Epidemiology & Biostatistics Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/7129

Browse

Now showing 1 - 20 of 74

Acculturation and BMI among Chinese, Korean and Vietnamese Adults in Maryland
(2011) Chen, Lu; Lee, Sunmin; Carter-Pokras, Olivia D; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Objective: To examine the relationship between acculturation and BMI among Asian Americans. Methods: Data of 847 Chinese, Korean and Vietnamese recruited for a health education program in Maryland were included. Acculturation was measured by the short version of Suinn-Lew Asian Self-Identity Acculturation Scale (SL-ASIA) and its individual components. Height and weight were measured by trained staff. Multiple linear regression was used to estimate the parameters of acculturation variables. Results: After adjusting for confounders, SL-ASIA (β=0.71, 95% CI: 0.15, 1.26), having education in the U.S (β=0.56, 95% CI: 0.01, 1.11), younger age of arrival (0-5 years: β=3.32, 95% CI: 1.84, 4.80, 6-10 years: β=1.55, 95% CI: 0.02, 3.07) and equal preference of Asian/American food in restaurants (β=0.92, 95% CI 0.38, 1.46) were associated with BMI. The association between acculturation and BMI was stronger among men than women, and weakest among Vietnamese. Conclusion: Acculturation is moderately associated with BMI among Asian Americans.
Analysis of Factors Associated With Tuberculosis Outcomes in District Kullu, India
(2012) Stone, Heather; Lee, Sunmin; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
India is the country with the largest number of tuberculosis (TB) cases, contributing 20% of the global burden of infection (1) and 2 million cases annually (2). However, few if any studies have examined the epidemiology of TB in the Northern state of Himachal Pradesh. This study is a retrospective review of medical records of all tuberculosis patients (N=1086) seen at the two hospitals in Manali, District Kullu, Himachal Pradesh, India between 2008-2011. The analysis determined that being younger, female, living in a town, and/or a patient at Mission Hospital, were factors significantly associated with having extrapulmonary versus pulmonary tuberculosis (EPTB). Being older was associated with an increased likelihood of previous/complex treatment compared to new patients. Being female, from a town, and/or older were associated with receiving a non-standard regimen. Finally, patients who were previously treated/complex were significantly more likely to receive a non-standard regimen than new patients.
APPLIED EPIDEMIOLOGICAL STUDIES OF HIGH RISK HUMAN PAPILLOMAVIRUS INFECTIONS AND RISK OF CERVICAL PRECANCER
(2017) Demarco, Maria Teresa; Carter-Pokras, Olivia; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Persistent infection with human papillomavirus (HPV) is a leading cause of cancer among women worldwide. Health care providers face a growing number of competing cervical cancer screening approaches and tests. HPV testing is very sensitive but a secondary test is needed to identify infections with sufficient risk of cervical precancer/cancer. This dissertation aims to address three questions in the management of HPV infections: (1) to compare the first HPV screening test seeking FDA approval that identifies many individual HPV types (BD Onclarity™) to two FDA approved assays (Roche cobas™ and Qiagen HC2™); (2) to clarify how HPV type influences cumulative risk of clearance, progression or persistence of HPV infections; and (3) to assess whether established etiologic co-factors for cervical precancer, given HPV infection, represent clinically useful, actionable factors that clinicians “need to know” when considering how to manage the HPV infected woman. All manuscripts in this dissertation used data from the HPV Persistence and Progression Cohort, conducted by Kaiser Permanente Northern California and the National Cancer Institute. The study population is a group of 33,295 women, ages 30 or older, who are HPV positive at baseline and have results for cytology. Contingency table methods, Kappa statistics and McNemar’s test were used to assess agreement between HPV DNA tests (manuscript 1). Competing risk proportional hazards models were used to estimate eight-year cumulative risks of HPV clearance, progression to precancer, or persistence (manuscript 2). Absolute risks from Logistic-Cox models were used to study whether co-factors acted as clinically relevant risk stratifiers (manuscript 3). Results from this dissertation suggest that: (1) Onclarity agreement was good to excellent compared with cobas and HC2, and clinical accuracy was high for detection of precancer; (2) cumulative risk of clearance varied little by HPV type, cumulative risk of progression was substantially higher for HPV16, and long-term persistence was uncommon; and (3) the most important predictors of progression from HPV infection to precancer were HPV type and cytologic result. By clarifying these aspects of methods, and management of HPV-positive women, it is hoped that this dissertation will contribute to the improvement of cervical cancer screening incorporating HPV testing.
Association between Allostatic Load and Arthritis in NHANES Adults
(2010) Scully, Lynn; Lee, Sunmin; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Objective: To examine the cross-sectional association between allostatic load and arthritis using data from the National Health and Nutrition Examination Survey (NHANES). Methods: Complete data on 7,714 adults were included in the analysis. An allostatic load (AL) index, comprising of multiple regulatory systems, was calculated from 11 biomarkers. Multivariate logistic regression was used to estimate the odds ratio (OR) for the association between allostatic load and arthritis, while accounting for confounders. Results: Significant positive associations were found between both continuous allostatic load (OR=1.12, 95% CI= 1.08-1.17) and the two highest quartile categories of AL and arthritis compared to the lowest quartile (quartile 3: OR=1.73, 95% CI=1.38-2.17, quartile 4: OR=1.79, 95% CI=1.41-2.26), after adjusting for confounders. The subscales of the inflammatory (OR=1.27, 95% CI=1.15-1.40) and metabolic system (OR=1.20, 95% CI=1.13-1.28) were also significant predictors. Conclusions: Cumulative biological risk is a plausible mechanism that is associated with arthritis.
Association Between C-Reactive Protein and Serum 25-Hydroxyvitamin D: A Negative Acute Phase Reactant
(2015) Verdin, Kelly; Lee, Sunmin; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Objective: The aims of this study were to determine whether serum 25-hydroxyvitamin-D (25-OH-vitamin D) is a negative acute phase reactant and whether class of diagnosis modifies the association between C-Reactive Protein (CRP) and 25-OH-vitamin D. Methods: Multiple linear regression analysis was utilized to assess the association between CRP and 25-OH-vitamin D in 1,043 patients with acute and chronic diseases and normal volunteers. Results: After adjusting for confounding factors, the association between CRP and 25-OH-vitamin D was statistically significant. Class of diagnosis did not modify this association. Conclusions: 25-OH-vitamin D is demonstrated to be a negative acute phase reactant in this group of patients; Therefore, it is not an accurate marker of vitamin D status in the setting of inflammation. These findings support that 25-OH-vitamin D should be interpreted cautiously when CRP is elevated and that evaluating 25-OH-vitamin D in the context of CRP will improve accuracy of 25-OH-vitamin D interpretation.
The Association between Cultural Views of Cancer and Colorectal Cancer Screening Behavior among Asian Americans in the Washington, D.C. Metropolitan Area
(2013) Jung, Mary; Lee, Sunmin; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Objective: To evaluate the association between Asian cultural views of cancer and colorectal cancer screening behavior among Asian Americans in the Washington, D.C. metropolitan area. Methods: A cross-sectional examination was conducted of 858 Chinese, Korean, and Vietnamese adults. Logistic regression was used to investigate the relationship between Asian cultural views (using 16-items from a previously developed scale) and colorectal cancer screening (self-reported yes/no). Results: When examining 10-point increases in continuous cultural views scores, a 12% (OR=0.88; 95% CI:0.82-0.97) and 7% (OR=0.93; 95% CI:0.87-1.00) decreased likelihood that an individual received screening were observed for herb use and self-care scores respectively. When examining categorical cultural views scores (Asian, Neutral, and Western), herb use and self-care were significantly associated with screening and showed a gradient effect after adjusting for age. Conclusion: Findings suggest that culturally appropriate interventions that address specific cultural views of cancer can potentially increase colorectal cancer screening among Asian Americans.
THE ASSOCIATION BETWEEN SUBMICROSCOPIC MALARIA INFECTION AND FEVER: FINDINGS FROM A CROSS-SECTIONAL STUDY IN MALAWI
(2019) Barrall, Angelica Lynne; Dyer, Typhanye V; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Individuals with submicroscopic malaria infection are an important reservoir for transmission, but the clinical consequences of these low-density parasitemia infections are poorly understood. Using cross-sectional data from six household-based surveys conducted during the dry and rainy seasons in Malawi from 2012 to 2014, this study examined the association between submicroscopic infection and fever in children and adults. For each survey, 900 households were recruited from three distinct ecological settings in southern Malawi to participate in the study (N=22,145). Overall prevalence of submicroscopic infection in the analytic sample was 8.1%. In a generalized linear mixed model accounting for clustering at the household and neighborhood levels and controlling for age and survey number, submicroscopic infection predicted fever in the dry season only (OR=1.66; 95% CI: 1.04, 2.66). Therefore, fever might not be a consistent marker of submicroscopic infection, but identification and treatment of low parasitemia infections is necessary to eliminate malaria transmission.
Association of Life Events with Depressive Symptoms among Puerto Rican Youth
(2014) Jaschek, Graciela; Carter-Pokras, Olivia D.; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
BACKGROUND: Early onset depressive symptoms have amplifying effects on the course of later depression, and serious personal, social and economic consequences throughout the life course. Little has been published regarding socio-demographic determinants of depression and possible mechanisms for the development of depressive symptoms among Puerto Rican youth. This study aims to examine the extent to which life events are associated with the development of depressive symptoms, and how place of residence, parental support, youth self-esteem and youth coping modify that association. METHODS: Secondary analyses were performed of data from the longitudinal Boricua Youth Study (three annual waves between 2000-2004). The sample consisted of 10-13 year old Puerto Rican youth living in New York and Puerto Rico with no depressive symptoms at wave 1, and complete information on depressive symptoms (DISC Predictive Scale which includes 9 significant predictors of depression)at waves 2 and/or 3. RESULTS: Depressive symptoms increase across waves with an increase in total, negative, or positive life events in general; and social adversity, death, and family environment life events specifically. Youth with low coping consistently had a higher number of depressive symptoms than youth with high coping regardless of number of total, negative or positive life events. Youth support from parents was found to be a significant confounder for all types of life events. Parent coping was a significant confounder for social adversity events. DISCUSSION: This study identifies various kinds of life events as risk factors that contribute to the development of depressive symptoms. Early onset depressive symptoms have amplifying effects on the course of later depression, and serious personal, social and economic consequences throughout the life course. Preventing the development of depressive symptoms at an early age should be a priority if we want to optimize the mental health and well-being of youth so that they can reach their full potential. Our findings could inform the development of a first-stage screening tool for youth at risk of developing depressive symptoms in community settings.
THE ASSOCIATION OF ORPHAN AND VULNERABLE CHILD (OVC) PRIMARY CAREGIVING, HOUSEHOLD WEALTH, AND FEMALE AUTONOMY ON WOMEN'S BODY MASS INDEX IN NAMIBIA, SWAZILAND AND ZAMBIA
(2013) Kanamori Nishimura, Mariano Juan; Carter-Pokras, Olivia D; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Background: This dissertation investigates factors associated with orphan and vulnerable child (OVC) caregivers' body mass index (BMI) in Namibia, Swaziland and Zambia. Methods: Secondary analyses were performed using cross-sectional data from Demographic Health Surveys conducted in 2006 and 2007. Manuscript 1 included de facto women from Namibia (n=6,638), Swaziland (n=3,285), and Zambia (n=4,497). Manuscript 2 included de jure women from Namibia (n=6,305), Swaziland (n=2,786), and Zambia (n=4,389). Manuscript 3 included married de jure women from Namibia (n=2,633), Swaziland (n=1,395), and Zambia (n=2,920). Statistical analyses using data from 20-49 year old women included weighted marginal means, logistic regression, and Sobel and Goodman tests. Results: Manuscript 1. OVC caregivers' overweight prevalence ranged from 26.98% (Namibia) to 61.3% (Swaziland). Namibian OVC caregivers were less likely to be overweight than non-OVC caregivers and non-caregivers not living with OVC. Swazi and Zambian OVC caregivers were more likely to be overweight than non-caregivers. In Namibia, women's age modified the effect of the association between OVC caregiving and overweight status. Manuscript 2. Namibian and Swazi OVC caregivers had lower Absolute Wealth Index (AWI) mean scores than non-OVC caregivers and non-caregivers. In Zambia, OVC caregivers had a lower mean AWI score than non-caregivers living with an OVC but a higher mean AWI score than non-OVC caregivers. In all countries, even small increases in household wealth (e.g., being a poorer women - 2 to 3 AWI items) were associated with higher odds for being overweight regardless of women's caregiving status. Manuscript 3. Women's educational attainment increased the odds for being overweight in Swaziland and Zambia, and decreased the odds for being underweight in Namibia. Decision-making autonomy mediated the association between AWI and OVC caregivers' BMI in Zambia (Z=2.13, p=0.03). Conclusions. As Africa is experiencing a nutritional and HIV/AIDS transition, overweight problems among OVC caregivers has emerged and should be addressed. These findings support the World Health Organization's recommendations that African countries should focus on addressing infectious diseases as well as the emergence of chronic diseases. Some African public health systems and OVC programs may face a new overweight epidemic alongside existing ones such as HIV/AIDS, tuberculosis, and malaria.
ASSOCIATION OF SERUM VITAMIN D AND KEY CO-NUTRIENTS IN RELATION TO HYPERTENSION: A CROSS-SECTIONAL STUDY BASED ON NHANES DATA
(2016) Barainca, Pamela; Carter-Pokras, Olivia; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Observational studies demonstrate strong associations between deficient serum vitamin D (25(OH)D) levels and cardiovascular disease. To further examine the association between vitamin D and hypertension (HTN), data from the 2003-2006 National Health and Nutrition Examination Survey were analyzed to assess whether the association between vitamin D and HTN varies by sufficiency of key co-nutrients necessary for metabolic vitamin D reactions to occur. Logistic regression results demonstrate independent effect modification by calcium, magnesium, and vitamin A on the association between vitamin D and HTN. Among non-pregnant adults with adequate renal function, those with low levels of calcium, magnesium, and vitamin D levels had 1.75 times the odds of HTN compared to those with sufficient vitamin D levels (p = <0.0001). Additionally, participants with low levels of calcium, magnesium, vitamin A, and vitamin D had 5.43 times the odds of HTN compared to those with vitamin D sufficiency (p = 0.0103).
Associations among food insecurity, dietary sodium and potassium intake levels, and hypertension: a cross-sectional study based on NHANES 2007-2010 data
(2014) Nothwehr, Ann; Carter-Pokras, Olivia; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Background: Food insecure persons may have diet patterns that include excessive sodium and inadequate potassium. These patterns contribute to greater risks of hypertension. Objective: Evaluate levels of association among food insecurity, dietary sodium and potassium intake levels and hypertension among NHANES 2007-2010 adult participants. Methods: Compared mean usual sodium and potassium intakes as well as mean usual sodium-potassium ratios for food secure and food insecure subpopulations. Developed regression models to predict intake levels and hypertension risk. Results: Mean usual sodium intake is not significantly different for food secure and food insecure participants. Mean usual potassium intake is significantly lower and mean usual sodium-potassium ratio is significantly higher for the food insecure subgroup. Controlling for age and household size, food insecure persons are 43% more likely to be hypertensive than food secure persons. Conclusion: Public health measures to decrease cardiovascular disease risk should include interventions designed for this vulnerable subpopulation.
ASSOCIATIONS BETWEEN AMBIENT PARTICULATE MATTER EXPOSURES, STROKE, AND MARKERS OF CARDIOVASCULAR INFLAMMATION
(2017) Fisher, Jared A.; Puett, Robin C; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Stroke is a leading cause of morbidity and mortality in the United States with 795,000 people experiencing a new or recurrent stroke every year. Identifying modifiable risk factors for stroke should therefore be considered a research priority. While associations between ambient exposure to air pollution and other cardiovascular diseases are well established in the literature, the evidence linking particulate matter (PM) air pollution exposures to the risk of ischemic or hemorrhagic stroke remains equivocal. Furthermore, the exact pathophysiologic mechanisms by which exposure to PM may lead to cerebrovascular events are not yet fully understood. Hypothesized pathways include the mediation of effects through a combination of inflammatory responses, autonomic dysregulation, and/or vascular endothelial disturbances. This dissertation addresses existing gaps in the literature in three separate studies. Two time-stratified case-crossover studies examined the association between short-term PM exposures and stroke risk, one in the Health Professionals Follow-up Study (HPFS) and the other among a large database of Maryland stroke hospitalizations. Conditional logistic regression models were used to examine associations by stroke subtype, population subgroups, and clinically-relevant variables. Our third study took place within the Nurses’ Health Study cohort. Multivariable linear regression models were used to examine the associations between PM and residential distance to road exposures and four inflammatory biomarkers (CRP, IL-6, fibrinogen, and ICAM-1). We found positive significant associations between PM10 and ischemic stroke events in the HPFS cohort, and associations were elevated for nonsmokers, aspirin nonusers, and those without a history of high cholesterol. Concentrations were elevated for both CRP and IL-6 among participants who lived close to a major roadway, but no significant results were found by estimated PM exposure. This work provides additional evidence that PM exposure is associated with ischemic stroke and adds to the current literature that those not currently taking aspirin and those without a history of high cholesterol may be at elevated risk. Although the direct role of inflammatory processes requires more investigation, this work does provide additional evidence that proximity to traffic may influence cardiovascular-related inflammation.
Associations between Urinary Phthalates and Metabolic Syndrome in NHANES 2005-2010
(2015) Haque, Mefruz Salwa; Dallal, Cher M; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Phthalates, commonly used to make plastics more durable, are a group of endocrine disrupting chemicals (EDC), with potential for adverse metabolic consequences. Associations between exposure to 13 phthalate metabolites and the prevalence of metabolic syndrome (MetS) were examined among 5,409 U.S adults ≥ 18 years of age, who participated in the National Health and Nutrition Examination Survey from 2005-2010. MetS was assessed using clinical and questionnaire data. Odds Ratio (OR) and 95% Confidence Intervals (CI) adjusting for age, creatinine and key confounders, were estimated with multivariable logistic regression. Positive associations were observed between individual phthalate metabolites and MetS: (MCOP OR=1.31, 95% CI=1.40, 1.64, p-trend<.01; MCPP OR=1.39, 95% CI=1.09, 1.77, p-trend=0.01). In gender stratified analyses, findings with MCOPP and MCPP were restricted to women only. Phthalate metabolites may increase the prevalence of MetS; however, further studies are needed to better understand the role of EDCs in the development of MetS.
Biomarker Categorization in Transcriptome Meta-analysis by Statistical significance, Biological Significance and Concordance
(2020) Ye, Zhenyao; Ma, Tianzhou; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
With the advancement of high-throughput technology, transcriptomic studies have been accumulated in the public domain. Meta-analysis combines multiple studies on a related hypothesis and improves the statistical power and reproducibility of single studies. However, a majority of existing meta-analysis methods only consider the statistical significance. We propose a novel method to categorize biomarkers by simultaneously considering statistical significance, biological significance (large effect size), and concordance patterns across studies, accounting for the complex study heterogeneity that exists in most meta-analysis problems. We conducted simulation studies and applied our method to Gynecologic and breast cancer RNA-seq data from The Cancer Genome Atlas to show its strength as compared to adaptively-weighted Fisher’s method. We found several major biomarker categories according to their cross-study patterns, and these categories are enriched in very different sets of pathways, offering different biological functions for future precision medicine.
Change in Physical Activity and Associated Factors among Adolescent Girls
(2012) Zook, Kathleen Renee; Rohm Young, Deborah; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Objective: Examine relationships between changes in physical activity (PA) and personal, psychosocial and environmental factors among adolescent girls. Methods: Longitudinal data were analyzed from two cohorts of adolescent girls. Participants were placed into four categories based on PA levels. Active Maintainer-AM, Inactive Maintainer-IM, Adopter-A, or Relapser-R. Anthropomorphic, personal, psychosocial and environmental data were collected. Multivariate logistic regression was used to estimate parameters. Results: In early adolescence, Free/reduced price lunch and PA Self-Efficacy were associated with AM; Race and Friend Support for PA with IM; and Friend Support for PA with R. In later adolescence, Distance to Nearest Park, PA Frequency with Friends, and Global Physical were associated with AM; BMI, Friend Support for PA, PA Frequency with Friends, and Age at Menses, with IM; BMI with A. Conclusion: PA predictors were different across the categories and the predictors were different for early adolescence and later adolescence.
CLIMATE CHANGE RELATED EXTREME EVENTS AND ADVERSE HEALTH OUTCOMES AMONG HEMODIALYSIS PATIENTS
(2024) Song, Hyeonjin; Sapkota, Amir AS; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
The increased frequency and intensity of extreme heat events (EHEs) and wildfires due to climate change are posing significant threats to vulnerable communicates including end-stage kidney disease (ESKD) patients. The specific aims of this dissertation are to Aim 1) Examine the association between EHEs exposure and serum concentrations of sodium and potassium among hemodialysis patients in the Western U.S. (2008-2018), Aim 2) Quantify the mortality and hospitalization risk associated with exposure to 2023 Canadian wildfire-related air pollution in the Eastern U.S., and Aim 3) Investigate how EHEs modify the association between wildfire-related air pollution exposure and the risk of mortality and hospitalization among hemodialysis patients in the Western U.S. (2010-2018). We analyzed health records of patients who receiving hemodialysis treatment at Fresenius Kidney Care clinics. We used the 10°C increase in daily average temperature and daily extreme heat events (EHEs) of each county as the primary exposures. The presence of wildfire smoke plume and wildfire fine particulate matter (PM2.5) concentrations for each clinic were measured using satellite-derived smoke polygons (Hazard Mapping System) and ground-based PM2.5 monitors (Air Quality System). We estimated mean serum sodium and potassium change per 10 °C increase in daily average ambient temperature using random intercepts linear mixed-effects models. We employed a time-stratified case-crossover analysis with conditional quasi-Poisson model to investigate the risks of mortality and hospitalization associated with exposure to wildfire-related air pollution and EHEs. In the first study, a 10°C increase in daily average temperature was associated with 0.43 mEq/L (95% Confidence Interval [CI]: 0.47, 0.59) increase in serum sodium during July-August. The serum sodium was 0.15 mEq/L (95% CI: 0.10, 0.20) higher during EHE days compared to non-EHE days. The serum potassium level did not show a significant change. In the second study, during June-July 2023, the presence of wildfire smoke plume was associated with an 18% increase in all-cause mortality risk (Rate Ratio [RR]:1.18; 95% CI: 1.13, 1.24) and a 3% increase in all-cause hospitalization risk (RR:1.03; 95% CI: 1.00, 1.07). A 10-μg/m3 increase in wildfire-related PM2.5 was associated with a 139% increase in all-cause mortality (RR: 2.39; 95% CI: 1.79, 3.18) and a 33% increase in all-cause hospitalization (RR:1.33; 95% CI: 1.10, 1.62). In the third study, we observed significant interactions between EHEs and wildfire smoke plume for mortality RRs among the hemodialysis patients in the Western U.S. Mortality risk was considerably higher when hemodialysis patients were simultaneously exposed to wildfire smoke plume and EHE compared to wildfire smoke plume alone (RR: 1.52; 95% CI: 1.25, 1.86 vs. RR: 1.15; 95% CI: 1.08, 1.23). We did not observe a significant interaction for all-cause hospitalization. Our findings underscore the need to revise operational and care protocols to prepare for such potential join exposures to extreme events that are exacerbated by ongoing climate change. Future work should focus on developing early warning systems to enhance resilience against such threats.
Comparative Analysis of the Effectiveness and Safety of Drug-eluting Versus Bare-metal Coronary Stents Among Patients Registered in the Multi-Payer Claims Database
(2015) Bermudez, Jessica; Carter-Pokras, Olivia; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
There is conflicting evidence as to whether bare-metal stents (BMS) or drug-eluting stents (DES) are more effective at preventing restenosis. The purpose of this study is to compare the safety and effectiveness of BMS versus DES in the coronary artery using unconventional and potentially more efficient post-market surveillance methods. A retrospective cohort study was conducted of 217,654 Medicare, Medicaid, and private insurance beneficiaries ages 41 years and older who were treated with coronary stenting between January 2007 and December 2010. Incidence of coronary health outcomes was measured for 2-3.5 years after stent implantation using claims data and assessed using Cox proportional hazards regression models stratified by gender and race. At baseline, DES recipients were younger, had higher rates of ischemia and high cholesterol, and had lower rates of prior myocardial infarction and hypertension compared to BMS recipients. Compared to BMS, DES use was associated with a significant reduction of myocardial infarction (Hazard Ratio (HR): 0.811; CI: [0.774, 0.84]), coronary artery bypass graft (HR 0.627; CI: [0.590, 0.666]), and repeat percutaneous coronary intervention (HR 0.910; CI: [0.888, 0.933]) at a median follow-up of 659 days. Use of DES was associated with superior CHD outcomes compared to BMS regardless of gender. Increased event-free probability for DES compared to BMS was seen among whites and Asians for AMI, among whites only for CABG, and across all races for repeat stenting.
COMPLIANCE WITH AGE AT INITIATION OF HUMAN PAPILLOMAVIRUS VACCINE SERIES BY SOCIOECONOMIC STATUS, RACE/ETHNICITY, AND HEALTH INSURANCE COVERAGE AMONG 13-17 YEAR-OLD FEMALES WHO RECEIVED AT LEAST ONE HPV VACCINE SHOT: UNITED STATES, 2011
(2014) Rattanawatkul, Kanokphan; Carter-Pokras, Olivia; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Human Papillomavirus (HPV) vaccine has been shown to prevent cervical cancer. Numerous studies have examined factors associated with HPV vaccine series initiation, but little is known about factors associated with age of initiation of HPV vaccine. Using cross-sectional data from the 2011 National Immunization Survey-Teen, this study examined the relationship between Advisory Committee on Immunization Practices' recommended age at initiation of the HPV vaccine series and socioeconomic status, race/ethnicity, and health insurance among 13-17 year-old females who received at least one HPV vaccine shot (n=5,965). On-time initiation of HPV vaccine series was significantly associated with having public health insurance (AOR: 1.825, 95% CI: 1.266, 2.631). Females with college-graduated mothers (AOR: 0.669, 95% CI: 0.487, 0.918) or household income greater than $75,000 (AOR: 0.746, 95% CI: 0.568, 0.98) were less likely to initiate on-time. Research is needed to further investigate the reasons for late initiation among these subgroups.
COUNTY AND CENSUS TRACT SOCIOECONOMIC ATTRIBUTES OF ESOPHAGEAL ADENOCARCINOMA CASES SEER 15 (2000-2007)
(2011) Ghazarian, Armen Alex; Saksvig, Brit I; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Esophageal adenocarcinoma (EAC) incidence rates have increased among U.S. men. We examined associations between area-level socioeconomic attributes and stage at diagnosis, an important prognostic predictor of survival time. Logistic regression models were developed to estimate odds ratios (OR) adjusted for age, race, gender and year of diagnosis and 95% confidence intervals (CI) for localized and regional versus distant stage by census tract and county level socioeconomic attributes. At the county level, a high percent of foreign born population was associated with distant stage EAC: >15.4%-26.6%, (OR=1.15, 95% CI: 1.04-1.28) and >26.6% (OR 1.16, 95% CI: 1.03-1.31). Median household income from $40.8-$45.6K (OR=1.14, 95% CI: 1.01-1.28) was also associated with distant stage EAC. Conversely, residence in an urban county was associated with localized or regional stage EAC (OR=0.90, 95% CI: 0.82-0.98). Findings regarding area level disparities in EAC stage may inform cancer control efforts.
COVID-19 Vaccine Hesitancy and Uptake in the United States Considered Through the Lens of Health Behavior Theory
(2024) Kauffman, Lauren Emily; Nguyen, Quynh; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
Given the low COVID-19 vaccine uptake rates in many areas of the United States despite their demonstrated safety and effectiveness, COVID-19 vaccine hesitancy and vaccination barriers continue to be critical areas of research in epidemiology and behavioral health science. This series of studies focuses on COVID-19 vaccine hesitancy and vaccination barriers, as they relate to vaccination intention and vaccine uptake, considered in the context of established health behavior theories. The first study is a systematic review of existing research on COVID-19 vaccine hesitancy using one or more health behavior theories as key components of the design or analysis. This study examined the types of theories that are most often used, how they are used, and where research gaps exist. The remaining two studies use data from the U.S. COVID-19 Trends and Impact Survey, a national cross-sectional survey. The second study investigates the association between recent feelings of anxiety or depression and vaccination intention, as well as between these feelings and identifying with specific vaccine hesitancy reasons. The third study examines vaccine hesitancy and barriers among those with chronic illness or disease, a particularly vulnerable population. Factor analysis was conducted using constructs from the Theory of Planned Behavior as a framework, and the results were used in a regression model to investigate the association between these underlying factors and vaccination intention. This research demonstrated the usefulness of the Theory of Planned Behavior, the Health Belief Model, and the 3 Cs Model in existing and future COVID-19 vaccine hesitancy research, as well as identified Protection Motivation Theory as a promising area for future research. Additionally, psychological states were demonstrated to be significantly associated with vaccine hesitancy, adjusting for demographic, socioeconomic, and time factors. Lastly, the Theory of Planned Behavior was found to be applicable to those unvaccinated and with chronic illness, as the construct factor scores developed were significantly associated with vaccine hesitancy (adjusting for the presence of specific chronic conditions and demographic, socioeconomic, and time factors). These associations were also consistently demonstrated in subgroup analyses of participants with specific chronic conditions.