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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Impact of Migration and Spatial Patterns on Filariasis Infections in Dreikikir District, East Sepik Province of Papua New Guinea

Bun, Krufinta 2011 (has links)
No description available.

Environmental and genetic factors in lung cancer : epidemiological and biomolecular studies focusing on nonsmokers

Nyberg, Fredrik 1998 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. Härtill 7 uppsatser.

Characteristics of Death Certificate Only Cases in the Cancer Registry

Garrett, Amy 29 December 2014 (has links)
No description available.

Development of a lung cancer prediction model for surgeons and factors affecting its national application

Deppen, Stephen Andrew 4 August 2013 (has links)
Lung cancer is deadly, killing more people than breast, colon and prostate cancer combined. Surgeons evaluating patients for lung cancer face a dilemma: to operate and subject the individual to operation associated mortality and morbidity or not operate and possibly miss early diagnosis and treatment. No models designed for surgeons evaluating lung lesions. We successfully estimated the TREAT model. A model designed for surgeons with an internally validated AUC of 0.87 and Brier score of 13. If the TREAT model is applied to a national population, its accuracy may decrease due to local conditions. To determine the possible extent of such variation, benign disease prevalence after lung surgery was estimated using 2009 Medicare hospital discharge data. Significant variation in benign disease prevalence between states was observed with a low of 1.3% in Vermont and a high of 25% in Hawaii. The causes for this observed variation are unknown. Residence in a county with high fungal lung disease prevalence was not associated with increased likelihood of benign disease. FDG-PET scan variance was observed in the national ACOGOS Z4031 trial. FDG-PET sensitivity (82%) and specificity (31%) were significantly lower than in previous published studies. Granuloma occurred in 68% of the false positive FDG-PET scans and sensitivity varied significantly between sites. Scan accuracy increased with increasing lung lesion size. Whether the observed variation is caused by practice variation, referral patterns, fungal lung disease, or other factors is unknown. A meta-analysis examined FDG-PET accuracy to diagnose lung lesions sought to determine if other researchers had observed variance in FDG-PET accuracy. Seven studies reported false positive scans arising from granulomas caused by infectious lung disease. Specificity of those studies was 59%, significantly lower than the specificity (77%) observed in the remaining 53 studies. Studies whose mean lesion size was less than or equal to 20 mm had significantly lower sensitivity than studies conducted in larger lesions. The TREAT model shows clinical promise and should be externally validated. The causes of observed variation in benign disease prevalence and FDG-PET accuracy should be investigated with particular attention made to measuring infectious disease exposures that cause granulomas.

Statistical methods for analyzing epidemiological data

Lau, Ho-yin, Eric 2005 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2006. Title proper from title frame. Also available in printed format.


Xu, Xiaohui 25 September 2007 (has links)
The environment plays an important role in the health of communities. However, few health systems exist at the state and/or local levels to efficiently track the potential health effects associated with environmental exposure. The objectives of this dissertation are 1) to use secondary data for assessing the possible associations between health outcomes and environmental exposure and/or hazard; 2) to explore possible methods of data linkage and analyses which can be used by state and local environmental health tracking agencies and 3) to bring positive contributions to the development of national Environmental Public Health Tracking Network (EPHT). In this project, the Three Mile Island (TMI) cohort data (1979-1995) and Pennsylvania (PA) Cancer registry data were used to evaluate the associations between cigarette smoking and adult leukemia. A case-crossover analysis was performed with PA cardiopulmonary hospital admission data and local air pollution data to assess the health effects of air pollutants on cardiopulmonary disease before and after the elimination of a major point source of air pollution. A case-control study was also conducted to examine the associations between term low birth weight and particulate air pollution. The results showed that cigarette smoking could increase the risk of acute myeloid leukemia (AML). In addition, particulate air pollution is significantly associated with cardiovascular hospitalization and low birth weight in term infant. In conclusion, the findings suggest that environmental hazards have adverse health effects on a number of health endpoints. Secondary data can be a great resource for environmental public health tracking, which is of public health relevance. The use of existing data is an effective way to assess the potential health effects associated with environmental exposures after an appropriate study design with a feasible data linkage and correct methods of data analyses was developed.


Venkitachalam, Lakshmi 25 September 2007 (has links)
Cardiovascular disease remains the leading cause of mortality and morbidity in the 21st century accounting for about one-fifth of deaths overall each year in the United States. Percutaneous coronary intervention (PCI), used initially in the 1970s, is now the most commonly performed non-surgical procedure for atherosclerotic coronary disease. PCI, in the last three decades, witnessed rapid advancements, both technologically (from balloons to stents and atherectomy devices) as well as in adjunct therapy (antithrombotics, fibrinolytics and antiplatelet agents). The purpose of this dissertation, designed as three research papers, was to capture this evolution and the associated impact on clinical and patient-reported outcomes, in the prospective, multicenter NHLBI-sponsored 1985-86 PTCA (era of balloon angioplasty) and 1997-2004 Dynamic (era of stents, brachytherapy and drug-eluting stents) registries. Temporal trends in clinical practice revealed the heterogeneity in patients (and lesions) undergoing PCI and yet, consistent dramatic improvements were seen in procedural success with reduced need for repeat procedures; little impact was observed in one-year mortality rates. In the Dynamic Registry, significant reductions in one year prevalence and risk of patient-reported angina were observed concurrent to use of new evidence-based secondary pharmacological therapy. In contemporary practice, women and patients with prior/repeat PCI continued to be at high-risk for post-procedural symptoms. Supplemental therapy, following initial PCI, was more often pharmacological with concomitant reduction in bypass surgery and repeat PCI. On average, patient-reported quality of life improved over time and was influenced by both symptom status and the need and type of supplemental therapy. Indeed, these findings reflect the dynamic nature of PCI with an increasingly heterogeneous treatment population and yet favorable procedural outcomes (procedural success, reduced repeat procedures, greater relief of symptoms). More importantly, they highlight the continued lack of impact on mortality and identify symptom-prone subsets in contemporary practice. This time-sensitive documentation is especially fitting given the 300% increase in the number of PCIs since its initial use. From a public health point of view, any treatment modality applied in this magnitude warrants constant surveillance, more so with the emerging safety concerns, and this underscores the importance of well-designed registries.

Growth Hormone Genes and Prostate Cancer Risk

Dressen, Amy S 25 September 2007 (has links)
Background: Growth hormone (GH) SNPs are associated with breast cancer and colon cancer. The author investigated the association of prostate cancer with genetic polymorphisms in GH SNPs in the Ancillary MrOS study. Methods: Included in the current investigation were 128 men with prostate cancer and 743 healthy men, 65 years of age or older. SNPs were tested in Growth Hormone 1 (GH1, n=4), Growth Hormone Receptors (GHR, n=15), Growth Hormone-Releasing Hormone (GHRH, n=4), Growth Hormone-Releasing Hormone Receptors (GHRHR, n=10), Ghrelin (GHRL, n=8), and Growth Hormone Secretagogue Receptor (GHSR, n=9) genes for an association with prostate cancer risk. SNPs were selected based on HapMap Phase 1 and based on functional variation. The SNPs were genotyped using Illumina Assay and were included if the minor allele frequency was 1% or greater. Logistic regression analysis was used to examine associations, adjusted for age, weight, BMI, truncal % fat, total % fat, and diabetes. Similarly, tests of trends and tests of dominant/recessive effect were performed. Results: After adjusting for potential confounding factors, two GH1 SNPs, one GHR SNP, one GHRH SNP, two GHRHR SNPs, one GHRL SNP, and one GHSR SNP showed significant associations with prostate cancer risk. Public Health Significance: If the relationships observed in this study are confirmed, it would justify the investigation of approaches that would reduce the activity of GH in those at high risk for prostate cancer. Conclusions: The results of the current study suggest that GH SNPs are associated with prostate cancer risk. This provides support for replication of these findings in other studies.


Buchanich, Jeanine M 27 September 2007 (has links)
Public Health Significance: The objective of this study is to establish a clinical decision-making rule for mild head injury in young children, an extremely common type of injury seen in emergency departments. These children appear to respond differently to mild head injuries and face different developmental issues than do older children and management guidelines remain unclear. Methods: Subjects were 97 children less than three years old with mild head injury (ICD9 codes 800-804 and 850-854) and an initial Glasgow Coma Scale score of 14 or 15, consecutively evaluated at a Level 1 Pediatric Emergency Department. Demographic, injury, symptom and treatment characteristics were abstracted from the medical records. A classification and regression tree (CART) program was used to identify characteristics that were correlated with intracranial injury (ICI) among children in the study. The information garnered from the tree was used to construct a clinical decision-making rule for the evaluation of very young children with mild head injuries. A cost analysis was done to determine potential cost savings from the new decision-making rule. Results: Forty-six percent of the children were less than 12 months, 24% were 12-23 months and 30% were 24-35 months old at the time of injury. Three-quarters of all injuries occurred from falls. Almost 25% of the children had evidence of an ICI on the CT scan; more than two-thirds of the ICIs occurred in children less than 12 months old (p=0.03). We examined multiple CART models to assess the impact of different misclassification penalties and missing data. The main parent node on the final CART model was the presence of vision changes; splits also occurred with the presence of scalp lacerations, vomiting, the child being inconsolable, sex and area of residence. Minor changes in the way children without ICIs are treated could result in cost savings as much as $90,000 per year. Conclusion: While similarity exists between decision-making rules for older children and that found for this cohort, very young children have unique characteristics that merit further study and may require a separate decision-making process.

Temporal and Spatial Analysis of Cancer Rates in the United States

Han, Yueh-Ying 28 September 2007 (has links)
Introduction: Spatial, temporal and racial patterns of cancer remain largely unexplained in the United States. Time trends of cancer incidence and mortality can be used to estimate the current cancer burden, anticipate clinical care needs, and suggest hypotheses regarding possible etiologic explanations for underlying trends. Methods: Using U.S. 1979-2003 cancer incidence and 1969-2003 cancer mortality data, age-period-cohort and Joinpoint regression models were fit to summarize gender- and race-specific temporal trends for three broad cancer categories that include tobacco-related cancer, screen-detectable cancer, and cancer unrelated to tobacco and screening. Demographic patterns and time trends of non-Hodgkins lymphoma (NHL) incidence between Pennsylvania and the U.S. from 1985 to 2004 were compared. Using Idaho cancer incidence, 1990-2005, and arsenic levels in ground water, 1990-2005, spatial analysis was conducted to identify geographic patterns of cancer incidence and to evaluate the relationship between arsenic exposure in ground water and cancer incidence in Idaho. Results: Over the last three decades, tobacco-related cancer incidence declined among men and increased among women. Screen-detectable cancer incidence increased, more rapidly among men than women. For cancer unrelated to tobacco and screening, incidence increased in every gender-and-race group. Though not identical, NHL incidence patterns, with substantial increases, were similar in the U.S. and Pennsylvania. NHL incidence was higher in Pennsylvania counties with a greater percentage of urban residents. Although spatial clustering was demonstrated in Idaho cancer incidence, no relationship was found between arsenic exposure in ground water and Idaho cancer incidence. Conclusion: NHL and other cancers unrelated to smoking or screening have increased in the U.S. in the past two decades in white and black men and women. Etiologic research should attempt to identify modifiable risk factors, including environmental exposures, responsible for the increasing incidence of NHL and cancer unrelated to tobacco and screening. The ecologic association observed in Pennsylvania between NHL incidence and urban residence may be relevant to NHL risk in the entire United States. Additional environmental and demographic information should be evaluated in order to clarify the arsenic-related cancer risk in Idaho counties where ground water has been found to contain higher levels of arsenic. Public Health Significance: Age, period and cohort modeling of cancer incidence and mortality provides important indications of current and future health care needs and also suggests hypotheses for future research. The results of this analysis provide health professionals, researchers, and policy-makers with detailed information and an understandable overview of cancer patterns in the United States. Hypotheses should be generated about these unexplained patterns of cancer so that avoidable cancer risks can be identified that will decrease the cancer burden and associated requirements for health care.

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