Epidemiology Commons^™

Glycemic Index, Glycemic Load, And Pancreatic Cancer Risk (Canada), Stephanie A. Navarro Silvera, Thomas E. Rohan, Meera Jain, Paul D. Terry, Geoffrey R. Howe, Anthony B. Miller

Department of Public Health Scholarship and Creative Works

There is some evidence that plasma insulin and post-load plasma glucose may be associated with the risk of pancreatic cancer. Glycemic index and glycemic load are measures, which allow the carbohydrate content of individual foods to be classified according to their postprandial glycemic effects and hence their effects on circulating insulin levels. Therefore, we examined pancreatic cancer risk in association with a glycemic index (GI), glycemic load (GL), and intake of dietary carbohydrate and sugar in a prospective cohort of 49,613 Canadian women enrolled in the National Breast Screening Study (NBSS) who completed a self-administered food frequency questionnaire between 1980 …

Scale Development For Perceived School Climate For Girls’ Physical Activity, Amanda Birnbaum, Kelly R. Evenson, Robert W. Motl, Rod K. Dishman, Carolyn C. Voorhees, James F. Sallis, John P. Elder, Marsha Dowda

Department of Public Health Scholarship and Creative Works

Objectives: To test an original scale assessing perceived school climate for girls' physical activity in middle school girls. Methods: Confirmatory factor analysis (CFA) and structural equation modeling (SEM). Results: CFA retained 5 of 14 original items. A model with 2 correlated factors, perceptions about teachers' and boys' behaviors, respectively, fit the data well in both sixth and eighth-graders. SEM detected a positive, significant direct association of the teacher factor, but not the boy factor, with girls' self-reported physical activity. Conclusions:School climate for girls' physical activity is a measurable construct, and preliminary evidence suggests a relationship with physical activity.

Causal Inference In Longitudinal Studies With History-Restricted Marginal Structural Models, Romain Neugebauer, Mark J. Van Der Laan, Ira B. Tager

U.C. Berkeley Division of Biostatistics Working Paper Series

Causal Inference based on Marginal Structural Models (MSMs) is particularly attractive to subject-matter investigators because MSM parameters provide explicit representations of causal effects. We introduce History-Restricted Marginal Structural Models (HRMSMs) for longitudinal data for the purpose of defining causal parameters which may often be better suited for Public Health research. This new class of MSMs allows investigators to analyze the causal effect of a treatment on an outcome based on a fixed, shorter and user-specified history of exposure compared to MSMs. By default, the latter represents the treatment causal effect of interest based on a treatment history defined by the …

Cardiorespiratory Hospitalizations Associated With Smoke Exposure During The 1997, Southeast Asian Forest Fires, Joshua A. Mott, David M. Mannino, Clinton J. Alverson, Andrew Kiyu, Jamilah Hashim, Tzesan Lee, Kenneth Falter, Stephen C. Redd

David M. Mannino

We investigated the cardiorespiratory health effects of smoke exposure from the 1997 Southeast Asian Forest Fires among persons who were hospitalized in the region of Kuching, Malaysia. We selected admissions to seven hospitals in the Kuching region from a database of all hospital admissions in the state of Sarawak during January 1, 1995 and December 31, 1998. For several cardiorespiratory disease classifications we used Holt-Winters time-series analyses to determine whether the total number of monthly hospitalizations during the forest fire period (August 1 to October 31, 1997), or post-fire period (November 1, 1997 to December 31, 1997) exceeded forecasted estimates …

History-Adjusted Marginal Structural Models: Time-Varying Effect Modification, Maya L. Petersen, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Marginal structural models (MSM) provide a powerful tool for estimating the causal effect of a treatment, particularly in the context of longitudinal data structures. These models, introduced by Robins, model the marginal distributions of treatment-specific counterfactual outcomes, possibly conditional on a subset of the baseline covariates. However, standard MSM cannot incorporate modification of treatment effects by time-varying covariates. In the context of clinical decision- making such time-varying effect modifiers are often of considerable interest, as they are used in practice to guide treatment decisions for an individual. In this article we introduce a generalization of marginal structural models, which we …

History-Adjusted Marginal Structural Models: Optimal Treatment Strategies, Maya L. Petersen, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Much of clinical medicine involves choosing a future treatment plan that is expected to optimize a patient's long-term outcome, and modifying this treatment plan over time in response to changes in patient characteristics. However, dynamic treatment regimens, or decision rules for altering treatment in response to time-varying covariates, are rarely estimated based on observational data. In a companion paper, we introduced a generalization of Marginal Structural Models, named History-Adjusted Marginal Structural Models, that estimate modification of causal effects by time-varying covariates. Here, we illustrate how History-Adjusted Marginal Structural Models can be used to identify a specific type of optimal dynamic …

Predictors Of Violent Behavior In An Early Adolescent Cohort: Similarities And Differences Across Genders, Jonathan L. Blitstein, David M. Murray, Leslie A. Lytle, Amanda Birnbaum, Cheryl L. Perry

Department of Public Health Scholarship and Creative Works

The authors assessed a cohort of 2,335 students from the Minneapolis, Minnesota, area to identify predictors of violent behavior and to determine whether the predictors varied by gender. The sample was 76% White; boys and girls were equally represented. The majority lived with two parents. A measure of violent behavior collected at the end of the eighth-grade year (2000) was entered into Poisson regression against baseline data collected at the beginning of the seventh-grade year (1998). Predictors of violent behavior influencing both boys and girls included depressive symptoms, perceived invulnerability to negative future events, paternal nonauthoritative behavior, and drinking alcohol. …

The Role Of Peer Social Network Factors And Physical Activity In Adolescent Girls, Carolyn C. Voorhees, David Murray, Greg Welk, Amanda Birnbaum, Kurt M. Ribisi, Carolyn C. Johnson, Karin Allor Pfeiffer, Brit Saksvig, Jared B. Jobe

Department of Public Health Scholarship and Creative Works

Objective: To study the relationship between peer-related physical activity (PA) social networks and the PA of adolescent girls.

Methods: Cross-sectional, convenience sample of adolescent girls. Mixed-model linear regression analyses to identify significant correlates of self-reported PA while accounting for correlation of girls in the same school.

Results: Younger girls were more active than older girls. Most activity-related peer social network items were related to PA levels. More PA with friends was significantly related to self-reported PA in multivariate analyses.

Conclusions: Frequency of PA with friends was an important correlate of PA among the peer network variables …

Using Media Messaging To Promote Healthful Eating And Physical Activity Among Urban Youth, B.J. Carter, Amanda Birnbaum, Lisa Hark, Brian Vickery, Charles Potter, Michael P. Osborne

Department of Public Health Scholarship and Creative Works

National trends show consistent increases, as well as racial and ethnic dis- parities, in the prevalence of overweight children and adolescents. Such disparity is evident regarding behaviors such as a poor diet and a lack of physical activity and in the prevalence and outcomes of associated health problems. It has been suggested that grounding interventions in cultural traditions and norms are critical for preventing obesity among ethnic and racial minority youth; however, with some notable exceptions, few community interventions have used this approach. Moreover, urban minority youth may face additional barriers to healthful eating and physical activity behaviors, such as …

Using Media Messaging To Promote Healthful Eating And Physical Activity Among Urban Youth, B.J Carter, Amanda Birnbaum, Lisa Hark, Brian Vickery, Charles Potter, Michael P. Osborne

Department of Public Health Scholarship and Creative Works

National trends show consistent increases, as well as racial and ethnic dis- parities, in the prevalence of overweight children and adolescents. Such disparity is evident regarding behaviors such as a poor diet and a lack of physical activity and in the prevalence and outcomes of associated health problems. It has been suggested that grounding interventions in cultural traditions and norms are critical for preventing obesity among ethnic and racial minority youth; however, with some notable exceptions, few community interventions have used this approach. Moreover, urban minority youth may face additional barriers to healthful eating and physical activity behaviors, such as …

Patient Characteristics And Clinical Management Of Patients With Shoulder Pain In U.S. Primary Care Settings: Secondary Data Analysis Of The National Ambulatory Medical Care Survey, James L. Wofford, Richard J. Mansfield, Raquel S. Watkins

Dartmouth Scholarship

Although shoulder pain is a commonly encountered problem in primary care, there are few studies examining its presenting characteristics and clinical management in this setting. We performed secondary data analysis of 692 office visits for shoulder pain collected through the National Ambulatory Medical Care Survey (Survey years 1993–2000). Information on demographic characteristics, history and place of injury, and clinical management (physician order of imaging, physiotherapy, and steroid intraarticular injection) were examined.

Longitudinal Invariance Of The Center For Epidemiologic Studies-Depression Scale Among Girls And Boys In Middle School, Robert W. Motl, Rod K. Dishman, Amanda Birnbaum, Leslie A. Lytle

Department of Public Health Scholarship and Creative Works

This study tested the longitudinal factorial invariance of a theoretically consistent, higher-order model for Center for Epidemiologic Studies-Depression (CES-D) scores among adolescent girls and boys in middle school. Data were collected from 2,416 adolescents who completed a survey containing the CES-D in the fall of 1998, spring of 1999, and spring of 2000. The invariance analyses were conducted using LISREL 8.50 with maximum likelihood estimation and the Satorra-Bentler scaled chi-square statistic and standard errors. The higher-order model demonstrated longitudinal, as well as gender, invariance of the overall factor structure and first- and second-order structure coefficients, first-order factor variances, second-order factor …

Insights Into Latent Class Analysis, Margaret S. Pepe, Holly Janes

UW Biostatistics Working Paper Series

Latent class analysis is a popular statistical technique for estimating disease prevalence and test sensitivity and specificity. It is used when a gold standard assessment of disease is not available but results of multiple imperfect tests are. We derive analytic expressions for the parameter estimates in terms of the raw data, under the conditional independence assumption. These expressions indicate explicitly how observed two- and three-way associations between test results are used to infer disease prevalence and test operating characteristics. Although reasonable if the conditional independence model holds, the estimators have no basis when it fails. We therefore caution against using …

Standardizing Markers To Evaluate And Compare Their Performances, Margaret S. Pepe, Gary M. Longton

UW Biostatistics Working Paper Series

Introduction: Markers that purport to distinguish subjects with a condition from those without a condition must be evaluated rigorously for their classification accuracy. A single approach to statistically evaluating and comparing markers is not yet established.

Methods: We suggest a standardization that uses the marker distribution in unaffected subjects as a reference. For an affected subject with marker value Y, the standardized placement value is the proportion of unaffected subjects with marker values that exceed Y.

Results: We apply the standardization to two illustrative datasets. In patients with pancreatic cancer placement values calculated for the CA 19-9 marker are smaller …

Combining Predictors For Classification Using The Area Under The Roc Curve, Margaret S. Pepe, Tianxi Cai, Zheng Zhang, Gary M. Longton

UW Biostatistics Working Paper Series

No single biomarker for cancer is considered adequately sensitive and specific for cancer screening. It is expected that the results of multiple markers will need to be combined in order to yield adequately accurate classification. Typically the objective function that is optimized for combining markers is the likelihood function. In this paper we consider an alternative objective function -- the area under the empirical receiver operating characteristic curve (AUC). We note that it yields consistent estimates of parameters in a generalized linear model for the risk score but does not require specifying the link function. Like logistic regression it yields …

Impact Of The Introduction Of Pneumococcal Conjugate Vaccine On Immunization Coverage Among Infants, Nancy D. Lin, Ken Kleinman, K Arnold Chan, Xian-Jie Yu, Eric K. France, Stanley Xu, Feifei Wei, John Mullooly, Jeanne Santoli, Tracey A. Lieu, Vaccine Safety Datalink Group

Public Health Department Faculty Publication Series

Background

The introduction of pneumococcal conjugate vaccine (PCV) to the U.S. recommended childhood immunization schedule in the year 2000 added three injections to the number of vaccinations a child is expected to receive during the first year of life. Surveys have suggested that the addition of PCV has led some immunization providers to move other routine childhood vaccinations to later ages, which could increase the possibility of missing these vaccines. The purpose of this study was to evaluate whether introduction of PCV affected immunization coverage for recommended childhood vaccinations among 13-month olds in four large provider groups.

Methods

In this …

Extended Vs. Small Field Irradiation In High Risk Post Esophagectomy Patients Receiving Combined Chemoradiation Therapy: A Decade Experience In Treatment Of Esophageal Cancer, Edward Yu, Patricia Tai, George Rodrigues, Robert Ash, Larry Stitt, Rashid A. Dar, Pauline Truong, Gregory M. Videtic, Richard Malthaner, Richard Inculet, Anna Tomiak, Jawaid Younus, Brian Dingle, Walter Kocha, Mark Vincent

Oncology Presentations

OBJECTIVE: To assess the impact of extended field irradiation with anastomotic coverage on local recurrence in high risk resected esophageal cancerpatients.

METHODS: From 1989-1999, high risk resected esophageal cancer cases receiving post-resection chemoradiation were reviewed. Adjuvant chemotherapy consisted of four cycles of fluorouracil-based regimens. Loco-regional irradiation with or without coverage of anastomotic site had radiation a dose range from 45-60 Gyat 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage), or small (without anastomotic coverage) field followed by oblique fields for boost.

RESULTS: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation. …

Higher Burden Of Hemorrhagic Stroke Among Women An Autopsy-Based Study In São Paulo, Brazil, Paulo A. Lotufo

Paulo A Lotufo

The aim of this study was to verify the gender difference in sudden cardiovascular death, mainly comparing brain infarction and hemorrhagic stroke. We analyzed 970 autopsy cases from a total of 3,802 nonviolent deaths (448 considered as sudden deaths, 296 undetermined, and 226 non-sudden deaths) including patients aged 30–69 years. All cardiovascular diseases were responsible for 69% of sudden deaths, and all types of stroke for only 14%. The proportions of sudden death for all cardiovascular diseases, coronary heart disease and ischemic stroke deaths were similar for both sexes. However, sudden deaths due to all types of stroke (women 20.0%; …

Stroke In Brazil: A Neglected Disease, Paulo A. Lotufo

Paulo A Lotufo

The turning point in the transition from infectious diseases to non-transmittable diseases in Brazil occurred in the 1960s, taking the country as a whole. However, considering the main cities, such as São Paulo and Rio de Janeiro, cerebrovascular disease mortality rates have surpassed the “old cardiovascular diseases” like rheumatic heart disease and syphilitic aortic disease since the end of World War II. Until the end of the 1980s, the burden of stroke mortality observed in the main Brazilian cities was higher than in the United States, Canada and western European countries, and similar to what is observed in Eastern Europe …

Trends Of Stroke Subtypes Mortality In Sao Paulo, Brazil (1996-2003), Paulo A. Lotufo, Isabela M. Bensenor

Paulo A Lotufo

The decline of stroke mortality rates has been described in Brazil; however, there is no data about stroke subtypes. We described the changes of stroke mortality rates in the city of Sao Paulo (1996-2003) emphasizing intracerebral hemorrhage and cerebral infarction. We categorized mortality data by gender and 10-year age-strata from 30 to 79 years-old. For men, an annual reduction of all types of stroke (-3.9%), and of stroke subtypes as intracerebral hemorrhage (-3.0%) and cerebral infarction was observ e d (-2.7%) as well as, a decline of ill-defined stroke (-7.4%). For women, a decline was observed for all types of …

Why Brazil Does Not Have An Epidemic Of Chronic Diseases: Some Answers From Cardiovascular Diseases, Paulo A. Lotufo

Paulo A Lotufo

No abstract provided.

The "Common Soil" Theory: Coronary Disease, Diabetes And Inflammation., Paulo A. Lotufo

Paulo A Lotufo

No abstract provided.

Progress Testing: Evaluation Of Four Years Of Application In The School Of Medicine, University Of São Paulo, Paulo A. Lotufo

Paulo A Lotufo

Progress testing is a longitudinal tool for evaluating knowledge gains during the medical school years. Objectives: (1) To implement progress testing as a form of routine evaluation; (2) to verify whether cognitive gain is a continuous variable or not; and (3) to evaluate whether there is loss of knowledge relating to basic sciences in the final years of medical school. Methods: A progress test was applied twice a year to all students from 2001 to 2004. The mean percentage score was calculated for each school year, employing ANOVA with post hoc Bonferroni test evaluation for each test. Results:Progress testing was …

A Pilot Randomized, Controlled Trial Of An In-Home Drinking Water Intervention Among Hiv + Persons, John M. Colford, Sona R. Saha, Timothy J. Wade, Catherine C. Wright, Mai Vu, Sandra Charles, Peter Jensen, Alan Hubbard, Deborah A. Levy, Joseph N. S. Eisenberg

Journal Articles: Epidemiology

Although immunocompromised persons may be at increased risk for gastrointestinal illnesses, no trials investigating drinking water treatment and gastrointestinal illness in such patients have been published. Earlier results from San Francisco suggested an association (OR 6.76) between tap water and cryptosporidiosis among HIV + persons. The authors conducted a randomized, triple-blinded intervention trial of home water treatment in San Francisco, California, from April 2000 to May 2001. Fifty HIV-positive patients were randomized to externally identical active (N = 24) or sham (N = 26) treatment devices. The active device contained a filter and UV light; the sham provided no treatment. …

The Association Between Eating Habits And Hypertension Among African American Women Compared To Other Women, Anike N. Clark

Theses and Dissertations

Background: Hypertension is a major public health concern for African American women. Many studies have shown a greater prevalence of hypertension, as well as physical inactivity, excess weight, and diabetes, in African Americans. Objective: To determine if differences in eating patterns, as measured by Healthy Eating Index (HEI) scores, between African American women and other women in the United States are associated with hypertension. Methods: Data were extracted from the Third National Health and Nutrition Examination Survey (NHANESIII). The sample included 31,189,534 women aged 45 years or greater after survey weights were applied. The majority was White (86.1 %); minority …

Predictors Of Sun Protection Practices Among Adult Women In The United States, Anne Ridgely Minter

Theses and Dissertations

Background. Skin cancer is the most common form of cancer in the United States. The main modifiable risk factor for skin cancer is exposure to excessive sun and UV radiation. More than 90% of all skin cancers are known to be caused by sun exposure. However, studies on excessive sun and UV exposure are limited. The purpose of this study was to examine risk and protective factors affecting sun protection behaviors of adult women in the United States. Methods. Data on U.S. adult women (n=17,425) from the 2003 National Health Information Survey (NHIS) was analyzed. Sun protection behaviors were assessed …

Trends In Canine Lyme Disease On The Eastern Shore Of Virginia, 2000-2005, Ellen Garrett Hillyer

Theses and Dissertations

Introduction: Lyme disease is caused by the tick-borne spirochete Borrelia burgdorferi. Research has shown that dogs can be used as sentinels for human infection of Lyme disease. The purpose of this 5-year, retrospective study was to determine if there was any evidence that the incidence of canine Lyme disease has increased between 2000 and 2005 in Accomack and Northampton counties. An increased incidence in Lyme disease in dogs may indicate an increased present or future risk of Lyme disease in humans.Methods: Cases of canine Lyme disease were identified via practice invoicing systems and dogs that received doxycycline were entered into …

Active And Passive Smoking And Blood Lead Levels In U.S. Adults: Data From The Third National Health And Nutrition Examination Survey, David M. Mannino, David M. Homa, Thomas Matte, Mauricio Hernandez-Avila

David M. Mannino

Lead is a component of tobacco and tobacco smoke. We examined the relationship between current, former, and passive smoking and blood lead levels in a nationally representative sample of 16,458 U.S. adults, aged 17 years or older, who participated in the Third National Health and Nutrition Examination Survey (1988–1994). We used linear and logistic regression modeling, adjusting for known covariates, to determine the relationship between smoking and blood lead levels. Geometric mean blood lead levels were 1.8 μg/dl, 2.1 μg/dl, and 2.3 μg/dl in never-smokers with no, low, and high cotinine levels, respectively. Levels were 2.9 μg/dl in former smokers …

The Global Distribution Of Disease And Death, Jeffrey Colman Salloway

The University Dialogue

No abstract provided.

Assessing The Relationship Between Socioeconomic Variables And Risk Of Overweight Among Children 6 Years Of Age, Marilyn Cochon Batan

Theses and Dissertations

Background: The percentage of overweight children has tripled in the last thirty years. Inconsistent findings are published regarding the relationship between socioeconomic variables and being overweight in childhood.Objective: To determine whether socioeconomic variables are associated with risk of being overweight among six year olds. Methods: Six year olds with BMI data were selected from the National Survey of Children's Health (n=4,362). Variables were coded and a low socioeconomic index was created. Using population weights, descriptive statistics were generated and regression was utilized to assess the relationship between socioeconomic variables and being 'at risk' for overweight. Socioeconomic variables were also compared …