviations: CK: Clinical knowledge; COMLEX: Comprehensive Osteopathic Medical Licensing Examination; GME: Graduate medical education; NRMP: National Resident Matching Program; UME: Undergraduate medical education; USMLE: United States Medical Licensing Examination PMID:28762297

Charting improvements in US registry HLA typing ambiguity using a typing resolution score.

PubMed

Paunić, Vanja; Gragert, Loren; Schneider, Joel; Müller, Carlheinz; Maiers, Martin

2016-07-01

Unrelated stem cell registries have been collecting HLA typing of volunteer bone marrow donors for over 25years. Donor selection for hematopoietic stem cell transplantation is based primarily on matching the alleles of donors and patients at five polymorphic HLA loci. As HLA typing technologies have continually advanced since the beginnings of stem cell transplantation, registries have accrued typings of varied HLA typing ambiguity. We present a new typing resolution score (TRS), based on the likelihood of self-match, that allows the systematic comparison of HLA typings across different methods, data sets and populations. We apply the TRS to chart improvement in HLA typing within the Be The Match Registry of the United States from the initiation of DNA-based HLA typing to the current state of high-resolution typing using next-generation sequencing technologies. In addition, we present a publicly available online tool for evaluation of any given HLA typing. This TRS objectively evaluates HLA typing methods and can help define standards for acceptable recruitment HLA typing. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

A comparison of 12 algorithms for matching on the propensity score.

PubMed

Austin, Peter C

2014-03-15

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

A comparison of 12 algorithms for matching on the propensity score

PubMed Central

Austin, Peter C

2014-01-01

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:24123228

Assessing covariate balance when using the generalized propensity score with quantitative or continuous exposures.

PubMed

Austin, Peter C

2018-01-01

Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures (e.g., active treatment vs. control). The generalized propensity score is an extension of the propensity score for use with quantitative exposures (e.g., dose or quantity of medication, income, years of education). A crucial component of any propensity score analysis is that of balance assessment. This entails assessing the degree to which conditioning on the propensity score (via matching, weighting, or stratification) has balanced measured baseline covariates between exposure groups. Methods for balance assessment have been well described and are frequently implemented when using the propensity score with binary exposures. However, there is a paucity of information on how to assess baseline covariate balance when using the generalized propensity score. We describe how methods based on the standardized difference can be adapted for use with quantitative exposures when using the generalized propensity score. We also describe a method based on assessing the correlation between the quantitative exposure and each covariate in the sample when weighted using generalized propensity score -based weights. We conducted a series of Monte Carlo simulations to evaluate the performance of these methods. We also compared two different methods of estimating the generalized propensity score: ordinary least squared regression and the covariate balancing propensity score method. We illustrate the application of these methods using data on patients hospitalized with a heart attack with the quantitative exposure being creatinine level.

Brain medical image diagnosis based on corners with importance-values.

PubMed

Gao, Linlin; Pan, Haiwei; Li, Qing; Xie, Xiaoqin; Zhang, Zhiqiang; Han, Jinming; Zhai, Xiao

2017-11-21

Brain disorders are one of the top causes of human death. Generally, neurologists analyze brain medical images for diagnosis. In the image analysis field, corners are one of the most important features, which makes corner detection and matching studies essential. However, existing corner detection studies do not consider the domain information of brain. This leads to many useless corners and the loss of significant information. Regarding corner matching, the uncertainty and structure of brain are not employed in existing methods. Moreover, most corner matching studies are used for 3D image registration. They are inapplicable for 2D brain image diagnosis because of the different mechanisms. To address these problems, we propose a novel corner-based brain medical image classification method. Specifically, we automatically extract multilayer texture images (MTIs) which embody diagnostic information from neurologists. Moreover, we present a corner matching method utilizing the uncertainty and structure of brain medical images and a bipartite graph model. Finally, we propose a similarity calculation method for diagnosis. Brain CT and MRI image sets are utilized to evaluate the proposed method. First, classifiers are trained in N-fold cross-validation analysis to produce the best θ and K. Then independent brain image sets are tested to evaluate the classifiers. Moreover, the classifiers are also compared with advanced brain image classification studies. For the brain CT image set, the proposed classifier outperforms the comparison methods by at least 8% on accuracy and 2.4% on F1-score. Regarding the brain MRI image set, the proposed classifier is superior to the comparison methods by more than 7.3% on accuracy and 4.9% on F1-score. Results also demonstrate that the proposed method is robust to different intensity ranges of brain medical image. In this study, we develop a robust corner-based brain medical image classifier. Specifically, we propose a corner detection method utilizing the diagnostic information from neurologists and a corner matching method based on the uncertainty and structure of brain medical images. Additionally, we present a similarity calculation method for brain image classification. Experimental results on two brain image sets show the proposed corner-based brain medical image classifier outperforms the state-of-the-art studies.

Validation of a Pediatric Early Warning Score in Hospitalized Pediatric Oncology and Hematopoietic Stem Cell Transplant Patients.

PubMed

Agulnik, Asya; Forbes, Peter W; Stenquist, Nicole; Rodriguez-Galindo, Carlos; Kleinman, Monica

2016-04-01

To evaluate the correlation of a Pediatric Early Warning Score with unplanned transfer to the PICU in hospitalized oncology and hematopoietic stem cell transplant patients. We performed a retrospective matched case-control study, comparing the highest documented Pediatric Early Warning Score within 24 hours prior to unplanned PICU transfers in hospitalized pediatric oncology and hematopoietic stem cell transplant patients between September 2011 and December 2013. Controls were patients who remained on the inpatient unit and were matched 2:1 using age, condition (oncology vs hematopoietic stem cell transplant), and length of hospital stay. Pediatric Early Warning Scores were documented by nursing staff at least every 4 hours as part of routine care. Need for transfer was determined by a PICU physician called to evaluate the patient. A large tertiary/quaternary free-standing academic children's hospital. One hundred ten hospitalized pediatric oncology patients (42 oncology, 68 hematopoietic stem cell transplant) requiring unplanned PICU transfer and 220 matched controls. None. Using the highest score in the 24 hours prior to transfer for cases and a matched time period for controls, the Pediatric Early Warning Score was highly correlated with the need for PICU transfer overall (area under the receiver operating characteristic = 0.96), and in the oncology and hematopoietic stem cell transplant groups individually (area under the receiver operating characteristic = 0.95 and 0.96, respectively). The difference in Pediatric Early Warning Score results between the cases and controls was noted as early as 24 hours prior to PICU admission. Seventeen patients died (15.4%). Patients with higher Pediatric Early Warning Scores prior to transfer had increased PICU mortality (p = 0.028) and length of stay (p = 0.004). We demonstrate that our institution's Pediatric Early Warning Score is highly correlated with the need for unplanned PICU transfer in hospitalized oncology and hematopoietic stem cell transplant patients. Furthermore, we found an association between higher scores and PICU mortality. This is the first validation of a Pediatric Early Warning Score specific to the pediatric oncology and hematopoietic stem cell transplant populations, and supports the use of Pediatric Early Warning Scores as a method of early identification of clinical deterioration in this high-risk population.

Patients with type 2 diabetes benefit from primary care-based disease management: a propensity score matched survival time analysis.

PubMed

Drabik, Anna; Büscher, Guido; Thomas, Karsten; Graf, Christian; Müller, Dirk; Stock, Stephanie

2012-08-01

This study aimed to assess the impact of a nationwide German diabetes mellitus disease management program (DMP) on survival time and costs in comparison to routine care. The authors conducted a retrospective observational cohort study using routine administration data from Germany's largest sickness fund to identify insured suffering from diabetes in 2002. A total of 95,443 insured with type 2 diabetes mellitus who were born before January 1, 1962 met the defined inclusion criteria, resulting in 19,888 pairs of DMP participants and nonparticipants matched for socioeconomic and health status using propensity score matching methods. This is the first time propensity score matching has been used to evaluate a survival benefit of DMPs. In the time frame analyzed (3 years), mean survival time for the DMP group was 1045 days vs. 985 days for the routine care group (P<0.001). Mean daily hospital and total costs (including DMP administration and medical costs) were lower for the DMP group in the case of deceased insureds (92€ vs. 139€ and 122€ vs. 169€, respectively) as well as for censored observations (6€ vs. 7€ and 12.9€ vs. 13.4€, respectively). Mean daily drug costs were slightly lower for deceased insured in the DMP group (difference 0.6€), while no identifiable difference was found for censored observations. In this study, insured who were enrolled in a DMP for diabetes mellitus in the German Statutory Health Insurance showed a significant benefit in survival time. They also incurred lower costs compared to propensity score matched insured in routine care.

Query-by-example surgical activity detection.

PubMed

Gao, Yixin; Vedula, S Swaroop; Lee, Gyusung I; Lee, Mija R; Khudanpur, Sanjeev; Hager, Gregory D

2016-06-01

Easy acquisition of surgical data opens many opportunities to automate skill evaluation and teaching. Current technology to search tool motion data for surgical activity segments of interest is limited by the need for manual pre-processing, which can be prohibitive at scale. We developed a content-based information retrieval method, query-by-example (QBE), to automatically detect activity segments within surgical data recordings of long duration that match a query. The example segment of interest (query) and the surgical data recording (target trial) are time series of kinematics. Our approach includes an unsupervised feature learning module using a stacked denoising autoencoder (SDAE), two scoring modules based on asymmetric subsequence dynamic time warping (AS-DTW) and template matching, respectively, and a detection module. A distance matrix of the query against the trial is computed using the SDAE features, followed by AS-DTW combined with template scoring, to generate a ranked list of candidate subsequences (substrings). To evaluate the quality of the ranked list against the ground-truth, thresholding conventional DTW distances and bipartite matching are applied. We computed the recall, precision, F1-score, and a Jaccard index-based score on three experimental setups. We evaluated our QBE method using a suture throw maneuver as the query, on two tool motion datasets (JIGSAWS and MISTIC-SL) captured in a training laboratory. We observed a recall of 93, 90 and 87 % and a precision of 93, 91, and 88 % with same surgeon same trial (SSST), same surgeon different trial (SSDT) and different surgeon (DS) experiment setups on JIGSAWS, and a recall of 87, 81 and 75 % and a precision of 72, 61, and 53 % with SSST, SSDT and DS experiment setups on MISTIC-SL, respectively. We developed a novel, content-based information retrieval method to automatically detect multiple instances of an activity within long surgical recordings. Our method demonstrated adequate recall across different complexity datasets and experimental conditions.

SU-C-207B-07: Deep Convolutional Neural Network Image Matching for Ultrasound Guidance in Radiotherapy

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

Zhu, N; Najafi, M; Hancock, S

Purpose: Robust matching of ultrasound images is a challenging problem as images of the same anatomy often present non-trivial differences. This poses an obstacle for ultrasound guidance in radiotherapy. Thus our objective is to overcome this obstacle by designing and evaluating an image blocks matching framework based on a two channel deep convolutional neural network. Methods: We extend to 3D an algorithmic structure previously introduced for 2D image feature learning [1]. To obtain the similarity between two 3D image blocks A and B, the 3D image blocks are divided into 2D patches Ai and Bi. The similarity is then calculatedmore » as the average similarity score of Ai and Bi. The neural network was then trained with public non-medical image pairs, and subsequently evaluated on ultrasound image blocks for the following scenarios: (S1) same image blocks with/without shifts (A and A-shift-x); (S2) non-related random block pairs; (S3) ground truth registration matched pairs of different ultrasound images with/without shifts (A-i and A-reg-i-shift-x). Results: For S1 the similarity scores of A and A-shift-x were 32.63, 18.38, 12.95, 9.23, 2.15 and 0.43 for x=ranging from 0 mm to 10 mm in 2 mm increments. For S2 the average similarity score for non-related block pairs was −1.15. For S3 the average similarity score of ground truth registration matched blocks A-i and A-reg-i-shift-0 (1≤i≤5) was 12.37. After translating A-reg-i-shift-0 by 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm, the average similarity scores of A-i and A-reg-i-shift-x were 11.04, 8.42, 4.56, 2.27, and 0.29 respectively. Conclusion: The proposed method correctly assigns highest similarity to corresponding 3D ultrasound image blocks despite differences in image content and thus can form the basis for ultrasound image registration and tracking.[1] Zagoruyko, Komodakis, “Learning to compare image patches via convolutional neural networks', IEEE CVPR 2015,pp.4353–4361.« less

Does Matching Quality Matter in Mode Comparison Studies?

ERIC Educational Resources Information Center

Zeng, Ji; Yin, Ping; Shedden, Kerby A.

2015-01-01

This article provides a brief overview and comparison of three matching approaches in forming comparable groups for a study comparing test administration modes (i.e., computer-based tests [CBT] and paper-and-pencil tests [PPT]): (a) a propensity score matching approach proposed in this article, (b) the propensity score matching approach used by…

Approximate matching of regular expressions.

PubMed

Myers, E W; Miller, W

1989-01-01

Given a sequence A and regular expression R, the approximate regular expression matching problem is to find a sequence matching R whose optimal alignment with A is the highest scoring of all such sequences. This paper develops an algorithm to solve the problem in time O(MN), where M and N are the lengths of A and R. Thus, the time requirement is asymptotically no worse than for the simpler problem of aligning two fixed sequences. Our method is superior to an earlier algorithm by Wagner and Seiferas in several ways. First, it treats real-valued costs, in addition to integer costs, with no loss of asymptotic efficiency. Second, it requires only O(N) space to deliver just the score of the best alignment. Finally, its structure permits implementation techniques that make it extremely fast in practice. We extend the method to accommodate gap penalties, as required for typical applications in molecular biology, and further refine it to search for sub-strings of A that strongly align with a sequence in R, as required for typical data base searches. We also show how to deliver an optimal alignment between A and R in only O(N + log M) space using O(MN log M) time. Finally, an O(MN(M + N) + N2log N) time algorithm is presented for alignment scoring schemes where the cost of a gap is an arbitrary increasing function of its length.

Prognostic score–based balance measures for propensity score methods in comparative effectiveness research

PubMed Central

Stuart, Elizabeth A.; Lee, Brian K.; Leacy, Finbarr P.

2013-01-01

Objective Examining covariate balance is the prescribed method for determining when propensity score methods are successful at reducing bias. This study assessed the performance of various balance measures, including a proposed balance measure based on the prognostic score (also known as the disease-risk score), to determine which balance measures best correlate with bias in the treatment effect estimate. Study Design and Setting The correlations of multiple common balance measures with bias in the treatment effect estimate produced by weighting by the odds, subclassification on the propensity score, and full matching on the propensity score were calculated. Simulated data were used, based on realistic data settings. Settings included both continuous and binary covariates and continuous covariates only. Results The standardized mean difference in prognostic scores, the mean standardized mean difference, and the mean t-statistic all had high correlations with bias in the effect estimate. Overall, prognostic scores displayed the highest correlations of all the balance measures considered. Prognostic score measure performance was generally not affected by model misspecification and performed well under a variety of scenarios. Conclusion Researchers should consider using prognostic score–based balance measures for assessing the performance of propensity score methods for reducing bias in non-experimental studies. PMID:23849158

Performance indicators related to points scoring and winning in international rugby sevens.

PubMed

Higham, Dean G; Hopkins, Will G; Pyne, David B; Anson, Judith M

2014-05-01

Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team's points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key pointsSuccessful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball.Selected performance indicators may be used to evaluate team performances and plan more effective tactical approaches to competition.There is greater match-to-match variability in performance indicator values within than between international rugby sevens teams.The priorities for a rugby sevens team's technical and tactical preparation should reflect the magnitudes of the relationships between performance indicators, points scoring and the likelihood of winning.

Performance Indicators Related to Points Scoring and Winning in International Rugby Sevens

PubMed Central

Higham, Dean G.; Hopkins, Will G.; Pyne, David B.; Anson, Judith M.

2014-01-01

Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team’s points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key points Successful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball. Selected performance indicators may be used to evaluate team performances and plan more effective tactical approaches to competition. There is greater match-to-match variability in performance indicator values within than between international rugby sevens teams. The priorities for a rugby sevens team’s technical and tactical preparation should reflect the magnitudes of the relationships between performance indicators, points scoring and the likelihood of winning. PMID:24790490

Can Palliative Home Care Reduce 30-Day Readmissions? Results of a Propensity Score Matched Cohort Study

PubMed Central

Ranganathan, Anjana; Dougherty, Meredith; Waite, David

2013-01-01

Abstract Objective This study examined the impact of palliative home nursing care on rates of hospital 30-day readmissions. Methods The electronic health record based retrospective cohort study was performed within home care and palliative home care programs. Participants were home care patients discharged from one of three urban teaching hospitals. Outcome measures were propensity score matched rates of hospital readmissions within 30 days of hospital discharge. Results Of 406 palliative home care patients, matches were identified for 392 (96%). Of 15,709 home care patients, 890 were used at least once as a match for palliative care patients, for a total final sample of 1282. Using the matched sample we calculated the average treatment effect for treated patients. In this sample, palliative care patients had a 30-day readmission probability of 9.1% compared to a probability of 17.4% in the home care group (mean ATT: 8.3%; 95% confidence interval [CI] 8.0%–8.6%). This effect persisted after adjustment for visit frequency. Conclusions Palliative home care may offer benefits to health systems by allowing patients to remain at home and thereby avoiding 30-day rehospitalizations. PMID:24007348

The impact of HLA matching on long-term transplant outcome after allogeneic hematopoietic stem cell transplantation for CLL: a retrospective study from the EBMT registry.

PubMed

Michallet, M; Sobh, M; Milligan, D; Morisset, S; Niederwieser, D; Koza, V; Ruutu, T; Russell, N H; Verdonck, L; Dhedin, N; Vitek, A; Boogaerts, M; Vindelov, L; Finke, J; Dubois, V; van Biezen, A; Brand, R; de Witte, T; Dreger, P

2010-10-01

We analyzed 368 chronic lymphocytic leukemia patients who underwent allogeneic hematopoietic stem cell transplantation reported to the EBMT registry between 1995 and 2007. There were 198 human leukocyte antigen (HLA)-identical siblings; among unrelated transplants, 31 were well matched in high resolution ('well matched' unrelated donor, WMUD), and 139 were mismatched (MM), including 30 matched in low resolution; 266 patients (72%) received reduced-intensity conditioning and 102 (28%) received standard. According to the EBMT risk score, 11% were in scores 1-3, 23% in score 4, 40% in score 5, 22% in score 6 and 4% in score 7. There was no difference in overall survival (OS) at 5 years between HLA-identical siblings (55% (48-64)) and WMUD (59% (41-84)), P=0.82. In contrast, OS was significantly worse for MM (37% (29-48) P=0.005) due to a significant excess of transplant-related mortality. Also OS worsened significantly when EBMT risk score increased. HLA matching had no significant impact on relapse (siblings: 24% (21-27); WMUD: 35% (26-44), P=0.11 and MM: 21% (18-24), P=0.81); alemtuzumab T-cell depletion and stem cell source (peripheral blood) were associated with an increased risk. Our findings support the use of WMUD as equivalent alternative to HLA-matched sibling donors for allogeneic HSCT in CLL, and justify the application of EBMT risk score in this disease.

Comparison of accuracies of an intraoral spectrophotometer and conventional visual method for shade matching using two shade guide systems.

PubMed

Parameswaran, Vidhya; Anilkumar, S; Lylajam, S; Rajesh, C; Narayan, Vivek

2016-01-01

This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both methods and effectiveness of two shade guides with either method. In the visual method, 10 examiners with normal color vision matched target control shade tabs taken from the two shade guides (VITAPAN Classical™ and VITAPAN 3D Master™) with other full sets of the respective shade guides. Each tab was matched 3 times to determine repeatability of visual examiners. The spectrophotometric shade matching was performed by two independent examiners using an intraoral spectrophotometer (VITA Easyshade™) with five repetitions for each tab. Results revealed that visual method had greater accuracy than the spectrophotometer. The spectrophotometer; however, exhibited significantly better interrater agreement as compared to the visual method. While VITAPAN Classical shade guide was more accurate with the spectrophotometer, VITAPAN 3D Master shade guide proved better with visual method. This in vitro study clearly delineates the advantages and limitations of both methods. There were significant differences between the methods with the visual method producing more accurate results than the spectrophotometric method. The spectrophotometer showed far better interrater agreement scores irrespective of the shade guide used. Even though visual shade matching is subjective, it is not inferior and should not be underrated. Judicious combination of both techniques is imperative to attain a successful and esthetic outcome.

Scoring System Prognostic of Outcome in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation for Myelodysplastic Syndrome

PubMed Central

Ahn, Kwang Woo; Hu, Zhen-Huan; Nishihori, Taiga; Malone, Adriana K.; Valcárcel, David; Grunwald, Michael R.; Bacher, Ulrike; Hamilton, Betty; Kharfan-Dabaja, Mohamed A.; Saad, Ayman; Cutler, Corey; Warlick, Erica; Reshef, Ran; Wirk, Baldeep Mona; Sabloff, Mitchell; Fasan, Omotayo; Gerds, Aaron; Marks, David; Olsson, Richard; Wood, William Allen; Costa, Luciano J.; Miller, Alan M.; Cortes, Jorge; Daly, Andrew; Kindwall-Keller, Tamila L.; Kamble, Rammurti; Rizzieri, David A.; Cahn, Jean-Yves; Gale, Robert Peter; William, Basem; Litzow, Mark; Wiernik, Peter H.; Liesveld, Jane; Savani, Bipin N.; Vij, Ravi; Ustun, Celalettin; Copelan, Edward; Popat, Uday; Kalaycio, Matt; Maziarz, Richard; Alyea, Edwin; Sobecks, Ron; Pavletic, Steven; Tallman, Martin; Saber, Wael

2016-01-01

Purpose To develop a system prognostic of outcome in those undergoing allogeneic hematopoietic cell transplantation (allo HCT) for myelodysplastic syndrome (MDS). Patients and Methods We examined 2,133 patients with MDS undergoing HLA-matched (n = 1,728) or -mismatched (n = 405) allo HCT from 2000 to 2012. We used a Cox multivariable model to identify factors prognostic of mortality in a training subset (n = 1,151) of the HLA-matched cohort. A weighted score using these factors was assigned to the remaining patients undergoing HLA-matched allo HCT (validation cohort; n = 577) as well as to patients undergoing HLA-mismatched allo HCT. Results Blood blasts greater than 3% (hazard ratio [HR], 1.41; 95% CI, 1.08 to 1.85), platelets 50 × 109/L or less at transplantation (HR, 1.37; 95% CI, 1.18 to 1.61), Karnofsky performance status less than 90% (HR, 1.25; 95% CI, 1.06 to 1.28), comprehensive cytogenetic risk score of poor or very poor (HR, 1.43; 95% CI, 1.14 to 1.80), and age 30 to 49 years (HR, 1.60; 95% CI, 1.09 to 2.35) were associated with increased hazard of death and assigned 1 point in the scoring system. Monosomal karyotype (HR, 2.01; 95% CI, 1.65 to 2.45) and age 50 years or older (HR, 1.93; 95% CI, 1.36 to 2.83) were assigned 2 points. The 3-year overall survival after transplantation in patients with low (0 to 1 points), intermediate (2 to 3), high (4 to 5) and very high (≥ 6) scores was 71% (95% CI, 58% to 85%), 49% (95% CI, 42% to 56%), 41% (95% CI, 31% to 51%), and 25% (95% CI, 4% to 46%), respectively (P < .001). Increasing score was predictive of increased relapse (P < .001) and treatment-related mortality (P < .001) in the HLA-matched set and relapse (P < .001) in the HLA-mismatched cohort. Conclusion The proposed system is prognostic of outcome in patients undergoing HLA-matched and -mismatched allo HCT for MDS. PMID:27044940

Linking management effectiveness indicators to observed effects of protected areas on fire occurrence in the Amazon rainforest.

PubMed

Nolte, Christoph; Agrawal, Arun

2013-02-01

Management-effectiveness scores are used widely by donors and implementers of conservation projects to prioritize, track, and evaluate investments in protected areas. However, there is little evidence that these scores actually reflect the capacity of protected areas to deliver conservation outcomes. We examined the relation between indicators of management effectiveness in protected areas and the effectiveness of protected areas in reducing fire occurrence in the Amazon rainforest. We used data collected with the Management Effectiveness Tracking Tool (METT) scorecard, adopted by some of the world's largest conservation organizations to track management characteristics believed to be crucial for protected-area effectiveness. We used the occurrence of forest fires from 2000 through 2010 as a measure of the effect of protected areas on undesired land-cover change in the Amazon basin. We used matching to compare the estimated effect of protected areas with low versus high METT scores on fire occurrence. We also estimated effects of individual protected areas on fire occurrence and explored the relation between these effects and METT scores. The relations between METT scores and effects of protected areas on fire occurrence were weak. Protected areas with higher METT scores in 2005 did not seem to have performed better than protected areas with lower METT scores at reducing fire occurrence over the last 10 years. Further research into the relations between management-effectiveness indicators and conservation outcomes in protected areas seems necessary, and our results show that the careful application of matching methods can be a suitable method for that purpose. ©2012 Society for Conservation Biology.

Case matching and the reduction of selection bias in quasi-experiments: The relative importance of pretest measures of outcome, of unreliable measurement, and of mode of data analysis.

PubMed

Cook, Thomas D; Steiner, Peter M

2010-03-01

In this article, we note the many ontological, epistemological, and methodological similarities between how Campbell and Rubin conceptualize causation. We then explore 3 differences in their written emphases about individual case matching in observational studies. We contend that (a) Campbell places greater emphasis than Rubin on the special role of pretest measures of outcome among matching variables; (b) Campbell is more explicitly concerned with unreliability in the covariates; and (c) for analyzing the outcome, only Rubin emphasizes the advantages of using propensity score over regression methods. To explore how well these 3 factors reduce bias, we reanalyze and review within-study comparisons that contrast experimental and statistically adjusted nonexperimental causal estimates from studies with the same target population and treatment content. In this context, the choice of covariates counts most for reducing selection bias, and the pretest usually plays a special role relative to all the other covariates considered singly. Unreliability in the covariates also influences bias reduction but by less. Furthermore, propensity score and regression methods produce comparable degrees of bias reduction, though these within-study comparisons may not have met the theoretically specified conditions most likely to produce differences due to analytic method.

Changes in pain and concurrent pain medication use following compounded topical analgesic treatment for chronic pain: 3- and 6-month follow-up results from the prospective, observational Optimizing Patient Experience and Response to Topical Analgesics study

PubMed Central

Gudin, Jeffrey A; Brennan, Michael J; Harris, E Dennis; Hurwitz, Peter L; Dietze, Derek T; Strader, James D

2017-01-01

Background Opioids and other controlled substances prescribed for chronic pain are associated with abuse, addiction, and death, prompting national initiatives to identify safe and effective pain management strategies including topical analgesics. Methods This prospective, observational study evaluated changes from baseline in overall mean severity and interference scores on the Brief Pain Inventory scale and the use of concurrent pain medications at 3- and 6-month follow-up assessments in chronic pain patients treated with topical analgesics. Changes in pain severity and interference and medication usage were compared between treated patients and unmatched and matched controls. Results The unmatched intervention group (unmatched-IG) included 631 patients who completed baseline and 3-month follow-up surveys (3-month unmatched-IG) and 158 who completed baseline and 6-month follow-up assessments (6-month unmatched-IG). Baseline and 3-month follow-up data were provided by 76 unmatched controls and 76 matched controls (3-month unmatched-CG and matched-CG), and 51 unmatched and 36 matched patients completed baseline and 6-month follow-up surveys (6-month unmatched-CG and matched-CG). Baseline demographic characteristics and mean pain severity and interference scores were similar between groups. There were statistically significant decreases from baseline in mean pain severity and interference scores within the 3- and 6-month unmatched-IG (all P<0.001). Significantly greater decreases in the mean change from baseline in pain severity and interference scores were evident for the 3- and 6-month unmatched-IG versus unmatched-CG (all P<0.001), with similar results when the 3- and 6-month matched-IG and matched-CG were compared. A higher percentage of the 3- and 6-month unmatched-IG and matched-IG de-escalated use of concurrent pain medications (all P<0.001), while significantly higher percentages of the unmatched-CG and matched-CG escalated medication use. Side effects were reported by <1% of the unmatched-IG. Conclusion Topical analgesics appear to be effective and safe for the treatment of chronic pain, with randomized controlled trials needed to confirm these findings. PMID:29042810

General Certificate of Secondary Education performance in very low birthweight infants

PubMed Central

Pharoah, P; Stevenson, C; West, C

2003-01-01

Aim: To compare children of very low birth weight with matched controls for their performance in the General Certificate of Secondary Education (GCSE). Methods: GCSE examination results of 167 children of birth weight ⩽1500 g attending mainstream schools and without clinical disability and 167 individually matched classroom controls were analysed. Results: In 143 instances, both children of a matched pair were entered for examination in one or more GCSE subjects. The total points score obtained was greater in the comparison group than in the index cases (difference between means 4.45: 95% CI 0.95 to 7.94; p = 0.01). The mean point score per examination subject was also significantly greater in the comparison group than in the index cases (mean of differences 0.43: 95% CI 0.12 to 0.73; p < 0.01). Conclusions: As the children were closely matched for school and several social variables, factors acting during fetal or early postnatal development of very low birthweight infants probably compromise performance in the GCSE examination to a greater extent than school or childhood social environmental factors. PMID:12651749

Hunting for unexpected post-translational modifications by spectral library searching with tier-wise scoring.

PubMed

Ma, Chun Wai Manson; Lam, Henry

2014-05-02

Discovering novel post-translational modifications (PTMs) to proteins and detecting specific modification sites on proteins is one of the last frontiers of proteomics. At present, hunting for post-translational modifications remains challenging in widely practiced shotgun proteomics workflows due to the typically low abundance of modified peptides and the greatly inflated search space as more potential mass shifts are considered by the search engines. Moreover, most popular search methods require that the user specifies the modification(s) for which to search; therefore, unexpected and novel PTMs will not be detected. Here a new algorithm is proposed to apply spectral library searching to the problem of open modification searches, namely, hunting for PTMs without prior knowledge of what PTMs are in the sample. The proposed tier-wise scoring method intelligently looks for unexpected PTMs by allowing mass-shifted peak matches but only when the number of matches found is deemed statistically significant. This allows the search engine to search for unexpected modifications while maintaining its ability to identify unmodified peptides effectively at the same time. The utility of the method is demonstrated using three different data sets, in which the numbers of spectrum identifications to both unmodified and modified peptides were substantially increased relative to a regular spectral library search as well as to another open modification spectral search method, pMatch.

Influence of light source, polarization, education, and training on shade matching quality.

PubMed

Clary, Jacqueline A; Ontiveros, Joe C; Cron, Stanley G; Paravina, Rade D

2016-07-01

Many factors influence the quality of shade selection, and isolating how significantly each of these factors influences results is difficult. The purpose of this in vitro study was to compare results of shade matching using handheld lights with or without a polarizing filter with results obtained using a professional viewing booth and to analyze the influence of education and training on shade selection outcome. A total of 96 third-year dental students (evaluators) were randomly separated into 4 groups. Each group was assigned 1 of 2 handheld shade-matching devices (lights) with or without a polarizing filter. Each group performed a shade matching exercise using the handheld light or a professional viewing booth. The exercise consisted of matching shade tabs placed in a typodont to a commercial shade guide. Each group repeated this procedure 4 times over a 9-week period. A lecture on shade matching was presented at the fifth week of the study, between "before" and "after" shade matching procedures. Shade matching scores with handheld lights (7.8) were higher than scores of shade matching with the viewing booth (7.2). The mean scores for before (7.2) and after (7.8) shade matching (with education and training in between) were significantly different. The combined effect of light and education and training improved the shade matching score by 1.2, from 6.8 in the before sessions using the viewing booth to 8.0 in the after sessions using handheld lights. A 21% increase in the number of evaluators who selected 1 of 4 best matches was recorded, 10% for handheld lights versus viewing booth after education and training versus before sessions and 11% between after sessions using handheld lights versus before sessions using viewing booth. Within the limits of the study, the shade matching scores with handheld lights were significantly better than the results obtained using a viewing booth (P<.01). Using a handheld light with or without a polarizing filter did not influence shade matching results. Mean shade matching scores were significantly better after education and training (P<.01). Light combined with education and training resulted in the greatest increase in shade matching quality. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Nonrigid synthetic aperture radar and optical image coregistration by combining local rigid transformations using a Kohonen network.

PubMed

Salehpour, Mehdi; Behrad, Alireza

2017-10-01

This study proposes a new algorithm for nonrigid coregistration of synthetic aperture radar (SAR) and optical images. The proposed algorithm employs point features extracted by the binary robust invariant scalable keypoints algorithm and a new method called weighted bidirectional matching for initial correspondence. To refine false matches, we assume that the transformation between SAR and optical images is locally rigid. This property is used to refine false matches by assigning scores to matched pairs and clustering local rigid transformations using a two-layer Kohonen network. Finally, the thin plate spline algorithm and mutual information are used for nonrigid coregistration of SAR and optical images.

Usefulness of a traction method using dental floss and a hemoclip for gastric endoscopic submucosal dissection: a propensity score matching analysis (with videos).

PubMed

Suzuki, Sho; Gotoda, Takuji; Kobayashi, Yoshiyuki; Kono, Shin; Iwatsuka, Kunio; Yagi-Kuwata, Naoko; Kusano, Chika; Fukuzawa, Masakatsu; Moriyasu, Fuminori

2016-02-01

Although endoscopic submucosal dissection (ESD) is a significant advancement in therapeutic endoscopy, it is a complicated technique and requires considerable expertise. In this exploratory study, we evaluated the efficacy of a simple traction method that uses dental floss and a hemoclip (DFC) and was developed to overcome the technical difficulties of ESD. In total, 238 early gastric cancers treated by ESD between May 2012 and December 2014 at Tokyo Medical University were retrospectively reviewed. Lesions treated by conventional ESD (n = 185) and by ESD with DFC (ESD-DFC) (n = 53) were compared. Multivariable analyses and propensity score matching were used to compensate for the differences in age, sex, resected specimen size, lesion location, lesion position, presence of ulceration, and operator level. The procedure time, rate of en bloc and complete resection, and rates of adverse events were evaluated between the 2 groups. Propensity score matching analysis created 43 matched pairs. Adjusted comparisons between ESD-DFC and conventional ESD showed similar treatment outcomes (en bloc resection rate: 97.7% vs 100%, P = .315; complete resection rate: 90.7% vs 95.3%, P = .397; perforation during ESD rate: 2.3% vs 2.3%, P = 1.000; post-ESD bleeding rate: 4.7% vs 4.7%, P = 1.000) but a significantly shorter procedure time for ESD-DFC (82.2 ± 79.5 minutes vs 118.2 ± 71.6 minutes, P = .002). ESD-DFC facilitated rapid ESD with good visualization and traction while ensuring high curability and safety. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Alternative Matching Scores to Control Type I Error of the Mantel-Haenszel Procedure for DIF in Dichotomously Scored Items Conforming to 3PL IRT and Nonparametric 4PBCB Models

ERIC Educational Resources Information Center

Monahan, Patrick O.; Ankenmann, Robert D.

2010-01-01

When the matching score is either less than perfectly reliable or not a sufficient statistic for determining latent proficiency in data conforming to item response theory (IRT) models, Type I error (TIE) inflation may occur for the Mantel-Haenszel (MH) procedure or any differential item functioning (DIF) procedure that matches on summed-item…

Sociodemographic Differences in the Association Between Obesity and Stress: A Propensity Score-Matched Analysis from the Korean National Health and Nutrition Examination Survey (KNHANES).

PubMed

Mak, Kwok-Kei; Kim, Dae-Hwan; Leigh, J Paul

2015-01-01

Few population-based studies have used an econometric approach to understand the association between two cancer risk factors, obesity and stress. This study investigated sociodemographic differences in the association between obesity and stress among Korean adults (6,546 men and 8,473 women). Data were drawn from the Korean National Health and Nutrition Examination Survey for 2008, 2009, and 2010. Ordered logistic regression models and propensity score matching methods were used to examine the associations between obesity and stress, stratified by gender and age groups. In women, the stress level of the obese group was found to be 27.6% higher than the nonobese group in the ordered logistic regression; the obesity effect on stress was statistically significant in the propensity score-matched analysis. Corresponding evidence for the effect of obesity on stress was lacking among men. Participants who were young, well-educated, and working were more likely to report stress. In Korea, obesity causes stress in women but not in men. Young women are susceptible to a disproportionate level of stress. More cancer prevention programs targeting young and obese women are encouraged in developed Asian countries.

Evaluating the effectiveness of flood damage mitigation measures by the application of Propensity Score Matching

NASA Astrophysics Data System (ADS)

Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

2014-01-01

The employment of damage mitigation measures by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called Propensity Score Matching to a survey of German households along along two major rivers major rivers that were flooded in 2002, 2005 and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly € 1700 to € 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between € 6700-14 000 of flood damage. This study concludes with four main recommendations regarding how to better apply Propensity Score Matching in future studies, and makes several policy recommendations.

Evaluating the effectiveness of flood damage mitigation measures by the application of propensity score matching

NASA Astrophysics Data System (ADS)

Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

2014-07-01

The employment of damage mitigation measures (DMMs) by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called propensity score matching (PSM) to a survey of German households along three major rivers that were flooded in 2002, 2005, and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly EUR 1700 to 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between EUR 6700 and 14 000 of flood damage per flood event. This study concludes with four main recommendations regarding how to better apply propensity score matching in future studies, and makes several policy recommendations.

Color-Matching and Blending-Effect of Universal Shade Bulk-Fill-Resin-Composite in Resin-Composite-Models and Natural Teeth.

PubMed

Abdelraouf, Rasha M; Habib, Nour A

2016-01-01

Objectives . To assess visually color-matching and blending-effect (BE) of a universal shade bulk-fill-resin-composite placed in resin-composite-models with different shades and cavity sizes and in natural teeth (extracted and patients' teeth). Materials and Methods . Resin-composite-discs (10 mm × 1 mm) were prepared of universal shade composite and resin-composite of shades: A1, A2, A3, A3.5, and A4. Spectrophotometric-color-measurement was performed to calculate color-difference (Δ E ) between the universal shade and shaded-resin-composites discs and determine their translucency-parameter (TP). Visual assessment was performed by seven normal-color-vision-observers to determine the color-matching between the universal shade and each shade, under Illuminant D65. Color-matching visual scoring (VS) values were expressed numerically (1-5): 1: mismatch/totally unacceptable, 2: Poor-Match/hardly acceptable, 3: Good-Match/acceptable, 4: Close-Match/small-difference, and 5: Exact-Match/no-color-difference. Occlusal cavities of different sizes were prepared in teeth-like resin-composite-models with shades A1, A2, A3, A3.5, and A4. The cavities were filled by the universal shade composite. The same scale was used to score color-matching between the fillings and composite-models. BE was calculated as difference in mean-visual-scores in models and that of discs. Extracted teeth with two different class I-cavity sizes as well as ten patients' lower posterior molars with occlusal caries were prepared, filled by universal shade composite, and assessed similarly. Results . In models, the universal shade composite showed close matching in the different cavity sizes and surrounding shades (4 ≤ VS < 5) (BE = 0.6-2.9 in small cavities and 0.5-2.8 in large cavities). In extracted teeth, there was good-to-close color-matching (VS = 3.7-4.4 in small cavities, BE = 2.5-3.2) (VS = 3-3.5, BE = 1.8-2.3 in large cavities). In patients' molars, the universal shade composite showed good-matching (VS = 3-3.3, BE = -0.9-2.1). Conclusions . Color-matching of universal shade resin-composite was satisfactory rather than perfect in patients' teeth.

Inspection of aeronautical mechanical parts with a pan-tilt-zoom camera: an approach guided by the computer-aided design model

NASA Astrophysics Data System (ADS)

Viana, Ilisio; Orteu, Jean-José; Cornille, Nicolas; Bugarin, Florian

2015-11-01

We focus on quality control of mechanical parts in aeronautical context using a single pan-tilt-zoom (PTZ) camera and a computer-aided design (CAD) model of the mechanical part. We use the CAD model to create a theoretical image of the element to be checked, which is further matched with the sensed image of the element to be inspected, using a graph theory-based approach. The matching is carried out in two stages. First, the two images are used to create two attributed graphs representing the primitives (ellipses and line segments) in the images. In the second stage, the graphs are matched using a similarity function built from the primitive parameters. The similarity scores of the matching are injected in the edges of a bipartite graph. A best-match-search procedure in the bipartite graph guarantees the uniqueness of the match solution. The method achieves promising performance in tests with synthetic data including missing elements, displaced elements, size changes, and combinations of these cases. The results open good prospects for using the method with realistic data.

Comparison of accuracies of an intraoral spectrophotometer and conventional visual method for shade matching using two shade guide systems

PubMed Central

Parameswaran, Vidhya; Anilkumar, S.; Lylajam, S.; Rajesh, C.; Narayan, Vivek

2016-01-01

Background and Objectives: This in vitro study compared the shade matching abilities of an intraoral spectrophotometer and the conventional visual method using two shade guides. The results of previous investigations between color perceived by human observers and color assessed by instruments have been inconclusive. The objectives were to determine accuracies and interrater agreement of both methods and effectiveness of two shade guides with either method. Methods: In the visual method, 10 examiners with normal color vision matched target control shade tabs taken from the two shade guides (VITAPAN Classical™ and VITAPAN 3D Master™) with other full sets of the respective shade guides. Each tab was matched 3 times to determine repeatability of visual examiners. The spectrophotometric shade matching was performed by two independent examiners using an intraoral spectrophotometer (VITA Easyshade™) with five repetitions for each tab. Results: Results revealed that visual method had greater accuracy than the spectrophotometer. The spectrophotometer; however, exhibited significantly better interrater agreement as compared to the visual method. While VITAPAN Classical shade guide was more accurate with the spectrophotometer, VITAPAN 3D Master shade guide proved better with visual method. Conclusion: This in vitro study clearly delineates the advantages and limitations of both methods. There were significant differences between the methods with the visual method producing more accurate results than the spectrophotometric method. The spectrophotometer showed far better interrater agreement scores irrespective of the shade guide used. Even though visual shade matching is subjective, it is not inferior and should not be underrated. Judicious combination of both techniques is imperative to attain a successful and esthetic outcome. PMID:27746599

Exploring Robust Methods for Evaluating Treatment and Comparison Groups in Chronic Care Management Programs

PubMed Central

Hamar, Brent; Bradley, Chastity; Gandy, William M.; Harrison, Patricia L.; Sidney, James A.; Coberley, Carter R.; Rula, Elizabeth Y.; Pope, James E.

2013-01-01

Abstract Evaluation of chronic care management (CCM) programs is necessary to determine the behavioral, clinical, and financial value of the programs. Financial outcomes of members who are exposed to interventions (treatment group) typically are compared to those not exposed (comparison group) in a quasi-experimental study design. However, because member assignment is not randomized, outcomes reported from these designs may be biased or inefficient if study groups are not comparable or balanced prior to analysis. Two matching techniques used to achieve balanced groups are Propensity Score Matching (PSM) and Coarsened Exact Matching (CEM). Unlike PSM, CEM has been shown to yield estimates of causal (program) effects that are lowest in variance and bias for any given sample size. The objective of this case study was to provide a comprehensive comparison of these 2 matching methods within an evaluation of a CCM program administered to a large health plan during a 2-year time period. Descriptive and statistical methods were used to assess the level of balance between comparison and treatment members pre matching. Compared with PSM, CEM retained more members, achieved better balance between matched members, and resulted in a statistically insignificant Wald test statistic for group aggregation. In terms of program performance, the results showed an overall higher medical cost savings among treatment members matched using CEM compared with those matched using PSM (-$25.57 versus -$19.78, respectively). Collectively, the results suggest CEM is a viable alternative, if not the most appropriate matching method, to apply when evaluating CCM program performance. (Population Health Management 2013;16:35–45) PMID:22788834

Exploring robust methods for evaluating treatment and comparison groups in chronic care management programs.

PubMed

Wells, Aaron R; Hamar, Brent; Bradley, Chastity; Gandy, William M; Harrison, Patricia L; Sidney, James A; Coberley, Carter R; Rula, Elizabeth Y; Pope, James E

2013-02-01

Evaluation of chronic care management (CCM) programs is necessary to determine the behavioral, clinical, and financial value of the programs. Financial outcomes of members who are exposed to interventions (treatment group) typically are compared to those not exposed (comparison group) in a quasi-experimental study design. However, because member assignment is not randomized, outcomes reported from these designs may be biased or inefficient if study groups are not comparable or balanced prior to analysis. Two matching techniques used to achieve balanced groups are Propensity Score Matching (PSM) and Coarsened Exact Matching (CEM). Unlike PSM, CEM has been shown to yield estimates of causal (program) effects that are lowest in variance and bias for any given sample size. The objective of this case study was to provide a comprehensive comparison of these 2 matching methods within an evaluation of a CCM program administered to a large health plan during a 2-year time period. Descriptive and statistical methods were used to assess the level of balance between comparison and treatment members pre matching. Compared with PSM, CEM retained more members, achieved better balance between matched members, and resulted in a statistically insignificant Wald test statistic for group aggregation. In terms of program performance, the results showed an overall higher medical cost savings among treatment members matched using CEM compared with those matched using PSM (-$25.57 versus -$19.78, respectively). Collectively, the results suggest CEM is a viable alternative, if not the most appropriate matching method, to apply when evaluating CCM program performance.

GOSAP: Gene Ontology-Based Semantic Alignment of Biological Pathways.

PubMed

Gamalielsson, Jonas; Olsson, Bjorn

2008-01-01

We present a new method for semantic comparison of biological pathways, aiming to discover evolutionary conservation of pathways between species. Our method uses all three sub-ontologies of Gene Ontology (GO) and a measure of semantic similarity to calculate match scores between gene products. These scores are used for finding local pairwise pathway alignments. This approach has the advantage of being applicable to all types of pathways where nodes are gene products, e.g., regulatory pathways, signalling pathways and metabolic enzyme-to-enzyme pathways. We demonstrate the usefulness of the method using regulatory and metabolic pathways from E. coli and S. cerevisiae as examples.

Drawing causal inferences using propensity scores: a practical guide for community psychologists.

PubMed

Lanza, Stephanie T; Moore, Julia E; Butera, Nicole M

2013-12-01

Confounding present in observational data impede community psychologists' ability to draw causal inferences. This paper describes propensity score methods as a conceptually straightforward approach to drawing causal inferences from observational data. A step-by-step demonstration of three propensity score methods-weighting, matching, and subclassification-is presented in the context of an empirical examination of the causal effect of preschool experiences (Head Start vs. parental care) on reading development in kindergarten. Although the unadjusted population estimate indicated that children with parental care had substantially higher reading scores than children who attended Head Start, all propensity score adjustments reduce the size of this overall causal effect by more than half. The causal effect was also defined and estimated among children who attended Head Start. Results provide no evidence for improved reading if those children had instead received parental care. We carefully define different causal effects and discuss their respective policy implications, summarize advantages and limitations of each propensity score method, and provide SAS and R syntax so that community psychologists may conduct causal inference in their own research.

Drawing Causal Inferences Using Propensity Scores: A Practical Guide for Community Psychologists

PubMed Central

Lanza, Stephanie T.; Moore, Julia E.; Butera, Nicole M.

2014-01-01

Confounding present in observational data impede community psychologists’ ability to draw causal inferences. This paper describes propensity score methods as a conceptually straightforward approach to drawing causal inferences from observational data. A step-by-step demonstration of three propensity score methods – weighting, matching, and subclassification – is presented in the context of an empirical examination of the causal effect of preschool experiences (Head Start vs. parental care) on reading development in kindergarten. Although the unadjusted population estimate indicated that children with parental care had substantially higher reading scores than children who attended Head Start, all propensity score adjustments reduce the size of this overall causal effect by more than half. The causal effect was also defined and estimated among children who attended Head Start. Results provide no evidence for improved reading if those children had instead received parental care. We carefully define different causal effects and discuss their respective policy implications, summarize advantages and limitations of each propensity score method, and provide SAS and R syntax so that community psychologists may conduct causal inference in their own research. PMID:24185755

The Network Structure of Human Personality According to the NEO-PI-R: Matching Network Community Structure to Factor Structure

PubMed Central

Goekoop, Rutger; Goekoop, Jaap G.; Scholte, H. Steven

2012-01-01

Introduction Human personality is described preferentially in terms of factors (dimensions) found using factor analysis. An alternative and highly related method is network analysis, which may have several advantages over factor analytic methods. Aim To directly compare the ability of network community detection (NCD) and principal component factor analysis (PCA) to examine modularity in multidimensional datasets such as the neuroticism-extraversion-openness personality inventory revised (NEO-PI-R). Methods 434 healthy subjects were tested on the NEO-PI-R. PCA was performed to extract factor structures (FS) of the current dataset using both item scores and facet scores. Correlational network graphs were constructed from univariate correlation matrices of interactions between both items and facets. These networks were pruned in a link-by-link fashion while calculating the network community structure (NCS) of each resulting network using the Wakita Tsurumi clustering algorithm. NCSs were matched against FS and networks of best matches were kept for further analysis. Results At facet level, NCS showed a best match (96.2%) with a ‘confirmatory’ 5-FS. At item level, NCS showed a best match (80%) with the standard 5-FS and involved a total of 6 network clusters. Lesser matches were found with ‘confirmatory’ 5-FS and ‘exploratory’ 6-FS of the current dataset. Network analysis did not identify facets as a separate level of organization in between items and clusters. A small-world network structure was found in both item- and facet level networks. Conclusion We present the first optimized network graph of personality traits according to the NEO-PI-R: a ‘Personality Web’. Such a web may represent the possible routes that subjects can take during personality development. NCD outperforms PCA by producing plausible modularity at item level in non-standard datasets, and can identify the key roles of individual items and clusters in the network. PMID:23284713

Association between dietary patterns and metabolic syndrome in Chinese adults: a propensity score-matched case-control study.

PubMed

Xia, Yang; Gu, Yeqing; Yu, Fei; Zhang, Qing; Liu, Li; Meng, Ge; Wu, Hongmei; Du, Huanmin; Shi, Hongbin; Guo, Xiaoyan; Liu, Xing; Li, Chunlei; Han, Peipei; Dong, Renwei; Wang, Xiuyang; Bao, Xue; Su, Qian; Fang, Liyun; Liu, Fangfang; Yang, Huijun; Kang, Li; Ma, Yixuan; Yu, Bin; Sun, Shaomei; Wang, Xing; Zhou, Ming; Jia, Qiyu; Guo, Qi; Wu, Yuntang; Song, Kun; Huang, Guowei; Wang, Guolin; Niu, Kaijun

2016-10-06

Previous studies indicated that dietary patterns were associated with metabolic syndrome (MS), but little is known in Chinese. We design this case-control study to evaluate the associations between dietary patterns and MS in Chinese adults. In this study, 1492 participants with MS were matched with 1492 controls using the 1:1 ratio propensity score matching methods. Dietary intake was assessed using a valid self-administered food frequency questionnaire, and MS was defined in accordance with the criteria of the American Heart Association scientific statement of 2009. Higher scores for the high-protein/cholesterol pattern were associated with higher prevalence of MS. Compared with the participants in the lowest quartile, the odds ratio (OR) for the extreme quartile was 1.36 (95% confidence interval (CI), 1.10-1.68) and the P for trend <0.01 after adjusted for the other two dietary pattern scores. We also found a moderate consumption of the balanced pattern was associated with the lowest prevalence of MS. The ORs across quartiles of the balanced pattern were 1 (reference), 0.83 (95% CI, 0.68-1.02), 0.69 (95% CI, 0.56-0.85), and 0.84 (95% CI, 0.68-1.04) after adjustment. Our study demonstrates that there is a strong association between a diet rich in animal offal, animal blood, meat, and sausage and a higher prevalence of MS.

Does non-central nervous system tuberculosis increase the risk of ischemic stroke? A population-based propensity score-matched follow-up study.

PubMed

Wu, Chueh-Hung; Chen, Li-Sheng; Yen, Ming-Fang; Chiu, Yueh-Hsia; Fann, Ching-Yuan; Chen, Hsiu-Hsi; Pan, Shin-Liang

2014-01-01

Previous studies on the association between tuberculosis and the risk of developing ischemic stroke have generated inconsistent results. We therefore performed a population-based, propensity score-matched longitudinal follow-up study to investigate whether contracting non-central nervous system (CNS) tuberculosis leads to an increased risk of ischemic stroke. We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 5804 persons with at least three ambulatory visits in 2001 with the principal diagnosis of non-CNS tuberculosis were enrolled in the tuberculosis group. The non-tuberculosis group consisted of 5804, propensity score-matched subjects without tuberculosis. The three-year ischemic stroke-free survival rates for these 2 groups were estimated using the Kaplan-Meier method. The stratified Cox proportional hazards regression was used to estimate the effect of tuberculosis on the occurrence of ischemic stroke. During three-year follow-up, 176 subjects in the tuberculosis group (3.0%) and 207 in the non-tuberculosis group (3.6%) had ischemic stroke. The hazard ratio for developing ischemic stroke in the tuberculosis group was 0.92 compared to the non-tuberculosis group (95% confidence interval: 0.73-1.14, P = 0.4299). Non-CNS tuberculosis does not increase the risk of subsequent ischemic stroke.

Outcome of Early Initiation of Peritoneal Dialysis in Patients with End-Stage Renal Failure

PubMed Central

Oh, Kook-Hwan; Hwang, Young-Hwan; Cho, Jung-Hwa; Kim, Mira; Ju, Kyung Don; Joo, Kwon Wook; Kim, Dong Ki; Kim, Yon Su; Ahn, Curie

2012-01-01

Recent studies reported that early initiation of hemodialysis may increase mortality. However, studies that assessed the influence of early initiation of peritoneal dialysis (PD) yielded controversial results. In the present study, we evaluated the prognosis of early initiation of PD on the various outcomes of end stage renal failure patients by using propensity-score matching methods. Incident PD patients (n = 491) who started PD at SNU Hospital were enrolled. The patients were divided into 'early starters (n = 244)' and 'late starters (n = 247)' on the basis of the estimated glomerular filtration rate (eGFR) at the start of dialysis. The calculated propensity-score was used for one-to-one matching. After propensity-score-based matching (n = 136, for each group), no significant differences were observed in terms of all-cause mortality (P = 0.17), technique failure (P = 0.62), cardiovascular event (P = 0.96) and composite event (P = 0.86) between the early and late starters. Stratification analysis in the propensity-score quartiles (n = 491) exhibited no trend toward better or poorer survival in terms of all-cause mortality. In conclusion, early commencement of PD does not reduce the mortality risk and other outcomes. Although the recent guidelines suggest that initiation of dialysis at higher eGFR, physicians should not determine the time to initiate PD therapy simply rely on the eGFR alone. PMID:22323864

Surgical Treatment of Combined Posterior Root Tears of the Lateral Meniscus and ACL Tears

PubMed Central

Pan, Fengyu; Hua, Shan; Ma, Zhuang

2015-01-01

Background The treatment of anterior cruciate ligament (ACL) rupture complicated with posterior lateral meniscus root (PLMR) tears remains controversial. The goal of this study was to evaluate clinical outcomes of PLMR tear refixation versus left untreated at the time of reconstruction. Material/Methods From August 2001 to January 2012, 31 patients who undergone repair of PLMR tears were evaluated and compared with a matched control group with untreated PLMR tears. Clinical evaluation consisted of the Lysholm scale, subjective International Knee Documentation Committee (IKDC) questionnaires, and radiographic evaluation with MRI. Results Regarding to the Lysholm score and the subjective questionnaire score, there were no statistical difference between the 2 groups. However, patients after operative treatment reach higher functional scores and lower rates of osteoarthritis (normal: group A, 80%, and group B, 48%, respectively) with statistical significance (P<0.05) compared to the matched control group. Conclusions Surgical and conservative treatment of the PLMR can both effectively improve knee function. However, a tendency towards higher functional scores and lower rates of osteoarthritis for patients with operative treatment was observed. PMID:25959903

Which Propensity Score Method Best Reduces Confounder Imbalance? An Example From a Retrospective Evaluation of a Childhood Obesity Intervention.

PubMed

Schroeder, Krista; Jia, Haomiao; Smaldone, Arlene

Propensity score (PS) methods are increasingly being employed by researchers to reduce bias arising from confounder imbalance when using observational data to examine intervention effects. The purpose of this study was to examine PS theory and methodology and compare application of three PS methods (matching, stratification, weighting) to determine which best improves confounder balance. Baseline characteristics of a sample of 20,518 school-aged children with severe obesity (of whom 1,054 received an obesity intervention) were assessed prior to PS application. Three PS methods were then applied to the data to determine which showed the greatest improvement in confounder balance between the intervention and control group. The effect of each PS method on the outcome variable-body mass index percentile change at one year-was also examined. SAS 9.4 and Comprehensive Meta-analysis statistical software were used for analyses. Prior to PS adjustment, the intervention and control groups differed significantly on seven of 11 potential confounders. PS matching removed all differences. PS stratification and weighting both removed one difference but created two new differences. Sensitivity analyses did not change these results. Body mass index percentile at 1 year decreased in both groups. The size of the decrease was smaller in the intervention group, and the estimate of the decrease varied by PS method. Selection of a PS method should be guided by insight from statistical theory and simulation experiments, in addition to observed improvement in confounder balance. For this data set, PS matching worked best to correct confounder imbalance. Because each method varied in correcting confounder imbalance, we recommend that multiple PS methods be compared for ability to improve confounder balance before implementation in evaluating treatment effects in observational data.

Qualitative evaluations and comparisons of six night-vision colorization methods

NASA Astrophysics Data System (ADS)

Zheng, Yufeng; Reese, Kristopher; Blasch, Erik; McManamon, Paul

2013-05-01

Current multispectral night vision (NV) colorization techniques can manipulate images to produce colorized images that closely resemble natural scenes. The colorized NV images can enhance human perception by improving observer object classification and reaction times especially for low light conditions. This paper focuses on the qualitative (subjective) evaluations and comparisons of six NV colorization methods. The multispectral images include visible (Red-Green- Blue), near infrared (NIR), and long wave infrared (LWIR) images. The six colorization methods are channel-based color fusion (CBCF), statistic matching (SM), histogram matching (HM), joint-histogram matching (JHM), statistic matching then joint-histogram matching (SM-JHM), and the lookup table (LUT). Four categries of quality measurements are used for the qualitative evaluations, which are contrast, detail, colorfulness, and overall quality. The score of each measurement is rated from 1 to 3 scale to represent low, average, and high quality, respectively. Specifically, high contrast (of rated score 3) means an adequate level of brightness and contrast. The high detail represents high clarity of detailed contents while maintaining low artifacts. The high colorfulness preserves more natural colors (i.e., closely resembles the daylight image). Overall quality is determined from the NV image compared to the reference image. Nine sets of multispectral NV images were used in our experiments. For each set, the six colorized NV images (produced from NIR and LWIR images) are concurrently presented to users along with the reference color (RGB) image (taken at daytime). A total of 67 subjects passed a screening test ("Ishihara Color Blindness Test") and were asked to evaluate the 9-set colorized images. The experimental results showed the quality order of colorization methods from the best to the worst: CBCF < SM < SM-JHM < LUT < JHM < HM. It is anticipated that this work will provide a benchmark for NV colorization and for quantitative evaluation using an objective metric such as objective evaluation index (OEI).

Propensity Score Analysis in R: A Software Review

ERIC Educational Resources Information Center

Keller, Bryan; Tipton, Elizabeth

2016-01-01

In this article, we review four software packages for implementing propensity score analysis in R: "Matching, MatchIt, PSAgraphics," and "twang." After briefly discussing essential elements for propensity score analysis, we apply each package to a data set from the Early Childhood Longitudinal Study in order to estimate the…

Surface developmental dyslexia is as prevalent as phonological dyslexia when appropriate control groups are employed.

PubMed

Wybrow, Dean P; Hanley, J Richard

2015-01-01

Previous investigations of the incidence of developmental surface and phonological dyslexia using reading-age-matched control groups have identified many more phonological dyslexics (poor nonword reading relative to irregular-word reading) than surface dyslexics (poor irregular-word reading relative to nonword reading). However, because the measures that have been used to estimate reading age include irregular-word reading ability, they appear inappropriate for assessing the incidence of surface dyslexia. The current study used a novel method for generating control groups whose reading ability was matched to that of the dyslexic sample. The incidence of surface dyslexia was assessed by comparing dyslexic performance with that of a control group who were matched with the dyslexics on a test of nonword reading. The incidence of phonological dyslexia was assessed with reference to a control group who were matched with the dyslexics at irregular-word reading. These control groups led to the identification of an approximately equal number of children with surface and phonological dyslexia. It appeared that selecting control participants who were matched with dyslexics for reading age led to the recruitment of individuals with relatively high nonword reading scores relative to their irregular-word reading scores compared with other types of control group. The theoretical implications of these findings are discussed.

Establishing equivalence: methodological progress in group-matching design and analysis.

PubMed

Kover, Sara T; Atwoo, Amy K

2013-01-01

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and language in neurodevelopmental disorders, including autism spectrum disorder, Fragile X syndrome, Down syndrome, and Williams syndrome. The limitations of relying on p values to establish group equivalence are discussed in the context of other existing methods: equivalence tests, propensity scores, and regression-based analyses. Our primary recommendation for advancing research on intellectual and developmental disabilities is the use of descriptive indices of adequate group matching: effect sizes (i.e., standardized mean differences) and variance ratios.

Establishing Equivalence: Methodological Progress in Group-Matching Design and Analysis

PubMed Central

Kover, Sara T.; Atwood, Amy K.

2017-01-01

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs utilized in behavioral research on cognition and language in neurodevelopmental disorders, including autism spectrum disorder, fragile X syndrome, Down syndrome, and Williams syndrome. The limitations of relying on p-values to establish group equivalence are discussed in the context of other existing methods: equivalence tests, propensity scores, and regression-based analyses. Our primary recommendation for advancing research on intellectual and developmental disabilities is the use of descriptive indices of adequate group matching: effect sizes (i.e., standardized mean differences) and variance ratios. PMID:23301899

MSblender: A probabilistic approach for integrating peptide identifications from multiple database search engines.

PubMed

Kwon, Taejoon; Choi, Hyungwon; Vogel, Christine; Nesvizhskii, Alexey I; Marcotte, Edward M

2011-07-01

Shotgun proteomics using mass spectrometry is a powerful method for protein identification but suffers limited sensitivity in complex samples. Integrating peptide identifications from multiple database search engines is a promising strategy to increase the number of peptide identifications and reduce the volume of unassigned tandem mass spectra. Existing methods pool statistical significance scores such as p-values or posterior probabilities of peptide-spectrum matches (PSMs) from multiple search engines after high scoring peptides have been assigned to spectra, but these methods lack reliable control of identification error rates as data are integrated from different search engines. We developed a statistically coherent method for integrative analysis, termed MSblender. MSblender converts raw search scores from search engines into a probability score for every possible PSM and properly accounts for the correlation between search scores. The method reliably estimates false discovery rates and identifies more PSMs than any single search engine at the same false discovery rate. Increased identifications increment spectral counts for most proteins and allow quantification of proteins that would not have been quantified by individual search engines. We also demonstrate that enhanced quantification contributes to improve sensitivity in differential expression analyses.

MSblender: a probabilistic approach for integrating peptide identifications from multiple database search engines

PubMed Central

Kwon, Taejoon; Choi, Hyungwon; Vogel, Christine; Nesvizhskii, Alexey I.; Marcotte, Edward M.

2011-01-01

Shotgun proteomics using mass spectrometry is a powerful method for protein identification but suffers limited sensitivity in complex samples. Integrating peptide identifications from multiple database search engines is a promising strategy to increase the number of peptide identifications and reduce the volume of unassigned tandem mass spectra. Existing methods pool statistical significance scores such as p-values or posterior probabilities of peptide-spectrum matches (PSMs) from multiple search engines after high scoring peptides have been assigned to spectra, but these methods lack reliable control of identification error rates as data are integrated from different search engines. We developed a statistically coherent method for integrative analysis, termed MSblender. MSblender converts raw search scores from search engines into a probability score for all possible PSMs and properly accounts for the correlation between search scores. The method reliably estimates false discovery rates and identifies more PSMs than any single search engine at the same false discovery rate. Increased identifications increment spectral counts for all detected proteins and allow quantification of proteins that would not have been quantified by individual search engines. We also demonstrate that enhanced quantification contributes to improve sensitivity in differential expression analyses. PMID:21488652

Estimating the effect of a rare time-dependent treatment on the recurrent event rate.

PubMed

Smith, Abigail R; Zhu, Danting; Goodrich, Nathan P; Merion, Robert M; Schaubel, Douglas E

2018-05-30

In many observational studies, the objective is to estimate the effect of treatment or state-change on the recurrent event rate. If treatment is assigned after the start of follow-up, traditional methods (eg, adjustment for baseline-only covariates or fully conditional adjustment for time-dependent covariates) may give biased results. We propose a two-stage modeling approach using the method of sequential stratification to accurately estimate the effect of a time-dependent treatment on the recurrent event rate. At the first stage, we estimate the pretreatment recurrent event trajectory using a proportional rates model censored at the time of treatment. Prognostic scores are estimated from the linear predictor of this model and used to match treated patients to as yet untreated controls based on prognostic score at the time of treatment for the index patient. The final model is stratified on matched sets and compares the posttreatment recurrent event rate to the recurrent event rate of the matched controls. We demonstrate through simulation that bias due to dependent censoring is negligible, provided the treatment frequency is low, and we investigate a threshold at which correction for dependent censoring is needed. The method is applied to liver transplant (LT), where we estimate the effect of development of post-LT End Stage Renal Disease (ESRD) on rate of days hospitalized. Copyright © 2018 John Wiley & Sons, Ltd.

Probabilistic determination of probe locations from distance data

PubMed Central

Xu, Xiao-Ping; Slaughter, Brian D.; Volkmann, Niels

2013-01-01

Distance constraints, in principle, can be employed to determine information about the location of probes within a three-dimensional volume. Traditional methods for locating probes from distance constraints involve optimization of scoring functions that measure how well the probe location fits the distance data, exploring only a small subset of the scoring function landscape in the process. These methods are not guaranteed to find the global optimum and provide no means to relate the identified optimum to all other optima in scoring space. Here, we introduce a method for the location of probes from distance information that is based on probability calculus. This method allows exploration of the entire scoring space by directly combining probability functions representing the distance data and information about attachment sites. The approach is guaranteed to identify the global optimum and enables the derivation of confidence intervals for the probe location as well as statistical quantification of ambiguities. We apply the method to determine the location of a fluorescence probe using distances derived by FRET and show that the resulting location matches that independently derived by electron microscopy. PMID:23770585

Health Status of Patients With Chronic Obstructive Pulmonary Disease by Symptom Level.

PubMed

Marvel, Jessica; Yu, Tzy-Chyi; Wood, Robert; Higgins, Victoria S; Make, Barry J

2016-05-05

Background: Despite receiving treatment, patients with chronic obstructive pulmonary disease (COPD) often continue to experience symptoms that impact their health status. We determined the relationship between overall symptom burden and health status, and assessed the treatments patients were receiving. Methods: Data from 3 cross-sectional surveys of U.S. patients with COPD (2011-2013) were analyzed. Patients receiving inhaled COPD treatment for ≥3 months completed the COPD Assessment Test (CAT) symptom burden and respiratory health status measure, EuroQol 5-dimension (EQ-5D-3L) general health status questionnaire, and Jenkins Sleep Evaluation Questionnaire (JSEQ). CAT scores were used to identify high- (CAT ≥24) and low-symptom patients (CAT <24), who were matched using 1:1 propensity score matching with replacement. Match balance was assessed with standardized mean differences. EQ-5D-3L and JSEQ scores, and current treatment were compared between groups post-matching. Sensitivity was assessed with Rosenbaum bounds. Results: A total of 638 patients were included. Compared with low-symptom patients, high-symptom patients had worse health status and greater sleep disturbance by EQ-5D utility index (0.85 versus 0.71, respectively; p <0.0001) and JSEQ scores (3.73 versus 7.35, respectively; p <0.0001). High-symptom patients were prescribed single-maintenance bronchodilators ± inhaled corticosteroids (46.0%), triple therapy (40.5%), and short-acting therapy only (8.2%). Results were robust and insensitive to unobserved confounders. Conclusions: Increased COPD symptom burden is associated with worse general health status in patients receiving COPD treatment. High-symptom patients frequently received single inhaled medication. The results suggest that health care providers should monitor and tailor therapy, based on level of symptom burden to improve symptom control and health status.

Religiosity and the Impact of Religious Secondary Schooling

ERIC Educational Resources Information Center

Wadsworth, Allyssa A.; Walker, Jay K.

2017-01-01

Using a nationally representative longitudinal survey and incorporating propensity score matching methods, we follow secondary school students post-graduation to determine how Catholic and private religious schooling impacts religiosity. There is an established literature examining the Catholic school impact on collegiate and labor market…

Contactless and pose invariant biometric identification using hand surface.

PubMed

Kanhangad, Vivek; Kumar, Ajay; Zhang, David

2011-05-01

This paper presents a novel approach for hand matching that achieves significantly improved performance even in the presence of large hand pose variations. The proposed method utilizes a 3-D digitizer to simultaneously acquire intensity and range images of the user's hand presented to the system in an arbitrary pose. The approach involves determination of the orientation of the hand in 3-D space followed by pose normalization of the acquired 3-D and 2-D hand images. Multimodal (2-D as well as 3-D) palmprint and hand geometry features, which are simultaneously extracted from the user's pose normalized textured 3-D hand, are used for matching. Individual matching scores are then combined using a new dynamic fusion strategy. Our experimental results on the database of 114 subjects with significant pose variations yielded encouraging results. Consistent (across various hand features considered) performance improvement achieved with the pose correction demonstrates the usefulness of the proposed approach for hand based biometric systems with unconstrained and contact-free imaging. The experimental results also suggest that the dynamic fusion approach employed in this work helps to achieve performance improvement of 60% (in terms of EER) over the case when matching scores are combined using the weighted sum rule.

Self-Reported Wellness Profiles of Professional Australian Football Players During the Competition Phase of the Season.

PubMed

Gallo, Tania F; Cormack, Stuart J; Gabbett, Tim J; Lorenzen, Christian H

2017-02-01

Gallo, TF, Cormack, SJ, Gabbett, TJ, and Lorenzen, CH. Self-reported wellness profiles of professional Australian football players during the competition phase of the season. J Strength Cond Res 31(2): 495-502, 2017-With the prevalence of customized self-report measures in high-performance sport, and the incomplete understanding of athletes' perceived wellness in response to matches and training load, the objective of this study was to explore weekly wellness profiles within the context of the competitive season of professional Australian football. Internal match load, measured through the session-rating of perceived exertion method, match-to-match microcycle, stage of the season, and training load were included in multivariate linear models to determine their effect on weekly wellness profile (n = 1,835). There was a lower weekly training load on a 6-day microcycle compared with a 7-day and 8-day microcycle. Match load had no significant impact on weekly wellness profile, while there was an interaction between microcycle and days postmatch. There was a likely moderately lower wellness Z-score 1 day postmatch for an 8-day microcycle (mean; 95% confidence interval: -1.79; -2.02 to -1.56) compared with a 6-day (-1.19; -1.30 to -1.08) and 7-day (-1.22; -1.34 to -1.09) cycle (d; 95% confidence interval: -0.82; -1.3 to -0.36, -0.78; -1.3 to -0.28, respectively). The second half of the season saw a possibly small reduction in overall wellness Z-score than the first half of the season (0.22; 0.12-0.32). Finally, training load had no effect on wellness Z-score when controlled for days postmatch, microcycle, and stage of the season. These results provide information on the status of players in response to matches and fixed conditions. Knowing when wellness Z-score returns to baseline relative to the length of the microcycle may lead practitioners to prescribe the heaviest load of the week accordingly. Furthermore, wellness "red flags" should be made relative to the microcycles and stage of the season to determine an athlete's status relative to their typical weekly profile.

A-MUPS score to differentiate patients with somatic symptom disorder from those with medical disease for complaints of non-acute pain

PubMed Central

Suzuki, Shingo; Ohira, Yoshiyuki; Noda, Kazutaka; Ikusaka, Masatomi

2017-01-01

Purpose To develop a clinical score to discriminate patients with somatic symptom disorder (SSD) from those with medical disease (MD) for complaints of non-acute pain. Methods We retrospectively examined the clinical records of consecutive patients with pain for a duration of ≥1 month in our department from April 2003 to March 2015. We divided the subjects according to the diagnoses of definite SSD (as diagnosed and tracked by psychiatrists in our hospital), probable SSD (without evaluation by psychiatrists in our hospital), matched MD (randomly matched two patients by age, sex, and pain location for each definite SSD patient), unmatched MD, other mental disease, or functional somatic syndrome (FSS). We investigated eight clinical factors for definite SSD and matched MD, and developed a diagnostic score to identify SSD. We subsequently validated the model with cases of probable SSD and unmatched MD. Results The number of patients with definite SSD, probable SSD, matched MD, unmatched MD, other mental disease, and FSS was 104 (3.5%), 214 (7.3%), 197 (6.7%), 742 (25%), 708 (24%), and 978 (33%), respectively. In a conditional logistic regression analysis, the following five factors were included as independent predictors of SSD: Analgesics ineffective, Mental disorder history, Unclear provocative/palliative factors, Persistence without cessation, and Stress feelings/episodes (A-MUPS). The area under the receiver operating characteristic curve (AUC) of the model was 0.900 (95% CI: 0.864–0.937, p<0.001), and the McFadden’s pseudo-R-squared was 0.709. For internal validation, the AUC between probable SSD and unmatched MD was 0.930 (95% CI: 0.910–0.950, p<0.001). The prevalence and the likelihood ratio of SSD increased as the score increased. Conclusion The A-MUPS score was useful for discriminating patients with SSD from those with MD for complaints of non-acute pain, although external validation and refinement should be needed. PMID:28652807

A Probability Based Approach for the Allocation of Player Draft Selections in Australian Rules Football

PubMed Central

Anthony, Bedford; Schembri, Adrian J.

2006-01-01

Australian Rules Football, governed by the Australian Football League (AFL) is the most popular winter sport played in Australia. Like North American team based leagues such as the NFL, NBA and NHL, the AFL uses a draft system for rookie players to join a team’s list. The existing method of allocating draft selections in the AFL is simply based on the reverse order of each team’s finishing position for that season, with teams winning less than or equal to 5 regular season matches obtaining an additional early round priority draft pick. Much criticism has been levelled at the existing system since it rewards losing teams and does not encourage poorly performing teams to win matches once their season is effectively over. We propose a probability-based system that allocates a score based on teams that win ‘unimportant’ matches (akin to Carl Morris’ definition of importance). We base the calculation of ‘unimportance’ on the likelihood of a team making the final eight following each round of the season. We then investigate a variety of approaches based on the ‘unimportance’ measure to derive a score for ‘unimportant’ and unlikely wins. We explore derivatives of this system, compare past draft picks with those obtained under our system, and discuss the attractiveness of teams knowing the draft reward for winning each match in a season. Key Points Draft choices are allocated using a probabilistic approach that rewards teams for winning unimportant matches. The method is based upon Carl Morris’ Importance and probabilistic calculations of making the finals. The importance of a match is calculated probabilistically to arrive at a DScore. Higher DScores are weighted towards teams winning unimportant matches which in turn lead to higher draft selections. Provides an alternative to current draft systems that are based on ‘losing to win’. PMID:24357945

The CERAD Neuropsychological Assessment Battery Is Sensitive to Alcohol-Related Cognitive Deficiencies in Elderly Patients: A Retrospective Matched Case-Control Study.

PubMed

Kaufmann, Liane; Huber, Stefan; Mayer, Daniel; Moeller, Korbinian; Marksteiner, Josef

2018-04-01

Adverse effects of heavy drinking on cognition have frequently been reported. In the present study, we systematically examined for the first time whether clinical neuropsychological assessments may be sensitive to alcohol abuse in elderly patients with suspected minor neurocognitive disorder. A total of 144 elderly with and without alcohol abuse (each group n=72; mean age 66.7 years) were selected from a patient pool of n=738 by applying propensity score matching (a statistical method allowing to match participants in experimental and control group by balancing various covariates to reduce selection bias). Accordingly, study groups were almost perfectly matched regarding age, education, gender, and Mini Mental State Examination score. Neuropsychological performance was measured using the CERAD (Consortium to Establish a Registry for Alzheimer's Disease). Classification analyses (i.e., decision tree and boosted trees models) were conducted to examine whether CERAD variables or total score contributed to group classification. Decision tree models disclosed that groups could be reliably classified based on the CERAD variables "Word List Discriminability" (tapping verbal recognition memory, 64% classification accuracy) and "Trail Making Test A" (measuring visuo-motor speed, 59% classification accuracy). Boosted tree analyses further indicated the sensitivity of "Word List Recall" (measuring free verbal recall) for discriminating elderly with versus without a history of alcohol abuse. This indicates that specific CERAD variables seem to be sensitive to alcohol-related cognitive dysfunctions in elderly patients with suspected minor neurocognitive disorder. (JINS, 2018, 24, 360-371).

Effects of sugammadex vs. pyridostigmine-glycopyrrolate on post-operative nausea and vomiting: propensity score matching.

PubMed

Lee, O H; Choi, G J; Kang, H; Baek, C W; Jung, Y H; Woo, Y C; Oh, J; Park, Y H

2017-01-01

Sugammadex is a new agent that reverses neuromuscular blockade by aminosteroid neuromuscular blocker. This retrospective study compared the effects of sugammadex on post-operative nausea and vomiting (PONV) with those of a pyridostigmine-glycopyrrolate mixture. We reviewed the electronic medical records of 7179 patients who had received fentanyl-based, intravenous, patient-controlled analgesia (IV-PCA) at Chung-Ang University Hospital between January 1, 2010 and December 31, 2015. We categorized the patients into two groups on the basis of the type of reversal agent to neuromuscular blockade that was used: a traditional reversal agent (pyridostigmine-glycopyrrolate mixture; Group R; n = 7059) and sugammadex (Group S; n = 120). The propensity score matching method was then used to select 408 subjects in Group R and 115 subjects in Group S; on the basis of their covariates, these subjects were then matched with a counterpart in the other group. After propensity score matching, the two groups were well balanced with respect to all baseline covariates. In Group S, the numeric rating scale of nausea on day 0, as well as the number of patients who vomited on day 0, was lower than that in group R. Furthermore, Group S used fewer rescue antiemetics on day 0 and had a higher complete response on day 0. Sugammadex might be more beneficial for PONV compared to pyridostigmine-glycopyrrolate mixture for patients who have received opioid-based IV-PCA. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

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

Colbert, C.; Moles, D.R.

This paper reports that the authors developed for the Air Force the Mark VI Personal Identity Verifier (PIV) for controlling access to a fixed or mobile ICBM site, a computer terminal, or mainframe. The Mark VI records the digitized silhouettes of four fingers of each hand on an AT and T smart card. Like fingerprints, finger shapes, lengths, and widths constitute an unguessable biometric password. A Security Officer enrolls an authorized person who places each hand, in turn, on a backlighted panel. An overhead scanning camera records the right and left hand reference templates on the smart card. The Securitymore » Officer adds to the card: name, personal identification number (PIN), and access restrictions such as permitted days of the week, times of day, and doors. To gain access, cardowner inserts card into a reader slot and places either hand on the panel. Resulting access template is matched to the reference template by three sameness algorithms. The final match score is an average of 12 scores (each of the four fingers, matched for shape, length, and width), expressing the degree of sameness. (A perfect match would score 100.00.) The final match score is compared to a predetermined score (threshold), generating an accept or reject decision.« less

Application of constrained k-means clustering in ground motion simulation validation

NASA Astrophysics Data System (ADS)

Khoshnevis, N.; Taborda, R.

2017-12-01

The validation of ground motion synthetics has received increased attention over the last few years due to the advances in physics-based deterministic and hybrid simulation methods. Unlike for low frequency simulations (f ≤ 0.5 Hz), for which it has become reasonable to expect a good match between synthetics and data, in the case of high-frequency simulations (f ≥ 1 Hz) it is not possible to match results on a wiggle-by-wiggle basis. This is mostly due to the various complexities and uncertainties involved in earthquake ground motion modeling. Therefore, in order to compare synthetics with data we turn to different time series metrics, which are used as a means to characterize how the synthetics match the data on qualitative and statistical sense. In general, these metrics provide GOF scores that measure the level of similarity in the time and frequency domains. It is common for these scores to be scaled from 0 to 10, with 10 representing a perfect match. Although using individual metrics for particular applications is considered more adequate, there is no consensus or a unified method to classify the comparison between a set of synthetic and recorded seismograms when the various metrics offer different scores. We study the relationship among these metrics through a constrained k-means clustering approach. We define 4 hypothetical stations with scores 3, 5, 7, and 9 for all metrics. We put these stations in the category of cannot-link constraints. We generate the dataset through the validation of the results from a deterministic (physics-based) ground motion simulation for a moderate magnitude earthquake in the greater Los Angeles basin using three velocity models. The maximum frequency of the simulation is 4 Hz. The dataset involves over 300 stations and 11 metrics, or features, as they are understood in the clustering process, where the metrics form a multi-dimensional space. We address the high-dimensional feature effects with a subspace-clustering analysis, generate a final labeled dataset of stations, and discuss the within-class statistical characteristics of each metric. Labeling these stations is the first step towards developing a unified metric to evaluate ground motion simulations in an application-independent manner.

Quantifying and Interpreting Group Differences in Interest Profiles

ERIC Educational Resources Information Center

Armstrong, Patrick Ian; Fouad, Nadya A.; Rounds, James; Hubert, Lawrence

2010-01-01

Research on group differences in interests has often focused on structural hypotheses and mean-score differences in Holland's (1997) theory, with comparatively little research on basic interest measures. Group differences in interest profiles were examined using statistical methods for matching individuals with occupations, the C-index, Q…

Learning Institute In-Service Results.

ERIC Educational Resources Information Center

Fitzmaurice, Mercedes D.

This report compares the relative improvement in reading shown by students taught by teachers trained in the diagnostic/prescriptive approach with those taught by teachers using a conventional method. Subjects were 239 control and 261 experimental students, matched in basic demographic characteristics and in IQ scores, from grades four through…

A Quantitative Climate-Match Score for Risk-Assessment Screening of Reptile and Amphibian Introductions

NASA Astrophysics Data System (ADS)

van Wilgen, Nicola J.; Roura-Pascual, Núria; Richardson, David M.

2009-09-01

Assessing climatic suitability provides a good preliminary estimate of the invasive potential of a species to inform risk assessment. We examined two approaches for bioclimatic modeling for 67 reptile and amphibian species introduced to California and Florida. First, we modeled the worldwide distribution of the biomes found in the introduced range to highlight similar areas worldwide from which invaders might arise. Second, we modeled potentially suitable environments for species based on climatic factors in their native ranges, using three sources of distribution data. Performance of the three datasets and both approaches were compared for each species. Climate match was positively correlated with species establishment success (maximum predicted suitability in the introduced range was more strongly correlated with establishment success than mean suitability). Data assembled from the Global Amphibian Assessment through NatureServe provided the most accurate models for amphibians, while ecoregion data compiled by the World Wide Fund for Nature yielded models which described reptile climatic suitability better than available point-locality data. We present three methods of assigning a climate-match score for use in risk assessment using both the mean and maximum climatic suitabilities. Managers may choose to use different methods depending on the stringency of the assessment and the available data, facilitating higher resolution and accuracy for herpetofaunal risk assessment. Climate-matching has inherent limitations and other factors pertaining to ecological interactions and life-history traits must also be considered for thorough risk assessment.

Integrating image quality in 2nu-SVM biometric match score fusion.

PubMed

Vatsa, Mayank; Singh, Richa; Noore, Afzel

2007-10-01

This paper proposes an intelligent 2nu-support vector machine based match score fusion algorithm to improve the performance of face and iris recognition by integrating the quality of images. The proposed algorithm applies redundant discrete wavelet transform to evaluate the underlying linear and non-linear features present in the image. A composite quality score is computed to determine the extent of smoothness, sharpness, noise, and other pertinent features present in each subband of the image. The match score and the corresponding quality score of an image are fused using 2nu-support vector machine to improve the verification performance. The proposed algorithm is experimentally validated using the FERET face database and the CASIA iris database. The verification performance and statistical evaluation show that the proposed algorithm outperforms existing fusion algorithms.

A Comparison of Matched and Unmatched Orthopaedic Surgery Residency Applicants from 2006 to 2014: Data from the National Resident Matching Program.

PubMed

Schrock, John B; Kraeutler, Matthew J; Dayton, Michael R; McCarty, Eric C

2017-01-04

The Association of American Medical Colleges publishes residency match data and reports through the National Resident Matching Program (NRMP) every year. The purpose of this study was to analyze trends in orthopaedic surgery residency matching data and characteristics of successful applicants to counsel medical students with regard to their chances of matching. The annual reports of the NRMP were searched annually from 2006 to 2014 to determine the number of orthopaedic surgery residency positions available, the number of applicants, and the match rate among applicants. Comparisons were performed between matched applicants and unmatched applicants with regard to the number of contiguous ranks and distinct specialties, United States Medical Licensing Examination (USMLE) scores, number of research experiences and research products (abstracts, presentations, posters, publications), and proportion of Alpha Omega Alpha (AOA) Honor Medical Society members and students at a top-40, National Institutes of Health (NIH)-funded medical school. The number of orthopaedic surgery positions available and number of applicants increased at a mean rate of 9 positions and 65 applicants per year (p = 0.11). The mean number of contiguous ranks for U.S. senior medical students was 11.5 for those who matched and 5.5 for those who did not match (p < 0.0001). The USMLE scores for applicants who matched were significantly greater than for those who did not match in each category: Step-1 scores for U.S. seniors (p < 0.001) and independent applicants (p = 0.039), and Step-2 scores for U.S. seniors (p < 0.01) and independent applicants (p = 0.026). The mean number of research products was significantly greater for matched U.S. seniors compared with unmatched U.S. seniors (p = 0.035). A significantly higher proportion of matched U.S. seniors compared with unmatched U.S. seniors were AOA members and students at a top-40, NIH-funded medical school (both p < 0.0001). Successful applicants in the Match for orthopaedic surgery residency have higher USMLE Step-1 and 2 scores, number of research experiences and research products, and contiguous ranks. A higher proportion of successful applicants are AOA members and students at a top-40, NIH-funded medical school.

Empirical Implications of Matching Children with Specific Language Impairment to Children with Typical Development on Nonverbal IQ

ERIC Educational Resources Information Center

Earle, F. Sayako; Gallinat, Erica L.; Grela, Bernard G.; Lehto, Alexa; Spaulding, Tammie J.

2017-01-01

This study determined the effect of matching children with specific language impairment (SLI) and their peers with typical development (TD) for nonverbal IQ on the IQ test scores of the resultant groups. Studies published between January 2000 and May 2012 reporting standard nonverbal IQ scores for SLI and age-matched TD controls were categorized…

Computerized quantitative evaluation of mammographic accreditation phantom images

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

Lee, Yongbum; Tsai, Du-Yih; Shinohara, Norimitsu

2010-12-15

Purpose: The objective was to develop and investigate an automated scoring scheme of the American College of Radiology (ACR) mammographic accreditation phantom (RMI 156, Middleton, WI) images. Methods: The developed method consisted of background subtraction, determination of region of interest, classification of fiber and mass objects by Mahalanobis distance, detection of specks by template matching, and rule-based scoring. Fifty-one phantom images were collected from 51 facilities for this study (one facility provided one image). A medical physicist and two radiologic technologists also scored the images. The human and computerized scores were compared. Results: In terms of meeting the ACR's criteria,more » the accuracies of the developed method for computerized evaluation of fiber, mass, and speck were 90%, 80%, and 98%, respectively. Contingency table analysis revealed significant association between observer and computer scores for microcalcifications (p<5%) but not for masses and fibers. Conclusions: The developed method may achieve a stable assessment of visibility for test objects in mammographic accreditation phantom image in whether the phantom image meets the ACR's criteria in the evaluation test, although there is room left for improvement in the approach for fiber and mass objects.« less

Soccer Matches as Experiments - How Often Does the 'Best' Team Win?

NASA Technical Reports Server (NTRS)

Skinner, Gerald K.; Freeman, G. H.

2009-01-01

Models in which the number of goals scored by a team in a soccer match follow a Poisson distribution or a closely related one, have been widely discussed. We here consider a soccer match as an experiment to assess which of two teams is superior and examine the probability that the outcome of the experiment (match) truly represents the relative abilities of the two teams. Given a final score it is possible by using a Bayesian approach to quantify the probability that it was or was not the case that the best team won. For typical scores, the probability of a misleading result is significant. Modifying the rules of the game to increase thc typical number of goals scored would improve the situation, but a level of confidence that would normally be regarded as satisfactory could not be obtained unless the character of the game were radically changed.

Are Soccer Matches Badly Designed Experiments?

NASA Technical Reports Server (NTRS)

Skinner, G. K.; Freeman, G. H.

2008-01-01

Models in which the number of goals scored by a team in a soccer match follow a Poisson distribution, or a closely related one. have been widely discussed. We here consider a soccer match as an experiment to assess which of two teams is superior and examine the probability that the outcome of the experiment (match) truly represents the relative abilities of the two teams. Given a final score it is possible by using a Bayesian approach to quantify the probability that it was or was not the case that 'the best team won'. For typical scores, the probability of a misleading result is significant. Modifying the rules of the game to increase the typical number of goals scored would improve the situation, but a level of confidence that would normally be regarded as satisfactory could not be obtained unless the character of the game were radically changed.

Technical and Tactical Aspects that Differentiate Winning and Losing Performances in Elite Male Karate Fighters.

PubMed

Vidranski, Tihomir; Sertić, Hrvoje; Jukić, Josefina

2015-07-01

The purpose of this research was to identify the fighters' technical and tactical activity indicators in order to determine indicator significance regarding situational efficiency and designation between winning and losing performances in a karate match. We scientifically observed a sample of 274 male contesters of 137 karate matches during the 2008 World Karate Championship in Tokyo. Each individual competitor was observed in maximum of three matches. The matches were recorded using a DVD camera in order to collect data for further analysis, and the sample was further described using 48 technical and tactical indicators of situational efficiency and match outcome variables. The obtained results indicate that a karate match is composed of 91% of non-scoring techniques and 9% of scoring techniques in the total technique frequency. On this basis a significant difference in the situational efficiency between the match winners and the losing contesters has been discovered. Those two groups of fighters exhibit a statistically significant difference (p<0.05) in 11 out of 21 observed variables of situational efficiency in the table of derived situational indicators. A prevalence of non-scoring techniques suggests that energy demand and technical and tactical requirements of a karate match are in the largest extent defined by non-scoring techniques. Therefore, it would be a grave mistake to disregard non-scoring karate techniques in any future situational efficiency studies. It has been discovered that the winners differ from the defeated contesters by a higher level of situational efficiency in their executed techniques, which incorporate versatility, biomechanical and structural complexity, topological diversity and a specific tactical concept of technique use in the attack phase.

The Impact of Regression to the Mean on Economic Evaluation in Quasi-Experimental Pre-Post Studies: The Example of Total Knee Replacement Using Data from the Osteoarthritis Initiative.

PubMed

Schilling, Chris; Petrie, Dennis; Dowsey, Michelle M; Choong, Peter F; Clarke, Philip

2017-12-01

Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression to the mean (RTM). Ignoring RTM could bias the economic evaluation. We investigated this issue using the contemporary example of total knee replacement (TKR), a common treatment for end-stage osteoarthritis of the knee. Data (n = 4796) were obtained from the Osteoarthritis Initiative database, a longitudinal observational study of osteoarthritis. TKR patients (n = 184) were matched to non-TKR patients, using propensity score matching on the predicted hazard of TKR and exact matching on osteoarthritis severity and health-related quality of life (HrQoL). The economic evaluation using the matched control group was compared to the standard method of using the pre-surgery score as the control. Matched controls were identified for 56% of the primary TKRs. The matched control HrQoL trajectory showed evidence of RTM accounting for a third of the estimated QALY gains from surgery using the pre-surgery HrQoL as the control. Incorporating RTM into the economic evaluation significantly reduced the estimated cost effectiveness of TKR and increased the uncertainty. A generalized ICER bias correction factor was derived to account for RTM in cost-effectiveness analysis. RTM should be considered in economic evaluations based on quasi-experimental pre-post studies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Skeletal status and body composition in young women with functional hypothalamic amenorrhea.

PubMed

Podfigurna-Stopa, Agnieszka; Pludowski, Pawel; Jaworski, Maciej; Lorenc, Roman; Genazzani, Andrea R; Meczekalski, Blazej

2012-04-01

Functional hypothalamic amenorrhea (FHA) related to hypoestrogenism and hormonal status may influence skeletal homeostasis and body composition. The study aimed to evaluate hormones concentrations, body composition and bone strength in FHA cases. Total body scans using DXA method (DPX-L, GE Lunar) were performed in a group of 27 women aged 21.8 years ± 3.9 with FHA related to weight loss. References of healthy control subjects were used to calculate Z-scores (age and gender matched), SD-scores (height and gender matched), and SDs-scores (weight and gender matched). Whole skeleton bone mineral content (TBBMC, g) and density (TBBMD, g/cm(2)), lumbar spine (L2-L4) bone mineral density (SBMD; g/cm(2)), lean body mass (LBM, g) and fat mass (FM, g) were investigated. Relative bone strength index was calculated as the TBBMC/LBM ratio. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, testosterone, and prolactin (PRL) concentrations were assayed to characterize hormonal profile of FHA cases. Hormonal evaluation in patients with FHA revealed significantly decreased serum concentrations of gonadotropins and estradiol. Serum LH concentrations were 1.47 ± 0.89 mIU/ml, FSH 4.44 ± 1.94 mIU/ml. Estradiol concentrations in serum were 27.08 ± 13.10 pg/ml. As evidenced by Z-scores, FHA cases had decreased SBMD, TBBMD and TBBMC Z-scores of -1.23 ± 0.90 (p < 0.0001), -0.72 ± 0.86 (p < 0.001), and -0.90 ± 1.40 (p < 0.01), respectively. Reduced FM, LBM and FM/LBM ratio Z-scores of -1.80 ± 2.28 (p < 0.001), -0.59 ± 1.49 (p < 0.05) and -0.74 ± 1.55 (p < 0.05), but not TBBMC/LBM Z-score of -0.54 ± 2.14 (ns) were noted in FHA cases compared with healthy control cases. TBBMC, TBBMD, TBBMC/LBM when BH- or BW-matched were normal as evidenced by SD-scores and SDs-scores. SBMD remained reduced when BH-matched (SD-score = -0.40 ± 0.86; p < 0.05) whereas FM and FM/LBM were lower than expected in healthy, both compared to BH- and BW-dependent references. The length of amenorrhea in months negatively correlated with SBMD Z-score (R = -0.39, p < 0.05), and SD-scores for SBMD (R = -0.48), TBBMD (R = -0.43), TBBMC (R = -0.46) (all p < 0.05) and positively with SDs-scores for FM (R = 0.44, p < 0.05). Patients with FHA were characterized by lower concentrations of serum FSH, LH and estradiol concentrations. Moreover, FHA cases had decreased FM and an imbalanced relationship between BW, FM, and LBM. Despite reduced BMD and BMC, bone strength was not significantly affected by FHA.

Walking tree heuristics for biological string alignment, gene location, and phylogenies

NASA Astrophysics Data System (ADS)

Cull, P.; Holloway, J. L.; Cavener, J. D.

1999-03-01

Basic biological information is stored in strings of nucleic acids (DNA, RNA) or amino acids (proteins). Teasing out the meaning of these strings is a central problem of modern biology. Matching and aligning strings brings out their shared characteristics. Although string matching is well-understood in the edit-distance model, biological strings with transpositions and inversions violate this model's assumptions. We propose a family of heuristics called walking trees to align biologically reasonable strings. Both edit-distance and walking tree methods can locate specific genes within a large string when the genes' sequences are given. When we attempt to match whole strings, the walking tree matches most genes, while the edit-distance method fails. We also give examples in which the walking tree matches substrings even if they have been moved or inverted. The edit-distance method was not designed to handle these problems. We include an example in which the walking tree "discovered" a gene. Calculating scores for whole genome matches gives a method for approximating evolutionary distance. We show two evolutionary trees for the picornaviruses which were computed by the walking tree heuristic. Both of these trees show great similarity to previously constructed trees. The point of this demonstration is that WHOLE genomes can be matched and distances calculated. The first tree was created on a Sequent parallel computer and demonstrates that the walking tree heuristic can be efficiently parallelized. The second tree was created using a network of work stations and demonstrates that there is suffient parallelism in the phylogenetic tree calculation that the sequential walking tree can be used effectively on a network.

Chest compression quality management and return of spontaneous circulation: a matched-pair registry study.

PubMed

Lukas, Roman-Patrik; Gräsner, Jan Thorsten; Seewald, Stephan; Lefering, Rolf; Weber, Thomas Peter; Van Aken, Hugo; Fischer, Matthias; Bohn, Andreas

2012-10-01

Investigating the effects of any intervention during cardiac arrest remains difficult. The ROSC after cardiac arrest score was introduced to facilitate comparison of rates of return of spontaneous circulation (ROSC) between different ambulance services. To study the influence of chest compression quality management (including training, real-time feedback devices, and debriefing) in comparison with conventional cardiopulmonary resuscitation (CPR), a matched-pair analysis was conducted using data from the German Resuscitation Registry, with the calculated ROSC after cardiac arrest score as the baseline. Matching for independent ROSC after cardiac arrest score variables yielded 319 matched cases from the study period (January 2007-March 2011). The score predicted a 45% ROSC rate for the matched pairs. The observed ROSC increased significantly with chest compression quality management, to 52% (P=0.013; 95% CI, 46-57%). No significant differences were seen in the conventional CPR group (47%; 95% CI, 42-53%). The difference between the observed ROSC rates was not statistically significant. Chest compression quality management leads to significantly higher ROSC rates than those predicted by the prognostic score (ROSC after cardiac arrest score). Matched-pair analysis shows that with conventional CPR, the observed ROSC rate was not significantly different from the predicted rate. Analysis shows a trend toward a higher ROSC rate for chest compression quality management in comparison with conventional CPR. It is unclear whether a single aspect of chest compression quality management or the combination of training, real-time feedback, and debriefing contributed to this result. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Reliability of visual acuity measurements taken with a notebook and a tablet computer in participants who were illiterate to Roman characters.

PubMed

Ruamviboonsuk, Paisan; Sudsakorn, Napitchareeya; Somkijrungroj, Thanapong; Engkagul, Chayanee; Tiensuwan, Montip

2012-03-01

Electronic measurement of visual acuity (VA) has been proposed and adopted as a method of determining VA scores in clinical research. Characters (optotypes) are displayed on a monitor screen and the examinee selects a match and inputs his choice to another electronic device. Unfortunately, the optotypes, called Sloan letters, in the standard protocol are 10 Roman characters. This limits their practicabilityfor measuring VA of patients who are illiterate to these characters. The authors introduced a method of displaying the Sloan letters one by one on a notebook and all 10 Sloan letters on a tablet computer screen. The former is for testing the patients whereas the latter is for them to input their responses by tapping on a letter that matches the one on the notebook screen. To assess test-retest reliability of VA scores determined with this method. Participants without ocular abnormality were recruited to have their right eyes measured with the same VA measurement method twice, one week apart. Those who were illiterate to Roman characters were enrolled for the aforementioned method for measuring their VA (Tablet group). A 15-inch display notebook computer and a 9-inch display tablet computer (iPad) communicated via a local wireless data network provided by a Wi-Fi router. Those who understood Roman characters were enrolled to have measurements with a 17-inch desktop computer and an infrared wireless keyboard (Keyboard group). Both methods used the same protocols and software for VA measurements. Reliability of VA scores obtained from each group was assessed by the confidence interval (CI) of the difference of the scores from the test and retest. The t test was used to analyze differences in mean VA scores between the test and retest in each group with p < 0.05 determined as statistically significant. There were 49 and 50 participants in the Tablet and Keyboard group respectively. The 95% CI of the difference between the scores from the test and retest in each group was 2 letters. Approximately 95% of participants in each group had an absolute difference of the scores between the test and retest of 7 letters. The mean of VA scores from the first test was significantly different from that of the second test in the Keyboard group (one-letter difference, p = 0.049); there was no significant difference between these scores in the Tablet group (0.1-letter difference, p = 0.86). Tablet computers may be used to assist patients who are illiterate to Roman characters in having their VA measured with the standard electronic protocol. This preliminary study suggested that the proposed method should be useful for reliable measuring VA outcome in multicenter international clinical trials without encountering a language barrier

Evaluating Open-Source Full-Text Search Engines for Matching ICD-10 Codes.

PubMed

Jurcău, Daniel-Alexandru; Stoicu-Tivadar, Vasile

2016-01-01

This research presents the results of evaluating multiple free, open-source engines on matching ICD-10 diagnostic codes via full-text searches. The study investigates what it takes to get an accurate match when searching for a specific diagnostic code. For each code the evaluation starts by extracting the words that make up its text and continues with building full-text search queries from the combinations of these words. The queries are then run against all the ICD-10 codes until a match indicates the code in question as a match with the highest relative score. This method identifies the minimum number of words that must be provided in order for the search engines choose the desired entry. The engines analyzed include a popular Java-based full-text search engine, a lightweight engine written in JavaScript which can even execute on the user's browser, and two popular open-source relational database management systems.

Iris recognition using possibilistic fuzzy matching on local features.

PubMed

Tsai, Chung-Chih; Lin, Heng-Yi; Taur, Jinshiuh; Tao, Chin-Wang

2012-02-01

In this paper, we propose a novel possibilistic fuzzy matching strategy with invariant properties, which can provide a robust and effective matching scheme for two sets of iris feature points. In addition, the nonlinear normalization model is adopted to provide more accurate position before matching. Moreover, an effective iris segmentation method is proposed to refine the detected inner and outer boundaries to smooth curves. For feature extraction, the Gabor filters are adopted to detect the local feature points from the segmented iris image in the Cartesian coordinate system and to generate a rotation-invariant descriptor for each detected point. After that, the proposed matching algorithm is used to compute a similarity score for two sets of feature points from a pair of iris images. The experimental results show that the performance of our system is better than those of the systems based on the local features and is comparable to those of the typical systems.

Decomposing University Grades: A Longitudinal Study of Students and Their Instructors

ERIC Educational Resources Information Center

Beenstock, Michael; Feldman, Dan

2018-01-01

First-degree course grades for a cohort of social science students are matched to their instructors, and are statistically decomposed into departmental, course, instructor, and student components. Student ability is measured alternatively by university acceptance scores, or by fixed effects estimated using panel data methods. After controlling for…

Assessing Readiness for Online Education--Research Models for Identifying Students at Risk

ERIC Educational Resources Information Center

Wladis, Claire; Conway, Katherine M.; Hachey, Alyse C.

2016-01-01

This study explored the interaction between student characteristics and the online environment in predicting course performance and subsequent college persistence among students in a large urban U.S. university system. Multilevel modeling, propensity score matching, and the KHB decomposition method were used. The most consistent pattern observed…

Psychoeducational Characteristics of Children with Hypohidrotic Ectodermal Dysplasia

PubMed Central

Maxim, Rolanda A.; Zinner, Samuel H.; Matsuo, Hisako; Prosser, Theresa M.; Fete, Mary; Leet, Terry L.; Fete, Timothy J.

2012-01-01

Objective. Hypohidrotic ectodermal dysplasia (HED) is an X-linked hereditary disorder characterized by hypohidrosis, hypotrichosis, and anomalous dentition. Estimates of up to 50% of affected children having intellectual disability are controversial. Method. In a cross-sectional study, 45 youth with HED (77% males, mean age 9.75 years) and 59 matched unaffected controls (70% males, mean age 9.79 years) were administered the Kaufman Brief Intelligence Test and the Kaufman Test of Educational Achievement, and their parents completed standardized neurodevelopmental and behavioral measures, educational, and health-related information regarding their child, as well as standardized and nonstandardized data regarding socioeconomic information for their family. Results. There were no statistically significant differences between the two groups in intelligence quotient composite and educational achievement scores, suggesting absence of learning disability in either group. No gender differences within or between groups were found on any performance measures. Among affected youth, parental education level correlated positively with (1) cognitive vocabulary scores and cognitive composite scores; (2) educational achievement for mathematics, reading, and composite scores. Conclusion. Youth affected with HED and unaffected matched peers have similar profiles on standardized measures of cognition, educational achievement, and adaptive functioning although children with HED may be at increased risk for ADHD. PMID:22536143

Does the Consecutive Interpreting Approach enhance medical English communication skills of Japanese-speaking students?

PubMed Central

Lefor, Alan K.

2018-01-01

Objectives To determine if the Consecutive Interpreting Approach enhances medical English communication skills of students in a Japanese medical university and to assess this method based on performance and student evaluations.   Methods  This is a three-phase study using a mixed-methods design, which starts with four language reproduction activities for 30 medical and 95 nursing students, followed by a quantitative analysis of perfect-match reproduction rates to assess changes over the duration of the study and qualitative error analysis of participants' language reproduction. The final stage included a scored course evaluation and free-form comments to evaluate this approach and to identify effective educational strategies to enhance medical English communication skills. Results Mean perfect-match reproduction rates of all participants over four reproduction activities differed statistically significantly (repeated measures ANOVA, p<0.0005). The overall perfect-match reproduction rates improved from 75.3 % to 90.1 % for nursing and 89.5 % to 91.6% for medical students. The final achievement levels of nursing and medical students were equivalent (test of equivalence, p<0.05). Details of lexical- and syntactic-level errors were identified. The course evaluation scores were 3.74 (n=30, SD = 0.59) and 3.77 (n=90, SD=0.54) for medical and nursing students respectively. Conclusions Participants’ medical English communication skills are enhanced using this approach. Participants expressed positive feedback regarding this instruction method. This approach may be effective to enhance the language skills of non-native English-speaking students seeking to practice medicine in English speaking countries. PMID:29677693

Method and system for detecting polygon boundaries of structures in images as particle tracks through fields of corners and pixel gradients

DOEpatents

Paglieroni, David W [Pleasanton, CA; Manay, Siddharth [Livermore, CA

2011-12-20

A stochastic method and system for detecting polygon structures in images, by detecting a set of best matching corners of predetermined acuteness .alpha. of a polygon model from a set of similarity scores based on GDM features of corners, and tracking polygon boundaries as particle tracks using a sequential Monte Carlo approach. The tracking involves initializing polygon boundary tracking by selecting pairs of corners from the set of best matching corners to define a first side of a corresponding polygon boundary; tracking all intermediate sides of the polygon boundaries using a particle filter, and terminating polygon boundary tracking by determining the last side of the tracked polygon boundaries to close the polygon boundaries. The particle tracks are then blended to determine polygon matches, which may be made available, such as to a user, for ranking and inspection.

Trajectory Segmentation Map-Matching Approach for Large-Scale, High-Resolution GPS Data

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

Zhu, Lei; Holden, Jacob R.; Gonder, Jeffrey D.

With the development of smartphones and portable GPS devices, large-scale, high-resolution GPS data can be collected. Map matching is a critical step in studying vehicle driving activity and recognizing network traffic conditions from the data. A new trajectory segmentation map-matching algorithm is proposed to deal accurately and efficiently with large-scale, high-resolution GPS trajectory data. The new algorithm separated the GPS trajectory into segments. It found the shortest path for each segment in a scientific manner and ultimately generated a best-matched path for the entire trajectory. The similarity of a trajectory segment and its matched path is described by a similaritymore » score system based on the longest common subsequence. The numerical experiment indicated that the proposed map-matching algorithm was very promising in relation to accuracy and computational efficiency. Large-scale data set applications verified that the proposed method is robust and capable of dealing with real-world, large-scale GPS data in a computationally efficient and accurate manner.« less

Trajectory Segmentation Map-Matching Approach for Large-Scale, High-Resolution GPS Data

DOE PAGES

Zhu, Lei; Holden, Jacob R.; Gonder, Jeffrey D.

2017-01-01

With the development of smartphones and portable GPS devices, large-scale, high-resolution GPS data can be collected. Map matching is a critical step in studying vehicle driving activity and recognizing network traffic conditions from the data. A new trajectory segmentation map-matching algorithm is proposed to deal accurately and efficiently with large-scale, high-resolution GPS trajectory data. The new algorithm separated the GPS trajectory into segments. It found the shortest path for each segment in a scientific manner and ultimately generated a best-matched path for the entire trajectory. The similarity of a trajectory segment and its matched path is described by a similaritymore » score system based on the longest common subsequence. The numerical experiment indicated that the proposed map-matching algorithm was very promising in relation to accuracy and computational efficiency. Large-scale data set applications verified that the proposed method is robust and capable of dealing with real-world, large-scale GPS data in a computationally efficient and accurate manner.« less

Shade matching performance of normal and color vision-deficient dental professionals with standard daylight and tungsten illuminants.

PubMed

Gokce, Hasan Suat; Piskin, Bulent; Ceyhan, Dogan; Gokce, Sila Mermut; Arisan, Volkan

2010-03-01

The lighting conditions of the environment and visual deficiencies such as red-green color vision deficiency affect the clinical shade matching performance of dental professionals. The purpose of this study was to evaluate the shade matching performance of normal and color vision-deficient dental professionals with standard daylight and tungsten illuminants. Two sets of porcelain disc replicas of 16 shade guide tabs (VITA Lumin) were manufactured to exact L*a*b* values by using a colorimeter. Then these twin porcelain discs (13 mm x 2.4 mm) were mixed up and placed into a color-matching cabinet that standardized the lighting conditions for the observation tests. Normal and red-green color vision-deficient dental professionals were asked to match the 32 porcelain discs using standard artificial daylight D65 (high color temperature) and tungsten filament lamp light (T) (low color temperature) illuminants. The results were analyzed by repeated-measures ANOVA and paired and independent samples t tests for the differences between dental professionals and differences between the illuminants (alpha=.05). Regarding the sum of the correct shade match scores of all observations with both illuminants, the difference between normal vision and red-green color vision-deficient dental professional groups was not statistically significant (F=4.132; P=.054). However, the correct shade match scores of each group were significantly different for each illuminant (P<.005). The correct shade matching scores of normal color vision dental professionals were significantly higher with D65 illuminant (t=7.004; P<.001). Color matching scores of red-green color vision-deficient dental professionals (approximately 5.7 more pairs than with D65) were significantly higher with T illuminant (t=5.977; P<.001). CONCLUSIONS.: Within the limitations of this study, the shade matching performance of dental professionals was affected by color vision deficiency and the color temperature of the illuminant. The color vision-deficient group was notably unsuccessful with the D65 illuminant in shade matching. In contrast, there was a significant increase in the shade matching performance of the color vision-deficient group with T illuminant. The lower color temperature illuminant dramatically decreased the normal color vision groups' correct shade matching score. (c) 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

The network structure of human personality according to the NEO-PI-R: matching network community structure to factor structure.

PubMed

Goekoop, Rutger; Goekoop, Jaap G; Scholte, H Steven

2012-01-01

Human personality is described preferentially in terms of factors (dimensions) found using factor analysis. An alternative and highly related method is network analysis, which may have several advantages over factor analytic methods. To directly compare the ability of network community detection (NCD) and principal component factor analysis (PCA) to examine modularity in multidimensional datasets such as the neuroticism-extraversion-openness personality inventory revised (NEO-PI-R). 434 healthy subjects were tested on the NEO-PI-R. PCA was performed to extract factor structures (FS) of the current dataset using both item scores and facet scores. Correlational network graphs were constructed from univariate correlation matrices of interactions between both items and facets. These networks were pruned in a link-by-link fashion while calculating the network community structure (NCS) of each resulting network using the Wakita Tsurumi clustering algorithm. NCSs were matched against FS and networks of best matches were kept for further analysis. At facet level, NCS showed a best match (96.2%) with a 'confirmatory' 5-FS. At item level, NCS showed a best match (80%) with the standard 5-FS and involved a total of 6 network clusters. Lesser matches were found with 'confirmatory' 5-FS and 'exploratory' 6-FS of the current dataset. Network analysis did not identify facets as a separate level of organization in between items and clusters. A small-world network structure was found in both item- and facet level networks. We present the first optimized network graph of personality traits according to the NEO-PI-R: a 'Personality Web'. Such a web may represent the possible routes that subjects can take during personality development. NCD outperforms PCA by producing plausible modularity at item level in non-standard datasets, and can identify the key roles of individual items and clusters in the network.

Cross-modal face recognition using multi-matcher face scores

NASA Astrophysics Data System (ADS)

Zheng, Yufeng; Blasch, Erik

2015-05-01

The performance of face recognition can be improved using information fusion of multimodal images and/or multiple algorithms. When multimodal face images are available, cross-modal recognition is meaningful for security and surveillance applications. For example, a probe face is a thermal image (especially at nighttime), while only visible face images are available in the gallery database. Matching a thermal probe face onto the visible gallery faces requires crossmodal matching approaches. A few such studies were implemented in facial feature space with medium recognition performance. In this paper, we propose a cross-modal recognition approach, where multimodal faces are cross-matched in feature space and the recognition performance is enhanced with stereo fusion at image, feature and/or score level. In the proposed scenario, there are two cameras for stereo imaging, two face imagers (visible and thermal images) in each camera, and three recognition algorithms (circular Gaussian filter, face pattern byte, linear discriminant analysis). A score vector is formed with three cross-matched face scores from the aforementioned three algorithms. A classifier (e.g., k-nearest neighbor, support vector machine, binomial logical regression [BLR]) is trained then tested with the score vectors by using 10-fold cross validations. The proposed approach was validated with a multispectral stereo face dataset from 105 subjects. Our experiments show very promising results: ACR (accuracy rate) = 97.84%, FAR (false accept rate) = 0.84% when cross-matching the fused thermal faces onto the fused visible faces by using three face scores and the BLR classifier.

Eating behaviors in obese children with pseudohypoparathyroidism type 1a: a cross-sectional study

PubMed Central

2014-01-01

Background Children with pseudohypoparathyroidism type 1a (PHP-1a) develop early-onset obesity. These children have decreased resting energy expenditure but it is unknown if hyperphagia contributes to their obesity. Methods We conducted a survey assessment of patients 2 to 12 years old with PHP-1a and matched controls using the Hyperphagia Questionnaire (HQ) and Children’s Eating Behavior Questionnaire (CEBQ). Results of the PHP-1a group were also compared with an obese control group and normal weight sibling group. Results We enrolled 10 patients with PHP-1a and 9 matched controls. There was not a significant difference between the PHP-1a group and matched controls for total HQ score (p = 0.72), Behavior (p = 0.91), Drive (p = 0.48) or Severity (p = 0.73) subset scores. There was also no difference between the PHP-1a group and matched controls on the CEBQ. In a secondary analysis, the PHP-1a group was compared with obese controls (n = 30) and normal weight siblings (n = 6). Caregivers reported an increased interest in food before age 2 years in 6 of 10 PHP-1a patients (60%), 9 of 30 obese controls (30%) and none of the siblings (p = 0.04). The sibling group had a significantly lower Positive Eating Behavior score than the PHP-1a group (2.6 [2.4, 2.9] vs. 3.5 [3.1, 4.0], p < 0.01) and obese controls (2.6 [2.4, 2.9] vs. 3.4 [2.6, 3.8], p = 0.04), but there was not a significant difference between the PHP-1a and obese controls (p = 0.35). The sibling group had a lower Desire to Drink score than both the PHP-1a group (1.8 [1.6, 2.7] vs. 4.3 [3.3, 5.0], p < 0.01) and obese controls (1.8 [1.6, 2.7] vs. 3.3 [3.0, 4.0], p < 0.01) but there was not a significant difference between the PHP-1a and obese control Desire to Drink scores (p = 0.11). Conclusions Patients with PHP-1a demonstrate hyperphagic symptoms similar to matched obese controls. PMID:25337124

Effectiveness of Cetuximab in Combination with Concurrent Chemoradiotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: A 1:2 Propensity Score-matched Analysis.

PubMed

Wu, Li-Rong; Zhu, Huan-Feng; Xu, Jianhua; Jiang, Xue-Song; Yin, Li; Jiang, Ning; Zong, Dan; Wang, Fei-Jiang; Huang, Sheng-Fu; Bian, Xiu-Hua; Wu, Jian-Feng; Song, Dan; Guo, Wen-Jie; Liu, Ju-Ying; He, Xia

2018-01-01

Background : This study aimed to compare concurrent chemoradiotherapy (CCRT) plus cetuximab (C) with CCRT alone in locoregionally advanced nasopharyngeal carcinoma(NPC). Methods : A total of 682 locoregionally advanced NPC patients who had undergone chemoradiotherapy with or without cetuximab were included. Propensity score-matching method was used to match patients. Progression-free survival (PFS), overall survival (OS), locoregional relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared between the two treatment arms. Results : After matching, 225 patients were identified for the analysis. Compared to CCRT, CCRT plus C was associated with significantly improved 3-year PFS (83.7% vs 71.9%, P = 0.036), LRFS (98.6% vs 90.2%, P = 0.034) but not OS (91.4% vs 85.4%, P = 0.117). Among patients with T4 and/or N3 category, CCRT plus C significantly prolonged 3-year PFS (81.0% vs 61.4%, P = 0.022) and increased 3-year OS (88.0% vs 77.9%, P = 0.086). No significant differences were observed between CCRT plus C and CCRT alone groups with regard to 3-year PFS, OS, LRFS and DMFS rates in stage III patients. Acute oral and oropharyngeal mucositis during radiotherapy were more common in the CCRT plus C than that in CCRT, but late toxicities were comparable. Conclusions: This study reveals that patients with locoregionally advanced NPC could benefit from the addition of cetuximab to CCRT, and this therapeutic gain mainly originated from T4 and/or N3 subgroup although suffering more acute moderate to severe toxicities.

Maternal Employment and Child Development: A Fresh Look Using Newer Methods

ERIC Educational Resources Information Center

Hill, Jennifer L.; Waldfogel, Jane; Brooks-Gunn, Jeanne; Han, Wen-Jui

2005-01-01

The employment rate for mothers with young children has increased dramatically over the past 25 years. Estimating the effects of maternal employment on children's development is challenged by selection bias and the missing data endemic to most policy research. To address these issues, this study uses propensity score matching and multiple…

Quantifying individual performance in Cricket — A network analysis of batsmen and bowlers

NASA Astrophysics Data System (ADS)

Mukherjee, Satyam

2014-01-01

Quantifying individual performance in the game of Cricket is critical for team selection in International matches. The number of runs scored by batsmen and wickets taken by bowlers serves as a natural way of quantifying the performance of a cricketer. Traditionally the batsmen and bowlers are rated on their batting or bowling average respectively. However, in a game like Cricket it is always important the manner in which one scores the runs or claims a wicket. Scoring runs against a strong bowling line-up or delivering a brilliant performance against a team with a strong batting line-up deserves more credit. A player’s average is not able to capture this aspect of the game. In this paper we present a refined method to quantify the ‘quality’ of runs scored by a batsman or wickets taken by a bowler. We explore the application of Social Network Analysis (SNA) to rate the players in a team performance. We generate a directed and weighted network of batsmen-bowlers using the player-vs-player information available for Test cricket and ODI cricket. Additionally we generate a network of batsmen and bowlers based on the dismissal record of batsmen in the history of cricket-Test (1877-2011) and ODI (1971-2011). Our results show that M. Muralitharan is the most successful bowler in the history of Cricket. Our approach could potentially be applied in domestic matches to judge a player’s performance which in turn paves the way for a balanced team selection for International matches.

The effect of intrapartum antibiotics on early-onset neonatal sepsis in Dhaka, Bangladesh: a propensity score matched analysis

PubMed Central

2014-01-01

Background We estimate the effect of antibiotics given in the intrapartum period on early-onset neonatal sepsis in Dhaka, Bangladesh using propensity score techniques. Methods We followed 600 mother-newborn pairs as part of a cohort study at a maternity center in Dhaka. Some pregnant women received one dose of intravenous antibiotics during labor based on clinician discretion. Newborns were followed over the first seven days of life for early-onset neonatal sepsis defined by a modified version of the World Health Organization Young Infants Integrated Management of Childhood Illnesses criteria. Using propensity scores we matched women who received antibiotics with similar women who did not. A final logistic regression model predicting sepsis was run in the matched sample controlling for additional potential confounders. Results Of the 600 mother-newborn pairs, 48 mothers (8.0%) received antibiotics during the intrapartum period. Seventy-seven newborns (12.8%) were classified with early-onset neonatal sepsis. Antibiotics appeared to be protective (odds ratio 0.381, 95% confidence interval 0.115–1.258), however this was not statistically significant. The results were similar after adjusting for prematurity, wealth status, and maternal colonization status (odds ratio 0.361, 95% confidence interval 0.106–1.225). Conclusions Antibiotics administered during the intrapartum period may reduce the risk of early-onset neonatal sepsis in high neonatal mortality settings like Dhaka. PMID:24742087

The “Dry-Run” Analysis: A Method for Evaluating Risk Scores for Confounding Control

PubMed Central

Wyss, Richard; Hansen, Ben B.; Ellis, Alan R.; Gagne, Joshua J.; Desai, Rishi J.; Glynn, Robert J.; Stürmer, Til

2017-01-01

Abstract A propensity score (PS) model's ability to control confounding can be assessed by evaluating covariate balance across exposure groups after PS adjustment. The optimal strategy for evaluating a disease risk score (DRS) model's ability to control confounding is less clear. DRS models cannot be evaluated through balance checks within the full population, and they are usually assessed through prediction diagnostics and goodness-of-fit tests. A proposed alternative is the “dry-run” analysis, which divides the unexposed population into “pseudo-exposed” and “pseudo-unexposed” groups so that differences on observed covariates resemble differences between the actual exposed and unexposed populations. With no exposure effect separating the pseudo-exposed and pseudo-unexposed groups, a DRS model is evaluated by its ability to retrieve an unconfounded null estimate after adjustment in this pseudo-population. We used simulations and an empirical example to compare traditional DRS performance metrics with the dry-run validation. In simulations, the dry run often improved assessment of confounding control, compared with the C statistic and goodness-of-fit tests. In the empirical example, PS and DRS matching gave similar results and showed good performance in terms of covariate balance (PS matching) and controlling confounding in the dry-run analysis (DRS matching). The dry-run analysis may prove useful in evaluating confounding control through DRS models. PMID:28338910

Unmatched U.S. Allopathic Seniors in the 2015 Main Residency Match: A Study of Applicant Behavior, Interview Selection, and Match Outcome.

PubMed

Liang, Mei; Curtin, Laurie S; Signer, Mona M; Savoia, Maria C

2017-07-01

The application and interview behaviors of unmatched U.S. allopathic medical school senior students (U.S. seniors) participating in the 2015 National Resident Matching Program (NRMP) Main Residency Match were studied in conjunction with their United States Medical Licensing Examination (USMLE) Step 1 scores and ranking preferences to understand their effects on Match outcome. USMLE Step 1 score and preferred specialty information were reviewed for U.S. seniors who responded to the 2015 NRMP Applicant Survey. Unmatched U.S. seniors were categorized as "strong," "solid," "marginal," or "weak" based on the perceived competitiveness of their Step 1 scores compared with U.S. seniors who matched in the same preferred specialty. The numbers of applications sent, interviews obtained, and programs ranked also were examined by Match outcome. Strong unmatched U.S. seniors submitted significantly more applications to achieve and attend approximately the same number of interviews as strong matched U.S. seniors. Strong unmatched seniors ranked fewer programs than their matched counterparts. As a group, unmatched U.S. seniors were less likely than their matched counterparts to rank a mix of competitive and less competitive programs and more likely to rank programs based on their perceived likelihood of matching. A small number of unmatched U.S. seniors would have matched if they had ranked programs that ranked them. U.S. seniors' Match outcomes may be affected by applicant characteristics that negatively influence their selection for interviews, and their difficulties may be exacerbated by disadvantageous ranking behaviors.

How does the past of a soccer match influence its future? Concepts and statistical analysis.

PubMed

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified.

How Does the Past of a Soccer Match Influence Its Future? Concepts and Statistical Analysis

PubMed Central

Heuer, Andreas; Rubner, Oliver

2012-01-01

Scoring goals in a soccer match can be interpreted as a stochastic process. In the most simple description of a soccer match one assumes that scoring goals follows from independent rate processes of both teams. This would imply simple Poissonian and Markovian behavior. Deviations from this behavior would imply that the previous course of the match has an impact on the present match behavior. Here a general framework for the identification of deviations from this behavior is presented. For this endeavor it is essential to formulate an a priori estimate of the expected number of goals per team in a specific match. This can be done based on our previous work on the estimation of team strengths. Furthermore, the well-known general increase of the number of the goals in the course of a soccer match has to be removed by appropriate normalization. In general, three different types of deviations from a simple rate process can exist. First, the goal rate may depend on the exact time of the previous goals. Second, it may be influenced by the time passed since the previous goal and, third, it may reflect the present score. We show that the Poissonian scenario is fulfilled quite well for the German Bundesliga. However, a detailed analysis reveals significant deviations for the second and third aspect. Dramatic effects are observed if the away team leads by one or two goals in the final part of the match. This analysis allows one to identify generic features about soccer matches and to learn about the hidden complexities behind scoring goals. Among others the reason for the fact that the number of draws is larger than statistically expected can be identified. PMID:23226200

From scores to face templates: a model-based approach.

PubMed

Mohanty, Pranab; Sarkar, Sudeep; Kasturi, Rangachar

2007-12-01

Regeneration of templates from match scores has security and privacy implications related to any biometric authentication system. We propose a novel paradigm to reconstruct face templates from match scores using a linear approach. It proceeds by first modeling the behavior of the given face recognition algorithm by an affine transformation. The goal of the modeling is to approximate the distances computed by a face recognition algorithm between two faces by distances between points, representing these faces, in an affine space. Given this space, templates from an independent image set (break-in) are matched only once with the enrolled template of the targeted subject and match scores are recorded. These scores are then used to embed the targeted subject in the approximating affine (non-orthogonal) space. Given the coordinates of the targeted subject in the affine space, the original template of the targeted subject is reconstructed using the inverse of the affine transformation. We demonstrate our ideas using three, fundamentally different, face recognition algorithms: Principal Component Analysis (PCA) with Mahalanobis cosine distance measure, Bayesian intra-extrapersonal classifier (BIC), and a feature-based commercial algorithm. To demonstrate the independence of the break-in set with the gallery set, we select face templates from two different databases: Face Recognition Grand Challenge (FRGC) and Facial Recognition Technology (FERET) Database (FERET). With an operational point set at 1 percent False Acceptance Rate (FAR) and 99 percent True Acceptance Rate (TAR) for 1,196 enrollments (FERET gallery), we show that at most 600 attempts (score computations) are required to achieve a 73 percent chance of breaking in as a randomly chosen target subject for the commercial face recognition system. With similar operational set up, we achieve a 72 percent and 100 percent chance of breaking in for the Bayesian and PCA based face recognition systems, respectively. With three different levels of score quantization, we achieve 69 percent, 68 percent and 49 percent probability of break-in, indicating the robustness of our proposed scheme to score quantization. We also show that the proposed reconstruction scheme has 47 percent more probability of breaking in as a randomly chosen target subject for the commercial system as compared to a hill climbing approach with the same number of attempts. Given that the proposed template reconstruction method uses distinct face templates to reconstruct faces, this work exposes a more severe form of vulnerability than a hill climbing kind of attack where incrementally different versions of the same face are used. Also, the ability of the proposed approach to reconstruct actual face templates of the users increases privacy concerns in biometric systems.

Database extraction strategies for low-template evidence.

PubMed

Bleka, Øyvind; Dørum, Guro; Haned, Hinda; Gill, Peter

2014-03-01

Often in forensic cases, the profile of at least one of the contributors to a DNA evidence sample is unknown and a database search is needed to discover possible perpetrators. In this article we consider two types of search strategies to extract suspects from a database using methods based on probability arguments. The performance of the proposed match scores is demonstrated by carrying out a study of each match score relative to the level of allele drop-out in the crime sample, simulating low-template DNA. The efficiency was measured by random man simulation and we compared the performance using the SGM Plus kit and the ESX 17 kit for the Norwegian population, demonstrating that the latter has greatly enhanced power to discover perpetrators of crime in large national DNA databases. The code for the database extraction strategies will be prepared for release in the R-package forensim. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Rapid motif compliance scoring with match weight sets.

PubMed

Venezia, D; O'Hara, P J

1993-02-01

Most current implementations of motif matching in biological sequences have sacrificed the generality of weight matrix scoring for shorter runtimes. The program MOTIF incorporates a weight matrix and a rapid, backtracking tree-search algorithm to score motif compliance with greatly enhanced performance while placing no constraints on the motif. In addition, any positions within a motif can be marked as 'inviolate', thereby requiring an exact match. MOTIF allows a choice of regular expression formats and can use both motif and sequence libraries as either targets or queries. Nucleic acid sequences can optionally be translated by MOTIF in any frame(s) and used against peptide motifs.

Effect of Age on Glasgow Coma Scale in Patients with Moderate and Severe Traumatic Brain Injury: An Approach with Propensity Score-Matched Population.

PubMed

Rau, Cheng-Shyuan; Wu, Shao-Chun; Chen, Yi-Chun; Chien, Peng-Chen; Hsieh, Hsiao-Yun; Kuo, Pao-Jen; Hsieh, Ching-Hua

2017-11-13

Background: The most widely used methods of describing traumatic brain injury (TBI) are the Glasgow Coma Scale (GCS) and the Abbreviated Injury Scale (AIS). Recent evidence suggests that presenting GCS in older patients may be higher than that in younger patients for an equivalent anatomical severity of TBI. This study aimed to assess these observations with a propensity-score matching approach using the data from Trauma Registry System in a Level I trauma center. Methods: We included all adult patients (aged ≥20 years old) with moderate to severe TBI from 1 January 2009 to 31 December 2016. Patients were categorized into elderly (aged ≥65 years) and young adults (aged 20-64 years). The severity of TBI was defined by an AIS score in the head (AIS 3‒4 and 5 indicate moderate and severe TBI, respectively). We examined the differences in the GCS scores by age at each head AIS score. Unpaired Student's t - and Mann-Whitney U -tests were used to analyze normally and non-normally distributed continuous data, respectively. Categorical data were compared using either the Pearson chi-square or two-sided Fisher's exact tests. Matched patient populations were allocated in a 1:1 ratio according to the propensity scores calculated using NCSS software with the following covariates: sex, pre-existing chronic obstructive pulmonary disease, systolic blood pressure, hemoglobin, sodium, glucose, and alcohol level. Logistic regression was used to evaluate the effects of age on the GCS score in each head AIS stratum. Results: The study population included 2081 adult patients with moderate to severe TBI. These patients were categorized into elderly ( n = 847) and young adults ( n = 1234): each was exclusively further divided into three groups of patients with head AIS of 3, 4, or 5. In the 162 well-balanced pairs of TBI patients with head AIS of 3, the elderly demonstrated a significantly higher GCS score than the young adults (14.1 ± 2.2 vs. 13.1 ± 3.3, respectively; p = 0.002). In the 362 well-balanced pairs of TBI patients with head AIS of 4, the elderly showed a significantly higher GCS score than the young adults (13.1 ± 3.3 vs. 12.2 ± 3.8, respectively; p = 0.002). In the 89 well-balance pairs of TBI patients with head AIS of 5, no significant differences were observed for the GCS scores. Conclusions: This study demonstrated that elderly patients with moderate TBI present higher GCS score than younger patients. This study underscores the importance of determining of TBI severity in this group of elderly patients based on the GCS score alone. A lower threshold of GCS cutoff should be adopted in the management of the elderly patients with TBI.

Proton pump inhibitor use and recurrent Clostridium difficile-associated disease: a case-control analysis matched by propensity score.

PubMed

Kim, Yong Gil; Graham, David Y; Jang, Byung Ik

2012-01-01

Clostridium difficile has been increasingly diagnosed in hospitalized patients. An association between proton pump inhibitors (PPIs) use and Clostridium difficile-associated disease (CDAD) and between recurrent CDAD has been suggested. The aim of this study is to investigate whether PPI use is associated with the development of recurrent CDAD. This was a retrospective case-control study of patients with CDAD at Yeungnam University Medical Center, seen from January 2004 to December 2008. C. difficile infection was diagnosed by the presence of C. difficile toxin in the stool. Those with recurrent disease were matched with nonrecurrent controls using multivariate matched sampling methods that incorporated the propensity score. Recurrent CDAD developed in 28 (14.1%) of the 198 patients with diarrhea and positive C. difficile stool toxin assays. Multivariate analysis of the total population of recurrent versus nonrecurrent CDAD revealed that additional use of non-C. difficile antimicrobial therapy (concomitant with the treatment or after or both), poor response to therapy with metronidazole or vancomycin, and recent gastrointestinal surgery were risk factors for recurrent CDAD. We were able to match 21 recurrent CDAD subjects with 21 without recurrent CDAD. Among the matched patients only PPI use was associated with recurrent CDAD (ie, 47.6% vs. 4.8%, P=0.004 for recurrent vs. nonrecurrent CDAD, respectively). Among the matched patient groups, only PPI therapy was associated with recurrent CDAD. Prospective studies are needed to clarify whether avoidance of PPIs or specific cotherapies will reduce the incidence of recurrent C. difficile-associated diarrhea.

Estimating error rates for firearm evidence identifications in forensic science

PubMed Central

Song, John; Vorburger, Theodore V.; Chu, Wei; Yen, James; Soons, Johannes A.; Ott, Daniel B.; Zhang, Nien Fan

2018-01-01

Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed congruent matching cells (CMC) method for image comparisons, its application to firearm evidence identification, and its usage and initial tests for error rate estimation. The CMC method divides compared topography images into correlation cells. Four identification parameters are defined for quantifying both the topography similarity of the correlated cell pairs and the pattern congruency of the registered cell locations. A declared match requires a significant number of CMCs, i.e., cell pairs that meet all similarity and congruency requirements. Initial testing on breech face impressions of a set of 40 cartridge cases fired with consecutively manufactured pistol slides showed wide separation between the distributions of CMC numbers observed for known matching and known non-matching image pairs. Another test on 95 cartridge cases from a different set of slides manufactured by the same process also yielded widely separated distributions. The test results were used to develop two statistical models for the probability mass function of CMC correlation scores. The models were applied to develop a framework for estimating cumulative false positive and false negative error rates and individual error rates of declared matches and non-matches for this population of breech face impressions. The prospect for applying the models to large populations and realistic case work is also discussed. The CMC method can provide a statistical foundation for estimating error rates in firearm evidence identifications, thus emulating methods used for forensic identification of DNA evidence. PMID:29331680

Estimating error rates for firearm evidence identifications in forensic science.

PubMed

Song, John; Vorburger, Theodore V; Chu, Wei; Yen, James; Soons, Johannes A; Ott, Daniel B; Zhang, Nien Fan

2018-03-01

Estimating error rates for firearm evidence identification is a fundamental challenge in forensic science. This paper describes the recently developed congruent matching cells (CMC) method for image comparisons, its application to firearm evidence identification, and its usage and initial tests for error rate estimation. The CMC method divides compared topography images into correlation cells. Four identification parameters are defined for quantifying both the topography similarity of the correlated cell pairs and the pattern congruency of the registered cell locations. A declared match requires a significant number of CMCs, i.e., cell pairs that meet all similarity and congruency requirements. Initial testing on breech face impressions of a set of 40 cartridge cases fired with consecutively manufactured pistol slides showed wide separation between the distributions of CMC numbers observed for known matching and known non-matching image pairs. Another test on 95 cartridge cases from a different set of slides manufactured by the same process also yielded widely separated distributions. The test results were used to develop two statistical models for the probability mass function of CMC correlation scores. The models were applied to develop a framework for estimating cumulative false positive and false negative error rates and individual error rates of declared matches and non-matches for this population of breech face impressions. The prospect for applying the models to large populations and realistic case work is also discussed. The CMC method can provide a statistical foundation for estimating error rates in firearm evidence identifications, thus emulating methods used for forensic identification of DNA evidence. Published by Elsevier B.V.

Incidence of opioid-managed pelvic pain after hysteroscopic sterilization versus laparoscopic sterilization, U.S. 2005-2012

PubMed Central

Conover, Mitchell M.; Howell, Jennifer O.; Wu, Jennifer M.; Kinlaw, Alan C.; Dasgupta, Nabarun; Funk, Michele Jonsson

2015-01-01

Objective Compare incidence of opioid-managed pelvic pain within 12-months after hysteroscopic and laparoscopic sterilization. Methods Using administrative claims, we identified women age 18-49 without recent history of childbirth who underwent hysteroscopic or laparoscopic sterilization between 2005-2012. We defined the outcome as ≥2 diagnoses for pelvic pain and ≥2 prescription fills for opioids. We calculated adjusted hazard ratios (HR) using Cox models and propensity score methods (matching and inverse-probability-of-treatment-weighting [IPTW]). Results We identified 71,875 eligible women (hysteroscopic n=26,927 [37.5%], laparoscopic n=44,948 [62.5%]). Of those, 236 (0.88%) hysteroscopic patients and 420 (0.93%) laparoscopic patients experienced the outcome (crude HR=0.97, [95%CI: 0.83, 1.14]). Adjusted analyses also yielded near-null results (matched HR=1.08 [95%CI: 0.90, 1.31]; IPTW HR=0.97 [95%CI: 0.80, 1.18]). While most sensitivity analyses generated results close to the null, hazard ratios estimated using propensity score matching ranged from 0.65 to 1.53. Conclusions Among women without recent history of childbirth, we did not find compelling evidence of a clinically meaningful increase in the incidence of pelvic pain requiring opioids during the year after hysteroscopic sterilization. However, effects observed in sensitivity analyses may merit further investigation. PMID:25832014

Applicant Characteristics Associated with Successful Matching into Otolaryngology

PubMed Central

Hauser, Leah J.; Gebhard, Grant M.; Blumhagen, Rachel; Carlson, Nichole E.; Cabrera-Muffly, Cristina

2016-01-01

Objective To identify resident applicant characteristics that increase the odds of matching to Otolaryngology residency. Study Design Cross-sectional analysis. Methods Residency applications to our institution from 2009 through 2013 were reviewed. The available data represented 81.1% of applicants to Otolaryngology programs nationwide. Online public records were searched to determine whether an applicant matched to an Otolaryngology residency position. Factors that were significantly associated with the odds of matching were determined using logistic regression. Results A total of 1,479 unique applications were analyzed. On univariate analysis, 27 demographic, academic, personal, medical school, prior training, and application-specific factors were associated with the odds of matching into Otolaryngology. On multivariate analysis, indicators of academic achievement, including AOA status, whether applicant received awards, and publications were significantly associated with the odds of matching (OR 2.03, 1.39, 1.66, respectively). The odds of matching increased with increasing Step 1 scores (p<0.001). Attending a medical school ranked by the US News & World Report and being a US citizen born in the US significantly increased odds of matching (OR 1.55 and 2.04, respectively), while being a non-US Senior significantly decreased the odds of matching (OR 0.33). Conclusion Multiple factors are associated with successfully matching into an Otolaryngology residency. While this information allows medical students to determine the strength of their application, these criteria have not been correlated with resident success. We urge selection committees to begin identifying applicant selection methods that reflect the values we want to cultivate in our future colleagues. PMID:27767217

Impact of prestroke selective serotonin reuptake inhibitor treatment on stroke severity and mortality.

PubMed

Mortensen, Janne Kaergaard; Larsson, Heidi; Johnsen, Søren Paaske; Andersen, Grethe

2014-07-01

Selective serotonin reuptake inhibitors (SSRIs) have been associated with an increased risk of bleeding but also a possible neuroprotective effect in stroke. We aimed to examine the implications of prestroke SSRI use in hemorrhagic and ischemic stroke. We conducted a registry-based propensity score-matched follow-up study among first-ever patients with hemorrhage and ischemic stroke in Denmark (2003-2012). Multiple conditional logistic regression was used to compute adjusted odds ratios of severe stroke and death within 30 days. Among 1252 hemorrhagic strokes (626 prestroke SSRI users and 626 propensity score-matched nonusers), prestroke SSRI use was associated with an increased risk of the strokes being severe (adjusted propensity score-matched odds ratios, 1.41; confidence interval, 1.08-1.84) and an increased risk of death within 30 days (adjusted propensity score-matched odds ratios, 1.60; confidence interval, 1.17-2.18). Among 8956 patients with ischemic stroke (4478 prestroke SSRI users and 4478 propensity score-matched nonusers), prestroke SSRI use was not associated with the risk of severe stroke or death within 30 days. Prestroke SSRI use is associated with increased stroke severity and mortality in patients with hemorrhagic stroke. Although prestroke depression in itself may increase stroke severity and mortality, this was not found in SSRI users with ischemic stroke. © 2014 American Heart Association, Inc.

Tribocorrosion: Ceramic and Oxidized Zirconium vs Cobalt-Chromium Heads in Total Hip Arthroplasty.

PubMed

Tan, Sok Chuen; Lau, Adrian C K; Del Balso, Christopher; Howard, James L; Lanting, Brent A; Teeter, Matthew G

2016-09-01

This matched-cohort study aims to compare tribocorrosion between matched ceramic and cobalt-chromium femoral head trunnions and between matched Oxinium and cobalt-chromium femoral head trunnions. Secondary objectives were to investigate whether taper design, depth of trunnion, implantation time, age, body mass index, and gender have an effect on fretting and corrosion. All hip prostheses retrieved between 1999 and 2015 at one center were reviewed, giving a total of 52 ceramic heads. These were matched to a cobalt-chromium cohort according to taper design, head size, neck length, and implantation time. The trunnions were examined by 2 observers using a 4-point scoring technique and scored in 3 zones: apex, middle, and base. The observers were blinded to clinical and manufacturing data where possible. A separate matched-cohort analysis was performed between 8 Oxinium heads and 8 cobalt-chromium heads, which were similarly scored. Ceramic head trunnions demonstrated a lower median fretting and corrosion score at the base zone (P < .001), middle zone (P < .001), and in the combined score (P < .001). Taper design had a significant effect on fretting and corrosion in the apex zone (P = .04) of the ceramic group, as well as the cobalt-chromium group (P = .03). Between Oxinium heads and cobalt-chromium heads, there was no significant difference in the fretting and corrosion score across all 3 zones (base: P = .22; middle: P = .92; and apex: P = .71) and for the combined score (P = .67). This study shows that ceramic head confers an advantage in trunnion fretting and corrosion. Taper design and implantation time were also significant factors for fretting and corrosion. Copyright © 2016 Elsevier Inc. All rights reserved.

Risk of poor neonatal outcome at term after medically assisted reproduction: a propensity score-matched study.

PubMed

Ensing, Sabine; Abu-Hanna, Ameen; Roseboom, Tessa J; Repping, Sjoerd; van der Veen, Fulco; Mol, Ben Willem J; Ravelli, Anita C J

2015-08-01

To study risk of birth asphyxia and related morbidity among term singletons born after medically assisted reproduction (MAR). Population cohort study. Not applicable. A total of 1,953,932 term singleton pregnancies selected from a national registry for 1999-2011. None. Primary outcome Apgar score <4; secondary outcomes Apgar score <7, intrauterine fetal death, perinatal mortality, congenital anomalies, small for gestational age, asphyxia related morbidity, and cesarean delivery. The risks of birth asphyxia and related morbidity were calculated in women who conceived either through MAR or spontaneously (SC), with a subgroup analysis for in vitro fertilization (IVF). An additional propensity score matching analysis was performed with matching on multiple maternal baseline covariates (maternal age, ethnicity, socioeconomic status, parity, year of birth, and preexistent diseases). Each MAR pregnancy was matched to three SC controls. Relative to SC, the MAR singletons had an increased risk of adverse neonatal outcomes including Apgar score <4 (adjusted odds ratio [OR] 1.29; 95% CI, 1.14-1.46) and intrauterine fetal death (adjusted OR 1.61; 95% CI, 1.35-1.91). After propensity score matching, the risk of an Apgar score <4 was comparable between MAR and SC singletons (OR 0.99; 95% CI, 0.87-1.14). Cesarean delivery for both fetal distress and nonprogressive labor occurred more among MAR pregnancies compared with SC pregnancies. Term singletons conceived after MAR have an increased risk of morbidity related to birth asphyxia. Because this is mainly due to maternal characteristics, obstetric caregivers should be aware that the increased rates of cesareans reflect the behavior of women and physicians rather than increased perinatal complications. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Rigorous Training of Dogs Leads to High Accuracy in Human Scent Matching-To-Sample Performance

PubMed Central

Marchal, Sophie; Bregeras, Olivier; Puaux, Didier; Gervais, Rémi; Ferry, Barbara

2016-01-01

Human scent identification is based on a matching-to-sample task in which trained dogs are required to compare a scent sample collected from an object found at a crime scene to that of a suspect. Based on dogs’ greater olfactory ability to detect and process odours, this method has been used in forensic investigations to identify the odour of a suspect at a crime scene. The excellent reliability and reproducibility of the method largely depend on rigor in dog training. The present study describes the various steps of training that lead to high sensitivity scores, with dogs matching samples with 90% efficiency when the complexity of the scents presented during the task in the sample is similar to that presented in the in lineups, and specificity reaching a ceiling, with no false alarms in human scent matching-to-sample tasks. This high level of accuracy ensures reliable results in judicial human scent identification tests. Also, our data should convince law enforcement authorities to use these results as official forensic evidence when dogs are trained appropriately. PMID:26863620

Performance and Return to Sport After Sports Hernia Surgery in NFL Players

PubMed Central

Jack, Robert A.; Evans, David C.; Echo, Anthony; McCulloch, Patrick C.; Lintner, David M.; Varner, Kevin E.; Harris, Joshua D.

2017-01-01

Background: Recognition, diagnosis, and treatment of athletic pubalgia (AP), also known as sports hernia, once underrecognized and undertreated in professional football, are becoming more common. Surgery as the final treatment for sports hernia when nonsurgical treatment fails remains controversial. Given the money involved and popularity of the National Football League (NFL), it is important to understand surgical outcomes in this patient population. Hypothesis: After AP surgery, players would: (1) return to sport (RTS) at a greater than 90% rate, (2) play fewer games for fewer years than matched controls, (3) have no difference in performance compared with before AP surgery, and (4) have no difference in performance versus matched controls. Study Design: Cohort study; Level of evidence, 3. Methods: Internet-based injury reports identified players who underwent AP surgery from January 1996 to August 2015. Demographic and performance data were collected for each player. A 1:1 matched control group and an index year analog were identified. Control and case performance scores were calculated using a standardized scoring system. Groups were compared using paired Student t tests. Results: Fifty-six NFL players (57 AP surgeries) were analyzed (mean age, 28.2 ± 3.1 years; mean years in NFL at surgery, 5.4 ± 3.2). Fifty-three players were able to RTS. Controls were in the NFL longer (P < .05) than players who underwent AP surgery (3.8 ± 2.4 vs 3.2 ± 2.1 years). Controls played more games per season (P < .05) than post-AP players (14.0 ± 2.3 vs 12.0 ± 3.4 games per season). There was no significant (P > .05) difference in pre- versus post-AP surgery performance scores and no significant (P > .05) difference in postoperative performance scores versus controls post-index. Conclusion: There was a high RTS rate after AP surgery without a significant difference in postoperative performance, though career length and games per season after AP surgery were significantly less than that of matched controls. PMID:28451612

Cold snare polypectomy reduced delayed postpolypectomy bleeding compared with conventional hot polypectomy: a propensity score-matching analysis

PubMed Central

Yamashina, Takeshi; Fukuhara, Manabu; Maruo, Takanori; Tanke, Gensho; Marui, Saiko; Sada, Ryota; Taki, Mio; Ohara, Yoshiaki; Sakamoto, Azusa; Henmi, Shinichiro; Sawai, Yugo; Saito, Sumio; Nishijima, Norihiro; Nasu, Akihiro; Komekado, Hideyuki; Sekikawa, Akira; Asada, Masanori; Tumura, Takehiko; Kita, Ryuichi; Kimura, Toru; Osaki, Yukio

2017-01-01

Background and study aims  Cold snare polypectomy (CSP) for small colorectal polyps has lower incidence of adverse events, especially delayed postpolypectomy bleeding (DPPB). However, few data are available on comparisons of the incidence of DPPB of CSP and hot polypectomy (HP). The aim of this study was to evaluate the incidence of DPPB after CSP and compare it with that of HP. A propensity score model was used as a secondary analysis. Patients and methods  This was a retrospective cohort study conducted in a single municipal hospital. We identified 539 patients with colorectal polyps from 2 mm to 11 mm in size who underwent CSP (804 polyps in 330 patients) or HP (530 polyps in 209 patients) between July 2013 and June 2015. Results  There were no cases of DPPB in the CSP group. Conversely, DPPB occurred in 4 patients (1.9 %) after HP, resulting in a significant difference between the CSP and HP groups (0.008 % vs 0 %, P  = 0.02). Propensity score-matching analysis created 402 matched pairs, yielding a significantly higher DPPB rate in the HP group than CSP group (0.02 % vs 0 %, P  = 0.04). However, significantly more patients in the CSP group had unclear horizontal margins that precluded assessment (83 vs 38 cases, P  < 0.001). The retrieval failure rate was significantly higher in the CSP group than in the HP group (3 % vs 0.7 %, P  = 0.01). Conclusions  DPPB was less frequent with CSP than HP, as selected by the propensity score-matching model. Our findings indicate that CSP is recommended polypectomy in daily clinical setting. However, special care should be taken during polyp retrieval and horizontal margin assessment, and these issues could be taken into account in follow-up after CSP. PMID:28670615

Academic Characteristics of Orthopaedic Surgery Residency Applicants from 2007 to 2014.

PubMed

DePasse, J Mason; Palumbo, Mark A; Eberson, Craig P; Daniels, Alan H

2016-05-04

Based on a relatively stable match rate, several authors have concluded that the competition for orthopaedic residency positions has not changed over the past 3 decades. However, the objective measures of applicant competitiveness have not been quantified in detail. National Resident Matching Program (NRMP) data from 2007 to 2014 for U.S. orthopaedic surgery applicants were compared with data for applicants to all specialties. Trends in the United Stated Medical Licensing Examination (USMLE) Step-1 and Step-2 scores, publications and research experiences, Alpha Omega Alpha (AOA) status, and the presence of an advanced degree are reported. From 2007 to 2014, the match rate for orthopaedic surgery applicants remained stable near 80% (p = 0.14). For orthopaedic applicants who matched, the mean USMLE Step-1 scores increased from 234 points in 2007 to 245 points in 2014 (p = 0.005), and the mean scores increased from 220 points in 2007 to 229 points in 2014 for all applicants (p = 0.019). The mean USMLE Step-2 scores of orthopaedic applicants who matched increased from 235 points in 2007 to 251 points in 2014 (p = 0.005), and the mean scores of all applicants increased from 225 points in 2007 to 242 points in 2014 (p = 0.002). The mean number of research publications, presentations, and abstracts reported by orthopaedic applicants who matched more than doubled from 3.0 in 2007 to 6.7 in 2014 (p = 0.02) and increased less dramatically for all applicants from 2.2 in 2007 to 4.2 in 2014 (p = 0.004). The percentage of orthopaedic applicants elected to AOA or with advanced degrees did not significantly change (p > 0.2). Although orthopaedic applicants with AOA status experienced a very high match rate (97.1% in 2014), those with advanced degrees experienced match rates similar to or slightly lower than the applicant pool (73.7% in 2014). The USMLE Step-1 and 2 scores of U.S. orthopaedic surgery residency applicants have increased significantly from 2007 to 2014. Additionally, the number of publications and presentations reported by orthopaedic applicants has more than doubled. These factors signal an increasing level of academic accomplishment in orthopaedic surgery applicants despite a consistent match rate. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

75 FR 60478 - In the Matter of Certain Machine Vision Software, Machine Vision Systems, and Products Containing...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-30

... Automation, Inc. (``Amistar'') of San Marcos, California; Techno Soft Systemnics, Inc. (``Techno Soft'') of... the claim terms ``test,'' ``match score surface,'' and ``gradient direction,'' all of his infringement... complainants' proposed construction for the claim terms ``test,'' ``match score surface,'' and ``gradient...

Developing Conceptions of Authority and Contract across the Lifespan: Two Perspectives.

ERIC Educational Resources Information Center

Dawson, Theo L.; Gabrielian, Sonya

2003-01-01

Compares concepts defining Kohlbergian stages of moral development with those associated with orders of hierarchical complexity determined with a generalized content-independent stage-scoring system. Finds that Kohlberg's sequence generally matches that identified with the scoring system and that contract and authority concepts match the concepts…

Balancing Score Adjusted Targeted Minimum Loss-based Estimation

PubMed Central

Lendle, Samuel David; Fireman, Bruce; van der Laan, Mark J.

2015-01-01

Adjusting for a balancing score is sufficient for bias reduction when estimating causal effects including the average treatment effect and effect among the treated. Estimators that adjust for the propensity score in a nonparametric way, such as matching on an estimate of the propensity score, can be consistent when the estimated propensity score is not consistent for the true propensity score but converges to some other balancing score. We call this property the balancing score property, and discuss a class of estimators that have this property. We introduce a targeted minimum loss-based estimator (TMLE) for a treatment-specific mean with the balancing score property that is additionally locally efficient and doubly robust. We investigate the new estimator’s performance relative to other estimators, including another TMLE, a propensity score matching estimator, an inverse probability of treatment weighted estimator, and a regression-based estimator in simulation studies. PMID:26561539

Analyzing Propensity Matched Zero-Inflated Count Outcomes in Observational Studies

PubMed Central

DeSantis, Stacia M.; Lazaridis, Christos; Ji, Shuang; Spinale, Francis G.

2013-01-01

Determining the effectiveness of different treatments from observational data, which are characterized by imbalance between groups due to lack of randomization, is challenging. Propensity matching is often used to rectify imbalances among prognostic variables. However, there are no guidelines on how appropriately to analyze group matched data when the outcome is a zero inflated count. In addition, there is debate over whether to account for correlation of responses induced by matching, and/or whether to adjust for variables used in generating the propensity score in the final analysis. The aim of this research is to compare covariate unadjusted and adjusted zero-inflated Poisson models that do and do not account for the correlation. A simulation study is conducted, demonstrating that it is necessary to adjust for potential residual confounding, but that accounting for correlation is less important. The methods are applied to a biomedical research data set. PMID:24298197

Optimal Utilization of Donor Grafts With Extended Criteria

PubMed Central

Cameron, Andrew M.; Ghobrial, R Mark; Yersiz, Hasan; Farmer, Douglas G.; Lipshutz, Gerald S.; Gordon, Sherilyn A.; Zimmerman, Michael; Hong, Johnny; Collins, Thomas E.; Gornbein, Jeffery; Amersi, Farin; Weaver, Michael; Cao, Carlos; Chen, Tony; Hiatt, Jonathan R.; Busuttil, Ronald W.

2006-01-01

Objective: Severely limited organ resources mandate maximum utilization of donor allografts for orthotopic liver transplantation (OLT). This work aimed to identify factors that impact survival outcomes for extended criteria donors (ECD) and developed an ECD scoring system to facilitate graft-recipient matching and optimize utilization of ECDs. Methods: Retrospective analysis of over 1000 primary adult OLTs at UCLA. Extended criteria (EC) considered included donor age (>55 years), donor hospital stay (>5 days), cold ischemia time (>10 hours), and warm ischemia time (>40 minutes). One point was assigned for each extended criterion. Cox proportional hazard regression model was used for multivariate analysis. Results: Of 1153 allografts considered in the study, 568 organs exhibited no extended criteria (0 score), while 429, 135 and 21 donor allografts exhibited an EC score of 1, 2 and 3, respectively. Overall 1-year patient survival rates were 88%, 82%, 77% and 48% for recipients with EC scores of 0, 1, 2 and 3 respectively (P < 0.001). Adjusting for recipient age and urgency at the time of transplantation, multivariate analysis identified an ascending mortality risk ratio of 1.4 and 1.8 compared to a score of 0 for an EC score of 1, and 2 (P < 0.01) respectively. In contrast, an EC score of 3 was associated with a mortality risk ratio of 4.5 (P < 0.001). Further, advanced recipient age linearly increased the death hazard ratio, while an urgent recipient status increased the risk ratio of death by 50%. Conclusions: Extended criteria donors can be scored using readily available parameters. Optimizing perioperative variables and matching ECD allografts to appropriately selected recipients are crucial to maintain acceptable outcomes and represent a preferable alternative to both high waiting list mortality and to a potentially futile transplant that utilizes an ECD for a critically ill recipient. PMID:16772778

Influencing Transfer and Baccalaureate Attainment for Community College Students through State Grant Aid: Quasi-Experimental Evidence from Texas

ERIC Educational Resources Information Center

Bordoloi Pazich, Loni

2014-01-01

This study uses statewide longitudinal data from Texas to estimate the impact of a state grant program intended to encourage low-income community college students to transfer to four-year institutions and complete the baccalaureate. Quasi-experimental methods employed include propensity score matching and regression discontinuity. Results indicate…

Co-Curricular Connections: The Role of Undergraduate Research Experiences in Promoting Engineering Students' Communication, Teamwork, and Leadership Skills

ERIC Educational Resources Information Center

Carter, Deborah Faye; Ro, Hyun Kyoung; Alcott, Benjamin; Lattuca, Lisa R.

2016-01-01

This study examined the impact of undergraduate research (UR) in engineering, focusing on three particular learning outcomes: communication, teamwork, and leadership. The study included 5126 students across 31 colleges of engineering. The authors employed propensity score matching method to address the selection bias for selection into (and…

Does the Consecutive Interpreting Approach enhance medical English communication skills of Japanese-speaking students?

PubMed

Iizuka, Hideki; Lefor, Alan K

2018-04-19

To determine if the Consecutive Interpreting Approach enhances medical English communication skills of students in a Japanese medical university and to assess this method based on performance and student evaluations.  This is a three-phase study using a mixed-methods design, which starts with four language reproduction activities for 30 medical and 95 nursing students, followed by a quantitative analysis of perfect-match reproduction rates to assess changes over the duration of the study and qualitative error analysis of participants' language reproduction. The final stage included a scored course evaluation and free-form comments to evaluate this approach and to identify effective educational strategies to enhance medical English communication skills. Mean perfect-match reproduction rates of all participants over four reproduction activities differed statistically significantly (repeated measures ANOVA, p<0.0005). The overall perfect-match reproduction rates improved from 75.3 % to 90.1 % for nursing and 89.5 % to 91.6% for medical students. The final achievement levels of nursing and medical students were equivalent (test of equivalence, p<0.05). Details of lexical- and syntactic-level errors were identified. The course evaluation scores were 3.74 (n=30, SD = 0.59) and 3.77 (n=90, SD=0.54) for medical and nursing students respectively. Participants' medical English communication skills are enhanced using this approach. Participants expressed positive feedback regarding this instruction method. This approach may be effective to enhance the language skills of non-native English-speaking students seeking to practice medicine in English speaking countries.

Emergency coronary artery bypass grafting using minimized versus standard extracorporeal circulation – a propensity score analysis

PubMed Central

2013-01-01

Background The impact of minimized extracorporeal circulation (MECC) for emergency revascularization remains controversial. Methods A total of 348 patients underwent emergency CABG with MECC (n=146) or conventional extracorporeal circulation (CECC; n=175) between January 2005 and December 2010. Using propensity score matching after binary logistic regression, 100 patients, who underwent CABG with MECC could be matched with 100 patients, who underwent CABG with CECC. Primary outcome was 30-day mortality. Results Unadjusted 30-day mortality was 14.8% in patients with CECC and 6.9% in those with MECC (mean difference −7.9%; p=0.03). The adjusted mean difference (average treatment effect of the treated, ATT) after matching was −1.0% (95% CI −8.6 to 7.6; p=1.0). Intensive care unit stay (adjusted mean difference 1.0; 95% CI −0.2 to 3.2; p=0.70) and hospital stay (adjusted mean difference 1.0; 95% CI −2.0 to 3.6; p=0.40) did not show significant differences between both groups. The adjusted mean difference for postoperative low cardiac output syndrome was −1.1% (95% CI −7.3 to 7.1; p=0.83) without significant differences between CECC and MECC. Postoperative mechanical ventilation time, drain loss, postoperative rethoracotomy, postoperative neurological events, new onset renal replacement therapy and respiratory failure also had insignificant average treatment effects of the treated. In addition, all average treatment effects (ATEs) did not significantly differ between both groups. Conclusion Using propensity score estimation and matching, we did not observe significant differences in terms of survival and further outcomes in patients who undergo emergency CABG with CECC or MECC, but our results call for further analysis. PMID:23547910

Comparison of the effect of endodontic-periodontal combined lesion on the outcome of endodontic microsurgery with that of isolated endodontic lesion: survival analysis using propensity score analysis.

PubMed

Song, Minju; Kang, Minji; Kang, Dae Ryong; Jung, Hoi In; Kim, Euiseong

2018-05-01

The purpose of this retrospective clinical study was to evaluate the effect of lesion types related to endodontic microsurgery on the clinical outcome. Patients who underwent endodontic microsurgery between March 2001 and March 2014 with a postoperative follow-up period of at least 1 year were included in the study. Survival analyses were conducted to compare the clinical outcomes between isolated endodontic lesion group (endo group) and endodontic-periodontal combined lesion group (endo-perio group) and to evaluate other clinical variables. To reduce the effect of selection bias in this study, the estimated propensity scores were used to match the cases of the endo group with those of the endo-perio group. Among the 414 eligible cases, the 83 cases in the endo-perio group were matched to 166 out of the 331 cases in the endo group based on propensity score matching (PSM). The cumulated success rates of the endo and endo-perio groups were 87.3 and 72.3%, respectively. The median success period of the endo-perio group was 12 years (95% CI: 5.507, 18.498). Lesion type was found to be significant according to both Log-rank test (P = 0.002) and Cox proportional hazard regression analysis (P = 0.001). Among the other clinical variables, sex (female or male), age, and tooth type (anterior, premolar, or molar) were determined to be significant in Cox regression analysis (P < 0.05). Endodontic-periodontal combined lesions had a negative effect on the clinical outcome based on an analysis that utilized PSM, a useful statistical matching method for observational studies. Lesion type is a significant predictor of the outcome of endodontic microsurgery.

Clinicopathologic Characteristics and Prognosis of Xp11.2 Translocation Renal Cell Carcinoma: Multicenter, Propensity Score Matching Analysis.

PubMed

Choo, Min Soo; Jeong, Chang Wook; Song, Cheryn; Jeon, Hwang Gyun; Seo, Seong Il; Hong, Sung Kyu; Byun, Seok-Soo; Chung, Jin Soo; Hong, Sung-Hoo; Hwang, Eu Chang; Kim, Hyeon Hoe; Kwak, Cheol

2017-10-01

We evaluated the clinicopathologic characteristics and prognosis of Xp11.2 translocation (Xp11.2t) renal cell carcinoma (RCC) from a multicenter study and compare them with clear-cell RCC using a propensity score matching analysis. Between 2004 and 2013, 8384 consecutive patients from 7 institutions who were diagnosed with RCC were reviewed, and the pathologically confirmed Xp11.2t cases were enrolled. The oncological outcomes of Xp11.2t were compared with those of clear-cell RCC by selecting matched cases using 1:3 propensity score matching methods in a precollected clear-cell RCC data set from our hospital. The patients were divided into 2 subgroups on the basis of age of onset, either before (early) or after (late) 45 years old. Xp11.2t was found in 61 cases, corresponding to 0.72% of RCC cases for the 10 years. The mean age was 38.2 ± 19.4 years, and the mean tumor size was 6.2 ± 3.9 cm. The Xp11.2t cases were at more advanced stages and showed tendencies to involve lymph nodes at diagnosis. After the matching, there were no significant differences in recurrence-free and overall survival compared with clear-cell RCC. The age of incidence for Xp11.2t had a bimodal distribution, which was most common in the 30s and smaller peak in the 60s. Xp11.2t corresponded to a significantly worse prognosis for overall survival in late onset (after 45 years) subgroup (P = .038; hazard ratio, 3.199; 95% confidence interval, 1.065-9.609). This neoplasm has more aggressive clinicopathologic features at diagnosis. In older patients with onset age > 45 years, Xp11.2t showed a significantly worse prognosis than clear-cell RCC. Copyright © 2017 Elsevier Inc. All rights reserved.

Perioperative and mid-term oncologic outcomes of robotic assisted radical cystectomy with totally intracorporeal neobladder: Results of a propensity score matched comparison with open cohort from a single-centre series.

PubMed

Simone, Giuseppe; Tuderti, Gabriele; Misuraca, Leonardo; Anceschi, Umberto; Ferriero, Mariaconsiglia; Minisola, Francesco; Guaglianone, Salvatore; Gallucci, Michele

2018-04-17

In this study, we compared perioperative and oncologic outcomes of patients treated with either open or robot-assisted radical cystectomy and intracorporeal neobladder at a tertiary care center. The institutional prospective bladder cancer database was queried for "cystectomy with curative intent" and "neobladder". All patients underwent robot-assisted radical cystectomy and intracorporeal neobladder or open radical cystectomy and orthotopic neobladder for high-grade non-muscle invasive bladder cancer or muscle invasive bladder cancer with a follow-up length ≥2 years were included. A 1:1 propensity score matching analysis was used. Kaplan-Meier method was performed to compare oncologic outcomes of selected cohorts. Survival rates were computed at 1,2,3 and 4 years after surgery and the log rank test was applied to assess statistical significance between the matched groups. Overall, 363 patients (299 open and 64 robotic) were included. Open radical cystectomy patients were more frequently male (p = 0.08), with higher pT stages (p = 0.003), lower incidence of urothelial histologies (p = 0.05) and lesser adoption of neoadjuvant chemotherapy (<0.001). After applying the propensity score matching, 64 robot-assisted radical cystectomy patients were matched with 46 open radical cystectomy cases (all p ≥ 0.22). Open cohort showed a higher rate of perioperative overall complications (91.3% vs 42.2%, p 0.001). At Kaplan-Meier analysis robotic and open cohorts displayed comparable disease-free survival (log-rank p = 0.746), cancer-specific survival (p = 0.753) and overall-survival rates (p = 0.909). Robot-assisted radical cystectomy and intracorporeal neobladder provides comparable oncologic outcomes of open radical cystectomy and orthotopic neobladder at intermediate term survival analysis. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Using Propensity Score Matching to Test the Community College Penalty Assumption

ERIC Educational Resources Information Center

Dietrich, Cecile C.; Lichtenberger, Eric J.

2015-01-01

Research studies have been ambivalent about whether enrolling in community college makes completing a bachelor's degree less likely than directly enrolling in a four-year institution. This study uses propensity score matching with a posttreatment adjustment to determine the treatment effect associated with taking the community college to four-year…

The association between the availability of sugar-sweetened beverage in school vending machines and its consumption among adolescents in California: a propensity score matching approach.

PubMed

Shi, Lu

2010-01-01

There is controversy over to what degree banning sugar-sweetened beverage (SSB) sales at schools could decrease the SSB intake. This paper uses the adolescent sample of 2005 California Health Interview Survey to estimate the association between the availability of SSB from school vending machines and the amount of SSB consumption. Propensity score stratification and kernel-based propensity score matching are used to address the selection bias issue in cross-sectional data. Propensity score stratification shows that adolescents who had access to SSB through their school vending machines consumed 0.170 more drinks of SSB than those who did not (P < .05). Kernel-based propensity score matching shows the SSB consumption difference to be 0.158 on the prior day (P < .05). This paper strengthens the evidence for the association between SSB availability via school vending machines and the actual SSB consumption, while future studies are needed to explore changes in other beverages after SSB becomes less available.

Influence of Color Education and Training on Shade Matching Skills.

PubMed

Ristic, Ivan; Stankovic, Sasa; Paravina, Rade D

2016-09-01

To evaluate the influence of education and training on quality of tooth color matching. Dental students (N = 174), matched the color of eight shade tabs in a viewing booth, using VITA Linearguide 3D-Master shade guide. The experimental group had color education and training between the before and after session. The control group did not have any additional information in between two sessions. Color differences between the task tabs and selected tabs were calculated using CIE formulas. The score for the best match (smallest color difference) was 10 points, the 2nd best match 9 points, down to 1 point for the 10th best match. Means and standard deviations were calculated. Differences were analyzed using the Student t-test. Shade matching scores in the experimental group were significantly better after education and training (p < 0.001), with a mean score before and after shade matching sessions of 7.06 (1.19) and 8.43 (0.92), respectively. The percentage of students in the experimental group that selected one of three best matches increased 24.3%. The control group exhibited no significant improvement in the after session. Within the limitations of the study, education and training improved students' shade matching skills. While the vast majority of dental restorations and practically all restorations in the esthetic zone are tooth colored, the profession as a whole is far from perfect when it comes to accurate shade matching. Education and training can improve shade matching ability: enhanced esthetics of dental restorations, increased patient satisfaction, and a reduced number of color corrections are some of the notable benefits and rewards. (J Esthet Restor Dent 00:000-000, 2016) J Esthet Restor Dent 28:287-294, 2016). © 2016 Wiley Periodicals, Inc.

Explicit Consideration of Baseline Factors to Assess Recombinant Tissue-Type Plasminogen Activator Response With Respect to Race and Sex

PubMed Central

Mandava, Pitchaiah; Murthy, Santosh B.; Munoz, Melody; McGuire, Dawn; Simon, Roger P.; Alexandrov, Andrei V.; Albright, Karen C.; Boehme, Amelia K.; Martin-Schild, Sheryl; Martini, Sharyl; Kent, Thomas A.

2017-01-01

Background and Purpose Sex and race reportedly influence outcome after recombinant tissue-type plasminogen activator (rtPA). It is, however, unclear whether baseline imbalances (eg, stroke severity) or lack of response to thrombolysis is responsible. We applied balancing methods to test the hypothesis that race and sex influence outcome after rtPA independent of baseline conditions. Methods We mapped group outcomes from the National Institute of Neurological Disorders and Stroke (NINDS) dataset based on race and sex onto a surrogate-control function to assess differences from expected outcomes at their respective National Institutes of Health Stroke Scale and age. Outcomes were also compared for subjects matched individually on key baseline factors using NINDS and 2 recent datasets from southeastern United States. Results At similar National Institutes of Health Stroke Scale and age, 90-day good outcomes (modified Rankin Score, 0–2) in NINDS were similarly improved after rtPA for white men and women. There was a strong trend for improvement in black men. Conversely, black women treated with rtPA showed response rates no different from the controls. After baseline matching, there were nonsignificant trends in outcomes except for significantly fewer good outcomes in black versus matched white women (37% versus 63%; P=0.027). Pooling the 3 datasets showed a similar trend for poorer short-term outcome for black women (P=0.054; modified Rankin Score, 0–1). Conclusions Matching for key baseline factors indicated that race and sex influence outcome most strikingly in black women who demonstrated poorest outcomes after rtPA. This finding supports the hypothesis that poor response to rtPA, rather than differences in baseline conditions, contributes to the worse outcome. This finding requires prospective confirmation. PMID:23674524

Spironolactone Treatment and Effect on Survival in Chronic Heart Failure Patients with Reduced Renal Function: A Propensity-Matched Study

PubMed Central

Stubnova, Viera; Os, Ingrid; Grundtvig, Morten; Atar, Dan; Waldum-Grevbo, Bård

2017-01-01

Background/Aims Spironolactone may be hazardous in heart failure (HF) patients with renal dysfunction due to risk of hyperkalemia and worsened renal function. We aimed to evaluate the effect of spironolactone on all-cause mortality in HF outpatients with renal dysfunction in a propensity-score-matched study. Methods A total of 2,077 patients from the Norwegian Heart Failure Registry with renal dysfunction (eGFR <60 mL/min/1.73 m2) not treated with spironolactone at the first visit at the HF clinic were eligible for the study. Patients started on spironolactone at the outpatient HF clinics (n = 206) were propensity-score-matched 1:1 with patients not started on spironolactone, based on 16 measured baseline characteristics. Kaplan-Meier and Cox regression analyses were used to investigate the independent effect of spironolactone on 2-year all-cause mortality. Results Propensity score matching identified 170 pairs of patients, one group receiving spironolactone and the other not. The two groups were well matched (mean age 76.7 ± 8.1 years, 66.4% males, and eGFR 46.2 ± 10.2 mL/min/1.73 m2). Treatment with spironolactone was associated with increased potassium (delta potassium 0.31 ± 0.55 vs. 0.05 ± 0.41 mmol/L, p < 0.001) and decreased eGFR (delta eGFR −4.12 ± 12.2 vs. −0.98 ± 7.88 mL/min/1.73 m2, p = 0.006) compared to the non-spironolactone group. After 2 years, 84% of patients were alive in the spironolactone group and 73% of patients in the non-spironolactone group (HR 0.59, 95% CI 0.37-0.92, p = 0.020). Conclusion In HF outpatients with renal dysfunction, treatment with spironolactone was associated with improved 2-year survival compared to well-matched patients not treated with spironolactone. Favorable survival was observed despite worsened renal function and increased potassium in the spironolactone group. PMID:28611786

Delayed matching to two-picture samples by individuals with and without disabilities: an analysis of the role of naming.

PubMed

Gutowski, Stanley J; Stromer, Robert

2003-01-01

Delayed matching to complex, two-picture samples (e.g., cat-dog) may be improved when the samples occasion differential verbal behavior. In Experiment 1, individuals with mental retardation matched picture comparisons to identical single-picture samples or to two-picture samples, one of which was identical to a comparison. Accuracy scores were typically high on single-picture trials under both simultaneous and delayed matching conditions. Scores on two-picture trials were also high during the simultaneous condition but were lower during the delay condition. However, scores improved on delayed two-picture trials when each of the sample pictures was named aloud before comparison responding. Experiment 2 replicated these results with preschoolers with typical development and a youth with mental retardation. Sample naming also improved the preschoolers' matching when the samples were pairs of spoken names and the correct comparison picture matched one of the names. Collectively, the participants could produce the verbal behavior that might have improved performance, but typically did not do so unless the procedure required it. The success of the naming intervention recommends it for improving the observing and remembering of multiple elements of complex instructional stimuli.

Tibial lengthening over intramedullary nails

PubMed Central

Burghardt, R. D.; Manzotti, A.; Bhave, A.; Paley, D.

2016-01-01

Objectives The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. Methods In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group. Results The mean external fixation time for the LON group was 2.6 months and for the matched case group was 7.6 months. The mean lengthening amounts for the LON and the matched case groups were 5.2 cm and 4.9 cm, respectively. The radiographic consolidation time in the LON group was 6.6 months and in the matched case group 7.6 months. Using a clinical and radiographic outcome score that was designed for this study, the outcome was determined to be excellent in 17 and good in two patients for the LON group. The outcome was excellent in 14 and good in five patients in the matched case group. The LON group had increased blood loss and increased cost. The LON group had four deep infections; the matched case group did not have any deep infections. Conclusions The outcomes in the LON group were comparable with the outcomes in the matched case group. The LON group had a shorter external fixation time but experienced increased blood loss, increased cost, and four cases of deep infection. The advantage of reducing external fixation treatment time may outweigh these disadvantages in patients who have a healthy soft-tissue envelope. Cite this article: J. E. Herzenberg. Tibial lengthening over intramedullary nails: A matched case comparison with Ilizarov tibial lengthening. Bone Joint Res 2016;5:1–10. doi: 10.1302/2046-3758.51.2000577 PMID:26764351

Impact of nutrition support on clinical outcome and cost-effectiveness analysis in patients at nutritional risk: A prospective cohort study with propensity score matching.

PubMed

Zhang, Hui; Wang, Yang; Jiang, Zhu-Ming; Kondrup, Jens; Fang, Hai; Andrews, Martha; Nolan, Marie T; Mu, Shao-Yu; Zhang, Jun; Yu, Kang; Lu, Qian; Kang, Wei-Ming

2017-05-01

There is a lack of evidence regarding the economic effects of nutrition support in patients at nutritional risk. The aim of this study was to perform a cost-effectiveness analysis by comparing an adequate nutrition support cohort with a no-support cohort. A prospective observational study was performed in the surgical and medical gastroenterology wards. We identified patients at nutritional risk and the provision of nutrition support by the staff, unaware of the risk status, was recorded. Cost data were obtained from each patient's statement of accounts, and effectiveness was measured by the rate of infectious complication. To control for potential confounding variables, the propensity score method with matching was carried out. The incremental cost-effectiveness ratio was calculated based on the matched population. We screened 3791 patients, and 440 were recruited for the analysis. Patients in the nutrition support cohort had a lower incidence of infectious complications than those in the no-support cohort (9.1 versus 18.1%; P = 0.007). This result was similar in the 149 propensity matched pairs (9.4 versus 24.2%; P < 0.001). The median hospital length of stay was significantly reduced among the matched nutrition support patients (13 versus 15 d; P < 0.001). The total costs were similar among the matched pairs (US $6219 versus $6161). The incremental cost-effectiveness analysis suggested that nutrition support cost US $392 per patient prevented from having infectious complications. Nutrition support was associated with fewer infectious complications and shorter length of stay in patients at nutritional risk. The incremental cost-effectiveness ratio indicated that nutrition support had not increased costs significantly. Copyright © 2016 Elsevier Inc. All rights reserved.

Emergent Literacy in Thai Preschoolers: A Preliminary Study.

PubMed

Yampratoom, Ramorn; Aroonyadech, Nawarat; Ruangdaraganon, Nichara; Roongpraiwan, Rawiwan; Kositprapa, Jariya

To investigate emergent literacy skills, including phonological awareness when presented with an initial phoneme-matching task and letter knowledge when presented with a letter-naming task in Thai preschoolers, and to identify key factors associated with those skills. Four hundred twelve typically developing children in their final kindergarten year were enrolled in this study. Their emergent reading skills were measured by initial phoneme-matching and letter-naming tasks. Determinant variables, such as parents' education and teachers' perception, were collected by self-report questionnaires. The mean score of the initial phoneme-matching task was 4.5 (45% of a total of 10 scores). The mean score of the letter-naming task without a picture representing the target letter name was 30.2 (68.6% of a total of 44 scores), which increased to 38.8 (88.2% of a total of 44 scores) in the letter-naming task when a picture representing the target letter name was provided. Both initial phoneme-matching and letter-naming abilities were associated with the mother's education and household income. Letter-naming ability was also influenced by home reading activities and gender. This was a preliminary study into emergent literacy skills of Thai preschoolers. The findings supported the importance of focusing on phonological awareness and phonics, especially in the socioeconomic disadvantaged group.

Universality in the distance between two teams in a football tournament

NASA Astrophysics Data System (ADS)

da Silva, Roberto; Dahmen, Silvio R.

2014-03-01

Is football (soccer) a universal sport? Beyond the question of geographical distribution, where the answer is most certainly yes, when looked at from a mathematical viewpoint the scoring process during a match can be thought of, in a first approximation, as being modeled by a Poisson distribution. Recently, it was shown that the scoring of real tournaments can be reproduced by means of an agent-based model (da Silva et al. (2013) [24]) based on two simple hypotheses: (i) the ability of a team to win a match is given by the rate of a Poisson distribution that governs its scoring during a match; and (ii) such ability evolves over time according to results of previous matches. In this article we are interested in the question of whether the time series represented by the scores of teams have universal properties. For this purpose we define a distance between two teams as the square root of the sum of squares of the score differences between teams over all rounds in a double-round-robin-system and study how this distance evolves over time. Our results suggest a universal distance distribution of tournaments of different major leagues which is better characterized by an exponentially modified Gaussian (EMG). This result is corroborated by our agent-based model.

Adaptive behavior in Chinese children with Williams syndrome

PubMed Central

2014-01-01

Background Williams syndrome (WS) is a neurodevelopmental disease characterized by compelling psychological phenotypes. The symptoms span multiple cognitive domains and include a distinctive pattern of social behavior. The goal of this study was to explore adaptive behavior in WS patients in China. Methods We conducted a structured interview including the Infants-Junior Middle School Students Social-life Abilities Scale in three participant groups: children with WS (n = 26), normally-developing children matched for mental age (MA, n = 30), and normally-developing children matched for chronological age (CA, n = 40). We compared the mean scores for each domain between the three groups. Results Children with WS had more siblings than children in the two control groups. The educational level of the caregivers of WS children was lower than that of the control children. We found no differences in locomotion, work skill, socialization, or self-management between the WS and MA groups. WS children obtained higher scores of self-dependence (df = 54, Z = −2.379, p = 0.017) and had better communication skills (df = 54, Z = −2.222, p = 0.026) compared with MA children. The CA children achieved higher scores than the WS children for all dimensions of adaptive behavior. Conclusions WS children have better adaptive behavior skills regarding communication and self-dependence than normal children matched for mental age. Targeted intervention techniques should be designed to promote social development in this population. PMID:24708693

The application of differential ratings of perceived exertion to Australian Football League matches.

PubMed

Weston, Matthew; Siegler, Jason; Bahnert, Andrew; McBrien, James; Lovell, Ric

2015-11-01

To investigate the application of differential ratings of perceived exertion for the examination of internal load during Australian Football League (AFL) matches. Single cohort, observational study. Using the centiMax rating of perceived exertion (RPE) scale, 26 professional AFL players provided ratings for match exertion (RPE-M), along with differential ratings for breathlessness (RPE-B), leg exertion (RPE-L), and technical demand (RPE-T) following 129 matches (5.0 ± 1.6 matches per player). Global positioning satellite (GPS) and accelerometer measures were also collected. Data were analysed using magnitude-based inferences. RPE scores were 93.0 ± 8.2 AU (RPE-M), 89.0 ± 11.0 AU (RPE-B), 91.5 ± 9.8 AU (RPE-L), and 87.0 ± 10.0 AU (RPE-T). There was a most likely small difference between RPE-L and RPE-T (5.5%; ± 90% confidence limits 1.9%), a likely small difference between RPE-L and RPE-B (3.5%; ± 1.5%) and a possibly small difference between RPE-B and RPE-T (1.9%; ± 1.9%). Within-player correlations between RPE and GPS measures were small for RPE-M (r = 0.14-0.28), unclear to small for RPE-B (r = 0.06-0.24) and unclear to moderate for RPE-L (r = 0.06-0.37). Differential RPE's combined to explain 76% of the variance in RPE-M. For all RPE scores, within-player variability was moderate to high (typical error: 7.9-12.4%), and the thresholds for a likely between-match change were 8.8-13.7%. As differential RPE's represent distinct sensory inputs, the collection of these scores facilitate the interpretation of internal match loads and therefore represent a valuable addition to match data collection procedures. Moderate to high within-player variability should be considered when interpreting between-match changes in all RPE scores. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The use of propensity score methods with survival or time-to-event outcomes: reporting measures of effect similar to those used in randomized experiments.

PubMed

Austin, Peter C

2014-03-30

Propensity score methods are increasingly being used to estimate causal treatment effects in observational studies. In medical and epidemiological studies, outcomes are frequently time-to-event in nature. Propensity-score methods are often applied incorrectly when estimating the effect of treatment on time-to-event outcomes. This article describes how two different propensity score methods (matching and inverse probability of treatment weighting) can be used to estimate the measures of effect that are frequently reported in randomized controlled trials: (i) marginal survival curves, which describe survival in the population if all subjects were treated or if all subjects were untreated; and (ii) marginal hazard ratios. The use of these propensity score methods allows one to replicate the measures of effect that are commonly reported in randomized controlled trials with time-to-event outcomes: both absolute and relative reductions in the probability of an event occurring can be determined. We also provide guidance on variable selection for the propensity score model, highlight methods for assessing the balance of baseline covariates between treated and untreated subjects, and describe the implementation of a sensitivity analysis to assess the effect of unmeasured confounding variables on the estimated treatment effect when outcomes are time-to-event in nature. The methods in the paper are illustrated by estimating the effect of discharge statin prescribing on the risk of death in a sample of patients hospitalized with acute myocardial infarction. In this tutorial article, we describe and illustrate all the steps necessary to conduct a comprehensive analysis of the effect of treatment on time-to-event outcomes. © 2013 The authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Acceleration in Elementary School: Using Propensity Score Matching to Estimate the Effects on Academic Achievement

ERIC Educational Resources Information Center

Kretschmann, Julia; Vock, Miriam; Lüdtke, Oliver

2014-01-01

Using German data, we examined the effects of one specific type of acceleration--grade skipping--on academic performance. Prior research on the effects of acceleration has suffered from methodological restrictions, especially due to a lack of appropriate comparison groups and a priori measurements. For this reason, propensity score matching was…

Impacts of Playing after School on Academic Performance: A Propensity Score Matching Approach

ERIC Educational Resources Information Center

Li, Yajuan; Palma, Marco A.; Xu, Zhicheng Phil

2017-01-01

We present a plausible causal analysis of the impact of playing after school on academic performance and investigate parental support as a potential channel. We exploit the data from the 2011 Trends in International Mathematics and Science Survey to evaluate the effects by using a propensity score matching approach. The results show that playing…

Multicenter Validation of a Customizable Scoring Tool for Selection of Trainees for a Residency or Fellowship Program. The EAST-IST Study.

PubMed

Bosslet, Gabriel T; Carlos, W Graham; Tybor, David J; McCallister, Jennifer; Huebert, Candace; Henderson, Ashley; Miles, Matthew C; Twigg, Homer; Sears, Catherine R; Brown, Cynthia; Farber, Mark O; Lahm, Tim; Buckley, John D

2017-04-01

Few data have been published regarding scoring tools for selection of postgraduate medical trainee candidates that have wide applicability. The authors present a novel scoring tool developed to assist postgraduate programs in generating an institution-specific rank list derived from selected elements of the U.S. Electronic Residency Application System (ERAS) application. The authors developed and validated an ERAS and interview day scoring tool at five pulmonary and critical care fellowship programs: the ERAS Application Scoring Tool-Interview Scoring Tool. This scoring tool was then tested for intrarater correlation versus subjective rankings of ERAS applications. The process for development of the tool was performed at four other institutions, and it was performed alongside and compared with the "traditional" ranking methods at the five programs and compared with the submitted National Residency Match Program rank list. The ERAS Application Scoring Tool correlated highly with subjective faculty rankings at the primary institution (average Spearman's r = 0.77). The ERAS Application Scoring Tool-Interview Scoring Tool method correlated well with traditional ranking methodology at all five institutions (Spearman's r = 0.54, 0.65, 0.72, 0.77, and 0.84). This study validates a process for selecting and weighting components of the ERAS application and interview day to create a customizable, institution-specific tool for ranking candidates to postgraduate medical education programs. This scoring system can be used in future studies to compare the outcomes of fellowship training.

Physical Disabilities Related to the Depressive Mental States of Japanese Patients with Subacute Myelo-optico-neuropathy.

PubMed

Konishi, Tetsuro

2018-05-18

Objective The aim of this study was to clarify the clinical conditions related to the depressive mental states in Japanese patients with subacute myelo-optico-neuropathy (SMON), caused by clioquinol intoxication more than 40 years previously. Materials and methods The changes in the mental states with aging were investigated in 25 Japanese SMON patients (mean age: 77.2 years old, range: 53-90) using a Japanese version of the Zung Self-rating Depression Scale (J-SDS) questionnaires with supportive interviews by the clinical psychotherapist and medical checkup records. These mental and medical examinations were repeated more than twice within 2 to 11 years' interval. The J-SDS questionnaires were also examined in 25 age-matched non-SMON elderly people. Results The total J-SDS scores of most of the SMON patients decreased with age without significant changes in the mean Barthel index scores during this study period. The mean J-SDS scores at the first and latest studies were significantly higher than in the age-matched healthy elderly people. The total J-SDS scores of the latest study were significantly correlated with the degree of physical disability, such as the inverse total Barthel index scores, severity of SMON or gait disturbance, but not with the age. Conclusion The total J-SDS scores of most of the SMON patients tended to decrease with age. Repeating mental supportive interviews and medical examinations by experts helped to improve the depressive mental state and revealed close relationship between the mental state and the physical disabilities of the SMON patients.

Does tooth wear status predict ongoing sleep bruxism in 30-year-old Japanese subjects?

PubMed

Baba, Kazuyoshi; Haketa, Tadasu; Clark, Glenn T; Ohyama, Takashi

2004-01-01

This study investigated whether tooth wear status can predict bruxism level. Sixteen Japanese subjects (eight bruxers and eight age- and gender-matched controls; mean age 30 years) participated in this study. From dental casts of these subjects, the tooth wear was scored by Murphy's method. Bruxism level in these subjects was also recorded for 5 consecutive nights in the subject's home environment using a force-based bruxism detecting system. The relationship between the tooth wear score and bruxism data was evaluated statistically. Correlation analysis between the Murphy's scores of maxillary and mandibular dental arch and bruxism event duration score revealed no significant relationship between tooth wear and current bruxism. Tooth wear status is not predictive of ongoing bruxism level as measured by the force-based bruxism detection system in 30-year-old Japanese subjects.

Sentence Recall by Children With SLI Across Two Nonmainstream Dialects of English

PubMed Central

McDonald, Janet L.; Seidel, Christy M.; Hegarty, Michael

2016-01-01

Purpose The inability to accurately recall sentences has proven to be a clinical marker of specific language impairment (SLI); this task yields moderate-to-high levels of sensitivity and specificity. However, it is not yet known if these results hold for speakers of dialects whose nonmainstream grammatical productions overlap with those that are produced at high rates by children with SLI. Method Using matched groups of 70 African American English speakers and 36 Southern White English speakers and dialect-strategic scoring, we examined children's sentence recall abilities as a function of their dialect and clinical status (SLI vs. typically developing [TD]). Results For both dialects, the SLI group earned lower sentence recall scores than the TD group with sensitivity and specificity values ranging from .80 to .94, depending on the analysis. Children with SLI, as compared with TD controls, manifested lower levels of verbatim recall, more ungrammatical recalls when the recall was not exact, and higher levels of error on targeted functional categories, especially those marking tense. Conclusion When matched groups are examined and dialect-strategic scoring is used, sentence recall yields moderate-to-high levels of diagnostic accuracy to identify SLI within speakers of nonmainstream dialects of English. PMID:26501934

Propensity score matching of the gymnastics for diabetes mellitus using logistic regression

NASA Astrophysics Data System (ADS)

Otok, Bambang Widjanarko; Aisyah, Amalia; Purhadi, Andari, Shofi

2017-12-01

Diabetes Mellitus (DM) is a group of metabolic diseases with characteristics shows an abnormal blood glucose level occurring due to pancreatic insulin deficiency, decreased insulin effectiveness or both. The report from the ministry of health shows that DMs prevalence data of East Java province is 2.1%, while the DMs prevalence of Indonesia is only 1,5%. Given the high cases of DM in East Java, it needs the preventive action to control factors causing the complication of DM. This study aims to determine the combination factors causing the complication of DM to reduce the bias by confounding variables using Propensity Score Matching (PSM) with the method of propensity score estimation is binary logistic regression. The data used in this study is the medical record from As-Shafa clinic consisting of 6 covariates and health complication as response variable. The result of PSM analysis showed that there are 22 of 126 DMs patients attending gymnastics paired with patients who didnt attend to diabetes gymnastics. The Average Treatment of Treated (ATT) estimation results showed that the more patients who didnt attend to gymnastics, the more likely the risk for the patients having DMs complications.

Non-calcified coronary plaque volume inversely related to CD4 count in HIV infection

PubMed Central

Duarte, Horacio; Matta, Jatin R.; Muldoon, Nancy; Masur, Henry; Hadigan, Colleen; Gharib, Ahmed M.

2013-01-01

Background Non-calcified coronary artery plaque (NCAP) may be an important predictor of cardiovascular events, however, few studies have directly measured NCAP in HIV-infected individuals. Methods We completed a prospective cross-sectional evaluation of NCAP and coronary calcium scores using CT angiography in HIV-infected subjects (n=26) without known coronary artery disease (CAD), but who had one or more CAD risk factor and compared them to controls matched on age, race, sex, body mass index and Framingham risk score (n=26). Results There was no difference in coronary calcium scores (114 ± 218 vs. 124 ± 298 p=0.89) or NCAP volume (65 ± 86 mm3 vs. 63 ± 82 mm3, p=0.38) between HIV-infected subjects and controls, respectively. Among HIV-infected subjects, lower CD4 count was associated with increased NCAP volume (r=-0.52, p=0.006). CD4 count remained a significant predictor of NCAP in a multivariate analysis that adjusted for age and duration of antiretroviral therapy. Conclusion Plaque burden is similar between HIV-infected and uninfected individuals when matched on traditional CAD risk factors, however immune function may mediate the development of atherosclerosis in HIV infection. PMID:22293714

Effects of a Self-Exercise Program on Activities of Daily Living in Patients After Acute Stroke: A Propensity Score Analysis Based on the Japan Association of Rehabilitation Database.

PubMed

Shiraishi, Nariaki; Suzuki, Yusuke; Matsumoto, Daisuke; Jeong, Seungwon; Sugiyama, Motoya; Kondo, Katsunori

2017-03-01

To investigate whether self-exercise programs for patients after stroke contribute to improved activities of daily living (ADL) at hospital discharge. Retrospective, observational, propensity score (PS)-matched case-control study. General hospitals. Participants included patients after stroke (N=1560) hospitalized between January 3, 2006, and December 26, 2012, satisfying the following criteria: (1) data on age, sex, duration from stroke to hospital admission, length of stay, FIM score, modified Rankin Scale (mRS) score, Glasgow Coma Scale score, Japan Stroke Scale score, and self-exercise program participation were available; and (2) admitted within 7 days after stroke onset, length of stay was between 7 and 60 days, prestroke mRS score was ≤2, and not discharged because of FIM or mRS exacerbation. A total of 780 PS-matched pairs were selected for each of the self-exercise program and no-self-exercise program groups. Self-exercise program participation. At discharge, FIM motor score, FIM cognitive score, FIM motor score gain (discharge value - admission value), FIM motor score gain rate (gain/length of stay), a binary variable divided by the median FIM motor score gain rate (high efficiency or no-high efficiency), and mRS score. Patients were classified into a self-exercise program (n=780) or a no-self-exercise program (n=780) group. After matching, there were no significant between-group differences, except motor system variables. The receiver operating characteristic curve for PS had an area under the curve value of .71 with a 95% confidence interval of .68 to .73, and the model was believed to have a relatively favorable fit. A logistic regression analysis of PS-matched pairs suggested that the self-exercise program was effective, with an overall odds ratio for ADL (high efficiency or no-high efficiency) of 2.2 (95% confidence ratio, 1.75-2.70). SEPs may contribute to improving ADL. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Word Detection in Sung and Spoken Sentences in Children With Typical Language Development or With Specific Language Impairment

PubMed Central

Planchou, Clément; Clément, Sylvain; Béland, Renée; Cason, Nia; Motte, Jacques; Samson, Séverine

2015-01-01

Background: Previous studies have reported that children score better in language tasks using sung rather than spoken stimuli. We examined word detection ease in sung and spoken sentences that were equated for phoneme duration and pitch variations in children aged 7 to 12 years with typical language development (TLD) as well as in children with specific language impairment (SLI ), and hypothesized that the facilitation effect would vary with language abilities. Method: In Experiment 1, 69 children with TLD (7–10 years old) detected words in sentences that were spoken, sung on pitches extracted from speech, and sung on original scores. In Experiment 2, we added a natural speech rate condition and tested 68 children with TLD (7–12 years old). In Experiment 3, 16 children with SLI and 16 age-matched children with TLD were tested in all four conditions. Results: In both TLD groups, older children scored better than the younger ones. The matched TLD group scored higher than the SLI group who scored at the level of the younger children with TLD . None of the experiments showed a facilitation effect of sung over spoken stimuli. Conclusions: Word detection abilities improved with age in both TLD and SLI groups. Our findings are compatible with the hypothesis of delayed language abilities in children with SLI , and are discussed in light of the role of durational prosodic cues in words detection. PMID:26767070

Statin use and kidney cancer outcomes: A propensity score analysis.

PubMed

Nayan, Madhur; Finelli, Antonio; Jewett, Michael A S; Juurlink, David N; Austin, Peter C; Kulkarni, Girish S; Hamilton, Robert J

2016-11-01

Studies evaluating the association between statin use and survival outcomes in renal cell carcinoma have demonstrated conflicting results. Our objective was to evaluate this association in a large clinical cohort by using propensity score methods to reduce confounding from measured covariates. We performed a retrospective review of 893 patients undergoing nephrectomy for unilateral, M0 renal cell carcinoma between 2000 and 2014 at a tertiary academic center. Inverse probability of treatment weights were derived from a propensity score model based on clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between statin use and disease-free survival, cancer-specific survival, and overall survival in the sample weighted by the inverse probability of treatment weights. A secondary analysis was performed matching statin users 1:1 to statin nonusers on the propensity score. Of the 893 patients, 259 (29%) were on statins at the time of surgery. Median follow-up was 47 months (interquartile range: 20-80). Statin use was not significantly associated with disease-free survival (hazard ratio [HR] = 1.09, 95% CI: 0.65-1.81), cancer-specific survival (HR = 0.90, 95% CI: 0.40-2.01), or overall survival (HR = 0.89, 95% CI: 0.55-1.44). Similar results were observed when using propensity score matching. The present study found no significant association between statin use and kidney cancer outcomes. Population-based studies are needed to further evaluate the role of statins in kidney cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Psychosocial Concerns in the Medical Encounter: A Comparison of the Interactions of Doctors with Their Old and Young Patients.

ERIC Educational Resources Information Center

Greene, Michele G.; And Others

1987-01-01

Using a newly developed coding method, the Geriatric Interaction Analysis system, the interactions of doctors with a matched sample of older and younger patients were audiotaped and scored. Patients and doctors raised fewer psychosocial issues in interviews with older patients than with younger patients. Doctors also responded less well to these…

Holding Abusers Accountable: An Elder Abuse Forensic Center Increases Criminal Prosecution of Financial Exploitation

ERIC Educational Resources Information Center

Navarro, Adria E.; Gassoumis, Zachary D.; Wilber, Kathleen H.

2013-01-01

Purpose: Despite growing awareness of elder abuse, cases are rarely prosecuted. The aim of this study was to examine the effectiveness of an elder abuse forensic center compared with usual care to increase prosecution of elder financial abuse. Design and Methods: Using one-to-one propensity score matching, cases referred to the Los Angeles County…

Combining Group-Based Trajectory Modeling and Propensity Score Matching for Causal Inferences in Nonexperimental Longitudinal Data

ERIC Educational Resources Information Center

Haviland, Amelia; Nagin, Daniel S.; Rosenbaum, Paul R.; Tremblay, Richard E.

2008-01-01

A central theme of research on human development and psychopathology is whether a therapeutic intervention or a turning-point event, such as a family break-up, alters the trajectory of the behavior under study. This article describes and applies a method for using observational longitudinal data to make more transparent causal inferences about the…

Fall-Related Hospitalization and Facility Costs among Residents of Institutions Providing Long-Term Care

ERIC Educational Resources Information Center

Carroll, Norman V.; Delafuente, Jeffrey C.; Cox, Fred M.; Narayanan, Siva

2008-01-01

Purpose: The purpose of this study was to estimate hospital and long-term-care costs resulting from falls in long-term-care facilities (LTCFs). Design and Methods: The study used a retrospective, pre/post with comparison group design. We used matching, based on propensity scores, to control for baseline differences between fallers and non-fallers.…

Using Propensity Score Matching Methods to Improve Generalization from Randomized Experiments

ERIC Educational Resources Information Center

Tipton, Elizabeth

2011-01-01

The main result of an experiment is typically an estimate of the average treatment effect (ATE) and its standard error. In most experiments, the number of covariates that may be moderators is large. One way this issue is typically skirted is by interpreting the ATE as the average effect for "some" population. Cornfield and Tukey (1956)…

PF2fit: Polar Fast Fourier Matched Alignment of Atomistic Structures with 3D Electron Microscopy Maps.

PubMed

Bettadapura, Radhakrishna; Rasheed, Muhibur; Vollrath, Antje; Bajaj, Chandrajit

2015-10-01

There continue to be increasing occurrences of both atomistic structure models in the PDB (possibly reconstructed from X-ray diffraction or NMR data), and 3D reconstructed cryo-electron microscopy (3D EM) maps (albeit at coarser resolution) of the same or homologous molecule or molecular assembly, deposited in the EMDB. To obtain the best possible structural model of the molecule at the best achievable resolution, and without any missing gaps, one typically aligns (match and fits) the atomistic structure model with the 3D EM map. We discuss a new algorithm and generalized framework, named PF(2) fit (Polar Fast Fourier Fitting) for the best possible structural alignment of atomistic structures with 3D EM. While PF(2) fit enables only a rigid, six dimensional (6D) alignment method, it augments prior work on 6D X-ray structure and 3D EM alignment in multiple ways: Scoring. PF(2) fit includes a new scoring scheme that, in addition to rewarding overlaps between the volumes occupied by the atomistic structure and 3D EM map, rewards overlaps between the volumes complementary to them. We quantitatively demonstrate how this new complementary scoring scheme improves upon existing approaches. PF(2) fit also includes two scoring functions, the non-uniform exterior penalty and the skeleton-secondary structure score, and implements the scattering potential score as an alternative to traditional Gaussian blurring. Search. PF(2) fit utilizes a fast polar Fourier search scheme, whose main advantage is the ability to search over uniformly and adaptively sampled subsets of the space of rigid-body motions. PF(2) fit also implements a new reranking search and scoring methodology that considerably improves alignment metrics in results obtained from the initial search.

Soccer Injury Movement Screen (SIMS) Composite Score Is Not Associated With Injury Among Semi-Professional Soccer Players.

PubMed

McCunn, Robert; Fünten, Karen Aus der; Whalan, Matthew; Sampson, John A; Meyer, Tim

2018-05-08

Study Design Prospective cohort. Background The association between movement quality and injury is equivocal. No soccer-specific movement assessment has been prospectively investigated in relation to injury risk. Objectives To investigate the association between a soccer-specific movement quality assessment and injury risk among semi-professional soccer players. Methods Semi-professional soccer players (n=306) from 12 clubs completed the Soccer Injury Movement Screen (SIMS) during the pre-season period. Individual training/match exposure and non-contact time loss injuries were recorded prospectively for the entirety of the 2016 season. Relative risks (RR) were calculated, and presented with 90% confidence intervals (CI), for the SIMS composite and individual sub-test scores from generalized linear models with Poisson distribution offset for exposure. Results When considering non-contact time loss lower extremity injuries (primary level of analysis), there was a most likely trivial association with the SIMS composite score. Similarly, SIMS composite score demonstrated most likely to likely trivial associations to all injury categories included in the secondary level of analysis (non-contact time loss hip/groin, thigh, knee and ankle injuries). When considering hamstring strains and ankle sprains specifically (tertiary level of analysis) the SIMS composite score, again, demonstrated very likely trivial associations. A total of 262 non-contact time loss injuries were recorded. The overall (training and match exposure combined) incidence of non-contact time loss injury was 12/1000 hours. Conclusion The SIMS composite score demonstrated no association to any of the investigated categories of soccer-related injury. The SIMS composite score should not be used to group players into 'high' or 'low' risk groups. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther, Epub 8 May 2018. doi:10.2519/jospt.2018.8037.

PF2 fit: Polar Fast Fourier Matched Alignment of Atomistic Structures with 3D Electron Microscopy Maps

PubMed Central

Bettadapura, Radhakrishna; Rasheed, Muhibur; Vollrath, Antje; Bajaj, Chandrajit

2015-01-01

There continue to be increasing occurrences of both atomistic structure models in the PDB (possibly reconstructed from X-ray diffraction or NMR data), and 3D reconstructed cryo-electron microscopy (3D EM) maps (albeit at coarser resolution) of the same or homologous molecule or molecular assembly, deposited in the EMDB. To obtain the best possible structural model of the molecule at the best achievable resolution, and without any missing gaps, one typically aligns (match and fits) the atomistic structure model with the 3D EM map. We discuss a new algorithm and generalized framework, named PF2 fit (Polar Fast Fourier Fitting) for the best possible structural alignment of atomistic structures with 3D EM. While PF2 fit enables only a rigid, six dimensional (6D) alignment method, it augments prior work on 6D X-ray structure and 3D EM alignment in multiple ways: Scoring. PF2 fit includes a new scoring scheme that, in addition to rewarding overlaps between the volumes occupied by the atomistic structure and 3D EM map, rewards overlaps between the volumes complementary to them. We quantitatively demonstrate how this new complementary scoring scheme improves upon existing approaches. PF2 fit also includes two scoring functions, the non-uniform exterior penalty and the skeleton-secondary structure score, and implements the scattering potential score as an alternative to traditional Gaussian blurring. Search. PF2 fit utilizes a fast polar Fourier search scheme, whose main advantage is the ability to search over uniformly and adaptively sampled subsets of the space of rigid-body motions. PF2 fit also implements a new reranking search and scoring methodology that considerably improves alignment metrics in results obtained from the initial search. PMID:26469938

Evaluation of accuracy of shade selection using two spectrophotometer systems: Vita Easyshade and Degudent Shadepilot

PubMed Central

Kalantari, Mohammad Hassan; Ghoraishian, Seyed Ahmad; Mohaghegh, Mina

2017-01-01

Objective: The aim of this in vitro study was to evaluate the accuracy of shade matching using two spectrophotometric devices. Materials and Methods: Thirteen patients who require a full coverage restoration for one of their maxillary central incisors were selected while the adjacent central incisor was intact. 3 same frameworks were constructed for each tooth using computer-aided design and computer-aided manufacturing technology. Shade matching was performed using Vita Easyshade spectrophotometer, Shadepilot spectrophotometer, and Vitapan classical shade guide for the first, second, and third crown subsequently. After application, firing, and glazing of the porcelain, the color was evaluated and scored by five inspectors. Results: Both spectrophotometric systems showed significantly better results than visual method (P < 0.05) while there were no significant differences between Vita Easyshade and Shadepilot spectrophotometers (P < 0.05). Conclusion: Spectrophotometers are a good substitute for visual color selection methods. PMID:28729792

An approach to automated particle picking from electron micrographs based on reduced representation templates.

PubMed

Volkmann, Niels

2004-01-01

Reduced representation templates are used in a real-space pattern matching framework to facilitate automatic particle picking from electron micrographs. The procedure consists of five parts. First, reduced templates are constructed either from models or directly from the data. Second, a real-space pattern matching algorithm is applied using the reduced representations as templates. Third, peaks are selected from the resulting score map using peak-shape characteristics. Fourth, the surviving peaks are tested for distance constraints. Fifth, a correlation-based outlier screening is applied. Test applications to a data set of keyhole limpet hemocyanin particles indicate that the method is robust and reliable.

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis.

PubMed

Ahrar, Judy U; Gupta, Sanjay; Ensor, Joe E; Mahvash, Armeen; Sabir, Sharjeel H; Steele, Joseph R; McRae, Stephen E; Avritscher, Rony; Huang, Steven Y; Odisio, Bruno C; Murthy, Ravi; Ahrar, Kamran; Wallace, Michael J; Tam, Alda L

2017-02-01

To evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy. In this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if the absolute difference in their propensity scores was ≤equal to 0.02. Before matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates. The self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.

Sensors vs. experts - A performance comparison of sensor-based fall risk assessment vs. conventional assessment in a sample of geriatric patients

PubMed Central

2011-01-01

Background Fall events contribute significantly to mortality, morbidity and costs in our ageing population. In order to identify persons at risk and to target preventive measures, many scores and assessment tools have been developed. These often require expertise and are costly to implement. Recent research investigates the use of wearable inertial sensors to provide objective data on motion features which can be used to assess individual fall risk automatically. So far it is unknown how well this new method performs in comparison with conventional fall risk assessment tools. The aim of our research is to compare the predictive performance of our new sensor-based method with conventional and established methods, based on prospective data. Methods In a first study phase, 119 inpatients of a geriatric clinic took part in motion measurements using a wireless triaxial accelerometer during a Timed Up&Go (TUG) test and a 20 m walk. Furthermore, the St. Thomas Risk Assessment Tool in Falling Elderly Inpatients (STRATIFY) was performed, and the multidisciplinary geriatric care team estimated the patients' fall risk. In a second follow-up phase of the study, 46 of the participants were interviewed after one year, including a fall and activity assessment. The predictive performances of the TUG, the STRATIFY and team scores are compared. Furthermore, two automatically induced logistic regression models based on conventional clinical and assessment data (CONV) as well as sensor data (SENSOR) are matched. Results Among the risk assessment scores, the geriatric team score (sensitivity 56%, specificity 80%) outperforms STRATIFY and TUG. The induced logistic regression models CONV and SENSOR achieve similar performance values (sensitivity 68%/58%, specificity 74%/78%, AUC 0.74/0.72, +LR 2.64/2.61). Both models are able to identify more persons at risk than the simple scores. Conclusions Sensor-based objective measurements of motion parameters in geriatric patients can be used to assess individual fall risk, and our prediction model's performance matches that of a model based on conventional clinical and assessment data. Sensor-based measurements using a small wearable device may contribute significant information to conventional methods and are feasible in an unsupervised setting. More prospective research is needed to assess the cost-benefit relation of our approach. PMID:21711504

Neyman-Pearson biometric score fusion as an extension of the sum rule

NASA Astrophysics Data System (ADS)

Hube, Jens Peter

2007-04-01

We define the biometric performance invariance under strictly monotonic functions on match scores as normalization symmetry. We use this symmetry to clarify the essential difference between the standard score-level fusion approaches of sum rule and Neyman-Pearson. We then express Neyman-Pearson fusion assuming match scores defined using false acceptance rates on a logarithmic scale. We show that by stating Neyman-Pearson in this form, it reduces to sum rule fusion for ROC curves with logarithmic slope. We also introduce a one parameter model of biometric performance and use it to express Neyman-Pearson fusion as a weighted sum rule.

Assessing the Impact of School-Based Health Centers on Academic Achievement and College Preparation Efforts: Using Propensity Score Matching to Assess School-Level Data in California.

PubMed

Bersamin, Melina; Garbers, Samantha; Gaarde, Jenna; Santelli, John

2016-08-01

This study examines the association between school-based health center (SBHC) presence and school-wide measures of academic achievement and college preparation efforts. Publicly available educational and demographic data from 810 California public high schools were linked to a list of schools with an SBHC. Propensity score matching, a method to reduce bias inherent in nonrandomized control studies, was used to select comparison schools. Regression analyses, controlling for proportion of English-language learners, were conducted for each outcome including proportion of students participating in three College Board exams, graduation rates, and meeting university graduation requirements. Findings suggest that SBHC presence is positively associated with college preparation outcomes but not with academic achievement outcomes (graduation rates or meeting state graduation requirements). Future research must examine underlying mechanisms supporting this association, such as school connectedness. Additional research should explore the role that SBHC staff could have in supporting college preparation efforts. © The Author(s) 2016.

Complementary health insurance, out- of- pocket expenditures, and health services utilization: A population- based survey.

PubMed

Homaie Rad, Enayatollah; Kavosi, Zahra; Moghadamnia, Mohammad Taghi; Arefnezhad, Masoud; Arefnezhad, Masoumeh; Felezi Nasiri, Banfashe

2017-01-01

Background: Studies have shown that people using complementary health insurances have more access to health services than others. In the present study, we aimed at finding the differences between out- of- pocket payments and health service utilizations in complementary health insurances (CHIs) users and nonusers. Methods: Propensity score matching was used to compare the 2 groups. First, confounder variables were identified, and then propensity score matching was used to compare out- of- pocket expenditures with dental, general physician, hospital inpatient, emergency services, nursing, midwifery, laboratory services, specialists and rehabilitation services utilization. Results: Our results revealed no significant differences between the 2 groups in out- of- pocket health expenditures. Also, the specialist visits, inpatient services at the hospital, and dental services were higher in people who used CHIs compared to nonusers. Conclusion: People did not change their budget share for health care services after using CHIs. The payments were equal for people who were not CHIs users due to the increase in the quantity of the services.

Propensity Score Matching Helps to Understand Sources of DIF and Mathematics Performance Differences of Indonesian, Turkish, Australian, and Dutch Students in PISA

ERIC Educational Resources Information Center

Arikan, Serkan; van de Vijver, Fons J. R.; Yagmur, Kutlay

2018-01-01

We examined Differential Item Functioning (DIF) and the size of cross-cultural performance differences in the Programme for International Student Assessment (PISA) 2012 mathematics data before and after application of propensity score matching. The mathematics performance of Indonesian, Turkish, Australian, and Dutch students on released items was…

Predictors of matching in an ophthalmology residency program.

PubMed

Loh, Allison R; Joseph, Damien; Keenan, Jeremy D; Lietman, Thomas M; Naseri, Ayman

2013-04-01

To examine the characteristics of US medical students applying for ophthalmology residency and to determine the predictors of matching. A retrospective case series. A total of 3435 medical students from the United States who applied to an ophthalmology residency program from 2003 to 2008 were included. Matched and unmatched applicants were compared and stratified by predictor variables, including United States Medical Licensing Examination (USMLE) Step 1 score, Alpha Omega Alpha (AOA) status, medical school reputation, and medical school geographic region. Differences in proportions were analyzed using the Fisher exact test. Logistic regression was used to determine the predictors of successful matching. Successful matching to an ophthalmology program. The majority of applicants (72%, 2486/3435) matched in ophthalmology. In multivariate analysis, AOA membership (odds ratio [OR], 2.6, P<0.0001), USMLE score (OR, 1.6; P<0.0001), presence of an ophthalmology residency at medical school (OR, 1.4; P = 0.01), top 25 medical school (OR, 1.4; P<0.03), top 10 medical school (OR, 1.6; P<0.02), and allopathic degree (OR, 4.0; P<0.0001) were statistically significant predictors of matching. Approximately 60% (1442/2486) of applicants matched to the same geographic region as their medical school. Applicants were more likely to match at a program in the same geographic region as their medical school than would be predicted by chance alone (P<0.0001). In multivariate analysis, higher USMLE score (OR, 0.9; P<0.0001) and top 10 medical school (OR, 0.7; P = 0.027) were statistically significant predictors of matching to outside the geographic region as one's medical school. The majority of applicants applying for an ophthalmology residency position match successfully. Higher performance on quantitative metrics seems to confer an advantage for matching. The majority of applicants match at a residency program within the same geographic region as one's medical school. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The Association between the Availability of Sugar-Sweetened Beverage in School Vending Machines and Its Consumption among Adolescents in California: A Propensity Score Matching Approach

PubMed Central

Shi, Lu

2010-01-01

There is controversy over to what degree banning sugar-sweetened beverage (SSB) sales at schools could decrease the SSB intake. This paper uses the adolescent sample of 2005 California Health Interview Survey to estimate the association between the availability of SSB from school vending machines and the amount of SSB consumption. Propensity score stratification and kernel-based propensity score matching are used to address the selection bias issue in cross-sectional data. Propensity score stratification shows that adolescents who had access to SSB through their school vending machines consumed 0.170 more drinks of SSB than those who did not (P < .05). Kernel-based propensity score matching shows the SSB consumption difference to be 0.158 on the prior day (P < .05). This paper strengthens the evidence for the association between SSB availability via school vending machines and the actual SSB consumption, while future studies are needed to explore changes in other beverages after SSB becomes less available. PMID:20976298

The Possible Antecedents and Consequences of Matching of Food Intake: Examining the Role of Trait Self-Esteem and Interpersonal Closeness.

PubMed

Hirata, Elizabeth; Lodder, Gerine M A; Kühnen, Ulrich; Lippke, Sonia; Hermans, Roel C J

2015-01-01

Although there is evidence that people tend to match their intake to that of others, less is known about the motives underlying this effect. The current study, therefore, examined the relationship between self-esteem, a specific factor that has been related to the likelihood of social matching. Further, we examined the effects of food matching on interpersonal closeness among eating companions. The sample included 89 female dyads. All dyads had free access to palatable snack food during a 15 min interaction. For each dyad the matching score was calculated, as well as both individual's trait self-esteem scores and interpersonal closeness with their eating partner. The overall degree of matching within dyads was high, replicating the findings of previous research. No relationship, however, was found between trait self-esteem and the degree of matching. Furthermore, there was no effect of matching on perceived interpersonal closeness with or liking of the other person. These results suggest that self-esteem might not be a robust predictor of matching and that matching of food intake may not result in increased perceived interpersonal closeness or liking among eating partners.

The Possible Antecedents and Consequences of Matching of Food Intake: Examining the Role of Trait Self-Esteem and Interpersonal Closeness

PubMed Central

Hirata, Elizabeth; Lodder, Gerine M. A.; Kühnen, Ulrich; Lippke, Sonia; Hermans, Roel C. J.

2015-01-01

Although there is evidence that people tend to match their intake to that of others, less is known about the motives underlying this effect. The current study, therefore, examined the relationship between self-esteem, a specific factor that has been related to the likelihood of social matching. Further, we examined the effects of food matching on interpersonal closeness among eating companions. The sample included 89 female dyads. All dyads had free access to palatable snack food during a 15 min interaction. For each dyad the matching score was calculated, as well as both individual's trait self-esteem scores and interpersonal closeness with their eating partner. The overall degree of matching within dyads was high, replicating the findings of previous research. No relationship, however, was found between trait self-esteem and the degree of matching. Furthermore, there was no effect of matching on perceived interpersonal closeness with or liking of the other person. These results suggest that self-esteem might not be a robust predictor of matching and that matching of food intake may not result in increased perceived interpersonal closeness or liking among eating partners. PMID:26733911

Electronic Residency Application Service Application Characteristics Associated with Successful Residency Matching in Neurosurgery in 2009-2016.

PubMed

Leschke, John M; Hunt, Matthew A

2018-05-01

Resident applicants in neurosurgery often wonder what factors impact their chances of successfully matching. Using data published by the National Residency Match Program for 2009-2016, we examined which components of the Electronic Residency Application Service application correlated with successful residency matching. Data were collected from the National Residency Match Program publication Charting Outcomes in the Match from all years it was available for neurosurgery (2009, 2011, 2014, 2016). Individual factors reported (number of contiguous ranks, research projects, publications and presentations, work experiences, volunteer experiences, United States Medical Licensing Examination Step 1 and 2 score deciles, categorical data about Alpha Omega Alpha status, Ph.D. degree, other degree, and strength of medical school National Institutes of Health funding) were aggregated for all 3 years. Categorical data were available only for U.S. seniors. Spearman correlation and χ 2 were used for ranked data and categorical data, respectively. Separate analyses were run for U.S. seniors and independent applicants. For U.S. seniors applying to neurosurgery, number of contiguous ranks, United States Medical Licensing Examination Step 1 and 2 scores, research projects, Alpha Omega Alpha status, and medical school top 40 National Institutes of Health funding were significantly associated with successful matching of applicants. Number of volunteer experiences was nearly statistically significant. For independent applicants, only United States Medical Licensing Examination Step 1 and 2 scores and number of research projects were statistically significant. This is the first study to analyze National Residency Match Program data for predictors of success in neurosurgical matching. Students applying to neurosurgery residency and their mentors should be aware of which baseline objective factors are associated with match success. Copyright © 2018 Elsevier Inc. All rights reserved.

Impact of an entertainment-education television drama on health knowledge and behavior in Bangladesh: an application of propensity score matching.

PubMed

Do, Mai P; Kincaid, D Lawrence

2006-01-01

Shabuj Chaya is a weekly television drama broadcast during a 13-week period in Bangladesh in 2000. It used an entertainment-education format to increase health knowledge and to promote visits to health clinic and modern contraceptive use. The purpose of this article is to demonstrate how a relatively new statistical technique, propensity score matching in conjunction with structural equation modeling, can be used to obtain an unbiased estimate of changes in health outcomes that can be attributed to exposure to the drama. The analysis is conducted with data from an after-only, cross-sectional survey of 4,492 men and women from the intended audience. The results from propensity score matching approximate what would be expected from a randomized control group design.

Anesthesia Technique and Mortality after Total Hip or Knee Arthroplasty: A Retrospective, Propensity Score-matched Cohort Study.

PubMed

Perlas, Anahi; Chan, Vincent W S; Beattie, Scott

2016-10-01

This propensity score-matched cohort study evaluates the effect of anesthetic technique on a 30-day mortality after total hip or knee arthroplasty. All patients who had hip or knee arthroplasty between January 1, 2003, and December 31, 2014, were evaluated. The principal exposure was spinal versus general anesthesia. The primary outcome was 30-day mortality. Secondary outcomes were (1) perioperative myocardial infarction; (2) a composite of major adverse cardiac events that includes cardiac arrest, myocardial infarction, or newly diagnosed arrhythmia; (3) pulmonary embolism; (4) major blood loss; (5) hospital length of stay; and (6) operating room procedure time. A propensity score-matched-pair analysis was performed using a nonparsimonious logistic regression model of regional anesthetic use. We identified 10,868 patients, of whom 8,553 had spinal anesthesia and 2,315 had general anesthesia. Ninety-two percent (n = 2,135) of the patients who had general anesthesia were matched to similar patients who did not have general anesthesia. In the matched cohort, the 30-day mortality rate was 0.19% (n = 4) in the spinal anesthesia group and 0.8% (n = 17) in the general anesthesia group (risk ratio, 0.42; 95% CI, 0.21 to 0.83; P = 0.0045). Spinal anesthesia was also associated with a shorter hospital length of stay (5.7 vs. 6.6 days; P < 0.001). The results of this observational, propensity score-matched cohort study suggest a strong association between spinal anesthesia and lower 30-day mortality, as well as a shorter hospital length of stay, after elective joint replacement surgery.

Evaluating the effect of spatial subsetting on subpixel unmixing methodology applied to ASTER over a hydrothermally altered terrain

NASA Astrophysics Data System (ADS)

Ayoobi, Iman; Tangestani, Majid H.

2017-10-01

This study investigates the effect of spatial subsets of Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) L1B visible-near infrared and short wave-infrared (VNIR-SWIR) data on matched filtering results at the central part of Kerman magmatic arc, where abundant porphyry copper deposits exist. The matched filtering (MF) procedure was run separately at sites containing hydrothermal minerals such as sericite, kaolinite, chlorite, and jarosite to map the abundances of these minerals on spatial subsets containing 100, 75, 50, and 25 percent of the original scene. Results were evaluated by comparing the matched filtering scores with the mineral abundances obtained by semi-quantitative XRD analysis of corresponding field samples. It was concluded that MF method should be applied to the whole scene prior to any data subsetting.

Instructional methods and cognitive and learning styles in web-based learning: report of two randomised trials.

PubMed

Cook, David A; Gelula, Mark H; Dupras, Denise M; Schwartz, Alan

2007-09-01

Adapting web-based (WB) instruction to learners' individual differences may enhance learning. Objectives This study aimed to investigate aptitude-treatment interactions between learning and cognitive styles and WB instructional methods. We carried out a factorial, randomised, controlled, crossover, post-test-only trial involving 89 internal medicine residents, family practice residents and medical students at 2 US medical schools. Parallel versions of a WB course in complementary medicine used either active or reflective questions and different end-of-module review activities ('create and study a summary table' or 'study an instructor-created table'). Participants were matched or mismatched to question type based on active or reflective learning style. Participants used each review activity for 1 course module (crossover design). Outcome measurements included the Index of Learning Styles, the Cognitive Styles Analysis test, knowledge post-test, course rating and preference. Post-test scores were similar for matched (mean +/- standard error of the mean 77.4 +/- 1.7) and mismatched (76.9 +/- 1.7) learners (95% confidence interval [CI] for difference - 4.3 to 5.2l, P = 0.84), as were course ratings (P = 0.16). Post-test scores did not differ between active-type questions (77.1 +/- 2.1) and reflective-type questions (77.2 +/- 1.4; P = 0.97). Post-test scores correlated with course ratings (r = 0.45). There was no difference in post-test subscores for modules completed using the 'construct table' format (78.1 +/- 1.4) or the 'table provided' format (76.1 +/- 1.4; CI - 1.1 to 5.0, P = 0.21), and wholist and analytic styles had no interaction (P = 0.75) or main effect (P = 0.18). There was no association between activity preference and wholist or analytic scores (P = 0.37). Cognitive and learning styles had no apparent influence on learning outcomes. There were no differences in outcome between these instructional methods.

Propensity Score Analysis of Radical Cystectomy Versus Bladder-Sparing Trimodal Therapy in the Setting of a Multidisciplinary Bladder Cancer Clinic.

PubMed

Kulkarni, Girish S; Hermanns, Thomas; Wei, Yanliang; Bhindi, Bimal; Satkunasivam, Raj; Athanasopoulos, Paul; Bostrom, Peter J; Kuk, Cynthia; Li, Kathy; Templeton, Arnoud J; Sridhar, Srikala S; van der Kwast, Theodorus H; Chung, Peter; Bristow, Robert G; Milosevic, Michael; Warde, Padraig; Fleshner, Neil E; Jewett, Michael A S; Bashir, Shaheena; Zlotta, Alexandre R

2017-07-10

Purpose Multidisciplinary management improves complex treatment decision making in cancer care, but its impact for bladder cancer (BC) has not been documented. Although radical cystectomy (RC) currently is viewed as the standard of care for muscle-invasive bladder cancer (MIBC), radiotherapy-based, bladder-sparing trimodal therapy (TMT) that combines transurethral resection of bladder tumor, chemotherapy for radiation sensitization, and external beam radiotherapy has emerged as a valid treatment option. In the absence of randomized studies, this study compared the oncologic outcomes between patients treated with RC or TMT by using a propensity score matched-cohort analysis. Methods Data from patients treated in a multidisciplinary bladder cancer clinic (MDBCC) from 2008 to 2013 were reviewed retrospectively. Those who received TMT for MIBC were identified and matched (for sex, cT and cN stage, Eastern Cooperative Oncology Group status, Charlson comorbidity score, treatment date, age, carcinoma in situ status, and hydronephrosis) with propensity scores to patients who underwent RC. Overall survival and disease-specific survival (DSS) were assessed with Cox proportional hazards modeling and a competing risk analysis, respectively. Results A total of 112 patients with MIBC were included after matching (56 who had been treated with TMT, and 56 who underwent RC). The median age was 68.0 years, and 29.5% had stage cT3/cT4 disease. At a median follow-up of 4.51 years, there were 20 deaths (35.7%) in the RC group (13 as a result of BC) and 22 deaths (39.3%) in the TMT group (13 as a result of BC). The 5-year DSS rate was 73.2% and 76.6% in the RC and TMT groups, respectively ( P = .49). Salvage cystectomy was performed in 6 (10.7%) of 56 patients who received TMT. Conclusion In the setting of a MDBCC, TMT yielded survival outcomes similar to those of matched patients who underwent RC. Appropriately selected patients with MIBC should be offered the opportunity to discuss various treatment options, including organ-sparing TMT.

Humanistic and economic burden of fibromyalgia in Japan

PubMed Central

Lee, Lulu K; Ebata, Nozomi; Hlavacek, Patrick; DiBonaventura, Marco; Cappelleri, Joseph C; Sadosky, Alesia

2016-01-01

Purpose The aim of this study was to examine the health and economic burden associated with fibromyalgia among adults in Japan. Materials and methods Data from the 2011–2014 Japan National Health and Wellness Survey (n=115,271), a nationally representative survey of adults, were analyzed. The greedy matching algorithm was used to match the respondents who self-reported a diagnosis of fibromyalgia with those not having fibromyalgia (n=256). Generalized linear models, controlling for covariates (eg, age and sex), examined whether the respondents with fibromyalgia differed from matched controls based on health status (health utilities; Mental and Physical Component Summary scores from Medical Outcomes Study: 12-item Version 2 and 36-item Version 2 Short Form Survey), sleep quality (ie, sleep difficulty symptoms), work productivity (Work Productivity and Activity Impairment Questionnaire – General Health Version 2.0), health care resource use, and estimated annual indirect and direct costs (based on published annual wages and resource use events) in Japanese yen (¥). Results After adjustment for covariates, respondents with fibromyalgia relative to matched controls scored significantly lower on health utilities (adjusted means =0.547 vs 0.732), Mental Component Summary score (33.15 vs 45.88), and Physical Component Summary score (39.22 vs 50.81), all with P<0.001; these differences exceeded the clinically meaningful levels. In addition, those with fibromyalgia reported significantly poorer sleep quality than those without fibromyalgia. Respondents with fibromyalgia compared with those without fibromyalgia experienced significantly more loss in work productivity and health care resource use, resulting in those with fibromyalgia incurring indirect costs that were more than twice as high (adjusted means =¥2,826,395 vs ¥1,201,547) and direct costs that were nearly six times as high (¥1,941,118 vs ¥335,140), both with P<0.001. Conclusion Japanese adults with fibromyalgia experienced significantly poorer health-related quality of life and greater loss in work productivity and health care use than those without fibromyalgia, resulting in significantly higher costs. Improving the rates of diagnosis and treatment for this chronic pain condition may be helpful in addressing this considerable humanistic and economic burden. PMID:27853390

Does the NBME Surgery Shelf exam constitute a "double jeopardy" of USMLE Step 1 performance?

PubMed

Ryan, Michael S; Colbert-Getz, Jorie M; Glenn, Salem N; Browning, Joel D; Anand, Rahul J

2017-02-01

Scores from the NBME Subject Examination in Surgery (Surgery Shelf) positively correlate with United States Medical Licensing Examination Step 1 (Step 1). Based on this relationship, the authors evaluated the predictive value of Step 1 on the Surgery Shelf. Surgery Shelf standard scores were substituted for Step 1 standard scores for 395 students in 2012-2014 at one medical school. Linear regression was used to determine how well Step 1 scores predicted Surgery Shelf scores. Percent match between original (with Shelf) and modified (with Step 1) clerkship grades were computed. Step 1 scores significantly predicted Surgery Shelf scores, R 2  = 0.42, P < 0.001. For every point increase in Step 1, a Surgery Shelf score increased by 0.30 points. Seventy-seven percent of original grades matched the modified grades. Replacing Surgery Shelf scores with Step 1 scores did not have an effect on the majority of final clerkship grades. This observation raises concern over use of Surgery Shelf scores as a measure of knowledge obtained during the Surgery clerkship. Copyright © 2016 Elsevier Inc. All rights reserved.

Statins use and risk of new-onset diabetes in hypertensive patients: a population-based retrospective cohort study in Yinzhou district, Ningbo city, People's Republic of China.

PubMed

Li, Hailong; Lin, Hongbo; Zhao, Houyu; Xu, Yang; Cheng, Yinchu; Shen, Peng; Zhan, Siyan

2018-01-01

Reports have suggested that statin use is associated with an increased incidence of type 2 diabetes mellitus (T2DM). Guidelines suggested that statins should be prescribed in hypertensive patients for primary prevention. However, there were very few studies on the risk of T2DM associated with statin use among patients with hypertension in mainland People's Republic of China. To determine the association between statin use and new-onset diabetes mellitus among patients with hypertension in mainland People's Republic of China. We performed a retrospective cohort study of hypertensive patients using the Yinzhou regional health care database from January 1, 2010, to August 31, 2016. Patients aged 30-90 years old without T2DM were eligible for inclusion. We identified new statin initiators and nonusers by using prescription records of inpatients and outpatients. Multivariate Cox model and propensity score methods were used to adjust potential confounders, including age, sex, body mass index, comorbidities, lifestyle characteristics, and baseline antihypertensive drug use. The risk of incident T2DM among statin initiators compared to nonusers was estimated by the Cox proportional hazards model. Propensity scores for statin use were then developed using logistic regression, statin initiators were matched 1:1 with nonusers according to propensity scores with the nearest neighbor matching method within 0.2 caliper width, and Cox regression was again conducted. Among 67,993 patients (21,551 statin initiators; 46,442 nonusers), the unadjusted incidence rate of incident T2DM was higher in statin initiators than nonusers (25.68 versus 14.19 events/1,000 person-years; adjusted hazard ratio: 1.55; 95% confidence interval: 1.44-1.66). After propensity score 1:1 matching (19,818 statin initiators; 19,818 nonusers), baseline characteristics between 2 groups were balanced except that the nonusers group was 0.53 years older on average ( P <0.001). Then statin use was still associated with a significant increased risk for T2DM in the matched cohort (adjusted hazard ratio: 1.54; 95% confidence interval: 1.41-1.67). Subgroup analyses also demonstrated similar findings. Our study indicated an association between statin use and an increased risk of new-onset diabetes mellitus. It provides better understanding of statin and new-onset diabetes mellitus association among hypertensive patients in real-word setting. As an observational study, our findings were prone to unmeasured confounding and bias.

Exploration of a 'double-jeopardy' hypothesis within working memory profiles for children with specific language impairment.

PubMed

Briscoe, J; Rankin, P M

2009-01-01

Children with specific language impairment (SLI) often experience difficulties in the recall and repetition of verbal information. Archibald and Gathercole (2006) suggested that children with SLI are vulnerable across two separate components of a tripartite model of working memory (Baddeley and Hitch 1974). However, the hierarchical relationship between the 'slave' systems (temporary storage) and the central executive components places a particular challenge for interpreting working memory profiles within a tripartite model. This study aimed to examine whether a 'double-jeopardy' assumption is compatible with a hierarchical relationship between the phonological loop and central executive components of the working memory model in children with SLI. If a strong double-jeopardy assumption is valid for children with SLI, it was predicted that raw scores of working memory tests thought to tap phonological loop and central executive components of tripartite working memory would be lower than the scores of children matched for chronological age and those of children matched for language level, according to independent sources of constraint. In contrast, a hierarchical relationship would imply that a weakness in a slave component of working memory (the phonological loop) would also constrain performance on tests tapping a super-ordinate component (central executive). This locus of constraint would predict that scores of children with SLI on working memory tests that tap the central executive would be weaker relative to the scores of chronological age-matched controls only. Seven subtests of the Working Memory Test Battery for Children (Digit recall, Word recall, Non-word recall, Word matching, Listening recall, Backwards digit recall and Block recall; Pickering and Gathercole 2001) were administered to 14 children with SLI recruited via language resource bases and specialist schools, as well as two control groups matched on chronological age and vocabulary level, respectively. Mean group differences were ascertained by directly comparing raw scores on memory tests linked to different components of the tripartite model using a series of multivariate analyses. The majority of working memory scores of the SLI group were depressed relative to chronological age-matched controls, with the exception of spatial recall (block tapping) and word (order) matching tasks. Marked deficits in serial recall of words and digits were evident, with the SLI group scoring more poorly than the language-ability matched control group on these measures. Impairments of the SLI group on phonological loop tasks were robust, even when covariance with executive working memory scores was accounted for. There was no robust effect of group on complex working memory (central executive) tasks, despite a slight association between listening recall and phonological loop measures. A predominant feature of the working memory profile of SLI was a marked deficit on phonological loop tasks. Although scores on complex working memory tasks were also depressed, there was little evidence for a strong interpretation of double-jeopardy within working memory profiles for these children, rather these findings were consistent with an interpretation of a constraint on phonological loop for children with SLI that operated at all levels of a hierarchical tripartite model of working memory (Baddeley and Hitch 1974). These findings imply that low scores on complex working memory tasks alone do not unequivocally imply an independent deficit in central executive (domain-general) resources of working memory and should therefore be treated cautiously in a clinical context.

Prenatal Glucocorticoid Treatment and Later Mental Health in Children and Adolescents

PubMed Central

Khalife, Natasha; Glover, Vivette; Taanila, Anja; Ebeling, Hanna; Järvelin, Marjo-Riitta; Rodriguez, Alina

2013-01-01

Background Animal studies demonstrate a clear link between prenatal exposure to glucocorticoids (GC) and altered offspring brain development. We aim to examine whether prenatal GC exposure programs long-term mental health in humans. Methods Using propensity-score-matching, children prenatally exposed to synthetic glucocorticoids (sGC), n=37, and controls, n=185, were balanced on important confounders related to sGC treatment - gestational age and pre-pregnancy BMI. We also used mixed-effects modeling to analyse the entire cohort – matching each sGC case, n=37, to all possible controls, n=6079, on gestational age and sex. We obtained data from the Northern Finland Birth Cohort 1986 at four waves – pregnancy, birth, 8 and 16 years. Data on pregnancy and birth outcomes came from medical records. Mental health was assessed at 8 years by teachers with the Rutter B2 scale, and at 16 years by parents with the Strengths and Weaknesses of ADHD symptoms and Normal behavior (SWAN) scale and adolescents by the Youth Self-Report (YSR) scale. Results Prenatal sGC treatment was consistently associated with adverse mental health in childhood and adolescence, as shown by both the propensity-score method and mixed-effects model. Using the propensity-score-matched subsample, linear multiple regression showed prenatal sGC was significantly linked with general psychiatric disturbance (B=8.34 [95% CI: .23-16.45]) and inattention (B= .97 [95% CI: .16-1.80]) at 8 years after control for relevant confounders. Similar findings were obtained at 16 years, but did not reach statistical significance. Mediation by birthweight/placental weight was not detected. Conclusions This study is the first to prospectively investigate the long-term associations between prenatal exposure to sGC treatment and mental health in children and adolescents. We report an association between prenatal exposure to sGC and child mental health, supportive of the idea that sGC has a programming effect on the fetal brain. PMID:24278432

Evaluating statistical approaches to leverage large clinical datasets for uncovering therapeutic and adverse medication effects.

PubMed

Choi, Leena; Carroll, Robert J; Beck, Cole; Mosley, Jonathan D; Roden, Dan M; Denny, Joshua C; Van Driest, Sara L

2018-04-18

Phenome-wide association studies (PheWAS) have been used to discover many genotype-phenotype relationships and have the potential to identify therapeutic and adverse drug outcomes using longitudinal data within electronic health records (EHRs). However, the statistical methods for PheWAS applied to longitudinal EHR medication data have not been established. In this study, we developed methods to address two challenges faced with reuse of EHR for this purpose: confounding by indication, and low exposure and event rates. We used Monte Carlo simulation to assess propensity score (PS) methods, focusing on two of the most commonly used methods, PS matching and PS adjustment, to address confounding by indication. We also compared two logistic regression approaches (the default of Wald vs. Firth's penalized maximum likelihood, PML) to address complete separation due to sparse data with low exposure and event rates. PS adjustment resulted in greater power than propensity score matching, while controlling Type I error at 0.05. The PML method provided reasonable p-values, even in cases with complete separation, with well controlled Type I error rates. Using PS adjustment and the PML method, we identify novel latent drug effects in pediatric patients exposed to two common antibiotic drugs, ampicillin and gentamicin. R packages PheWAS and EHR are available at https://github.com/PheWAS/PheWAS and at CRAN (https://www.r-project.org/), respectively. The R script for data processing and the main analysis is available at https://github.com/choileena/EHR. leena.choi@vanderbilt.edu. Supplementary data are available at Bioinformatics online.

Discovering novel subsystems using comparative genomics

PubMed Central

Ferrer, Luciana; Shearer, Alexander G.; Karp, Peter D.

2011-01-01

Motivation: Key problems for computational genomics include discovering novel pathways in genome data, and discovering functional interaction partners for genes to define new members of partially elucidated pathways. Results: We propose a novel method for the discovery of subsystems from annotated genomes. For each gene pair, a score measuring the likelihood that the two genes belong to a same subsystem is computed using genome context methods. Genes are then grouped based on these scores, and the resulting groups are filtered to keep only high-confidence groups. Since the method is based on genome context analysis, it relies solely on structural annotation of the genomes. The method can be used to discover new pathways, find missing genes from a known pathway, find new protein complexes or other kinds of functional groups and assign function to genes. We tested the accuracy of our method in Escherichia coli K-12. In one configuration of the system, we find that 31.6% of the candidate groups generated by our method match a known pathway or protein complex closely, and that we rediscover 31.2% of all known pathways and protein complexes of at least 4 genes. We believe that a significant proportion of the candidates that do not match any known group in E.coli K-12 corresponds to novel subsystems that may represent promising leads for future laboratory research. We discuss in-depth examples of these findings. Availability: Predicted subsystems are available at http://brg.ai.sri.com/pwy-discovery/journal.html. Contact: lferrer@ai.sri.com Supplementary information: Supplementary data are available at Bioinformatics online. PMID:21775308

Ideal Standards, Acceptance, and Relationship Satisfaction: Latitudes of Differential Effects

PubMed Central

Buyukcan-Tetik, Asuman; Campbell, Lorne; Finkenauer, Catrin; Karremans, Johan C.; Kappen, Gesa

2017-01-01

We examined whether the relations of consistency between ideal standards and perceptions of a current romantic partner with partner acceptance and relationship satisfaction level off, or decelerate, above a threshold. We tested our hypothesis using a 3-year longitudinal data set collected from heterosexual newlywed couples. We used two indicators of consistency: pattern correspondence (within-person correlation between ideal standards and perceived partner ratings) and mean-level match (difference between ideal standards score and perceived partner score). Our results revealed that pattern correspondence had no relation with partner acceptance, but a positive linear/exponential association with relationship satisfaction. Mean-level match had a significant positive association with actor’s acceptance and relationship satisfaction up to the point where perceived partner score equaled ideal standards score. Partner effects did not show a consistent pattern. The results suggest that the consistency between ideal standards and perceived partner attributes has a non-linear association with acceptance and relationship satisfaction, although the results were more conclusive for mean-level match. PMID:29033876

Ulinastatin administration is associated with a lower incidence of acute kidney injury after cardiac surgery: a propensity score matched study.

PubMed

Wan, Xin; Xie, Xiangcheng; Gendoo, Yasser; Chen, Xin; Ji, Xiaobing; Cao, Changchun

2016-02-17

Systemic inflammation is involved in the development of acute kidney injury (AKI) after cardiac surgery with cardiopulmonary bypass (CPB). Ulinastatin, a urinary trypsin inhibitor (UTI), possesses a variety of anti-inflammatory effects. Therefore, we hypothesized that the administration of ulinastatin would reduce the occurrence of AKI in patients undergoing cardiac surgery with CPB. A retrospective propensity score matched analysis was used to evaluate the effect of ulinastatin on the development of AKI in patients undergoing first documented cardiac surgery with CPB between January 2008 and December 2012 in our hospital. Multiple logistic regression models were also employed to identify the association between UTI administration and development of AKI. A total of 2072 patients who underwent cardiac surgery with CPB met the inclusion criteria. Before propensity score matching, variables such as age, baseline creatinine, CPB duration, red blood cells transfused, and hematocrit were statistically different between the ulinastatin (UTI) group and the control group. On the basis of propensity scores, 409 UTI patients were successfully matched to the 409 patients from among those 1663 patients without UTI administration. After propensity score matching, no statistically significant differences in the baseline characteristics were found between the UTI group and the control group. The propensity score matched cohort analysis revealed that AKI and the need for renal replacement therapy occurred more frequently in the control group than in the UTI group (40.83% vs. 30.32%, P = 0.002; 2.44% vs. 0.49%, P = 0.02, respectively). However, there were no significant differences in mortality, length of intensive care unit stay, and length of hospital stay between the UTI group and the control group. Using multivariate logistic regression analysis, we found ulinastatin played a protective role in the development of AKI after cardiac surgery (odds ratio 0.71, 95% confidence interval 0.56-0.90, P = 0.005). This study shows that ulinastatin was associated with a lower incidence of AKI after cardiac surgery, suggesting that the administration of ulinastatin may be favorable for those patients undergoing cardiac surgery with CPB.

Eicosapentaenoic Acid (EPA) Decreases the All-Cause Mortality in Hemodialysis Patients.

PubMed

Inoue, Tomoko; Okano, Kazuhiro; Tsuruta, Yuki; Tsuruta, Yukio; Tsuchiya, Ken; Akiba, Takashi; Nitta, Kosaku

2015-01-01

Atherosclerosis, which causes cardiovascular disease, is a major cause of death in hemodialysis (HD) patients. Eicosapentaenoic acid (EPA), an anti-hyperlipidemic agent, is known to have antioxidative or anti-inflammatory effects, resulting in improvements in atherosclerosis. In the present study, we examined whether EPA improves the all-cause mortality in patients receiving regular HD therapy. We enrolled 176 patients treated with maintenance HD therapy and performed a longitudinal observational cohort study for three years. We divided the patients into two groups based on whether or not the received EPA treatment [EPA(+) and EPA(-), respectively]. The primary end-point was all-cause death. We also matched the two groups using propensity score matching and examined the effect of EPA. Before matching, the all-cause mortality rates were 24.0% in the EPA(+) and 11.8% in the EPA(-) groups, which were significantly different (p=0.044). After propensity score matching, the EPA(+) group still showed a significantly better prognosis than the EPA(-) group (p=0.038). A multivariate analysis showed that EPA treatment significantly reduced the risk of all-cause mortality both before and after propensity score matching. EPA treatment is independently associated with lower mortality in HD patients.

A Two-Step Bayesian Approach for Propensity Score Analysis: Simulations and Case Study.

PubMed

Kaplan, David; Chen, Jianshen

2012-07-01

A two-step Bayesian propensity score approach is introduced that incorporates prior information in the propensity score equation and outcome equation without the problems associated with simultaneous Bayesian propensity score approaches. The corresponding variance estimators are also provided. The two-step Bayesian propensity score is provided for three methods of implementation: propensity score stratification, weighting, and optimal full matching. Three simulation studies and one case study are presented to elaborate the proposed two-step Bayesian propensity score approach. Results of the simulation studies reveal that greater precision in the propensity score equation yields better recovery of the frequentist-based treatment effect. A slight advantage is shown for the Bayesian approach in small samples. Results also reveal that greater precision around the wrong treatment effect can lead to seriously distorted results. However, greater precision around the correct treatment effect parameter yields quite good results, with slight improvement seen with greater precision in the propensity score equation. A comparison of coverage rates for the conventional frequentist approach and proposed Bayesian approach is also provided. The case study reveals that credible intervals are wider than frequentist confidence intervals when priors are non-informative.

Effects of Internet and Smartphone Addictions on Depression and Anxiety Based on Propensity Score Matching Analysis.

PubMed

Kim, Yeon-Jin; Jang, Hye Min; Lee, Youngjo; Lee, Donghwan; Kim, Dai-Jin

2018-04-25

The associations of Internet addiction (IA) and smartphone addiction (SA) with mental health problems have been widely studied. We investigated the effects of IA and SA on depression and anxiety while adjusting for sociodemographic variables. In this study, 4854 participants completed a cross-sectional web-based survey including socio-demographic items, the Korean Scale for Internet Addiction, the Smartphone Addiction Proneness Scale, and the subscales of the Symptom Checklist 90 Items-Revised. The participants were classified into IA, SA, and normal use (NU) groups. To reduce sampling bias, we applied the propensity score matching method based on genetics matching. The IA group showed an increased risk of depression (relative risk 1.207; p < 0.001) and anxiety (relative risk 1.264; p < 0.001) compared to NUs. The SA group also showed an increased risk of depression (relative risk 1.337; p < 0.001) and anxiety (relative risk 1.402; p < 0.001) compared to NCs. These findings show that both, IA and SA, exerted significant effects on depression and anxiety. Moreover, our findings showed that SA has a stronger relationship with depression and anxiety, stronger than IA, and emphasized the need for prevention and management policy of the excessive smartphone use.

Brachytherapy improves biochemical failure-free survival in low- and intermediate-risk prostate cancer compared with conventionally fractionated external beam radiation therapy: a propensity score matched analysis.

PubMed

Smith, Graham D; Pickles, Tom; Crook, Juanita; Martin, Andre-Guy; Vigneault, Eric; Cury, Fabio L; Morris, Jim; Catton, Charles; Lukka, Himu; Warner, Andrew; Yang, Ying; Rodrigues, George

2015-03-01

To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2) intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Propensity score matched analysis showed that BT options led to statistically significant improvements in bFFS in low- and intermediate-risk prostate cancer patient populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Perceived fairness of pay among people with and without disabilities: a propensity score matched analysis of working Australians.

PubMed

Milner, Allison; Aitken, Zoe; Krnjacki, Lauren; Bentley, Rebecca; Blakely, Tony; LaMontagne, Anthony D; Kavanagh, Anne M

2015-09-01

Equity and fairness at work are associated with a range of organizational and health outcomes. Past research suggests that workers with disabilities experience inequity in the workplace. It is difficult to conclude whether the presence of disability is the reason for perceived unfair treatment due to the possible confounding of effect estimates by other demographic or socioeconomic factors. The data source was the Household, Income, and Labor Dynamics in Australia (HILDA) survey (2001-2012). Propensity for disability was calculated from logistic models including gender, age, education, country of birth, and father's occupational skill level as predictors. We then used nearest neighbor (on propensity score) matched analysis to match workers with disabilities to workers without disability. Results suggest that disability is independently associated with lower fairness of pay after controlling for confounding factors in the propensity score matched analysis; although results do suggest less than half a standard deviation difference, indicating small effects. Similar results were apparent in standard multivariable regression models and alternative propensity score analyses (stratification, covariate adjustment using the propensity score, and inverse probability of treatment weighting). Whilst neither multivariable regression nor propensity scores adjust for unmeasured confounding, and there remains the potential for other biases, similar results for the two methodological approaches to confounder adjustment provide some confidence of an independent association of disability with perceived unfairness of pay. Based on this, we suggest that the disparity in the perceived fairness of pay between people with and without disabilities may be explained by worse treatment of people with disabilities in the workplace.

Prenatal exposure to maternal smoking and childhood behavioural problems: a quasi-experimental approach.

PubMed

McCrory, Cathal; Layte, Richard

2012-11-01

This retrospective cross-sectional paper examines the relationship between maternal smoking during pregnancy and children's behavioural problems at 9 years of age independent of a wide range of possible confounders. The final sample comprised 7,505 nine-year-old school children participating in the first wave of the Growing Up in Ireland study. The children were selected through the Irish national school system using a 2-stage sampling method and were representative of the nine-year population. Information on maternal smoking during pregnancy was obtained retrospectively at 9 years of age via parental recall and children's behavioural problems were assessed using the Strengths and Difficulties Questionnaire across separate parent and teacher-report instruments. A quasi-experimental approach using propensity score matching was used to create treatment (smoking) and control (non-smoking) groups which did not differ significantly in their propensity to smoke in terms of 16 observed characteristics. After matching on the propensity score, children whose mothers smoked during pregnancy were 3.5 % (p < 0.001) and 3.4 % (p < 0.001) more likely to score in the problematic range on the SDQ total difficulties index according to parent and teacher-report respectively. Maternal smoking during pregnancy was more strongly associated with externalising than internalising behavioural problems. Analysis of the dose-response relationship showed that the differential between matched treatment and control groups increased with level of maternal smoking. Given that smoking is a modifiable risk factor, the promotion of successful cessation in pregnancy may prevent potentially adverse long-term consequences.

Comparison of reporting phase I trial results in ClinicalTrials.gov and matched publications.

PubMed

Shepshelovich, D; Goldvaser, H; Wang, L; Abdul Razak, A R; Bedard, P L

2017-12-01

Background Data on completeness of reporting of phase I cancer clinical trials in publications are lacking. Methods The ClinicalTrials.gov database was searched for completed adult phase I cancer trials with reported results. PubMed was searched for matching primary publications published prior to November 1, 2016. Reporting in primary publications was compared with the ClinicalTrials.gov database using a 28-point score (2=complete; 1=partial; 0=no reporting) for 14 items related to study design, outcome measures and safety profile. Inconsistencies between primary publications and ClinicalTrials.gov were recorded. Linear regression was used to identify factors associated with incomplete reporting. Results After a review of 583 trials in ClinicalTrials.gov , 163 matching primary publications were identified. Publications reported outcomes that did not appear in ClinicalTrials.gov in 25% of trials. Outcomes were upgraded, downgraded or omitted in publications in 47% of trials. The overall median reporting score was 23/28 (interquartile range 21-25). Incompletely reported items in >25% publications were: inclusion criteria (29%), primary outcome definition (26%), secondary outcome definitions (53%), adverse events (71%), serious adverse events (80%) and dates of study start and database lock (91%). Higher reporting scores were associated with phase I (vs phase I/II) trials (p<0.001), multicenter trials (p<0.001) and publication in journals with lower impact factor (p=0.004). Conclusions Reported results in primary publications for early phase cancer trials are frequently inconsistent or incomplete compared with ClinicalTrials.gov entries. ClinicalTrials.gov may provide more comprehensive data from new cancer drug trials.

Exponential series approaches for nonparametric graphical models

NASA Astrophysics Data System (ADS)

Janofsky, Eric

Markov Random Fields (MRFs) or undirected graphical models are parsimonious representations of joint probability distributions. This thesis studies high-dimensional, continuous-valued pairwise Markov Random Fields. We are particularly interested in approximating pairwise densities whose logarithm belongs to a Sobolev space. For this problem we propose the method of exponential series which approximates the log density by a finite-dimensional exponential family with the number of sufficient statistics increasing with the sample size. We consider two approaches to estimating these models. The first is regularized maximum likelihood. This involves optimizing the sum of the log-likelihood of the data and a sparsity-inducing regularizer. We then propose a variational approximation to the likelihood based on tree-reweighted, nonparametric message passing. This approximation allows for upper bounds on risk estimates, leverages parallelization and is scalable to densities on hundreds of nodes. We show how the regularized variational MLE may be estimated using a proximal gradient algorithm. We then consider estimation using regularized score matching. This approach uses an alternative scoring rule to the log-likelihood, which obviates the need to compute the normalizing constant of the distribution. For general continuous-valued exponential families, we provide parameter and edge consistency results. As a special case we detail a new approach to sparse precision matrix estimation which has statistical performance competitive with the graphical lasso and computational performance competitive with the state-of-the-art glasso algorithm. We then describe results for model selection in the nonparametric pairwise model using exponential series. The regularized score matching problem is shown to be a convex program; we provide scalable algorithms based on consensus alternating direction method of multipliers (ADMM) and coordinate-wise descent. We use simulations to compare our method to others in the literature as well as the aforementioned TRW estimator.

Tracking quasi-stationary flow of weak fluorescent signals by adaptive multi-frame correlation.

PubMed

Ji, L; Danuser, G

2005-12-01

We have developed a novel cross-correlation technique to probe quasi-stationary flow of fluorescent signals in live cells at a spatial resolution that is close to single particle tracking. By correlating image blocks between pairs of consecutive frames and integrating their correlation scores over multiple frame pairs, uncertainty in identifying a globally significant maximum in the correlation score function has been greatly reduced as compared with conventional correlation-based tracking using the signal of only two consecutive frames. This approach proves robust and very effective in analysing images with a weak, noise-perturbed signal contrast where texture characteristics cannot be matched between only a pair of frames. It can also be applied to images that lack prominent features that could be utilized for particle tracking or feature-based template matching. Furthermore, owing to the integration of correlation scores over multiple frames, the method can handle signals with substantial frame-to-frame intensity variation where conventional correlation-based tracking fails. We tested the performance of the method by tracking polymer flow in actin and microtubule cytoskeleton structures labelled at various fluorophore densities providing imagery with a broad range of signal modulation and noise. In applications to fluorescent speckle microscopy (FSM), where the fluorophore density is sufficiently low to reveal patterns of discrete fluorescent marks referred to as speckles, we combined the multi-frame correlation approach proposed above with particle tracking. This hybrid approach allowed us to follow single speckles robustly in areas of high speckle density and fast flow, where previously published FSM analysis methods were unsuccessful. Thus, we can now probe cytoskeleton polymer dynamics in living cells at an entirely new level of complexity and with unprecedented detail.

The Physician Recommendation Coding System (PhyReCS): A Reliable and Valid Method to Quantify the Strength of Physician Recommendations During Clinical Encounters

PubMed Central

Scherr, Karen A.; Fagerlin, Angela; Williamson, Lillie D.; Davis, J. Kelly; Fridman, Ilona; Atyeo, Natalie; Ubel, Peter A.

2016-01-01

Background Physicians’ recommendations affect patients’ treatment choices. However, most research relies on physicians’ or patients’ retrospective reports of recommendations, which offer a limited perspective and have limitations such as recall bias. Objective To develop a reliable and valid method to measure the strength of physician recommendations using direct observation of clinical encounters. Methods Clinical encounters (n = 257) were recorded as part of a larger study of prostate cancer decision making. We used an iterative process to create the 5-point Physician Recommendation Coding System (PhyReCS). To determine reliability, research assistants double-coded 50 transcripts. To establish content validity, we used one-way ANOVAs to determine whether relative treatment recommendation scores differed as a function of which treatment patients received. To establish concurrent validity, we examined whether patients’ perceived treatment recommendations matched our coded recommendations. Results The PhyReCS was highly reliable (Krippendorf’s alpha =. 89, 95% CI [.86, .91]). The average relative treatment recommendation score for each treatment was higher for individuals who received that particular treatment. For example, the average relative surgery recommendation score was higher for individuals who received surgery versus radiation (mean difference = .98, SE = .18, p < .001) or active surveillance (mean difference = 1.10, SE = .14, p < .001). Patients’ perceived recommendations matched coded recommendations 81% of the time. Conclusion The PhyReCS is a reliable and valid way to capture the strength of physician recommendations. We believe that the PhyReCS would be helpful for other researchers who wish to study physician recommendations, an important part of patient decision making. PMID:27343015

Pharmacophore-Based Similarity Scoring for DOCK

PubMed Central

2015-01-01

Pharmacophore modeling incorporates geometric and chemical features of known inhibitors and/or targeted binding sites to rationally identify and design new drug leads. In this study, we have encoded a three-dimensional pharmacophore matching similarity (FMS) scoring function into the structure-based design program DOCK. Validation and characterization of the method are presented through pose reproduction, crossdocking, and enrichment studies. When used alone, FMS scoring dramatically improves pose reproduction success to 93.5% (∼20% increase) and reduces sampling failures to 3.7% (∼6% drop) compared to the standard energy score (SGE) across 1043 protein–ligand complexes. The combined FMS+SGE function further improves success to 98.3%. Crossdocking experiments using FMS and FMS+SGE scoring, for six diverse protein families, similarly showed improvements in success, provided proper pharmacophore references are employed. For enrichment, incorporating pharmacophores during sampling and scoring, in most cases, also yield improved outcomes when docking and rank-ordering libraries of known actives and decoys to 15 systems. Retrospective analyses of virtual screenings to three clinical drug targets (EGFR, IGF-1R, and HIVgp41) using X-ray structures of known inhibitors as pharmacophore references are also reported, including a customized FMS scoring protocol to bias on selected regions in the reference. Overall, the results and fundamental insights gained from this study should benefit the docking community in general, particularly researchers using the new FMS method to guide computational drug discovery with DOCK. PMID:25229837

Best (but oft-forgotten) practices: propensity score methods in clinical nutrition research.

PubMed

Ali, M Sanni; Groenwold, Rolf Hh; Klungel, Olaf H

2016-08-01

In observational studies, treatment assignment is a nonrandom process and treatment groups may not be comparable in their baseline characteristics, a phenomenon known as confounding. Propensity score (PS) methods can be used to achieve comparability of treated and nontreated groups in terms of their observed covariates and, as such, control for confounding in estimating treatment effects. In this article, we provide a step-by-step guidance on how to use PS methods. For illustrative purposes, we used simulated data based on an observational study of the relation between oral nutritional supplementation and hospital length of stay. We focused on the key aspects of PS analysis, including covariate selection, PS estimation, covariate balance assessment, treatment effect estimation, and reporting. PS matching, stratification, covariate adjustment, and weighting are discussed. R codes and example data are provided to show the different steps in a PS analysis. © 2016 American Society for Nutrition.

A LiDAR data-based camera self-calibration method

NASA Astrophysics Data System (ADS)

Xu, Lijun; Feng, Jing; Li, Xiaolu; Chen, Jianjun

2018-07-01

To find the intrinsic parameters of a camera, a LiDAR data-based camera self-calibration method is presented here. Parameters have been estimated using particle swarm optimization (PSO), enhancing the optimal solution of a multivariate cost function. The main procedure of camera intrinsic parameter estimation has three parts, which include extraction and fine matching of interest points in the images, establishment of cost function, based on Kruppa equations and optimization of PSO using LiDAR data as the initialization input. To improve the precision of matching pairs, a new method of maximal information coefficient (MIC) and maximum asymmetry score (MAS) was used to remove false matching pairs based on the RANSAC algorithm. Highly precise matching pairs were used to calculate the fundamental matrix so that the new cost function (deduced from Kruppa equations in terms of the fundamental matrix) was more accurate. The cost function involving four intrinsic parameters was minimized by PSO for the optimal solution. To overcome the issue of optimization pushed to a local optimum, LiDAR data was used to determine the scope of initialization, based on the solution to the P4P problem for camera focal length. To verify the accuracy and robustness of the proposed method, simulations and experiments were implemented and compared with two typical methods. Simulation results indicated that the intrinsic parameters estimated by the proposed method had absolute errors less than 1.0 pixel and relative errors smaller than 0.01%. Based on ground truth obtained from a meter ruler, the distance inversion accuracy in the experiments was smaller than 1.0 cm. Experimental and simulated results demonstrated that the proposed method was highly accurate and robust.

A comparative study between xerographic, computer-assisted overlay generation and animated-superimposition methods in bite mark analyses.

PubMed

Tai, Meng Wei; Chong, Zhen Feng; Asif, Muhammad Khan; Rahmat, Rabiah A; Nambiar, Phrabhakaran

2016-09-01

This study was to compare the suitability and precision of xerographic and computer-assisted methods for bite mark investigations. Eleven subjects were asked to bite on their forearm and the bite marks were photographically recorded. Alginate impressions of the subjects' dentition were taken and their casts were made using dental stone. The overlays generated by xerographic method were obtained by photocopying the subjects' casts and the incisal edge outlines were then transferred on a transparent sheet. The bite mark images were imported into Adobe Photoshop® software and printed to life-size. The bite mark analyses using xerographically generated overlays were done by comparing an overlay to the corresponding printed bite mark images manually. In computer-assisted method, the subjects' casts were scanned into Adobe Photoshop®. The bite mark analyses using computer-assisted overlay generation were done by matching an overlay and the corresponding bite mark images digitally using Adobe Photoshop®. Another comparison method was superimposing the cast images with corresponding bite mark images employing the Adobe Photoshop® CS6 and GIF-Animator©. A score with a range of 0-3 was given during analysis to each precision-determining criterion and the score was increased with better matching. The Kruskal Wallis H test showed significant difference between the three sets of data (H=18.761, p<0.05). In conclusion, bite mark analysis using the computer-assisted animated-superimposition method was the most accurate, followed by the computer-assisted overlay generation and lastly the xerographic method. The superior precision contributed by digital method is discernible despite the human skin being a poor recording medium of bite marks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Word associations contribute to machine learning in automatic scoring of degree of emotional tones in dream reports.

PubMed

Amini, Reza; Sabourin, Catherine; De Koninck, Joseph

2011-12-01

Scientific study of dreams requires the most objective methods to reliably analyze dream content. In this context, artificial intelligence should prove useful for an automatic and non subjective scoring technique. Past research has utilized word search and emotional affiliation methods, to model and automatically match human judges' scoring of dream report's negative emotional tone. The current study added word associations to improve the model's accuracy. Word associations were established using words' frequency of co-occurrence with their defining words as found in a dictionary and an encyclopedia. It was hypothesized that this addition would facilitate the machine learning model and improve its predictability beyond those of previous models. With a sample of 458 dreams, this model demonstrated an improvement in accuracy from 59% to 63% (kappa=.485) on the negative emotional tone scale, and for the first time reached an accuracy of 77% (kappa=.520) on the positive scale. Copyright © 2011 Elsevier Inc. All rights reserved.

Estimating Treatment Effects via Multilevel Matching within Homogenous Groups of Clusters

ERIC Educational Resources Information Center

Steiner, Peter M.; Kim, Jee-Seon

2015-01-01

Despite the popularity of propensity score (PS) techniques they are not yet well studied for matching multilevel data where selection into treatment takes place among level-one units within clusters. This paper suggests a PS matching strategy that tries to avoid the disadvantages of within- and across-cluster matching. The idea is to first…

Assessing the Effectiveness of the Functional Movement Screen in Predicting Noncontact Injury Rates in Soccer Players.

PubMed

Smith, Paul D; Hanlon, Michael P

2017-12-01

Smith, PD, and Hanlon, D. Assessing the effectiveness of the functional movement screen in predicting noncontact injury rates in soccer players. J Strength Cond Res 31(12): 3327-3332, 2017-This study assessed if the Functional Movement Screen (FMS) can accurately predict noncontact injury in adult soccer players when normalizing noncontact injury occurrence against match exposure levels. Senior male players (n = 89) from 5 League of Ireland semiprofessional clubs participated in the study (mean age = 23.2 ± 4.4 years; mean height = 179.5 ± 6.6 cm; mean body mass = 77.5 ± 7.8 kg). Participants performed the FMS during preseason, and their injury occurrence rates and match minutes were tracked throughout 1 season. In total, 66 noncontact injuries were recorded. No significant difference was found in FMS composite scores between players receiving noncontact injuries and players not suffering a noncontact injury (p = 0.96). There was no significant difference in exposure-normalized noncontact injury incidence between those scoring 14 or below and those scoring above 14 on the FMS (0.36 vs. 0.29 non-contact injuries per player per 1,000 match minutes). Players scoring 14 or below on the FMS had an odds ratio of 0.63 (p = 0.45; 95% CI = 0.19-2.07) of receiving a noncontact injury. Despite previous research showing links between low FMS composite scores and subsequent injury, these results suggest that the FMS cannot accurately predict a male soccer player's likelihood of receiving a noncontact injury and that a lower FMS composite score does not significantly increase their noncontact injury incidence rate per 1,000 match minutes. Caution should therefore be used when using the FMS as a predictor of noncontact injury, and pain prevalence during the FMS, previous injuries, and training/match exposure levels should also be taken into account.

Retrieval of memories with the help of music in Alzheimer's disease.

PubMed

Chevreau, Priscilia; Nizard, Ingrid; Allain, Philippe

2017-09-01

This study focuses on music as a mediator facilitating access to autobiographical memory in Alzheimer's disease (AD). Studies on this topic are rare, but available data have shown a beneficial effect of music on autobiographical performance in AD patients. Based on the "index word" method, we developed the "index music" method for the evaluation of autobiographical memory. The subjects had to tell a memory of their choice from the words or music presented to them. The task was proposed to 54 patients with diagnosis of AD according to DSM IV and NINCDS-ADRDA criteria. All of them had a significant cognitive decline on the MMSE (mean score: 14.5). Patients were matched by age, sex and level of education with 48 control subjects without cognitive impairment (mean score on the MMSE: 28). Results showed that autobiographical memory quantity scores of AD patients were significantly lower than those of healthy control in both methods. However, autobiographical memory quality scores of AD patients increased with "index music" whereas autobiographical memory quality scores of healthy control decreased. Also, the autobiographical performance of patients with AD in condition index music was not correlated with cognitive performance in contrast to the autobiographical performances in index word. These results confirm that music improves access to personal memories in patients with AD. Personal memories could be preserved in patients with AD and music could constitute an interesting way to stimulate recollection.

Cataract influence on iris recognition performance

NASA Astrophysics Data System (ADS)

Trokielewicz, Mateusz; Czajka, Adam; Maciejewicz, Piotr

2014-11-01

This paper presents the experimental study revealing weaker performance of the automatic iris recognition methods for cataract-affected eyes when compared to healthy eyes. There is little research on the topic, mostly incorporating scarce databases that are often deficient in images representing more than one illness. We built our own database, acquiring 1288 eye images of 37 patients of the Medical University of Warsaw. Those images represent several common ocular diseases, such as cataract, along with less ordinary conditions, such as iris pattern alterations derived from illness or eye trauma. Images were captured in near-infrared light (used in biometrics) and for selected cases also in visible light (used in ophthalmological diagnosis). Since cataract is a disorder that is most populated by samples in the database, in this paper we focus solely on this illness. To assess the extent of the performance deterioration we use three iris recognition methodologies (commercial and academic solutions) to calculate genuine match scores for healthy eyes and those influenced by cataract. Results show a significant degradation in iris recognition reliability manifesting by worsening the genuine scores in all three matchers used in this study (12% of genuine score increase for an academic matcher, up to 175% of genuine score increase obtained for an example commercial matcher). This increase in genuine scores affected the final false non-match rate in two matchers. To our best knowledge this is the only study of such kind that employs more than one iris matcher, and analyzes the iris image segmentation as a potential source of decreased reliability

Right anterior mini-thoracotomy vs. conventional sternotomy for aortic valve replacement: a propensity-matched comparison

PubMed Central

Del Giglio, Mauro; Mikus, Elisa; Micari, Antonio; Calvi, Simone; Tripodi, Alberto; Campo, Gianluca; Maietti, Elisa; Castriota, Fausto; Cremonesi, Alberto

2018-01-01

Background Right anterior mini-thoracotomy (MIAVR) is a promising technique for aortic valve replacement. We aimed at comparing its outcomes with those obtained in a propensity-matched group of patients undergoing sternotomy at our two high-volume centers. Methods Main clinical and operative data of patients undergoing aortic valve replacement between January 2010 and May 2016 were retrospectively collected. A total of 678 patients were treated with a standard full sternotomy approach, while MIAVR was performed in 502. Propensity score matching identified 363 patients per each group. Results In-hospital mortality was not significantly different between the propensity-matched groups (1.7% in MIAVR patients vs. 2.2% in conventional sternotomy patients; P=0.79). No significant difference in the incidence of major post-operative complications was observed. Post-operative ventilation times (median 7, range 5–12 hours in MIAVR patients vs. median 7, range 5–12 in conventional sternotomy patients; P=0.72) were not significantly different between the two groups. Cardiopulmonary bypass time (61.0±21.0 vs. 65.9±24.7 min in conventional sternotomy group; P<0.01) and aortic cross-clamping time (48.3±16.7 vs. 53.2±19.6 min in full sternotomy group; P<0.01) were shorter in MIAVR group. EuroSCORE (OR 1.52, 95% CI, 1.12–2.06; P<0.01) was found to be the only independent predictor of intra-hospital mortality in the whole propensity-matched population. Conclusions Our experience shows that mini-access isolated aortic valve surgery is a reproducible, safe and effective procedure with similar outcomes and no longer operative times compared to conventional sternotomy. PMID:29707310

Are older adults living in more equal counties healthier than older adults living in more unequal counties? A propensity score matching approach.

PubMed

Choi, HwaJung; Burgard, Sarah; Elo, Irma T; Heisler, Michele

2015-09-01

We assessed the potential contextual effect of income inequality on health by: 1) comparing individuals with similar socioeconomic status (SES) but who reside in counties with different levels of income inequality; and 2) examining whether the potential effect of county-level income inequality on health varies across SES groups. We used the Health and Retirement Study, a nationally representative study of Americans over the age of 50. Using propensity score matching, we selected SES-comparable individuals living in high-income inequality counties and in low-income inequality counties. We examined differences in self-rated overall health outcomes and in other specific physical/mental health outcomes between the two groups using logistic regression (n = 34,994) and imposing different sample restrictions based on residential duration in the area. We then used logistic regression with interactions to assess whether, and if so how, health outcomes differed among participants of different SES groups defined by wealth, income, and education. In bivariate analyses of the unmatched full sample, adults living in high-income inequality counties have worse health outcomes for most health measures. After propensity score matching, adults in high-income inequality counties had worse self-rated health status (AOR = 1.12; 95% CI 1.04-1.19) and were more likely to report diagnosed psychiatric problems (AOR = 1.08; 95% CI 0.99-1.19) than their matched counterparts in low-income inequality counties. These associations were stronger with longer-term residents in the area. Adverse health outcomes associated with living in high-income inequality counties were significant particularly for individuals in the 30(th) or greater percentiles of income/wealth distribution and those without a college education. In summary, after using more precise matching methods to compare individuals with similar characteristics and addressing measurement error by excluding more recently arrived county residents, adults living in high-income inequality counties had worse reported overall physical and mental health than adults living in low-income inequality counties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are older adults living in more equal counties healthier than older adults living in more unequal counties? A propensity score matching approach

PubMed Central

Choi, HwaJung; Burgard, Sarah; Elo, Irma T.; Heisler, Michele

2015-01-01

We assessed the potential contextual effect of income inequality on health by: 1) comparing individuals with similar socioeconomic status (SES) but who reside in counties with different levels of income inequality; and 2) examining whether the potential effect of county-level income inequality on health varies across SES groups. We used the Health and Retirement Study, a nationally representative study of Americans over the age of 50. Using propensity score matching, we selected SES-comparable individuals living in high-income inequality counties and in low-income inequality counties. We examined differences in self-rated overall health outcomes and in other specific physical/mental health outcomes between the two groups using logistic regression (n=34,994) and imposing different sample restrictions based on residential duration in the area. We then used logistic regression with interactions to assess whether, and if so how, health outcomes differed among participants of different SES groups defined by wealth, income, and education. In bivariate analyses of the unmatched full sample, adults living in high-income inequality counties have worse health outcomes for most health measures. After propensity score matching, adults in high-income inequality counties had worse self-rated health status (AOR=1.12; 95% CI 1.04–1.19) and were more likely to report diagnosed psychiatric problems (AOR=1.08; 95% CI 0.99–1.19) than their matched counterparts in low-income inequality counties. These associations were stronger with longer-term residents in the area. Adverse health outcomes associated with living in high-income inequality counties were significant particularly for individuals in the 30th or greater percentiles of income/wealth distribution and those without a college education. In summary, after using more precise matching methods to compare individuals with similar characteristics and addressing measurement error by excluding more recently arrived county residents, adults living in high-income inequality counties had worse reported overall physical and mental health than adults living in low-income inequality counties. PMID:26256736

Potential Pitfalls of Reporting and Bias in Observational Studies With Propensity Score Analysis Assessing a Surgical Procedure: A Methodological Systematic Review.

PubMed

Lonjon, Guillaume; Porcher, Raphael; Ergina, Patrick; Fouet, Mathilde; Boutron, Isabelle

2017-05-01

To describe the evolution of the use and reporting of propensity score (PS) analysis in observational studies assessing a surgical procedure. Assessing surgery in randomized controlled trials raises several challenges. Observational studies with PS analysis are a robust alternative for comparative effectiveness research. In this methodological systematic review, we identified all PubMed reports of observational studies with PS analysis that evaluated a surgical procedure and described the evolution of their use over time. Then, we selected a sample of articles published from August 2013 to July 2014 and systematically appraised the quality of reporting and potential bias of the PS analysis used. We selected 652 reports of observational studies with PS analysis. The publications increased over time, from 1 report in 1987 to 198 in 2013. Among the 129 reports assessed, 20% (n = 24) did not detail the covariates included in the PS and 77% (n = 100) did not report a justification for including these covariates in the PS. The rate of missing data for potential covariates was reported in 9% of articles. When a crossover by conversion was possible, only 14% of reports (n = 12) mentioned this issue. For matched analysis, 10% of articles reported all 4 key elements that allow for reproducibility of a PS-matched analysis (matching ratio, method to choose the nearest neighbors, replacement and method for statistical analysis). Observational studies with PS analysis in surgery are increasing in frequency, but specific methodological issues and weaknesses in reporting exist.

Usefulness of the group-comparison method to demonstrate sex differences in spatial orientation and spatial visualization in older men and women.

PubMed

Cohen, D

1976-10-01

This paper reports an analysis of sex differences in cognitive test scores covering the dimensions of spatial orientation and spatial visualization in groups of 6 older men and 6 women matched for speed of performance on a maze test and level of performance on a spatial relations task. Older men were more proficient solving spatial problems using the body as a referent, whereas there was no significant difference between the sexes in imagining spatial displacement. Matched comparisons appear a useful adjunct to population research to understand the type(s) of cognitive processes where differential performance by the sexes is observed.

Sensors vs. experts - a performance comparison of sensor-based fall risk assessment vs. conventional assessment in a sample of geriatric patients.

PubMed

Marschollek, Michael; Rehwald, Anja; Wolf, Klaus-Hendrik; Gietzelt, Matthias; Nemitz, Gerhard; zu Schwabedissen, Hubertus Meyer; Schulze, Mareike

2011-06-28

Fall events contribute significantly to mortality, morbidity and costs in our ageing population. In order to identify persons at risk and to target preventive measures, many scores and assessment tools have been developed. These often require expertise and are costly to implement. Recent research investigates the use of wearable inertial sensors to provide objective data on motion features which can be used to assess individual fall risk automatically. So far it is unknown how well this new method performs in comparison with conventional fall risk assessment tools. The aim of our research is to compare the predictive performance of our new sensor-based method with conventional and established methods, based on prospective data. In a first study phase, 119 inpatients of a geriatric clinic took part in motion measurements using a wireless triaxial accelerometer during a Timed Up&Go (TUG) test and a 20 m walk. Furthermore, the St. Thomas Risk Assessment Tool in Falling Elderly Inpatients (STRATIFY) was performed, and the multidisciplinary geriatric care team estimated the patients' fall risk. In a second follow-up phase of the study, 46 of the participants were interviewed after one year, including a fall and activity assessment. The predictive performances of the TUG, the STRATIFY and team scores are compared. Furthermore, two automatically induced logistic regression models based on conventional clinical and assessment data (CONV) as well as sensor data (SENSOR) are matched. Among the risk assessment scores, the geriatric team score (sensitivity 56%, specificity 80%) outperforms STRATIFY and TUG. The induced logistic regression models CONV and SENSOR achieve similar performance values (sensitivity 68%/58%, specificity 74%/78%, AUC 0.74/0.72, +LR 2.64/2.61). Both models are able to identify more persons at risk than the simple scores. Sensor-based objective measurements of motion parameters in geriatric patients can be used to assess individual fall risk, and our prediction model's performance matches that of a model based on conventional clinical and assessment data. Sensor-based measurements using a small wearable device may contribute significant information to conventional methods and are feasible in an unsupervised setting. More prospective research is needed to assess the cost-benefit relation of our approach.

Using Mahalanobis Distance Scores for Matched Pairing of Schools in a Randomized Controlled Trial Study of Leadership and Assistance for Science Education Reform (LASER)

ERIC Educational Resources Information Center

Zoblotsky, Todd; Ransford-Kaldon, Carolyn; Morrison, Donald M.

2011-01-01

The present paper describes the recruitment and site selection process that has been underway since January 2011, with particular emphasis on the use of Mahalanobis distance score to determine matched pairs of sites prior to randomization to treatment and control groups. Through a systematic winnowing process, the authors found that they could…

Evaluation of the US Food and Drug Administration sentinel analysis tools in confirming previously observed drug-outcome associations: The case of clindamycin and Clostridium difficile infection.

PubMed

Carnahan, Ryan M; Kuntz, Jennifer L; Wang, Shirley V; Fuller, Candace; Gagne, Joshua J; Leonard, Charles E; Hennessy, Sean; Meyer, Tamra; Archdeacon, Patrick; Chen, Chih-Ying; Panozzo, Catherine A; Toh, Sengwee; Katcoff, Hannah; Woodworth, Tiffany; Iyer, Aarthi; Axtman, Sophia; Chrischilles, Elizabeth A

2018-03-13

The Food and Drug Administration's Sentinel System developed parameterized, reusable analytic programs for evaluation of medical product safety. Research on outpatient antibiotic exposures, and Clostridium difficile infection (CDI) with non-user reference groups led us to expect a higher rate of CDI among outpatient clindamycin users vs penicillin users. We evaluated the ability of the Cohort Identification and Descriptive Analysis and Propensity Score Matching tools to identify a higher rate of CDI among clindamycin users. We matched new users of outpatient dispensings of oral clindamycin or penicillin from 13 Data Partners 1:1 on propensity score and followed them for up to 60 days for development of CDI. We used Cox proportional hazards regression stratified by Data Partner and matched pair to compare CDI incidence. Propensity score models at 3 Data Partners had convergence warnings and a limited range of predicted values. We excluded these Data Partners despite adequate covariate balance after matching. From the 10 Data Partners where these models converged without warnings, we identified 807 919 new clindamycin users and 8 815 441 new penicillin users eligible for the analysis. The stratified analysis of 807 769 matched pairs included 840 events among clindamycin users and 290 among penicillin users (hazard ratio 2.90, 95% confidence interval 2.53, 3.31). This evaluation produced an expected result and identified several potential enhancements to the Propensity Score Matching tool. This study has important limitations. CDI risk may have been related to factors other than the inherent properties of the drugs, such as duration of use or subsequent exposures. Copyright © 2018 John Wiley & Sons, Ltd.

Moving to a Highly Walkable Neighborhood and Incidence of Hypertension: A Propensity-Score Matched Cohort Study.

PubMed

Chiu, Maria; Rezai, Mohammad-Reza; Maclagan, Laura C; Austin, Peter C; Shah, Baiju R; Redelmeier, Donald A; Tu, Jack V

2016-06-01

The impact of moving to a neighborhood more conducive to utilitarian walking on the risk of incident hypertension is uncertain. Our study aimed to examine the effect of moving to a highly walkable neighborhood on the risk of incident hypertension. A population-based propensity-score matched cohort study design was used based on the Ontario population from the Canadian Community Health Survey (2001-2010). Participants were adults ≥ 20 years of age who moved from a low-walkability neighborhood (defined as any neighborhood with a Walk Score < 90) to either a high- (Walk Score ≥ 90) or another low-walkability neighborhood. The incidence of hypertension was assessed by linking the cohort to administrative health databases using a validated algorithm. Propensity-score matched Cox proportional hazard models were used. Annual health examination was used as a control event. Among the 1,057 propensity-score matched pairs there was a significantly lower risk of incident hypertension in the low to high vs. the low to low-walkability groups [hazard ratio = 0.46; 95% CI, 0.26, 0.81, p < 0.01]. The crude hypertension incidence rates were 18.0 per 1,000 person-years (95% CI: 11.6, 24.8) among the low- to low-walkability movers compared with 8.6 per 1,000 person-years (95% CI: 5.3, 12.7) among the low- to high-walkability movers (p < 0.001). There were no significant differences in the hazard of annual health examination between the two mover groups. Moving to a highly walkable neighborhood was associated with a significantly lower risk of incident hypertension. Future research should assess whether specific attributes of walkable neighborhoods (e.g., amenities, density, land-use mix) may be driving this relationship. Chiu M, Rezai MR, Maclagan LC, Austin PC, Shah BR, Redelmeier DA, Tu JV. 2016. Moving to a highly walkable neighborhood and incidence of hypertension: a propensity-score matched cohort study. Environ Health Perspect 124:754-760; http://dx.doi.org/10.1289/ehp.1510425.

Evaluation of a disease management program for COPD using propensity matched control group

PubMed Central

George, Pradeep Paul; Heng, Bee Hoon; Lim, Tow Keang; Abisheganaden, John; Ng, Alan Wei Keong; Lim, Fong Seng

2016-01-01

Background Disease management programs (DMPs) have proliferated recently as a means of improving the quality and efficiency of care for patients with chronic illness. These programs include education about disease, optimization of evidence-based medications, information and support from case managers, and institution of self-management principles. Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in Singapore and worldwide. DMP aims to reduce mortality, hospitalizations, and average length of stay in such patients. This study assesses the outcomes of the DMP, comparing the propensity score matched DMP patients with controls. Methods DMP patients were compared with the controls, who were COPD patients fulfilling the DMP’s inclusion criteria but not included in the program. Control patients were identified from Operations Data Store (ODS) database. The outcomes of interest were average length of stay, number of days admitted to hospital per 100 person days, readmission, and mortality rates per person year. The risk of death and readmission was estimated using Cox, and competing risk regression respectively. Propensity score was estimated to identify the predictors of DMP enrolment. DMP patients and controls were matched on their propensity score. Results There were 170 matched DMP patients and control patients having 287 and 207 hospitalizations respectively. Program patient had lower mortality than the controls (0.12 vs. 0.27 per person year); cumulative 1-year survival was 91% among program patient and 76% among the control patients. Readmission, and hospital days per 100 person-days was higher for the program patients (0.36 vs. 0.17 per person year), and (2.19 vs. 1.88 per person year) respectively. Conclusions Participation in “DMP” was associated with lower all-cause mortality when compared to the controls. This survival gain in the program patients was paradoxically associated with an increase in readmission rate and total hospital days. PMID:27499955

Video-Based Fingerprint Verification

PubMed Central

Qin, Wei; Yin, Yilong; Liu, Lili

2013-01-01

Conventional fingerprint verification systems use only static information. In this paper, fingerprint videos, which contain dynamic information, are utilized for verification. Fingerprint videos are acquired by the same capture device that acquires conventional fingerprint images, and the user experience of providing a fingerprint video is the same as that of providing a single impression. After preprocessing and aligning processes, “inside similarity” and “outside similarity” are defined and calculated to take advantage of both dynamic and static information contained in fingerprint videos. Match scores between two matching fingerprint videos are then calculated by combining the two kinds of similarity. Experimental results show that the proposed video-based method leads to a relative reduction of 60 percent in the equal error rate (EER) in comparison to the conventional single impression-based method. We also analyze the time complexity of our method when different combinations of strategies are used. Our method still outperforms the conventional method, even if both methods have the same time complexity. Finally, experimental results demonstrate that the proposed video-based method can lead to better accuracy than the multiple impressions fusion method, and the proposed method has a much lower false acceptance rate (FAR) when the false rejection rate (FRR) is quite low. PMID:24008283

Designing a Score-Based Method for the Evaluation of the Nutritional Quality of the Gluten-Free Bakery Products and their Gluten-Containing Counterparts.

PubMed

Morreale, Federico; Angelino, Donato; Pellegrini, Nicoletta

2018-04-25

Gluten-free (GF) products are consumed both by individuals with celiac disease and by an increasing number of people with no specific medical needs. Although the technological quality of GF products has been recently improved, their nutritional quality is still scarcely addressed. Moreover, the few published studies report conflicting results, mostly because the information from product nutrition facts is the only considered factor. The aim of the present study was to develop a score-based method for the nutritional evaluation of 134 packaged Italian GF bakery products and to compare it with that of 162 matched gluten-containing (GC) food items. The score included the information from the nutrition facts and the presence/absence of some nutritionally relevant components in the ingredients list. Results indicated an overall low nutritional quality of the considered GF bakery products. Additionally, with the sole exception of GF bread substitutes, there was no difference in nutritional quality between GF and equivalent GC bakery products. Future research and development of GF bakery products may take advantage of this scoring method, as it may represent an easy approach to evaluate their nutritional quality. The present findings do not justify the consumption of packaged GF bakery products by people without any specific medical needs.

Video feedback promotes relations between infants and vulnerable first-time mothers: a quasi-experimental study.

PubMed

Kristensen, Ingeborg Hedegaard; Simonsen, Marianne; Trillingsgaard, Tea; Kronborg, Hanne

2017-11-15

Supporting early mother-infant relationships to ensure infants' future health has been recommended. The aim of this study was to investigate whether video feedback using the Marte Meo method promotes a healthy early relationship between infants and vulnerable first-time mothers. Video feedback or usual care was delivered by health visitors during home visits in Danish municipalities. This quasi-experimental study included pre- and post-tests of 278 vulnerable families. Mothers were allocated to an intervention group (n = 69), a comparison group (n = 209) and an exactly matched video subsample from the comparison group (n = 63). Data consisted of self-reported questionnaires and video recordings of mother-infant interactions. Outcomes were mother-infant dyadic synchrony (CARE-Index), maternal confidence (KPCS), parental stress (PSS), maternal mood (EPDS) and infant socialemotional behaviours (ASQ:SE). The data were analysed using descriptive and linear multiple regression analysis. The levels of dyadic synchrony in the intervention group had significantly improved (p < 0.001) at follow-up with a mean score of 9.51 (95%CI;8.93-10.09) compared with 7.62 (95%CI;7.03-8.21). The intervention group also showed a higher level of maternal sensitivity with a mean score of 9.55 (95%CI;8.96-10.14) compared with 7.83 (95%CI;7.19-8.46) in the matched video subsample (p < 0.001). With respect to infant cooperation, similar improvements were found with a mean score of 9.43 (95% CI;8.88-9.99) in the intervention group compared with 7.73 (95%CI;7.13-8.33) in the matched video subsample from the comparison group (p < 0.001). Furthermore, mothers in the intervention group reported significantly lower levels of parental stress with a mean score of 32.04 (95%CI;30.13-33.94) compared with 35.29 (95%CI;34.07-36.52) in the comparison group (p = 0.03), as well as higher levels of maternal confidence with a mean score of 41.10 (95%CI;40.22-41.98) compared with 40.10 (95%CI;39.65-40.56) in the comparison group (p = 0.04). No significant differences were found in EPDS and ASQ:SE. The findings support the assumption that video feedback using the Marte Meo method early after birth may strengthen the relationship between infants and vulnerable firsttime mothers as well as improve maternal psychosocial functioning. Further research applying random assignment is needed to strengthen these conclusions; further research is also needed to assess any long term effects of the video feedback intervention using the Marte Meo method. This study was registered on 24 January 2013 in ClinicalTrials.gov with the identifier: NCT01799447 .

Gender Differences in the Learning Status of Diabetic Children.

ERIC Educational Resources Information Center

Holmes, Clarissa S.; And Others

1992-01-01

Evaluated learning status of 95 diabetic children and 97 matched controls. Results indicated that diabetic boys had significantly lower Freedom from Distractibility scores compared with scores of diabetic girls and controls, and lower Perceptual Organization scores compared with scores of control boys. Diabetic children experienced more learning…

Quantifying the quality of hand movement in stroke patients through three-dimensional curvature

PubMed Central

2011-01-01

Background To more accurately evaluate rehabilitation outcomes in stroke patients, movement irregularities should be quantified. Previous work in stroke patients has revealed a reduction in the trajectory smoothness and segmentation of continuous movements. Clinically, the Stroke Impairment Assessment Set (SIAS) evaluates the clumsiness of arm movements using an ordinal scale based on the examiner's observations. In this study, we focused on three-dimensional curvature of hand trajectory to quantify movement, and aimed to establish a novel measurement that is independent of movement duration. We compared the proposed measurement with the SIAS score and the jerk measure representing temporal smoothness. Methods Sixteen stroke patients with SIAS upper limb proximal motor function (Knee-Mouth test) scores ranging from 2 (incomplete performance) to 4 (mild clumsiness) were recruited. Nine healthy participant with a SIAS score of 5 (normal) also participated. Participants were asked to grasp a plastic glass and repetitively move it from the lap to the mouth and back at a conformable speed for 30 s, during which the hand movement was measured using OPTOTRAK. The position data was numerically differentiated and the three-dimensional curvature was computed. To compare against a previously proposed measure, the mean squared jerk normalized by its minimum value was computed. Age-matched healthy participants were instructed to move the glass at three different movement speeds. Results There was an inverse relationship between the curvature of the movement trajectory and the patient's SIAS score. The median of the -log of curvature (MedianLC) correlated well with the SIAS score, upper extremity subsection of Fugl-Meyer Assessment, and the jerk measure in the paretic arm. When the healthy participants moved slowly, the increase in the jerk measure was comparable to the paretic movements with a SIAS score of 2 to 4, while the MedianLC was distinguishable from paretic movements. Conclusions Measurement based on curvature was able to quantify movement irregularities and matched well with the examiner's observations. The results suggest that the quality of paretic movements is well characterized using spatial smoothness represented by curvature. The smaller computational costs associated with this measurement suggest that this method has potential clinical utility. PMID:22040326

An Analysis of Surgical Treatment for the Spontaneous Rupture of Hepatocellular Carcinoma.

PubMed

Sada, Haruki; Ohira, Masahiro; Kobayashi, Tsuyoshi; Tashiro, Hirotaka; Chayama, Kazuaki; Ohdan, Hideki

2016-01-01

The prognosis of spontaneous rupture of hepatocellular carcinoma (HCC) remains unclear. We investigated the prognosis of patients with ruptured HCC based on the treatments and prognostic factors associated with long-term survival. The prognoses of 64 consecutive patients treated for ruptured HCC from 1986 to 2013 were analyzed according to their methods of treatment. The prognostic factors of 16 surgical patients were identified, and their overall survival (OS) and recurrence rates were compared to 1,157 surgical patients who underwent surgery for non-ruptured HCC. The surgical outcomes were also compared using a propensity score matching method. Surgery was associated with a better OS. Curative resection was the only independent prognostic factor in surgical patients with ruptured HCC (p = 0.040). Although the OS of surgical patients with non-ruptured HCC was found to be significantly better than that of the patients with ruptured HCC, no significant difference in OS was observed after propensity score matching. A curative resection should be the objective of treatment, assuming the suitability of the patient's clinical condition. When the liver function reserve and tumor extension of patients with ruptured and non-ruptured HCC are similar, then their surgical outcomes may not be significantly different. © 2015 S. Karger AG, Basel.

Mass spectrometry-based protein identification by integrating de novo sequencing with database searching.

PubMed

Wang, Penghao; Wilson, Susan R

2013-01-01

Mass spectrometry-based protein identification is a very challenging task. The main identification approaches include de novo sequencing and database searching. Both approaches have shortcomings, so an integrative approach has been developed. The integrative approach firstly infers partial peptide sequences, known as tags, directly from tandem spectra through de novo sequencing, and then puts these sequences into a database search to see if a close peptide match can be found. However the current implementation of this integrative approach has several limitations. Firstly, simplistic de novo sequencing is applied and only very short sequence tags are used. Secondly, most integrative methods apply an algorithm similar to BLAST to search for exact sequence matches and do not accommodate sequence errors well. Thirdly, by applying these methods the integrated de novo sequencing makes a limited contribution to the scoring model which is still largely based on database searching. We have developed a new integrative protein identification method which can integrate de novo sequencing more efficiently into database searching. Evaluated on large real datasets, our method outperforms popular identification methods.

13 CFR 130.450 - Matching funds.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Matching Funds of the recipient organization: (1) Uncompensated student labor; (2) SCORE, ACE, or SBI volunteers; (3) Program income or fees collected from small businesses receiving assistance; (4) Funds or...

13 CFR 130.450 - Matching funds.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Matching Funds of the recipient organization: (1) Uncompensated student labor; (2) SCORE, ACE, or SBI volunteers; (3) Program income or fees collected from small businesses receiving assistance; (4) Funds or...

13 CFR 130.450 - Matching funds.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Matching Funds of the recipient organization: (1) Uncompensated student labor; (2) SCORE, ACE, or SBI volunteers; (3) Program income or fees collected from small businesses receiving assistance; (4) Funds or...

13 CFR 130.450 - Matching funds.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Matching Funds of the recipient organization: (1) Uncompensated student labor; (2) SCORE, ACE, or SBI volunteers; (3) Program income or fees collected from small businesses receiving assistance; (4) Funds or...

Application of new WAIS-III/WMS-III discrepancy scores for evaluating memory functioning: relationship between intellectual and memory ability.

PubMed

Lange, Rael T; Chelune, Gordon J

2006-05-01

Analysis of the discrepancy between memory and intellectual ability has received some support as a means for evaluating memory impairment. Recently, comprehensive base rate tables for General Ability Index (GAI) minus memory discrepancy scores (i.e., GAI-memory) were developed using the WAIS-III/WMS-III standardization sample (Lange, Chelune, & Tulsky, in press). The purpose of this study was to evaluate the clinical utility of GAI-memory discrepancy scores to identify memory impairment in 34 patients with Alzheimer's type dementia (DAT) versus a sample of 34 demographically matched healthy participants. On average, patients with DAT obtained significantly lower scores on all WAIS-III and WMS-III indexes and had larger GAI-memory discrepancy scores. Clinical outcome analyses revealed that GAI-memory scores were useful at identifying memory impairment in patients with DAT versus matched healthy participants. However, GAI-memory discrepancy scores failed to provide unique interpretive information beyond that which is gained from the memory indexes alone. Implications and future research directions are discussed.

Methodological approaches in analysing observational data: A practical example on how to address clustering and selection bias.

PubMed

Trutschel, Diana; Palm, Rebecca; Holle, Bernhard; Simon, Michael

2017-11-01

Because not every scientific question on effectiveness can be answered with randomised controlled trials, research methods that minimise bias in observational studies are required. Two major concerns influence the internal validity of effect estimates: selection bias and clustering. Hence, to reduce the bias of the effect estimates, more sophisticated statistical methods are needed. To introduce statistical approaches such as propensity score matching and mixed models into representative real-world analysis and to conduct the implementation in statistical software R to reproduce the results. Additionally, the implementation in R is presented to allow the results to be reproduced. We perform a two-level analytic strategy to address the problems of bias and clustering: (i) generalised models with different abilities to adjust for dependencies are used to analyse binary data and (ii) the genetic matching and covariate adjustment methods are used to adjust for selection bias. Hence, we analyse the data from two population samples, the sample produced by the matching method and the full sample. The different analysis methods in this article present different results but still point in the same direction. In our example, the estimate of the probability of receiving a case conference is higher in the treatment group than in the control group. Both strategies, genetic matching and covariate adjustment, have their limitations but complement each other to provide the whole picture. The statistical approaches were feasible for reducing bias but were nevertheless limited by the sample used. For each study and obtained sample, the pros and cons of the different methods have to be weighted. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Sparse Feature Extraction for Pose-Tolerant Face Recognition.

PubMed

Abiantun, Ramzi; Prabhu, Utsav; Savvides, Marios

2014-10-01

Automatic face recognition performance has been steadily improving over years of research, however it remains significantly affected by a number of factors such as illumination, pose, expression, resolution and other factors that can impact matching scores. The focus of this paper is the pose problem which remains largely overlooked in most real-world applications. Specifically, we focus on one-to-one matching scenarios where a query face image of a random pose is matched against a set of gallery images. We propose a method that relies on two fundamental components: (a) A 3D modeling step to geometrically correct the viewpoint of the face. For this purpose, we extend a recent technique for efficient synthesis of 3D face models called 3D Generic Elastic Model. (b) A sparse feature extraction step using subspace modeling and ℓ1-minimization to induce pose-tolerance in coefficient space. This in return enables the synthesis of an equivalent frontal-looking face, which can be used towards recognition. We show significant performance improvements in verification rates compared to commercial matchers, and also demonstrate the resilience of the proposed method with respect to degrading input quality. We find that the proposed technique is able to match non-frontal images to other non-frontal images of varying angles.

Visualising fragrances through colours: the mediating role of emotions.

PubMed

Schifferstein, Hendrik N J; Tanudjaja, Inge

2004-01-01

To facilitate communication about fragrances, one can use the colours people tend to associate with their smells. We investigated to what extent odour-colour correspondences for fine fragrances can be accounted for by underlying emotional associations. Odour-colour matches and degree-of-fit judgments revealed that odours were matched to colours non-randomly. Matching colours differed mainly on blackness (brightness), and less on chromaticness (saturation) and hue. Furthermore, we found a consistent negative relationship between odour-colour degree-of-fit ratings and the difference between the odour scores and the colour scores on one of the emotion dimensions (pleasure). This suggests that emotional associations may partly underlie odour-colour correspondences.

Sex differences in physics learning and evaluations in an introductory course

NASA Astrophysics Data System (ADS)

Blue, Jennifer Marie

On a national level, boys and men score higher than girls and women on science and math tests. There have been several investigations into the reasons for these differences, with some believing that they are caused by innate biological sex differences and some that they are caused by social and cultural gender differences. In addition, women who plan to major in science and engineering drop out of those majors at higher rates than men do. This study was designed to contribute to the ongoing discussion about why these differences between women and men exist. This study compared post-test physics scores of a matched sample of men and women to see whether there were differences in how much physics had been learned at the end of a course when there were few differences at the beginning of the course. The study also looked at the ratings that men and women gave to the problem solving method and the sections of the course that used cooperative grouping. It was found that, although the population of students taking Physics 1251 showed differences in performance on physics tests both at the beginning and at the end of the course, when students were matched according to their high school background and their physics pretest scores there was no difference in their post-test scores. It was also found that women liked the relevant aspects of the course more than men did. Implications of these results are discussed.

Assessing the short term impact of air pollution on mortality: a matching approach.

PubMed

Baccini, Michela; Mattei, Alessandra; Mealli, Fabrizia; Bertazzi, Pier Alberto; Carugno, Michele

2017-02-10

The opportunity to assess short term impact of air pollution relies on the causal interpretation of the exposure-response association. However, up to now few studies explicitly faced this issue within a causal inference framework. In this paper, we reformulated the problem of assessing the short term impact of air pollution on health using the potential outcome approach to causal inference. We considered the impact of high daily levels of particulate matter ≤10 μm in diameter (PM 10 ) on mortality within two days from the exposure in the metropolitan area of Milan (Italy), during the period 2003-2006. Our research focus was the causal impact of a hypothetical intervention setting daily air pollution levels under a pre-fixed threshold. We applied a matching procedure based on propensity score to estimate the total number of attributable deaths (AD) during the study period. After defining the number of attributable deaths in terms of difference between potential outcomes, we used the estimated propensity score to match each high exposure day, namely each day with a level of exposure higher than 40 μg/m 3 , with a day with similar background characteristics but a level of exposure lower than 40 μg/m 3 . Then, we estimated the impact by comparing mortality between matched days. During the study period daily exposures larger than 40 μg/m 3 were responsible for 1079 deaths (90% CI: 116; 2042). The impact was more evident among the elderly than in the younger age classes. Exposures ≥ 40 μg/m 3 were responsible, among the elderly, for 1102 deaths (90% CI: 388, 1816), of which 797 from cardiovascular causes and 243 from respiratory causes. Clear evidence of an impact on respiratory mortality was found also in the age class 65-74, with 87 AD (90% CI: 11, 163). The propensity score matching turned out to be an appealing method to assess historical impacts in this field, which guarantees that the estimated total number of AD can be derived directly as sum of either age-specific or cause-specific AD, unlike the standard model-based procedure. For this reason, it is a promising approach to perform surveillance focusing on very specific causes of death or diseases, or on susceptible subpopulations. Finally, the propensity score matching is free from issues concerning the exposure-confounders-mortality modeling and does not involve extrapolation. On the one hand this enhances the internal validity of our results; on the other, it makes the approach scarcely appropriate for estimating future impacts.

Improving Spoken Language Outcomes for Children With Hearing Loss: Data-driven Instruction.

PubMed

Douglas, Michael

2016-02-01

To assess the effects of data-driven instruction (DDI) on spoken language outcomes of children with cochlear implants and hearing aids. Retrospective, matched-pairs comparison of post-treatment speech/language data of children who did and did not receive DDI. Private, spoken-language preschool for children with hearing loss. Eleven matched pairs of children with cochlear implants who attended the same spoken language preschool. Groups were matched for age of hearing device fitting, time in the program, degree of predevice fitting hearing loss, sex, and age at testing. Daily informal language samples were collected and analyzed over a 2-year period, per preschool protocol. Annual informal and formal spoken language assessments in articulation, vocabulary, and omnibus language were administered at the end of three time intervals: baseline, end of year one, and end of year two. The primary outcome measures were total raw score performance of spontaneous utterance sentence types and syntax element use as measured by the Teacher Assessment of Spoken Language (TASL). In addition, standardized assessments (the Clinical Evaluation of Language Fundamentals--Preschool Version 2 (CELF-P2), the Expressive One-Word Picture Vocabulary Test (EOWPVT), the Receptive One-Word Picture Vocabulary Test (ROWPVT), and the Goldman-Fristoe Test of Articulation 2 (GFTA2)) were also administered and compared with the control group. The DDI group demonstrated significantly higher raw scores on the TASL each year of the study. The DDI group also achieved statistically significant higher scores for total language on the CELF-P and expressive vocabulary on the EOWPVT, but not for articulation nor receptive vocabulary. Post-hoc assessment revealed that 78% of the students in the DDI group achieved scores in the average range compared with 59% in the control group. The preliminary results of this study support further investigation regarding DDI to investigate whether this method can consistently and significantly improve the achievement of children with hearing loss in spoken language skills.

Hand grip strength and chronic obstructive pulmonary disease in Korea: an analysis in KNHANES VI.

PubMed

Lee, Su Hwan; Kim, Soo Jung; Han, Yeji; Ryu, Yon Ju; Lee, Jin Hwa; Chang, Jung Hyun

2017-01-01

Muscle mass is known to be associated with mortality in elderly adults. Because hand grip strength (HGS) is known as a simple assessment tool for muscular strength, many researchers have studied the association between HGS and disease. However, empirical evidence for the relationship between chronic obstructive pulmonary disease (COPD) and HGS is still controversial. The aim of this study was to evaluate the association between COPD and HGS, using Korean population data. This was a population-based cross-sectional study. Data were obtained from the sixth Korean National Health and Nutrition Examination Survey, which was conducted from 2013 to 2015. To reduce the effects of HGS-related factors and potential confounding factors, propensity score matching was used to match subjects with and without COPD. Among 14,930 subjects, 832 were enrolled in each group (non-COPD and COPD) after propensity score matching. COPD subjects did not have lower HGS than non-COPD subjects (non-COPD vs COPD, male, 38.0±7.0 vs 38.9±7.0 kg, P =0.044, female, 23.8±4.6 vs 24.2±4.9 kg, P =0.342). Lung function was classified by Global Initiative for Chronic Obstructive Lung Disease stages and was not significantly associated with HGS. For male COPD subjects, there was a significant correlation between HGS and the EuroQol Five-Dimension Questionnaire (EQ5D) utility score index, which is an indicator of quality of life that adjusts for age and body mass index ( r =0.201, P <0.001). The correlation was absent for female subjects ( r =0.098, P =0.170). COPD subjects did not have lower HGS than non-COPD subjects. HGS did not associate with lung function. However, the HGS of male COPD subjects was positively associated with EQ5D utility score index, an indicator of quality of life. HGS may be helpful as an additional method to the evaluation of quality of life in male COPD patients.

The effects of police contact on trajectories of violence: a group-based, propensity score matching analysis.

PubMed

Ward, Jeffrey T; Krohn, Marvin D; Gibson, Chris L

2014-02-01

This study uses a life course framework to investigate how police contacts may serve as a potential turning point in a violent crime trajectory. Drawing on the central ideas from deterrence and labeling theories, we determine whether individuals on different violent offending trajectories increase or decrease their offending following a police contact. Analyzing nine waves of data from the Rochester Youth Development Study, an integrated propensity score matching and latent class growth model was used. First, three violent trajectory groups emerged including high offenders, non-offenders, and low offenders. Second, after accounting for selection bias using propensity score matching procedures, experiencing a police contact increased the likelihood of future violent offending for the entire sample and for those who were on a low violent-offending trajectory specifically. These findings are interpreted as partial support for labeling theory. Limitations of the study and directions for future research are discussed.

Changing recruitment outcomes: the 'why' and the 'how'.

PubMed

MacLean, Lisa; Pato, Michèle T

2011-01-01

Residency programs compete for applicants and commit extensive resources to the recruitment process. After failing to fill in the match for 5 years (1999-2004), this program decided to make changes in its recruitment process. The authors describe one program's experience in improving recruitment outcomes. The new training director surveyed other program directors, reviewed medical student feedback, and evaluated previous recruitment processes, developing and implementing a new plan. Tracked outcome measures included USMLE scores, COMLEX scores, match results, and American graduate ratios. After implementation of the new process in 2004-2005, the program has filled all six positions every year. Average median COMLEX 1 and 2 scores increased from 35.0 to 77.5 (p<0.012). The American graduate-to-International medical graduate ratio (AMG/IMG ratio) for the program changed from 7/16 in 1999 to 19/5 for Years 2006-2009. Changes in the recruitment process can favorably alter match outcomes.

Self-reported hand washing behaviors and foodborne illness: a propensity score matching approach.

PubMed

Ali, Mir M; Verrill, Linda; Zhang, Yuanting

2014-03-01

Hand washing is a simple and effective but easily overlooked way to reduce cross-contamination and the transmission of foodborne pathogens. In this study, we used the propensity score matching methodology to account for potential selection bias to explore our hypothesis that always washing hands before food preparation tasks is associated with a reduction in the probability of reported foodborne illness. Propensity score matching can simulate random assignment to a condition so that pretreatment observable differences between a treatment group and a control group are homogenous on all the covariates except the treatment variable. Using the U.S. Food and Drug Administration's 2010 Food Safety Survey, we estimated the effect of self-reported hand washing behavior on the probability of self-reported foodborne illness. Our results indicate that reported washing of hands with soap always before food preparation leads to a reduction in the probability of reported foodborne illness.

Effect of Chronic Diseases on Work Productivity: A Propensity Score Analysis.

PubMed

Fouad, Ahmed Mahmoud; Waheed, Amani; Gamal, Amira; Amer, Shaimaa Ahmed; Abdellah, Rasha Farouk; Shebl, Fatma Mohamed

2017-05-01

The aim of this study was to evaluate the effect of chronic disease(s) on work productivity. Using the Health & Work Performance Questionnaire, information was collected from 516 workers on chronic disease status and work productivity. Propensity-score matching was performed to identify matched-pairs of workers. In the propensity-score matched sample, workers with chronic diseases were more likely to have increased absenteeism and presenteeism rates, 6.34 and 2.36 times the rates if no chronic diseases, respectively. In addition, they had greater odds for getting negative critical work incidents and less odds for positive incidents than none or balanced status. Multimorbidity showed more significant increase in absenteeism and presenteeism rates, as well as increased odds for excess negative critical work incidents. Chronic disease(s) can significantly reduce work productivity by increasing absenteeism, presenteeism, and net negative critical incidents.

Within-Cluster and Across-Cluster Matching with Observational Multilevel Data

ERIC Educational Resources Information Center

Kim, Jee-Seon; Steiner, Peter M.; Hall, Courtney; Thoemmes, Felix

2013-01-01

When randomized experiments cannot be conducted in practice, propensity score (PS) techniques for matching treated and control units are frequently used for estimating causal treatment effects from observational data. Despite the popularity of PS techniques, they are not yet well studied for matching multilevel data where selection into treatment…

Face matching impairment in developmental prosopagnosia.

PubMed

White, David; Rivolta, Davide; Burton, A Mike; Al-Janabi, Shahd; Palermo, Romina

2017-02-01

Developmental prosopagnosia (DP) is commonly referred to as 'face blindness', a term that implies a perceptual basis to the condition. However, DP presents as a deficit in face recognition and is diagnosed using memory-based tasks. Here, we test face identification ability in six people with DP, who are severely impaired on face memory tasks, using tasks that do not rely on memory. First, we compared DP to control participants on a standardized test of unfamiliar face matching using facial images taken on the same day and under standardized studio conditions (Glasgow Face Matching Test; GFMT). Scores for DP participants did not differ from normative accuracy scores on the GFMT. Second, we tested face matching performance on a test created using images that were sourced from the Internet and so varied substantially due to changes in viewing conditions and in a person's appearance (Local Heroes Test; LHT). DP participants showed significantly poorer matching accuracy on the LHT than control participants, for both unfamiliar and familiar face matching. Interestingly, this deficit is specific to 'match' trials, suggesting that people with DP may have particular difficulty in matching images of the same person that contain natural day-to-day variations in appearance. We discuss these results in the broader context of individual differences in face matching ability.

Evaluation of accuracy of shade selection using two spectrophotometer systems: Vita Easyshade and Degudent Shadepilot.

PubMed

Kalantari, Mohammad Hassan; Ghoraishian, Seyed Ahmad; Mohaghegh, Mina

2017-01-01

The aim of this in vitro study was to evaluate the accuracy of shade matching using two spectrophotometric devices. Thirteen patients who require a full coverage restoration for one of their maxillary central incisors were selected while the adjacent central incisor was intact. 3 same frameworks were constructed for each tooth using computer-aided design and computer-aided manufacturing technology. Shade matching was performed using Vita Easyshade spectrophotometer, Shadepilot spectrophotometer, and Vitapan classical shade guide for the first, second, and third crown subsequently. After application, firing, and glazing of the porcelain, the color was evaluated and scored by five inspectors. Both spectrophotometric systems showed significantly better results than visual method ( P < 0.05) while there were no significant differences between Vita Easyshade and Shadepilot spectrophotometers ( P < 0.05). Spectrophotometers are a good substitute for visual color selection methods.

HHsvm: fast and accurate classification of profile–profile matches identified by HHsearch

PubMed Central

Dlakić, Mensur

2009-01-01

Motivation: Recently developed profile–profile methods rival structural comparisons in their ability to detect homology between distantly related proteins. Despite this tremendous progress, many genuine relationships between protein families cannot be recognized as comparisons of their profiles result in scores that are statistically insignificant. Results: Using known evolutionary relationships among protein superfamilies in SCOP database, support vector machines were trained on four sets of discriminatory features derived from the output of HHsearch. Upon validation, it was shown that the automatic classification of all profile–profile matches was superior to fixed threshold-based annotation in terms of sensitivity and specificity. The effectiveness of this approach was demonstrated by annotating several domains of unknown function from the Pfam database. Availability: Programs and scripts implementing the methods described in this manuscript are freely available from http://hhsvm.dlakiclab.org/. Contact: mdlakic@montana.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19773335

Starting Dose of Sorafenib for the Treatment of Hepatocellular Carcinoma: A Retrospective, Multi-Institutional Study.

PubMed

Reiss, Kim A; Yu, Shun; Mamtani, Ronac; Mehta, Rajni; D'Addeo, Kathryn; Wileyto, E Paul; Taddei, Tamar H; Kaplan, David E

2017-11-01

Purpose Sorafenib is currently the only Food and Drug Administration-approved first-line therapy for patients with advanced hepatocellular carcinoma. There are few data examining how sorafenib starting dose may influence patient outcomes and costs. Patients and Methods We retrospectively evaluated 4,903 patients from 128 Veterans Health Administration hospitals who were prescribed sorafenib for hepatocellular carcinoma between January 2006 and April 2015. After 1:1 propensity score matching to account for potential treatment bias, hazard ratios (HRs) were calculated using Cox regression and were tested against a noninferiority margin of HR = 1.1. A matched multivariate logistic regression was performed to adjust for potential confounders. The primary end point was overall survival (OS) of patients who were prescribed standard starting dosage sorafenib (800 mg/d per os) versus that of patients who were prescribed reduced starting dose sorafenib (< 800 mg/d per os). Results There were 3,094 standard dose sorafenib patients (63%) and 1,809 reduced starting dose sorafenib patients (37%). Reduced starting dose sorafenib patients had more Barcelona Clinic Liver Cancer stage D ( P < .001), higher Model for End-Stage Liver Disease Sodium scores ( P < .001), higher Child-Turcotte-Pugh scores ( P < .001), and higher Cirrhosis Comorbidity Index scores ( P = .01). Consequently, reduced starting dose sorafenib patients had lower OS (median, 200 v 233 days, HR = 1.10). After propensity score matching and adjusting for potential confounders, there was no longer a significant OS difference (adjusted hazard ratio [HR adj ], 0.92; 95% CI, 0.83 to 1.01), and this fell significantly below the noninferiority margin ( P < .001). Reduced starting dose sorafenib patients experienced significantly lower total cumulative sorafenib cost and were less likely to discontinue sorafenib because of gastrointestinal adverse effects (8.7% v 10.8%; P = .047). Conclusion The initiation of sorafenib therapy at reduced dosages was associated with reduced pill burden, reduced treatment costs, and a trend toward a decreased rate of discontinuing sorafenib because of adverse events. Reduced dosing was not associated with inferior OS relative to standard dosing.

HLA AND CROSS·REACTIVE ANTIGEN GROUP MATCHING FOR CADAVER KIDNEY ALLOCATION1

PubMed Central

Starzl, Thomas E.; Eliasziw, Michael; Gjertson, David; Terasaki, Paul I.; Fung, John J.; Trucco, Massimo; Martell, Joan; McMichael, John; Scantlebury, Velma; Shapiro, Ron; Donner, Allan

2010-01-01

Background Allocation of cadaver kidneys by graded human leukocyte antigen (HLA) compatibility scoring arguably has had little effect on overall survival while prejudicing the transplant candidacy of African-American and other hard to match populations. Consequently, matching has been proposed of deduced amino acid residues of the individual HLA molecules shared by cross-reactive antigen groups (CREGs). We have examined the circumstances under which compatibility with either method impacted graft survival. Methods Using Cox proportional hazards regression modeling, we studied the relationship between levels of conventional HLA mismatch and other donor and recipient factors on primary cadaver kidney survival between 1981 and 1995 at the University of Pittsburgh (n=1,780) and in the United Network for Organ Sharing (UNOS) Scientific Registry during 1991–1995 (n=31,291). The results were compared with those obtained by the matching of amino acid residues that identified CREG-compatible cases with as many as four (but not five and six) HLA mismatches. Results With more than one HLA mismatch (>85% of patients in both series), most of the survival advantage of a zero mismatch was lost. None of the HLA loci were “weak.” In the UNOS (but not Pittsburgh) category of one-HLA mismatch (n=1334), a subgroup of CREG-matched recipients (35.3%) had better graft survival than the remaining 64.7%, who were CREG-mismatched. There was no advantage of a CREG match in the two- to four-HLA incompatibility tiers. Better graft survival with tacrolimus was observed in both the Pittsburgh and UNOS series. Conclusions Obligatory national sharing of cadaver kidneys is justifiable only for zero-HLA-mismatched kidneys. The potential value of CREG matching observed in the one-HLA-mismatched recipients of the UNOS (but not the Pittsburgh) experience deserves further study. PMID:9381546

Quantifying the causal effects of 20mph zones on road casualties in London via doubly robust estimation.

PubMed

Li, Haojie; Graham, Daniel J

2016-08-01

This paper estimates the causal effect of 20mph zones on road casualties in London. Potential confounders in the key relationship of interest are included within outcome regression and propensity score models, and the models are then combined to form a doubly robust estimator. A total of 234 treated zones and 2844 potential control zones are included in the data sample. The propensity score model is used to select a viable control group which has common support in the covariate distributions. We compare the doubly robust estimates with those obtained using three other methods: inverse probability weighting, regression adjustment, and propensity score matching. The results indicate that 20mph zones have had a significant causal impact on road casualty reduction in both absolute and proportional terms. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of explanations on mathematical reasoning tasks

NASA Astrophysics Data System (ADS)

Norqvist, Mathias

2018-01-01

Studies in mathematics education often point to the necessity for students to engage in more cognitively demanding activities than just solving tasks by applying given solution methods. Previous studies have shown that students that engage in creative mathematically founded reasoning to construct a solution method, perform significantly better in follow up tests than students that are given a solution method and engage in algorithmic reasoning. However, teachers and textbooks, at least occasionally, provide explanations together with an algorithmic method, and this could possibly be more efficient than creative reasoning. In this study, three matched groups practiced with either creative, algorithmic, or explained algorithmic tasks. The main finding was that students that practiced with creative tasks did, outperform the students that practiced with explained algorithmic tasks in a post-test, despite a much lower practice score. The two groups that got a solution method presented, performed similarly in both practice and post-test, even though one group got an explanation to the given solution method. Additionally, there were some differences between the groups in which variables predicted the post-test score.

Match Duration and Number of Rallies in Men’s and Women’s 2000–2010 FIVB World Tour Beach Volleyball

PubMed Central

Palao, José Manuel; Valades, David; Ortega, Enrique

2012-01-01

After the 2000 Olympic Games, the Fédération Internationale de Volleyball (FIVB) modified the scoring system used in beach volleyball from side-out to a rally point system. The goal was to facilitate the comprehension of the game and to stabilize match duration. The purpose of this study was to assess the duration and number of rallies in men’s and women’s beach volleyball matches (2000–2010 FIVB World Tour). Data from 14,432 men’s matches and 14,175 women’s matches of the 2000–2010 World Tour were collected. The variables studied were: match duration, total rallies per set and match, number of sets, team that won the set and match, type of match (equality in score), and gender. The average match duration in beach volleyball is stable, ranging from 30 to 64 minutes, regardless of the number of sets, the stage of the tournament (qualifying round or main draw), or gender. The average number of rallies per match were 78–80 for two-set matches and 94–96 for three-set matches. Matches from the main draw are more balanced than matches from the qualifying round. More balanced matches (smaller point difference between teams) have longer durations. It is not clear why there is no relationship between the number of rallies and match duration. Future studies are needed to clarify this aspect. The results can serve as a reference to guide beach volleyball training (with regard to duration and number of rallies) and to help understand the effect of the rule change. PMID:23486703

Do observational studies using propensity score methods agree with randomized trials? A systematic comparison of studies on acute coronary syndromes

PubMed Central

Dahabreh, Issa J.; Sheldrick, Radley C.; Paulus, Jessica K.; Chung, Mei; Varvarigou, Vasileia; Jafri, Haseeb; Rassen, Jeremy A.; Trikalinos, Thomas A.; Kitsios, Georgios D.

2012-01-01

Aims Randomized controlled trials (RCTs) are the gold standard for assessing the efficacy of therapeutic interventions because randomization protects from biases inherent in observational studies. Propensity score (PS) methods, proposed as a potential solution to confounding of the treatment–outcome association, are widely used in observational studies of therapeutic interventions for acute coronary syndromes (ACS). We aimed to systematically assess agreement between observational studies using PS methods and RCTs on therapeutic interventions for ACS. Methods and results We searched for observational studies of interventions for ACS that used PS methods to estimate treatment effects on short- or long-term mortality. Using a standardized algorithm, we matched observational studies to RCTs based on patients’ characteristics, interventions, and outcomes (‘topics’), and we compared estimates of treatment effect between the two designs. When multiple observational studies or RCTs were identified for the same topic, we performed a meta-analysis and used the summary relative risk for comparisons. We matched 21 observational studies investigating 17 distinct clinical topics to 63 RCTs (median = 3 RCTs per observational study) for short-term (7 topics) and long-term (10 topics) mortality. Estimates from PS analyses differed statistically significantly from randomized evidence in two instances; however, observational studies reported more extreme beneficial treatment effects compared with RCTs in 13 of 17 instances (P = 0.049). Sensitivity analyses limited to large RCTs, and using alternative meta-analysis models yielded similar results. Conclusion For the treatment of ACS, observational studies using PS methods produce treatment effect estimates that are of more extreme magnitude compared with those from RCTs, although the differences are rarely statistically significant. PMID:22711757

Reconstruction based finger-knuckle-print verification with score level adaptive binary fusion.

PubMed

Gao, Guangwei; Zhang, Lei; Yang, Jian; Zhang, Lin; Zhang, David

2013-12-01

Recently, a new biometrics identifier, namely finger knuckle print (FKP), has been proposed for personal authentication with very interesting results. One of the advantages of FKP verification lies in its user friendliness in data collection. However, the user flexibility in positioning fingers also leads to a certain degree of pose variations in the collected query FKP images. The widely used Gabor filtering based competitive coding scheme is sensitive to such variations, resulting in many false rejections. We propose to alleviate this problem by reconstructing the query sample with a dictionary learned from the template samples in the gallery set. The reconstructed FKP image can reduce much the enlarged matching distance caused by finger pose variations; however, both the intra-class and inter-class distances will be reduced. We then propose a score level adaptive binary fusion rule to adaptively fuse the matching distances before and after reconstruction, aiming to reduce the false rejections without increasing much the false acceptances. Experimental results on the benchmark PolyU FKP database show that the proposed method significantly improves the FKP verification accuracy.

Employment during pregnancy and obstetric intervention without medical reason: labor induction and cesarean delivery

PubMed Central

Kozhimannil, Katy Backes; Attanasio, Laura B.; Johnson, Pamela Jo; Gjerdingen, Dwenda K.; McGovern, Patricia M.

2014-01-01

Background Rising rates of labor induction and cesarean delivery, especially when used without a medical reason, have generated concern among clinicians, women, and policymakers. Whether employment status affects pregnant women's childbirth-related care is not known. We estimated the relationship between prenatal employment and obstetric procedures, distinguishing whether women reported that the induction or cesarean was performed for medical reasons. Methods Using data from a nationally-representative sample of women who gave birth in U.S. hospitals (N=1,573), we used propensity score matching to reduce potential bias from non-random selection into employment. Outcomes were cesarean delivery and labor induction, with and without a self-reported medical reason. Exposure was prenatal employment status (full-time employment, not employed). We conducted separate analyses for unmatched and matched cohorts using multivariable regression models. Findings There were no differences in labor induction based on employment status. In unmatched analyses, employed women had higher odds of cesarean delivery overall (adjusted odds ratio (AOR) = 1.45, p=0.046) and cesarean delivery without medical reason (AOR=1.94, p=0.024). Adding an interaction term between employment and college education revealed no significant effects on cesarean without medical reason. There were no significant differences in cesarean delivery by employment status in the propensity score matched analysis. Conclusions Full-time prenatal employment is associated with higher odds of cesarean delivery, but this association was not explained by socio-economic status and no longer existed after accounting for socio-demographic differences by matching women employed full-time with similar women not employed during pregnancy. PMID:25213740

Periodontitis and early mortality among adults treated with hemodialysis: a multinational propensity-matched cohort study.

PubMed

Ruospo, Marinella; Palmer, Suetonia C; Wong, Germaine; Craig, Jonathan C; Petruzzi, Massimo; De Benedittis, Michele; Ford, Pauline; Johnson, David W; Tonelli, Marcello; Natale, Patrizia; Saglimbene, Valeria; Pellegrini, Fabio; Celia, Eduardo; Gelfman, Ruben; Leal, Miguel R; Torok, Marietta; Stroumza, Paul; Bednarek-Skublewska, Anna; Dulawa, Jan; Frantzen, Luc; Del Castillo, Domingo; Schon, Staffan; Bernat, Amparo G; Hegbrant, Jorgen; Wollheim, Charlotta; Gargano, Letizia; Bots, Casper P; Strippoli, Giovanni Fm

2017-05-22

Periodontitis is associated with cardiovascular mortality in the general population and adults with chronic diseases. However, it is unclear whether periodontitis predicts survival in the setting of kidney failure. ORAL-D was a propensity matched analysis in 3338 dentate adults with end-stage kidney disease treated in a hemodialysis network in Europe and South America designed to examine the association between periodontitis and all-cause and cardiovascular-related mortality in people on long-term hemodialysis. Participants were matched 1:1 on their propensity score for moderate to severe periodontitis assessed using the World Health Organization Community Periodontal Index. A random-effects Cox proportional hazards model was fitted with shared frailty to account for clustering of mortality risk within countries. Among the 3338 dentate participants, 1355 (40.6%) had moderate to severe periodontitis at baseline. After using propensity score methods to generate a matched cohort of participants with periodontitis similar to those with none or mild periodontal disease, moderate to severe periodontitis was associated with a lower risk of all-cause (9.1 versus 13.0 per 100 person years, hazard ratio 0.74, 95% confidence interval 0.61 to 0.90) and cardiovascular (4.3 versus 6.9 per 100 person years, hazard ratio 0.67, 0.51 to 0.88) mortality. These associations were not changed substantially when participants were limited to those with 12 or more natural teeth and when accounting for competing causes of cardiovascular death. In contrast to the general population, periodontitis does not appear to be associated with an increased risk of early death in adults treated with hemodialysis.

Two food-assisted maternal and child health nutrition programs helped mitigate the impact of economic hardship on child stunting in Haiti.

PubMed

Donegan, Shannon; Maluccio, John A; Myers, Caitlin K; Menon, Purnima; Ruel, Marie T; Habicht, Jean-Pierre

2010-06-01

Rigorous evaluations of food-assisted maternal and child health and nutrition programs are stymied by the ethics of randomizing recipients to a control treatment. Using nonexperimental matching methods, we evaluated the effect of 2 such programs on child linear growth in Haiti. The 2 well-implemented programs offered the same services (food assistance, behavior change communication, and preventive health services) to pregnant and lactating women and young children. They differed in that one (the preventive program) used blanket targeting of all children 6-23 mo, whereas the other (the recuperative program) targeted underweight (weight-for-age Z score < -2) children 6-59 mo, as traditionally done. We estimated program effects on height-for-age Z scores (HAZ) and stunting (HAZ < -2) by comparing outcomes of children in program areas with matched children from comparable populations in the Haiti Demographic and Health Survey. Children 12-41 mo in the preventive and recuperative program areas had lower prevalence of stunting than those in the matched control group [16 percentage points (pp) lower in preventive and 11 pp in recuperative]. Children in the 2 program areas also were more likely than those in the matched control group to be breast-fed up to 24 mo (25 pp higher in preventive, 22 in recuperative) and children 12 mo and older were more likely to have received the recommended full schedule of vaccinations (32 pp higher in preventive, 31 in recuperative). Both programs improved targeted behaviors and protected child growth in a time of deteriorating economic circumstances.

Mediastinal micro-vessels clipping during lymph node dissection may contribute to reduce postoperative pleural drainage

PubMed Central

Yan, Shi; Wang, Xing; Lv, Chao; Phan, Kevin; Wang, Yuzhao; Wang, Jia; Yang, Yue

2016-01-01

Background Postoperative pleural drainage markedly influences the length of postoperative stay and financial costs of medical care. The aim of this study is to retrospectively investigate potentially predisposing factors related to pleural drainage after curative thoracic surgery and to explore the impact of mediastinal micro-vessels clipping on pleural drainage control after lymph node dissection. Methods From February 2012 to November 2013, 322 consecutive cases of operable non-small cell lung cancers (NSCLC) undergoing lobectomy and mediastinal lymph node dissection with or without application of clipping were collected. Total and daily postoperative pleural drainage were recorded. Propensity score matching (1:2) was applied to balance variables potentially impacting pleural drainage between group clip and group control. Analyses were performed to compare drainage volume, duration of chest tube and postoperative hospital stay between the two groups. Variables linked with pleural drainage in whole cohort were assessed using multivariable logistic regression analysis. Results Propensity score matching resulted in 197 patients (matched cohort). Baseline patient characteristics were matched between two groups. Group clip showed less cumulative drainage volume (P=0.020), shorter duration of chest tube (P=0.031) and postoperative hospital stay (P=0.022) compared with group control. Risk factors significantly associated with high-output drainage in multivariable logistic regression analysis were being male, age >60 years, bilobectomy/sleeve lobectomy, pleural adhesion, the application of clip applier, duration of operation ≥220 minutes and chylothorax (P<0.05). Conclusions This study suggests that mediastinal micro-vessels clipping during lymph node dissection may reduce postoperative pleural drainage and thus shorten hospital stay. PMID:27076936

Puzzling Findings in Studying the Outcome of “Real World” Adolescent Mental Health Services: The TRAILS Study

PubMed Central

Jörg, Frederike; Ormel, Johan; Reijneveld, Sijmen A.; Jansen, Daniëlle E. M. C.; Verhulst, Frank C.; Oldehinkel, Albertine J.

2012-01-01

Background The increased use and costs of specialist child and adolescent mental health services (MHS) urge us to assess the effectiveness of these services. The aim of this paper is to compare the course of emotional and behavioural problems in adolescents with and without MHS use in a naturalistic setting. Method and Findings Participants are 2230 (pre)adolescents that enrolled in a prospective cohort study, the TRacking Adolescents' Individual Lives Survey (TRAILS). Response rate was 76%, mean age at baseline 11.09 (SD 0.56), 50.8% girls. We used data from the first three assessment waves, covering a six year period. Multiple linear regression analysis, propensity score matching, and data validation were used to compare the course of emotional and behavioural problems of adolescents with and without MHS use. The association between MHS and follow-up problem score (β 0.20, SE 0.03, p-value<0.001) was not confounded by baseline severity, markers of adolescent vulnerability or resilience nor stressful life events. The propensity score matching strategy revealed that follow-up problem scores of non-MHS-users decreased while the problem scores of MHS users remained high. When taking into account future MHS (non)use, it appeared that problem scores decreased with limited MHS use, albeit not as much as without any MHS use, and that problem scores with continuous MHS use remained high. Data validation showed that using a different outcome measure, multiple assessment waves and multiple imputation of missing values did not alter the results. A limitation of the study is that, although we know what type of MHS participants used, and during which period, we lack information on the duration of the treatment. Conclusions The benefits of MHS are questionable. Replication studies should reveal whether a critical examination of everyday care is necessary or an artefact is responsible for these results. PMID:23028584

On the use and misuse of scalar scores of confounders in design and analysis of observational studies.

PubMed

Pfeiffer, R M; Riedl, R

2015-08-15

We assess the asymptotic bias of estimates of exposure effects conditional on covariates when summary scores of confounders, instead of the confounders themselves, are used to analyze observational data. First, we study regression models for cohort data that are adjusted for summary scores. Second, we derive the asymptotic bias for case-control studies when cases and controls are matched on a summary score, and then analyzed either using conditional logistic regression or by unconditional logistic regression adjusted for the summary score. Two scores, the propensity score (PS) and the disease risk score (DRS) are studied in detail. For cohort analysis, when regression models are adjusted for the PS, the estimated conditional treatment effect is unbiased only for linear models, or at the null for non-linear models. Adjustment of cohort data for DRS yields unbiased estimates only for linear regression; all other estimates of exposure effects are biased. Matching cases and controls on DRS and analyzing them using conditional logistic regression yields unbiased estimates of exposure effect, whereas adjusting for the DRS in unconditional logistic regression yields biased estimates, even under the null hypothesis of no association. Matching cases and controls on the PS yield unbiased estimates only under the null for both conditional and unconditional logistic regression, adjusted for the PS. We study the bias for various confounding scenarios and compare our asymptotic results with those from simulations with limited sample sizes. To create realistic correlations among multiple confounders, we also based simulations on a real dataset. Copyright © 2015 John Wiley & Sons, Ltd.

Impact of caring for persons with Alzheimer's disease or dementia on caregivers' health outcomes: findings from a community based survey in Japan.

PubMed

Goren, Amir; Montgomery, William; Kahle-Wrobleski, Kristin; Nakamura, Tomomi; Ueda, Kaname

2016-06-10

This study assessed how family caregivers for patients with Alzheimer's disease (AD) or dementia in Japan differed from non-caregivers in characteristics and health outcomes (i.e., comorbidities, health-related quality of life [HRQoL], productivity, and resource use). Caregivers were hypothesized to experience significantly poorer outcomes than non-caregivers. Data were combined from the 2012 and 2013 National Health and Wellness Survey in Japan (n = 60000). Caregivers for adult relatives with AD or dementia were compared with non-caregivers on: comorbidities (including Patient Health Questionnaire (PHQ-9) cutoff scores suggesting presence/absence of major depressive disorder (MDD)), Work Productivity and Activity Impairment (WPAI), SF-36v2-based HRQoL, and healthcare resource utilization. Sociodemographic characteristics, health characteristics and behaviors, and Charlson comorbidity index (CCI) scores were compared across groups. Propensity matching, based on scores generated from a logistic regression predicting caregiving, was used to match caregivers with non-caregivers with similar likelihood of being caregivers. Bivariate comparisons across matched groups served to estimate outcomes differences due to caregiving. Among 55060 respondents, compared with non-caregivers (n = 53758), caregivers (n = 1302) were older (52.6 vs. 47.5 years), more frequently female (53 % vs. 49 %), married/partnered, frequent alcohol drinkers, current smokers, exercisers, and not employed, and they averaged higher CCI scores (0.37 vs. 0.14), all p < 0.05. Propensity scores incorporated sex, age, body mass index (BMI), exercise, alcohol, smoking, marital status, CCI, insured status, education, employment, income, and children in household. A greedy matching algorithm produced 1297 exact matches, excluding 5 non-matched caregivers. Health utilities scores were significantly lower among caregivers (0.724) vs. non-caregivers (0.764), as were SF-36v2 Physical and Mental Component Summary scores. Caregivers vs. non-caregivers had significantly higher absenteeism, presenteeism-related impairment, overall work impairment (25.8 % vs. 20.4 %, respectively), and activity impairment (25.4 % vs. 21.8 %), more emergency room and traditional provider visits (7.70 vs. 5.35) in the past six months, and more frequent MDD (14 % vs. 9 %), depression, insomnia, anxiety, and pain. Those providing care for patients with AD or dementia in Japan experienced significantly poorer HRQoL and greater comorbid risk, productivity impairment, and resource use. These findings inform the need for greater support for caregivers and their patients.

Deformed Palmprint Matching Based on Stable Regions.

PubMed

Wu, Xiangqian; Zhao, Qiushi

2015-12-01

Palmprint recognition (PR) is an effective technology for personal recognition. A main problem, which deteriorates the performance of PR, is the deformations of palmprint images. This problem becomes more severe on contactless occasions, in which images are acquired without any guiding mechanisms, and hence critically limits the applications of PR. To solve the deformation problems, in this paper, a model for non-linearly deformed palmprint matching is derived by approximating non-linear deformed palmprint images with piecewise-linear deformed stable regions. Based on this model, a novel approach for deformed palmprint matching, named key point-based block growing (KPBG), is proposed. In KPBG, an iterative M-estimator sample consensus algorithm based on scale invariant feature transform features is devised to compute piecewise-linear transformations to approximate the non-linear deformations of palmprints, and then, the stable regions complying with the linear transformations are decided using a block growing algorithm. Palmprint feature extraction and matching are performed over these stable regions to compute matching scores for decision. Experiments on several public palmprint databases show that the proposed models and the KPBG approach can effectively solve the deformation problem in palmprint verification and outperform the state-of-the-art methods.

A comparison of the validity of the five-factor model (FFM) personality disorder prototypes. Using FFM self-report and interview measures.

PubMed

Miller, Joshua D; Bagby, R Michael; Pilkonis, Paul A

2005-12-01

Recent studies have demonstrated that personality disorders (PDs) can be assessed via a prototype-matching technique, which enables researchers and clinicians to match an individual's five-factor model (FFM) personality profile to an expert-generated prototype. The current study examined the relations between these prototype scores, using interview and self-report data, and PD symptoms in an outpatient sample (N = 115). Both sets of PD prototype scores demonstrated significant convergent validity with PD symptom counts, suggesting that the FFM PD prototype scores are appropriate for use with both sources of data.

Matching health information seekers' queries to medical terms

PubMed Central

2012-01-01

Background The Internet is a major source of health information but most seekers are not familiar with medical vocabularies. Hence, their searches fail due to bad query formulation. Several methods have been proposed to improve information retrieval: query expansion, syntactic and semantic techniques or knowledge-based methods. However, it would be useful to clean those queries which are misspelled. In this paper, we propose a simple yet efficient method in order to correct misspellings of queries submitted by health information seekers to a medical online search tool. Methods In addition to query normalizations and exact phonetic term matching, we tested two approximate string comparators: the similarity score function of Stoilos and the normalized Levenshtein edit distance. We propose here to combine them to increase the number of matched medical terms in French. We first took a sample of query logs to determine the thresholds and processing times. In the second run, at a greater scale we tested different combinations of query normalizations before or after misspelling correction with the retained thresholds in the first run. Results According to the total number of suggestions (around 163, the number of the first sample of queries), at a threshold comparator score of 0.3, the normalized Levenshtein edit distance gave the highest F-Measure (88.15%) and at a threshold comparator score of 0.7, the Stoilos function gave the highest F-Measure (84.31%). By combining Levenshtein and Stoilos, the highest F-Measure (80.28%) is obtained with 0.2 and 0.7 thresholds respectively. However, queries are composed by several terms that may be combination of medical terms. The process of query normalization and segmentation is thus required. The highest F-Measure (64.18%) is obtained when this process is realized before spelling-correction. Conclusions Despite the widely known high performance of the normalized edit distance of Levenshtein, we show in this paper that its combination with the Stoilos algorithm improved the results for misspelling correction of user queries. Accuracy is improved by combining spelling, phoneme-based information and string normalizations and segmentations into medical terms. These encouraging results have enabled the integration of this method into two projects funded by the French National Research Agency-Technologies for Health Care. The first aims to facilitate the coding process of clinical free texts contained in Electronic Health Records and discharge summaries, whereas the second aims at improving information retrieval through Electronic Health Records. PMID:23095521

Prehospital Helicopter Transport and Survival of Patients With Traumatic Brain Injury

PubMed Central

Mackenzie, Todd A.

2015-01-01

Objective To investigate the association of helicopter transport with survival of patients with traumatic brain injury (TBI), in comparison with ground emergency medical services (EMS). Background Helicopter utilization and its effect on the outcomes of TBI remain controversial. Methods We performed a retrospective cohort study involving patients with TBI who were registered in the National Trauma Data Bank between 2009 and 2011. Regression techniques with propensity score matching were used to investigate the association of helicopter transport with survival of patients with TBI, in comparison with ground EMS. Results During the study period, there were 209,529 patients with TBI who were registered in the National Trauma Data Bank and met the inclusion criteria. Of these patients, 35,334 were transported via helicopters and 174,195 via ground EMS. For patients transported to level I trauma centers, 2797 deaths (12%) were recorded after helicopter transport and 8161 (7.8%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival [OR (odds ratio), 1.95; 95% confidence interval (CI), 1.81–2.10; absolute risk reduction (ARR), 6.37%]. This persisted after propensity score matching (OR, 1.88; 95% CI, 1.74–2.03; ARR, 5.93%). For patients transported to level II trauma centers, 1282 deaths (10.6%) were recorded after helicopter transport and 5097 (7.3%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival (OR, 1.81; 95% CI, 1.64–2.00; ARR 5.17%). This again persisted after propensity score matching (OR, 1.73; 95% CI, 1.55–1.94; ARR, 4.69). Conclusions Helicopter transport of patients with TBI to level I and II trauma centers was associated with improved survival, in comparison with ground EMS. PMID:24743624

Attributable Cost of Clostridium difficile Infection in Pediatric Patients.

PubMed

Mehrotra, Preeti; Jang, Jisun; Gidengil, Courtney; Sandora, Thomas J

2017-12-01

OBJECTIVES The attributable cost of Clostridium difficile infection (CDI) in children is unknown. We sought to determine a national estimate of attributable cost and length of stay (LOS) of CDI occurring during hospitalization in children. DESIGN AND METHODS We analyzed discharge records of patients between 2 and 18 years of age from the Agency for Healthcare Research and Quality (AHRQ) Kids' Inpatient Database. We created a logistic regression model to predict CDI during hospitalization based on demographic and clinical characteristics. Predicted probabilities from the logistic regression model were then used as propensity scores to match 1:2 CDI to non-CDI cases. Charges were converted to costs and compared between patients with CDI and propensity-score-matched controls. In a sensitivity analysis, we adjusted for LOS as a confounder by including it in both the propensity score and a generalized linear model predicting cost. RESULTS We identified 8,527 pediatric hospitalizations (0.53%) with a diagnosis of CDI and 1,597,513 discharges without CDI. In our matched cohorts, the attributable cost of CDI occurring during a hospitalization ranged from $1,917 to $8,317, depending on whether model was adjusted for LOS. When not adjusting for LOS, CDI-associated hospitalizations cost 1.6 times more than non-CDI associated hospitalizations. Attributable LOS of CDI was approximately 4 days. CONCLUSIONS Clostridium difficile infection in hospitalized children is associated with an economic burden similar to adult estimates. This finding supports a continued focus on preventing CDI in children as a priority. Pediatric CDI cost analyses should account for LOS as an important confounder of cost. Infect Control Hosp Epidemiol 2017;38:1472-1477.

Reduced 30-day mortality in men after elective coronary artery bypass surgery with minimized extracorporeal circulation-a propensity score analysis

PubMed Central

2012-01-01

Background Impact of minimized extracorporeal circulation (MECC) for coronary surgery on mortality remains controversial and gender significantly influence outcome. Methods We analyzed 3,139 male patients undergoing elective coronary surgery between 01/2004 and 05/2009. Using propensity score matching after binary logistic regression, 1,005 patients (from 1,119 patients) undergoing surgery with MECC could be matched with 1,005 patients (from 2,020 patients) undergoing surgery with conventional extracorporeal circulation (CECC). Primary outcome was 30-day mortality. Results Unadjusted 30-day mortality was 2.7% in patients with CECC and 0.8% in those with MECC (mean difference -1.9%; p < 0.001). The adjusted mean difference (average treatment effect of the treated) after matching was -1.5% (95% confidence interval (CI) -2.6 to -0.4; p = 0.006). Postoperative hospital stay was shorter in patients operated with minimized systems (adjusted mean difference -0.8 days; 95% CI -1.46 to -0.09; p = 0.03) and incidence of postoperative neurocognitive dysfunction was also lower (adjusted mean difference -1.3%; 95% CI -2.2 to -0.4; p = 0.001). Chest tube drainage (adjusted mean difference +22 mL; 95% CI -47 to 91; p = 0.5) and risk for acute kidney injury, kidney injury and failure according to RIFLE criteria (adjusted mean difference -1.0%; 95% CI -2.5 to 0.6; p = 0.24) proved to be insignificant between both groups. Apart from reduced 30-day mortality, however, average treatment effects for intensive care unit stay, postoperative hospital stay, chest tube drainage and kidney injury did not significantly differ. Conclusion Using propensity score analysis, we observed an association between MECC and reduced 30-day mortality in men, but our results call for further analysis. PMID:22424497

Reference values for the creatine kinase response to professional Australian football match-play.

PubMed

Inman, Luke A G; Rennie, Michael J; Watsford, Mark L; Gibbs, Nathan J; Green, James; Spurrs, Robert W

2018-08-01

Due to the importance of monitoring markers of muscle damage in high-level sport from a medical and athlete recovery perspective, this study aimed to determine the upper limits of normal (ULN) for post-match plasma creatine kinase (CK) in professional Australian footballers. Raw CK values were considered, along with intra-individual deviations from the season-mean. Case series. CK was collected between 36-48h following professional Australian football match-play. A total of 1565 samples from 62 players were assessed over three consecutive seasons. The ULN were determined for raw scores and as a percentage of each player's season-mean response. The ULN for raw CK, as determined by the 97.5th, 95th and 90th percentiles were 1715 (90%CI: 1605-1890), 1380 (90%CI: 1325-1475) and 1110 (90%CI: 1050-1170) UL -1 respectively. The ULN intra-individual response (97.5th percentile) was defined as a player's score being greater than 94% (90%CI: 84-102%) above their season-mean. Professional Australian football elicits a profound effect on the CK response. The values provide a reference tool for athletes competing at this level of competition. The novel method of representing the CK response as a percentage difference from an individuals' season-mean enables a superior comparative ability between CK responses and reduces the high CK responder bias that occurs when using raw scores alone. The data will assist medical and conditioning staff in excluding medical emergencies and also aid in individualising the prescription of training loads and recovery to optimise athlete performance and minimise further muscle damage. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Parent Involvement in the Pediatric Resident Applicant Interview.

PubMed

Dandekar, Abhay; Weintraub, Miranda L Ritterman; McFeely, Eric D; Chasnovitz, Rebecca

2018-03-19

Parents and patients are actively involved in the clinical learning environment, yet scant literature exists about their involvement in the residency interview process. We aimed to pilot a process of including parents in resident interviews and to determine its value. During the 2016-17 residency interview cycle, 22 parent volunteers, blinded to applicant credentials, conducted brief structured interviews with 118 applicants. We then surveyed all parents and applicants with the use of mixed methods: descriptive statistics to analyze 5-point Likert-type-scale responses, and content analysis to identify themes from open-ended questions. Although parent interviews were not used in ranking, we later compared final composite parent interview scores (1-10, with 10 being high) among the final rank and match list candidates. Response rates were high for both groups (parents 100%; resident applicants 98.3%). Parents felt strongly positive about meeting applicants (mean ± SD, 5.00 ± 0.00), the value of parent participation (4.90 ± 0.30), and their own experience (4.95 ± 0.22). Applicants felt positive about meeting parents (4.45 ± 0.70), the value of parent participation (3.92 ± 0.84), and their own experience (4.51 ± 0.67). Several themes emerged from both groups, with the most salient parent themes including the value of patient-centered perspectives and appreciation and joy of meeting applicants. Parent interview scores correlated with the final match list, with matched applicants scoring higher (9.08 vs 8.51; P = .05). Involvement of parents in the pediatric residency interview process is achievable, is perceived positively by parents and applicants, and may provide valuable perspectives for consideration in residency selection. Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Household Financial Management and Women's Experiences of Intimate Partner Violence in the Philippines: A Study Using Propensity Score Methods.

PubMed

Tsai, Laura Cordisco

2016-04-27

This study explores the causal impact of independent management of household finances upon women's experiences of intimate partner violence (IPV) in the Philippines. Propensity score matching is used to generate a casual estimate of the impact of women's roles as household financial managers on their experiences of IPV. Findings demonstrate that managing household finances independently significantly increased the severity of IPV women experienced from their partners compared with women who managed finances jointly with partners. Findings reinforce the importance of explicit attention to intrahousehold power dynamics and gender norms in the implementation of microfinance interventions intended to empower women. © The Author(s) 2016.

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients

PubMed Central

Habel, Laurel A; Shak, Steven; Jacobs, Marlena K; Capra, Angela; Alexander, Claire; Pho, Mylan; Baker, Joffre; Walker, Michael; Watson, Drew; Hackett, James; Blick, Noelle T; Greenberg, Deborah; Fehrenbacher, Louis; Langholz, Bryan; Quesenberry, Charles P

2006-01-01

Introduction The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community hospital setting. Methods A case-control study was conducted among 4,964 Kaiser Permanente patients diagnosed with node-negative invasive breast cancer from 1985 to 1994 and not treated with adjuvant chemotherapy. Cases (n = 220) were patients who died from breast cancer. Controls (n = 570) were breast cancer patients who were individually matched to cases with respect to age, race, adjuvant tamoxifen, medical facility and diagnosis year, and were alive at the date of death of their matched case. Using an RT-PCR assay, archived tumor tissues were analyzed for expression levels of 16 cancer-related and five reference genes, and a summary risk score (the Recurrence Score) was calculated for each patient. Conditional logistic regression methods were used to estimate the association between risk of breast cancer death and Recurrence Score. Results After adjusting for tumor size and grade, the Recurrence Score was associated with risk of breast cancer death in ER-positive, tamoxifen-treated and -untreated patients (P = 0.003 and P = 0.03, respectively). At 10 years, the risks for breast cancer death in ER-positive, tamoxifen-treated patients were 2.8% (95% confidence interval [CI] 1.7–3.9%), 10.7% (95% CI 6.3–14.9%), and 15.5% (95% CI 7.6–22.8%) for those in the low, intermediate and high risk Recurrence Score groups, respectively. They were 6.2% (95% CI 4.5–7.9%), 17.8% (95% CI 11.8–23.3%), and 19.9% (95% CI 14.2–25.2%) for ER-positive patients not treated with tamoxifen. In both the tamoxifen-treated and -untreated groups, approximately 50% of patients had low risk Recurrence Score values. Conclusion In this large, population-based study of lymph node-negative patients not treated with chemotherapy, the Recurrence Score was strongly associated with risk of breast cancer death among ER-positive, tamoxifen-treated and -untreated patients. PMID:16737553

FIEFDom: A Transparent Domain Boundary Recognition System using a Fuzzy Mean Operator

DTIC Science & Technology

2008-12-04

to search for matching fragments by running the PSI-BLAST program a second time. During this step, the expectation value threshold ( e -value) is set at...statistical significance (or low e -value), and therefore have low scores. Finally, the domain boundaries (if any) are predicted using the scored...neighbor (match) is weighted by its e -value, the relative contribution of each neighbor is apparent. This is contrary to black-box models in which the

Propensity score models in observational comparative effectiveness studies: cornerstone of design or statistical afterthought?

PubMed

Robinson, John W

2012-03-01

Propensity score models are increasingly used in observational comparative effectiveness studies to reduce confounding by covariates that are associated with both a study outcome and treatment choice. Any such potentially confounding covariate will bias estimation of the effect of treatment on the outcome, unless the distribution of that covariate is well-balanced between treatment and control groups. Constructing a subsample of treated and control subjects who are matched on estimated propensity scores is a means of achieving such balance for covariates that are included in the propensity score model. If, during study design, investigators assemble a comprehensive inventory of known and suspected potentially confounding covariates, examination of how well this inventory is covered by the chosen dataset yields an assessment of the extent of bias reduction that is possible by matching on estimated propensity scores. These considerations are explored by examining the designs of three recently published comparative effectiveness studies.

Longer-term Baerveldt to Trabectome glaucoma surgery comparison using propensity score matching.

PubMed

Kostanyan, Tigran; Shazly, Tarek; Kaplowitz, Kevin B; Wang, Steven Z; Kola, Sushma; Brown, Eric N; Loewen, Nils A

2017-12-01

To apply propensity score matching to compare Baerveldt glaucoma drainage implant (BGI) to Trabectome-mediated ab interno trabeculectomy (AIT). Recent data suggests that AIT can produce results similar to BGI which is traditionally reserved for more severe glaucoma. BGI and AIT patients with at least 1 year of follow-up were included. The primary outcome measures were intraocular pressure (IOP), number of glaucoma medications, and a Glaucoma Index (GI) score. GI reflected glaucoma severity based on visual field, the number of preoperative medications, and preoperative IOP. Score matching used a genetic algorithm consisting of age, gender, type of glaucoma, concurrent phacoemulsification, baseline number of medications, and baseline IOP. Patients with neovascular glaucoma, with prior glaucoma surgery, or without a close match were excluded. Of 353 patients, 30 AIT patients were matched to 29 BGI patients. Baseline characteristics including, IOP, the number of glaucoma medications, type of glaucoma, the degree of VF loss and GI were not significantly different between AIT and BGI. BGI had a preoperative IOP of 21.6 ± 6.3 mmHg compared to 21.5 ± 7.4 for AIT on 2.8 ± 1.1 medications and 2.5 ± 2.3 respectively. At 30 months, the mean IOP was 15.0 ± 3.9 mmHg for AIT versus 15.0 ± 5.7 mmHg for BGI (p > 0.05), while the number of drops was 1.5 ± 1.3 for AIT (change: p = 0.001) versus 2.4 ± 1.2 for BGI (change: p = 0.17; AIT vs BGI: 0.007). Success, defined as IOP < 21 mmHg, < 20% reduction and no reoperation, was achieved at 1 year in 56% of AIT versus 55% of BGI (p > 0.05) and 50% versus 52% at 2.5 years. A propensity score matched comparison of AIT and BGI demonstrated a similar IOP reduction through 1 year. AIT required fewer medications.

Fixture congestion modulates post-match recovery kinetics in professional soccer players.

PubMed

Lundberg, Tommy R; Weckström, Kristoffer

2017-01-01

This study examined the influence of fixture congestion on physical performance and biochemical variables in professional male footballers. After 3 competitive matches within a week (3M cycle), 16 players underwent blood sampling and field testing 72 h after the last match. The same tests were performed after a regular 1 match-week cycle (1M cycle). The 1M vs. 3M change scores were compared between Congested (high match exposure) and non-selected Control players. The change score in muscle soreness was greater (effect size 1.0; CI 0.0-1.9) in the Congested players than Controls, indicating a possible negative effect of fixture congestion. There were no effects on sprint and jump performance. The change in plasma (P)-Urea was greater in Congested players than controls (effect size 1.3; CI 0.3-2.2). The effects on other blood variables were either non-existing/trivial, or unclear. Altogether, physical fitness and immune function were not compromised by match congestion, yet some indices of physiological stress and muscle damage were still evident.

Disaster loss and social media: Can online information increase flood resilience?

NASA Astrophysics Data System (ADS)

Allaire, Maura C.

2016-09-01

When confronted with natural disasters, individuals around the world increasingly use online resources to become informed of forecasted conditions and advisable actions. This study tests the effectiveness of online information and social media in enabling households to reduce disaster losses. The 2011 Bangkok flood is utilized as a case study since it was one of the first major disasters to affect a substantial population connected to social media. The role of online information is investigated with a mixed methods approach. Both quantitative (propensity score matching) and qualitative (in-depth interviews) techniques are employed. The study relies on two data sources—survey responses from 469 Bangkok households and in-depth interviews with internet users who were a subset of the survey participants. Propensity score matching indicates that social media enabled households to reduce flood losses by an average of 37% (USD 3708 per household), using a nearest neighbor estimator. This reduction is substantial when considering that household flood losses for the matched sample averaged USD 8278. Social media offered information not available from other sources, such as localized and nearly real-time updates of flood location and depth. With this knowledge, households could move belongings to higher ground before floodwaters arrived. These findings suggest that utilizing social media users as sensors could better inform populations during disasters. Overall, the study reveals that online information can enable effective disaster preparedness and reduce losses.

Football goal distributions and extremal statistics

NASA Astrophysics Data System (ADS)

Greenhough, J.; Birch, P. C.; Chapman, S. C.; Rowlands, G.

2002-12-01

We analyse the distributions of the number of goals scored by home teams, away teams, and the total scored in the match, in domestic football games from 169 countries between 1999 and 2001. The probability density functions (PDFs) of goals scored are too heavy-tailed to be fitted over their entire ranges by Poisson or negative binomial distributions which would be expected for uncorrelated processes. Log-normal distributions cannot include zero scores and here we find that the PDFs are consistent with those arising from extremal statistics. In addition, we show that it is sufficient to model English top division and FA Cup matches in the seasons of 1970/71-2000/01 on Poisson or negative binomial distributions, as reported in analyses of earlier seasons, and that these are not consistent with extremal statistics.

Measuring the impact of Hurricane Katrina on access to a personal healthcare provider: the use of the National Survey of Children's Health for an external comparison group.

PubMed

Stehling-Ariza, Tasha; Park, Yoon Soo; Sury, Jonathan J; Abramson, David

2012-04-01

This paper examined the effect of Hurricane Katrina on children's access to personal healthcare providers and evaluated the use of propensity score methods to compare a nationally representative sample of children, as a proxy for an unexposed group, with a smaller exposed sample. 2007 data from the Gulf Coast Child and Family Health (G-CAFH) Study, a longitudinal cohort of households displaced or greatly impacted by Hurricane Katrina, were matched with 2007 National Survey of Children's Health (NSCH) data using propensity score techniques. Propensity scores were created using poverty level, household educational attainment, and race/ethnicity, with and without the addition of child age and gender. The outcome was defined as having a personal healthcare provider. Additional confounders (household structure, neighborhood safety, health and insurance status) were also examined. All covariates except gender differed significantly between the exposed (G-CAFH) and unexposed (NSCH) samples. Fewer G-CAFH children had a personal healthcare provider (65 %) compared to those from NSCH (90 %). Adjusting for all covariates, the propensity score analysis showed exposed children were 20 % less likely to have a personal healthcare provider compared to unexposed children in the US (OR = 0.80, 95 % CI 0.76, 0.84), whereas the logistic regression analysis estimated a stronger effect (OR = 0.28, 95 % CI 0.21, 0.39). Two years after Hurricane Katrina, children exposed to the storm had significantly lower odds of having a personal health care provider compared to unexposed children. Propensity score matching techniques may be useful for combining separate data samples when no clear unexposed group exists.

Measuring decision quality: psychometric evaluation of a new instrument for breast cancer surgery

PubMed Central

2012-01-01

Background The purpose of this paper is to examine the acceptability, feasibility, reliability and validity of a new decision quality instrument that assesses the extent to which patients are informed and receive treatments that match their goals. Methods Cross-sectional mail survey of recent breast cancer survivors, providers and healthy controls and a retest survey of survivors. The decision quality instrument includes knowledge questions and a set of goals, and results in two scores: a breast cancer surgery knowledge score and a concordance score, which reflects the percentage of patients who received treatments that match their goals. Hypotheses related to acceptability, feasibility, discriminant validity, content validity, predictive validity and retest reliability of the survey instrument were examined. Results We had responses from 440 eligible patients, 88 providers and 35 healthy controls. The decision quality instrument was feasible to implement in this study, with low missing data. The knowledge score had good retest reliability (intraclass correlation coefficient = 0.70) and discriminated between providers and patients (mean difference 35%, p < 0.001). The majority of providers felt that the knowledge items covered content that was essential for the decision. Five of the 6 treatment goals met targets for content validity. The five goals had moderate to strong retest reliability (0.64 to 0.87). The concordance score was 89%, indicating that a majority had treatments concordant with that predicted by their goals. Patients who had concordant treatment had similar levels of confidence and regret as those who did not. Conclusions The decision quality instrument met the criteria of feasibility, reliability, discriminant and content validity in this sample. Additional research to examine performance of the instrument in prospective studies and more diverse populations is needed. PMID:22681763

A supervised framework for resolving coreference in clinical records.

PubMed

Rink, Bryan; Roberts, Kirk; Harabagiu, Sanda M

2012-01-01

A method for the automatic resolution of coreference between medical concepts in clinical records. A multiple pass sieve approach utilizing support vector machines (SVMs) at each pass was used to resolve coreference. Information such as lexical similarity, recency of a concept mention, synonymy based on Wikipedia redirects, and local lexical context were used to inform the method. Results were evaluated using an unweighted average of MUC, CEAF, and B(3) coreference evaluation metrics. The datasets used in these research experiments were made available through the 2011 i2b2/VA Shared Task on Coreference. The method achieved an average F score of 0.821 on the ODIE dataset, with a precision of 0.802 and a recall of 0.845. These results compare favorably to the best-performing system with a reported F score of 0.827 on the dataset and the median system F score of 0.800 among the eight teams that participated in the 2011 i2b2/VA Shared Task on Coreference. On the i2b2 dataset, the method achieved an average F score of 0.906, with a precision of 0.895 and a recall of 0.918 compared to the best F score of 0.915 and the median of 0.859 among the 16 participating teams. Post hoc analysis revealed significant performance degradation on pathology reports. The pathology reports were characterized by complex synonymy and very few patient mentions. The use of several simple lexical matching methods had the most impact on achieving competitive performance on the task of coreference resolution. Moreover, the ability to detect patients in electronic medical records helped to improve coreference resolution more than other linguistic analysis.

Intelligent query by humming system based on score level fusion of multiple classifiers

NASA Astrophysics Data System (ADS)

Pyo Nam, Gi; Thu Trang Luong, Thi; Ha Nam, Hyun; Ryoung Park, Kang; Park, Sung-Joo

2011-12-01

Recently, the necessity for content-based music retrieval that can return results even if a user does not know information such as the title or singer has increased. Query-by-humming (QBH) systems have been introduced to address this need, as they allow the user to simply hum snatches of the tune to find the right song. Even though there have been many studies on QBH, few have combined multiple classifiers based on various fusion methods. Here we propose a new QBH system based on the score level fusion of multiple classifiers. This research is novel in the following three respects: three local classifiers [quantized binary (QB) code-based linear scaling (LS), pitch-based dynamic time warping (DTW), and LS] are employed; local maximum and minimum point-based LS and pitch distribution feature-based LS are used as global classifiers; and the combination of local and global classifiers based on the score level fusion by the PRODUCT rule is used to achieve enhanced matching accuracy. Experimental results with the 2006 MIREX QBSH and 2009 MIR-QBSH corpus databases show that the performance of the proposed method is better than that of single classifier and other fusion methods.

Ranking docking poses by graph matching of protein-ligand interactions: lessons learned from the D3R Grand Challenge 2

NASA Astrophysics Data System (ADS)

da Silva Figueiredo Celestino Gomes, Priscila; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

2018-01-01

A novel docking challenge has been set by the Drug Design Data Resource (D3R) in order to predict the pose and affinity ranking of a set of Farnesoid X receptor (FXR) agonists, prior to the public release of their bound X-ray structures and potencies. In a first phase, 36 agonists were docked to 26 Protein Data Bank (PDB) structures of the FXR receptor, and next rescored using the in-house developed GRIM method. GRIM aligns protein-ligand interaction patterns of docked poses to those of available PDB templates for the target protein, and rescore poses by a graph matching method. In agreement with results obtained during the previous 2015 docking challenge, we clearly show that GRIM rescoring improves the overall quality of top-ranked poses by prioritizing interaction patterns already visited in the PDB. Importantly, this challenge enables us to refine the applicability domain of the method by better defining the conditions of its success. We notably show that rescoring apolar ligands in hydrophobic pockets leads to frequent GRIM failures. In the second phase, 102 FXR agonists were ranked by decreasing affinity according to the Gibbs free energy of the corresponding GRIM-selected poses, computed by the HYDE scoring function. Interestingly, this fast and simple rescoring scheme provided the third most accurate ranking method among 57 contributions. Although the obtained ranking is still unsuitable for hit to lead optimization, the GRIM-HYDE scoring scheme is accurate and fast enough to post-process virtual screening data.

Scoring System Prognostic of Outcome in Patients Undergoing Allogeneic Hematopoietic Cell Transplantation for Myelodysplastic Syndrome.

PubMed

Shaffer, Brian C; Ahn, Kwang Woo; Hu, Zhen-Huan; Nishihori, Taiga; Malone, Adriana K; Valcárcel, David; Grunwald, Michael R; Bacher, Ulrike; Hamilton, Betty; Kharfan-Dabaja, Mohamed A; Saad, Ayman; Cutler, Corey; Warlick, Erica; Reshef, Ran; Wirk, Baldeep Mona; Sabloff, Mitchell; Fasan, Omotayo; Gerds, Aaron; Marks, David; Olsson, Richard; Wood, William Allen; Costa, Luciano J; Miller, Alan M; Cortes, Jorge; Daly, Andrew; Kindwall-Keller, Tamila L; Kamble, Rammurti; Rizzieri, David A; Cahn, Jean-Yves; Gale, Robert Peter; William, Basem; Litzow, Mark; Wiernik, Peter H; Liesveld, Jane; Savani, Bipin N; Vij, Ravi; Ustun, Celalettin; Copelan, Edward; Popat, Uday; Kalaycio, Matt; Maziarz, Richard; Alyea, Edwin; Sobecks, Ron; Pavletic, Steven; Tallman, Martin; Saber, Wael

2016-06-01

To develop a system prognostic of outcome in those undergoing allogeneic hematopoietic cell transplantation (allo HCT) for myelodysplastic syndrome (MDS). We examined 2,133 patients with MDS undergoing HLA-matched (n = 1,728) or -mismatched (n = 405) allo HCT from 2000 to 2012. We used a Cox multivariable model to identify factors prognostic of mortality in a training subset (n = 1,151) of the HLA-matched cohort. A weighted score using these factors was assigned to the remaining patients undergoing HLA-matched allo HCT (validation cohort; n = 577) as well as to patients undergoing HLA-mismatched allo HCT. Blood blasts greater than 3% (hazard ratio [HR], 1.41; 95% CI, 1.08 to 1.85), platelets 50 × 10(9)/L or less at transplantation (HR, 1.37; 95% CI, 1.18 to 1.61), Karnofsky performance status less than 90% (HR, 1.25; 95% CI, 1.06 to 1.28), comprehensive cytogenetic risk score of poor or very poor (HR, 1.43; 95% CI, 1.14 to 1.80), and age 30 to 49 years (HR, 1.60; 95% CI, 1.09 to 2.35) were associated with increased hazard of death and assigned 1 point in the scoring system. Monosomal karyotype (HR, 2.01; 95% CI, 1.65 to 2.45) and age 50 years or older (HR, 1.93; 95% CI, 1.36 to 2.83) were assigned 2 points. The 3-year overall survival after transplantation in patients with low (0 to 1 points), intermediate (2 to 3), high (4 to 5) and very high (≥ 6) scores was 71% (95% CI, 58% to 85%), 49% (95% CI, 42% to 56%), 41% (95% CI, 31% to 51%), and 25% (95% CI, 4% to 46%), respectively (P < .001). Increasing score was predictive of increased relapse (P < .001) and treatment-related mortality (P < .001) in the HLA-matched set and relapse (P < .001) in the HLA-mismatched cohort. The proposed system is prognostic of outcome in patients undergoing HLA-matched and -mismatched allo HCT for MDS. © 2016 by American Society of Clinical Oncology.

Asymptotic Standard Errors of Observed-Score Equating with Polytomous IRT Models

ERIC Educational Resources Information Center

Andersson, Björn

2016-01-01

In observed-score equipercentile equating, the goal is to make scores on two scales or tests measuring the same construct comparable by matching the percentiles of the respective score distributions. If the tests consist of different items with multiple categories for each item, a suitable model for the responses is a polytomous item response…

Dietary pattern analysis: a comparison between matched vegetarian and omnivorous subjects

PubMed Central

2013-01-01

Background Dietary pattern analysis, based on the concept that foods eaten together are as important as a reductive methodology characterized by a single food or nutrient analysis, has emerged as an alternative approach to study the relation between nutrition and disease. The aim of the present study was to compare nutritional intake and the results of dietary pattern analysis in properly matched vegetarian and omnivorous subjects. Methods Vegetarians (n = 69) were recruited via purposeful sampling and matched non-vegetarians (n = 69) with same age, gender, health and lifestyle characteristics were searched for via convenience sampling. Two dietary pattern analysis methods, the Healthy Eating Index-2010 (HEI-2010) and the Mediterranean Diet Score (MDS) were calculated and analysed in function of the nutrient intake. Results Mean total energy intake was comparable between vegetarians and omnivorous subjects (p > 0.05). Macronutrient analysis revealed significant differences between the mean values for vegetarians and omnivorous subjects (absolute and relative protein and total fat intake were significantly lower in vegetarians, while carbohydrate and fibre intakes were significantly higher in vegetarians than in omnivorous subjects). The HEI and MDS were significantly higher for the vegetarians (HEI = 53.8.1 ± 11.2; MDS = 4.3 ± 1.3) compared to the omnivorous subjects (HEI = 46.4 ± 15.3; MDS = 3.8 ± 1.4). Conclusions Our results indicate a more nutrient dense pattern, closer to the current dietary recommendations for the vegetarians compared to the omnivorous subjects. Both indexing systems were able to discriminate between the vegetarians and the non-vegetarians with higher scores for the vegetarian subjects. PMID:23758767

Alcohol Use at Time of Injury and Survival Following Traumatic Brain Injury: Results From the National Trauma Data Bank

PubMed Central

Chen, Chiung M.; Yi, Hsiao-Ye; Yoon, Young-Hee; Dong, Chuanhui

2012-01-01

Objective: Premised on biological evidence from animal research, recent clinical studies have, for the most part, concluded that elevated blood alcohol concentration levels are independently associated with higher survival or decreased mortality in patients with moderate to severe traumatic brain injury (TBI). This study aims to provide some counterevidence to this claim and to further future investigations. Method: Incident data were drawn from the largest U.S. trauma registry, the National Trauma Data Bank, for emergency department admission years 2002–2006. TBI was identified according to the National Trauma Data Bank’s definition using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), codes. To eliminate confounding, the exact matching method was used to match alcohol-positive with alcohol-negative incidents on sex, age, race/ethnicity, and facility. Logistic regression compared in-hospital mortality between 44,043 alcohol-positive and 59,817 matched alcohol-negative TBI incidents, with and without causes and intents of TBI and Injury Severity Score as covariates. A sensitivity analysis was performed within a subsample of isolated moderate to severe TBI incidents. Results: Alcohol use at the time of injury was found to be significantly associated with an increased risk for TBI. Including varied causes and intents of TBI and Injury Severity Score as potential confounders in the regression model explained away the statistical significance of the seemingly protective effect of alcohol against TBI mortality for all TBIs and for isolated moderate to severe TBIs. Conclusions: The null finding shows that the purported reduction in TBI mortality attributed to positive blood alcohol likely is attributable to residual confounding. Accordingly, the risk of TBI associated with alcohol use should not be overlooked. PMID:22630791

Rapid and Robust Cross-Correlation-Based Seismic Phase Identification Using an Approximate Nearest Neighbor Method

NASA Astrophysics Data System (ADS)

Tibi, R.; Young, C. J.; Gonzales, A.; Ballard, S.; Encarnacao, A. V.

2016-12-01

The matched filtering technique involving the cross-correlation of a waveform of interest with archived signals from a template library has proven to be a powerful tool for detecting events in regions with repeating seismicity. However, waveform correlation is computationally expensive, and therefore impractical for large template sets unless dedicated distributed computing hardware and software are used. In this study, we introduce an Approximate Nearest Neighbor (ANN) approach that enables the use of very large template libraries for waveform correlation without requiring a complex distributed computing system. Our method begins with a projection into a reduced dimensionality space based on correlation with a randomized subset of the full template archive. Searching for a specified number of nearest neighbors is accomplished by using randomized K-dimensional trees. We used the approach to search for matches to each of 2700 analyst-reviewed signal detections reported for May 2010 for the IMS station MKAR. The template library in this case consists of a dataset of more than 200,000 analyst-reviewed signal detections for the same station from 2002-2014 (excluding May 2010). Of these signal detections, 60% are teleseismic first P, and 15% regional phases (Pn, Pg, Sn, and Lg). The analyses performed on a standard desktop computer shows that the proposed approach performs the search of the large template libraries about 20 times faster than the standard full linear search, while achieving recall rates greater than 80%, with the recall rate increasing for higher correlation values. To decide whether to confirm a match, we use a hybrid method involving a cluster approach for queries with two or more matches, and correlation score for single matches. Of the signal detections that passed our confirmation process, 52% were teleseismic first P, and 30% were regional phases.

Prediction of significant conduction disease through noninvasive assessment of cardiac calcification.

PubMed

Mainigi, Sumeet K; Chebrolu, Lakshmi Hima Bindu; Romero-Corral, Abel; Mehta, Vinay; Machado, Rodolfo Rozindo; Konecny, Tomas; Pressman, Gregg S

2012-10-01

Cardiac calcification is associated with coronary artery disease, arrhythmias, conduction disease, and adverse cardiac events. Recently, we have described an echocardiographic-based global cardiac calcification scoring system. The objective of this study was to evaluate the severity of cardiac calcification in patients with permanent pacemakers as based on this scoring system. Patients with a pacemaker implanted within the 2-year study period with a previous echocardiogram were identified and underwent blinded global cardiac calcium scoring. These patients were compared to matched control patients without a pacemaker who also underwent calcium scoring. The study group consisted of 49 patients with pacemaker implantation who were compared to 100 matched control patients. The mean calcium score in the pacemaker group was 3.3 ± 2.9 versus 1.8 ± 2.0 (P = 0.006) in the control group. Univariate and multivariate analysis revealed glomerular filtration rate and calcium scoring to be significant predictors of the presence of a pacemaker. Echocardiographic-based calcium scoring correlates with the presence of severe conduction disease requiring a pacemaker. © 2012, Wiley Periodicals, Inc.

Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack.

PubMed

Wong, Adrian; Black, Sandra E; Yiu, Stanley Y P; Au, Lisa W C; Lau, Alexander Y L; Soo, Yannie O Y; Chan, Anne Y Y; Leung, Thomas W H; Wong, Lawrence K S; Kwok, Timothy C Y; Cheung, Theodore C K; Leung, Kam-Tat; Lam, Bonnie Y K; Kwan, Joseph S K; Mok, Vincent C T

2018-05-01

The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy. Copyright © 2018 John Wiley & Sons, Ltd.

Outcome of Intravenous Azithromycin Therapy in Patients with Complicated Scrub Typhus Compared with That of Doxycycline Therapy Using Propensity-Matched Analysis

PubMed Central

Jang, Mi-Ok; Jang, Hee-Chang; Kim, Uh Jin; Ahn, Joon Hwan; Kang, Seung-Ji; Jung, Sook-In; Shin, Hee-Young

2014-01-01

There are no well-matched, controlled studies comparing azithromycin with doxycycline for the treatment of complicated scrub typhus. A retrospective propensity score-matched case-control study was performed for patients who presented with complicated scrub typhus and were treated with doxycycline or azithromycin between 2001 and 2011. Data on comorbidities, clinical manifestations, laboratory studies, treatments, and outcomes were extracted for analysis. The clinical characteristics and outcomes of the azithromycin-treated group (n = 73) were compared to those of the doxycycline-treated group (n = 108). Of 181 patients, 73 from each group were matched by propensity scores. There were no significant differences in baseline characteristics between the matched groups. The treatment success and survival rates were not significantly different (89% [65/73 patients] versus 96% [70/73 patients] and 96% [70/73 patients] versus 96% [70/73 patients], respectively [P > 0.05]). No difference was observed in the time to defervescence or length of hospital stay between the two groups (P > 0.05). In complicated scrub typhus patients (n = 181), multivariate analysis showed that only APACHE II score was an independent risk factor for mortality (95% confidence interval, 1.11 to 1.56; P < 0.001). Our data suggest that outcomes of azithromycin therapy are comparable to those of doxycycline therapy in patients with complicated scrub typhus. PMID:24366734

The sensitivity of clinical diagnostic methods in the diagnosis of diabetic neuropathy.

PubMed

Onde, M E; Ozge, A; Senol, M G; Togrol, E; Ozdag, F; Saracoglu, M; Misirli, H

2008-01-01

This study assessed the sensitivity of various methods for the clinical diagnosis of diabetic peripheral neuropathy. A total of 147 randomly selected patients with diabetes mellitus and 65 age- and sex-matched healthy controls were evaluated by various clinical (the neuropathy symptom score [NSS], the neuropathy disability score [NDS], vibration perception thresholds [VPTs], Tinel's sign and Phalen's sign), laboratory (fasting plasma glucose and glycosylated haemoglobin levels) and electro-physiological (nerve conduction studies, H-reflex and F-wave measurements) methods. In the patient group, 8.2% had an abnormal NSS, 28.5% had a positive Phalen's sign, 32.6% had a positive Tinel's sign, 42.8% had an abnormal VPT and 57.1% had an abnormal NDS. Significant correlations were found between electro-physiologically confirmed neuropathy and the two provocation tests and abnormal VPTs. In conclusion, assessment with a complete neurological examination and standard electrophysiological tests is very important for the diagnosis of diabetic peripheral neuropathy and the prevention of morbidity in patients with or without symptoms.

Hemiarch Reconstruction Vs Clamped Aortic Anastomosis for Concomitant Ascending Aortic Aneurysm.

PubMed

Sultan, Ibrahim; Bianco, Valentino; Yajzi, Ibrahim; Kilic, Arman; Dufendach, Keith; Cardounel, Arturo; Althouse, Andrew D; Masri, Ahmad; Navid, Forozan; Gleason, Thomas G

2018-05-03

Deep hypothermic circulatory arrest (DHCA) is often avoided in patients with concomitant ascending aortic pathology when treating other cardiac disease to avoid increased risk of morbidity and mortality. We hypothesized that the use of DHCA with retrograde cerebral perfusion (RCP) does not add incremental risk to ascending aortic replacement alone in the setting of concomitant cardiac surgery. 408 ascending aortic ± hemiarch replacements and aortic (root)/mitral/tricuspid valve(s), CABG, or MAZE procedures were performed for concomitant cardiac disease. DHCA with RCP was used for all hemiarch replacements or the ascending aorta was replaced with an aortic cross-clamp proximal to the innominate artery. Propensity-score matching was used to match similar ascending patients vs. hemiarch patients; the final propensity score matched patients on age, gender, BMI, previous heart surgery, pre-op aortic insufficiency, pre-op aortic stenosis, pre-op EF, and operative variables. Propensity-score matching yielded 116 pairs of Non-hemiarch patients vs. 116 hemiarch patients. Within the propensity-score matched cohort, there were no differences in postoperative stroke (1.7% vs. 3.4%, p = 0.41), new postoperative dialysis (6.0% vs. 5.2%, p = 0.78), postoperative renal insufficiency (27.6% vs. 19.8%, p = 0.16), 30-day mortality (2.6% vs. 3.4%, p = 0.701), or 1-year mortality (4.3% vs. 4.3%, p = 1.00) CONCLUSIONS: Hemiarch replacement using DHCA with RCP does not increase the risk of operative complications compared to a normothermic, clamped-distal aortic anastomosis, and therefore its use should not be limited when planning complex multi-procedural reconstructions during elective ascending thoracic aortic replacement with concomitant cardiac surgery. Copyright © 2018. Published by Elsevier Inc.

Longitudinal assessment of gender differences in the development of PTSD among US military personnel deployed in support of the operations in Iraq and Afghanistan.

PubMed

Jacobson, Isabel G; Donoho, Carrie J; Crum-Cianflone, Nancy F; Maguen, Shira

2015-09-01

Divergent findings from previous research examining gender differences in the development of posttraumatic stress disorder (PTSD) among US military members deployed to the operations in Iraq or Afghanistan (recent operations) prompted this study utilizing a matching approach to examine whether risk for new-onset PTSD and PTSD severity scores differed by gender. US military members from the Millennium Cohort Study deployed in support of the recent operations were followed for approximately 7 years from baseline through 2 follow-up periods between 2001 and 2008. Propensity score matching was used to match 1 male to each female using demographic, military, and behavioral factors including baseline sexual assault. Analyses were stratified by combat experience defined as reporting at least one of five exposures during follow-up. Outcome measures included a positive screen for PTSD and severity scores measured by the PTSD Patient Checklist-Civilian Version. Discrete-time survival analysis quantified the association between gender and incident PTSD. Among 4684 matched subjects (2342 women and men), 6.7% of women and 6.1% of men developed PTSD during follow-up. Results showed no significant gender differences for the likelihood of developing PTSD or for PTSD severity scores among women and men who reported combat experience and among those who did not. This study is the first of its kind to match a large population of male and female service members on important baseline characteristics including sexual assault. Findings suggest that while combat deployed personnel develop PTSD, women do not have a significantly different risk for developing PTSD than men after experiencing combat. Published by Elsevier Ltd.

Effect of Radiotherapy Planning Complexity on Survival of Elderly Patients With Unresected Localized Lung Cancer

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

Park, Chang H.; Bonomi, Marcelo; Cesaretti, Jamie

2011-11-01

Purpose: To evaluate whether complex radiotherapy (RT) planning was associated with improved outcomes in a cohort of elderly patients with unresected Stage I-II non-small-cell lung cancer (NSCLC). Methods and Materials: Using the Surveillance, Epidemiology, and End Results registry linked to Medicare claims, we identified 1998 patients aged >65 years with histologically confirmed, unresected stage I-II NSCLC. Patients were classified into an intermediate or complex RT planning group using Medicare physician codes. To address potential selection bias, we used propensity score modeling. Survival of patients who received intermediate and complex simulation was compared using Cox regression models adjusting for propensity scoresmore » and in a stratified and matched analysis according to propensity scores. Results: Overall, 25% of patients received complex RT planning. Complex RT planning was associated with better overall (hazard ratio 0.84; 95% confidence interval, 0.75-0.95) and lung cancer-specific (hazard ratio 0.81; 95% confidence interval, 0.71-0.93) survival after controlling for propensity scores. Similarly, stratified and matched analyses showed better overall and lung cancer-specific survival of patients treated with complex RT planning. Conclusions: The use of complex RT planning is associated with improved survival among elderly patients with unresected Stage I-II NSCLC. These findings should be validated in prospective randomized controlled trials.« less

Secondary-structure matching (SSM), a new tool for fast protein structure alignment in three dimensions.

PubMed

Krissinel, E; Henrick, K

2004-12-01

The present paper describes the SSM algorithm of protein structure comparison in three dimensions, which includes an original procedure of matching graphs built on the protein's secondary-structure elements, followed by an iterative three-dimensional alignment of protein backbone Calpha atoms. The SSM results are compared with those obtained from other protein comparison servers, and the advantages and disadvantages of different scores that are used for structure recognition are discussed. A new score, balancing the r.m.s.d. and alignment length Nalign, is proposed. It is found that different servers agree reasonably well on the new score, while showing considerable differences in r.m.s.d. and Nalign.

HIV-associated cognitive disorders in perinatally infected children and adolescents: a novel composite cognitive domains score.

PubMed

Phillips, Nicole J; Hoare, Jacqueline; Stein, Dan J; Myer, Landon; Zar, Heather J; Thomas, Kevin G F

2018-04-22

Accurate assessment of HIV-associated cognitive disorders in perinatally infected children and adolescents is challenging. Assessments of general intellectual functioning, or global cognition, may not provide information regarding domain-specific strengths and weaknesses, and may therefore fail to detect, impaired trajectories of development within particular cognitive domains. We compare the efficacy of global cognitive scores to that of composite cognitive domain scores in detecting cognitive disorders in a sample of perinatally HIV-infected children, and a demographically matched HIV negative control group, drawn from the Cape Town Adolescent Antiretroviral Cohort (CTAAC) study. All children were administered a comprehensive neuropsychological test battery. Using data from that test battery, we created ten separate composite cognitive domains: general intellectual functioning, attention, working memory, visual memory, verbal memory, language, visual spatial ability, motor coordination, processing speed and executive function. Within each domain, each test bore a high level of association with each of the other tests in that domain (Cronbach's α ≥ .70 for all domains). We found that composite domain scores calculated on whole-sample data were significantly higher than those calculated using control-sample data. Our comparison of a global cognitive score to composite domain scores suggested that the latter provided more detailed information (regarding strengths, weaknesses, areas of impairment), and when compared to global scores, were more sensitive in detecting HIV-associated cognitive disorders, and were able to distinguish HIV-infected patients from uninfected controls. Hence, we recommend using this method of composite cognitive domains scores, rather than global aggregate scores, when assessing cognitive function in paediatric HIV. This method provides a convenient and relatively accurate assessment that might help with cross-cultural and cross-region comparisons as researchers try to detect cognitive impairment patterns in HIV-infected children and adolescents globally.

Evidence for age-associated cognitive decline from Internet game scores.

PubMed

Geyer, Jason; Insel, Philip; Farzin, Faraz; Sternberg, Daniel; Hardy, Joseph L; Scanlon, Michael; Mungas, Dan; Kramer, Joel; Mackin, R Scott; Weiner, Michael W

2015-06-01

Lumosity's Memory Match (LMM) is an online game requiring visual working memory. Change in LMM scores may be associated with individual differences in age-related changes in working memory. Effects of age and time on LMM learning and forgetting rates were estimated using data from 1890 game sessions for users aged 40 to 79 years. There were significant effects of age on baseline LMM scores (β = -.31, standard error or SE = .02, P < .0001) and lower learning rates (β = -.0066, SE = .0008, P < .0001). A sample size of 202 subjects/arm was estimated for a 1-year study for subjects in the lower quartile of game performance. Online memory games have the potential to identify age-related decline in cognition and to identify subjects at risk for cognitive decline with smaller sample sizes and lower cost than traditional recruitment methods.

Emotion processing for arousal and neutral content in Alzheimer's disease.

PubMed

Satler, Corina; Uribe, Carlos; Conde, Carlos; Da-Silva, Sergio Leme; Tomaz, Carlos

2010-02-01

Objective. To assess the ability of Alzheimer's disease (AD) patients to perceive emotional information and to assign subjective emotional rating scores to audiovisual presentations. Materials and Methods. 24 subjects (14 with AD, matched to controls for age and educational levels) were studied. After neuropsychological assessment, they watched a Neutral story and then a story with Emotional content. Results. Recall scores for both stories were significantly lower in AD (Neutral and Emotional: P = .001). CG assigned different emotional scores for each version of the test, P = .001, while ratings of AD did not differ, P = .32. Linear regression analyses determined the best predictors of emotional rating and recognition memory for each group among neuropsychological tests battery. Conclusions. AD patients show changes in emotional processing on declarative memory and a preserved ability to express emotions in face of arousal content. The present findings suggest that these impairments are due to general cognitive decline.

Advanced Issues in Propensity Scores: Longitudinal and Missing Data

ERIC Educational Resources Information Center

Kupzyk, Kevin A.; Beal, Sarah J.

2017-01-01

In order to investigate causality in situations where random assignment is not possible, propensity scores can be used in regression adjustment, stratification, inverse-probability treatment weighting, or matching. The basic concepts behind propensity scores have been extensively described. When data are longitudinal or missing, the estimation and…

Assessing the impact of natural policy experiments on socioeconomic inequalities in health: how to apply commonly used quantitative analytical methods?

PubMed

Hu, Yannan; van Lenthe, Frank J; Hoffmann, Rasmus; van Hedel, Karen; Mackenbach, Johan P

2017-04-20

The scientific evidence-base for policies to tackle health inequalities is limited. Natural policy experiments (NPE) have drawn increasing attention as a means to evaluating the effects of policies on health. Several analytical methods can be used to evaluate the outcomes of NPEs in terms of average population health, but it is unclear whether they can also be used to assess the outcomes of NPEs in terms of health inequalities. The aim of this study therefore was to assess whether, and to demonstrate how, a number of commonly used analytical methods for the evaluation of NPEs can be applied to quantify the effect of policies on health inequalities. We identified seven quantitative analytical methods for the evaluation of NPEs: regression adjustment, propensity score matching, difference-in-differences analysis, fixed effects analysis, instrumental variable analysis, regression discontinuity and interrupted time-series. We assessed whether these methods can be used to quantify the effect of policies on the magnitude of health inequalities either by conducting a stratified analysis or by including an interaction term, and illustrated both approaches in a fictitious numerical example. All seven methods can be used to quantify the equity impact of policies on absolute and relative inequalities in health by conducting an analysis stratified by socioeconomic position, and all but one (propensity score matching) can be used to quantify equity impacts by inclusion of an interaction term between socioeconomic position and policy exposure. Methods commonly used in economics and econometrics for the evaluation of NPEs can also be applied to assess the equity impact of policies, and our illustrations provide guidance on how to do this appropriately. The low external validity of results from instrumental variable analysis and regression discontinuity makes these methods less desirable for assessing policy effects on population-level health inequalities. Increased use of the methods in social epidemiology will help to build an evidence base to support policy making in the area of health inequalities.

Trends in NRMP Data from 2007-2014 for U.S. Seniors Matching into Emergency Medicine.

PubMed

Manthey, David E; Hartman, Nicholas D; Newmyer, Aileen; Gunalda, Jonah C; Hiestand, Brian C; Askew, Kim L; Lefebvre, Cedric

2017-01-01

Since 1978, the National Residency Matching Program (NRMP) has published data demonstrating characteristics of applicants who have matched into their preferred specialty in the NRMP main residency match. These data have been published approximately every two years. There is limited information about trends within these published data for students matching into emergency medicine (EM). Our objective was to investigate and describe trends in NRMP data to include the following: the ratio of applicants to available EM positions; United State Medical Licensing Examination (USMLE) Step 1 and Step 2 scores (compared to the national means); number of programs ranked; and Alpha Omega Alpha Honor Medical Society (AOA) membership among U.S. seniors matching into EM. This was a retrospective observational review of NRMP data published between 2007 and 2016. We analyzed the data using analysis of variance (ANOVA) or Kruskal-Wallis testing, and Fischer's exact or chi-squared testing, as appropriate to determine statistical significance. The ratio of applicants to available EM positions remained essentially stable from 2007 to 2014 but did increase slightly in 2016. We observed a net upward trend in overall Step 1 and Step 2 scores for EM applicants. However, this did not outpace the national trend increase in Step 1 and 2 scores overall. There was an increase in the mean number of programs ranked by EM applicants over the years studied from 7.8 (SD4.2) to 9.2 (SD5.0, p<0.001), driven predominantly by the cohort of U.S. students successful in the match. Among time intervals, there was a difference in the number of EM applicants with AOA membership (p=0.043) due to a drop in the number of AOA students in 2011. No sustained statistical trend in AOA membership was identified over the seven-year period studied. NRMP data demonstrate trends among EM applicants that are similar to national trends in other specialties for USMLE board scores, and a modest increase in number of programs ranked. AOA membership was largely stable. EM does not appear to have become more competitive relative to other specialties or previous years in these categories.

Idiom Comprehension Deficits in High-Functioning Autism Spectrum Disorder Using a Korean Autism Social Language Task

PubMed Central

Lee, Seul Bee; Song, Seung Ha; Ham, Ju Hyun; Song, Dong Ho

2015-01-01

Purpose High-functioning autism spectrum disorder (ASD) involves pragmatic impairment of language skills. Among numerous tasks for assessing pragmatic linguistic skills, idioms are important to evaluating high-functioning ASD. Nevertheless, no assessment tool has been developed with specific consideration of Korean culture. Therefore, we designed the Korean Autism Social Language Task (KASLAT) to test idiom comprehension in ASD. The aim of the current study was to introduce this novel psychological tool and evaluate idiom comprehension deficits in high-functioning ASD. Materials and Methods The participants included 42 children, ages 6-11 years, who visited our child psychiatric clinic between April 2014 and May 2015. The ASD group comprised 16 children; the attention deficit hyperactivity disorder (ADHD) group consisted of 16 children. An additional 10 normal control children who had not been diagnosed with either disorder participated in this study. Idiom comprehension ability was assessed in these three groups using the KASLAT. Results Both ASD and ADHD groups had significantly lower scores on the matched and mismatched tasks, compared to the normal control children (matched tasks mean score: ASD 11.56, ADHD 11.56, normal control 14.30; mismatched tasks mean score: ASD 6.50, ADHD 4.31, normal control 11.30). However, no significant differences were found in scores of KASLAT between the ADHD and ASD groups. Conclusion These findings suggest that children with ASD exhibit greater impairment in idiom comprehension, compared to normal control children. The KASLAT may be useful in evaluating idiom comprehension ability. PMID:26446644

Doubly robust matching estimators for high dimensional confounding adjustment.

PubMed

Antonelli, Joseph; Cefalu, Matthew; Palmer, Nathan; Agniel, Denis

2018-05-11

Valid estimation of treatment effects from observational data requires proper control of confounding. If the number of covariates is large relative to the number of observations, then controlling for all available covariates is infeasible. In cases where a sparsity condition holds, variable selection or penalization can reduce the dimension of the covariate space in a manner that allows for valid estimation of treatment effects. In this article, we propose matching on both the estimated propensity score and the estimated prognostic scores when the number of covariates is large relative to the number of observations. We derive asymptotic results for the matching estimator and show that it is doubly robust in the sense that only one of the two score models need be correct to obtain a consistent estimator. We show via simulation its effectiveness in controlling for confounding and highlight its potential to address nonlinear confounding. Finally, we apply the proposed procedure to analyze the effect of gender on prescription opioid use using insurance claims data. © 2018, The International Biometric Society.

[Are Two-Year Vocational Retraining Programs Really Better than One-Year Programs? Findings of a Propensity Score Matched Analysis].

PubMed

Bethge, M; Streibelt, M

2015-12-01

To analyze if one- and 2-year vocational retraining programs achieve similar effects on employment. Analyses were performed with longitudinal administrative data. We included persons aged 18-59 years, who started their retraining between January and June 2005. One- and 2-year program participants were matched by propensity scores. The matched groups were balanced regarding all baseline scores (one-year program: n=514; 2-year program: n=514). 4 and 5 years after start of the vocational retraining program, annual income, the duration of welfare benefits and the risk of a disability pension were comparable in both groups. However, the accumulative income between 2005 and 2009 was 9 294 Euro higher (95% CI: 3 656-14 932 Euro) in one-year retraining participants. Moreover, participants of one-year programs received less welfare benefits. The development of a vocational rehabilitation strategy needs to consider the accumulative advantage of one-year programs. © Georg Thieme Verlag KG Stuttgart · New York.

Aggregate Interview Method of ranking orthopedic applicants predicts future performance.

PubMed

Geissler, Jacqueline; VanHeest, Ann; Tatman, Penny; Gioe, Terence

2013-07-01

This article evaluates and describes a process of ranking orthopedic applicants using what the authors term the Aggregate Interview Method. The authors hypothesized that higher-ranking applicants using this method at their institution would perform better than those ranked lower using multiple measures of resident performance. A retrospective review of 115 orthopedic residents was performed at the authors' institution. Residents were grouped into 3 categories by matching rank numbers: 1-5, 6-14, and 15 or higher. Each rank group was compared with resident performance as measured by faculty evaluations, the Orthopaedic In-Training Examination (OITE), and American Board of Orthopaedic Surgery (ABOS) test results. Residents ranked 1-5 scored significantly better on patient care, behavior, and overall competence by faculty evaluation (P<.05). Residents ranked 1-5 scored higher on the OITE compared with those ranked 6-14 during postgraduate years 2 and 3 (P⩽.5). Graduates who had been ranked 1-5 had a 100% pass rate on the ABOS part 1 examination on the first attempt. The most favorably ranked residents performed at or above the level of other residents in the program; they did not score inferiorly on any measure. These results support the authors' method of ranking residents. The rigorous Aggregate Interview Method for ranking applicants consistently identified orthopedic resident candidates who scored highly on the Accreditation Council for Graduate Medical Education resident core competencies as measured by faculty evaluations, performed above the national average on the OITE, and passed the ABOS part 1 examination at rates exceeding the national average. Copyright 2013, SLACK Incorporated.

The Physician Recommendation Coding System (PhyReCS): A Reliable and Valid Method to Quantify the Strength of Physician Recommendations During Clinical Encounters.

PubMed

Scherr, Karen A; Fagerlin, Angela; Williamson, Lillie D; Davis, J Kelly; Fridman, Ilona; Atyeo, Natalie; Ubel, Peter A

2017-01-01

Physicians' recommendations affect patients' treatment choices. However, most research relies on physicians' or patients' retrospective reports of recommendations, which offer a limited perspective and have limitations such as recall bias. To develop a reliable and valid method to measure the strength of physician recommendations using direct observation of clinical encounters. Clinical encounters (n = 257) were recorded as part of a larger study of prostate cancer decision making. We used an iterative process to create the 5-point Physician Recommendation Coding System (PhyReCS). To determine reliability, research assistants double-coded 50 transcripts. To establish content validity, we used 1-way analyses of variance to determine whether relative treatment recommendation scores differed as a function of which treatment patients received. To establish concurrent validity, we examined whether patients' perceived treatment recommendations matched our coded recommendations. The PhyReCS was highly reliable (Krippendorf's alpha = 0.89, 95% CI [0.86, 0.91]). The average relative treatment recommendation score for each treatment was higher for individuals who received that particular treatment. For example, the average relative surgery recommendation score was higher for individuals who received surgery versus radiation (mean difference = 0.98, SE = 0.18, P < 0.001) or active surveillance (mean difference = 1.10, SE = 0.14, P < 0.001). Patients' perceived recommendations matched coded recommendations 81% of the time. The PhyReCS is a reliable and valid way to capture the strength of physician recommendations. We believe that the PhyReCS would be helpful for other researchers who wish to study physician recommendations, an important part of patient decision making. © The Author(s) 2016.

Association between use of pre-hospital ECG and 30-day mortality: A large cohort study of patients experiencing chest pain.

PubMed

Rawshani, Nina; Rawshani, Araz; Gelang, Carita; Herlitz, Johan; Bång, Angela; Andersson, Jan-Otto; Gellerstedt, Martin

2017-12-01

In the assessment of patients with chest pain, there is support for the use of pre-hospital ECG in the literature and in the care guidelines. Using propensity score methods, we aim to examine whether the mere acquisition of a pre-hospital ECG among patients with chest pain affects the outcome (30-day mortality). The association between pre-hospital ECG and 30-day mortality was studied in the overall cohort (n=13151), as well as in the one-to-one matched cohort with 2524 patients not examined with pre-hospital ECG and 2524 patients examined with pre-hospital ECG. In the overall cohort, 21% (n=2809) did not undergo an ECG tracing in the pre-hospital setting. Among those who had pain during transport, 14% (n=1159) did not undergo a pre-hospital ECG while 32% (n=1135) of those who did not have pain underwent an ECG tracing. In the overall cohort, the OR for 30-day mortality in patients who had a pre-hospital ECG, as compared with those who did not, was 0.63 (95% CI 0.05-0.79; p<0.001). In the matched cohort, the OR was 0.65 (95% CI 0.49-0.85; p<0.001). Using the propensity score, in the overall cohort, the corresponding HR was 0.65 (95% CI 0.58-0.74). Using propensity score methods, we provide real-world data demonstrating that the adjusted risk of death was considerably lower among the cases in whoma pre-hospital ECG was used. The PH-ECG is underused among patients with chest discomfort and the mere acquisition of a pre-hospital ECG may reduce mortality. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of Core-Needle Biopsy and Fine-Needle Aspiration for Evaluating Thyroid Incidentalomas Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Propensity Score Analysis.

PubMed

Suh, Chong Hyun; Choi, Young Jun; Lee, Jong Jin; Shim, Woo Hyun; Baek, Jung Hwan; Chung, Han Cheol; Shong, Young Kee; Song, Dong Eun; Sung, Tae Yon; Lee, Jeong Hyun

2017-10-01

This study used a propensity score analysis to assess the roles of core-needle biopsy (CNB) and fine-needle aspiration (FNA) in the evaluation of thyroid incidentalomas detected on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). The study population was obtained from a historical cohort who underwent 18 F-FDG PET/CT between October 2008 and September 2015. Patients were included who underwent ultrasound-guided CNB or FNA for incidental focal uptake of 18 F-FDG in the thyroid gland on PET/CT. The primary study outcomes included the inconclusive result rates in the CNB and FNA groups. The secondary outcome measures included the non-diagnostic result rate and the diagnostic performance for neoplasms. Multivariate analysis, propensity score matching, and inverse probability weighting were conducted. A total of 1360 nodules from 1338 patients were included in this study: 859 nodules from 850 patients underwent FNA, and 501 nodules from 488 patients underwent CNB. Compared to FNA, CNB demonstrated a significantly lower inconclusive result rate in the pooled cohort (23.8% vs. 35.4%; p < 0.001), propensity score-matched cohorts (22.9% vs. 36.6%; p < 0.001), and with inverse probability weighting (22.4% vs. 35.2%; p < 0.001). Non-diagnostic result rates were also significantly lower in CNB than in FNA. The diagnostic performance of the two groups in the pooled and matched cohorts was similar, with no significant differences found. The significantly lower inconclusive result rates in CNB than in FNA were consistent within the propensity score-matched cohorts. Therefore, CNB appears to be a promising diagnostic tool for patients with thyroid incidentalomas detected on 18 F-FDG PET/CT.

Comparing the therapeutic efficacies of third-generation cephalosporins and broader-spectrum β-lactams as appropriate empirical therapy in adults with community-onset monomicrobial Enterobacteriaceae bacteraemia: a propensity score matched analysis.

PubMed

Lee, Chung-Hsun; Hsieh, Chih-Chia; Hong, Ming-Yuan; Hung, Yuan-Pin; Ko, Wen-Chien; Lee, Ching-Chi

2017-05-01

In this study, the therapeutic efficacy of third-generation cephalosporins (3GCs) was compared with that of broader-spectrum β-lactams (BSBLs) [fourth-generation cephalosporins (4GCs) and carbapenems] as empirical therapy in adults with community-onset monomicrobial Enterobacteriaceae bacteraemia. Compared with those in the 3GC group (n = 477), a significantly higher proportion of patients in the BSBL group (n = 141) had initial presentation with severe sepsis or septic shock, critical illness (Pitt bacteraemia score ≥4) at bacteraemia onset and fatal co-morbidities (McCabe classification). For propensity score matching, 318 of the 477 patients in the 3GC group were matched with 106 patients in the BSBL group with the closest propensity scores on the basis of five independent predictors of 28-day mortality. After appropriate matching, no significant differences were observed in major baseline characteristics between the 3GC and BSBL groups in terms of causative micro-organism, bacteraemia severity, major source of bacteraemia, major co-morbidities and severity of co-morbidity. Consequently, the early clinical failure rate (12.9% vs. 12.3%; P = 0.87), bacteraemia severity (Pitt bacteraemia score ≥4; 4.6% vs. 8.2%; P = 0.17) at Day 3, and 3-day (3.8% vs. 7.5%; P = 0.11) and 28-day (13.2% vs. 17.0%; P = 0.33) crude mortality rates between the two groups were similar. These data suggest that the efficacy of 3GCs is similar to that of 4GCs or carbapenems when used as empirical antimicrobial therapy for community-onset Enterobacteriaceae bacteraemia. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Position related analysis of the appearance of and relationship between post-match physical and mental fatigue in university rugby football players.

PubMed

Mashiko, T; Umeda, T; Nakaji, S; Sugawara, K

2004-10-01

The relationship between physical and mental fatigue in rugby players after a match was examined, taking into account the position played. The Profile of Mood State (POMS) test, blood biochemical parameters, and serum opsonic activity were measured for 37 university rugby football players before and after a match. There were no differences in parameter changes except for blood urea nitrogen (a marker for protein catabolism) between the forwards and the backs. Regarding correlation between physical and mental fatigue, in forwards, changes in POMS scores showed a positive correlation with changes in the levels of enzymes of skeletal muscle origin, such as glutamate oxaloacetic transaminase (GOT) and lactate dehydrogenase (LDH), and free fatty acid (FFA) level and white blood cell count (for example, in the Total Mood Disturbance (TMD) score, Spearman's correlation coefficient was 0.417 and p<0.05 with GOT, 0.413 and p<0.05 with LDH, 0.462 and p<0.05 with FFA, and 0.442 and p<0.05 with white blood cell count). In backs, changes in the POMS scores showed a positive correlation with changes in the levels of lipid related parameters such as FFA and total cholesterol (for example, as regards the TMD score, Spearman's correlation coefficient was 0.481 and p<0.05 with FFA, and 0.550 and p<0.05 with total cholesterol), and showed a negative correlation with change in blood glucose level (TMD score, -0.517 and p<0.05). The different exercise loading of the position played during a rugby match may cause differences in the relationship between physical and mental fatigue.

Method for combined biometric and chemical analysis of human fingerprints.

PubMed

Staymates, Jessica L; Orandi, Shahram; Staymates, Matthew E; Gillen, Greg

This paper describes a method for combining direct chemical analysis of latent fingerprints with subsequent biometric analysis within a single sample. The method described here uses ion mobility spectrometry (IMS) as a chemical detection method for explosives and narcotics trace contamination. A collection swab coated with a high-temperature adhesive has been developed to lift latent fingerprints from various surfaces. The swab is then directly inserted into an IMS instrument for a quick chemical analysis. After the IMS analysis, the lifted print remains intact for subsequent biometric scanning and analysis using matching algorithms. Several samples of explosive-laden fingerprints were successfully lifted and the explosives detected with IMS. Following explosive detection, the lifted fingerprints remained of sufficient quality for positive match scores using a prepared gallery consisting of 60 fingerprints. Based on our results ( n  = 1200), there was no significant decrease in the quality of the lifted print post IMS analysis. In fact, for a small subset of lifted prints, the quality was improved after IMS analysis. The described method can be readily applied to domestic criminal investigations, transportation security, terrorist and bombing threats, and military in-theatre settings.

Proton pump inhibitor use and risk of adverse cardiovascular events in aspirin treated patients with first time myocardial infarction: nationwide propensity score matched study

PubMed Central

Grove, Erik L; Hansen, Peter Riis; Olesen, Jonas B; Ahlehoff, Ole; Selmer, Christian; Lindhardsen, Jesper; Madsen, Jan Kyst; Køber, Lars; Torp-Pedersen, Christian; Gislason, Gunnar H

2011-01-01

Objective To examine the effect of proton pump inhibitors on adverse cardiovascular events in aspirin treated patients with first time myocardial infarction. Design Retrospective nationwide propensity score matched study based on administrative data. Setting All hospitals in Denmark. Participants All aspirin treated patients surviving 30 days after a first myocardial infarction from 1997 to 2006, with follow-up for one year. Patients treated with clopidogrel were excluded. Main outcome measures The risk of the combined end point of cardiovascular death, myocardial infarction, or stroke associated with use of proton pump inhibitors was analysed using Kaplan-Meier analysis, Cox proportional hazard models, and propensity score matched Cox proportional hazard models. Results 3366 of 19 925 (16.9%) aspirin treated patients experienced recurrent myocardial infarction, stroke, or cardiovascular death. The hazard ratio for the combined end point in patients receiving proton pump inhibitors based on the time dependent Cox proportional hazard model was 1.46 (1.33 to 1.61; P<0.001) and for the propensity score matched model based on 8318 patients it was 1.61 (1.45 to 1.79; P<0.001). A sensitivity analysis showed no increase in risk related to use of H2 receptor blockers (1.04, 0.79 to 1.38; P=0.78). Conclusion In aspirin treated patients with first time myocardial infarction, treatment with proton pump inhibitors was associated with an increased risk of adverse cardiovascular events. PMID:21562004

Normal Variability of Weekly Musculoskeletal Screening Scores and the Influence of Training Load across an Australian Football League Season.

PubMed

Esmaeili, Alireza; Stewart, Andrew M; Hopkins, William G; Elias, George P; Lazarus, Brendan H; Rowell, Amber E; Aughey, Robert J

2018-01-01

Aim: The sit and reach test (S&R), dorsiflexion lunge test (DLT), and adductor squeeze test (AST) are commonly used in weekly musculoskeletal screening for athlete monitoring and injury prevention purposes. The aim of this study was to determine the normal week to week variability of the test scores, individual differences in variability, and the effects of training load on the scores. Methods: Forty-four elite Australian rules footballers from one club completed the weekly screening tests on day 2 or 3 post-main training (pre-season) or post-match (in-season) over a 10 month season. Ratings of perceived exertion and session duration for all training sessions were used to derive various measures of training load via both simple summations and exponentially weighted moving averages. Data were analyzed via linear and quadratic mixed modeling and interpreted using magnitude-based inference. Results: Substantial small to moderate variability was found for the tests at both season phases; for example over the in-season, the normal variability ±90% confidence limits were as follows: S&R ±1.01 cm, ±0.12; DLT ±0.48 cm, ±0.06; AST ±7.4%, ±0.6%. Small individual differences in variability existed for the S&R and AST (factor standard deviations between 1.31 and 1.66). All measures of training load had trivial effects on the screening scores. Conclusion: A change in a test score larger than the normal variability is required to be considered a true change. Athlete monitoring and flagging systems need to account for the individual differences in variability. The tests are not sensitive to internal training load when conducted 2 or 3 days post-training or post-match, and the scores should be interpreted cautiously when used as measures of recovery.

An Examination of Differences in Psychological Resilience between Social Anxiety Disorder and Posttraumatic Stress Disorder in the Context of Early Childhood Trauma

PubMed Central

Marx, Melanie; Young, Susanne Y.; Harvey, Justin; Rosenstein, David; Seedat, Soraya

2017-01-01

Background: Much of the research on anxiety disorders has focused on associated risk factors with less attention paid to factors such as resilience that may mitigate risk or offer protection in the face of psychopathology. Objective: This study sought to compare resilience in individuals with posttraumatic stress disorder (PTSD) and social anxiety disorder (SAD) relative to age-, gender- and education- matched individuals with no psychiatric disorder. We further assessed the correlation of resilience scores with childhood trauma severity and type. Method: The sample comprised of 93 participants, 40 with SAD with childhood trauma), 22 with PTSD with childhood trauma, and 31 with no psychiatric disorder (i.e., healthy matched controls). Participants were administered the Mini-International Neuropsychiatric Interview (MINI), Liebowitz Social Anxiety Scale (LSAS), Clinician-Administered PTSD Scale (CAPS), Childhood Trauma Questionnaire—Short Form (CTQ-SF), and the Connor-Davidson Resilience Scale (CD-RISC). The mean age of participants was 34 years (SD = 11). 52 Participants were female (55.9%) and 54 Caucasian (58.1%). Analysis of variance was used to assess for significant group differences in resilience scores. Non-parametric correlation analyses were conducted for resilience and different types of childhood trauma. Results: There were significant differences in resilience between the SAD and PTSD groups with childhood trauma, and controls. Both disorder groups had significantly lower levels of resilience than healthy controls. No significant correlation was found between total resilience scores and childhood trauma scores in the childhood trauma (SAD and PTSD) groups. However, in the combined dataset (SAD, PTSD, healthy controls), significant negative correlations were found between resilience scores and emotional abuse, emotional neglect, and total childhood trauma scores. Conclusions: Patients who have PTSD and SAD with childhood trauma appear to be significantly less resilient than those with no disorder. Assessing and addressing resilience in these disorders, particularly when childhood trauma is present, may facilitate long-term recovery and warrants further investigation. PMID:29312023

An Examination of Differences in Psychological Resilience between Social Anxiety Disorder and Posttraumatic Stress Disorder in the Context of Early Childhood Trauma.

PubMed

Marx, Melanie; Young, Susanne Y; Harvey, Justin; Rosenstein, David; Seedat, Soraya

2017-01-01

Background: Much of the research on anxiety disorders has focused on associated risk factors with less attention paid to factors such as resilience that may mitigate risk or offer protection in the face of psychopathology. Objective: This study sought to compare resilience in individuals with posttraumatic stress disorder (PTSD) and social anxiety disorder (SAD) relative to age-, gender- and education- matched individuals with no psychiatric disorder. We further assessed the correlation of resilience scores with childhood trauma severity and type. Method: The sample comprised of 93 participants, 40 with SAD with childhood trauma), 22 with PTSD with childhood trauma, and 31 with no psychiatric disorder (i.e., healthy matched controls). Participants were administered the Mini-International Neuropsychiatric Interview (MINI), Liebowitz Social Anxiety Scale (LSAS), Clinician-Administered PTSD Scale (CAPS), Childhood Trauma Questionnaire-Short Form (CTQ-SF), and the Connor-Davidson Resilience Scale (CD-RISC). The mean age of participants was 34 years ( SD = 11). 52 Participants were female (55.9%) and 54 Caucasian (58.1%). Analysis of variance was used to assess for significant group differences in resilience scores. Non-parametric correlation analyses were conducted for resilience and different types of childhood trauma. Results: There were significant differences in resilience between the SAD and PTSD groups with childhood trauma, and controls. Both disorder groups had significantly lower levels of resilience than healthy controls. No significant correlation was found between total resilience scores and childhood trauma scores in the childhood trauma (SAD and PTSD) groups. However, in the combined dataset (SAD, PTSD, healthy controls), significant negative correlations were found between resilience scores and emotional abuse, emotional neglect, and total childhood trauma scores. Conclusions: Patients who have PTSD and SAD with childhood trauma appear to be significantly less resilient than those with no disorder. Assessing and addressing resilience in these disorders, particularly when childhood trauma is present, may facilitate long-term recovery and warrants further investigation.

Performance of Disease Risk Score Matching in Nested Case-Control Studies: A Simulation Study.

PubMed

Desai, Rishi J; Glynn, Robert J; Wang, Shirley; Gagne, Joshua J

2016-05-15

In a case-control study, matching on a disease risk score (DRS), which includes many confounders, should theoretically result in greater precision than matching on only a few confounders; however, this has not been investigated. We simulated 1,000 hypothetical cohorts with a binary exposure, a time-to-event outcome, and 13 covariates. Each cohort comprised 2 subcohorts of 10,000 patients each: a historical subcohort and a concurrent subcohort. DRS were estimated in the historical subcohorts and applied to the concurrent subcohorts. Nested case-control studies were conducted in the concurrent subcohorts using incidence density sampling with 2 strategies-matching on age and sex, with adjustment for additional confounders, and matching on DRS-followed by conditional logistic regression for 9 outcome-exposure incidence scenarios. In all scenarios, DRS matching yielded lower average standard errors and mean squared errors than did matching on age and sex. In 6 scenarios, DRS matching also resulted in greater empirical power. DRS matching resulted in less relative bias than did matching on age and sex at lower outcome incidences but more relative bias at higher incidences. Post-hoc analysis revealed that the effect of DRS model misspecification might be more pronounced at higher outcome incidences, resulting in higher relative bias. These results suggest that DRS matching might increase the statistical efficiency of case-control studies, particularly when the outcome is rare. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Increased Risk of Venous Thromboembolism in Women with Uterine Leiomyoma: A Nationwide, Population-Based Case-Control Study

PubMed Central

Huang, Hung-Kai; Kor, Chew-Teng; Chen, Ching-Pei; Chen, Hung-Te; Yang, Po-Ta; Tsai, Chen-Dao; Huang, Ching-Hui

2018-01-01

Background Venous thromboembolism (VTE) is a sex-specific disease that has different presentations between men and women. Women with uterine leiomyoma can present with VTE without exhibiting the traditional risk factors. We investigated the relationship between a history of uterine leiomyoma and the risk of VTE using the National Health Insurance Research Database (NHIRD). Methods We conducted a retrospective, nationwide, population-based case-control study using the NHIRD. We identified 2,282 patients with diagnosed VTE and 392,635 subjects without VTE from 2000 to 2013. After development of an age and index diagnosis year frequency-matched model and propensity score-matched model, 2 models with a case-to-control ratio of 1 to 4 were established. Using the diagnosis of uterine leiomyoma as the exposure factor, conditional logistic regression was performed to examine the association between uterine leiomyoma and VTE. Multiple logistic regression analysis was used to investigate the joint effect of uterine leiomyoma and comorbid diseases on the risk of VTE. Results A strong association was observed between uterine leiomyoma and VTE in the overall patient model, frequency-matched model and propensity score-matched model [p < 0.0001, odds ratio (OR): 1.547; p = 0.0005, OR: 1.486; p = 0.0405, OR: 1.26, respectively]. In the subgroup analyses, women with uterine leiomyoma who were ≥ 45 years old were less likely to experience VTE, but women with uterine leiomyoma and anemia, cancer, coronary artery disease or heart failure were more likely to experience VTE. Conclusions Women with uterine leiomyomas have an increased risk of developing VTE, especially during reproductive periods or in the presence of specific diseases. PMID:29375226

A comparison of propensity score-based approaches to health service evaluation: a case study of a preoperative physician-led clinic for high-risk surgical patients.

PubMed

Pham, Clarabelle T; Gibb, Catherine L; Mittinty, Murthy N; Fitridge, Robert A; Marshall, Villis R; Karnon, Jonathan D

2016-10-01

A physician-led clinic for the preoperative optimization and management of high-risk surgical patients was implemented in a South Australian public hospital in 2008. This study aimed to estimate the costs and effects of the clinic using a mixed retrospective and prospective observational study design. Alternative propensity score estimation methods were applied to retrospective routinely collected administrative and clinical data, using weighted and matched cohorts. Supplementary survey-based prospective data were collected to inform the analysis of the retrospective data and reduce potential unmeasured confounding. Using weighted cohorts, clinic patients had a significantly longer mean length of stay and higher mean cost. With the matched cohorts, reducing the calliper width resulted in a shorter mean length of stay in the clinic group, but the costs remained significantly higher. The prospective data indicated potential unmeasured confounding in all analyses other than in the most tightly matched cohorts. The application of alternative propensity-based approaches to a large sample of retrospective data, supplemented with a smaller sample of prospective data, informed a pragmatic approach to reducing potential observed and unmeasured confounding in an evaluation of a physician-led preoperative clinic. The need to generate tightly matched cohorts to reduce the potential for unmeasured confounding indicates that significant uncertainty remains around the effects of the clinic. This study illustrates the value of mixed retrospective and prospective observational study designs but also underlines the need to prospectively plan for the evaluation of costs and effects alongside the implementation of significant service innovations. © 2016 John Wiley & Sons, Ltd.

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study

PubMed Central

Jung, Gyoo Hwan; Jung, Jae Hyun; Ahn, Tae Sik; Lee, Joong Sub; Cho, Sung Yong; Jeong, Chang Wook; Lee, Seung Bae; Kim, Hyeon Hoe

2015-01-01

Purpose To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Materials and Methods Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Results Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4±13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. Conclusions RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures. PMID:26175872

Risk of high-grade cervical dysplasia and cervical cancer in women with systemic lupus erythematosus receiving immunosuppressive drugs.

PubMed

Feldman, C H; Liu, J; Feldman, S; Solomon, D H; Kim, S C

2017-06-01

Objective Prior studies suggest an increased risk of cervical cancer among women with systemic lupus erythematosus. However, the relationship with immunosuppressive drugs is not well studied in US nationwide cohorts. We compared the risk of high-grade cervical dysplasia and cervical cancer among women with systemic lupus erythematosus who started immunosuppressive drugs versus hydroxychloroquine. Methods We identified systemic lupus erythematosus patients initiating immunosuppressive drugs or hydroxychloroquine using claims data from two US commercial health plans and Medicaid (2000-2012). We used a validated claims-based algorithm to identify high-grade cervical dysplasia or cervical cancer. To account for potential confounders, including demographic factors, comorbidities, medication use, HPV vaccination status, and health care utilization, immunosuppressive drugs and hydroxychloroquine initiators were 1:1 matched on the propensity score. We used inverse variance-weighted, fixed effect models to pool hazard ratios from the propensity score-matched Medicaid and commercial cohorts. Results We included 2451 matched pairs of immunosuppressive drugs and hydroxychloroquine new users in the commercial cohort and 7690 matched pairs in Medicaid. In the commercial cohort, there were 14 cases of cervical dysplasia or cervical cancer among immunosuppressive drugs users and five cases among hydroxychloroquine users (hazard ratio 2.47, 95% CI 0.89-6.85, hydroxychloroquine = ref). In Medicaid, there were 46 cases among immunosuppressive drugs users and 29 cases in hydroxychloroquine users (hazard ratio 1.24, 95% CI 0.78-1.98, hydroxychloroquine = ref). The pooled hazard ratio of immunosuppressive drugs was 1.40 (95% CI 0.92-2.12). Conclusion Among women with systemic lupus erythematosus, immunosuppressive drugs may be associated with a greater, albeit not statistically significant, risk of high-grade cervical dysplasia and cervical cancer compared to patients receiving hydroxychloroquine alone.

The association of sleep difficulties with health-related quality of life among patients with fibromyalgia

PubMed Central

2012-01-01

Background Difficulty sleeping is common among patients with fibromyalgia (FM); however, its impact on health-related quality of life (HRQoL) is not well understood. The aim of the current study was to assess the burden of sleep difficulty symptoms on HRQoL among patients with FM. Methods The current study included data from the 2009 National Health and Wellness Survey (N=75,000), which is a cross-sectional, Internet-based survey representative of the adult US population. The prevalence of sleep difficulty symptoms among patients with FM (n=2,196) were compared with matched controls (n=2,194), identified using propensity-score matching. Additionally, the relationship between the number of sleep difficulty symptoms (none, one, or two or more) and HRQoL (using the SF-12v2) was assessed using regression modeling, controlling for demographic and health history variables. Results Of the 2,196 patients with FM, 11.2% reported no sleep difficulty symptoms, 25.7% reported one sleep difficulty symptom, and 63.05% reported two or more sleep difficulty symptoms. The prevalence of sleep difficulty symptoms was significantly higher than matched controls. Patients with one and two sleep difficulty symptoms both reported significantly worse HRQoL summary and domain scores relative to those with no sleep difficulty symptoms (all p<.05). Further, the relationship between sleep difficulty symptoms and HRQoL was significantly different between those with FM than matched controls, suggesting a uniqueness of the burden of sleep difficulties within the FM population. Conclusions Among the FM population, sleep difficulty symptoms were independently associated with clinically-meaningful decrements in mental and physical HRQoL. These results suggest that greater emphasis in the treatment of sleep difficulty symptoms among the FM population may be warranted. PMID:23072292

Comparative efficacy of switching to natalizumab in active multiple sclerosis

PubMed Central

Spelman, Timothy; Kalincik, Tomas; Zhang, Annie; Pellegrini, Fabio; Wiendl, Heinz; Kappos, Ludwig; Tsvetkova, Larisa; Belachew, Shibeshih; Hyde, Robert; Verheul, Freek; Grand-Maison, Francois; Izquierdo, Guillermo; Grammond, Pierre; Duquette, Pierre; Lugaresi, Alessandra; Lechner-Scott, Jeannette; Oreja-Guevara, Celia; Hupperts, Raymond; Petersen, Thor; Barnett, Michael; Trojano, Maria; Butzkueven, Helmut

2015-01-01

Objective To compare treatment efficacy and persistence in patients who switched to natalizumab versus those who switched between glatiramer acetate (GA) and interferon-beta (IFNβ) after an on-treatment relapse on IFNβ or GA using propensity score matched real-world datasets. Methods Patients included were registered in MSBase or the TYSABRI Observational Program (TOP), had relapsed on IFNβ or GA within 12 months prior to switching to another therapy, and had initiated natalizumab or IFNβ/GA treatment ≤6 months after discontinuing prior therapy. Covariates were balanced across post switch treatment groups by propensity score matching at treatment initiation. Relapse, persistence, and disability measures were compared between matched treatment arms in the total population (n = 869/group) and in subgroups defined by prior treatment history (IFNβ only [n = 578/group], GA only [n = 165/group], or both IFNβ and GA [n = 176/group]). Results Compared to switching between IFNβ and GA, switching to natalizumab reduced annualized relapse rate in year one by 65–75%, the risk of first relapse by 53–82% (mean follow-up 1.7–2.2 years) and treatment discontinuation events by 48–65% (all P ≤ 0.001). In the total population, switching to natalizumab reduced the risk of confirmed disability progression by 26% (P = 0.036) and decreased the total disability burden by 1.54 EDSS-years (P < 0.0001) over the first 24 months post switch. Interpretation Using large, real-world, propensity-matched datasets we demonstrate that after a relapse on IFNβ or GA, switching to natalizumab (rather than between IFNβ and GA) led to superior outcomes for patients in all measures assessed. Results were consistent regardless of the prior treatment identity. PMID:25909083

Does a Rater's Professional Background Influence Communication Skills Assessment?

PubMed

Artemiou, Elpida; Hecker, Kent G; Adams, Cindy L; Coe, Jason B

2015-01-01

There is increasing pressure in veterinary education to teach and assess communication skills, with the Objective Structured Clinical Examination (OSCE) being the most common assessment method. Previous research reveals that raters are a large source of variance in OSCEs. This study focused on examining the effect of raters' professional background as a source of variance when assessing students' communication skills. Twenty-three raters were categorized according to their professional background: clinical sciences (n=11), basic sciences (n=4), clinical communication (n=5), or hospital administrator/clinical skills technicians (n=3). Raters from each professional background were assigned to the same station and assessed the same students during two four-station OSCEs. Students were in year 2 of their pre-clinical program. Repeated-measures ANOVA results showed that OSCE scores awarded by the rater groups differed significantly: (F(matched_station_1) [2,91]=6.97, p=.002), (F(matched_station_2) [3,90]=13.95, p=.001), (F(matched_station_3) [3,90]=8.76, p=.001), and ((Fmatched_station_4) [2,91]=30.60, p=.001). A significant time effect between the two OSCEs was calculated for matched stations 1, 2, and 4, indicating improved student performances. Raters with a clinical communication skills background assigned scores that were significantly lower compared to the other rater groups. Analysis of written feedback provided by the clinical sciences raters showed that they were influenced by the students' clinical knowledge of the case and that they did not rely solely on the communication checklist items. This study shows that it is important to consider rater background both in recruitment and training programs for communication skills' assessment.

Prevalence by Computed Tomographic Angiography of Coronary Plaques in South Asian and White Patients With Type 2 Diabetes Mellitus at Low and High Risk Using Four Cardiovascular Risk Scores (UKPDS, FRS, ASCVD, and JBS3).

PubMed

Gobardhan, Sanjay N; Dimitriu-Leen, Aukelien C; van Rosendael, Alexander R; van Zwet, Erik W; Roos, Cornelis J; Oemrawsingh, Pranobe V; Kharagjitsingh, Aan V; Jukema, J Wouter; Delgado, Victoria; Schalij, Martin J; Bax, Jeroen J; Scholte, Arthur J H A

2017-03-01

The aim of this study was to explore the association between various cardiovascular (CV) risk scores and coronary atherosclerotic burden on coronary computed tomography angiography (CTA) in South Asians with type 2 diabetes mellitus and matched whites. Asymptomatic type 2 diabetic South Asians and whites were matched for age, gender, body mass index, hypertension, and hypercholesterolemia. Ten-year CV risk was estimated using different risk scores (United Kingdom Prospective Diabetes Study [UKPDS], Framingham Risk Score [FRS], AtheroSclerotic CardioVascular Disease [ASCVD], and Joint British Societies for the prevention of CVD [JBS3]) and categorized into low- and high-risk groups. The presence of coronary artery calcium (CAC) and obstructive coronary artery disease (CAD; ≥50% stenosis) was assessed using coronary CTA. Finally, the relation between coronary atherosclerosis on CTA and the low- and high-risk groups was compared. UKPDS, FRS, and ASCVD showed no differences in estimated CV risk between 159 South Asians and 159 matched whites. JBS3 showed a significant greater absolute CV risk in South Asians (18.4% vs 14.2%, p <0.01). Higher presence of CAC score >0 (69% vs 55%, p <0.05) and obstructive CAD (39% vs 27%, p <0.05) was observed in South Asians. South Asians categorized as high risk, using UKPDS, FRS, and ASCVD, showed more CAC and CAD compared than whites. JBS3 showed no differences. In conclusion, asymptomatic South Asians with type 2 diabetes mellitus more frequently showed CAC and obstructive CAD than matched whites in the population categorized as high-risk patients using UKPDS, FRS, and ASCVD as risk estimators. However, JBS3 seems to correlate best to CAC and CAD in both ethnicity groups compared with the other risk scores. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of alcohol use on mortality and expenditure during hospital admission: a cross-sectional study

PubMed Central

Peng, Shu-Hui; Hsu, Shiun-Yuan; Kuo, Pao-Jen; Rau, Cheng-Shyuan; Cheng, Ya-Ai; Hsieh, Ching-Hua

2016-01-01

Objectives This study was designed to investigate the effect of alcohol intoxication on clinical presentation of hospitalised adult trauma patients at a Level I trauma centre using propensity score matching. Design Cross-sectional study. Setting Taiwan. Participants Detailed data of 929 hospitalised adult trauma patients with alcohol intoxication, aged 20–65 years, and 10 104 corresponding patients without alcohol intoxication were retrieved from the Trauma Registry System between 1 January 2009 and 31 December 2014. Alcohol intoxication was defined as a blood alcohol concentration (BAC) ≥50 mg/dL. Main outcome measures In-hospital mortality and expenditure. Results Patients with alcohol intoxication presented with significantly higher short-term mortality (OR: 3.0, 95% CI 2.0 to 4.4; p<0.001) than patients without alcohol intoxication. However, on comparison with propensity score-matched patients with respect to sex, age, comorbidity, Glasgow Coma Scale (GCS), injury region based on Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS), alcohol intoxication did not significantly influence mortality (OR: 0.8, 95% CI 0.5 to 1.4; p=0.563). This implied that the higher mortality of alcohol-intoxicated patients was attributable to patient characteristics such as a higher injury severity rather than alcohol intoxication. Even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication, patients with alcohol intoxication still had significantly higher total expenditure (17.4% higher), cost of operation (40.3% higher), cost of examination (52.8% higher) and cost of pharmaceuticals (38.3% higher). Conclusions The associated higher mortality of adult trauma patients with alcohol intoxication was completely attributable to other patient characteristics and associated injury severity rather than the effects of alcohol. However, patients with alcohol intoxication incurred significantly higher expenditure than patients without alcohol intoxication, even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication. PMID:27803110

Propensity score matching for selection of local areas as controls for evaluation of effects of alcohol policies in case series and quasi case-control designs.

PubMed

de Vocht, F; Campbell, R; Brennan, A; Mooney, J; Angus, C; Hickman, M

2016-03-01

Area-level public health interventions can be difficult to evaluate using natural experiments. We describe the use of propensity score matching (PSM) to select control local authority areas (LAU) to evaluate the public health impact of alcohol policies for (1) prospective evaluation of alcohol policies using area-level data, and (2) a novel two-stage quasi case-control design. Ecological. Alcohol-related indicator data (Local Alcohol Profiles for England, PHE Health Profiles and ONS data) were linked at LAU level. Six LAUs (Blackpool, Bradford, Bristol, Ipswich, Islington, and Newcastle-upon-Tyne) as sample intervention or case areas were matched to two control LAUs each using PSM. For the quasi case-control study a second stage was added aimed at obtaining maximum contrast in outcomes based on propensity scores. Matching was evaluated based on average standardized absolute mean differences (ASAM) and variable-specific P-values after matching. The six LAUs were matched to suitable control areas (with ASAM < 0.20, P-values >0.05 indicating good matching) for a prospective evaluation study that sought areas that were similar at baseline in order to assess whether a change in intervention exposure led to a change in the outcome (alcohol related harm). PSM also generated appropriate matches for a quasi case-control study--whereby the contrast in health outcomes between cases and control areas needed to be optimized in order to assess retrospectively whether differences in intervention exposure were associated with the outcome. The use of PSM for area-level alcohol policy evaluation, but also for other public health interventions, will improve the value of these evaluations by objective and quantitative selection of the most appropriate control areas. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Propensity Score Analytical Framework: An Overview and Institutional Research Example

ERIC Educational Resources Information Center

Herzog, Serge

2014-01-01

Estimating the effect of campus math tutoring support, this study demonstrates the use of propensity score weighted and matched-data analysis and examines the correspondence with results from parametric regression analysis.

Lean-Season Food Transfers Affect Children's Diets and Household Food Security: Evidence from a Quasi-Experiment in Malawi.

PubMed

Gelli, Aulo; Aberman, Noora-Lisa; Margolies, Amy; Santacroce, Marco; Baulch, Bob; Chirwa, Ephraim

2017-05-01

Background: There is evidence that social transfers increase food consumption, improving the quantity and quality of food consumed by poor households. Questions remain on how to improve the effectiveness of social programs. Objective: The aim was to assess the impact of a lean-season food transfer on household food security, diet, and nutrition status of young children during the lean season in Malawi and to understand processes through which transfers operated. Methods: This was a longitudinal, quasi-experimental study based on 2 survey rounds in the Zomba district in Malawi. Data were collected from 60 communities randomly selected among food-insecure villages. Twenty households were randomly selected for interviews within each community. Study outcomes included household expenditures and food consumption (measured by using 7-d recall) and child-level dietary diversity (measured by using 24-h recall) and nutritional status (anthropometric measurements). We followed a mixed-methods approach involving child- and household-level assessments, as well as interviews with community stakeholders. We estimated program impact by combining propensity score matching and difference-in-difference methods. Results: The per capita effect of food transfers on food expenditure was estimated at 36 Malawian kwachas/d, corresponding to an increase of 19% from baseline. There was evidence of increased iron availability in household intake. Highly significant effects were found on children's dietary diversity score, corresponding to an increase of 15%, as well as a positive effect on weight-for-height z scores (WHZs) of >0.25 SDs. Effects on food expenditure and dietary diversity were robust to alternative matching specifications, although the effect on WHZs was not. Examination of the targeting of the transfer showed evidence of large errors of inclusion and exclusion. Conclusion: During the lean season in food-insecure settings, where important declines in food insecurity, diet quality, and nutrition status are present, food transfers may have a protective effect on household food security and diets of young children. © 2017 American Society for Nutrition.

Tempest: GPU-CPU computing for high-throughput database spectral matching.

PubMed

Milloy, Jeffrey A; Faherty, Brendan K; Gerber, Scott A

2012-07-06

Modern mass spectrometers are now capable of producing hundreds of thousands of tandem (MS/MS) spectra per experiment, making the translation of these fragmentation spectra into peptide matches a common bottleneck in proteomics research. When coupled with experimental designs that enrich for post-translational modifications such as phosphorylation and/or include isotopically labeled amino acids for quantification, additional burdens are placed on this computational infrastructure by shotgun sequencing. To address this issue, we have developed a new database searching program that utilizes the massively parallel compute capabilities of a graphical processing unit (GPU) to produce peptide spectral matches in a very high throughput fashion. Our program, named Tempest, combines efficient database digestion and MS/MS spectral indexing on a CPU with fast similarity scoring on a GPU. In our implementation, the entire similarity score, including the generation of full theoretical peptide candidate fragmentation spectra and its comparison to experimental spectra, is conducted on the GPU. Although Tempest uses the classical SEQUEST XCorr score as a primary metric for evaluating similarity for spectra collected at unit resolution, we have developed a new "Accelerated Score" for MS/MS spectra collected at high resolution that is based on a computationally inexpensive dot product but exhibits scoring accuracy similar to that of the classical XCorr. In our experience, Tempest provides compute-cluster level performance in an affordable desktop computer.

Possibility of spoof attack against robustness of multibiometric authentication systems

NASA Astrophysics Data System (ADS)

Hariri, Mahdi; Shokouhi, Shahriar Baradaran

2011-07-01

Multibiometric systems have been recently developed in order to overcome some weaknesses of single biometric authentication systems, but security of these systems against spoofing has not received enough attention. In this paper, we propose a novel practical method for simulation of possibilities of spoof attacks against a biometric authentication system. Using this method, we model matching scores from standard to completely spoofed genuine samples. Sum, product, and Bayes fusion rules are applied for score level combination. The security of multimodal authentication systems are examined and compared with the single systems against various spoof possibilities. However, vulnerability of fused systems is considerably increased against spoofing, but their robustness is generally higher than single matcher systems. In this paper we show that robustness of a combined system is not always higher than a single system against spoof attack. We propose empirical methods for upgrading the security of multibiometric systems, which contain how to organize and select biometric traits and matchers against various possibilities of spoof attack. These methods provide considerable robustness and present an appropriate reason for using combined systems against spoof attacks.

Peer Victimization and Sexual Risk Differences Between Lesbian, Gay, Bisexual, Transgender, or Questioning and Nontransgender Heterosexual Youths in Grades 7–12

PubMed Central

Espelage, Dorothy L.

2013-01-01

Objectives. Before and after accounting for peer victimization, we estimated sexual risk disparities between students who self-identified as lesbian, gay, bisexual, transgender, or questioning (LGBTQ) and students who self-identified as nontransgender heterosexual. Methods. Students in grades 7 through 12 in Dane County, Wisconsin, were given the Web-administered Dane County Youth Assessment. One set of analyses was based on a sample that included 11 337 students. Subsequent analyses were based on a sample from which we screened out students who may not have been responding to survey items truthfully. Various multilevel-modeling and propensity-score-matching strategies ensured robustness of the results, examined disparities at lower and higher victimization rates, and explored heterogeneity among LGBTQ-identified youths. Finally, propensity-score-matching strategies estimated LGBTQ–heterosexual disparities in 2 matched samples: a sample that reported higher victimization and one that reported lower victimization. Results. Across 7 sexual risk outcomes, and in middle and high school, LGBTQ-identified youths reported engaging in riskier behavior than did heterosexual-identified youths after we accounted for peer victimization. Risk differentials were present in middle and high school. The LGBTQ group was heterogeneous, with lesbian/gay- and bisexual-identified youths generally appearing most risky, and questioning-identified youths least risky. In the matched sample with lower average victimization rates, LGBTQ-identified youths perceived a greater risk of sexually transmitted infections despite not engaging in sexually risky behavior at significantly higher rates; in the matched sample with higher average victimization rates, all outcomes were significantly different. Conclusions. Demonstrated LGBTQ–heterosexual risk differentials in grades 7 through 8 suggest that interventions need to be implemented during middle school. These interventions should also be differentiated to address the unique risk patterns among LGBTQ subgroups. Finally, models of sexual risk disparities must expand beyond peer victimization. PMID:23947999

How enhanced molecular ions in Cold EI improve compound identification by the NIST library.

PubMed

Alon, Tal; Amirav, Aviv

2015-12-15

Library-based compound identification with electron ionization (EI) mass spectrometry (MS) is a well-established identification method which provides the names and structures of sample compounds up to the isomer level. The library (such as NIST) search algorithm compares different EI mass spectra in the library's database with the measured EI mass spectrum, assigning each of them a similarity score called 'Match' and an overall identification probability. Cold EI, electron ionization of vibrationally cold molecules in supersonic molecular beams, provides mass spectra with all the standard EI fragment ions combined with enhanced Molecular Ions and high-mass fragments. As a result, Cold EI mass spectra differ from those provided by standard EI and tend to yield lower matching scores. However, in most cases, library identification actually improves with Cold EI, as library identification probabilities for the correct library mass spectra increase, despite the lower matching factors. This research examined the way that enhanced molecular ion abundances affect library identification probability and the way that Cold EI mass spectra, which include enhanced molecular ions and high-mass fragment ions, typically improve library identification results. It involved several computer simulations, which incrementally modified the relative abundances of the various ions and analyzed the resulting mass spectra. The simulation results support previous measurements, showing that while enhanced molecular ion and high-mass fragment ions lower the matching factor of the correct library compound, the matching factors of the incorrect library candidates are lowered even more, resulting in a rise in the identification probability for the correct compound. This behavior which was previously observed by analyzing Cold EI mass spectra can be explained by the fact that high-mass ions, and especially the molecular ion, characterize a compound more than low-mass ions and therefore carries more weight in library search identification algorithms. These ions are uniquely abundant in Cold EI, which therefore enables enhanced compound characterization along with improved NIST library based identification. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of incorporating low intensity exercise into the recovery period after a rugby match.

PubMed

Suzuki, M; Umeda, T; Nakaji, S; Shimoyama, T; Mashiko, T; Sugawara, K

2004-08-01

The psychological and physiological condition of athletes affect both their performance in competitions and their health. Rugby is an intense sport which appears to impose psychological and physiological stress on players. However, there have been few studies of the most appropriate resting techniques to deliver effective recovery from a match. To compare the difference in recovery after a match using resting techniques with or without exercise. Fifteen Japanese college rugby football players were studied. Seven performed only normal daily activities and eight performed additional low intensity exercise during the post-match rest period. Players were examined just before and immediately after the match and one and two days after the match. Blood biochemistry and two neutrophil functions, phagocytic activity and oxidative burst, were measured to assess physiological condition, and the profile of mood states (POMS) scores were examined to evaluate psychological condition. Immediately after the match, muscle damage, decreases in neutrophil functions, and mental fatigue were observed in both groups. Muscle damage and neutrophil functions recovered with time almost equally in the two groups, but the POMS scores were significantly decreased only in subjects in the low intensity exercise group. Rugby matches impose both physiological and psychological stress on players. The addition of low intensity exercise to the rest period did not adversely affect physiological recovery and had a significantly beneficial effect on psychological recovery by enhancing relaxation.

Matching mammographic regions in mediolateral oblique and cranio caudal views: a probabilistic approach

NASA Astrophysics Data System (ADS)

Samulski, Maurice; Karssemeijer, Nico

2008-03-01

Most of the current CAD systems detect suspicious mass regions independently in single views. In this paper we present a method to match corresponding regions in mediolateral oblique (MLO) and craniocaudal (CC) mammographic views of the breast. For every possible combination of mass regions in the MLO view and CC view, a number of features are computed, such as the difference in distance of a region to the nipple, a texture similarity measure, the gray scale correlation and the likelihood of malignancy of both regions computed by single-view analysis. In previous research, Linear Discriminant Analysis was used to discriminate between correct and incorrect links. In this paper we investigate if the performance can be improved by employing a statistical method in which four classes are distinguished. These four classes are defined by the combinations of view (MLO/CC) and pathology (TP/FP) labels. We use distance-weighted k-Nearest Neighbor density estimation to estimate the likelihood of a region combination. Next, a correspondence score is calculated as the likelihood that the region combination is a TP-TP link. The method was tested on 412 cases with a malignant lesion visible in at least one of the views. In 82.4% of the cases a correct link could be established between the TP detections in both views. In future work, we will use the framework presented here to develop a context dependent region matching scheme, which takes the number and likelihood of possible alternatives into account. It is expected that more accurate determination of matching probabilities will lead to improved CAD performance.

Performance of biometric quality measures.

PubMed

Grother, Patrick; Tabassi, Elham

2007-04-01

We document methods for the quantitative evaluation of systems that produce a scalar summary of a biometric sample's quality. We are motivated by a need to test claims that quality measures are predictive of matching performance. We regard a quality measurement algorithm as a black box that converts an input sample to an output scalar. We evaluate it by quantifying the association between those values and observed matching results. We advance detection error trade-off and error versus reject characteristics as metrics for the comparative evaluation of sample quality measurement algorithms. We proceed this with a definition of sample quality, a description of the operational use of quality measures. We emphasize the performance goal by including a procedure for annotating the samples of a reference corpus with quality values derived from empirical recognition scores.

Short-Term Effects of Grade Retention on the Growth Rate of Woodcock-Johnson III Broad Math and Reading Scores

PubMed Central

Wu, Wei; West, Stephen G.; Hughes, Jan N.

2008-01-01

We investigated the effects of grade retention in first grade on the growth of the Woodcock-Johnson broad mathematics and reading scores over three years using linear growth curve modeling on an academically at-risk sample. A large sample (n = 784) of first grade children who were at risk for retention were initially identified based on low literacy scores. Scores representing propensity for retention were constructed based on 72 variables collected in comprehensive baseline testing in first grade. We closely matched 97 pairs of retained and promoted children based on their propensity scores using optimal matching procedures. This procedure adjusted for baseline differences between the retained and promoted children. We found that grade retention decreased the growth rate of mathematical skills but had no significant effect on reading skills. In addition, several potential moderators of the effect of retention on growth of mathematical and reading skills were identified including limited English language proficiency and children's conduct problems. PMID:19083352

Short-term effects of grade retention on the growth rate of Woodcock-Johnson III broad math and reading scores.

PubMed

Wu, Wei; West, Stephen G; Hughes, Jan N

2008-02-01

We investigated the effects of grade retention in first grade on the growth of the Woodcock-Johnson broad mathematics and reading scores over three years using linear growth curve modeling on an academically at-risk sample. A large sample (n=784) of first grade children who were at risk for retention was initially identified based on low literacy scores. Scores representing propensity for retention were constructed based on 72 variables collected in comprehensive baseline testing in first grade. We closely matched 97 pairs of retained and promoted children based on their propensity scores using optimal matching procedures. This procedure adjusted for baseline differences between the retained and promoted children. We found that grade retention decreased the growth rate of mathematical skills but had no significant effect on reading skills. In addition, several potential moderators of the effect of retention on growth of mathematical and reading skills were identified including limited English language proficiency and children's conduct problems.

Comparison and Limitations of DVH-Based NTCP Models Derived From 3D-CRT and IMRT Data for Prediction of Gastrointestinal Toxicities in Prostate Cancer Patients by Using Propensity Score Matched Pair Analysis

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

Troeller, Almut; Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-Universität, Munich; Yan, Di, E-mail: dyan@beaumont.edu

2015-02-01

Purpose: This study compared normal tissue complication probability (NTCP) modeling of chronic gastrointestinal toxicities following prostate cancer treatment for 2 treatment modalities. Possible factors causing discrepancies in optimal NTCP model parameters between 3-dimensional conformal radiation therapy (3D-CRT) and intensity modulated RT (IMRT) were analyzed and discussed, including the impact of patient characteristics, image guidance, toxicity scoring bias, and NTCP model limitations. Methods and Materials: Rectal wall dose-volume histograms of 1115 patients treated for prostate cancer under an adaptive radiation therapy protocol were used to model gastrointestinal toxicity grade ≥2 (according to Common Terminology Criteria for Adverse Events). A total ofmore » 457 patients were treated with 3D-CRT and 658 with IMRT. 3D-CRT patients were matched to IMRT patients based on various patient characteristics, using a propensity score–based algorithm. Parameters of the Lyman equivalent uniform dose and cut-off dose logistic regression NTCP models were estimated for the 2 matched treatment modalities and the combined group. Results: After they were matched, the 3D-CRT and IMRT groups contained 275 and 550 patients with a large discrepancy of 28.7% versus 7.8% toxicities, respectively (P<.001). For both NTCP models, optimal parameters found for the 3D-CRT groups did not fit the IMRT patients well and vice versa. Models developed for the combined data overestimated NTCP for the IMRT patients and underestimated NTCP for the 3D-CRT group. Conclusions: Our analysis did not reveal a single definitive cause for discrepancies of model parameters between 3D-CRT and IMRT. Patient characteristics and bias in toxicity scoring, as well as image guidance alone, are unlikely causes of the large discrepancy of toxicities. Whether the cause was inherent to the specific NTCP models used in this study needs to be verified by future investigations. Because IMRT is increasingly used clinically, it is important that appropriate NTCP model parameters are determined for this treatment modality.« less

[Revascularization of left anterior descending artery area using a skeletonized left internal mammary artery: a comparison between sequential and separate grafting].

PubMed

Shen, J Q; Ji, Q; Ding, W J; Xia, L M; Wei, L; Wang, C S

2018-03-13

Objective: To evaluate in-hospital and mid-term outcomes of sequential versus separate grafting of in situ skeletonized left internal mammary artery (LIMA) to the left coronary system in a single-center, propensity-matched study. Methods: After propensity score matching, 120 pairs of patients undergoing first, scheduled, isolated coronary artery bypass grafting (CABG) with in situ skeletonized LIMA grafting to the left anterior descending artery (LAD) territory were entered into a sequential group (sequential grafting of LIMA to the diagonal artery and then to the LAD) or a control group (separate grafting of LIMA to the LAD). The in-hospital and follow-up clinical outcomes and follow-up LIMA graft patency were compared. Results: The two propensity score-matched groups had similar in-hospital and follow-up clinical outcomes. The number of bypass conduits ranged from 3 to 6 (with a mean of 3.5), and 91.3%(219/240)of the included patients received off-pump CABG surgery. No significant differences were found between the two propensity score-matched groups in the in-hospital outcomes, including in-hospital death and the incidence of complications associated with CABG (prolonged ventilation, peroperative stroke, re-operation before discharge, and deep sternal wound infection). During follow-up, 9 patients (4 patients from the sequential group and 5 patients from the control group) died, and the all-cause mortality rate was 3.9%. No significant difference was found in the all-cause mortality rate between the 2 groups[3.4% (4/116) vs 4.3% (5/115), P =0.748]. During follow-up period, 99.1% (115/116) patency for the diagonal site and 98.3% (114/116) for the LAD site were determined by coronary computed tomographic angiography after sequential LIMA grafting, both of which were similar with graft patency of separate grafting of in situ skeletonized LIMA to the LAD. Conclusions: Revascularization of the left coronary system using a skeletonized LIMA resulted in excellent in-hospital and mid-term clinical outcomes and graft patency using sequential grafting.

Protection Orders Protect Against Assault and Injury: A Longitudinal Study of Police-Involved Women Victims of Intimate Partner Violence

PubMed Central

Kothari, Catherine L.; Rhodes, Karin V.; Wiley, James A.; Fink, Jeffrey; Overholt, Scott; Dichter, Melissa E.; Marcus, Steven C.; Cerulli, Catherine

2014-01-01

Objective To measure the efficacy of protection orders (POs) in reducing assault and injury-related outcomes using a matched comparison group and tracking outcomes over time. Methods This study was a retrospective review of police, emergency department, family court and prosecutor administrative records for a cohort of police-involved female IPV victims; all events over a four-year study period were abstracted. Victims who obtained protection orders (POs) were compared to a propensity-score-based match group without POs over three time periods: Before, during, and after the issuance of a PO. Results Having a PO in place was associated with significantly more calls to police for non-assaultive incidents, and more police charging requests that were multiple-count and felony-level. Comparing outcomes, PO victims had police incident rates that were more than double the matched group prior to the PO, but dropped to the level of the matched group during and after the order. ED visits dropped over time for both groups. Conclusion This study confirmed the protective effect of POs, which are associated with reduced police incidents and emergency department visits both during and after the order, and reduced police incidents compared to a matched comparison group. PMID:22491224

Mixture-Tuned, Clutter Matched Filter for Remote Detection of Subpixel Spectral Signals

NASA Technical Reports Server (NTRS)

Thompson, David R.; Mandrake, Lukas; Green, Robert O.

2013-01-01

Mapping localized spectral features in large images demands sensitive and robust detection algorithms. Two aspects of large images that can harm matched-filter detection performance are addressed simultaneously. First, multimodal backgrounds may thwart the typical Gaussian model. Second, outlier features can trigger false detections from large projections onto the target vector. Two state-of-the-art approaches are combined that independently address outlier false positives and multimodal backgrounds. The background clustering models multimodal backgrounds, and the mixture tuned matched filter (MT-MF) addresses outliers. Combining the two methods captures significant additional performance benefits. The resulting mixture tuned clutter matched filter (MT-CMF) shows effective performance on simulated and airborne datasets. The classical MNF transform was applied, followed by k-means clustering. Then, each cluster s mean, covariance, and the corresponding eigenvalues were estimated. This yields a cluster-specific matched filter estimate as well as a cluster- specific feasibility score to flag outlier false positives. The technology described is a proof of concept that may be employed in future target detection and mapping applications for remote imaging spectrometers. It is of most direct relevance to JPL proposals for airborne and orbital hyperspectral instruments. Applications include subpixel target detection in hyperspectral scenes for military surveillance. Earth science applications include mineralogical mapping, species discrimination for ecosystem health monitoring, and land use classification.

Post-decomposition optimizations using pattern matching and rule-based clustering for multi-patterning technology

NASA Astrophysics Data System (ADS)

Wang, Lynn T.-N.; Madhavan, Sriram

2018-03-01

A pattern matching and rule-based polygon clustering methodology with DFM scoring is proposed to detect decomposition-induced manufacturability detractors and fix the layout designs prior to manufacturing. A pattern matcher scans the layout for pre-characterized patterns from a library. If a pattern were detected, rule-based clustering identifies the neighboring polygons that interact with those captured by the pattern. Then, DFM scores are computed for the possible layout fixes: the fix with the best score is applied. The proposed methodology was applied to two 20nm products with a chip area of 11 mm2 on the metal 2 layer. All the hotspots were resolved. The number of DFM spacing violations decreased by 7-15%.

Modular and configurable optimal sequence alignment software: Cola.

PubMed

Zamani, Neda; Sundström, Görel; Höppner, Marc P; Grabherr, Manfred G

2014-01-01

The fundamental challenge in optimally aligning homologous sequences is to define a scoring scheme that best reflects the underlying biological processes. Maximising the overall number of matches in the alignment does not always reflect the patterns by which nucleotides mutate. Efficiently implemented algorithms that can be parameterised to accommodate more complex non-linear scoring schemes are thus desirable. We present Cola, alignment software that implements different optimal alignment algorithms, also allowing for scoring contiguous matches of nucleotides in a nonlinear manner. The latter places more emphasis on short, highly conserved motifs, and less on the surrounding nucleotides, which can be more diverged. To illustrate the differences, we report results from aligning 14,100 sequences from 3' untranslated regions of human genes to 25 of their mammalian counterparts, where we found that a nonlinear scoring scheme is more consistent than a linear scheme in detecting short, conserved motifs. Cola is freely available under LPGL from https://github.com/nedaz/cola.

Microorganism Identification Based On MALDI-TOF-MS Fingerprints

NASA Astrophysics Data System (ADS)

Elssner, Thomas; Kostrzewa, Markus; Maier, Thomas; Kruppa, Gary

Advances in MALDI-TOF mass spectrometry have enabled the ­development of a rapid, accurate and specific method for the identification of bacteria directly from colonies picked from culture plates, which we have named the MALDI Biotyper. The picked colonies are placed on a target plate, a drop of matrix solution is added, and a pattern of protein molecular weights and intensities, "the protein fingerprint" of the bacteria, is produced by the MALDI-TOF mass spectrometer. The obtained protein mass fingerprint representing a molecular signature of the microorganism is then matched against a database containing a library of previously measured protein mass fingerprints, and scores for the match to every library entry are produced. An ID is obtained if a score is returned over a pre-set threshold. The sensitivity of the techniques is such that only approximately 104 bacterial cells are needed, meaning that an overnight culture is sufficient, and the results are obtained in minutes after culture. The improvement in time to result over biochemical methods, and the capability to perform a non-targeted identification of bacteria and spores, potentially makes this method suitable for use in the detect-to-treat timeframe in a bioterrorism event. In the case of white-powder samples, the infectious spore is present in sufficient quantity in the powder so that the MALDI Biotyper result can be obtained directly from the white powder, without the need for culture. While spores produce very different patterns from the vegetative colonies of the corresponding bacteria, this problem is overcome by simply including protein fingerprints of the spores in the library. Results on spores can be returned within minutes, making the method suitable for use in the "detect-to-protect" timeframe.

Mineralocorticoid receptor antagonists for heart failure: a real‐life observational study

PubMed Central

Bruno, Noemi; Sinagra, Gianfranco; Paolillo, Stefania; Bonomi, Alice; Corrà, Ugo; Piepoli, Massimo; Veglia, Fabrizio; Salvioni, Elisabetta; Lagioia, Rocco; Metra, Marco; Limongelli, Giuseppe; Cattadori, Gaia; Scardovi, Angela B.; Carubelli, Valentina; Scrutino, Domenico; Badagliacca, Roberto; Guazzi, Marco; Raimondo, Rosa; Gentile, Piero; Magrì, Damiano; Correale, Michele; Parati, Gianfranco; Re, Federica; Cicoira, Mariantonietta; Frigerio, Maria; Bussotti, Maurizio; Vignati, Carlo; Oliva, Fabrizio; Mezzani, Alessandro; Vergaro, Giuseppe; Di Lenarda, Andrea; Passino, Claudio; Sciomer, Susanna; Pacileo, Giuseppe; Ricci, Roberto; Contini, Mauro; Apostolo, Anna; Palermo, Pietro; Mapelli, Massimo; Carriere, Cosimo; Clemenza, Francesco; Binno, Simone; Belardinelli, Romualdo; Lombardi, Carlo; Perrone Filardi, Pasquale; Emdin, Michele

2018-01-01

Abstract Aims Mineralocorticoid receptor antagonists (MRAs) have been demonstrated to improve outcomes in reduced ejection fraction heart failure (HFrEF) patients. However, MRAs added to conventional treatment may lead to worsening of renal function and hyperkalaemia. We investigated, in a population‐based analysis, the long‐term effects of MRA treatment in HFrEF patients. Methods and results We analysed data of 6046 patients included in the Metabolic Exercise Cardiac Kidney Index score dataset. Analysis was performed in patients treated (n = 3163) and not treated (n = 2883) with MRA. The study endpoint was a composite of cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation. Ten years' survival was analysed through Kaplan–Meier, compared by log‐rank test and propensity score matching. At 10 years' follow‐up, the MRA‐untreated group had a significantly lower number of events than the MRA‐treated group (P < 0.001). MRA‐treated patients had more severe heart failure (higher New York Heart Association class and lower left ventricular ejection fraction, kidney function, and peak VO2). At a propensity‐score‐matching analysis performed on 1587 patients, MRA‐treated and MRA‐untreated patients showed similar study endpoint values. Conclusions In conclusion, MRA treatment does not affect the composite of cardiovascular death, urgent heart transplantation or left ventricular assist device implantation in a real‐life setting. A meticulous patient follow‐up, as performed in trials, is likely needed to match the positive MRA‐related benefits observed in clinical trials. PMID:29397584

On pump versus off pump coronary artery bypass grafting in patients with end-stage renal disease and coronary artery disease - A nation-wide, propensity score matched database analyses.

PubMed

Chen, Jien-Jiun; Lin, Lian-Yu; Yang, Yao-Hsu; Hwang, Juey-Jen; Chen, Pau-Chung; Lin, Jiunn-Lee; Chi, Nai-Hsin

2017-01-15

The usage of on or off cardiopulmonary bypass in patients with coronary artery disease receiving coronary artery bypass grafting (CABG) surgery had been debated and had not yet been investigated thoroughly in patients with end-stage renal disease (ESRD). We aimed to study cardiovascular outcomes and total mortality in these patients by using our National Health Insurance (NHI) database. By using our NHI ESRD claim database, we searched ESRD patients aged more than 18years, who received CABG and divided them into on pump and off pump groups. Baseline characteristics and underlying comorbidities were identified from the database. Propensity score (PS) method was used to match all the potential confounders between patients. Outcomes including mortality, myocardial infarction, stroke and repeat revascularization within 30days, 1year and whole follow-up period were also obtained. A total of 134,410 ESRD patients were identified in the database. We included 341 patients and 543 patients who received off pump and on pump CABG respectively. The hazard ratios of different outcomes at 30days, 1year and a median of 745days after CABG did not show significant different between on, or off pump groups before and after PS match. ESRD patients with CAD undergoing either on pump or off pump CABG surgery showed similar outcomes in 30days, 1year and whole follow-up period. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A novel algorithm for validating peptide identification from a shotgun proteomics search engine.

PubMed

Jian, Ling; Niu, Xinnan; Xia, Zhonghang; Samir, Parimal; Sumanasekera, Chiranthani; Mu, Zheng; Jennings, Jennifer L; Hoek, Kristen L; Allos, Tara; Howard, Leigh M; Edwards, Kathryn M; Weil, P Anthony; Link, Andrew J

2013-03-01

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has revolutionized the proteomics analysis of complexes, cells, and tissues. In a typical proteomic analysis, the tandem mass spectra from a LC-MS/MS experiment are assigned to a peptide by a search engine that compares the experimental MS/MS peptide data to theoretical peptide sequences in a protein database. The peptide spectra matches are then used to infer a list of identified proteins in the original sample. However, the search engines often fail to distinguish between correct and incorrect peptides assignments. In this study, we designed and implemented a novel algorithm called De-Noise to reduce the number of incorrect peptide matches and maximize the number of correct peptides at a fixed false discovery rate using a minimal number of scoring outputs from the SEQUEST search engine. The novel algorithm uses a three-step process: data cleaning, data refining through a SVM-based decision function, and a final data refining step based on proteolytic peptide patterns. Using proteomics data generated on different types of mass spectrometers, we optimized the De-Noise algorithm on the basis of the resolution and mass accuracy of the mass spectrometer employed in the LC-MS/MS experiment. Our results demonstrate De-Noise improves peptide identification compared to other methods used to process the peptide sequence matches assigned by SEQUEST. Because De-Noise uses a limited number of scoring attributes, it can be easily implemented with other search engines.

The economic burden of angina on households in South Asia

PubMed Central

2014-01-01

Background Globally, an estimated 54 million people have angina, 16 million of whom are from the WHO South-East Asia region. Despite the increasing burden of cardiovascular disease (CVD) in South Asia, there is no evidence of an economic burden of angina on households in this region. We investigated the economic burden of angina on households in South Asia. Methods We applied a novel propensity score matching approach to assess the economic burden of angina on household out-of-pocket (OOP) health spending, borrowing or selling assets, non-medical consumption expenditure, and employment status of angina-affected individual using nationally representative World Health Survey data from Bangladesh, India, Nepal and Sri Lanka collected during 2002-2003. We used multiple matching methods to match households where the respondent reported symptomatic or diagnosed angina with control households with similar propensity scores. Results Angina-affected households had significantly higher OOP health spending per person in the four weeks preceding the survey than matched controls, in Bangladesh (I$1.94, p = 0.04), in Nepal (I$4.68, p = 0.03) and in Sri Lanka (I$1.99, p < 0.01). Nearly half of this difference was accounted for by drug expenditures. Catastrophic spending, defined as the ratio of OOP health spending to total household expenditure in excess of 20%, was significantly higher in angina-affected households relative to matched controls in India (9.60%, p < 0.01), Nepal (4.90%, p = 0.02) and Sri Lanka (9.10%, p < 0.01). Angina-affected households significantly relied on borrowing or selling assets to finance OOP health expenses in Bangladesh (6%, p = 0.03), India (8.20%, p < 0.01) and Sri Lanka (7.80%, p = 0.01). However, impoverishment, non-medical consumption expenditure and employment status of the angina-affected individual remained mostly unaffected. We adjusted our estimates for comorbidities, but limitations on comorbidity data in the WHS mean that our results may be upwardly biased. Conclusions Households that had the respondent reporting angina in South Asia face an economic burden of OOP health expenses (primarily on drugs and other outpatient expenses), and tend to rely on borrowing or selling assets. Our analysis underscores the need to protect South Asian households from the financial burden of CVD. PMID:24548585

Effects of the body mass index (BMI) on the surgical outcomes of laparoscopic fundoplication for gastro-esophageal reflux disease: a propensity score-matched analysis.

PubMed

Hoshino, Masato; Omura, Nobuo; Yano, Fumiaki; Tsuboi, Kazuto; Yamamoto, Se Ryung; Akimoto, Shunsuke; Masuda, Takahiro; Kashiwagi, Hideyuki; Yanaga, Katsuhiko

2018-02-01

In the present study, we examined how the body mass index (BMI) affected the outcomes of laparoscopic fundoplication for GERD in patients, whose backgrounds were matched in a propensity score-matched analysis. We divided the patients into two groups (BMI <25 kg/m 2 and BMI ≥25 kg/m 2 ). The following background information was matched for the propensity score-matched analysis: sex, age, degree of esophageal hiatal hernia, acid exposure time, and degree of reflux esophagitis. In total, 105 subjects were extracted in each group. The surgical outcomes and postoperative outcomes of patients with BMI <25 kg/m 2 (Group A) and those with BMI ≥25 kg/m 2 (Group B) were compared and examined. There were no differences in the surgical procedure, intraoperative complications, or estimated blood loss (p = 0.876, p = 0.516, p = 0.438, respectively); however, the operative time was significantly prolonged in Group B (p = 0.003). The rate of postoperative recurrence in Group A was 17% (15/87 patients), while that in Group B was 11% (12/91 patients), and did not differ to a statistically significant extent (p = 0.533). Although the operative time for GERD in obese patients was prolonged in comparison with non-obese patients, there was no difference in the rate of postoperative recurrence.

Vitamin D deficiency in chronic idiopathic urticaria.

PubMed

Movahedi, Masoud; Tavakol, Marzieh; Hirbod-Mobarakeh, Armin; Gharagozlou, Mohammad; Aghamohammadi, Asghar; Tavakol, Zahra; Momenzadeh, Kaveh; Nabavi, Mohammad; Dabbaghzade, Abbas; Mosallanejad, Asieh; Rezaei, Nima

2015-04-01

Chronic urticaria is the most common skin diseases, characterized by chronic cutaneous lesions which severely debilitates patients in several aspects of their everyday life. Vitamin D is known to exert several actions in the immune system and to influence function and differentiation of mast cells, central role players in the pathogenesis of chronic idiopathic urticaria. This study was performed to evaluate the relationship between vitamin D levels and susceptibility to chronic idiopathic urticaria. One hundred and fourteen patients with chronic idiopathic urticaria were recruited in this study along with one hundred and eighty seven sex-matched and age-matched healthy volunteers as the control group. For each patient, urticaria activity score was calculated and autologous serum skin test was done. Vitamin D metabolic statue was measured in serum as 25 hydroxyvitamin D using enzyme immunoassay method. Patients with chronic idiopathic urticaria significantly showed lower levels of vitamin D. Vitamin D deficiency was significantly associated with increased susceptibility to chronic idiopathic urticaria. There was a significant positive correlation between vitamin D levels and urticaria activity score. This study showed that patients with chronic idiopathic urticaria had reduced levels of vitamin D, while vitamin D deficiency could increase susceptibility to chronic idiopathic urticaria.

PepPat, a pattern-based oligopeptide homology search method and the identification of a novel tachykinin-like peptide.

PubMed

Jiang, Ying; Gao, Ge; Fang, Gang; Gustafson, Eric L; Laverty, Maureen; Yin, Yanbin; Zhang, Yong; Luo, Jingchu; Greene, Jonathan R; Bayne, Marvin L; Hedrick, Joseph A; Murgolo, Nicholas J

2003-05-01

PepPat, a hybrid method that combines pattern matching with similarity scoring, is described. We also report PepPat's application in the identification of a novel tachykinin-like peptide. PepPat takes as input a query peptide and a user-specified regular expression pattern within the peptide. It first performs a database pattern match and then ranks candidates on the basis of their similarity to the query peptide. PepPat calculates similarity over the pattern spanning region, enhancing PepPat's sensitivity for short query peptides. PepPat can also search for a user-specified number of occurrences of a repeated pattern within the target sequence. We illustrate PepPat's application in short peptide ligand mining. As a validation example, we report the identification of a novel tachykinin-like peptide, C14TKL-1, and show it is an NK1 (neuokinin receptor 1) agonist whose message is widely expressed in human periphery. PepPat is offered online at: http://peppat.cbi.pku.edu.cn.

Outcomes of hip arthroscopy in patients aged 50 years or older compared with a matched-pair control of patients aged 30 years or younger.

PubMed

Domb, Benjamin G; Linder, Dror; Finley, Zachary; Botser, Itamar B; Chen, Austin; Williamson, Joseph; Gupta, Asheesh

2015-02-01

Age has been suggested as a negative prognostic factor for hip arthroscopy. The purpose of this study was to compare patient characteristics and outcomes after hip arthroscopy in patients aged 50 years or older with a matched control group of patients aged 30 years or younger at a minimum postoperative follow-up of 2 years. Between September 2008 and March 2010, data were prospectively collected on all patients aged 50 years or older undergoing primary hip arthroscopy. Fifty-two patients met our inclusion and matching criteria, of whom all 52 (100%) were available for follow-up at a minimum of 2 years. This cohort was compared with a matched-pair control group of patients aged 30 years or younger who underwent similar procedures. The mean age of the study group was 54.8 years (range, 50 to 69 years), and that of the control group was 20.3 years (range, 13 to 30 years). The groups were matched at a 1:1 ratio, including 18 male patients (34.6%) and 34 female patients (65.4%) in each group, with a mean follow-up period of 32 months (range, 24 to 54 months). In the younger control group, the score improvement from preoperatively to 2 years' follow-up was 62.9 to 84.2 for the modified Harris Hip Score, 60.5 to 84.2 for the Non-Arthritic Hip Score, 63.1 to 86.5 for the Hip Outcome Score-Activities of Daily Living, and 42.2 to 72.7 for the Hip Outcome Score-Sport-Specific Subscale. In the older study group, the score improvement from preoperatively to 2 years' follow-up was 61.2 to 82.2 for the modified Harris Hip Score, 59.9 to 80.4 for the Non-Arthritic Hip Score, 63.9 to 83 for the Hip Outcome Score-Activities of Daily Living, and 41.2 to 64.6 for the Hip Outcome Score-Sport-Specific Subscale. All improvements in both groups were statistically significant at the 2-year postoperative follow-up (P < .001). There was no significant difference for all patient-reported outcome (PRO) scores at final follow-up between both groups. When we compared the change in PRO scores (Δ) from preoperatively to 2 years postoperatively, there was no significant difference between both groups. The overall survivorship rate was 98.1% for the younger control group and 82.7% for the older study group. Survivors aged 50 years or older show similar improvement to patients aged 30 years or younger in PRO and patient satisfaction scores. The 2-year survivorship rate was 98.1% for the younger control group and 82.7% for the older study group. Therefore we believe that hip arthroscopy should be considered a valid treatment option when treating hip pain in patients aged 50 years or older with a Tönnis arthritic grade of 0 or 1. Older patients should be counseled on the possibility of later conversion to total hip arthroplasty. Future work may include development of a decision-making tool to assess for prognosis to better delineate the indications for hip arthroscopy in the older population. Level III, therapeutic case-control study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

New steps of robot-assisted radical prostatectomy using the extraperitoneal approach: a propensity-score matched comparison between extraperitoneal and transperitoneal approach in Japanese patients.

PubMed

Kurokawa, Satoshi; Umemoto, Yukihiro; Mizuno, Kentaro; Okada, Atsushi; Nakane, Akihiro; Nishio, Hidenori; Hamamoto, Shuzo; Ando, Ryosuke; Kawai, Noriyasu; Tozawa, Keiichi; Hayashi, Yutaro; Yasui, Takahiro

2017-11-21

Robot-assisted radical prostatectomy (RARP) is commonly performed using the transperitoneal (TP) approach with six trocars over an 8-cm distance in the steep Trendelenburg position. In this study, we investigated the feasibility and the benefit of using the extraperitoneal (EP) approach with six trocars over a 4-cm distance in a flat or 5° Trendelenburg position. We also introduced four new steps to the surgical procedure and compared the surgical results and complications between the EP and TP approach using propensity score matching. Between August 2012 and August 2016, 200 consecutive patients without any physical restrictions underwent RARP with the EP approach in a less than 5° Trendelenburg position, and 428 consecutive patients underwent RARP with the TP approach in a steep Trendelenburg position. Four new steps to RARP using the EP approach were developed: 1) arranging six trocars; 2) creating the EP space using laparoscopic forceps; 3) holding the separated prostate in the EP space outside the robotic view; and 4) preventing a postoperative inguinal hernia. Clinicopathological results and complications were compared between the EP and TP approaches using propensity score matching. Propensity scores were calculated for each patient using multivariate logistic regression based on the preoperative covariates. All 200 patients safely underwent RARP using the EP approach. The mean volume of estimated blood loss and duration of indwelling urethral catheter use were significantly lower with the EP approach than the TP approach (139.9 vs 184.9 mL, p = 0.03 and 5.6 vs 7.7 days, p < 0.01, respectively). No significant differences in the positive surgical margin were observed. None of the patients developed an inguinal hernia postoperatively after we introduced this technique. The EP approach to RARP was safely performed regardless of patient physique or contraindications to a steep Trendelenburg position. Our method, which involved using the EP approach to perform RARP, can decrease the amount of perioperative blood loss, the duration of indwelling urethral catheter use, and the incidence of postoperative inguinal hernia development.

Polytrauma Defined by the New Berlin Definition: A Validation Test Based on Propensity-Score Matching Approach.

PubMed

Rau, Cheng-Shyuan; Wu, Shao-Chun; Kuo, Pao-Jen; Chen, Yi-Chun; Chien, Peng-Chen; Hsieh, Hsiao-Yun; Hsieh, Ching-Hua

2017-09-11

Background: Polytrauma patients are expected to have a higher risk of mortality than that obtained by the summation of expected mortality owing to their individual injuries. This study was designed to investigate the outcome of patients with polytrauma, which was defined using the new Berlin definition, as cases with an Abbreviated Injury Scale (AIS) ≥ 3 for two or more different body regions and one or more additional variables from five physiologic parameters (hypotension [systolic blood pressure ≤ 90 mmHg], unconsciousness [Glasgow Coma Scale score ≤ 8], acidosis [base excess ≤ -6.0], coagulopathy [partial thromboplastin time ≥ 40 s or international normalized ratio ≥ 1.4], and age [≥70 years]). Methods: We retrieved detailed data on 369 polytrauma patients and 1260 non-polytrauma patients with an overall Injury Severity Score (ISS) ≥ 18 who were hospitalized between 1 January 2009 and 31 December 2015 for the treatment of all traumatic injuries, from the Trauma Registry System at a level I trauma center. Patients with burn injury or incomplete registered data were excluded. Categorical data were compared with two-sided Fisher exact or Pearson chi-square tests. The unpaired Student t -test and the Mann-Whitney U -test was used to analyze normally distributed continuous data and non-normally distributed data, respectively. Propensity-score matched cohort in a 1:1 ratio was allocated using the NCSS software with logistic regression to evaluate the effect of polytrauma on patient outcomes. Results: The polytrauma patients had a significantly higher ISS than non-polytrauma patients (median (interquartile range Q1-Q3), 29 (22-36) vs. 24 (20-25), respectively; p < 0.001). Polytrauma patients had a 1.9-fold higher odds of mortality than non-polytrauma patients (95% CI 1.38-2.49; p < 0.001). Compared to non-polytrauma patients, polytrauma patients had a substantially longer hospital length of stay (LOS). In addition, a higher proportion of polytrauma patients were admitted to the intensive care unit (ICU), spent longer LOS in the ICU, and had significantly higher total medical expenses. Among 201 selected propensity score-matched pairs of polytrauma and non-polytrauma patients who showed no significant difference in sex, age, co-morbidity, AIS ≥ 3, and Injury Severity Score (ISS), the polytrauma patients had a significantly higher mortality rate (OR 17.5, 95% CI 4.21-72.76; p < 0.001), and a higher proportion of patients admitted to the ICU (84.1% vs. 74.1%, respectively; p = 0.013) with longer stays in the ICU (10.3 days vs. 7.5 days, respectively; p = 0.003). The total medical expenses for polytrauma patients were 35.1% higher than those of non-polytrauma patients. However, there was no significant difference in the LOS between polytrauma and non-polytrauma patients (21.1 days vs. 19.8 days, respectively; p = 0.399). Conclusions: The findings of this propensity-score matching study suggest that the new Berlin definition of polytrauma is feasible and applicable for trauma patients.

Polytrauma Defined by the New Berlin Definition: A Validation Test Based on Propensity-Score Matching Approach

PubMed Central

Rau, Cheng-Shyuan; Wu, Shao-Chun; Kuo, Pao-Jen; Chen, Yi-Chun; Chien, Peng-Chen; Hsieh, Hsiao-Yun; Hsieh, Ching-Hua

2017-01-01

Background: Polytrauma patients are expected to have a higher risk of mortality than that obtained by the summation of expected mortality owing to their individual injuries. This study was designed to investigate the outcome of patients with polytrauma, which was defined using the new Berlin definition, as cases with an Abbreviated Injury Scale (AIS) ≥ 3 for two or more different body regions and one or more additional variables from five physiologic parameters (hypotension [systolic blood pressure ≤ 90 mmHg], unconsciousness [Glasgow Coma Scale score ≤ 8], acidosis [base excess ≤ −6.0], coagulopathy [partial thromboplastin time ≥ 40 s or international normalized ratio ≥ 1.4], and age [≥70 years]). Methods: We retrieved detailed data on 369 polytrauma patients and 1260 non-polytrauma patients with an overall Injury Severity Score (ISS) ≥ 18 who were hospitalized between 1 January 2009 and 31 December 2015 for the treatment of all traumatic injuries, from the Trauma Registry System at a level I trauma center. Patients with burn injury or incomplete registered data were excluded. Categorical data were compared with two-sided Fisher exact or Pearson chi-square tests. The unpaired Student t-test and the Mann–Whitney U-test was used to analyze normally distributed continuous data and non-normally distributed data, respectively. Propensity-score matched cohort in a 1:1 ratio was allocated using the NCSS software with logistic regression to evaluate the effect of polytrauma on patient outcomes. Results: The polytrauma patients had a significantly higher ISS than non-polytrauma patients (median (interquartile range Q1–Q3), 29 (22–36) vs. 24 (20–25), respectively; p < 0.001). Polytrauma patients had a 1.9-fold higher odds of mortality than non-polytrauma patients (95% CI 1.38–2.49; p < 0.001). Compared to non-polytrauma patients, polytrauma patients had a substantially longer hospital length of stay (LOS). In addition, a higher proportion of polytrauma patients were admitted to the intensive care unit (ICU), spent longer LOS in the ICU, and had significantly higher total medical expenses. Among 201 selected propensity score-matched pairs of polytrauma and non-polytrauma patients who showed no significant difference in sex, age, co-morbidity, AIS ≥ 3, and Injury Severity Score (ISS), the polytrauma patients had a significantly higher mortality rate (OR 17.5, 95% CI 4.21–72.76; p < 0.001), and a higher proportion of patients admitted to the ICU (84.1% vs. 74.1%, respectively; p = 0.013) with longer stays in the ICU (10.3 days vs. 7.5 days, respectively; p = 0.003). The total medical expenses for polytrauma patients were 35.1% higher than those of non-polytrauma patients. However, there was no significant difference in the LOS between polytrauma and non-polytrauma patients (21.1 days vs. 19.8 days, respectively; p = 0.399). Conclusions: The findings of this propensity-score matching study suggest that the new Berlin definition of polytrauma is feasible and applicable for trauma patients. PMID:28891977

Use of recombinant factor VIIa in US military casualties for a five-year period.

PubMed

Wade, Charles E; Eastridge, Brian J; Jones, John A; West, Susan A; Spinella, Philip C; Perkins, Jeremy G; Dubick, Michael A; Blackbourne, Lorne H; Holcomb, John B

2010-08-01

Two prospective randomized trauma trials have shown recombinant factor VIIa (rFVIIa) to be safe and to decrease transfusion requirements. rFVIIa is presently used in 22% of massively transfused civilian trauma patients. The US Military has used rFVIIa in combat trauma patients for five years, and two small studies of massively transfused patients described an association with improved outcomes. This study was undertaken to assess how deployed physicians are using rFVIIa and its impact on casualty outcomes. US combat casualties (n = 2,050) receiving any blood transfusion from 2003 to 2009 were reviewed to compare patients receiving rFVIIa (n = 506) with those who did not (n = 1,544). Propensity-score matching (primary analysis) and multivariable logistic regression were used to compare outcomes. Differences were determined at p < 0.05. Twenty-five percent of patients received rFVIIa. Significant differences were noted between groups in indices of injury severity (Injury Severity Score, Abbreviated Injury Scale score, and Glasgow Coma Scale score), admission physiology (systolic blood pressure, diastolic blood pressure, heart rate, temperature, base deficit, hemoglobin, and international normalization ratio), and use of blood products, indicating that patients treated with rFVIIa were more severely injured, in shock, and coagulopathic. For propensity-score matching, factors associated with death were used: Injury Severity Score, Glasgow Coma Scale score, heart rate, systolic blood pressure, diastolic blood pressure, Hgb, and total packed red blood cell. A total of 266 patients per group were matched; 52% of the rFVIIa group. After pairing, there were no significant differences in any of the demographics, including incidence of massive transfusion (53% vs. 51%). There was no difference in the rate of complications (21% vs. 21%) or mortality (14% vs. 20%) for patients not treated or receiving rFVIIa, respectively. In military casualties, rFVIIa is used in the most severely injured patients based on physician selection rather than on guideline criteria. Use of rFVIIa is not associated with an improvement in survival or an increase in complications. The undetected bias of physician selection of patients for treatment with rFVIIa, likely, has an impact on case matching to achieve equivalence similar to that of randomized control studies. This inability to match populations, thus, prevents definitive interpretation of this study and others studies of similar design. This problem emphasizes the need to develop entry criteria to identify patients who could potentially benefit from use of rFVIIa and the need to subsequently perform efficacy studies.

The Relationship Between Early-Stage Knee Osteoarthritis and Lower-Extremity Alignment, Joint Laxity, and Subjective Scores of Pain, Stiffness, and Function.

PubMed

Hicks-Little, Charlie A; Peindl, Richard D; Hubbard-Turner, Tricia J; Cordova, Mitchell L

2016-08-01

Knee osteoarthritis (OA) is a debilitating disease that affects an estimated 27 million Americans. Changes in lower-extremity alignment and joint laxity have been found to redistribute the medial and/or lateral loads at the joint. However, the effect that changes in anteroposterior knee-joint laxity have on lower-extremity alignment and function in individuals with knee OA remains unclear. To examine anteroposterior knee-joint laxity, lower-extremity alignment, and subjective pain, stiffness, and function scores in individuals with early-stage knee OA and matched controls and to determine if a relationship exists among these measures. Case control. Sports-medicine research laboratory. 18 participants with knee OA and 18 healthy matched controls. Participants completed the Western Ontario McMaster (WOMAC) osteoarthritis questionnaire and were tested for total anteroposterior knee-joint laxity (A-P) and knee-joint alignment (ALIGN). WOMAC scores, A-P (mm), and ALIGN (°). A significant multivariate main effect for group (Wilks' Λ = 0.30, F7,26 = 8.58, P < .0001) was found. Knee-OA participants differed in WOMAC scores (P < .0001) but did not differ from healthy controls on ALIGN (P = .49) or total A-P (P = .66). No significant relationships were identified among main outcome measures. These data demonstrate that participants with early-stage knee OA had worse pain, stiffness, and functional outcome scores than the matched controls; however, ALIGN and A-P were no different. There was no association identified among participants' subjective scores, ALIGN, or A-P measures in this study.

A Propensity Score Matching Analysis of the Effects of Special Education Services

PubMed Central

Morgan, Paul L.; Frisco, Michelle; Farkas, George; Hibel, Jacob

2013-01-01

We sought to quantify the effectiveness of special education services as naturally delivered in U.S. schools. Specifically, we examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem behaviors than closely matched peers not receiving such services. To do so, we used propensity score matching techniques to analyze data from the Early Childhood Longitudinal—Study Kindergarten Cohort, 1998–1999, a large scale, nationally representative sample of U.S. schoolchildren. Collectively, results indicate that receipt of special education services has either a negative or statistically non-significant impact on children’s learning or behavior. However, special education services do yield a small, positive effect on children’s learning-related behaviors. PMID:23606759

A Propensity Score Matching Analysis of the Effects of Special Education Services.

PubMed

Morgan, Paul L; Frisco, Michelle; Farkas, George; Hibel, Jacob

2010-02-01

We sought to quantify the effectiveness of special education services as naturally delivered in U.S. schools. Specifically, we examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem behaviors than closely matched peers not receiving such services. To do so, we used propensity score matching techniques to analyze data from the Early Childhood Longitudinal-Study Kindergarten Cohort, 1998-1999, a large scale, nationally representative sample of U.S. schoolchildren. Collectively, results indicate that receipt of special education services has either a negative or statistically non-significant impact on children's learning or behavior. However, special education services do yield a small, positive effect on children's learning-related behaviors.

Aortic Wall Extracellular Matrix Proteins Correlate with Syntax Score in Patients Undergoing Coronary Artery Bypass Surgery

PubMed Central

Chiong, Terri; Cheow, Esther S. H.; Woo, Chin C.; Lin, Xiao Y.; Khin, Lay W.; Lee, Chuen N.; Hartman, Mikael; Sze, Siu K.; Sorokin, Vitaly A.

2016-01-01

Aims: The SYNTAX score correlate with major cardiovascular events post-revascularization, although the histopathological basis is unclear. We aim to evaluate the association between syntax score and extracellular matrix histological characteristics of aortic punch tissue obtained during coronary artery bypass surgery (CABG). This analysis compares coronary artery bypass surgery patients with High and Low syntax score which were followed up for one year period. Methods and Results: Patients with High (score ≥ 33, (n=77)) and Low Syntax Scores (score ≤ 22, (n=71)) undergoing elective CABG were recruited prospectively. Baseline clinical characteristics and surgical risks were well matched. At 1 year, EMACCE (Sum of cardiovascular death, stroke, congestive cardiac failure, and limb, gut and myocardial ischemia) was significantly elevated in the High syntax group (P=0.022). Mass spectrometry (MS)-based quantitative iTRAQ proteomic results validated on independent cohort by immunohistochemistry (IHC) revealed that the High syntax group had significantly upraised Collagen I (P<0.0001) and Elastin (P<0.0001) content in ascending aortic wall. Conclusion: This study shows that aortic extracellular matrix (ECM) differ between High and Low syntax groups with up-regulation of Collagen I and Elastin level in High Syntax Score group. This identifies aortic punches collected during CABG as another biomarker source related with atherosclerosis severity and possible clinical outcome. PMID:27347220

Workload, Fatigue and Muscle Damage in an u20 Rugby Union Team Over an Intensified International Tournament.

PubMed

Lacome, Mathieu; Carling, Christopher; Hager, Jean-Philippe; Dine, Gerard; Piscione, Julien

2018-02-12

This study examined the effects of an intensified tournament on workload, perceptual and neuromuscular fatigue and muscle damage responses in an international under-20 rugby union team. Players were subdivided into two groups according to match-play exposure time: high (HEG, n=13) and low (LEG, n=11). Measures monitored over the 19-day period included training session (n=10) and match (n=5) workload determined via global positioning systems and session ratings of perceived exertion (sRPE). Wellbeing scores, countermovement jump height performance (CMJ) and blood creatine kinase [CK]b concentrations were collected at various time points. Analysis of workload cumulated across the tournament entirety for training and match-play combined showed that high-speed running distance was similar between groups while a very likely larger sRPE load was reported in HEG vs. LEG. In HEG high-speed activity fluctuated across the 5 successive matches albeit with no clear trend for a progressive decrease. No clear tendency for a progressive decrease in wellbeing scores prior to or following matches was observed in either group. In HEG trivial to possibly small reductions in post-match CMJ performance were observed while unclear to most likely moderate increases in pre-match [CK]b concentrations occurred until prior to match 4. The magnitude of match-to-match changes in external workload, perceptual and neuromuscular fatigue and muscle damage was generally unclear or small. These results suggest that irrespective of exposure time to match-play players generally maintained performance and readiness to play across the intensified tournament. These findings support the need for holistic systematic player monitoring programmes.

Does Timing of Internal Medicine Residency Interview Affect Likelihood of Matching?

PubMed

Heidemann, Danielle L; Thompson, Elizabeth; Drake, Sean M

2016-08-01

Applicants to our internal medicine (IM) residency program consistently have shared concerns about whether the interview date influences their ability to match via the National Residency Matching Program. We performed a retrospective study to assess whether interview timing was associated with successful matching at our IM program. We identified all of the applicants who interviewed for a first-year position with our IM residency program from 2010 to 2014. Each year's interview dates were totaled and divided equally into three categories: early, middle, or late. Baseline demographics, United States Medical Licensing Examination scores, and type of medical school (American or international) were compared among the interview date groups and between those who did and did not match at our program. Of 914 interviewees, 311 interviewed early (October/November), 299 interviewed in the middle (December), and 304 interviewed late (January). The proportion to match at our program was similar in each interview group (12.5%, 18.4%, 15.1%, respectively; P = 0.133). Logistic regression analysis showed that the middle interview group had increased odds to match compared with the early group (odds ratio 1.590; P = 0.044). The late-versus-early group showed no difference (P = 0.362). No significant differences were found with type of medical school or United States Medical Licensing Examination scores. Of all of the interviewees participating in the match, nearly all matched into a program somewhere, with no significant difference based on interview timing. When considering all of the interviewees, interview date showed no major influence on matching. Only the middle interview time period showed a slight increased chance of matching to our IM program, but the significance was marginal.

Contrasting State-of-the-Art in the Machine Scoring of Short-Form Constructed Responses

ERIC Educational Resources Information Center

Shermis, Mark D.

2015-01-01

This study compared short-form constructed responses evaluated by both human raters and machine scoring algorithms. The context was a public competition on which both public competitors and commercial vendors vied to develop machine scoring algorithms that would match or exceed the performance of operational human raters in a summative high-stakes…

Improving participant selection in disease management programmes: insights gained from propensity score stratification.

PubMed

Linden, Ariel; Adams, John L

2008-10-01

While the randomized controlled trial (RCT) remains the gold-standard study design for evaluating treatment effect, outcomes researchers turn to powerful quasi-experimental designs when only observational studies can be conducted. Within these designs, propensity score matching is one of the most popular to evaluate disease management (DM) programme effectiveness. Given that DM programmes generally have a much smaller number of participants than non-participants in the population, propensity score matching will typically result in all or nearly all participants finding successful matches, while most of the non-participants in the population remain unmatched and thereby excluded from the analysis. By excluding data from the unmatched population, the effect of non-treatment in the remaining population with the disease is not captured. In the present study, we examine changes in hospitalization rates stratified by propensity score quintiles across the entire population allowing us to gain insight as to how well the programme chose its participants, or if the programme could have been effective on those individuals not explicitly targeted for the intervention. These data indicate the presence of regression to the mean, and suggest that the DM programme may be overly limited to only the highest strata when there is evidence of a potential benefit for those in all the lower strata as well.

Effects of expertise on football betting.

PubMed

Khazaal, Yasser; Chatton, Anne; Billieux, Joël; Bizzini, Lucio; Monney, Grégoire; Fresard, Emmanuelle; Thorens, Gabriel; Bondolfi, Guido; El-Guebaly, Nady; Zullino, Daniele; Khan, Riaz

2012-05-11

Football (soccer) is one of the most popular sports in the world, including Europe. It is associated with important betting activities. A common belief, widely spread among those who participate in gambling activities, is that knowledge and expertise on football lead to better prediction skills for match outcomes. If unfounded, however, this belief should be considered as a form of "illusion of control." The aim of this study was to examine whether football experts are better than nonexperts at predicting football match scores. Two hundred and fifty-eight persons took part in the study: 21.3% as football experts, 54.3% as laypersons (non-initiated to football), and 24.4% as football amateurs. They predicted the scores of the first 10 matches of the 2008 UEFA European Football Championship. Logistic regressions were carried out to assess the link between the accuracy of the forecasted scores and the expertise of the participants (expert, amateur, layperson), controlling for age and gender. The variables assessed did not predict the accuracy of scoring prognosis (R2 ranged from 1% to 6%). Expertise, age, and gender did not appear to have an impact on the accuracy of the football match prognoses. Therefore, the belief that football expertise improves betting skills is no more than a cognitive distortion called the "illusion of control." Gamblers may benefit from psychological interventions that target the illusion of control related to their believed links between betting skills and football expertise. Public health policies may need to consider the phenomenon in order to prevent problem gambling related to football betting.

Chronic Azithromycin Use in Cystic Fibrosis and Risk of Treatment-Emergent Respiratory Pathogens.

PubMed

Cogen, Jonathan D; Onchiri, Frankline; Emerson, Julia; Gibson, Ronald L; Hoffman, Lucas R; Nichols, David P; Rosenfeld, Margaret

2018-02-23

Azithromycin has been shown to improve lung function and reduce the number of pulmonary exacerbations in cystic fibrosis patients. Concerns remain, however, regarding the potential emergence of treatment-related respiratory pathogens. To determine if chronic azithromycin use (defined as thrice weekly administration) is associated with increased rates of detection of eight specific respiratory pathogens. We performed a new-user, propensity-score matched retrospective cohort study utilizing data from the Cystic Fibrosis Foundation Patient Registry. Incident azithromycin users were propensity-score matched 1:1 with contemporaneous non-users. Kaplan-Meier curves and Cox proportional hazards regression were used to evaluate the association between chronic azithromycin use and incident respiratory pathogen detection. Analyses were performed separately for each pathogen, limited to patients among whom that pathogen had not been isolated in the two years prior to cohort entry. After propensity score matching, mean age of the cohorts was ~12 years. Chronic azithromycin users had a significantly lower risk of detection of new methicillin-resistant Staphylococcus aureus, non-tuberculous mycobacteria, and Burkholderia cepacia complex compared to non-users. The risk of acquiring the remaining five pathogens was not significantly different between users and non-users. Using an innovative new-user, propensity-score matched study design to minimize indication and selection biases, we found in a predominantly pediatric cohort that chronic azithromycin users had a lower risk of acquiring several cystic fibrosis-related respiratory pathogens. These results may ease concerns that chronic azithromycin exposure increases the risk of acquiring new respiratory pathogens among pediatric cystic fibrosis patients.

Confounding adjustment in comparative effectiveness research conducted within distributed research networks.

PubMed

Toh, Sengwee; Gagne, Joshua J; Rassen, Jeremy A; Fireman, Bruce H; Kulldorff, Martin; Brown, Jeffrey S

2013-08-01

A distributed research network (DRN) of electronic health care databases, in which data reside behind the firewall of each data partner, can support a wide range of comparative effectiveness research (CER) activities. An essential component of a fully functional DRN is the capability to perform robust statistical analyses to produce valid, actionable evidence without compromising patient privacy, data security, or proprietary interests. We describe the strengths and limitations of different confounding adjustment approaches that can be considered in observational CER studies conducted within DRNs, and the theoretical and practical issues to consider when selecting among them in various study settings. Several methods can be used to adjust for multiple confounders simultaneously, either as individual covariates or as confounder summary scores (eg, propensity scores and disease risk scores), including: (1) centralized analysis of patient-level data, (2) case-centered logistic regression of risk set data, (3) stratified or matched analysis of aggregated data, (4) distributed regression analysis, and (5) meta-analysis of site-specific effect estimates. These methods require different granularities of information be shared across sites and afford investigators different levels of analytic flexibility. DRNs are growing in use and sharing of highly detailed patient-level information is not always feasible in DRNs. Methods that incorporate confounder summary scores allow investigators to adjust for a large number of confounding factors without the need to transfer potentially identifiable information in DRNs. They have the potential to let investigators perform many analyses traditionally conducted through a centralized dataset with detailed patient-level information.

Correlation between cognitive impairment during the acute phase of first cerebral infarction and development of long-term pseudobulbar affect

PubMed Central

Wang, Yuan; Wang, Yuliang; Ma, Wenbin; Lu, Shujun; Chen, Jinbo; Cao, Lili

2018-01-01

Purpose The relationship between cognitive impairment during the acute phase of first cerebral infarction and the development of long-term pseudobulbar affect (PBA) has not been elucidated. Therefore, in this study, we aimed to determine if cognitive impairment during the acute phase of cerebral infarction will increase the risk of long-term post-infarction PBA. Patients and methods This was a nested case–control study using a prospective approach. A consecutive multicenter matched 1:1 case–control study of cognitive impairment cases following acute cerebral infarction (N=26) with 26 sex-, education years-, and age-matched controls. Univariate and multivariate conditional logistic regression analyses were performed to study the clinical features and changes in cognitive domain as well as the risk factors for PBA. Results Long-term PBA was independently predicted by low Montreal cognitive assessment (MoCA) scores at baseline. Multivariable regression models showed that post-infarction low MoCA scores remained independent predictors of long-term PBA (odds ratio [OR]=0.72; 95% confidence interval [CI]=0.54–0.95; P=0.018). Among all cognitive disorders, digit span test (DST) scores (OR=0.39; 95% CI=0.16–0.91, P=0.030), StroopC time (OR=1.15; 95% CI=1.01–1.31; P=0.037), and clock-drawing task (CDT) scores (OR=0.62; 95% CI=0.42–0.90; P=0.013) were found to be the independent risk factors for PBA. Conclusion Cognitive impairment during the acute phase of cerebral infarction increased the risk of cerebral infarction-induced long-term PBA. Development of PBA was closely associated with executive function, attention, and visuospatial disorder. PMID:29636612

Atrial natriuretic peptide therapy and in-hospital mortality in acute myocardial infarction patients undergoing percutaneous coronary intervention.

PubMed

Isogai, Toshiaki; Matsui, Hiroki; Tanaka, Hiroyuki; Fushimi, Kiyohide; Yasunaga, Hideo

2016-11-01

Atrial natriuretic peptide (ANP) therapy has been reported to have beneficial effects in patients with acute myocardial infarction (AMI); however, its impact on in-hospital mortality remains unclear. This study aimed to investigate the effects of ANP therapy on in-hospital mortality in AMI patients undergoing percutaneous coronary intervention (PCI). This was a retrospective cohort study using the Diagnosis Procedure Combination inpatient database in Japan. We identified AMI patients who underwent PCI with stent implantation on the day of admission, between 2010 and 2014. We compared 30-day in-hospital mortality between patients who started ANP therapy on the day of admission (ANP group) and those who received no ANP therapy during hospitalization (control group), using propensity score and instrumental variable methods. Of 60,592 eligible patients (8189 ANP group, 52,403 control group) from 850 hospitals, 1:1 propensity score matching created 8027 pairs. There was no significant difference in 30-day in-hospital mortality between the ANP and control groups (3.4% vs. 3.8%, respectively; p=0.162; risk difference, -0.42%; 95% confidence interval [CI], -1.00% to 0.15%) in the propensity score-matched cohort. Logistic regression analysis with adjustment for propensity score deciles found no significant association between ANP therapy and 30-day in-hospital mortality (odds ratio, 0.99; 95% CI, 0.82 to 1.19). Instrumental variable analysis also showed no significant association between ANP therapy and 30-day in-hospital mortality (risk difference, -0.59%; 95% CI, -1.24% to 0.05%). This study found no significant association between ANP therapy and in-hospital mortality in AMI patients undergoing PCI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A comparison of two prospective risk analysis methods: Traditional FMEA and a modified healthcare FMEA.

PubMed

Rah, Jeong-Eun; Manger, Ryan P; Yock, Adam D; Kim, Gwe-Ya

2016-12-01

To examine the abilities of a traditional failure mode and effects analysis (FMEA) and modified healthcare FMEA (m-HFMEA) scoring methods by comparing the degree of congruence in identifying high risk failures. The authors applied two prospective methods of the quality management to surface image guided, linac-based radiosurgery (SIG-RS). For the traditional FMEA, decisions on how to improve an operation were based on the risk priority number (RPN). The RPN is a product of three indices: occurrence, severity, and detectability. The m-HFMEA approach utilized two indices, severity and frequency. A risk inventory matrix was divided into four categories: very low, low, high, and very high. For high risk events, an additional evaluation was performed. Based upon the criticality of the process, it was decided if additional safety measures were needed and what they comprise. The two methods were independently compared to determine if the results and rated risks matched. The authors' results showed an agreement of 85% between FMEA and m-HFMEA approaches for top 20 risks of SIG-RS-specific failure modes. The main differences between the two approaches were the distribution of the values and the observation that failure modes (52, 54, 154) with high m-HFMEA scores do not necessarily have high FMEA-RPN scores. In the m-HFMEA analysis, when the risk score is determined, the basis of the established HFMEA Decision Tree™ or the failure mode should be more thoroughly investigated. m-HFMEA is inductive because it requires the identification of the consequences from causes, and semi-quantitative since it allows the prioritization of high risks and mitigation measures. It is therefore a useful tool for the prospective risk analysis method to radiotherapy.

Autonomic symptoms are common and are associated with overall symptom burden and disease activity in primary Sjögren's syndrome

PubMed Central

Newton, Julia L; Frith, James; Powell, Danielle; Hackett, Kate; Wilton, Katharine; Bowman, Simon; Price, Elizabeth; Pease, Colin; Andrews, Jacqueline; Emery, Paul; Hunter, John; Gupta, Monica; Vadivelu, Saravanan; Giles, Ian; Isenberg, David; Lanyon, Peter; Jones, Adrian; Regan, Marian; Cooper, Annie; Moots, Robert; Sutcliffe, Nurhan; Bombardieri, Michele; Pitzalis, Costantino; McLaren, John; Young-Min, Steven; Dasgupta, Bhaskar; Griffiths, Bridget; Lendrem, Dennis; Mitchell, Sheryl; Ng, Wan-Fai

2012-01-01

Objectives To determine the prevalence of autonomic dysfunction (dysautonomia) among patients with primary Sjögren's syndrome (PSS) and the relationships between dysautonomia and other clinical features of PSS. Methods Multicentre, prospective, cross-sectional study of a UK cohort of 317 patients with clinically well-characterised PSS. Symptoms of autonomic dysfunction were assessed using a validated instrument, the Composite Autonomic Symptom Scale (COMPASS). The data were compared with an age- and sex-matched cohort of 317 community controls. The relationships between symptoms of dysautonomia and various clinical features of PSS were analysed using regression analysis. Results COMPASS scores were significantly higher in patients with PSS than in age- and sex-matched community controls (median (IQR) 35.5 (20.9–46.0) vs 14.8 (4.4–30.2), p<0.0001). Nearly 55% of patients (vs 20% of community controls, p<0.0001) had a COMPASS score >32.5, a cut-off value indicative of autonomic dysfunction. Furthermore, the COMPASS total score correlated independently with EULAR Sjögren's Syndrome Patient Reported Index (a composite measure of the overall burden of symptoms experienced by patients with PSS) (β=0.38, p<0.001) and disease activity measured using the EULAR Sjögren's Syndrome Disease Activity Index (β=0.13, p<0.009). Conclusions Autonomic symptoms are common among patients with PSS and may contribute to the overall burden of symptoms and link with systemic disease activity. PMID:22562982

Comparison of two equivalent model for end-stage liver disease scores for hepatocellular carcinoma patients using data from the United Network for Organ Sharing liver transplant waiting list registry.

PubMed

Alver, Sarah K; Lorenz, Douglas J; Washburn, Kenneth; Marvin, Michael R; Brock, Guy N

2017-11-01

Patients with hepatocellular carcinoma (HCC) have been advantaged on the liver transplant waiting list within the United States, and a 6-month delay and exception point cap have recently been implemented to address this disparity. An alternative approach to prioritization is an HCC-specific scoring model such as the MELD Equivalent (MELD EQ ) and the mixed new deMELD. Using data on adult patients added to the UNOS waitlist between 30 September 2009 and 30 June 2014, we compared projected dropout and transplant probabilities for patients with HCC under these two models. Both scores matched actual non-HCC dropout in groups with scores <22 and improved equity with non-HCC transplant probabilities overall. However, neither score matched non-HCC dropout accurately for scores of 25-40 and projected dropout increased beyond non-HCC probabilities for scores <16. The main differences between the two scores were as follows: (i) the MELD EQ assigns 6.85 more points after 6 months on the waitlist and (ii) the deMELD gives greater weight to tumor size and laboratory MELD. Post-transplant survival was lower for patients with scores in the 22-30 range compared with those with scores <16 (P = 0.007, MELD EQ ; P = 0.015, deMELD). While both scores result in better equity of waitlist outcomes compared with scheduled progression, continued development and calibration is recommended. © 2017 Steunstichting ESOT.

Intervertebral anticollision constraints improve out-of-plane translation accuracy of a single-plane fluoroscopy-to-CT registration method for measuring spinal motion

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

Lin, Cheng-Chung; Tsai, Tsung-Yuan; Hsu, Shih-Jung

2013-03-15

Purpose: The study aimed to propose a new single-plane fluoroscopy-to-CT registration method integrated with intervertebral anticollision constraints for measuring three-dimensional (3D) intervertebral kinematics of the spine; and to evaluate the performance of the method without anticollision and with three variations of the anticollision constraints via an in vitro experiment. Methods: The proposed fluoroscopy-to-CT registration approach, called the weighted edge-matching with anticollision (WEMAC) method, was based on the integration of geometrical anticollision constraints for adjacent vertebrae and the weighted edge-matching score (WEMS) method that matched the digitally reconstructed radiographs of the CT models of the vertebrae and the measured single-plane fluoroscopymore » images. Three variations of the anticollision constraints, namely, T-DOF, R-DOF, and A-DOF methods, were proposed. An in vitro experiment using four porcine cervical spines in different postures was performed to evaluate the performance of the WEMS and the WEMAC methods. Results: The WEMS method gave high precision and small bias in all components for both vertebral pose and intervertebral pose measurements, except for relatively large errors for the out-of-plane translation component. The WEMAC method successfully reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five degrees of freedom (DOF) more or less unaltered. The means (standard deviations) of the out-of-plane translational errors were less than -0.5 (0.6) and -0.3 (0.8) mm for the T-DOF method and the R-DOF method, respectively. Conclusions: The proposed single-plane fluoroscopy-to-CT registration method reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five DOF more or less unaltered. With the submillimeter and subdegree accuracy, the WEMAC method was considered accurate for measuring 3D intervertebral kinematics during various functional activities for research and clinical applications.« less

Analysis of Observational Studies in the Presence of Treatment Selection Bias: Effects of Invasive Cardiac Management on AMI Survival Using Propensity Score and Instrumental Variable Methods

PubMed Central

Stukel, Thérèse A.; Fisher, Elliott S; Wennberg, David E.; Alter, David A.; Gottlieb, Daniel J.; Vermeulen, Marian J.

2007-01-01

Context Comparisons of outcomes between patients treated and untreated in observational studies may be biased due to differences in patient prognosis between groups, often because of unobserved treatment selection biases. Objective To compare 4 analytic methods for removing the effects of selection bias in observational studies: multivariable model risk adjustment, propensity score risk adjustment, propensity-based matching, and instrumental variable analysis. Design, Setting, and Patients A national cohort of 122 124 patients who were elderly (aged 65–84 years), receiving Medicare, and hospitalized with acute myocardial infarction (AMI) in 1994–1995, and who were eligible for cardiac catheterization. Baseline chart reviews were taken from the Cooperative Cardiovascular Project and linked to Medicare health administrative data to provide a rich set of prognostic variables. Patients were followed up for 7 years through December 31, 2001, to assess the association between long-term survival and cardiac catheterization within 30 days of hospital admission. Main Outcome Measure Risk-adjusted relative mortality rate using each of the analytic methods. Results Patients who received cardiac catheterization (n=73 238) were younger and had lower AMI severity than those who did not. After adjustment for prognostic factors by using standard statistical risk-adjustment methods, cardiac catheterization was associated with a 50% relative decrease in mortality (for multivariable model risk adjustment: adjusted relative risk [RR], 0.51; 95% confidence interval [CI], 0.50–0.52; for propensity score risk adjustment: adjusted RR, 0.54; 95% CI, 0.53–0.55; and for propensity-based matching: adjusted RR, 0.54; 95% CI, 0.52–0.56). Using regional catheterization rate as an instrument, instrumental variable analysis showed a 16% relative decrease in mortality (adjusted RR, 0.84; 95% CI, 0.79–0.90). The survival benefits of routine invasive care from randomized clinical trials are between 8% and 21 %. Conclusions Estimates of the observational association of cardiac catheterization with long-term AMI mortality are highly sensitive to analytic method. All standard risk-adjustment methods have the same limitations regarding removal of unmeasured treatment selection biases. Compared with standard modeling, instrumental variable analysis may produce less biased estimates of treatment effects, but is more suited to answering policy questions than specific clinical questions. PMID:17227979

How well will you FIT? Use of a modified MMI to assess applicants' compatibility with an emergency medicine residency program.

PubMed

Min, Alice A; Leetch, Aaron; Nuño, Tomas; Fiorello, Albert B

2016-01-01

Purpose Emergency medicine residency programs have evaluated the use of Multiple Mini Interviews (MMIs) for applicants. The authors developed an MMI-style method called the Fast Interview Track (FIT) to predict an applicant's 'fit' within an individual residency program. Methods Applicants meet with up to five residents and are asked one question by each. Residents score the applicant using a Likert scale from 1 to 5 on two questions: 'How well does the applicant think on his/her feet?' and 'How well do you think the applicant will fit in here?'. To assess how well these questions predicted a resident's 'fit', current residents scored fellow residents on these same questions. These scores were compared with the residents' interview FIT scores. A postmatch survey of applicants who did not match at this program solicited applicants' attitudes toward the FIT sessions. Results Among the junior class, the correlation between interview and current scores was significant for question 1 (rho=0.5192 [p=0.03]) and question 2 (rho=0.5753 [p=0.01]). Among seniors, Spearman's rho was statistically significant for question 2, though not statistically significant for question 1. The chi-square measure of high scores (4-5) versus low scores (1-3) found a statistically significant association between interview and current scores for interns and juniors. Of the 29 responses to the postmatch survey, 16 (55%) felt FIT sessions provided a good sense of the program's personality and only 6 (21%) disagreed. Nine (31%) felt FIT sessions positively impacted our program's ranking and 11 (38%) were 'Neutral'. Only two (7%) reported that FIT sessions negatively impacted their ranking of our program. Conclusions FIT provided program leadership with a sense of an applicant's 'fit' within this program. Interview day scores correlated with scores received during residency. Most applicants report a positive experience with FIT sessions. FIT provides a useful tool to recruit applicants who fit with the residency program.

Tumor Microenvironment of Metastasis and Risk of Distant Metastasis of Breast Cancer

PubMed Central

Xue, Xiaonan; Lin, Hung-Mo; D’Alfonso, Timothy M.; Ginter, Paula S.; Oktay, Maja H.; Robinson, Brian D.; Ginsberg, Mindy; Gertler, Frank B.; Glass, Andrew G.; Sparano, Joseph A.; Condeelis, John S.; Jones, Joan G.

2014-01-01

Background Tumor microenvironment of metastasis (TMEM), consisting of direct contact between a macrophage, an endothelial cell, and a tumor cell, has been associated with metastasis in both rodent mammary tumors and human breast cancer. We prospectively examined the association between TMEM score and risk of distant metastasis and compared risk associated with TMEM score with that associated with IHC4. Methods We conducted a case–control study nested within a cohort of 3760 patients with invasive ductal breast carcinoma diagnosed between 1980 and 2000 and followed through 2010. Case patients were women who developed a subsequent distant metastasis; control subjects were matched (1:1) on age at and calendar year of primary diagnosis. TMEM was assessed by triple immunostain and IHC4 by standard methods; slides were read by pathologists blinded to outcome. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, adjusted for clinical variables. A Receiver Operating Characteristic analysis was performed, and the area under the curve was estimated. All statistical tests were two-sided. Results TMEM score was associated with increased risk of distant metastasis in estrogen receptor (ER)+/human epidermal growth factor receptor (HER2)− tumors (multivariable OR high vs low tertile = 2.70; 95% CI = 1.39 to 5.26; P trend = .004), whereas IHC4 score had a borderline positive association (OR10 unit increase = 1.06; 95% CI = 1.00 to 1.13); the association for TMEM score persisted after adjustment for IHC4 score. The area under the curve for TMEM, adjusted for clinical variables, was 0.78. Neither TMEM score nor IHC4 score was independently associated with metastatic risk overall or in the triple negative or HER2+ subgroups. Conclusions TMEM score predicted risk of distant metastasis in ER+/HER2− breast cancer independently of IHC4 score and classical clinicopathologic features. PMID:24895374

The Value of the Studied Item in the Matching Criterion in Differential Item Functioning (DIF) Analysis. Research Report. ETS RR-10-13

ERIC Educational Resources Information Center

Tan, Xuan; Xiang, Bihua; Dorans, Neil J.; Qu, Yanxuan

2010-01-01

The nature of the matching criterion (usually the total score) in the study of differential item functioning (DIF) has been shown to impact the accuracy of different DIF detection procedures. One of the topics related to the nature of the matching criterion is whether the studied item should be included. Although many studies exist that suggest…

Score level fusion scheme based on adaptive local Gabor features for face-iris-fingerprint multimodal biometric

NASA Astrophysics Data System (ADS)

He, Fei; Liu, Yuanning; Zhu, Xiaodong; Huang, Chun; Han, Ye; Chen, Ying

2014-05-01

A multimodal biometric system has been considered a promising technique to overcome the defects of unimodal biometric systems. We have introduced a fusion scheme to gain a better understanding and fusion method for a face-iris-fingerprint multimodal biometric system. In our case, we use particle swarm optimization to train a set of adaptive Gabor filters in order to achieve the proper Gabor basic functions for each modality. For a closer analysis of texture information, two different local Gabor features for each modality are produced by the corresponding Gabor coefficients. Next, all matching scores of the two Gabor features for each modality are projected to a single-scalar score via a trained, supported, vector regression model for a final decision. A large-scale dataset is formed to validate the proposed scheme using the Facial Recognition Technology database-fafb and CASIA-V3-Interval together with FVC2004-DB2a datasets. The experimental results demonstrate that as well as achieving further powerful local Gabor features of multimodalities and obtaining better recognition performance by their fusion strategy, our architecture also outperforms some state-of-the-art individual methods and other fusion approaches for face-iris-fingerprint multimodal biometric systems.

The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters

PubMed Central

Galetta, K.M.; Barrett, J.; Allen, M.; Madda, F.; Delicata, D.; Tennant, A.T.; Branas, C.C.; Maguire, M.G.; Messner, L.V.; Devick, S.; Galetta, S.L.

2011-01-01

Objective: Sports-related concussion has received increasing attention as a cause of short- and long-term neurologic symptoms among athletes. The King-Devick (K-D) test is based on measurement of the speed of rapid number naming (reading aloud single-digit numbers from 3 test cards), and captures impairment of eye movements, attention, language, and other correlates of suboptimal brain function. We investigated the K-D test as a potential rapid sideline screening for concussion in a cohort of boxers and mixed martial arts fighters. Methods: The K-D test was administered prefight and postfight. The Military Acute Concussion Evaluation (MACE) was administered as a more comprehensive but longer test for concussion. Differences in postfight K-D scores and changes in scores from prefight to postfight were compared for athletes with head trauma during the fight vs those without. Results: Postfight K-D scores (n = 39 participants) were significantly higher (worse) for those with head trauma during the match (59.1 ± 7.4 vs 41.0 ± 6.7 seconds, p < 0.0001, Wilcoxon rank sum test). Those with loss of consciousness showed the greatest worsening from prefight to postfight. Worse postfight K-D scores (rs = −0.79, p = 0.0001) and greater worsening of scores (rs = 0.90, p < 0.0001) correlated well with postfight MACE scores. Worsening of K-D scores by ≥5 seconds was a distinguishing characteristic noted only among participants with head trauma. High levels of test-retest reliability were observed (intraclass correlation coefficient 0.97 [95% confidence interval 0.90–1.0]). Conclusions: The K-D test is an accurate and reliable method for identifying athletes with head trauma, and is a strong candidate rapid sideline screening test for concussion. PMID:21288984

Developing an instrument to measure heart failure disease management program intensity and complexity.

PubMed

Riegel, Barbara; Lee, Christopher S; Sochalski, Julie

2010-05-01

Comparing disease management programs and their effects is difficult because of wide variability in program intensity and complexity. The purpose of this effort was to develop an instrument that can be used to describe the intensity and complexity of heart failure (HF) disease management programs. Specific composition criteria were taken from the American Heart Association (AHA) taxonomy of disease management and hierarchically scored to allow users to describe the intensity and complexity of the domains and subdomains of HF disease management programs. The HF Disease Management Scoring Instrument (HF-DMSI) incorporates 6 of the 8 domains from the taxonomy: recipient, intervention content, delivery personnel, method of communication, intensity/complexity, and environment. The 3 intervention content subdomains (education/counseling, medication management, and peer support) are described separately. In this first test of the HF-DMSI, overall intensity (measured as duration) and complexity were rated using an ordinal scoring system. Possible scores reflect a clinical rationale and differ by category, with zero given only if the element could potentially be missing (eg, surveillance by remote monitoring). Content validity was evident as the instrument matches the existing AHA taxonomy. After revision and refinement, 2 authors obtained an inter-rater reliability intraclass correlation coefficient score of 0.918 (confidence interval, 0.880 to 0.944, P<0.001) in their rating of 12 studies. The areas with most variability among programs were delivery personnel and method of communication. The HF-DMSI is useful for describing the intensity and complexity of HF disease management programs.

The Safety of Ovarian Preservation in Stage I Endometrial Endometrioid Adenocarcinoma Based on Propensity Score Matching.

PubMed

Hou, Ting; Sun, Yidi; Li, Junyi; Liu, Chenglin; Wang, Zhen; Li, Yixue; Lu, Yuan

2017-01-01

Most patients with early stage endometrial endometrioid adenocarcinoma (EEAC) are treated with hysterectomy and bilateral oophorectomy. But this surgical menopause leads to long-term sequelae for premenopausal women, especially for young women of childbearing age. This population-based study was to evaluate the safety of ovarian preservation in young women with stage I EEAC. Patients of age 50 or younger with stage I EEAC were explored from the Surveillance, Epidemiology and End Results program database during 2004 to 2013. Propensity score matching was used to randomize the data set and reduce the selection biases of doctors. Univariate analysis and multivariate cox proportional hazards model were utilized to estimate the safety of ovarian preservation. A total of 7183 patients were identified, and ovarian preservation was performed in 863 (12 %) patients. Compared with women treated with oophorectomy, patients with ovarian preservation significantly tend to be younger at diagnosis (P-value < 0.001) and more likely diagnosed as stage IA EEAC, to have better differentiated tumor tissues and smaller tumors, as well as less likely to undergo radiation and lymphadenectomy. 863 patients treated with oophorectomy were selected by propensity score matching. After propensity score matching, the differences of all characteristics between ovarian preservation and oophorectomy were not significant and potential confounders in the two groups decreased. In univariate analysis of matched population, ovarian preservation had no effect on overall (P-value=0.928) and cancer-specific (P-value=0.390) mortality. In propensityadjusted multivariate analysis, ovarian preservation was not significantly associated with overall (HR=0.69, 95%CI=0.41-1.68, P-value=0.611) and cancer-specific (HR=1.65, 95%CI=0.54-5.06, Pvalue= 0.379) survival. Ovarian preservation is safe for young women with stage I EEAC, which is not significantly associated with overall and cancer-specific mortality. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

An Algorithm for Creating Virtual Controls Using Integrated and Harmonized Longitudinal Data.

PubMed

Hansen, William B; Chen, Shyh-Huei; Saldana, Santiago; Ip, Edward H

2018-06-01

We introduce a strategy for creating virtual control groups-cases generated through computer algorithms that, when aggregated, may serve as experimental comparators where live controls are difficult to recruit, such as when programs are widely disseminated and randomization is not feasible. We integrated and harmonized data from eight archived longitudinal adolescent-focused data sets spanning the decades from 1980 to 2010. Collectively, these studies examined numerous psychosocial variables and assessed past 30-day alcohol, cigarette, and marijuana use. Additional treatment and control group data from two archived randomized control trials were used to test the virtual control algorithm. Both randomized controlled trials (RCTs) assessed intentions, normative beliefs, and values as well as past 30-day alcohol, cigarette, and marijuana use. We developed an algorithm that used percentile scores from the integrated data set to create age- and gender-specific latent psychosocial scores. The algorithm matched treatment case observed psychosocial scores at pretest to create a virtual control case that figuratively "matured" based on age-related changes, holding the virtual case's percentile constant. Virtual controls matched treatment case occurrence, eliminating differential attrition as a threat to validity. Virtual case substance use was estimated from the virtual case's latent psychosocial score using logistic regression coefficients derived from analyzing the treatment group. Averaging across virtual cases created group estimates of prevalence. Two criteria were established to evaluate the adequacy of virtual control cases: (1) virtual control group pretest drug prevalence rates should match those of the treatment group and (2) virtual control group patterns of drug prevalence over time should match live controls. The algorithm successfully matched pretest prevalence for both RCTs. Increases in prevalence were observed, although there were discrepancies between live and virtual control outcomes. This study provides an initial framework for creating virtual controls using a step-by-step procedure that can now be revised and validated using other prevention trial data.

Cancer Recurrence After Esophagectomy: Impact of Postoperative Infection in Propensity-Matched Cohorts.

PubMed

Tam, Vernissia; Luketich, James D; Winger, Daniel G; Sarkaria, Inderpal S; Levy, Ryan M; Christie, Neil A; Awais, Omar; Shende, Manisha R; Nason, Katie S

2016-11-01

Postoperative infection increases cancer recurrence and worsens survival in colorectal cancer, but the relationship for esophagogastric adenocarcinoma after esophagectomy is not well defined. We aimed to determine whether recurrence and survival after minimally invasive esophagectomy for esophagogastric adenocarcinoma were influenced by postoperative infection using propensity-matched analysis. We abstracted data for 810 patients (1997-2010) and defined exposure as at least 1 in-hospital or 30-day infectious complication (n = 206 [25%]). Using 29 pretreatment/intraoperative variables, patients were propensity-score matched (caliper = 0.05). Time to cancer recurrence and survival (Kaplan-Meier curves and the Breslow test), and associated factors (Cox regression with shared frailty) were assessed. After propensity matching (n = 167 pairs), median bias across propensity-score variables was reduced from 12.9% (p < 0.001) to 4.4% (p = 1.000). Postoperative infection was not associated with rate (n = 60 versus 63; McNemar p = 0.736) or time to recurrence in those in whom disease recurred (median, 10.7 versus 11.1 months; Wilcoxon signed-rank p = 0.455) but was associated with shorter overall survival (n = 124 versus 102 deaths; median, 26 versus 41 months; Breslow p = 0.002). After adjusting for age, body mass index, neoadjuvant therapy, sex, comorbidity score, positive resection margins, pathologic stage, R0 resection, and recurrence, postoperative infection was associated with a 44% greater hazard for death (hazard ratio, 1.44; 95% confidence interval, 1.10-1.89). In patients with esophagogastric adenocarcinoma, infections after esophagectomy were not associated with an increased rate or earlier time to recurrence when baseline characteristics associated with infection risk were balanced using propensity-score matching. Despite this, overall survival was shorter in patients with infectious complications. After adjusting for other important survival predictors, infections after esophagectomy continued to be independently associated with worse survival. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

MeSHLabeler: improving the accuracy of large-scale MeSH indexing by integrating diverse evidence

PubMed Central

Liu, Ke; Peng, Shengwen; Wu, Junqiu; Zhai, Chengxiang; Mamitsuka, Hiroshi; Zhu, Shanfeng

2015-01-01

Motivation: Medical Subject Headings (MeSHs) are used by National Library of Medicine (NLM) to index almost all citations in MEDLINE, which greatly facilitates the applications of biomedical information retrieval and text mining. To reduce the time and financial cost of manual annotation, NLM has developed a software package, Medical Text Indexer (MTI), for assisting MeSH annotation, which uses k-nearest neighbors (KNN), pattern matching and indexing rules. Other types of information, such as prediction by MeSH classifiers (trained separately), can also be used for automatic MeSH annotation. However, existing methods cannot effectively integrate multiple evidence for MeSH annotation. Methods: We propose a novel framework, MeSHLabeler, to integrate multiple evidence for accurate MeSH annotation by using ‘learning to rank’. Evidence includes numerous predictions from MeSH classifiers, KNN, pattern matching, MTI and the correlation between different MeSH terms, etc. Each MeSH classifier is trained independently, and thus prediction scores from different classifiers are incomparable. To address this issue, we have developed an effective score normalization procedure to improve the prediction accuracy. Results: MeSHLabeler won the first place in Task 2A of 2014 BioASQ challenge, achieving the Micro F-measure of 0.6248 for 9,040 citations provided by the BioASQ challenge. Note that this accuracy is around 9.15% higher than 0.5724, obtained by MTI. Availability and implementation: The software is available upon request. Contact: zhusf@fudan.edu.cn PMID:26072501

Flexible band versus rigid ring annuloplasty for functional tricuspid regurgitation: two different patterns of right heart reverse remodelling

PubMed Central

Gatti, Giuseppe; Dell'Angela, Luca; Morosin, Marco; Maschietto, Luca; Pinamonti, Bruno; Benussi, Bernardo; Forti, Gabriella; Nicolosi, Gian Luigi; Sinagra, Gianfranco; Pappalardo, Aniello

2016-01-01

OBJECTIVES Annuloplasty bands and rings are widely used to treat functional tricuspid regurgitation (TR). However, the question as to which is the ideal annuloplasty device remains open. Early and late outcomes of tricuspid valve annuloplasty with flexible band (B-TVA) or rigid ring (R-TVA) are compared in the present study. METHODS Between 1999 and 2014, 462 consecutive patients (mean age, 69.2 ± 9.5 years) with grade ≥1+ functional TR (graded from 0 to 3+) underwent either B-TVA (n = 345; mean EuroSCORE II 9.2 ± 10.8%) or R-TVA (n = 117; mean EuroSCORE II 12 ± 13.4%) in addition to other cardiac procedures at the authors' institution. RESULTS One-to-one propensity score-matched analysis resulted in 98 pairs with similar baseline characteristics and operative risk. Hospital mortality was 7.5% after B-TVA and 12% after R-TVA (P = 0.14). R-TVA was associated with higher rates of low cardiac output (10.1 vs 17.9%, P = 0.025) and transient complete atrioventricular block (10.3 vs 17.2%, P = 0.046). Among the matched pairs, there were no significant differences in hospital mortality (5.1 vs 9.2%, P = 0.27) and perioperative complications. Both in overall series and matched pairs, between B-TVA and R-TVA patients, there were no significant differences in freedom from all-cause death (P = 0.29 and 0.91), cardiac and cerebrovascular deaths (P = 0.63 and 0.87) and grade ≥2+ TR (P = 0.68 and 0.77). Right atrial and tricuspid valve reverse remodelling combined with right ventricular reverse remodelling occurred after R-TVA but not after B-TVA. CONCLUSIONS B-TVA and R-TVA are equally effective in the treatment of functional TR. However, R-TVA causes over time a more complete right heart reverse remodelling. PMID:26993479

Confronting ‘confounding by health system use’ in Medicare Part D: Comparative effectiveness of propensity score approaches to confounding adjustment

PubMed Central

Polinski, Jennifer M.; Schneeweiss, Sebastian; Glynn, Robert J.; Lii, Joyce; Rassen, Jeremy

2012-01-01

Purpose Under Medicare Part D, patient characteristics influence plan choice, which in turn influences Part D coverage gap entry. We compared pre-defined propensity score (PS) and high-dimensional propensity score (hdPS) approaches to address such ‘confounding by health system use’ in assessing whether coverage gap entry is associated with cardiovascular events or death. Methods We followed 243,079 Medicare patients aged 65+ with linked prescription, medical, and plan-specific data in 2005–2007. Patients reached the coverage gap and were followed until an event or year’s end. Exposed patients were responsible for drug costs in the gap; unexposed patients (patients with non-Part D drug insurance and Part D patients receiving a low-income subsidy (LIS)) received financial assistance. Exposed patients were 1:1 PS- or hdPS-matched to unexposed patients. The PS model included 52 predefined covariates; the hdPS model added 400 empirically identified covariates. Hazard ratios for death and any of five cardiovascular outcomes were compared. In sensitivity analyses, we explored residual confounding using only LIS patients in the unexposed group. Results In unadjusted analyses, exposed patients had no greater hazard of death (HR=1.00; 95% CI, 0.84–1.20) or other outcomes. PS- (HR=1.29;0.99–1.66) and hdPS- (HR=1.11;0.86–1.42) matched analyses showed elevated but non-significant hazards of death. In sensitivity analyses, the PS analysis showed a protective effect (HR=0.78;0.61–0.98), while the hdPS analysis (HR=1.06;0.82–1.37) confirmed the main hdPS findings. Conclusion Although the PS-matched analysis suggested elevated though non-significant hazards of death among patients with no financial assistance during the gap, the hdPS analysis produced lower estimates that were stable across sensitivity analyses. PMID:22552984

Sustained use of biogas fuel and blood pressure among women in rural Nepal

PubMed Central

Neupane, Maniraj; Basnyat, Buddha; Fischer, Rainald; Froeschl, Guenter; Wolbers, Marcel; Rehfuess, Eva A

2015-01-01

Background More than two fifths of the world's population cook with solid fuels and are exposed to household air pollution (HAP). As of now, no studies have assessed whether switching to alternative fuels like biogas could impact cardiovascular health among cooks previously exposed to solid fuel use. Methods We conducted a propensity score matched cross-sectional study to explore if the sustained use of biogas fuel for at least ten years impacts blood pressure among adult female cooks of rural Nepal. We recruited one primary cook ≥30 years of age from each biogas (219 cooks) and firewood (300 cooks) using household and measured their systolic (SBP) and diastolic blood pressure (DBP). Household characteristics, kitchen ventilation and 24-h kitchen carbon monoxide were assessed. We matched cooks by age, body mass index and socio-economic status score using propensity scores and investigated the effect of biogas use through multivariate regression models in two age groups, 30–50 years and >50 years to account for any post-menopausal changes. Results We found substantially reduced 24-h kitchen carbon monoxide levels among biogas-using households. After matching and adjustment for smoking, kitchen characteristics, ventilation status and additional fuel use, the use of biogas was associated with 9.8 mmHg lower SBP [95% confidence interval (CI), −20.4 to 0.8] and 6.5 mmHg lower DBP (95% CI, −12.2 to −0.8) compared to firewood users among women >50 years of age. In this age group, biogas use was also associated with 68% reduced odds [Odds ratio 0.32 (95% CI, 0.14 to 0.71)] of developing hypertension. These effects, however, were not identified in younger women aged 30–50 years. Conclusions Sustained use of biogas for cooking may protect against cardiovascular disease by lowering the risk of high blood pressure, especially DBP, among older female cooks. These findings need to be confirmed in longitudinal or experimental studies. PMID:25460655

Infant Formula Feeding at Birth Is Common and Inversely Associated with Subsequent Breastfeeding Behavior in Vietnam123

PubMed Central

Nguyen, Tuan T; Withers, Mellissa; Hajeebhoy, Nemat; Frongillo, Edward A

2016-01-01

Background: The association between infant formula feeding at birth and subsequent feeding patterns in a low- or middle-income context is not clear. Objective: We examined the association of infant formula feeding during the first 3 d after birth with subsequent infant formula feeding and early breastfeeding cessation in Vietnam. Methods: In a cross-sectional survey, we interviewed 10,681 mothers with children aged 0−23 mo (mean age: 8.2 mo; 52% boys) about their feeding practices during the first 3 d after birth and on the previous day. We used stratified analysis, multiple logistic regression, propensity score-matching analysis, and structural equation modeling to minimize the limitation of the cross-sectional design and to ensure the consistency of the findings. Results: Infant formula feeding during the first 3 d after birth (50%) was associated with a higher prevalence of subsequent infant formula feeding [stratified analysis: 7−28% higher (nonoverlapping 95% CIs for most comparisons); propensity score-matching analysis: 13% higher (P < 0.001); multiple logistic regression: OR: 1.47 (95% CI: 1.30, 1.67)]. This practice was also associated with a higher prevalence of early breastfeeding cessation (e.g., <24 mo) [propensity score-matching analysis: 2% (P = 0.08); OR: 1.33 (95% CI: 1.12, 1.59)]. Structural equation modeling showed that infant formula feeding during the first 3 d after birth was associated with a higher prevalence of subsequent infant formula feeding (β: 0.244; P < 0.001), which in turn was linked to early breastfeeding cessation (β: 0.285; P < 0.001). Conclusions: Infant formula feeding during the first 3 d after birth was associated with increased subsequent infant formula feeding and the early cessation of breastfeeding, which underscores the need to make early, exclusive breastfeeding normative and to create environments that support it. PMID:27605404

Parent characteristics linked with daughters' attachment styles.

PubMed

Kilmann, Peter R; Vendemia, Jennifer M C; Parnell, Michele M; Urbaniak, Geoffrey C

2009-01-01

This study investigated links between parent characteristics and daughters' attachment styles for 90 female undergraduates and their married biological parents. Parents with a secure attachment pattern were rated as more accepting, less controlling, more competent, and more consistent in showing love and affection to their daughter in contrast to parents with an insecure attachment pattern. Significant positive associations were found between mothers' fearful attachment scores and the fearful, preoccupied, and dismissive attachment scores of daughters. Daughters of matched secure parents were more likely to report a secure attachment style, while daughters of matched insecure parents were more likely to report an insecure attachment style.

Expiratory and phonation times as measures of disease severity in patients with Multiple Sclerosis. A case-control study.

PubMed

Nordio, Sara; Bernitsas, Evanthia; Meneghello, Francesca; Palmer, Katie; Stabile, Maria Rosaria; Dipietro, Laura; Di Stadio, Arianna

2018-04-21

Speech disorders are common in patients with Multiple Sclerosis (MS). They can be assessed with several methods, which are however expensive, complex, and not easily accessible to physicians during routine clinic visits. This study aimed at measuring maximum phonation times, maximum expiratory times, and articulation abilities scores in patients with MS compared to healthy subjects and at investigating if any of these parameters could be used as a measure of MS progression. 50 MS patients and 50 gender- and age-matched healthy controls were enrolled in the study. Maximum expiratory times and maximum phonation times were collected from both groups. Articulation abilities were evaluated using the articulation subtest from the Fussi assessment (dysarthria scores). MS patients were evaluated with the Expanded Disability Status Scale (EDSS). Correlations between EDSS scores and maximum expiratory times, maximum phonation times, and dysarthria scores were calculated. EDSS scores of MS patients ranged from 4.5 to 7.5. In MS patients, maximum expiratory times, maximum phonation times, and dysarthria scores were significantly altered compared to healthy controls. Moreover, the EDSS scores were correlated with the maximum expiratory times; the maximum expiratory times were correlated with the maximum phonation times, and the maximum phonation times were correlated with the dysarthria scores. As the expiratory times were significantly correlated with the EDSS scores, they could be used to measure the severity of MS and to monitor its progression. Copyright © 2018 Elsevier B.V. All rights reserved.

The convergent and concurrent validity of trait-based prototype assessment of personality disorder categories in homeless persons.

PubMed

Samuel, Douglas B; Connolly, Adrian J; Ball, Samuel A

2012-09-01

The DSM-5 proposal indicates that personality disorders (PDs) be defined as collections of maladaptive traits but does not provide a specific diagnostic method. However, researchers have previously suggested that PD constructs can be assessed by comparing individuals' trait profiles with those prototypic of PDs and evidence from the five-factor model (FFM) suggests that these prototype matching scores converge moderately with traditional PD instruments. The current study investigates the convergence of FFM PD prototypes with interview-assigned PD diagnoses in a sample of 99 homeless individuals. This sample had very high rates of PDs, which extends previous research on samples with more modest prevalence rates. Results indicated that diagnostic agreement between these methods was generally low but consistent with the agreement previously observed between explicit PD measures. Furthermore, trait-based and diagnostic interview scores evinced similar relationships with clinically important indicators such as abuse history and past suicide attempts. These findings demonstrate the validity of prototype methods and suggest their consideration for assessing trait-defined PD types within DSM-5.

A Comparison of Repetitive Behaviors in Aspergers Disorder and High Functioning Autism

ERIC Educational Resources Information Center

Cuccaro, Michael L.; Nations, Laura; Brinkley, Jason; Abramson, Ruth K.; Wright, Harry H.; Hall, Alicia; Gilbert, John; Pericak-Vance, Margaret A.

2007-01-01

In this study we compared 33 IQ and age matched pairs of individuals with Aspergers Disorder (ASP) and high functioning autism (HFA) on measures of repetitive behavior. On the Repetitive Behavior Scale-Revised (RBS-R), the ASP and HFA groups showed no differences in RBS-R Intensity score (severity) score or Frequency score (number of problems…

Modification of the Mantel-Haenszel and Logistic Regression DIF Procedures to Incorporate the SIBTEST Regression Correction

ERIC Educational Resources Information Center

DeMars, Christine E.

2009-01-01

The Mantel-Haenszel (MH) and logistic regression (LR) differential item functioning (DIF) procedures have inflated Type I error rates when there are large mean group differences, short tests, and large sample sizes.When there are large group differences in mean score, groups matched on the observed number-correct score differ on true score,…

Narcissism in patients admitted to psychiatric acute wards: its relation to violence, suicidality and other psychopathology

PubMed Central

Svindseth, Marit F; Nøttestad, Jim Aage; Wallin, Juliska; Roaldset, John Olav; Dahl, Alv A

2008-01-01

Background The objective was to examine various aspects of narcissism in patients admitted to acute psychiatric wards and to compare their level of narcissism to that of an age- and gender-matched sample from the general population (NORM). Methods This cross-sectional study interviewed 186 eligible acute psychiatric patients with the Brief Psychiatric Rating Scale (BPRS) and the Global Assessment of Functioning (GAF). The patients filled in the Narcissistic Personality Inventory-21 item version (NPI-21), The Hospital Anxiety and Depression Scale (HADS) and the Rosenberg Self-Esteem Scale. High and low narcissism was defined by the median of the total NPI-21 score. An age- and gender-matched control sample from the general population also scored the NPI-21 (NORM). Results Being male, involuntary admitted, having diagnosis of schizophrenia, higher self-esteem, and severe violence were significantly associated with high narcissism, and so were also low levels of suicidality, depression, anxiety and GAF scores. Severe violence and high self-esteem were significantly associated with high narcissism in multivariable analyses. The NPI-21 and its subscales showed test-retest correlations ≥0.83, while the BPRS and the HADS showed lower correlations, confirming the trait character of the NPI-21. Depression and suicidality were negatively associated with the NPI-21 total score and all its subscales, while positive association was observed with grandiosity. No significant differences were observed between patients and NORM on the NPI-21 total score or any of the NPI subscales. Conclusion Narcissism in the psychiatric patients was significantly associated with violence, suicidality and other symptoms relevant for management and treatment planning. Due to its trait character, use of the NPI-21 in acute psychiatric patients can give important clinical information. The similar level of narcissism found in patients and NORM is in need of further examination. PMID:18304339

Outcomes for youth receiving intensive in-home therapy or residential care: a comparison using propensity scores.

PubMed

Barth, Richard P; Greeson, Johanna K P; Guo, Shenyang; Green, Rebecca L; Hurley, Sarah; Sisson, Jocelyn

2007-10-01

This study compares outcomes for behaviorally troubled children receiving intensive in-home therapy (IIHT) and those receiving residential care (RC). Propensity score matching is used to identify matched pairs of youth (n = 786) with equivalent propensity for IIHT. The majority of pretreatment differences between the IIHT and RC groups are eliminated following matching. Logistic regression is then conducted on outcome differences at 1 year postdischarge. Results show that IIHT recipients had a greater tendency (.615) toward living with family, making progress in school, not experiencing trouble with the law, and placement stability compared with RC youth (.558; p < .10). This suggests that IIHT is at least as effective for achieving positive outcomes. Given IIHT's reduced restrictiveness and cost, intensive in-home services should be the preferred treatment over RC in most cases.

Propensity Score Matching: Retrospective Randomization?

PubMed

Jupiter, Daniel C

Randomized controlled trials are viewed as the optimal study design. In this commentary, we explore the strength of this design and its complexity. We also discuss some situations in which these trials are not possible, or not ethical, or not economical. In such situations, specifically, in retrospective studies, we should make every effort to recapitulate the rigor and strength of the randomized trial. However, we could be faced with an inherent indication bias in such a setting. Thus, we consider the tools available to address that bias. Specifically, we examine matching and introduce and explore a new tool: propensity score matching. This tool allows us to group subjects according to their propensity to be in a particular treatment group and, in so doing, to account for the indication bias. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

A-MUPS score to differentiate patients with somatic symptom disorder from those with medical disease for complaints of non-acute pain.

PubMed

Suzuki, Shingo; Ohira, Yoshiyuki; Noda, Kazutaka; Ikusaka, Masatomi

2017-01-01

To develop a clinical score to discriminate patients with somatic symptom disorder (SSD) from those with medical disease (MD) for complaints of non-acute pain. We retrospectively examined the clinical records of consecutive patients with pain for a duration of ≥1 month in our department from April 2003 to March 2015. We divided the subjects according to the diagnoses of definite SSD (as diagnosed and tracked by psychiatrists in our hospital), probable SSD (without evaluation by psychiatrists in our hospital), matched MD (randomly matched two patients by age, sex, and pain location for each definite SSD patient), unmatched MD, other mental disease, or functional somatic syndrome (FSS). We investigated eight clinical factors for definite SSD and matched MD, and developed a diagnostic score to identify SSD. We subsequently validated the model with cases of probable SSD and unmatched MD. The number of patients with definite SSD, probable SSD, matched MD, unmatched MD, other mental disease, and FSS was 104 (3.5%), 214 (7.3%), 197 (6.7%), 742 (25%), 708 (24%), and 978 (33%), respectively. In a conditional logistic regression analysis, the following five factors were included as independent predictors of SSD: Analgesics ineffective, Mental disorder history, Unclear provocative/palliative factors, Persistence without cessation, and Stress feelings/episodes (A-MUPS). The area under the receiver operating characteristic curve (AUC) of the model was 0.900 (95% CI: 0.864-0.937, p <0.001), and the McFadden's pseudo- R -squared was 0.709. For internal validation, the AUC between probable SSD and unmatched MD was 0.930 (95% CI: 0.910-0.950, p <0.001). The prevalence and the likelihood ratio of SSD increased as the score increased. The A-MUPS score was useful for discriminating patients with SSD from those with MD for complaints of non-acute pain, although external validation and refinement should be needed.

Risk of infectious complications associated with blood transfusion in elective spinal surgery-a propensity score matched analysis.

PubMed

Kato, So; Chikuda, Hirotaka; Ohya, Junichi; Oichi, Takeshi; Matsui, Hiroki; Fushimi, Kiyohide; Takeshita, Katsushi; Tanaka, Sakae; Yasunaga, Hideo

2016-01-01

Although the negative aspects of blood transfusion are increasingly recognized, less is known about transfusion-related risks in spinal surgery. This study was designed to determine whether perioperative allogeneic blood transfusion is associated with increased risk of infectious complications after elective spinal surgery. A retrospective cohort study with propensity score matched analysis was carried out. Data of patients with spinal canal stenosis and spondylolisthesis who underwent elective lumbar surgeries (decompression or fusion) were obtained from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan. Clinical outcomes included in-hospital death and the occurrence of infectious complications (surgical site infection [SSI], respiratory tract infection, urinary tract infection, and sepsis). Patients' clinical information, including sex, age, type of hospital, preoperative comorbidities, duration of anesthesia, cell saver use, and volume of allogeneic blood transfused, were investigated. Patients transfused with >840 mL (6 units) were excluded. Propensity scores for receiving transfusion were calculated, with one-to-one matching based on estimated propensity scores to adjust for patients' baseline characteristics. The proportions of complications were compared in patients with and without transfusions. This study was funded by grants from the Ministry of Health, Labour and Welfare, Japan. Of the 84,650 patients identified, 5,289 patients (6.1%) received transfusions, with 4,436 (5.2%) receiving up to 840 mL. One-to-one propensity score matching resulted in 4,275 pairs with and without transfusion. Patients transfused were at increased risk of SSI (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.4-2.5; p<.001) and urinary tract infection (OR, 2.5; 95% CI, 1.5-4.2; p<.001) than those not transfused. Allogeneic blood transfusion after elective lumbar surgery was associated with increased risks of SSI and urinary tract infection. Copyright © 2015 Elsevier Inc. All rights reserved.

The Reliability of Facial Recognition of Deceased Persons on Photographs.

PubMed

Caplova, Zuzana; Obertova, Zuzana; Gibelli, Daniele M; Mazzarelli, Debora; Fracasso, Tony; Vanezis, Peter; Sforza, Chiarella; Cattaneo, Cristina

2017-09-01

In humanitarian emergencies, such as the current deceased migrants in the Mediterranean, antemortem documentation needed for identification may be limited. The use of visual identification has been previously reported in cases of mass disasters such as Thai tsunami. This pilot study explores the ability of observers to match unfamiliar faces of living and dead persons and whether facial morphology can be used for identification. A questionnaire was given to 41 students and five professionals in the field of forensic identification with the task to choose whether a facial photograph corresponds to one of the five photographs in a lineup and to identify the most useful features used for recognition. Although the overall recognition score did not significantly differ between professionals and students, the median scores of 78.1% and 80.0%, respectively, were too low to consider this method as a reliable identification method and thus needs to be supported by other means. © 2017 American Academy of Forensic Sciences.

GRIDSS: sensitive and specific genomic rearrangement detection using positional de Bruijn graph assembly

PubMed Central

Do, Hongdo; Molania, Ramyar

2017-01-01

The identification of genomic rearrangements with high sensitivity and specificity using massively parallel sequencing remains a major challenge, particularly in precision medicine and cancer research. Here, we describe a new method for detecting rearrangements, GRIDSS (Genome Rearrangement IDentification Software Suite). GRIDSS is a multithreaded structural variant (SV) caller that performs efficient genome-wide break-end assembly prior to variant calling using a novel positional de Bruijn graph-based assembler. By combining assembly, split read, and read pair evidence using a probabilistic scoring, GRIDSS achieves high sensitivity and specificity on simulated, cell line, and patient tumor data, recently winning SV subchallenge #5 of the ICGC-TCGA DREAM8.5 Somatic Mutation Calling Challenge. On human cell line data, GRIDSS halves the false discovery rate compared to other recent methods while matching or exceeding their sensitivity. GRIDSS identifies nontemplate sequence insertions, microhomologies, and large imperfect homologies, estimates a quality score for each breakpoint, stratifies calls into high or low confidence, and supports multisample analysis. PMID:29097403

Calcium supplementation improves clinical outcome in intensive care unit patients: a propensity score matched analysis of a large clinical database MIMIC-II.

PubMed

Zhang, Zhongheng; Chen, Kun; Ni, Hongying

2015-01-01

Observational studies have linked hypocalcemia with adverse clinical outcome in critically ill patients. However, calcium supplementation has never been formally investigated for its beneficial effect in critically ill patients. To investigate whether calcium supplementation can improve 28-day survival in adult critically ill patients. Secondary analysis of a large clinical database consisting over 30,000 critical ill patients was performed. Multivariable analysis was performed to examine the independent association of calcium supplementation and 28-day morality. Furthermore, propensity score matching technique was employed to investigate the role of calcium supplementation in improving survival. none. Primary outcome was the 28-day mortality. 90-day mortality was used as secondary outcome. A total of 32,551 adult patients, including 28,062 survivors and 4489 non-survivors (28-day mortality rate: 13.8 %) were included. Calcium supplementation was independently associated with improved 28-day mortality after adjusting for confounding variables (hazard ratio: 0.51; 95 % CI 0.47-0.56). Propensity score matching was performed and the after-matching cohort showed well balanced covariates. The results showed that calcium supplementation was associated with improved 28- and 90-day mortality (p < 0.05 for both Log-rank test). In adult critically ill patients, calcium supplementation during their ICU stay improved 28-day survival. This finding supports the use of calcium supplementation in critically ill patients.

On the Bias-Amplifying Effect of Near Instruments in Observational Studies

ERIC Educational Resources Information Center

Steiner, Peter M.; Kim, Yongnam

2014-01-01

In contrast to randomized experiments, the estimation of unbiased treatment effects from observational data requires an analysis that conditions on all confounding covariates. Conditioning on covariates can be done via standard parametric regression techniques or nonparametric matching like propensity score (PS) matching. The regression or…

Predicting Rapid Relapse Following Treatment for Chemical Dependence: A Matched-Subjects Design.

ERIC Educational Resources Information Center

Svanum, Soren; McAdoo, William George

1989-01-01

Persons who underwent residential treatment for chemical dependency were identified as three-month treatment failures (N=52) or successes (N=52). Subjects were matched on Minnesota Multiphasic Personality Inventory (MMPI) scores. Found posttreatment depression, anxiety, and sleep problems strongly related to failure among psychiatric MMPI group;…

A Logistic Regression Analysis of Score Sending and College Matching among High School Students

ERIC Educational Resources Information Center

Oates, Krystle S.

2015-01-01

College decisions are often the result of a variety of influences related to student background characteristics, academic characteristics, college preferences and college aspirations. College counselors recommend that students choose a variety of schools, especially schools where the general student body matches the academic achievement of…

Matching Alcoholics to Coping Skills or Interactional Therapies: Two-Year Follow-Up Results.

ERIC Educational Resources Information Center

Cooney, Ned L.; And Others

1991-01-01

Assigned 96 inpatients in alcoholism treatment to aftercare group treatment with either coping skills training or interactional therapy. Survival analyses using two-year outcome data provided evidence for durability of matching interaction effects. Individuals scoring high on sociopathy or global psychopathology had better outcomes in coping…

Fast Mapping Word-Learning Abilities of Language-Delayed Preschoolers.

ERIC Educational Resources Information Center

Rice, Mabel L.; And Others

1990-01-01

Twenty language-delayed children (age three to six) viewed a presentation incorporating object, action, attribute, and affective state words into a narrative script. In pre- and postviewing word comprehension measurements, subjects scored lower than children matched for chronological age and children matched for mean length of utterance.…

BiobankConnect: software to rapidly connect data elements for pooled analysis across biobanks using ontological and lexical indexing

PubMed Central

Pang, Chao; Hendriksen, Dennis; Dijkstra, Martijn; van der Velde, K Joeri; Kuiper, Joel; Hillege, Hans L; Swertz, Morris A

2015-01-01

Objective Pooling data across biobanks is necessary to increase statistical power, reveal more subtle associations, and synergize the value of data sources. However, searching for desired data elements among the thousands of available elements and harmonizing differences in terminology, data collection, and structure, is arduous and time consuming. Materials and methods To speed up biobank data pooling we developed BiobankConnect, a system to semi-automatically match desired data elements to available elements by: (1) annotating the desired elements with ontology terms using BioPortal; (2) automatically expanding the query for these elements with synonyms and subclass information using OntoCAT; (3) automatically searching available elements for these expanded terms using Lucene lexical matching; and (4) shortlisting relevant matches sorted by matching score. Results We evaluated BiobankConnect using human curated matches from EU-BioSHaRE, searching for 32 desired data elements in 7461 available elements from six biobanks. We found 0.75 precision at rank 1 and 0.74 recall at rank 10 compared to a manually curated set of relevant matches. In addition, best matches chosen by BioSHaRE experts ranked first in 63.0% and in the top 10 in 98.4% of cases, indicating that our system has the potential to significantly reduce manual matching work. Conclusions BiobankConnect provides an easy user interface to significantly speed up the biobank harmonization process. It may also prove useful for other forms of biomedical data integration. All the software can be downloaded as a MOLGENIS open source app from http://www.github.com/molgenis, with a demo available at http://www.biobankconnect.org. PMID:25361575

Minnesota multiphasic personality inventory-2 restructured form (MMPI-2-RF) scale score differences in bariatric surgery candidates diagnosed with binge eating disorder versus BMI-matched controls.

PubMed

Marek, Ryan J; Ben-Porath, Yossef S; Ashton, Kathleen; Heinberg, Leslie J

2014-04-01

Binge Eating Disorder (BED) is among the most common psychiatric disorders in bariatric surgery candidates. The Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF) is a broadband, psychological test that includes measures of emotional and behavioral dysfunction, which have been associated with BED behaviors in bariatric surgery candidates; however these studies have lacked appropriate controls. In the current study, we compared MMPI-2-RF scale scores of bariatric surgery patients diagnosed with BED (BED+) with BMI-matched controls without BED (BED-). Three-hundred and seven BED+ participants (72.64% female and 67.87% Caucasian; mean BMI of 51.36 kg/m(2) [SD = 11.94]) were drawn from a large, database (N = 1304). Three-hundred and seven BED- participants were matched on BMI and demographics (72.64% female, 68.63% Caucasian, and mean BMI of 51.30 kg/m(2) [SD = 11.70]). The BED+ group scored significantly higher on measures of Demoralization, Low Positive Emotions, and Dysfunctional Negative Emotions and scored lower on measures of Antisocial Behaviors, reflecting behavioral constraint. Optimal T-Score cutoffs were below the traditional 65 T score for several MMPI-2-RF scales. MMPI-2-RF externalizing measures also added incrementally to differentiating between the groups beyond the Binge Eating Scale (BES). BED+ individuals produced greater elevations on a number of MMPI-2-RF internalizing scales and externalizing scales. Use of the test in conjunction with a clinical interview and other self-report data can further aid the clinician in guiding patients to appropriate treatment to optimize outcome. Copyright © 2013 Wiley Periodicals, Inc.

Representation of ophthalmology concepts by electronic systems: adequacy of controlled medical terminologies.

PubMed

Chiang, Michael F; Casper, Daniel S; Cimino, James J; Starren, Justin

2005-02-01

To assess the adequacy of 5 controlled medical terminologies (International Classification of Diseases 9, Clinical Modification [ICD9-CM]; Current Procedural Terminology 4 [CPT-4]; Systematized Nomenclature of Medicine, Clinical Terms [SNOMED-CT]; Logical Identifiers, Names, and Codes [LOINC]; Medical Entities Dictionary [MED]) for representing concepts in ophthalmology. Noncomparative case series. Twenty complete ophthalmology case presentations were sequentially selected from a publicly available ophthalmology journal. Each of the 20 cases was parsed into discrete concepts, and each concept was classified along 2 axes: (1) diagnosis, finding, or procedure and (2) ophthalmic or medical concept. Electronic or paper browsers were used to assign a code for every concept in each of the 5 terminologies. Adequacy of assignment for each concept was scored on a 3-point scale. Findings from all 20 case presentations were combined and compared based on a coverage score, which was the average score for all concepts in that terminology. Adequacy of assignment for concepts in each terminology, based on a 3-point Likert scale (0, no match; 1, partial match; 2, complete match). Cases were parsed into 1603 concepts. SNOMED-CT had the highest mean overall coverage score (1.625+/-0.667), followed by MED (0.974+/-0.764), LOINC (0.781+/-0.929), ICD9-CM (0.280+/-0.619), and CPT-4 (0.082+/-0.337). SNOMED-CT also had higher coverage scores than any of the other terminologies for concepts in the diagnosis, finding, and procedure categories. Average coverage scores for ophthalmic concepts were lower than those for medical concepts. Controlled terminologies are required for electronic representation of ophthalmology data. SNOMED-CT had significantly higher content coverage than any other terminology in this study.

Venous thromboembolism after induced abortion: a population-based, propensity-score-matched cohort study in Canada.

PubMed

Liu, Ning; Vigod, Simone N; Farrugia, M Michèle; Urquia, Marcelo L; Ray, Joel G

2018-06-08

A woman's risk of venous thromboembolism during pregnancy is estimated to be two-to-six times higher than her risk when she is not pregnant. Such risk estimates are largely based on pregnancies that result in delivery of a newborn baby; no estimates exist for the risk of venous thromboembolism after induced abortion, another common pregnancy outcome. To fill this knowledge gap, we aimed to assess the risk of venous thromboembolism in women whose first pregnancy ended with induced abortion. We did this propensity score-matched cohort study using data from the universal health-care system of Ontario, Canada. We included primigravid women who had an induced abortion between Jan 1, 2003, and Dec 31, 2015, and used a propensity score to match them to primigravid women who had a livebirth (1:1) or nulligravid women who were not pregnant on the procedure date of their matched counterpart and who did not conceive within 1 year afterwards (5:1). We excluded from our analysis women younger than 15 years or older than 49 years and individuals who had missing or invalid information about their sex, area of residence, residential income, or world region of origin. The primary outcome was risk of any venous thromboembolism within 42 days of the index date (defined as the date of an induced abortion, delivery date for livebirth, or for non-pregnant women the induced abortion date of their matched counterpart). We compared the rate of venous thromboembolism in primigravid women who had an induced abortion with the rate of venous thromboembolism in propensity-score-matched non-pregnant women and propensity-score-matched primigravid women whose pregnancy ended with a livebirth. We generated hazard ratios (HRs) of 42-day risk of venous thromboembolism after induced abortion using Cox proportional hazard models. We identified 194 086 eligible women whose first pregnancy ended with induced abortion, of whom 176 001 (90·7%) could be matched with women whose first pregnancy ended in delivery of a newborn. These 176 001 women were also matched to 880 005 non-pregnant women. The rate of venous thromboembolism within 42 days of an induced abortion was 30·1 (95% CI 22·0-38·2) per 100 000 women compared with 13·5 (11·1-16·0) per 100 000 women in the non-pregnant group (HR 2·23, 95% CI 1·61-3·08). The HR was 0·16 (95% CI 0·12-0·22) when compared with the women in the livebirth cohort, whose venous thromboembolism rate within 42 days postpartum was 184·7 (95% CI 164·6-204·7) per 100 000 women. The 42-day risk of venous thromboembolism after an induced abortion is double that of a matched non-pregnant woman, and is significantly lower than after a livebirth. This novel information can inform estimates of peri-procedural risk of venous thromboembolism after induced abortion. Clinicians could consider a lower threshold for ordering a diagnostic test to rule out venous thromboembolism after induced abortion than they would in a non-pregnant woman. Institute for Clinical Evaluative Sciences. Copyright © 2018 Elsevier Ltd. All rights reserved.

A novel robotic surgical technique for thyroid surgery: bilateral axillary approach (BAA).

PubMed

Woo, Jung-Woo; Kim, Seo Ki; Park, Inhye; Choe, Jun Ho; Kim, Jung-Han; Kim, Jee Soo

2017-02-01

Bilateral axillo-breast approach (BABA) robotic thyroidectomy (RT) is proven to be a feasible method for the treatment of well-differentiated thyroid cancers in terms of oncology as well as cosmesis. However, BABA RT causes postoperative sternal discomfort and needs an incision over the nipple areolar area. Here, we suggest a novel robotic surgical technique for thyroid surgery that does not need a breast incision-bilateral axillary approach (BAA). We recruited 51 patients who were willing to undergo the novel BAA robotic thyroid surgery. We performed a propensity score-matched analysis to compare the BAA robotic thyroid surgery group (BAA group) with the conventional open thyroid surgery group (open group). Mean operation time in the BAA group (129.7 min) was significantly longer than that in the open group (103.1 min) (p < 0.001). However, no significant differences in the mean number of metastatic lymph nodes (LNs), mean number of retrieved LNs, vocal cord palsy, hypoparathyroidism, and mean stimulated thyroglobulin level were observed between the two groups. There was no case of postoperative bleeding or chyle leak. Of the 51 patients who had undergone the BAA procedure, 27 patients answered the questionnaire. The mean scale, ranging from 0 to 10, at postoperative 1 day/2 weeks was as follows: voice change score, 3.0/1.6; swallowing difficulty score, 4.0/2.0; anterior neck pain score, 4.6/3.6; anterior neck numbness score, 5.4/4.3; right chest pain score, 3.8/2.1; left chest pain score, 3.6/2.3; right chest numbness score, 3.2/2.8; left chest numbness score, 2.4/2.7; right breast pain score, 0.9/0; left breast pain score, 1.2/0; right breast numbness score, 1.7/0; and left breast numbness score, 2.6/0, respectively. BAA robotic thyroid surgery is a novel, safe, and feasible oncoplastic method, especially for patients who have fear of procedures around the nipple areolar complex.

Long-term outcome of social skills intervention based on interactive LEGO play.

PubMed

Legoff, Daniel B; Sherman, Michael

2006-07-01

LEGO building materials have been adapted as a therapeutic modality for increasing motivation to participate in social skills intervention, and providing a medium through which children with social and communication handicaps can effectively interact. A 3 year retrospective study of long-term outcome for autistic spectrum children participating in LEGO therapy (N = 60) compared Vineland Adaptive Behavior Scale socialization domain (VABS-SD) and Gilliam Autism Rating Scale social interaction subscale (GARS-SI) scores preand post-treatment with a matched comparison sample (N = 57) who received comparable non-LEGO therapy. Although both groups made significant gains on the two outcome measures, LEGO participants improved significantly more than the comparison subjects. Diagnosis and pre-treatment full-scale IQ scores did not predict outcome scores; however, Vineland adaptive behavior composite, Vineland communication domain, and verbal IQ all predicted outcome on the VABS-SD, especially for the LEGO therapy group. Results are discussed in terms of implications for methods of social skills intervention for autistic spectrum disorders.