Browsing by Subject "Risk Factors"
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Item Dementia and Mild Cognitive Impairment: Epidemiologic Research of Risk Factors(2019-07) George, KristenDementia and mild cognitive impairment (MCI) are often caused by progressive and irreversible pathologic brain changes. Alzheimer’s disease, cerebrovascular disease, and Lewy body-related diseases are the most common causes with many individuals having mixed etiologies. Characterizing risk factors for dementia and MCI is complex due to overlapping etiologies, long latency periods, and the influence of cognitive reserve. While major risk factors including advanced age, hypertension, and the ApoE4 allele have been identified, further investigation of early- and mid-life risk factors is needed. Using data from the Atherosclerosis Risk in Communities (ARIC) Neurocognitive Study, we examined prospectively risk factors for dementia and MCI. In the first manuscript, we assessed the association between life course socioeconomic status (LC-SES) and dementia and MCI. Low individual-level LC-SES was associated with an increased risk of dementia. Low individual-level economic factors of LC-SES (e.g. income, home ownership) were associated with increased risk of dementia independent of educational attainment. However, neighborhood-level LC-SES was not associated with risk of dementia or MCI. The second manuscript assessed the association between thyroid dysfunction (measured via autoimmune thyroid disease (AITD) and thyroid hormone levels) and risk of dementia and MCI. We found no association between AITD and dementia and MCI. Subclinical hypothyroidism was associated with a lower risk of dementia while overt hyperthyroidism, particularly with very elevated serum FT4 hormone levels, was associated with an increased risk of dementia compared to euthyroid participants. The third manuscript examined the association between lifetime history of migraine symptoms and risk of dementia and MCI. Despite published evidence of brain abnormalities in migraineurs, which might lead to cognitive impairment, we found no association between migraine and dementia and MCI. This dissertation extends our understanding of risk factors for cognitive impairment underscoring the importance of early- and mid-life exposures on late-life risk of dementia and MCI.Item Disentangling over-representation of parents with disabilities in the child welfare system: Exploring child maltreatment risk factors of parents with disabilities(Children and Youth Services Review, 2014-12) Lightfoot, Elizabeth; Slayter, ElspethThe study explores the risk factors for child maltreatment and self-reported child maltreatment among a population-based sample of parents with disabilities. Drawing on a nationally-representative, population-based data file that oversampled people of color, income-adjusted odds ratio tests were conducted to establish population differences among parents with and without limitations in activities of daily living (ADLs). Results suggest that parents with disabilities were more likely to report many of the risk factors associated with child maltreatment than parents without disabilities, including witnessing interpersonal violence as a child; experiencing violence, neglect or a foster care stay as a child; mood or substance use disorders; and engaging in or receiving interpersonal violence as an adult. Before controlling for income, parents with disabilities had only a negligibly higher rate of engaging in violence against their children. After controlling for income, parents with disabilities were 2.5 times more likely to engage in violence against their children. Parents with disabilities who did engage in violence against their children had greater amounts of some of the child maltreatment risk factors in comparison to parents with disabilities who did not engage in violence, particularly their own childhood experiences of maltreatment, witnessing of interpersonal violence as a child, childhood stays in foster care, and experiences with interpersonal violence as an adult. Findings add to the understanding of the risk factors for child maltreatment that are related to the collateral effects of having a disability, and through the use of income-adjusted data, help disentangle why parents with disabilities are over-represented in the child welfare system. The findings highlight the need for the child welfare system to increase its disability competence in working with both children and parents with disabilities.Item Epidemiological investigation of bovine tuberculosis outbreaks in Uruguay (2011-2013)(2016-05) Picasso Risso, CatalinaBovine tuberculosis (BTB) is a chronic disease of cattle caused by infection with the Mycobacterium bovis, and with an important zoonotic potential. Countries have widely recognized BTB as a major animal and public health problem. Uruguay is a South American country with a strong agriculture-based tradition and economy. Uruguay was one of the pioneers in the fight against BTB in the world in the late 1800’s, with continuously update of BTB-control measures, especially in dairy herds, which resulted in the design of the current national BTB control program. Under the current BTB control program, surveillance is based on test-and-slaughter strategies for dairy farms, and abattoir carcasses inspection looking for tubercles in all slaughtered cattle. When a farm is reported as positive, control measures include movement restrictions, testing of neighboring farms, and traceback of all animal movements performed up to two years previous to the outbreak. As a consequence of this surveillance program, BTB prevalence in Uruguay has been traditionally low (<11 outbreaks per year). However, between 2011 and 2013, the incidence of BTB increased, concerning farmers, industry, veterinarians, and the government authorities. The goal of this study was to assess the spatial dynamics of BTB in Uruguay in the 2011-2013 period, and the association between BTB and demographic and movement factors in the Uruguayan dairy industry. Data provided by the Uruguayan Ministry of Livestock, Agriculture, and Fisheries included information on geolocation, BTB status (positive/negative), and onset date. Also, individual information on movements from/to all farms during the 2008 to 2013 period in Uruguay was provided to obtain farm-level network characteristics. Fifteen, 26, and 16 BTB-outbreaks were reported in 42,759 (2011), 43,213 (2012), and 42,186 (2013) susceptible farms, respectively. The spatial distribution of incident outbreaks was assessed using the Cuzick-and-Edwards’ test, and the Bernoulli model of the spatial scan statistic. Significant (P=0.05) clustering at the second order of neighborhood was detected in 2012, and significant high-risk clusters were identified in southwestern (2011, 2012, 2013), northwestern (2012), and southeastern (2012) Uruguay. The presence of spatial aggregation in southwestern Uruguay (consistently in 2011 and 2012, and corresponding to a dairy production land-use) suggests an association between land management and BTB risk. Global clustering detected in 2012 suggests dissemination by close contact of BTB. The increase of BTB incidence in disparate regions of the country suggests that live animal movements may have played a role in spreading the disease. A subset of the dairy Uruguayan farms was assessed with a conditional multivariate logistic regression model to investigate the risk factors most likely associated with BTB, with three controls (n=171) per positive farm (n=57), accounting for spatial dependency. Ten demographic, and 51 movement epidemiological factors were evaluated as possible risk factors. The final model included large herds, high number of incoming cattle to the farm (>44 cattle), and purchasing steers as factors increasing the odds of BTB. The first two factors were in agreement with previous studies, highlighting the importance of control in terms of disease spread this practice in the cattle industry. The association between BTB incidence and purchasing steers may be associated with certain management practices for which this covariate may serve as a proxy. Results from this study were presented to and discussed with Uruguayan Animal Health Bureau members to address applicability of results. These results and discussions contributed to the design and implementation of disease management strategies intended to enhance the effectiveness of BTB control programs in Uruguay, with the ultimate objective of preventing or mitigating the impact of the disease in the human and animal populations of the country.Item Moral Injury: A Statewide Assessment on the Burden, Risk, and Protective Factors in Minnesota Firefighters(2022-07) DeMoulin, DouglasIntroductionThe construct of moral injury is relatively new, primarily studied in trauma-exposed military personnel, and measurement scales recently available to screen symptoms of moral injury. However, no scale exists for firefighters; consequently, resulting in limited data for the risk and protective factors of moral injury in firefighters. Firefighters are considered one of the most stressful occupations, responding to critical incidents involving personal threat or harm to self, a violation of core beliefs about the world, and witnessing pain and suffering of others. Exposures to a single traumatic event or cumulative traumatic events can result in posttraumatic stress disorder (PTSD), depression, suicide ideation and possibly risk for moral injury. The objective of this study aims to address the gap in available instruments by developing a moral injury scale for firefighters and assess the potential risk and protective factors of moral injury in firefighters. MethodsA multi-phased study was conducted using qualitative methods to modify an established moral injury scale used in veterans by employing the Delphi method paired with cognitive interviewing with firefighters, and quantitative methods testing the psychometric properties. A cross-sectional study was conducted using dual-frame sampling methods to recruit Minnesota firefighters statewide assessing the association between moral injury and perceived stress towards traumatic calls, perception of being trained to cope with mental health of firefighting, and moral injury comorbidity with PTSD, depression, and suicide ideation. This study assessed the use of department debriefs and department resources (chaplains, critical incident stress management “CISM”, city employee assistance programs “CEAP”, and department employee assistance programs “DEAP”) and the protective effects for moral injury in trauma-exposed firefighters. ResultsPsychometric properties of the EMIS-F are comparable to the original military scale. The internal consistency of the EMIS-F was excellent (ω=0.94), inter-item correlations showed evidence of EMIS-F measuring a unidimensional construct (ρ=.30-.72). Multivariable analyses identified the risk factors for change in mean moral injury risk scores, which were firefighters self-reporting high perceived stress levels of calls involving fatalities (β=7.7) and children (β=3.1), and strongly disagreeing that they were trained to cope with mental health of firefighting (β=9.9). Firefighters with two or more mental health comorbidities showed over a 16.0 increase in mean moral injury risk scores, and greatly influenced by PTSD comorbidity. The protective factors of moral injury among firefighters self-reporting their most traumatic experience was those that used department debriefs and found them helpful, chaplains, and DEAP. Firefighters who found debriefs unhelpful showed evidence of debriefs as a risk factor for moral injury, in addition to using CEAP and CISM. Stigma showed evidence as a potential effect modifier regarding the impact or use of debriefs and increased moral injury risk scores. ConclusionThis study provides a reliable and valid moral injury scale that can be applied in research, clinical, and fire organization settings to screen symptoms of moral injury in firefighters. Knowledge of specific risk and protective factors presented not only serve for interventions, but an opportunity to evaluate and improve existing practices to enhance the well-being of firefighters.Item Multidisciplinary Investigation Of Rural Intersection-Related Crashes And Crash Injuries: Characteristics, Risk Factors And Prevention(2021-06) Tian, DisiIntroduction: Rural intersections disproportionally contribute to crashes in rural United States (U.S.). Few available studies have examined potential causal associations between important intersection-relevant exposures and crash outcomes. Additionally, the efficacy of an advanced Rural Intersection Conflict Warning System (RICWSs), implemented at high-risk rural two-way stop-controlled intersections, has been largely unknown. Methods: This multidisciplinary study included: 1) an ecological epidemiologic analysis to identify the magnitude of and risk factors for rural intersection-related crash rates (per 100 million Annual Average Daily Traffic — AADT) by the level of injury severity, among various intersection characteristics; 2) a quasi-experimental epidemiologic investigation to evaluate the efficacy of the RICWSs for crash reductions, among 56 intersection risk-sets, each containing one RICWS treatment and three relevant control intersections; and 3) a driving simulator study to evaluate how different RICWS designs impacted drivers’ behaviors among 120 participants. The study population involved a representative sample of rural intersections in Minnesota (n = 4,172). Adjusted crash rate-ratios were obtained from the Generalized Estimating Equations (GEE), while adjusting for relevant confounders. Potential causal associations between RICWSs and various crash rate outcomes (per intersection per year) were determined, using Difference-in-Difference (DID) and Difference-in-Difference-in-Difference (Triple-D) analytical methods. Various regression models, applying the GEE, enabled efficacy determination of each RICWS design and an aggregated RICWS treatment effect, averaged across all simulated RICWS designs, among different levels of drivers' ages, mainstream traffic volume, and intersection visibility. Results: Rural intersection-related crash rates were significantly associated with various important intersection relevant risk factors by the level of injury severity. Minnesota RICWSs demonstrated a potential significant protective effect against targeted right-angle crashes, continuously, over time, post-treatment (p < 0.05). The original RICWS design potentially improved gap acceptance performance among drivers; however, it also increased the risk of stop-sign violations (Risk Ratio = 2.2, 95% Confidence Interval (CI) = 1.03 to 4.64). Conclusions: This study serves as a basis to provide insight into prioritizing the prevention of rural intersection-related crashes and associated injuries. It has significant research relevance to mitigate the overall mortality and morbidity of motorists, including the working population, on the U.S. rural roads.Item Parenting Resilience in the Context of Homelessness: Risk and Protective Factors(2015-08) McCormick, ChristopherHomelessness among families with children has become a surprisingly common and persistent problem. Children who experience the disruptions of homelessness are at increased risk for difficulties with academic, social, emotional, and behavioral development. Decades of research on resilience suggests that effective parenting helps to mitigate the effects of adversity on child development. However, relatively little is known about factors that predict parenting quality during family homelessness. This study examined predictors of parenting quality among 138 families who were staying in three Minneapolis emergency housing shelters, with the goal of identifying distal and proximal influences on parenting in families facing homelessness. Based on transactional-ecological systems perspectives on the determinants of parenting, and research on risk and protective processes for parenting under stress, current parenting in a shelter context was expected to relate to recent and past adversity of the parent and current health and social resources. Current trauma, anxiety, and depressive symptoms in parents were expected to interfere with effective parenting. Two basic dimensions of parenting, warmth and structure, were expected to underlie observed parenting assessed by three empirically validated observational coding techniques. Factor analyses indicated two dimensions of parenting; however, these reflected a blend of warmth/structure and a distinct factor of negativity. Thus, subsequent analyses predicted parenting on each of these two dimensions, using linear methods of path analysis and multiple regression to test for predictive, mediating, and moderating effects of earlier and recent adversity, physical and mental health, and available resources on parenting quality. Also tested was the moderating influence of resources, specifically cognitive resources and social support, on the relationship between adversity, mental health, and parenting quality. Finally, a person-centered analytic approach was used to provide an integrated portrait of resilient parenting in the context of homelessness. Controlling for parent age, sex, and child behavior, parents’ adverse experiences in childhood were positive related to warmth/structure, contrary to expectations, whereas current resources, as predicted, were positively and independently associated with this aspect of effective parenting. Resources did not moderate any of these relationships. Parents classified as showing resilience in the person-focused analyses had greater cognitive, social, and emotional resources than parents classified as maladaptive. Strengths and limitations of this study are discussed in relation to future research and the goals of identifying malleable protective influences on parenting for families in challenging situations.Item Prediction of incident Type 2 diabetes: modifiable and non-modifiable risk factors among high-risk populations and diverse racial/ethnic groups(2010-07) Bower, Julie KristenNearly ten percent of adults in the U.S. aged twenty years and older live with type 2 diabetes. Improving risk stratification and prediction facilitates the identification of those most likely to develop diabetes and informs prevention efforts. The aim of this dissertation was to evaluate the predictive validity of established definitions of high risk across population subgroups, and to examine the impact of modifiable and non-modifiable factors that predict type 2 diabetes risk, presented in three related manuscripts. In the first manuscript, the predictive validity of fasting glucose and glycated hemoglobin A1c (HbA1c) measures were evaluated in the Multi-Ethnic Study of Atherosclerosis (MESA), a community-based observational cohort study that enrolled 6,814 Caucasian Americans, Chinese Americans, African Americans, and Hispanic Americans aged 45-84 years. The association between fasting glucose levels at baseline and cumulative incidence of diabetes did not differ by self-reported ethnic group. However, the strength of association between HbA1c and diabetes incidence differed significantly by ethnicity. The second manuscript examined predictors of incident diabetes among individuals with pre-diabetes in the Coronary Artery Risk Development in Young Adults (CARDIA) study, a community-based longitudinal observational study of 5,115 African Americans and Caucasian Americans aged 18-30 years at baseline. Body mass index was the strongest predictor of diabetes; other predictors included race/ethnicity, diastolic blood pressure, and HDL-cholesterol. A final manuscript explored interactions between single nucleotide polymorphisms (SNPs), the trait of cardiorespiratory fitness, and diabetes-related outcomes in the CARDIA cohort. SNPs of rs8050136 of the fat mass and obesity associated (FTO) gene and rs3856806 of the peroxisome proliferator-activated receptor gamma (PPARG) gene were associated with HbA1c levels; the association between cardiorespiratory fitness level and HbA1c differed by genotype of rs8050136 in Caucasians and rs3856806 in African Americans. This dissertation evaluated the predictive value of current screening tools and markers of risk for type 2 diabetes. Improving diabetes prevention in population subgroups that are disproportionately affected -- particularly those with pre-diabetes and in certain race/ethnic groups -- is dependent upon effective screening tools validated across populations, and a more comprehensive understanding of the role of modifiable and non-modifiable risk factors in influencing one's diabetes risk profile.Item Risk Factors for Breast Cancer among American Indian Women(2016-12) Nadeau, MelanieObjective: This study was designed to identify risk factors associated with breast cancer among American Indian women, as the first step for developing a risk prediction model similar to the Gail model established for non-Hispanic white women. Methods: A case-control study design was undertaken. Cases and controls were selected from among women undergoing mammograms at the Quentin N. Burdick Medical Care Facility (Indian Health Service) in Belcourt ND. For each woman with breast cancer (n=141), two controls were selected when possible (n=278). All women completed a breast cancer risk questionnaire at the time of their mammogram. This questionnaire was the primary source of data, supplemented by electronic and medical chart files. The risk factors examined were those included in the Gail model, including woman’s age, age at first live birth, age of menarche, the number of previous benign breast biopsies, and the total number of first-degree relatives with breast cancer. In addition, body mass index and parity were also collected. Odds ratios and 95% confidence intervals were calculated using logistic regression. Results: I did not find an association for American Indian women in North Dakota between most of the risk factors commonly identified in other populations and breast cancer. The majority of the associations were weakly positive with confidence intervals including the null value. Of all the risk factors examined, nulliparity was the only one that consistently showed a positive significant association. Conclusion: Disparities in breast cancer incidence, mortality and screening among Northern Plains American Indians emphasize the need to better understand the risk factors associated with breast cancer in this population. It is my hope that this study will contribute to the development of a National Cancer Institute Breast Cancer Risk Assessment Tool that reflects the risk of breast cancer among American Indian women. Based on the results of my study, the value of risk prediction models in American Indian communities is uncertain and clinicians should be cautious in using the current Gail Breast Cancer Risk Assessment Tool to inform their American Indian patients of their risk for breast cancer.Item Venous thromboembolism: Lifetime risk and novel risk factors(2015-03) Bell, Elizabeth JeanDeep vein thrombosis and pulmonary embolism are viewed as different manifestations of the same disease process, termed venous thromboembolism (VTE). VTE represents a significant source of mortality and morbidity. The first two manuscripts of this dissertation use data from two large, prospective cohort studies: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) study. We followed participants, aged 45-64 years in ARIC and >=65 in CHS at baseline (1987-89 in ARIC, 1989-90 and 1992-C93 in CHS), for incident VTE (through 2011 and 2001 in ARIC and CHS, respectively). In manuscript 1, we estimated the lifetime risk and 95% confidence interval of incident VTE, using data from CHS and ARIC. We used a modified Kaplan-Meier method, accounting for the competing risk of death. We calculated that 1 in 12 middle-aged adults develop VTE in their lifetime. This estimate of lifetime risk may be useful to promote awareness of VTE and guide decisions at both clinical and policy levels. Manuscripts 2 and 3 aimed to identify and clarify novel risk factors for VTE. The etiology of VTE is not fully understood, especially in contrast to atherothrombosis. Further identification of VTE risk factors may yield pathophysiological insights into the disease that could eventually provide new prevention or treatment options. In manuscript 2, we quantified the association between orthostatic hypotension (OH) at baseline and VTE, using data from ARIC and CHS. In CHS, there was a positive association between incident VTE and OH (Hazard ratio for total VTE = 1.74 (95% confidence interval: 1.20-2.51)). In contrast, there was no association between OH and VTE in ARIC. In conclusion, community-dwelling older adults with OH have a moderately increased risk of VTE. These results were not replicated in a population-based middle-aged cohort. In manuscript 3, we conducted a systematic review and meta-analysis to quantify the association between diabetes and VTE. We identified 19 eligible studies. The pooled relative risk for the association of diabetes with VTE was 1.10 (95% confidence interval: 0.94-1.29). This literature-based systematic review and meta-analysis supports either no association or a very modest positive one between diabetes and VTE in the general population. Diabetes is unlikely to play a major role in VTE development.