Statistics and Probability Commons^™

Association Between Class Iii Obesity (Bmi Of 40-59 Kg/M2) And Mortality: A Pooled Analysis Of 20 Prospective Studies, Cari M. Kitahara, Alan J. Flint, Amy Berrington De Gonzalez, Leslie Bernstein, Michelle Brotzman, Kim Robien, +30 Additional Authors

Epidemiology Faculty Publications

Background

The prevalence of class III obesity (body mass index [BMI]≥40 kg/m2) has increased dramatically in several countries and currently affects 6% of adults in the US, with uncertain impact on the risks of illness and death. Using data from a large pooled study, we evaluated the risk of death, overall and due to a wide range of causes, and years of life expectancy lost associated with class III obesity.

Methods and Findings

In a pooled analysis of 20 prospective studies from the United States, Sweden, and Australia, we estimated sex- and age-adjusted total and cause-specific mortality rates (deaths per …

Trends And Determinants Of Up-To-Date Status With Colorectal Cancer Screening In Tennessee, 2002-2008, Sreenivas P. Veeranki, Shimin Zheng

ETSU Faculty Works

BACKGROUND:

Screening rates for colorectal cancer (CRC) are increasing nationwide including Tennessee (TN); however, their up-to-date status is unknown. The objective of this study is to determine the trends and characteristics of TN adults who are up-to-date status with CRC screening during 2002-2008.

METHODS:

We examined data from the TN Behavioral Risk Factor Surveillance System for 2002, 2004, 2006 and 2008 to estimate the proportion of respondents aged 50 years and above who were up-to-date status with CRC screening, defined as an annual home fecal occult blood test and/or sigmoidoscopy or colonoscopy in the past 5 years. We identified trends …

Rationale, Design, And Baseline Characteristics Of A Randomized, Placebo-Controlled Cardiovascular Outcome Trial Of Empagliflozin (Empa-Reg Outcometm), Bernard Zinman, Silvio E. Inzucchi, John M. Lachin, Christoph Wanner, Roberto Ferrari, David Fitchett, Erich Bluhmki, Stefan Hantel, Joan Kempthorne-Rawson, Jennifer Newman, Odd Erik Johansen, Hans Juergen Woerle, Uli C. Broedl

Epidemiology Faculty Publications

Background

Evidence concerning the importance of glucose lowering in the prevention of cardiovascular (CV) outcomes remains controversial. Given the multi-faceted pathogenesis of atherosclerosis in diabetes, it is likely that any intervention to mitigate this risk must address CV risk factors beyond glycemia alone. The SGLT-2 inhibitor empagliflozin improves glucose control, body weight and blood pressure when used as monotherapy or add-on to other antihyperglycemic agents in patients with type 2 diabetes. The aim of the ongoing EMPA-REG OUTCOMETM trial is to determine the long-term CV safety of empagliflozin, as well as investigating potential benefits on microvascular outcomes.

Methods

Patients who …

Vitamin D Status And Demographic And Lifestyle Determinants Among Adults In The United States (Nhanes 2001-2006), Yan Cao, Katie L. Callahan, Sreenivas P. Veeranki, Yang Chen, Ying Liu, Shimin Zheng

ETSU Faculty Works

This study looked at risk factors associated with vitamin D levels in the body among a representative sample of adults in the U.S., NHANES III (2001-2006) data were used to assess the relationship between several demographic and health risk factors and vitamin D levels in the body. The Baseline-Category Logit Model was used to test the association between vitamin D level and the potential risk factors age, education, ethnicity, poverty status, physical activity, smoking, alcohol, obesity, diabetes and total cholesterol with both genders. Vitamin D insufficiency and deficiency were significantly associated with age, race, education, physical activity, obesity, diabetes and …

Trend Analysis And Modeling Of Health And Environmental Data: Joinpoint And Functional Approach, Ram C. Kafle

USF Tampa Graduate Theses and Dissertations

The present study is divided into two parts: the first is on developing the statistical analysis and modeling of mortality (or incidence) trends using Bayesian joinpoint regression and the second is on fitting differential equations from time series data to derive the rate of change of carbon dioxide in the atmosphere.

Joinpoint regression model identifies significant changes in the trends of the incidence, mortality, and survival of a specific disease in a given population. Bayesian approach of joinpoint regression is widely used in modeling statistical data to identify the points in the trend where the significant changes occur. The purpose …

Gwas Identifies An Nat2 Acetylator Status Tag Single Nucleotide Polymorphism To Be A Major Locus For Skin Fluorescence, Karen M. Eny, Helen L. Lutgers, John Maynard, Barbara E.K. Klein, Kristine E. Lee, Patricia A. Cleary, +20 Additional Authors

Epidemiology Faculty Publications

Aims/hypothesis

Skin fluorescence (SF) is a non-invasive marker of AGEs and is associated with the long-term complications of diabetes. SF increases with age and is also greater among individuals with diabetes. A familial correlation of SF suggests that genetics may play a role. We therefore performed parallel genome-wide association studies of SF in two cohorts.

Methods

Cohort 1 included 1,082 participants, 35–67 years of age with type 1 diabetes. Cohort 2 included 8,721 participants without diabetes, aged 18–90 years.

Results

rs1495741 was significantly associated with SF in Cohort 1 (p < 6 × 10−10), which is known to tag theNAT2 acetylator phenotype. The fast acetylator genotype was associated …

Assessing The Impact Of Misclassification When Comparing Prevalence Data: A Novel Sensitivity Analysis Approach, Ninet Sinaii, Sean D. Cleary, Pamela Stratton

Epidemiology Faculty Publications

Background: A simple sensitivity analysis technique was developed to assess the impact of misclassification and verify observed prevalence differences between distinct populations.

Methods: The prevalence of self-reported comorbid diseases in 4,331 women with surgically-diagnosed endometriosis was compared to published clinical and population-based prevalence estimates. Disease prevalence misclassification was assessed by assuming over-reporting in the study sample and under-reporting in the general (comparison) population. Over- and under-reporting by 10%, 25%, 50%, 75%, and 90% was used to create a 5×5 table for each disease. The new prevalences represented by each table cell were compared by p-values, prevalence odds ratios, and 95% …

Socioeconomic And Demographic Factors Modify The Association Between Informal Caregiving And Health In The Sandwich Generation, Elizabeth K. Do, Steven A. Cohen, Monique J. Brown Ph.D., Mph

Faculty Publications

Background

Nearly 50 million Americans provide informal care to an older relative or friend. Many are members of the “sandwich generation”, providing care for elderly parents and children simultaneously. Although evidence suggests that the negative health consequences of caregiving are more severe for sandwiched caregivers, little is known about how these associations vary by sociodemographic factors.

Methods

We abstracted data from the Behavioral Risk Factor Surveillance System to determine how the association between caregiving and health varies by sociodemographic factors, using ordinal logistic regression with interaction terms and stratification by number of children, income, and race/ethnicity.

Results

The association between …

Venue-Based Recruitment Of Women At Elevated Risk For Hiv: An Hiv Prevention Trials Network Study, Danielle F. Haley, Carol E. Golin, Wafaa M. El-Sadr, James P. Hughes, Jing Wang, Irene Kuo, +13 Additional Authors

Epidemiology Faculty Publications

Background: The challenge of identifying and recruiting U.S. women at elevated risk for HIV acquisition impedes prevention studies and services. HIV Prevention Trials Network (HPTN) 064 was a U.S. multisite, longitudinal cohort study designed to estimate HIV incidence among women living in communities with prevalent HIV and poverty. Venue-based sampling (VBS) methodologies and participant and venue characteristics are described.

Methods: Eligible women were recruited from 10 U.S. communities with prevalent HIV and poverty using VBS. Participant eligibility criteria included age 18–44 years, residing in a designated census tract/zip code, and self-report of at least one high-risk personal and/or male sexual …

The Impact Of Salsalate Treatment On Serum Levels Of Advanced Glycation End Products In Type 2 Diabetes., Joshua I Barzilay, Kathleen A. Jablonski, Vivian Fonseca, Steven E Shoelson, Allison B Goldfine, Christopher Strauch, Vincent M Monnier, Tinsal-T2d Research Consortium.

GW Biostatistics Center

OBJECTIVE Salsalate is a nonacetylated salicylate that lowers glucose levels in people with type 2 diabetes (T2D). Here we examined whether salsalate also lowered serum-protein-bound levels of early and advanced glycation end products (AGEs) that have been implicated in diabetic vascular complications. RESEARCH DESIGN AND METHODS Participants were from the Targeting Inflammation Using Salsalate for Type 2 Diabetes (TINSAL-T2D) study, which examined the impact of salsalate treatment on hemoglobin A1c (HbA1c) and a wide variety of other parameters. One hundred eighteen participants received salsalate, 3.5 g/day for 48 weeks, and 109 received placebo. Early glycation product levels (HbA1c and fructoselysine …

Genetic Risk Of Progression To Type 2 Diabetes And Response To Intensive Lifestyle Or Metformin In Prediabetic Women With And Without A History Of Gestational Diabetes Mellitus., Shannon D Sullivan, Kathleen A. Jablonski, Jose C Florez, Dana Dabelea, Paul W Franks, Sam Dagogo-Jack, Catherine Kim, William C Knowler, Costas A Christophi, Robert Ratner, Diabetes Prevention Program Research Group.

GW Biostatistics Center

OBJECTIVE The Diabetes Prevention Program (DPP) trial investigated rates of progression to diabetes among adults with prediabetes randomized to treatment with placebo, metformin, or intensive lifestyle intervention. Among women in the DPP, diabetes risk reduction with metformin was greater in women with prior gestational diabetes mellitus (GDM) compared with women without GDM but with one or more previous live births.

RESEARCH DESIGN AND METHODS We asked if genetic variability could account for these differences by comparing β-cell function and genetic risk scores (GRS), calculated from 34 diabetes-associated loci, between women with and without histories of GDM.

RESULTS β-Cell function was …

Metabolic Syndrome Components And Their Response To Lifestyle And Metformin Interventions Are Associated With Differences In Diabetes Risk In Persons With Impaired Glucose Tolerance, H. Florez, M. Temprosa, Trevor J. Orchard, Kieren J. Mather, Santica M. Marcovina, Elizabeth Barrett-Connor, Edward Horton, C. D. Saudek, F. X. Pi-Sunyer, R. E. Ratner, R. B. Goldberg

GW Biostatistics Center

Aims

To determine the association of metabolic syndrome (MetS) and its components with diabetes risk in participants with impaired glucose tolerance (IGT), and whether intervention-related changes in MetS lead to differences in diabetes incidence.

Methods

We used the National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III) revised MetS definition at baseline and intervention-related changes of its components to predict incident diabetes using Cox models in 3234 Diabetes Prevention Program (DPP) participants with IGT over an average follow-up of 3.2 years.

Results

In an intention-to-treat analysis, the demographic-adjusted hazard ratios (95% confidence interval) for diabetes in those with MetS (vs. …

A Unification Of Mediation And Interaction: A Four-Way Decomposition, Tyler J. Vanderweele

Harvard University Biostatistics Working Paper Series

It is shown that the overall effect of an exposure on an outcome, in the presence of a mediator with which the exposure may interact, can be decomposed into four components: (i) the effect of the exposure in the absence of the mediator, (ii) the interactive effect when the mediator is left to what it would be in the absence of exposure, (iii) a mediated interaction, and (iv) a pure mediated effect. These four components, respectively, correspond to the portion of the effect that is due to neither mediation nor interaction, to just interaction (but not mediation), to both mediation …

New Malignancies After Squamous Cell Carcinoma And Melanomas: A Population-Based Study From Norway, Trude E. Robsahm, Margaret R. Karagas, Judy R. Rees, Astri Syse

Dartmouth Scholarship

Skin cancer survivors experience an increased risk for subsequent malignancies but the associated risk factors are poorly understood. This study examined the risk of a new primary cancer following an initial skin cancer and assessed risk factors associated with second primary cancers.

The Association Of Calcium Intake And Other Risk Factors With Cardiovascular Disease Among Obese Adults In Usa, Yang Chen, Sheryl Strasser, Katie Callahan, David Blackley, Yan Cao, Liang Wang, Shimin Zheng

ETSU Faculty Works

In this study, we used a cross-sectional study design to examine the relationship between the calcium intake and risk factors for CVD among obese adults by using continuous waves of National Health and Nutrition Examination Survey (NHANES) data 1999-2010. The association between calcium intake and risk factors of CVD (hypertension, total cholesterol, HDL, glycohemoglobin), CRP, albuminuria) is assessed among obese adults in USA. The incidence of Cardiovascular Disease (CVD) is high among obese people. The potential effects of inadequate calcium intake on CVD are receiving increased epidemiologic attention. Understanding the association between risk factors for CVD and calcium intake among …

Computational Model For Survey And Trend Analysis Of Patients With Endometriosis : A Decision Aid Tool For Ebm, Salvo Reina, Vito Reina, Franco Ameglio, Mauro Costa, Alessandro Fasciani

COBRA Preprint Series

Endometriosis is increasingly collecting worldwide attention due to its medical complexity and social impact. The European community has identified this as a “social disease”. A large amount of information comes from scientists, yet several aspects of this pathology and staging criteria need to be clearly defined on a suitable number of individuals. In fact, available studies on endometriosis are not easily comparable due to a lack of standardized criteria to collect patients’ informations and scarce definitions of symptoms. Currently, only retrospective surgical stadiation is used to measure pathology intensity, while the Evidence Based Medicine (EBM) requires shareable methods and correct …

Adaptive Pair-Matching In The Search Trial And Estimation Of The Intervention Effect, Laura Balzer, Maya L. Petersen, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In randomized trials, pair-matching is an intuitive design strategy to protect study validity and to potentially increase study power. In a common design, candidate units are identified, and their baseline characteristics used to create the best n/2 matched pairs. Within the resulting pairs, the intervention is randomized, and the outcomes measured at the end of follow-up. We consider this design to be adaptive, because the construction of the matched pairs depends on the baseline covariates of all candidate units. As consequence, the observed data cannot be considered as n/2 independent, identically distributed (i.i.d.) pairs of units, as current practice assumes. …

Concomitant Socioeconomic, Behavioral, And Biological Factors Associated With The Disproportionate Hiv Infection Burden Among Black Men Who Have Sex With Men In 6 U.S. Cities, Kenneth H. Mayer, Lei Wang, Beryl A. Koblin, Sharon B. Mannheimer, Manya Magnus, +13 Additional Authors

Epidemiology Faculty Publications

Background

American Black men who have sex with men (MSM) are disproportionately affected by HIV, but the factors associated with this concentrated epidemic are not fully understood.

Methods

Black MSM were enrolled in 6 US cities to evaluate a multi-component prevention intervention, with the current analysis focusing on the correlates of being newly diagnosed with HIV compared to being HIV-uninfected or previously diagnosed with HIV.

Results

HPTN 061 enrolled 1553 Black MSM whose median age was 40; 30% self-identified exclusively as gay or homosexual, 29% exclusively as bisexual, and 3% as transgender. About 1/6th(16.2%) were previously diagnosed with HIV (PD); …

Estimating Population Treatment Effects From A Survey Sub-Sample, Kara E. Rudolph, Ivan Diaz, Michael Rosenblum, Elizabeth A. Stuart

Johns Hopkins University, Dept. of Biostatistics Working Papers

We consider the problem of estimating an average treatment effect for a target population from a survey sub-sample. Our motivating example is generalizing a treatment effect estimated in a sub-sample of the National Comorbidity Survey Replication Adolescent Supplement to the population of U.S. adolescents. To address this problem, we evaluate easy-to-implement methods that account for both non-random treatment assignment and a non-random two-stage selection mechanism. We compare the performance of a Horvitz-Thompson estimator using inverse probability weighting (IPW) and two double robust estimators in a variety of scenarios. We demonstrate that the two double robust estimators generally outperform IPW in …

Analysis Of Schizophrenia Data Using A Nonlinear Threshold Index Logistic Model., Zhenyu Jiang, Chengan Du, Assen Jablensky, Hua Liang, Zudi Lu, Yang Ma, Kok Lay Teo

GW Biostatistics Center

Genetic information, such as single nucleotide polymorphism (SNP) data, has been widely recognized as useful in prediction of disease risk. However, how to model the genetic data that is often categorical in disease class prediction is complex and challenging. In this paper, we propose a novel class of nonlinear threshold index logistic models to deal with the complex, nonlinear effects of categorical/discrete SNP covariates for Schizophrenia class prediction. A maximum likelihood methodology is suggested to estimate the unknown parameters in the models. Simulation studies demonstrate that the proposed methodology works viably well for moderate-size samples. The suggested approach is therefore …

Mediation Analysis Of Gestational Age, Congenital Heart Defects, And Infant Birth-Weight, Adane Wogu, Christopher Loffredo, Ionut Bebu, George Luta

GW Biostatistics Center

Background

In this study we assessed the mediation role of the gestational age on the effect of the infant’s congenital heart defects (CHD) on birth-weight.

Methods

We used secondary data from the Baltimore-Washington Infant Study (1981–1989). Mediation analysis was employed to investigate whether gestational age acted as a mediator of the association between CHD and reduced birth-weight. We estimated the mediated effect, the mediation proportion, and their corresponding 95% confidence intervals (CI) using several methods.

Results

There were 3362 CHD cases and 3564 controls in the dataset with mean birth-weight of 3071 (SD = 729) and 3353 (SD = 603) …

Engagement With Care, Substance Use, And Adherence To Therapy In Hiv/Aids, Patrice K. Nicholas, Suzanne Willard, Clinton J. Thompson, Carol Dawson-Rose, Inge B. Corless, +20 Additional Authors

GW Biostatistics Center

Engagement with care for those living with HIV is aimed at establishing a strong relationship between patients and their health care provider and is often associated with greater adherence to therapy and treatment (Flickinger, Saha, Moore, and Beach, 2013). Substance use behaviors are linked with lower rates of engagement with care and medication adherence (Horvath, Carrico, Simoni, Boyer, Amico, and Petroli, 2013). This study is a secondary data analysis using a cross-sectional design from a larger randomized controlled trial (n = 775) that investigated the efficacy of a self-care symptom management manual for participants living with HIV. Participants were …

Short And Long-Term Lifestyle Coaching Approaches Used To Address Diverse Participant Barriers To Weight Loss And Physical Activity Adherence, Elizabeth M. Venditti, Judith Wylie-Rosett, Linda M. Delahanty, Lisa L. Mele, Mary A. Hoskin, Sharon Edelstein

GW Biostatistics Center

Background

Individual barriers to weight loss and physical activity goals in the Diabetes Prevention Program, a randomized trial with 3.2 years average treatment duration, have not been previously reported. Evaluating barriers and the lifestyle coaching approaches used to improve adherence in a large, diverse participant cohort can inform dissemination efforts.

Methods

Lifestyle coaches documented barriers and approaches after each session (mean session attendance = 50.3 +/- 21.8). Subjects were 1076 intensive lifestyle participants (mean age = 50.6 years; mean BMI = 33.9 kg/m2; 68% female, 48% non-Caucasian). Barriers and approaches used to improve adherence were ranked by the percentage of …

Cardiometabolic Risk Assessments By Body Mass Index Z-Score Or Waist-To-Height Ratio In A Multiethnic Sample Of Sixth-Graders, Henry S. Kahn, Laure El Ghormli, Russell Jago, Gary D. Foster, Robert G. Mcmurray, John B. Buse, Diane D. Stadler, Roberto P. Trevino, Tom Baranowski, Healthy Study Group

GW Biostatistics Center

Convention defines pediatric adiposity by the body mass index -score (BMIz) referenced to normative growth charts. Waist-to-height ratio (WHtR) does not depend on sex-and-age references. In the HEALTHY Study enrollment sample, we compared BMIz with WHtR for ability to identify adverse cardiometabolic risk. Among 5,482 sixth-grade students from 42 middle schools, we estimated explanatory variations (R²) and standardized beta coefficients of BMIz or WHtR for cardiometabolic risk factors: insulin resistance (HOMA-IR), lipids, blood pressures, and glucose. For each risk outcome variable, we prepared adjusted regression models for four subpopulations stratified by sex and high versus lower fatness. …

Community Colleges And Public Health: An Integral Part Of The Continuum Of Education For Public Health, Richard Riegelman, Cynthia Wilson

Epidemiology Faculty Publications

No abstract provided.

Hiv Testing Implementation In Two Urban Cities: Practice, Policy, And Perceived Barriers., Camden J Hallmark, Jennifer Skillicorn, Thomas P Giordano, Jessica A Davila, Marlene Mcneese, Nestor Rocha, Avemaria Smith, Stacey Cooper, Amanda D. Castel

Epidemiology Faculty Publications

BACKGROUND: Although funding has supported the scale up of routine, opt-out HIV testing in the US, variance in implementation mechanisms and barriers in high-burden jurisdictions remains unknown.

METHODS: We conducted a survey of health care organizations in Washington, DC and Houston/Harris County to determine number of HIV tests completed in 2011, policy and practices associated with HIV testing, funding mechanisms, and reported barriers to testing in each jurisdiction and to compare results between jurisdictions.

RESULTS: In 2012, 43 Houston and 35 DC HIV-testing organizations participated in the survey. Participants represented 85% of Department of Health-supported testers in DC and 90% …

Primary Care-Based Educational Interventions To Decrease Risk Factors For Metabolic Syndrome For Adults With Major Psychotic And/Or Affective Disorders: A Systematic Review, Cynthia Nover, Sarah S. Jackson

Epidemiology Faculty Publications

Background

Individuals with major psychotic and/or affective disorders are at increased risk for developing metabolic syndrome due to lifestyle- and treatment-related factors. Numerous pharmacological and non-pharmacological interventions have been tested in inpatient and outpatient mental health settings to decrease these risk factors. This review focuses on primary care-based non-pharmacological (educational or behavioral) interventions to decrease metabolic syndrome risk factors in adults with major psychotic and/or affective disorders.

Methods

The authors conducted database searches of PsychINFO, MEDLINE and the Cochrane Database of Systematic Reviews, as well as manual searches and gray literature searches to identify included studies.

Results

The authors were …

Multiple Hypotheses Testing Procedures In Clinical Trials And Genomic Studies, Qing Pan

Epidemiology Faculty Publications

We review and compare multiple hypothesis testing procedures used in clinical trials and those in genomic studies. Clinical trials often employ global tests, which draw an overall conclusion for all the hypotheses, such as SUM test, Two-Step test, Approximate Likelihood Ratio test (ALRT), Intersection-Union Test (IUT), and MAX test. The SUM and Two-Step tests are most powerful under homogeneous treatment effects, while the ALRT and MAX test are robust in cases with non-homogeneous treatment effects. Furthermore, the ALRT is robust to unequal sample sizes in testing different hypotheses. In genomic studies, stepwise procedures are used to draw marker-specific conclusions and …

Targeting Inflammation Using Salsalate In Patients With Type 2 Diabetes: Effects On Flow-Mediated Dilation (Tinsal-Fmd)., Allison B Goldfine, J Stewart Buck, Cyrus Desouza, Vivian Fonseca, Yii-Der Ida Chen, Steven E Shoelson, Kathleen A. Jablonski, Mark A Creager, The Tinsal-Fmd Team

GW Biostatistics Center

OBJECTIVE: To test whether inhibiting inflammation with salsalate improves endothelial function in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS: We conducted an ancillary study to the National Institutes of Health-sponsored, multicenter, randomized, double-masked, placebo-controlled trial evaluating the safety and efficacy of salsalate in targeting inflammation to improve glycemia in patients with T2D. Flow-mediated, endothelium-dependent dilation (FMD) and endothelium-independent, nitroglycerin-mediated dilation (NMD) of the brachial artery were assessed at baseline and 3 and 6 months following randomization to either salsalate 3.5 g/day or placebo. The primary end point was change in FMD at 6 months.

RESULTS: A total …

Factors Associated With Parental Decision Making And Childhood Vaccination, Zuwen Qiu-Shultz

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to better understand factors affecting immunization status, logistic regression was used to assess the association of various socio-demographic factors and whether parents would have their child immunized if not a state mandate. Factors included in the study were race, household income, number of children in the household, number of adults in the household, if the child had a primary provider, if the child had a health check-up in the last twelve months, and medical insurance status of the child. The combined Nevada Kindergarten Health Survey Result of 2009-2010 (Year Two) and 2010-2011 (Year Three) conducted by the Nevada …