Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
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Item Effectiveness of a Brief Behavioral Smoking Cessation Intervention In A Residential Substance Use Treatment Center(2009) White, Thomas James; Smith, Barry D; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Cigarette smoking is the number one preventable cause of death in the United States (American Cancer Society, 2008). Despite decades of awareness on the dangers of cigarette smoking, many smokers have been unable to successfully quit. One population with little access to smoking cessation treatments is inner city drug abusers in residential treatment centers. Smoking rates among polydrug users in treatment approach 100% (Burling & Ziff, 1988), and half of those treated for alcohol or substance abuse will die of smoking-related illnesses (Hurt, et al., 1996). Nonetheless, a recent survey of residential substance abuse treatment centers found that only 31% of centers provided smoking cessation programs (Fuller, et al., 2007). The relative scarcity of smoking cessation programs offered at such centers is alarming. A residential substance-abuse center setting is, theoretically, an ideal location for the implementation of a smoking cessation program, due to the available resources (Bernstein & Stoduto, 1999). Successful completion of a smoking cessation intervention during drug treatment increases illicit drug abstinence rates by 25% at one year (Prochaska, Delucchi, & Hall, 2004). Nonetheless, studies of smoking cessation programs in residential treatment centers have typically showed low rates of success (Friend & Pagano, 2005), although these programs have typically utilized the group modality and not individualized, one-on-one treatment (Currie, Nesbitt, Wood & Lawson, 2003). It is important to measure the effectiveness of smoking cessation programs delivered in a one-on-one modality in residential treatment centers. The smoking cessation intervention employed in the present study was based on prior behavioral interventions. The effectiveness of this intervention on smoking cessation and short-term (one-month) relapse were assessed. Goodness-of-fit analysis revealed significantly greater rates of point-prevalence smoking reduction or cessation in the active treatment condition compared with the placebo condition; however, when smoking cessation rates were examined alone, there was no significant difference in cessation rates across the two conditions. No sex differences were found in smoking cessation or reduction rates across conditions. Hierarchical linear modeling revealed that sex (being male) and nicotine dependence contributed most significantly to CPD following quit day.Item Neighborhood Level Disadvantage, Race/Ethnicity and Infant Mortality in Washington DC(2010) Amutah, Ndidi N.; Anderson, Elaine A; Hofferth, Sandra L; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examines the effects of neighborhood level disadvantage and individual level characteristics such as race/ethnicity on infant mortality. Social determinants of health theory and ecological theory were used to construct a neighborhood advantage index for Washington DC. Secondary analyses were conducted using linked birth/death certificate and census data from the DC State Center for Health Statistics. Live births (55,938) and infant deaths (607) occurring in Washington DC from 2001-2007 were examined. Multilevel modeling techniques were utilized to determine the relationship between individual and neighborhood level factors on infant mortality. The research questions were: (a) Do women who are comparable on factors such as maternal education and marital status experience different rates of infant mortality by race? (b) Do women living in areas of high disadvantage experience higher rates of infant mortality than women living in areas of low disadvantage? (c) Does the effect of race/ethnicity on infant mortality change if the mother lives in a place of high disadvantage versus low disadvantage? (d) Does having an infant born preterm or low birth weight increase the risk of infant mortality? Whites have the lowest rates of infant mortality (2.8/1000), followed by Hispanics (7.4/1000), with Blacks having the highest rates (15.2/1000) after adjusting for age, education, and marital status. These findings are consistent with previous research affirming a relationship between race/ethnicity and infant mortality. Infants born in disadvantaged neighborhoods are 1.63 times more likely to die before their first birthday than those born in advantaged neighborhoods. The odds for infant mortality compared to Whites decreases especially for Blacks (5.39 to 3.10; 42% change), living in disadvantaged communities even when race/ethnicity was interacted with the neighborhood disadvantage index. This suggests that disadvantage has different consequences for different race/ethnicity populations living in those neighborhoods. The importance of place (disadvantaged or advantaged neighborhood) in relation to infant mortality at the neighborhood level in addition to improving individual level factors is discussed for program development and policymakers. Implications for health disparities, maternal and child health, social support and future public health research are presented.Item The Challenge of Teen Nutrition: An Ecological View of Sociocognitive Influences on Urban, African-American Adolescent Diet Quality(2010) Wrobleski, Margaret Mary; Atkinson, Nancy L.; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The routine food choices that adolescents make impact their nutritional status, health, and their risk of developing chronic illnesses such as heart disease, cancer, and osteoporosis in the future. Nutrient requirements during adolescence are comparable to those in early infancy, emphasizing the importance of a high quality diet for healthy growth and development. A myriad of personal, social, and environmental factors influence adolescents in shaping their dietary intake and quality of diet. Low-income, African-American adolescents in Baltimore were identified as having sub-optimal nutritional intake compared to national dietary recommendations. This study explored the dynamic and relative contributions that factors within three environmental levels (personal, social, and community) made as predictors of diet quality in a sample of low-income, urban African-American adolescents using an integrated Social Cognitive Theory (SCT) / ecological theoretical framework. It was hypothesized that 1) the personal, social, and community environmental levels of dietary influences would all significantly contribute to diet quality, with community environment making the largest relative contribution; 2) self-efficacy for healthy eating moderated the relationship between parental beliefs about nutrition and diet quality; and 3) self-efficacy for healthy eating moderated the relationship between peer eating behaviors and diet quality. There have been very few studies using an integrated SCT/ecological model to explore the dietary influences on adolescent nutrition, especially on this demographic. The significant influence the SCT construct of observational learning has on adolescents was evidenced in this study by the positive relationship found between diet quality, parental beliefs about nutrition, and peer eating behavior. Younger participants in early adolescence and females were predominately guided by their parents' beliefs about nutrition, while males in this study appeared to identify more with their peers' nutrition-related behaviors. This study revealed that parents and peers play important roles in African-American adolescents' food choices and subsequent diet quality. Nutrition interventions should focus on parent-teen interactions and on improving the dietary habits of parents so they may be more effective role models for youth. Nutrition promotion research targeting young African-American men may consider using group interactive behavioral interventions with peers that build and reinforce peer modeling of positive nutrition behaviors.Item Circulating biomarkers of nitro-oxidative stress in young and older active and inactive men(2010) Bjork, Lori; Hagberg, James M; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Oxidative stress markers may be novel factors contributing to cardiovascular (CVD) risk. The purpose of this study was to examine the effects of long-term exercise, age, and their interaction on the plasma levels of the oxidative stress markers oxidized LDL (ox-LDL), nitrotyrosine, and myeloperoxidase (MPO), and to investigate whether these levels correlated with plasma NOx levels. Older (62 ± 2 yr) active (n=12) men who had exercised regularly for over 30 years and young (25 ± 4 yr) active (n=7) men who had exercised regularly for over 3 years were matched to older (n=11) and young (n=8) inactive males. Young subjects showed lower plasma nitrotyrosine levels than older subjects (P = 0.047). Young inactive subjects had higher ox-LDL levels than either the young active (P = 0.042) or the older active (P = 0.041) subjects. In addition, plasma oxidative stress levels, particularly ox-LDL, were correlated with various conventional CVD risk factors, and in older subjects were associated with Framingham risk score (r = 0.49, P = 0.015). The study found no relationships between plasma markers of oxidative stress and plasma NOx levels. The findings suggest that a sedentary lifestyle may be associated with higher ox-LDL levels and that the levels of oxidative stress markers may contribute to CVD risk.Item THE IMPACT OF HEALTH INSURANCE ON CANCER PREVENTION: EX ANTE AND EX POST MORAL HAZARDS(2010) Tang, Li; Jin, Zhe; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The classic model of moral hazard suggests that health insurance may reduce preventive care because the insurer will pay for part of the treatment in case of disease. However, if health insurance covers preventive care as well, the reduced cost of preventive care will encourage the insured to consume more preventive care. These two countervailing effects are referred to as ex ante and ex post moral hazards (Zweifel & Manning 2000). Most studies do not distinguish the two effects, leading to a potentially wrong characterization of moral hazard. Using Medicare coverage as an example, this thesis identifies ex ante and ex post moral hazard effects of health insurance on cancer prevention. As we know, Medicare eligibility rules increase health insurance coverage at age 65. However, some preventive screenings were not covered in Medicare until recently. The different timing of Medicare eligibility and Medicare expansion of preventive care allows me to use a difference-in-differences framework to separate ex ante and ex post moral hazards. I focus on female uptake of breast cancer screening and male uptake of prostate cancer screening, using the Medical Expenditure Panel Survey (MEPS) and the National Health Interview Survey (NHIS). In both datasets, I find evidence in support of ex ante and ex post moral hazards. No evidence shows that people try to delay screening until it has been covered by Medicare. Moreover, the level of prevention and responsiveness to insurance changes vary with demographics, with larger effects among whites and the better-educated. Then I take a second look at the moral hazard problem in the health insurance market using the Health and Retirement Study (HRS). Compared with MEPS or NHIS, the panel nature of HRS allows me to control for individual fixed effects and therefore provides a more stringent test. The major findings on breast cancer screening are consistent. I find strong ex ante and ex post moral hazard effects in it, and individual reactions to Medicare enrollment and Medicare's preventive care coverage vary by factors such as race and income. However, moral hazards on prostate cancer screening is not found, mainly due to data limitation.Item EVALUATION OF ANTIBIOTIC-RESISTANT BACTERIA IN TERTIARY TREATED WASTEWATER, RECLAIMED WASTEWATER USED FOR SPRAY IRRIGATION, AND RESULTING OCCUPATIONAL EXPOSURES(2010) Goldstein, Rachel Elizabeth Rosenberg; Sapkota, Amy R; Maryland Institute for Applied Environmental Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Occupational exposures to vancomycin-resistant Enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) in reclaimed wastewater used for spray irrigation were evaluated. In 2009, wastewater was collected from a tertiary-treatment facility, and reclaimed wastewater, nasal and dermal swab samples from an irrigation site. Samples were evaluated for MRSA and VRE using standard methods, PCR, and susceptibility testing. MRSA and VRE were isolated from all wastewater samples except effluent. While wastewater MRSA isolates were multidrug resistant (98%), no MRSA was isolated in irrigation water or swabs. VRE was isolated in one irrigation water sample. Fewer irrigation workers were colonized with S. aureus (31%) compared to controls (46%), but they harbored more multidrug resistant S. aureus. This is the first study to 1) evaluate antibiotic-resistant bacteria (ARB) in U.S. reclaimed wastewater and resulting occupational exposures, and 2) detect MRSA in U.S. wastewater. The findings suggested that tertiary wastewater treatment effectively reduced MRSA and VRE.Item Parenting Style as a Moderator between Maternal Trauma Symptoms and Child Psychological Distress(2010) Cook, Emily; Leslie, Leigh A; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Current research suggests parents who experience symptoms of trauma transfer distress to their children. The purpose of this study was to understand the possible moderating effect of mothers' parenting style on this relationship. The level of maternal trauma, use of parenting styles, and child psychological distress was examined for a clinical sample (n=113) of mother and child dyads. Results indicated that mothers who experience high levels of trauma symptoms are more likely to parent using authoritarian or permissive behaviors. Mothers experiencing high levels of trauma symptoms who parent with a high use of authoritarian behaviors have children who experience more depression than those whose mothers use fewer authoritarian behaviors. However, mothers experiencing high levels of trauma symptoms who parent with a high use of permissive behaviors have children who experience less depression than those whose mothers use fewer permissive behaviors. The empirical and clinical implications of these findings are discussed.Item DIAGNOSTICS FOR MULTIPLE IMPUTATION BASED ON THE PROPENSITY SCORE(2010) Wang, Jia; Zhang, Guangyu; Epidemiology and Biostatistics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Multiple imputation (MI) is a popular approach to handling missing data, however, there has been limited work on diagnostics of imputation results. We propose two diagnostic techniques for imputations based on the propensity score (1) compare the conditional distributions of observed and imputed values given the propensity score; (2) fit regression models of the imputed data as a function of the propensity score and the missing indicator. Simulation results show these diagnostic methods can identify the problems relating to the imputations given the missing at random assumption. We use 2002 US Natality public-use data to illustrate our method, where missing values in gestational age and in covariates are imputed using Sequential Regression Multiple Imputation method.Item 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.Item The Role of Parental Employment in Childhood Obesity(2010) Benson, Lisa JoAnn; Mokhtari, Manouchehr; Family Studies; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Childhood obesity is a major public health concern, as it has been shown to lead to increased health care costs, reduced quality of life and significant morbidity and mortality. Childhood obesity has been linked to numerous environmental, genetic, and behavioral risk factors. Maternal employment has been shown to exert considerable influence on childhood obesity, however little is known about the role of paternal behaviors in children's overweight and obesity. The current study addresses this important knowledge gap by examining the joint impact of parental influences on children's overweight and obesity as measured by body mass index (BMI). The Child Development Supplement (CDS) of the Panel Study of Income Dynamics (PSID) was used to explore the potential pathways by which maternal and paternal behaviors impact children's health. In particular, this study investigated whether father involvement as measured by paternal weekly work hours plays a significant role in the onset of childhood obesity, while taking into account the influence of maternal weekly work hours on child weight. This study found a significant relationship between maternal employment and child BMI, but found that paternal employment plays a significant role as well. The relative importance of parents' work hours on child body mass outcomes varied with child age, younger children being more affected by maternal work hours and older children impacted more by paternal work hours. This investigation revealed that parental work hours may impact both the quantity and quality of time spent with one's child. Shared parent-child activities found to have an impact on childhood obesity included yard work, laundry, shopping, building or repair work, food preparation, talking and reading. Additionally, this study found that the relative influence of maternal and paternal employment hours on child BMI differed, with paternal work hours associated with lower child body mass outcomes, and maternal employment predictive of increased risk of childhood obesity. These findings point to a complex dynamic between parental employment and child weight. This study's finding that the impact of father's hours of work on childhood obesity is significant indicates that ignoring this factor may potentially lead to biased and inconsistent findings. Thus, results of studies that omit paternal employment hours from their modeling, estimation, and inference must be interpreted with a degree of caution. Given parents' mutual interest in efficiently providing for the health and well-being of their children in terms of relative investments of time and other resources, the findings of this research provide theoretical support for the observed asymmetries in parental contributions to child health production. The results of this study point to the need for programs and policies that support parents in their individual and shared contributions to maintaining healthy weight outcomes in children.