Department: Public Health ![[clear]](close-x.png "Remove this limiter")
82 matches in the database.
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1.
Abdel-Rasoul, Mahmoud Hisham.
A Variance Estimator for Cohen’s Kappa under a Clustered Sampling Design.
Degree: MS, Public Health, 2011, Ohio State University
► Assessing agreement between raters is often required to evaluate the consistency of…
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▼ Assessing agreement between raters is often required to evaluate the consistency of measurements from different raters. Several methods to assess agreement between raters have been previously developed for binary matched pair data (Donner et al. 1996; Donner et al. 2000; Durkalski et al. 1996; Eliasziw and Donner 1991; Obuchowski 1998). The most commonly used coefficient of agreement between raters is Cohen’s kappa statistic (Donner et al. 1996). With the exception of Feder (2006) who proposed a variance estimator for the survey weighted Cohen’s kappa coefficient, previous research related to Cohen’s kappa has focused on study designs where the matched pairs are assumed to be independent. Studies that have developed methods to analyze agreement between raters for clustered study designs have focused on other forms of the kappa coefficient or McNemar’s test. We proposed a variance estimator for Cohen’s kappa under a clustered sampling design. Our study was motivated by the Detroit Middle School Asthma Project (DMSAP) which intended to assess the agreement between parents and students on several asthma related measures (Clark 2010). A large sample variance estimator for Cohen’s kappa under a simple random sampling design has been previously proposed by Fleiss (1969). We used the variance estimator for a proportion under a clustered sampling scheme proposed by Rao and Scott (1992) and the covariance estimator which takes into account the correlation between the proportions in addition to the intracluster correlation proposed by Obuchowski (1998) along with the delta method to obtain a variance estimator for Cohen’s kappa under a clustered sampling design. We conducted an extensive simulation study to assess the performance of the proposed variance estimator under different study conditions. The proposed variance estimator was compared to the variance estimator proposed by Fleiss (1969) relative to the empirical variance. The performance of the proposed variance estimator and the variance estimator under SRS were also compared using a real data example from The Detroit Middle School Asthma Project. The proposed variance estimator performed at least as well as the variance estimator under a simple random sampling design for all study conditions explored. The proposed variance estimator performed better than the variance estimator proposed by Fleiss (1969) under several study conditions, particularly when the correlation between two first raters and the correlation between two second raters was 0.1, and when values of kappa were greater than 0.1. The variance estimator under a simple random sampling design underestimates the true variance for Cohen’s kappa when a clustered sampling design is employed and correlation between raters within a cluster is not negligible.
Advisors/Committee Members: Andridge, Rebecca.
Subjects: Biostatistics
Keywords: Cohen's kappa; Clustered binary data
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2.
Abdullah, Sumayyah S.
Nativity and Health Inequality: Demographic, Socioeconomic, Behavioral and other Predictors of Self-Rated Health Status in U.S.-Born and Foreign-Born Populations.
Degree: PhD, Public Health, 2011, Ohio State University
► Background: Health disparity is an increasingly prominent focus of public health research…
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▼ Background: Health disparity is an increasingly prominent focus of public health research in the US. In numerous prior studies, sociodemographics have been found to be associated with differing health outcomes. Foreign birth and immigrant-related factors add a layer of complexity to health disparity research as the percentage of non US born individuals in the US has risen from 6.9% to 12.4% since the 1950s. However, although research into the association between immigration and mortality and other objective measures of health have been conducted, little study has been done of the subjective and/or actual health status of the foreign born. In this study, we examined the effect of immigration issues on the association between self-reported health status (SRHS) and selected variables in adults. Method: Data from the 1997-2005 National Health Interview Survey (NHIS) were assessed examining selected health variables and covariates of non-institutionalized adults and children. Our sample consisted of 871,701 individuals, at least 18 years of age, who reported their SRHS and immigrant status. Odds ratios were estimated from multivariate logistic regression models. In addition, the interaction between nativity and race/ethnicity was assessed. Logistic regression was utilized to identify predictor variables for SRHS in US and foreign born populations. 95% confidence intervals were used to evaluate statistical significance in this study. Results: During the 1997-2005 period, complete data were available on 136,394 foreign-born immigrants representing 15.65% of the NHIS population sample. Among foreign-born immigrants, 10.9% reported their health status as “not good” compared to 9.2% of US born persons (crude odds ration = 1.21). However after adjustment for important health-related variables including age, presence of comorbid conditions and education, foreign born individuals were found to have a reduced odds of reporting poor health (adjusted odd ration = 0.88). Significant interactions were observed between nativity and race/ethnicity. Most notably, within the Hispanic population the odds of immigrants reporting “not good” health was 21% less than for US natives, a result likely arising because the US born Hispanics were more apt to be engaged in negative health behaviors and report comorbid conditions. Conclusion: This study examines the impact of nativity and other selected variables on SRHS and adds new information to the current available research on the role immigration plays in health inequality. The most important finding was that immigrants were significantly more likely to report “not good” health without adjustment for health-associated variables and covariates. However, when these variables were controlled for in logistic regression models, the foreign born population had a 19% reduced risk of self-rating their health as low compared with US natives. Research into health disparity is important to many areas such as health policy and better understanding of the impact foreign-birth is critical in an increasingly global environment. Future study of the association between nativity and sociodemographic and other factors with health status is needed.
Advisors/Committee Members: Harris, Randall.
Subjects: Epidemiology; Public Health
Keywords: Nativity, Immigration, Disparities, Health Status, Self-Rated, NHIS
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3.
Allen, Angela J.
Distribution, Transmission, Surveillance and Control of Tuberculosis Among Foreign-born Persons in Ohio.
Degree: PhD, Public Health, 2011, Ohio State University
► Objectives: The first aim of this study was to describe the…
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▼ Objectives: The first aim of this study was to describe the distribution and transmission of tuberculosis (TB) among the foreign-born population in Ohio. The second aim was to determine whether time to diagnosis of active TB after entry into the United States could elucidate disease transmission patterns among foreign-born persons. The study also sought to determine the role of the Class B TB referral process in the distribution of tuberculosis among the foreign-born in the United States. Methods: Epidemiologic profiles of foreign-born and U.S. born TB case patients were compared for TB cases counted in Ohio between 1993 and 2006. Logistic regression models were developed to evaluate risk factors for diagnosis of TB at two separate time points; within 2 years and within 5 years after entry into the United States. Lifetest procedures were used to describe survival time and Cox proportional hazards analysis was used to produce hazard ratios for comparison with logistic odds ratios (OR). Results: Region of origin was a risk factor for diagnosis in less than 5 years, and to a lesser extent, diagnosis within 2 years after U.S. entry. When compared to patients from the European region, controlling for age group and site of disease, patients from the African region had the highest odds of being diagnosed within 5 years (OR= 4.06 [95% CI 2.26 - 7.37]) followed by patients from the Southeast Asia/Western Pacific region (OR= 2.02 [95% CI 1.19 – 3.44]) and the region of the Americas (OR= 1.98 [95% CI 1.06 – 3.73]). Gross National Income (GNI) was also an independent predictor of time to diagnosis after immigration to the United States. Patients from low income countries (OR= 3.37 [95% CI 1.84 – 6.29]) and lower middle income countries (OR= 2.33 [95% CI 1.33 – 4.18]) had significantly greater odds of diagnosis in less than 5 years after U.S. entry than patients from high income countries. Significant odds ratios were observed for region and GNI at both time points measured; however, the odds ratios in the 5 year models were of greater magnitude than in the 2 year models for each independent variable. Analysis of Class B TB referral data did not reveal any significant relationships between variables that would indicate systematic gaps in either the overseas medical evaluation or the subsequent follow-up evaluation in the United States. Conclusions: A large proportion of foreign-born TB cases are diagnosed within a short time after entry into the United States, however, time to diagnosis varies significantly depending on the region and the GNI of the person’s country of origin. Class B TB referral does not have a discernable effect on the incidence of TB in Ohio. The methods used to analyze the data used in epidemiologic profiles should be scrutinized to ensure that surveillance is accurately and usefully informing TB prevention and control programs. Novel applications of the insights gleaned from epidemiologic investigation of TB in the foreign-born population should be sought. Paradigms for TB control based on historical data should be questioned and updated when current data reveals changing dynamics.
Advisors/Committee Members: Harris, Randall.
Subjects: Public Health
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4.
Allison, Jessica Chung.
Four-year incidence of diabetic retinopathy in the Los Angeles Latino Eye Study (LALES): Evaluation of how biologic risk indicators and barriers to treatment contribute to disease development.
Degree: PhD, Public Health, 2008, Ohio State University
► Objective: To examine 4-year incidence of diabetic retinopathy (DR) and to assess…
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▼ Objective: To examine 4-year incidence of diabetic retinopathy (DR) and to assess relationships between both biologic indicators and barriers to care on the development of DR. Methods: The Los Angeles Latino Eye Study (LALES) is a population-based study of primarily Mexican-Americans. Participants were considered at risk for DR if both diabetes was present and they were free of DR at baseline. Definite diabetes was defined as either having 1) a self-reported history and treatment of diabetes, or 2) levels of hemoglobin A1C (HbA1c), or 3) random blood glucose of at least 7.0% and 200 mg/100 mL. All participants underwent a standardized ophthalmic examination. DR was detected by grading of stereoscopic fundus photographs using the modified Airlie House classification scheme. Biologic risk factors, such as HbA1c, random blood glucose, systolic and diastolic blood pressure, were assessed to determine its relationship with incidence of DR. Measures impacting barriers to health care, such as insurance status, were also evaluated to determine its relationship to development of DR. Trend tests were done to assess differences in incidence when stratifying by age and duration of diabetes (defined at baseline). Risk variables were analyzed using logistic regression. Results: Of the 893 participants with diabetes who were seen at follow-up, 745 had gradable photographs. Of those, only 412 were free of retinopathy at baseline and were considered to be at-risk for DR at follow-up. The four-year cumulative incidence of DR was 27.9% (115/412). Significant increases in incidence were seen across both increasing age (p=0.04) and increasing duration of diabetes (p<0.001) strata. Biologic risk factors shown to increase risk of DR were smaller waist-hip ratio (OR: 1.4; 95% CI: 0.8, 2.6), longer duration of diabetes (OR: 2.5 to 8.3 for 1-4 years to 15+ years, respectively), higher HbA1c (OR: 1.5; 95% CI: 1.3, 1.7), and an increase in HbA1c level from baseline to follow-up (OR: 2.3; 95% CI: 1.2, 4.3). Being born in the US decreased risk for development of DR (OR: 0.4; 95% CI: 0.2, 0.8). Insulin use (OR: 1.1; 95% CI: 0.5, 2.3) confounded the relationship between waist-hip ratio and development of DR. Significant barriers to care that increased the risk of DR were known history of diabetes (OR: 5.2; 95% CI: 2.2, 11.9), lack of vision insurance (OR: 1.8; 95% CI: 1.0, 3.8), increasing age (OR: 0.96; 95% CI: 0.93, 0.99), and an increase in HbA1c by vision insurance interaction (OR: 1.3; 95% CI: 1.03, 1.5). Primary language spoken (English: OR: 0.9; 95% CI: 0.4, 1.9; Both English and Spanish: OR: 1.3; 95% CI: 0.6, 2.6) was a confounder in the model. Conclusion: Four-year incidence of DR among Latinos is high. Results indicate that this may be due to a combination of both increasing biologic risks as well as increasing barriers to care. High incidence of DR among Latinos suggests the need for initiating screening programs within Latino communities. Biologic indicators and barriers to care found to be significant in this dissertation could be used to identify Latinos that are highly susceptible to developing DR.
Advisors/Committee Members: Wilkins, John.
Subjects: Epidemiology; Ophthalmology; Public health
Keywords: diabetic retinopathy; diabetes; latinos; hispanics; incidence; risk factors; los angeles latino eye study; lales
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5.
Ashbaugh, Hayley Renee.
A Descriptive Survey of Dairy Farmers in Vinh Thinh Commune, Vietnam.
Degree: MPH, Public Health, 2010, Ohio State University
► The Vietnamese dairy industry is a relatively new, rapidly changing system that…
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▼ The Vietnamese dairy industry is a relatively new, rapidly changing system that has offered significant benefits to individual farmers. Because different areas in Vietnam have varying types of opportunities and constraints, farmers face unique challenges in their respective regions of the country. The objective of this study was to describe dairy farms in Vinh Thinh commune, Vinh Phuc province, in order to determine the needs and challenges pertaining to public health of dairy farms in this area. A randomly selected sample size of 25% (31/125) of the farms in Vinh Thinh commune was chosen for this study. Interviews were conducted in July and August of 2007. The questionnaire contained forty-nine questions in the following five categories: general information, veterinary care, milking routine, animal husbandry and worker hygiene. Twenty to thirty minute oral interviews were conducted in Vietnamese and responses were recorded on the questionnaire by staff of the National Institute of Veterinary Research (NIVR). Farms in Vinh Thinh commune were relatively new (mean = 6 years old) with somewhat inexperienced dairy farmers. Farms were small (mean= 4.6 cows/farm), producing moderate amounts of milk per cow (average of 15.2 kg/cow/d), and yet were also the main source of income for 96.8% of farmers. Regarding animal health and hygiene measures of public health concern, 40% or fewer farmers screened their animals for important milkborne pathogens such as Tuberculosis, Brucellosis and Leptospirosis; 6.5% of farmers reported using the California Mastitis Test; and 61.3% of farmers regularly practiced post-milking teat-dipping of their dairy cows. This study reveals the following needs of farmers in this region of Vinh Phuc province: additional education in the areas of animal hygiene and disease prevention, consistency in farmer implementations of hygiene practices, a greater availability and/or utilization of veterinary care and the need to determine further barriers to the success of this type of small dairy farms. This information will be useful to better allocate the resources available to dairy farmers of Vinh Thinh commune. Similar studies should continue to be conducted in order to adequately monitor the state of the developing dairy industry in rural Vietnam and surrounding countries and aid in bringing these systems to more stable and sustainable levels.
Advisors/Committee Members: Hoet, Armando.
Subjects: Agriculture; Animal diseases; Livestock; Public health; Veterinary services
Keywords: dairy, Vietnam, public health, veterinary hygiene, food safety, milkborne disease
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6.
Ashida, Sato.
Social network characteristics and intention to participate in social activity programs at a new senior center.
Degree: PhD, Public Health, 2005, Ohio State University
► Epidemiological studies have shown that socially integrated older adults live longer and…
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▼ Epidemiological studies have shown that socially integrated older adults live longer and healthier lives. Attempts have been made through organizations like senior centers to enhance social integration among older adults, but little is known about the impact of these efforts. This study investigated the characteristics of social networks among older adults living in community settings and whether these characteristics influence older adults’ intentions to participate in new social activities. A total of 126 face-to-face structured interviews were conducted with older adults between the ages of 65 and 85 living in an urban community in Columbus, OH. Addresses were randomly selected from all possible addresses in the area. Recruitment letters were sent by mail, with follow-up phone calls made when phone numbers were available. About 63.5% of the respondents were female, and 89.7% were White. The influence of social network characteristics, social support, companionship, and participation in productive activities on older adults’ intentions to participate in activities at a soon-to-open senior center was explored using hierarchical multiple linear regression. The results indicated a direct influence of social network characteristics on older adults’ intentions to participate in new activities, and some of the influence was mediated by functional features of social networks such as perceived support and companionship. Respondents who had smaller numbers of people in their networks and those with smaller proportions of network members who provided support had lower intentions to participate in new social activities, and thus should be targeted for intervention. It was also found that the construct of companionship and supportive relationship have independent associations with network characteristics and older adults’ intentions to participate in activities. Because the older adults who had lower perceived availability of companionship had higher levels of intention to participate, these individuals are likely to be recruited successfully and benefit by promoting companionship among them. Additional research is needed to investigate other possible mechanisms linking social networks and intentions to participate, such as social influence from network members.
Advisors/Committee Members: Heaney, Catherine A.
Keywords: Social Networks; Social Support; Older Adults
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7.
Aziz, Robeena M.
Utilization of a preclinical model for chemoprevention of esophageal cancer employing a food-based and single- agent approach.
Degree: PhD, Public Health, 2004, Ohio State University
► Cancer incidence estimates for 2003 indicate that 18% of all cancers diagnosed…
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▼ Cancer incidence estimates for 2003 indicate that 18% of all cancers diagnosed originate in the aerodigestive tract, including the larynx, lung and bronchus, oral cavity, pharynx and esophagus. Specifically esophageal squamous cell carcinoma represents over 90% of all esophageal cancer cases. It is the 8th leading cause of cancer and the 5th leading cause of cancer death. Our laboratory has evaluated the chemopreventive potential of certain foods and a variety of single agents, including food-derived and synthetic compounds, in animal models of lung, colon and esophageal cancer. The goal of these studies was to determine the efficacy of food based and single agents for future use in human chemoprevention trials in individuals at high risk for esophageal cancer. Certain foods, particularly fruits and vegetables, contain a number of complex mixtures that possess preventative properties which may be active at multiple stages of carcinogenesis and / or have additive or synergistic effects. Following a food-based approach for cancer chemoprevention, we initially conducted a study to determine if a freeze-dried preparation of blueberries would inhibit N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis. A single-agent strategy for cancer chemoprevention typically involves the use of an agent which targets a specific process in carcinogenesis. Earlier studies have demonstrated that elevated polyamines may play an important role in the development of tumors in the human esophagus. Based on our findings, our second study evaluated the effect of difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, on post-initiation events in NMBA-induced rat esophageal tumorigenesis. Since black raspberries are effective at inhibiting tumors in both during the initiation and promotion / progression stages of carcinogenesis, our third study evaluated whether black raspberries might also exhibit therapeutic effects against esophageal cancer. The results of our studies indicated that freeze-dried blueberries were ineffective as inhibitors of esophageal tumorigenesis in the rat esophagus. Although the black raspberries may be effective during initiation and promotion / progression stages of carcinogenesis, they did not appear to exhibit any therapeutic value in NMBA-treated rats with fully developed esophageal tumors. However, DFMO appears to be an effective chemopreventive agent when administered in the diet during the promotion / progression stages of NMBA-induced tumorigenesis. Together, these findings illustrate the potential of certain chemopreventives to produce diverse effects among animal model systems, and suggest the importance of developing synergistic-based chemopreventives which inhibit multiple processes during carcinogenesis.
Advisors/Committee Members: Stoner, Gary D.
Subjects: Health Sciences, Public Health
Keywords: chemoprevention; N-nitrosmethylbenzylamine; freeze-dried berries
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8.
Bentley, Melissa Ann.
An Assessment of Depression, Anxiety, and Stress among Nationally Certified EMS Professionals.
Degree: MS, Public Health, 2011, Ohio State University
► Among EMS professionals, occupational exposures in mental illness literature are not well-represented.…
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▼ Among EMS professionals, occupational exposures in mental illness literature are not well-represented. Currently, no literature exists examining the prevalence of mental illness in a large national cohort of EMS professionals. As such, the purpose of this study is to address the lack of scientific knowledge and evidence in the field of mental illness among EMS professionals. The objectives of this master’s thesis are three fold. The first objective is to estimate the prevalence and severity of depression, anxiety, and stress among a cohort of nationally certified EMS professionals. Because other healthcare professions may have similar occupational exposures related to mental illness, the second objective of this study is a comparison of nationally certified EMS professionals’ depression, anxiety, and stress prevalence to other healthcare professions. The third objective of this master’s thesis is the determination of differences between cases and controls (defined by the 21- question Depression, Anxiety, and Stress Scale (DASS-21)) from the same cohort with respect to clinical depression, anxiety, stress, and demographic and work-life characteristics. n accordance with previous methodologies, a questionnaire was included as part of the 2009 biennial recertification paperwork mailed to all nationally certified EMS professionals prior to their 2009 expiration date. This questionnaire contained demographic and work-life characteristic items as well as the DASS-21. Three outcome variables of interest were derived from the DASS-21: clinical depression, clinical anxiety, and clinical stress. Any scores above “normal” for each of the outcomes were determined to be a case and controls were defined as those whose scores fell below the case cutpoint. A complete case-control analysis was performed for each of the three outcome variables. Independent variables were chosen based on previous methodologies and plausibility. A total of 15 independent variables were assessed. The prevalence of depression among the cohort was found to be 6.8%, the prevalence of anxiety was found to be 6.0%, and the prevalence of stress was 5.9%. In the final logistic regression models, certification level, service type, general health, exercise, smoking status, and age were found to be statistically significant in each of the depression, anxiety, and stress models. Further, years of experience, race, and education level was found to be unique only to the depression and stress models. Marital status was found to be statistically significant in only the depression and anxiety models. Lastly, gender was unique to the depression logistic model. This study was able to identify statistically significant demographic and work-life characteristic variables that predicted depression, anxiety, and stress. Future research should attempt to follow EMS professionals prospectively to determine specific characteristics associated with occupational traumatic exposure and the development of clinical depression, anxiety, and stress. Likewise, specific research efforts should be undertaken to establish early recognition criteria in EMS professionals to ensure adequate and quick treatment of mental disorders.
Advisors/Committee Members: Crawford, J.Mac.
Subjects: Public Health
Keywords: EMS; prehospital emergency medicine; depression; anxiety; stress; paramedic; EMT
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9.
Bouye, Karen H.
The resource mothers program: how community health workers can reduce low-birth weight among African-American clients in WIC programs.
Degree: PhD, Public Health, 2005, Ohio State University
► In order to help reduce low-birth weight among infants born to African-American…
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▼ In order to help reduce low-birth weight among infants born to African-American women, public health advocates and officials must investigate innovative public health strategies that target these groups of people. Resource mother/lay health advisor type interventions may be a source for reducing low-birth weight among African- Americans. This study aimed to investigate whether and how the Resource Mothers Program reduced low- birth weight among low-income African- American women by comparing women in the Women, Infants, and Children Program (WIC) in Atlanta, Georgia. The study used both qualitative and quantitative research. This study used the following risk factors for reducing low-birth weight among African- American infants: (1) access to and quality of prenatal care; (2) prenatal smoking, drinking, and substance abuse; (3) pregnancies among adolescent mothers and women age 35 years and over; (4) nutritional status; and (5) social support. The two groups studied were women at the Southside Medical Center WIC Clinic (mothers exposed to the Resource Mothers Program) and the Grady Memorial Hospital WIC Clinic (mothers unexposed to the Resource Mothers Program). The quantitative analyses showed that in most categories women at Southside had lower rates of low (or very low) birth weight, than those at Grady. Logistic Regression Model 1, found that mothers at Southside were one-third (OR = .34; 95% CI = 0.16, 0.73) as likely as those at Grady to have a low-birth weight infant. The qualitative analyses showed that nutritional education and social support were the foundations of the Resource Mothers Program. Clients improved their nutritional habits and depended on the resource mothers for social support. Both clients and resource mothers agreed that the program worked, and was an asset to the community. For two reasons, the data supported that the Resource Mothers Program worked. First, after controlling for possible confounders in the logistic regression analyses, the rate of low-birth weight for infants was found to be significantly lower at the Southside Medical Center WIC Clinic. Secondly, the resource mothers and clients agreed that the Resource Mothers Program did work.
Advisors/Committee Members: Steinman, Ph.D., Assistant Professor, Kenneth.
Subjects: Health Sciences, Public Health
Keywords: low-birth weight; resource mothers; WIC programs; social support; nutrition
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12.
Braman, Jade A.
Prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) on Human and Equine Contact Surfaces in a Large Veterinary Teaching Hospital.
Degree: MPH, Public Health, 2011, Ohio State University
► Methicillin Resistant Staphylococcus aureus (MRSA) is an infectious zoonotic and nosocomial pathogen…
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▼ Methicillin Resistant Staphylococcus aureus (MRSA) is an infectious zoonotic and nosocomial pathogen that may be transmitted via direct contact with contaminated surfaces. The purpose of this research was to determine which human and equine contact surfaces in a veterinary teaching hospital were contaminated with MRSA. This research was performed in a large veterinary teaching hospital that receives over 1,200 equine patients annually. Swabs and Swiffer® were used to systematically sample pre-selected human and equine contact surfaces in three target surveillance sections of the hospital, collecting an average of 65 samples per month for a period of 12 months. The samples were then tested to detect the presence of MRSA. Of the contact surfaces sampled 8.5% (66/770) tested positive for MRSA, with an equal proportion observed between human contact surfaces (9.7%, 43/444) and equine contact surfaces (7.0%, 23/326) (p-value 0.19). The top three human contact surfaces contaminated with MRSA were the computers and keyboards (16.6%, 4/24), countertops and cabinets (11.4%, 16/140), and the doors (9.71%, 10/103). Among the equine contact surfaces the feed and water buckets (16.6%, 2/12), surgery tables and mats (15.5%, 7/45), and a pooled sample of halters, hay-bags and muzzles (11.1%, 4/36) had the greatest number of MRSA positive results. Of the MRSA isolates identified in this study 39.3% (26/66) were multi-drug resistant (MDR) with resistance to six classes of antibiotics including beta-lactams of the isolates analyzed genotypically the majority carried SCCmec type IV (34/39). These results are of importance due to the potential occupational risk to the staff and students for community-associated MRSA infections, as well as the possibility of nosocomial equine infections.
Advisors/Committee Members: Hoet, Aramando.
Subjects: Public Health
Keywords: MRSA; MRSA in the environment; MRSA in horses
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13.
Canfield, Beth A.
Participating in a clinical trial: HIV+ women's experiences and decision-making processes.
Degree: PhD, Public Health, 2003, Ohio State University
► The use of drug therapies helps extend and improve the quantity and…
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▼ The use of drug therapies helps extend and improve the quantity and quality of life for HIV+ people. The rapid rate of viral resistance makes continued research into newer therapies vital. Under-recruitment of women into trials may limit health care practitioners' ability to provide optimal care for HIV+ women. This research explored the process HIV+ women used to make decisions about enrolling and continuing participation in clinical trials. Grounded theory, which emphasizes systematic data collection and analysis, guided the qualitative methods. This qualitative study resulted in thick, rich descriptions of HIV+ women's experiences in clinical trials. Audio-taped face-to-face, semi-structured interviews lasted between 45 and 90 minutes. QSR NUD*IST software was used to facilitate data analysis. Open coding, axial coding, data immersion, and discussion with experts elucidated themes and discrepancies in the data. Women older than 18 who were participating in a clinical antiretroviral trial were eligible. Twelve eligible women were interviewed. Six women were Caucasian; six were African-American. The ages of women ranged from 29 to 63. Five women were employed either full or part-time. The decision to participate in a clinical trial was not troublesome for most of the women interviewed. Decisions to join a clinical trial are rooted in a socio-economic reality and may not require agonizing over pros and cons (especially as pros and cons assume a core base of knowledge of other options which was not found to exist here). The decision-making was based also on feelings of desperation (due to existing or potential health decline) and involve trust, altruism, and expectations of personal health benefits. These decisions may need to be re-framed from the rational framework(s) currently in vogue to one incorporating affective and socio-economic constructs. A strong, positive affective relationship with trial health care providers shaped and affected every area of the trial experience, including trial-related decision-making. Overall, these HIV+ women seemed very satisfied with their experiences in clinical trials.
Advisors/Committee Members: Heaney, Catherine A.
Subjects: Health Sciences, Public Health
Keywords: HIV; AIDS; Clinical trial; Women; Experience; Decision-making
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14.
Carmack, Tara Lynn.
A Comparison of Last Observation Carried Forward and Multiple Imputation in a Longitudinal Clinical Trial.
Degree: MS, Public Health, 2012, Ohio State University
► In randomized clinical trials, the presence of missing data presents challenges in…
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▼ In randomized clinical trials, the presence of missing data presents challenges in determining the actual treatment effect of the study. It is particularly problematic in longitudinal studies when patients followed over time withdrawal from the study. Although it is important to anticipate and attempt to prevent these drop-outs in the study design, it is still likely that a significant amount of missingness will be present in the final data. It is important to have statistical methods that effectively analyze data which contains missing values, and produce unbiased results. This study compares several methods for handling missing data in longitudinal trials. The focus is on the single imputation method of last observation carried forward, and compares it to complete case analysis, multiple imputation and two additional versions of multiple imputation where everyone was imputed as if they were actually in the control group (placebo-imputation). We simulated a randomized control trial with a treatment and placebo group and two time points. After creating the data, we imparted missingness in the follow-up time point. We considered three mechanisms for the missing data: missing completely at random (MCAR), missing at random (MAR) and not missing at random (NMAR). The results indicated that in all situations, last observation carried forward produced extremely biased estimates of treatment effect. Both placebo imputations produced similarly biased estimates. Complete case analysis was only valid in the situation where the data was MCAR. Traditional multiple imputation using regression performed the best of all the methods.
Advisors/Committee Members: Andridge, Rebecca.
Subjects: Biostatistics
Keywords: LOCF; Multiple Imputation; missing data; randomized clinical trials
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15.
Chen, Tong.
Chemoprevention of esophageal cancer: investigation of inducible nitric oxide synthase as a chemopreventive target in n-nitrosomethylbenzylamine-induced esophageal tumorigenesis.
Degree: PhD, Public Health, 2003, Ohio State University
► Esophageal cancer is the third most common gastrointestinal malignancy and is the…
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▼ Esophageal cancer is the third most common gastrointestinal malignancy and is the sixth most frequent cause of cancer death in the world. Estimates of cancer incidence in the United States for 2003 indicate that 13,900 citizens will be diagnosed with esophageal cancer. It is usually discovered at an advanced stage and becomes to fatal rapidly. One-year and 5-year survival rates for esophagus cancer are very low. Seventy-five percent of untreated patients with esophagus cancer die within 1 year of diagnosis and 5-year survival rates are only 5-10%. The N-nitrosomethylbenzylamine (NMBA)-induced rat model of esophageal cancer has been used extensively in our laboratory to investigate the mechanisms of tumor development in the esophagus and to evaluate the efficacy of potential chemopreventive agents including whole food and a variety of single agents. Our investigations provide experimental support for chemoprevention trials of esophageal cancer in humans. Nitric oxide (NO) is a single molecular and a high level of NO is synthesized from L-arginine by inducible nitric oxide synthase (iNOS). Increased NO production appears to be associated with many disorders including cancer. Therefore, as shown in many studies, iNOS plays a very important role in carcinogenesis. To investigate the association between iNOS and tumor development in rat esophagus, we conducted a bioassay in which rats were sacrificed at three-week intervals during and following expose to NMBA. Real-time PCR and immunohistochemistry assays have been used to determine mRNA and protein expression of iNOS. The results of this study suggest that overexpression of iNOS is associated with tumor development in the rat esophagus. Based on our findings, we conducted a second bioassay to evaluate a selective iNOS inhibitor, PBIT, and black raspberries as chemopreventive agents targeting the function of iNOS. We observed a statistically significant reduction in tumor incidence and multiplicity in rats fed with PBIT or black raspberries when compared to rats fed with regular diet only. In summary, our data indicate that iNOS plays an important role in esophageal cancer and its inhibitor(s) might be potential chemopreventive agents in esophageal cancer in humans.
Advisors/Committee Members: Stoner, Gary D.
Subjects: Health Sciences, Public Health
Keywords: cancer chemoprevention
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16.
Chiang, Pei-Yu.
Tree-hole Mosquito Surveillance and Control: The Influence of Environmental Factors on Aedes triseriatus Breeding and Egg-laying.
Degree: MPH, Public Health, 2012, Ohio State University
► A nine-week field work was conducted during summer 2010 (July 19 to…
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▼ A nine-week field work was conducted during summer 2010 (July 19 to September 17) to better understand the distribution of the eastern tree-hole mosquito, Aedes triseriatus, with emphasis on the potential environmental factors that may have impacts on its breeding and egg-laying behaviors. Five neighborhoods of Franklin County, Ohio were chosen and ten oviposition traps were set at each location. To examine mosquito preference to habitats, two different elevations and six substrate types were selected and included into the weekly egg surveys. Eggs were then hatched and reared into emergence in the mosquito control facility, followed by identification to species. Weekly total number of eggs among all five locations showed the highest count (6561) in mid August (week 5). Egg counts for Gahanna and Green Lawn Cemetery peaked (471 and 3169, respectively) in week 5 as well. Egg counts for Obetz Memorial Park peaked (2981) a week earlier, while those for Prairie and Hilliard Municipal Park peaked (1764 and 298, respectively) one or two weeks later. Green Lawn and Obetz had significantly more eggs deposited than the others (p= 0.004). No significant difference in mean egg counts among ovitrap sites (of the same location) was observed; however, ovitraps placed at ground level (rather than those at elevation) in Hilliard received significantly more eggs (p=0.004). Seasonal factors such as temperature and other environmental factors in response to the seasonal effects were suggested from the observed variations of egg counts over the nine weeks. Only Green Lawn and Obetz showed positive relationship between temperature and egg-laying. Substrates with darker color showed more egg deposition though not statistically supported. Total 793 Aedes triseriatus and 1480 Aedes albopictus were identified and positive associations in abundance of these two species were observed mostly. Evidence accumulated provides insights to the site selection for local mosquito surveillance and control.
Advisors/Committee Members: Sun, Qinghua.
Subjects: Environmental Health; Public Health
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17.
Chisolm, Deena Brown.
The Role of Perceived Discrimination and Perceived Cultural Competence in Predicting Use of Preventive Health Care Services.
Degree: PhD, Public Health, 2003, Ohio State University
► Racial and ethnic disparities in health care utilization in the United States…
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▼ Racial and ethnic disparities in health care utilization in the United States have been broadly documented. While some of these disparities can be attributed to socioeconomic factors, many studies have found that significant racial disparities remain even after control for variables including income, education, and insurance status. How race and ethnicity impact health utilization beyond socioeconomic factors is an expanding area of research. This study considers the role of two previously unexplored constructs, perceived discrimination and perceived cultural competence, in explaining use of ambulatory and preventive health care services. The data for this study are derived from the Commonwealth Fund 2001 Disparities in Health Care Quality Survey, a national survey including 6,722 people aged 18 and older. Blacks and Hispanics were over sampled to allow for meaningful subgroup analysis. This study employs logistic regression modeling to explain the use of nine ambulatory and preventive services: ambulatory care, physical examination, blood pressure screening, cholesterol screening, Pap testing, mammography, colon cancer screening, prostate cancer screening, and dental care. Independent variables for the model are be derived from the Anderson Behavioral Model for health care utilization using the categories of predisposing, enabling, and need variables. The analysis tests whether the addition of perceived discrimination and perceived cultural competence constructs to Andersen’s traditional predisposing variables decreases the significance of race and whether it improves of models. Analysis also explores whether access to a regular source of care mediates the association between health services use and racial perceptions. Findings support the hypothesis that the addition of perceived discrimination and perceived cultural competence measures to a behavioral model predicting service use significantly improves the fit of the model in four of the nine services studied and found that in selected services these variables explained some or all of the race effect that remained after control for socioeconomic variables. A mediating role for regular source of care was also supported in some services. This study provides policy makers with an enhanced understanding of the role of racial perceptions in health services us that can be used for informed policy development.
Advisors/Committee Members: Pathak, Dev S.
Keywords: Health Disparities; Discrimination; Cultural Competence; Minority Health; Preventive Services
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18.
Choi, Youn Su.
Risk Factors for Childhood Agricultural Injury.
Degree: MS, Public Health, 2010, Ohio State University
► Objective. This study aimed to evaluate the effect of reaction time, its…
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▼ Objective. This study aimed to evaluate the effect of reaction time, its derived variables IQ, postural sway (steadiness), safety courses, and age with respect to childhood agricultural injury (CAT) resulting from the chore of feeding animals by hand. We assume that shorter reaction time is associated with lower CAI risk, controlling for potential covariates. Methods. The target population of this study was 4-H youth in the Central Ohio Area between 9 and 18 years old who were exposed to agricultural hazards. This thesis examined the subsets that were exposed to the possibility of injury while feeding an animal by hand (except pets). The larger cohort study was designed to be longitudinal. Data were collected during 1999-2001 in three stages: pre-baseline demographic information, baseline testing, and the daily diary (“Daily Record Books,” or DRB) which contains the amount of time spent on each agriculture-related chores over a period of 13 weeks. A model of the reaction time (Krieg, Chrislip, & Russo, 1996) was used to compute the following variables: the mean reaction time (MRT), the initial performance level (L1), the performance limit (L∞), the learning rate (l), and the fatigue rate (f). Gender difference in factors such as age and derived variables from the reaction time data were examined using t-test and chi-square test. Longitudinal analysis by using residual pseudo-likelihood was used to estimate the expected injury rate and risk factors. Results. The results suggest that there are several differences in injury rate between boys and girls. The general safety course helped to prevent injuries in boys. The expected injury rate of those who had not taken the general safety course was 1.5 times higher than that of those who had taken the course in boys. Age and the fatigue rate of girls were an important factor in the expected injury rate. The expected injury rate of boys increased as the standard deviation of the reaction times decreased and as the week passed. For girls, the expected injury rates of the first two age groups were significantly different from that of the oldest group (p = 0.0003) and the second age group had the highest expected injury rate. The expected injury rate of girls increased as the fatigue rate increased and decreased as MRT increased. Conclusion. We found that gender difference in injury rates and risk factors including age, safety class, and psychomotor skills are associated with farming related injuries in children and adolescents. Interestingly, we found that a lower MRT coincided with higher expected injury rate of girls, and the lower standard deviation of the reaction time coincided with higher expected injury rate for boys. More studies are warranted to determine whether high risk work environment is associated with lower reaction time.
Advisors/Committee Members: Wilkins III, John.
Subjects: Biostatistics
Keywords: Childhood Agricultural Injury; Risk Factors; Reaction Times
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19.
Clark, Brenda Rose.
Development of an Air Pollution Asthma Risk-Screening Model for Ohio Elementary Schools.
Degree: PhD, Public Health, 2012, Ohio State University
► Background: According to data from the most recent Ohio Family Health Survey…
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▼ Background: According to data from the most recent Ohio Family Health Survey (2008), 15.4 percent of Ohio children have been told that they have asthma. Asthma-related school absenteeism has been linked with environmental factors in indoor settings, which may include schools. Objective: Recognizing the significant impact of asthma on Ohio’s families, the importance of the school environment, and the paucity of relevant air quality data for schools, this study developed an Asthma Risk Screening Indicators (ARSI) predictive model for school indoor air quality (IAQ) and asthma risk based on indoor and outdoor air pollution data. Methods: The outdoor air arm of the ARSI was derived from two extant databases of outdoor air toxic releases: the Risk-Screening Environmental Indicators (RSEI) model, which quantifies TRI emissions; and the 2005 National-Scale Air Toxics Assessments (NATA), which quantifies both industrial chemical emissions and risk due to traffic (onroad mobile sources). The indoor air component was closely modeled after recommended school inspection guidelines previously used in Ohio schools under Jarod’s Law and developed with assistance from a trained sanitarian. Indoor and outdoor air monitoring in 13 central Ohio elementary schools representing a range of ARSI scores was conducted to validate the two submodel components of the ARSI model. Allergens (n=8) in indoor settled dust were analyzed, and particulate matter (PM), black carbon (BC), and endotoxin over five days during each of two seasons, fall and winter or winter and spring, were also measured. Physician-diagnosed asthma (PDA) prevalence and respiratory morbidity were assessed by surveying fourth graders in 13 central Ohio elementary schools during the 2010-2011 school year using a validated questionnaire. The ARSI model indicators were compared to measured indoor and outdoor air pollution levels and to asthma prevalence and respiratory morbidity to test their predictive significance. Results: 10.2% of students surveyed in 13 schools reported PDA. An additional 37% without PDA reported symptoms consistent with asthma potentially suggestive of undiagnosed asthma. Of students with PDA, 76% reported symptoms suggestive of poorly controlled asthma. High levels of secondhand smoke (SHS) exposure were associated both with PDA (p=0.05) and with respiratory symptoms (p<0.0001). Both School RSEI Score (p=0.05) and NATA ORMPC (p=0.006) were found to be predictive of school-level PDA. Nearly 50% of classrooms inspected had CO2 levels exceeding the American Society for Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) standard of <700ppm above outdoor levels. Further, these high CO2 levels were associated with objective indoor air measures as well as with student reported respiratory symptoms. Conclusions: This study provided evidence-based research that informed the generation of an asthma risk-screening indicators (ARSI) model developed from extant data and school inspection data. Once validated, the ARSI model may be used by local, state, and national government and communities to both screen for at-risk schools and inform mitigation strategies.
Advisors/Committee Members: Buckley, Timothy.
Subjects: Environmental Science; Public Health
Keywords: air pollution, asthma, respiratory morbidity, traffic, predictive model
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20.
Cuyun Carter, Gebra B.
FOOD INTAKE, DIETRAY PRACTICES,AND NUTRITIONAL SUPPLEMENT USE AMONG THE AMISH.
Degree: PhD, Public Health, 2008, Ohio State University
► Research suggests that the age-adjusted incidence rates of cancer are 40% lower…
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▼ Research suggests that the age-adjusted incidence rates of cancer are 40% lower in the Amish as compared to the non-Amish in Ohio. Nutritional intake and dietary habits are behavioral factors that may be crucial in the prevention of cancer. Unfortunately, there is a lack of population-based research among the Amish examining dietary behaviors. The Amish are a unique group of individuals because of the homogeneity of many lifestyle habits that may not have changed drastically over the years nor are heavily influenced by mainstream culture. Exploring the differences between the Amish and non-Amish in regards to food intake, dietary behaviors, and nutritional supplement intake creates the possibility of generating hypotheses regarding any diet-cancer relationship. This cross-sectional study consisted of face-to-face interviews conducted with a random sample of 134 Amish adults residing in Holmes County, Ohio and a random sample of 154 non-Amish individuals that lived in the same geographical region. The questionnaires took included items addressing dietary practices, a 24-hour dietary recall, and nutritional supplement use. The results indicated that there were differences among the Amish and non-Amish in regards to the sources of food items, how the food was prepared and stored, and what was reportedly consumed, as well as nutritional supplement use. At the individual level, the adjusted analyses suggested that the Amish reported consuming fewer servings of vegetables, and had a lower percentage of energy from monounsaturated fatty acids (MUFA) (men only) and polyunsaturated fatty acids (PUFA) compared to the non-Amish. The Amish, as compared to the non-Amish, reported consuming a greater amount of energy intake (men only), whole grain servings (women only), and a greater percentage of energy from saturated fat. Reported intake of at least one type of nutritional supplement was higher among the Amish compared to the non-Amish. These results provide further insight and direction into investigating various relationships between dietary factors and cancer in the future; as well as additional diet-chronic disease associations. The findings provide a more comprehensive understanding of the food source, storage, preparation, subsequent intake of food, and supplement use among the Holmes County Amish community.
Advisors/Committee Members: Ferketich, Amy.
Subjects: Public health
Keywords: Amish; diet; nutritional supplements
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21.
Dailey, Sophia R.
Microbiological Quality of Milk Produced in Urban and Peri-Urban Farms in Central Ethiopia and its Public Health Impact.
Degree: MPH, Public Health, 2011, Ohio State University
► Ethiopia has a large potential for dairy development and much focus has…
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▼ Ethiopia has a large potential for dairy development and much focus has been placed on market demand and productivity. As the industry grows, it is imperative to focus on food safety and quality standards that will increase productivity and trade capacity and improve public health. One active approach being taken is the implementation of a milk quality-based payment system. To help implement quality standards and determine the public health significance of milkborne pathogens, a pilot study was performed to establish baseline data on the microbiological quality of milk throughout central Ethiopia. Fresh bovine milk samples were taken from individual farmers (n=119) and combined bulk tanks (n=29) from collection centers in Selale, Asela, Akaki, and Debre Zeit to determine the prevalence of Salmonella enterica and Staphylococcus aureus. To further assess the public health impact, isolates of S. aureus were tested for antimicrobial resistance and the presence of enterotoxigenic genes. In addition, surveys were administered to participating farmers and collection center owners to gain an understanding of milking practices on urban and peri-urban farms in central Ethiopia and to determine possible risk factors of milk contamination. S. aureus was present in 26.1% of pooled samples and 51.7% of combined bulk tank samples. Of the strains isolated from pooled milk, 83.9% were resistant to penicillin, ampicillin, tetracycline, or a combination of the three with the highest proportion resistant to penicillin. Enterotoxigenic genes were found among 25.8% of the isolates with sea accounting for the highest proportion. The pulsed field gel electrophoresis (PFGE) analysis resulted in three different clusters with clonal relatedness between strains within geographical locations. We found a 0% prevalence of Salmonella in both pooled and bulk tank samples. There were very few differences in milking behaviors between regions. Three factors associated with recovery of S. aureus from milk are; administering a pre-test to new cows prior to entering the herd, high levels of production, and assigning a specific individual to only milk. It is clear that S. aureus is present in a significant proportion of milk produced on urban and peri-urban farms and poses a potential public health threat due to the presence of staphylococcal enterotoxin (SE) genes. Determining and implementing quality standards for a quality-based payment system is one step towards encouraging farmers to produce quality milk and in turn improve public health. It is also essential to ensure farmers have the knowledge and resources to meet the standards set forth.
Advisors/Committee Members: Gebreyes, Dr. Wondwossen.
Subjects: African Studies; Agriculture; Epidemiology; Public Health; Veterinary Services
Keywords: food safety, quality standards, Staphylococcus aureus, dairy
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22.
Darbha, Subrahmanyam.
Reproductive Health Trends In Female Sex Workers In Madagascar.
Degree: MS, Public Health, 2011, Ohio State University
► The first objective of this study was to identify inconsistencies in implementation…
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▼ The first objective of this study was to identify inconsistencies in implementation of diagnostic algorithms for gonorrhea/chlamydia (GC/CT) and bacterial vaginosis/trichomoniasis (BV/TV) diagnosis in female sex workers (FSWs) in Madagascar. Using data from clinical charts, we arrived at algorithm-based diagnoses and compared these to diagnoses recorded by clinicians implementing the same algorithms. The second objective was to identify predictors of inconsistencies between algorithm and clinician diagnoses using generalized estimating equation (GEE) logistic regression modeling. Data were collected between 2003 and 2009 and included 45,021 visits from 13,080 FSWs. We identified disagreement between algorithm and clinician diagnoses of GC/CT in 19.39% of visits and BV/TV in 5.95%. The Kappa measures of agreement for GC/CT and BV/TV were 0.56 and 0.52 respectively. Healthy vaginal pH (below 4.5), FSWs in all age categories, and presence of cervicitis or cervical motion tenderness were each identified as significant predictors of discordance in clinician and algorithm diagnosis.
Advisors/Committee Members: Wilkins III, J. R.
Subjects: Biostatistics; Epidemiology; Health Sciences; Medicine; Public Health; Statistics; Womens Studies
Keywords: Algorithm; Gonorrhea; Chlamydia; Bacterial Vaginosis; Trichomoniasis; FSWs; Female Sex workers; Kappa; GEE; Logistic Regression
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23.
Deng, Wei.
Multiple imputation for marginal and mixed models in longitudinal data with informative missingness.
Degree: PhD, Public Health, 2005, Ohio State University
► The method of multiple imputation by Rubin (1978) calls for imputing draws…
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▼ The method of multiple imputation by Rubin (1978) calls for imputing draws from a predictive distribution and incorporates the sampling variability due to the missing values. If data are missing at random in the sense of Rubin (1976), it is well known that multiple imputation based on the correct missing data model, when used along with maximum likelihood, yields consistent estimators and valid inference. However, multiple imputation for longitudinal data, and in the case where missingness is not at random, has not been well studied. In this thesis, I consider longitudinal data with informative missingness, where the missing data process depends on the individual random effects. I propose a multiple imputation method based on a conditional linear mixed-effects model with summary measures for missing data as additional fixed effects, and implement this method using Markov Chain Monte Carlo. Furthermore, when the complete data is to be analyzed using a marginal model, another major approach for the analysis of longitudinal data, imputation can be performed based on a corresponding mixed-effects model. In this setting, it is of interest to study the validity of the inference since the imputation and analysis models differ. I conduct a simulation study to compare the performance of estimators under a variety of circumstances. Results show that the proposed multiple imputation approach corrects bias caused by ignoring the missing data mechanism, and the inference is fairly robust to the imputation model.
Advisors/Committee Members: Shen, Lei.
Keywords: Generalized estimating equations, non-ignorable missingness, dropout, Markov chain Monte Carlo (MCMC), Gibbs' sampler
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24.
Edwards, Colin.
Exposure to loud noise and risk of acoustic neuroma.
Degree: PhD, Public Health, 2007, Ohio State University
► This dissertation presents three related investigations that evaluate the previously reported association…
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▼ This dissertation presents three related investigations that evaluate the previously reported association between loud noise exposure and the risk of acoustic neuromas, as well as the proposed biological basis for the association. The goal of the first investigation was to examine further the role of loud noise in acoustic neuroma etiology. In a population-based case-control study conducted from 1999-2002 in Sweden, reports of occupational and nonoccupational loud noise exposure of 146 acoustic neuroma cases and 564 controls were compared. Individuals reporting loud noise exposure from any source were found to be at increased risk for acoustic neuromas. The findings of an increased risk of acoustic neuromas with loud noise exposure support previous research. The goal of the second investigation was to further examine the association between noise exposure and acoustic neuroma using an objective measure of exposure. A total of 793 acoustic neuroma cases were identified between 1987 and 1999 from the Swedish Cancer Registry, to which 101,756 controls were frequency matched. Occupational information, available for 599 of the cases and 73,432 of the controls, was obtained from censuses and linked to a job exposure matrix. Of three studies of noise exposure and acoustic neuroma risk to date, this is the first to use a job exposure matrix to assess exposure. Contrary to previous study results the findings do not demonstrate an increased acoustic neuroma risk related to occupational noise exposure. A mechanism of acoustic neuroma tumorigenesis during the cellular repair process following acoustic trauma has been proposed, whereby cellular division results in DNA replication errors which may in turn lead to chromosomal changes essential for neoplastic transformation. In the third investigation, an extensive literature search was conducted to evaluate the biological plausibility of this hypothesis. The tumor typically involves the vestibular rather than the acoustic division of the eighth nerve, however intralabyrinthine and cochlear nerve schwannomas have been reported. Additionally, evidence of vestibular damage in rodents has been demonstrated following acoustic trauma. The proposed hypothesis is therefore plausible, however further research is needed to elucidate the precise biological basis for the association between loud noise and acoustic neuromas.
Advisors/Committee Members: Harris, Randall.
Subjects: Health Sciences, Public Health
Keywords: Acoustic neuroma; noise; case-control studies; risk factors; tumorigenesis
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25.
Elliott, Christopher S.
The Chemoprevention of Lung Cancer Using Non-Steroidal Anti-Inflammatory Drugs (NSAIDs).
Degree: PhD, Public Health, 2003, Ohio State University
► A number of chronic inflammatory conditions are associated with increased risks of…
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▼ A number of chronic inflammatory conditions are associated with increased risks of cancer. One of the key features of chronic inflammation is over-expression of the inducible enzyme, cyclooxygenase-2 (COX-2), which is responsible for conversion of arachidonic acid into molecular mediators of inflammation called prostaglandins. A host of recent studies suggest that COX-2 and its byproducts play a role in the development of certain types of cancer. Epidemiologic investigations have consistently shown that regular use of COX-2-inhibiting, non-steroidal anti-inflammatory drugs (NSAIDs) decreases the risk of colon cancer and breast cancer, and selective studies have noted NSAID-associated risk reductions for several other malignancies. However, one major type of cancer that has not been thoroughly investigated for NSAID effects is lung cancer. To better understand the effect of regular use of NSAIDs on lung cancer development we undertook a case-control study of lung cancer, matching cases and controls for pack-years of cigarette smoking, as well as age and gender. In all, data for 384 cases from the Arthur G. James Cancer Hospital (Ohio State University, Columbus, Ohio) and 384 controls comprising participants in cancer screenings (breast and prostate) at the same institute were compiled for study. Using the methods of logistic regression, we observed an overall protective effect for NSAIDs against the development of lung cancer (adjusted OR=0.52, 95% CI=0.38 - 0.72). A decrease in risk was observed in both men (adjusted OR=0.58, 95% CI=0.38 - 0.87) and women (adjusted OR=0.44, 95% CI=0.26 - 0.74). Likewise, significant protective effects of NSAIDs were observed for squamous cell carcinoma (adjusted OR=0.56, 95% CI=0.34 - 0.93) and large cell carcinoma (adjusted OR=0.32, 95% CI=0.14 - 0.72), and a suggestive effect was present for adenocarcinoma (adjusted OR=0.68, 95% CI=0.43 - 1.07). There was also a significant dose response of decreasing relative risk with amount of NSAID use (trend test, p<0.001). These results point to possible chemopreventive effects of NSAIDs against lung cancer in cigarette smokers and suggest a need for further molecular and clinical investigations of the role of COX-2 in lung carcinogenesis.
Advisors/Committee Members: Harris, Randall.
Subjects: Health Sciences, Public Health
Keywords: Lung Cancer; Inflammation; Cyclooxygenase; COX-2; Non-Steroidal Anti-Inflammatory Drugs; NSAIDs; Epidemiology; Case-Control Study
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26.
Fernandez, Antonio Ramon.
An Assessment of the Relationship between Emergency Medical Services Work-life Characteristics, Sleepiness, and the Report of Adverse Events.
Degree: PhD, Public Health, 2011, Ohio State University
► Literature examining sleepiness among the Emergency Medical Service (EMS) workforce, is limited.…
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▼ Literature examining sleepiness among the Emergency Medical Service (EMS) workforce, is limited. Because of the risks associated with sleepiness identified in other populations, and the importance of EMS with respect to public health and safety, there is a critical need to better understand how sleepiness and shift work may affect the EMS professional. Accordingly, the aims of this dissertation were to 1) quantify clinically significant excessive daytime sleepiness and identify related demographic and work-life factors, 2) quantify error-related events in EMS and assess the relationship between shift length, sleepiness and error-related events, 3) quantify occupational injuries or illnesses and assess the relationship between shift length, sleepiness and occupational injuries or illnesses, and finally 4) quantify negative impacts on personal and professional relationships among EMS professionals and examine the relationship between shift length, sleepiness, and negatively-affected personal and professional relationships. It was hypothesized that there was a positive association between EMS work-life characteristics, clinically-significant sleepiness, and the report of adverse events. In order to complete the aims described above, the Longitudinal Emergency Medical Technicians Attributes and Demographics Study (LEADS) Sleep and Shift Work Survey, which included the Epworth Sleepiness Scale, was created and analyzed. Participants were selected for this study based on prior responses to LEADS. Specifically, in an attempt to survey only those whose main job was as an EMS professional, exclusion criteria dictated that individuals who reported on a previous LEADS from 2005-2007 that they were a volunteer were excluded. All non-volunteers during the same time period who indicated that they had been absent from work in the last 12 months due to a work related injury or illness were included in the sample (n=442). A simple random sample of non-volunteers who had not missed work due to a work-related injury or illness from 2005-2007 were also included for recruitment (n=1,463). The final response rate for the survey was 67.2%. Results from this study indicate that 38% of the study population could be classified with clinically significant excessive daytime sleepiness. Moreover, extended shift length was associated with clinically significant excessive daytime sleepiness (OR: 1.79; 95% CI: 1.20-2.65; p-value = 0.004). After accounting for confounding and effect modification, sleepiness and extended shift length were associated with three outcome variables of interest: error-related events, occupational injury or illness, and negative impacts on relationships with family and friends (p-value <0.05). However, while sleepiness was significantly associated with negative impacts on relationships with co-workers (p-value <0.05), extended shift length was not. These findings are important because they revealed that a large proportion of nationally-certified EMS professionals could be classified with clinically significant excessive daytime sleepiness and extended shift length was significantly associated with clinically significant excessive daytime sleepiness in a multiple logistic regression model. It is also important for leaders in the field of EMS to take note that, in this study, sleepiness and extended shift length were related to adverse events among EMS professionals.
Advisors/Committee Members: Crawford, John Mac.
Subjects: Medicine; Public Health
Keywords: Emergency Medical Services; Sleepiness; Shift Work; Occupational Injury; Medical Errors
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27.
Freshwater, Julie L.
Impact of Antimicrobial Use on the Resistance of Pseudomonas aeruginosa in the Intensive Care Unit Setting in a Large Academic Medical Center.
Degree: PhD, Public Health, 2010, Ohio State University
► It has been previously demonstrated that areas within the hospital that have…
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▼ It has been previously demonstrated that areas within the hospital that have the highest rates of antimicrobial resistance also have the highest rates of antimicrobial use (AU). The intensive care unit setting is one of the areas within the hospital that has the highest rate of antimicrobial use. Measures of hospital and unit specific AU is assuming increasing importance for understanding the dynamics of antimicrobial resistance at the population level. Data obtained from electronic order entry paired with antibiograms yielded a practical approach to analyze relationships between antibiotic usage and corresponding resistance. We found significant correlations with ciprofloxacin and tobramycin use and imipenem resistance. There was a nonstatistical correlation between imipenem use and imipenem resistance (r = 0.29 for 36 months) but it did indicate a positive correlation. There were also correlations in the pairings of drug and corresponding resistances—inverse correlation for ciprofloxacin use and ciprofloxacin resistance (r = -0.88) and a positive correlation with tobramycin use and tobramycin resistance (r = 0.93). Since changes in AU are paralleled by changes in the prevalence of resistance, application of these methods enable hospitals to monitor antibiotic stewardship program interventions with corresponding changes in the rate of resistance after implementation. Building upon the results from the ecological approach, explored the relationship of antimicrobial use, resistance patterns and risk factors pertinent to specific intensive care units. A case- control study was conducted utilizing patient isolates positive for P. aeruginosa (PA). Cases (n = 78) were patients with positive imipenem-resistant (IRPA) isolates from blood and respiratory cultures. Controls (n = 125) were patients with positive susceptible P. aeruginosa (SPA) isolates. Risk factors analyzed included prior antimicrobial use, comorbid conditions and demographic variables. Time at risk greater than 29 days (odds ration [OR], 3.1), ventilator (OR 6.5), prior hospitalization at another facility (OR 2.5), diabetes (OR 2.8), hospitalized due to an accident (OR 0.3), and prior linezolid use (OR 0.1) were associated with isolation of IRPA. Our final study analyzed the relationship of prior antimicrobial exposure and other risk factors for acquiring a multidrug-resistant strain of P aeruginosa (MDRPA). We chose a case-case-control design comparing patients with MDRPA isolates (n = 90) to tempero-spatially matched controls without a PA infection (n=273). Time at risk greater than 29 days (odds ration [OR], 13.11), ventilator (OR 6.10), bronchoscopy (OR 2.37), extended care facility stay (OR 3.39), BMI over 30 (OR 2.45), and receipt of blood products (OR 2.32) were associated with isolation of MDRPA. The second case group (n=108) consisted of patients with a susceptible P aeruginosa infection (SPA) compared with a second group of control patients (n=320). Time at risk 15 – 28 days (OR 2.05), ventilator (OR 3.19), bronchoscopy (OR 1.66), extended care facility stay (OR 2.19), BMI over 30 (OR 3.11), and receipt of blood products (OR 2.68) were associated with isolation of SPA.
Advisors/Committee Members: Harris, Randall E.
Subjects: Health care; Pharmacology; Public health
Keywords: antimicrobial use; Pseudomonas aeruginosa; antimicrobial resistance; multidrug-resistance; case-case control study; case-control study; ecological study
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28.
Fujishiro, Kaori.
Fairness at work: its impacts on employee well-being.
Degree: PhD, Public Health, 2005, Ohio State University
► While for decades, fairness at work has been an important research topic…
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▼ While for decades, fairness at work has been an important research topic in the field of organizational behavior, only recently has fairness gained attention among occupational stress researchers. In the last few years, a small but growing literature has found associations between a lack of fairness at work and a decline in employee health indicated by lower self-rated health status, increased sick leave, and more psychiatric disorders. In spite of the increasing attention to fairness, the literature has not yet established a framework to link work environment, fairness at work, and employee health and well-being. This study proposes an integrative framework, identifies the underlying structure of fairness at work, and examines the role of fairness at work in the occupational stress process. Employees at furniture company distribution centers participated in the study (n = 357). They completed self-administered questionnaires in their worksites. Fairness at work was measured with items derived from interviews with another group of employees in a previous study. Traditionally studied constructs in occupational stress research (job stressors, job control, social support) and employee well-being variables (job satisfaction, global job strain, psychological well-being) were also measured. Confirmatory factor analysis and linear regression were conducted to analyze the data. Five highly correlated factors were identified for fairness at work: unbiased and respectful treatment of employees, receptivity to employee voice, recognition of employee efforts, willingness to help with problems/special circumstances, and concern about employee well-being. A sixth factor, fairness perception about wages, was also identified. A lack of perceived fairness was negatively associated with employee well-being. This study also found that perceived fairness at work moderates the relationship between workload and job strain; that is, high workload was associated with high strain only when perceived fairness was low. In addition, fairness mediated the relationship between role conflict and job-related well-being. These findings have implications for workplace interventions. Since this was a cross-sectional study, the causal link implied in the analysis needs to be confirmed with longitudinal studies. Nevertheless, the findings show that fairness at work potentially plays an important role in understanding occupational stress and in enhancing employee well-being.
Advisors/Committee Members: Heaney, Catherine A.
Keywords: Fairness at work; Organizational justice; Occupational stress; Social support; Job satisfaction; Psychological well-being
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29.
Galos, Dylan Louis.
Differences Between Scientific Experts and Residents of a Community in Columbus, OH in Perceptions of Brownfield Sites and Their Effects on Health.
Degree: MS, Public Health, 2011, Ohio State University
► Brownfield sites, defined by the U.S. EPA as "real property, the expansion,…
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▼ Brownfield sites, defined by the U.S. EPA as "real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant," are a problem in many urban areas. In addition to potential chemical hazards, they pose other experiential and physical hazards to the communities in which they exist. This community-based participatory research study examined the differences between residents of Weinland Park, a community in Columbus, Ohio and experts in environmental science about their perceptions of hazards, health impacts, necessary actions and methods of seeking information as they pertain to brownfields. Results suggested a need for comprehensive risk communication to build a common language between these lay and expert populations. While residents knew there were contaminated sites in their neighborhood, many did not know the term brownfields. Experts showed a greater familiarity with chemical hazards than residents, but both groups had similar perceptions of experiential and physical hazards. Both groups suggested that poverty can increase a population's vulnerability to health effects from brownfield sites due to prolonged exposure to chemicals and delayed action. Experts outlined process-based methods of communication including a community-based method called "porch chats." Both groups identified a need for partnership between community and government entities to elicit effective action in brownfield redevelopment.
Advisors/Committee Members: Crawford, John.
Subjects: Environmental Health; Environmental Justice; Public Health
Keywords: Brownfields, Risk Communication
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30.
Gregg, Anne M.
Arsenic in drinking water: the public health implications of monitoring technologies.
Degree: MS, Public Health, 2007, Ohio State University
► In the 1970s many countries around the world reduced the incidences of…
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▼ In the 1970s many countries around the world reduced the incidences of waterborne disease by switching drinking water sources from bacterial laden surface waters to groundwater wells. In doing this, however, millions of people became exposed to arsenic (As) through drinking water. Over the years chronic exposure to arsenic has led to multiple serious health problems. A critical step toward assessing and limiting human exposure is to evaluate the concentration of arsenic. Field test kits provide a practical means for such evaluation; however, the reliability of field test kits has come into question. This project reviews the methods and technologies available for monitoring arsenic in drinking water. Third party performance data were used to evaluate the reliability of a representative subset of technologies from a public health perspective. Sensitivity, specificity, rates of false positives, and rates of false negatives were calculated, along with summarizing other data on linearity and ease of use characteristics. The technologies were evaluated according to a set of public health relevant criteria. The Merck Doubling Kit met or exceeded the most criteria. The evaluation provides some evidence that human health is being protected with the use of arsenic field test kits; however, there is room for improvement and a need for continuous efforts to lower the method detection limit to a health based level.
Advisors/Committee Members: Buckely, Timothy.
Subjects: Health Sciences, Public Health
Keywords: arsenic; drinking water; technology evaluation
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