Thesis (M. S.)--Texas A&M University, 2004. / "Major Subject: Epidemiology" Title from author supplied metadata (automated record created on Nov. , 09:45:50.) Vita. Abstract. Includes bibliographical references.

Thesis (M.A. in National Security Affairs (Defense Decision Making & Planning))--Naval Postgraduate School, June 2007. / Thesis Advisor(s): Peter R. Lavoy, Anne Clunan. "June 2007." Includes bibliographical references (p. 111-117). Also available in print.

The claim has been made that psychological factors may contribute to the etiology of cancer. This thesis presents an examination of the difficulties of providing adequate evidence to support this claim from psychological studies of cancer patients. Although it has been reported that cancer patients differ psychologically from others, there is little agreement as to how they differ and little evidence that any observed differences are significantly associated with cancer. Moreover, were that association to be shown, there would still be nothing in it of any known etiological importance. The literature cannot preclude the view that the results so far obtained are merely by-products of faulty design and methods. Two studies are reported here on the basis of this view. The first study tests an alternative explanation of results reported by Le Shan and Worthington. They identified cancer patients correctly from a mixed group (cancer and non-cancer) on the basis of three personality characteristics found from responses to a projective test. It is hypothesised here that direct clues available from responses to this projective test would suffice for the identification of cancer patients without the aid of personality characteristics. Some support is provided for this hypothesis but the results of the study are inconclusive. In the second study it was possible to show statistically significant differences between answers of cancer patients and non-cancer subjects (peptic ulcer patients and healthy persons) to a simple personality questionnaire. Further analysis of results shows no difference betweenanswers of cancer patients and. peptic ulcer patients and no psychological characteristics common to a majority of cancer patients. This study demonstrates that statistical manipulation can provide spurious evidence for the existence of differences between cancer and non-cancer subjects which has little psychological significance. It is concluded that with psychological techniques now available it would be difficult to establish a correlation between personality and cancer. Also, with the present inadequacy of personality theory it is impossible to describe personality characteristics in physiological terms, and certainly not ones which could be linked with somatic dysfunction. For these reasons it is argued that psychosomatic research should be concerned with psychosomatic processes. Specific diseases can only be described as psychosomatic when these basic processes are better understood or if psychological treatment is helpful in removing or at least significantly relieving symptoms.

In previous epidemiologic studies, poor physical function has been associated with increased risks of nursing home placement, hospitalization, and mortality in older adults. However, these associations are subject to confounding and misclassification. Studies to date do not adequately account for these biases; previous studies have evaluated only cross-sectional associations, followed participants for less than ten years, or inadequately controlled for confounders by using only baseline values of characteristics that vary over time.5,75,106 In addition, no study has finely controlled for age, the strongest predictor of both physical function and health outcomes such as mortality and institutionalization in older adults. This dissertation is comprised of three studies that evaluated the associations between physical performance and skeletal health, respectively, with mortality and long-term nursing home residence while utilizing age-based risk set sampling, evaluating mediation by osteoporotic fractures, and controlling for death as a competing risk. All studies in this dissertation use data from the Study of Osteoporotic Fractures, a longitudinal epidemiologic study of older women with over 20 years of follow-up. Study 1 evaluated the association between physical performance and incident disability, using time-dependent exposures and confounders, and age-based risk sets to control for age. Women with poorer performance based on individual measures of physical function had an increased risk of incident disability over follow-up. Similarly, a whole body summary physical performance score was linearly associated with increased risk of death. Study 2 evaluates the association between low bone mineral density and mortality. Women with low bone mineral density were more likely to experience a fracture and to die compared to women with normal bone mineral density. Mediation analyses suggested that incident fracture had a measureable impact on this association, though this varied by fracture site. Study 3 evaluates the association between slow gait speed and risk of long-term nursing home placement while controlling for death as a competing risk. Women with slow gait speed had an increased risk of long-term nursing home residence, which was slightly attenuated when considering death as a competing risk. These results extend previous studies of the health effects of physical function among older women. The findings underscore the clinical importance of physical function and bone mineral density (BMD) for identifying older adults for whom interventions to improve their physical function may prolong their independence and optimize health.

RATIONALE: A low cost point of care test (POCT) to diagnose hepatitis C virus (HCV) viremia could be a critical step toward HCV elimination. The aim of this study is to inform the limit of detection (LOD) for an affordable POC test. METHODS: This study analyzed a convenience sample of cross-sectional HCV testing data from reference laboratories and clinical research studies in 9 countries. Participants of all ages with quantified HCV viremia were included. We analyzed the distribution of HCV viral load for the first detectable HCV RNA available, and derived the clinical sensitivity for a POCT with an LOD of 3 log IU/mL. Bivariate and multivariate analyses were then performed to identify demographic and clinical characteristics associated with low-level viremia (< 3 log IU/mL). RESULTS: The dataset included 53,295 participants from Cambodia, Canada, Cameroon, Georgia, Indonesia, Malaysia, Pakistan, Thailand, and Vietnam. Log HCV RNA was normally distributed, and ≥ 3 log IU/mL corresponded with clinical sensitivity of 98%. Neither HIV co-infection nor cirrhosis were significantly associated with low-level viremia, whereas bivariate analyses showed increased odds of 2.47 (95% CI 2.04, 2.99) for low-level HCV RNA among those ≤ 30 years old compared to those > 30, and an OR of 1.17 (1.02, 1.34) among females compared to males. Stepwise multivariate regression found no significant confounding. CONCLUSION: In this global dataset, a POCT with a LOD of 3 log IU/mL would identify 98% of chronic HCV infections. The increase OR among those ≤ 30 years old year olds is likely explained by a greater frequency among younger persons of recent infection, where fluctuating viremia is well described. A POCT for HCV that could identify persons with 3 log IU/mL or greater would likely facilitate affordable product development and expand the reach of HCV testing in resource-limited settings. / 2019-03-17T00:00:00Z

<p> <b>Introduction:</b> During 2017, approximately 750,000 strokes occurred, of those approximately 140,000 people died from a stroke and &lt;10% were also diagnosed with a hospital acquired condition. The economic burden associated with stroke care exceeds $34 billion; and hospitalizations with a hospital acquired condition increase costs. In the United States, differences in health outcomes have been documented; however, these studies show that sociodemographic differences continue to exist. The objectives of this study are to assess differences in clinical outcomes among the study population, and to assess if there are differences hospital charges. </p><p> <b>Methods:</b> To investigate differences in outcomes and hospital charges among the study population, the 2001-2011 Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database was used. Hospitalizations that occurred with a primary diagnosis of an ischemic stroke and a subsequent diagnosis of a hospital acquired condition were queried using ICD-9 codes. Additionally, the Elixhauser comorbidity index was used to identify comorbid conditions among individuals hospitalized. To assess the differences in outcomes and hospital charges chi-square, logistic regression, and hierarchical multilevel modeling procedures were used. All statistical analyses were performed using SAS 9.4. </p><p> <b>Results:</b> The overall death rate has decreased among the study population; however, racial/ethnic differences exist in patient outcomes. When assessing hospital charges, hospitalizations that occurred in the Southern region of the United States were higher than hospitalizations that occurred in the Northwest region of the United States. </p><p> <b>Conclusion:</b> Further analysis needs to be conducted to assess sociodemographic differences in clinical outcomes among the study population. There is a need to continue to identify sociodemographic groups with risks of mortality to better guide the funding opportunities to target these resources to populations that experience the worse health outcomes. Future studies should also assess the role of mental health, cultural competency, and care coordination to improve patient outcomes.</p><p>

<p> <b>Background.</b> Prostate cancer is the most common non-cutaneous cancer and the second leading cause of death among men in the United States. It highlights one of the highest racial disparities in health outcomes across cancers, with Non-Hispanic Black (NHB) men being at a 1.6 times higher risk of being diagnosed and 2.5 times higher risk of dying from the disease compared to Non-Hispanic White (NHW). Stage at diagnosis is the major metric used for prostate cancer prognosis, and assesses the extent of the disease. Prostate cancer development and progression is a multifactorial phenomenon, influenced by factors ranging from biological interactions to nativity. Therefore, we aimed at describing the characteristics of prostate cancer cases in New York State, and conduct an exploratory analysis to determine among the factors commonly associated with prostate cancer development and progression, which sociodemographic determinants contributed to racial disparities in stage at diagnosis of prostate cancer in New York State. To do this, we accessed the New York State Cancer Registry (NYSCR). </p><p> <b>Methods.</b> Prostate cancer cases recorded in the NYSCR from 2004 to 2014 constituted our sample. The NYSCR report prostate cancer stage in both the American Joint Committee on Cancer (AJCC) Tumor Node Metastasis (TNM) classification system and the National Cancer Institute Surveillance Epidemiology and End Results Program (SEER) summary staging 2000. For this study, the SEER Program summary staging 2000 was used. We created mutually exclusive categories for each covariate (grade at diagnosis, race, age at diagnosis, insurance status, marital status and nativity), while accounting for the sociodemographic landscape of New York State. Descriptive statistics, univariate and multivariable logistic regression models were computed, adjusting for grade at diagnosis, race, age at diagnosis, insurance status, marital status, and nativity. The variables found to have more than 10% missing data were removed and the data reanalyzed, to see the influence of data quality on our results. The Hosmer-Lemeshow test was used to assess the goodness of fit of each model. </p><p> <b>Results.</b> The sample consisted of 164,765 cases with a mean age of 66.72 &plusmn; 9.79 years. The greatest proportion of cases was diagnosed as local or regional stage prostate cancer. Statistically significant associations with stage at diagnosis in both the adjusted and unadjusted models were found with grades 3 and 4, NHB, Hispanics, patients aged 65-74, 75-84 and more than 85 years old, Medicaid and Medicare insured patients, patients with no insurance, patients with unspecified/other insurance, patients not married, patients with unknown marital status and patients of whom nativity status was unknown. The association between insurance status and distant stage at diagnosis was statistically significant for patients with military insurance in the unadjusted model, but not after adjustment. Birthplace information was missing for 42.53% of our sample. After birthplace was removed from the model and the data reanalyzed, the association for military insurance became statistically significant, while the association for unknown marital status became non-statistically significant. </p><p> <b>Conclusion.</b> Within this population-based sample of New York State prostate cancer cases, stage at diagnosis was found to be associated with grade, race, age at diagnosis, insurance status, and marital status. The multiplicity of factors associated with distant stage at diagnosis confirms the multifactorial nature of disparities in prostate cancer outcomes. The high percentage of missing data precluded the accurate assessment of the role of nativity. However, the factors identified here to act on racial disparities in stage at diagnosis in New York State provide a solid foundation for future analysis.</p><p>

<p> Objective: To investigate the impact of the density of foreign born Asian population on geographical incidence rate of liver cancer in New York City during 2009 &ndash; 2013 in order to find specific geographic areas in NYC where liver cancer intervention should be targeted. Method: We chose to employ cross-sectional and ecologic study design. We collected count data for liver cancer cases and sociodemographic characteristics from the 2010 U.S. census tracts (n = 2120) and health indicators from the United Hospital Funded neighborhoods (n = 34) in New York City during 2009 &ndash; 2013. We performed multilevel analysis in order to investigate the association between the density of foreign born Asian population and geographical incidence rate of liver cancer, controlling for sociodemographic characteristics at the census tract level and health indicators at the UHF neighborhood level. Result: We found that for each one-percentage increase in the foreign born East Asian population in a census tract region, there is a significant increase in the expected incidence rate of liver cancer by 1.0%, controlling for other variables. Conclusion: There was significant impact of the density of foreign born East Asian population on geographical incidence rate of liver cancer in NYC. We expected that the UHF neighborhoods with relatively high density of foreign born East Asian population and high liver cancer incidence rate should be targeted for the public health intervention of liver cancer.</p><p>

Physical activity guidelines encouraging activity among healthy pregnant women have been issued by the Centers for Disease Control and Prevention, yet Latina women remain more sedentary than non-Latina white women. Latina women are also at higher risk for gestational diabetes mellitus and, among Latina women, Puerto Rican women have the highest rates of low birth weight and preterm-related infant death. This dissertation utilized data from the Latina GDM study, a prospective cohort study of 1,231 Latina women recruited early in pregnancy and followed through delivery. Participants were interviewed in early and mid pregnancy for assessment of sociodemographics, acculturation, medical, and behavioral factors, in addition to administration of the Kaiser Physical Activity Survey for assessment of physical activity and sedentary behaviors. Birth outcomes were abstracted from medical records following delivery. In the first chapter, we assessed the prevalence of three health behaviors (meeting physical activity guidelines, meeting fruit/vegetable consumption guidelines, and cigarette smoking) in early and mid pregnancy and identified multiple factors associated with meeting health behavior guidelines in pregnancy. In the second chapter, we examined participation in sedentary behaviors, such as time spent TV watching, sitting at work, and low levels of sports and exercise, in pre, early and mid pregnancy in relation to maternal glucose intolerance and gestational diabetes mellitus. In the final chapter, we analyzed four types of physical activity (sports/exercise, household/caregiving, occupational, and active transportation) as well as total activity in relation to risk of preterm birth and small-for-gestational age. Findings represent the first study of physical activity and maternal/fetal outcomes conducted exclusively among Latina women, a group largely understudied in epidemiologic research. Results will guide culturally specific intervention programs in this high risk population.

Hypertensive disorders of pregnancy affect approximately 8% of pregnancies, and can lead to serious complications for both mother and child. While Latinas are at two-fold increased risk of preeclampsia relative to non-Latina white women, little research on hypertension in pregnancy has been conducted in this population. Furthermore, there are few modifiable risk factors for hypertensive pregnancy. Therefore, we examined associations between psychosocial stress, physical activity, and pre-pregnancy BMI and gestational weight gain and hypertensive disorders of pregnancy using data from the Latina GDM Study, a prospective cohort study of 1,231 women. The first study evaluated the association between perceived stress in early pregnancy and hypertensive disorders of pregnancy. Prior studies suggest an increased risk of hypertensive pregnancy associated with high levels of work-related stress, however there is no previous research evaluating the impact of general psychosocial stress. Psychosocial stress was measured in early pregnancy through the Perceived Stress Scale and hypertensive disorders of pregnancy were confirmed through obstetrician review of medical records. Using multivariable logistic regression we found no statistically significant association between early pregnancy stress and hypertensive pregnancy. The second study focused on the association between pre- and early pregnancy physical activity and hypertensive pregnancy. While some prior literature suggests that pre- and early pregnancy physical activity may be inversely associated with hypertensive pregnancy, findings are not conclusive. Pre- and early pregnancy physical activity was quantified using the Kaiser Physical Activity Survey, administered early in pregnancy. In this study, there was no statistically significant association between pre-pregnancy physical activity and hypertensive pregnancy. However, early pregnancy physical activity (total and household/caregiving) was inversely associated with risk of gestational hypertension. Finally, we examined the associations between pre-pregnancy BMI and gestational weight gain and hypertensive pregnancy. Previous studies in this area have included few Latinas. We found an increase in risk of hypertensive disorders with increased pre-pregnancy BMI and gestational weight gain exceeding the current Institute of Medicine guidelines for weight gain in pregnancy. These findings extend prior research to a Latina population. In summary, this dissertation research adds to the limited research on modifiable risk factors for hypertensive disorders of pregnancy.