Physical Sciences and Mathematics Commons^™

Integrated Analysis Of Content And Construct Validity, Byron Gajewski, Larry Price, Valorie Coffland, Diane Boyle, Marjorie Bott

Diane Kay Boyle PhD, RN, FAAN

Establishing adequacy of psychometric properties of an instrument involves acquisition and evaluation of evidence based on item content and internal structure. Content validity evidence consists of subject matter experts providing quantitative ratings of the extent to which items are a representative sample of targeted domain. Evidence of internal structure includes factor analytic studies and examination of item interrelationships based on item responses from participants. Although subject matter expert ratings and participant response data are traditionally analyzed separately, each serves to inform the other in important ways. We propose integrating subject matter experts’ and participants’ data seamlessly to establish a unified …

Adjusting Medicare Capitation Payments Using Prior Hospitalization Data, Arlene Ash, Frank Porell, Leonard Gruenberg, Eric Sawitz, Alexa Beiser

Frank Porell

The diagnostic cost group approach to a reimbursement model for health maintenance organizations is presented. Diagnostic information about previous hospitalizations is used to create empirically determined risk groups, using only diagnoses involving little or no discretion in the decision to hospitalize. Diagnostic cost group and other models (including Medicare's current formula and other prior-use models) are tested for their ability to predict future costs, using R2 values and new measures of predictive performance. The diagnostic cost group models perform relatively well with respect to a range of criteria, including administrative feasibility, resistance to provider manipulation, and statistical accuracy.

Testing For Improvement In Prediction Model Performance, Margaret S. Pepe Phd, Kathleen F. Kerr Phd, Gary Longton, Zheyu Wang Phd

Margaret S Pepe PhD

New methodology has been proposed in recent years for evaluating the improvement in prediction performance gained by adding a new predictor, Y, to a risk model containing a set of baseline predictors, X, for a binary outcome D. We prove theoretically that null hypotheses concerning no improvement in performance are equivalent to the simple null hypothesis that the coefficient for Y is zero in the risk model, P(D=1|X,Y). Therefore, testing for improvement in prediction performance is redundant if Y has already been shown to be a risk factor. We investigate properties of tests through simulation studies, focusing on the change …

Introducing Functional Data Analysis To Neuroimaging, And Vice Versa, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Beyond Multiple Regression: Using Commonality Analysis To Better Understand R2 Results, Russell Warne

Russell T Warne

Multiple regression is one of the most common statistical methods used in quantitative educational research. Despite the versatility and easy interpretability of multiple regression, it has some shortcomings in the detection of suppressor variables and for somewhat arbitrarily assigning values to the structure coefficients of correlated independent variables. Commonality analysis—heretofore rarely used in gifted education research—is a statistical method that partitions the explained variance of a dependent variable into nonoverlapping parts according to the independent variable(s) that are related to each portion. This Methodological Brief includes an example of commonality analysis and equations for researchers who wish to conduct their …

Diabetes Prediction In Pima Indians Using Ann And Statistical Techniques, Kuldeep Kumar, Ping Zhang

Kuldeep Kumar

Due to the fact that Pima Indian tribe has lived in the same location for an unmitigated number of years, a vast source of information of these people has been gained, which helps researchers for the study of diabetes and possible genetic factors of the disease. In this paper, we use Artificial Neural Network (ANN) and some statistical techniques for the prediction of diabetes. All the prediction models are evaluated with ROC curves.

How To Make Teaching Of Statistics More Effective In Business Schools?, Kuldeep Kumar

Kuldeep Kumar

Statistics is taught in almost all Business Schools as a core course and prerequisite to may advance economics, finance and accountancy courses. However, Statistics has to be taught in a different way in Business Schools as compared to how it is taught in their own statistics department. There should be more emphasis on applications in Business area rather than theory. There has been lot of interest in teaching of statistics in Business schools for a very long time, for example see Cox (1965), Moore (1976) and Love and Hildebrand (2002). This paper discusses author's experience of teaching statistics in an …

A Brief Review Of Recent Research Trends On Applications Of Computational And Statistical Techniques In Financial & Business Intelligence, Kuldeep Kumar, Sukanto Bhattacharya

Kuldeep Kumar

Artificial neural networks and statistical techniques like decision trees,discriminant analysis, logistic regression and survival analysis play a crucial role in Business Intelligence. These predictive analytical tools exploit patterns found in historical data to make predictions about future events. In this paper we have shown some recent developments of a few of these techniques in financial and business intelligence applications like fraud detection, bankruptcy prediction and credit rating scoring.

When Is Informed Consent Required In Cluster Randomized Trials In Health Research?, Andrew Mcrae, Charles Weijer, Ariella Binik, Jeremy Grimshaw, Robert Boruch, Jamie Brehaut, Allan Donner, Martin P Eccles, Raphael Saginur, Angela White, Monica Taljaard

Charles Weijer

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the second of the questions posed, namely, from whom, when, and how must informed consent be obtained in CRTs in health research? The ethical principle of respect for persons implies that researchers are generally obligated to obtain the informed consent of research subjects. Aspects of CRT …

Advancing Stage Of Female Reproductive Life Associated With Bipolar Illness Exacerbation, Wendy K. Marsh, Terence Ketter, Sybil L. Crawford, Julia V. Johnson, Anthony J. Rothschild

Sybil L. Crawford

Introduction: Perimenopause confers an increased risk of depression in the general population, yet bipolar disorder mood course remains unknown. Methods: Clinic visits in 519 premenopausal, 116 perimenopausal including 13 women transitioning from peri- to postmenopause, and 133 postmenopausal women with bipolar disorder who received naturalistic treatment in the multisite STEP-Bipolar Disorder study over 19.8 +/- 15.5 months were analyzed for mood state. Results: Advancing female reproductive stage was associated with significant decline in mood elevation; significant decline in euthymia; no significant difference in major depression; and symptomatic significant increase. Conclusions: Advancing stage of female reproductive life was associated with bipolar …

The Effects Of 24 Weeks Of Resistance Training With Simultaneous Elastic And Free Weight Loading On Muscular Performance Of Novice Lifters, Todd C. Shoepe, David A. Ramirez, Robert J. Rovetti, David R. Kohler, Hawley C. Almstedt

Hawley Almstedt

The purpose of this investigation was to assess the effectiveness of variable resistance as provided through elastic plus free weight techniques in college aged males and females. Twenty novice lifters were randomly assigned to a traditional free weight only (6 males and 5 females) or elastic band plus free weight group (5 males and 5 females) and 9 more normally active controls (5 males and 4 females), were recruited to maintain normal activity for the duration of the study. No differences existed between control, free weight and elastic band at baseline for age, body height, body mass, body mass index, …

The Effects Of 24 Weeks Of Resistance Training With Simultaneous Elastic And Free Weight Loading On Muscular Performance Of Novice Lifters, Todd C. Shoepe, David A. Ramirez, Robert J. Rovetti, David R. Kohler, Hawley C. Almstedt

Robert J. Rovetti

The purpose of this investigation was to assess the effectiveness of variable resistance as provided through elastic plus free weight techniques in college aged males and females. Twenty novice lifters were randomly assigned to a traditional free weight only (6 males and 5 females) or elastic band plus free weight group (5 males and 5 females) and 9 more normally active controls (5 males and 4 females), were recruited to maintain normal activity for the duration of the study. No differences existed between control, free weight and elastic band at baseline for age, body height, body mass, body mass index, …

The Effects Of 24 Weeks Of Resistance Training With Simultaneous Elastic And Free Weight Loading On Muscular Performance Of Novice Lifters, Todd C. Shoepe, David A. Ramirez, Robert J. Rovetti, David R. Kohler, Hawley C. Almstedt

Todd Shoepe

The purpose of this investigation was to assess the effectiveness of variable resistance as provided through elastic plus free weight techniques in college aged males and females. Twenty novice lifters were randomly assigned to a traditional free weight only (6 males and 5 females) or elastic band plus free weight group (5 males and 5 females) and 9 more normally active controls (5 males and 4 females), were recruited to maintain normal activity for the duration of the study. No differences existed between control, free weight and elastic band at baseline for age, body height, body mass, body mass index, …

Who Is The Research Subject In Cluster Randomized Trials In Health Research?, Andrew Mcrae, Charles Weijer, Ariella Binik, Angela White, Jeremy Grimshaw, Robert Boruch, Jamie Brehaut, Allan Donner, Martin Eccles, Raphael Saginur, Merrick Zwarenstein, Monica Taljaard

Charles Weijer

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the CRT is to be set on a firm ethical foundation. This paper addresses the first of the questions posed, namely, who is the research subject in a CRT in health research? The identification of human research subjects is logically prior to the application of protections as set out in research ethics and regulation. Aspects of CRT design, including the fact …

Asymptotic Theory For Cross-Validated Targeted Maximum Likelihood Estimation, Wenjing Zheng, Mark J. Van Der Laan

Wenjing Zheng

We consider a targeted maximum likelihood estimator of a path-wise differentiable parameter of the data generating distribution in a semi-parametric model based on observing n independent and identically distributed observations. The targeted maximum likelihood estimator (TMLE) uses V-fold sample splitting for the initial estimator in order to make the TMLE maximally robust in its bias reduction step. We prove a general theorem that states asymptotic efficiency (and thereby regularity) of the targeted maximum likelihood estimator when the initial estimator is consistent and a second order term converges to zero in probability at a rate faster than the square root of …

Asean+3 Monetary And Financial Integration: What We Need For A New Framework?, Reza Moosavi Mohseni

Reza Moosavi Mohseni

In this paper at first we investigate the viability of creating an optimum currency area (OCA) in the East Asia. Then we try to find the currency bloc which is more suitable for this region. A ten-variable VAR model employed to estimate the underlying shocks and test the symmetry of them. The results show that forming an OCA for all of the countries in the region is costly and difficult to sustain. But at first five countries called Japan, China, Korea, Malaysia, and the Philippine with symmetric supply shocks can create the single currency area. The rest of the countries …

Massively Parallel Nonparametrics [Hds 2011 Slides], Philip T. Reiss, Lei Huang

Philip T. Reiss

No abstract provided.

Flexible Dependence Of Functional Responses On Scalar Predictors, Philip T. Reiss, Lei Huang

Philip T. Reiss

No abstract provided.

Brief Of Amicus Curiae In Support Of Affirmance, Ron D. Katznelson

Ron D. Katznelson

No abstract provided.

Bayesian Mixtures Of Autoregressive Models, Sally Wood, Ori Rosen, Robert Kohn

Sally Wood

In this paper we propose a class of time-domain models for analyzing possibly nonstationary time series. This class of models is formed as a mixture of time series models, whose mixing weights are a function of time. We consider specifically mixtures of autoregressive models with a common but unknown lag. The model parameters, including the number of mixture components, are estimated via Markov chain Monte Carlo methods. The methodology is illustrated with simulated and real data.

30-Year Trends In Heart Failure In Patients Hospitalized With Acute Myocardial Infarction, David Mcmanus, Marcello Chinali, Jane Saczynski, Joel Gore, Jorge Yarzebski, Frederick Spencer, Darleen Lessard, Robert Goldberg

Jorge L. Yarzebski

Despite significant advances in its treatment, acute myocardial infarction (AMI) remains an important cause of heart failure (HF). Contemporary data remain lacking, however, describing long-term trends in incidence rates, demographic and clinical profiles, and outcomes of patients who develop HF as a complication of AMI. Our study sample consisted of 11,061 residents of the Worcester (Massachusetts) metropolitan area hospitalized with AMI at all greater Worcester hospitals in 15 annual study periods from 1975 to 2005. Overall, 32.4% of patients (n = 3,582) with AMI developed new-onset HF during their acute hospitalization. Patients who developed HF were generally older, more likely …

Recent Trends In The Incidence, Treatment, And Outcomes Of Patients With Stemi And Nstemi, David Mcmanus, Joel Gore, Jorge Yarzebski, Frederick Spencer, Darleen Lessard, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: despite the widespread use of electrocardiographic changes to characterize patients presenting with acute myocardial infarction, little is known about recent trends in the incidence rates, treatment, and outcomes of patients admitted for acute myocardial infarction further classified according to the presence of ST-segment elevation. The objectives of this population-based study were to examine recent trends in the incidence and death rates associated with the 2 major types of acute myocardial infarction in residents of a large central Massachusetts metropolitan area. METHODS: We reviewed the medical records of 5383 residents of the Worcester (MA) metropolitan area hospitalized for either ST-segment …

Declining Length Of Stay For Patients Hospitalized With Ami: Impact On Mortality And Readmissions, Jane Saczynski, Darleen Lessard, Frederick Spencer, Jerry Gurwitz, Joel Gore, Jorge Yarzebski, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Length of hospital stay after acute myocardial infarction decreased significantly in the 1980s and 1990s. Whether length of stay has continued to decrease during the 2000s, and the impact of decreasing length of stay on rehospitalization and mortality, is unclear. We describe decade-long (1995-2005) trends in length of stay after acute myocardial infarction, and examine whether declining length of stay has impacted early rehospitalization and postdischarge mortality in a population-based sample of hospitalized patients.

METHODS: The study sample consisted of 4184 patients hospitalized with acute myocardial infarction in a central New England metropolitan area during 6 annual periods (1995, …

Management And Outcomes Of Renal Disease And Acute Myocardial Infarction, Paul Santolucito, Dennis Tighe, David Mcmanus, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Contemporary trends in the management and outcomes of chronic kidney disease patients who develop an acute myocardial infarction have not been adequately described, particularly from the more generalizable perspective of a population-based investigation. METHODS: The study population consisted of 6219 residents of the Worcester, Massachusetts, metropolitan area who were hospitalized with acute myocardial infarction in 6 annual periods between 1995 and 2005. Patients were categorized as having preserved kidney function (n=3154), mild to moderate chronic kidney disease (n=2313), or severe chronic kidney disease (n=752) at the time of hospital admission. RESULTS: Patients with chronic kidney disease were more likely …

Clustering With Exclusion Zones: Genomic Applications, Mark Segal, Yuanyuan Xiao, Fred Huffer

Mark R Segal

Methods for formally evaluating the clustering of events in space or time, notably the scan statistic, have been richly developed and widely applied. In order to utilize the scan statistic and related approaches, it is necessary to know the extent of the spatial or temporal domains wherein the events arise. Implicit in their usage is that these domains have no “holes”—hereafter “exclusion zones”—regions in which events a priori cannot occur. However, in many contexts, this requirement is not met. When the exclusion zones are known, it is straightforward to correct the scan statistic for their occurrence by simply adjusting the …

Rejoinder: Estimation Issues For Copulas Applied To Marketing Data, Peter Danaher, Michael Smith

Michael Stanley Smith

Estimating copula models using Bayesian methods presents some subtle challenges, ranging from specification of the prior to computational tractability. There is also some debate about what is the most appropriate copula to employ from those available. We address these issues here and conclude by discussing further applications of copula models in marketing.

Forecasting Television Ratings, Peter Danaher, Tracey Dagger, Michael Smith

Michael Stanley Smith

Despite the state of flux in media today, television remains the dominant player globally for advertising spend. Since television advertising time is purchased on the basis of projected future ratings, and ad costs have skyrocketed, there is increasing pressure to forecast television ratings accurately. Previous forecasting methods are not generally very reliable and many have not been validated, but more distressingly, none have been tested in today’s multichannel environment. In this study we compare 8 different forecasting models, ranging from a naïve empirical method to a state-of-the-art Bayesian model-averaging method. Our data come from a recent time period, 2004-2008 in …

Cross-Validated Targeted Minimum-Loss-Based Estimation, Wenjing Zheng, Mark Van Der Laan

Wenjing Zheng

No abstract provided.

Accurately Sized Test Statistics With Misspecified Conditional Homoskedasticity, Douglas Steigerwald, Jack Erb

Douglas G. Steigerwald

We study the finite-sample performance of test statistics in linear regression models where the error dependence is of unknown form. With an unknown dependence structure there is traditionally a trade-off between the maximum lag over which the correlation is estimated (the bandwidth) and the amount of heterogeneity in the process. When allowing for heterogeneity, through conditional heteroskedasticity, the correlation at far lags is generally omitted and the resultant inflation of the empirical size of test statistics has long been recognized. To allow for correlation at far lags we study test statistics constructed under the possibly misspecified assumption of conditional homoskedasticity. …

The Underground Economy Of Fake Antivirus Software, Douglas Steigerwald, Brett Stone-Gross, Ryan Abman, Richard Kemmerer, Christopher Kruegel, Giovanni Vigna

Douglas G. Steigerwald

Fake antivirus (AV) programs have been utilized to defraud millions of computer users into paying as much as one hundred dollars for a phony software license. As a result, fake AV software has evolved into one of the most lucrative criminal operations on the Internet. In this paper, we examine the operations of three large-scale fake AV businesses, lasting from three months to more than two years. More precisely, we present the results of our analysis on a trove of data obtained from several backend servers that the cybercriminals used to drive their scam operations. Our investigations reveal that these …