Aims: The aims of this thesis were to investigate trends and ethnic disparities in the incidence and outcome of stroke in Auckland, New Zealand between 1981 and 2003. Methods: Trends were assessed using information from the three Auckland Regional Community Stroke (ARCOS) studies, conducted in people (aged ≥15 years) in Auckland, during 12-month calendar periods in 1981-1982, 1991-1992, and 2001-2002. These studies used comparable definitions and case finding methods and have been shown to meet the stringent criteria for a population-based “ideal” stroke incidence study. Rates were calculated using Poisson distribution and are presented with 95% confidence intervals. Trends in survival were assessed using Cox Proportional hazards regression modelling. Results: Overall trends in the incidence and event rates of stroke declined across the study period. These declines were significant in males and for the ages 65 to 74 years only. However, growing disparities in the rates of stroke between the major ethnic groups in New Zealand were found, with significant declines in New Zealand Europeans and increases in Māori and Pacific populations. Dramatic improvements in survival over the study period were also found, with the greatest improvement in the acute period, within the first 28-days after stroke. Adjustments for patient or disease severity factors strengthened the survival model. However, adjustments for care/service factors nullified the survival model, thus explaining most of the improving trend. Conclusions: The small declines in the incidence of stroke, improvements in survival and the ageing of the New Zealand population will lead to data dramatic increases in the number of people living with the effects of stroke. To maintain stable numbers of strokes occurring, more intensive prevention strategies need to target high-risk populations and population-wide health education strategies are needed to improve the health of the general population, hence reducing the risk of stroke. / Health Research Council (HRC) of New Zealand Pacific Health PhD scholarship

Aims: The aims of this thesis were to investigate trends and ethnic disparities in the incidence and outcome of stroke in Auckland, New Zealand between 1981 and 2003. Methods: Trends were assessed using information from the three Auckland Regional Community Stroke (ARCOS) studies, conducted in people (aged ≥15 years) in Auckland, during 12-month calendar periods in 1981-1982, 1991-1992, and 2001-2002. These studies used comparable definitions and case finding methods and have been shown to meet the stringent criteria for a population-based “ideal” stroke incidence study. Rates were calculated using Poisson distribution and are presented with 95% confidence intervals. Trends in survival were assessed using Cox Proportional hazards regression modelling. Results: Overall trends in the incidence and event rates of stroke declined across the study period. These declines were significant in males and for the ages 65 to 74 years only. However, growing disparities in the rates of stroke between the major ethnic groups in New Zealand were found, with significant declines in New Zealand Europeans and increases in Māori and Pacific populations. Dramatic improvements in survival over the study period were also found, with the greatest improvement in the acute period, within the first 28-days after stroke. Adjustments for patient or disease severity factors strengthened the survival model. However, adjustments for care/service factors nullified the survival model, thus explaining most of the improving trend. Conclusions: The small declines in the incidence of stroke, improvements in survival and the ageing of the New Zealand population will lead to data dramatic increases in the number of people living with the effects of stroke. To maintain stable numbers of strokes occurring, more intensive prevention strategies need to target high-risk populations and population-wide health education strategies are needed to improve the health of the general population, hence reducing the risk of stroke. / Health Research Council (HRC) of New Zealand Pacific Health PhD scholarship

Aims: The aims of this thesis were to investigate trends and ethnic disparities in the incidence and outcome of stroke in Auckland, New Zealand between 1981 and 2003. Methods: Trends were assessed using information from the three Auckland Regional Community Stroke (ARCOS) studies, conducted in people (aged ≥15 years) in Auckland, during 12-month calendar periods in 1981-1982, 1991-1992, and 2001-2002. These studies used comparable definitions and case finding methods and have been shown to meet the stringent criteria for a population-based “ideal” stroke incidence study. Rates were calculated using Poisson distribution and are presented with 95% confidence intervals. Trends in survival were assessed using Cox Proportional hazards regression modelling. Results: Overall trends in the incidence and event rates of stroke declined across the study period. These declines were significant in males and for the ages 65 to 74 years only. However, growing disparities in the rates of stroke between the major ethnic groups in New Zealand were found, with significant declines in New Zealand Europeans and increases in Māori and Pacific populations. Dramatic improvements in survival over the study period were also found, with the greatest improvement in the acute period, within the first 28-days after stroke. Adjustments for patient or disease severity factors strengthened the survival model. However, adjustments for care/service factors nullified the survival model, thus explaining most of the improving trend. Conclusions: The small declines in the incidence of stroke, improvements in survival and the ageing of the New Zealand population will lead to data dramatic increases in the number of people living with the effects of stroke. To maintain stable numbers of strokes occurring, more intensive prevention strategies need to target high-risk populations and population-wide health education strategies are needed to improve the health of the general population, hence reducing the risk of stroke. / Health Research Council (HRC) of New Zealand Pacific Health PhD scholarship

Venous thromboembolism (VTE), comprising deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common and preventable cause of morbidity among individuals and hospital in-patient mortality. Further, it imposes a substantial burden upon the community and its health care system and economy. Studies performed in Western societies suggest that the annual incidence of DVT is about 0.8 to 1.2 per 1,000, PE about 0.3 to 0.6 per 1,000, and VTE about 1.0 to 1.8 per 1,000. However, it is not known if these estimates can be generalised to the Australian population because of differences in ethnic composition and other risk factors for VTE among the different populations. In this thesis, I undertook a prospective, community-based cohort study over a 13-month period in 2003 – 2004 to determine the incidence and crude event rate of symptomatic, objectively verified VTE in north-east metropolitan Perth. The study population was broadly representative of the national Australian population in terms of age, sex and ethnic distribution. Cases were identified through multiple overlapping sources. The incidence of DVT, PE and VTE in the community were 0.52 (95% confidence interval, CI: 0.41 – 0.63), 0.31 (95% CI: 0.22 – 0.40) and 0.83 (95% CI: 0.69 – 0.97) per 1000 per year, respectively. The annual incidence of DVT, adjusted to the World Standard population, was 0.35 (95% CI: 0.26 – 0.44) per 1000, PE 0.21 (95% CI: 0.14 – 0.28) per 1000 and VTE 0.57 (95% CI: 0.47 – 0.67) per 1000. The crude event rate for VTE was 0.85 (95% CI: 0.71 – 0.99) per 1000 per year. These findings suggest that the incidence of DVT, PE and VTE are lower than in other Western societies studied. Possible reasons include a lower prevalence of exposure to causal risk factors (genetic and environmental) and incomplete case ascertainment. Knowledge of the local incidence and event rate allows health planners to allocate appropriate resources and evaluate cost-effective preventive measures.

Aims: The aims of this thesis were to investigate trends and ethnic disparities in the incidence and outcome of stroke in Auckland, New Zealand between 1981 and 2003. Methods: Trends were assessed using information from the three Auckland Regional Community Stroke (ARCOS) studies, conducted in people (aged ≥15 years) in Auckland, during 12-month calendar periods in 1981-1982, 1991-1992, and 2001-2002. These studies used comparable definitions and case finding methods and have been shown to meet the stringent criteria for a population-based “ideal” stroke incidence study. Rates were calculated using Poisson distribution and are presented with 95% confidence intervals. Trends in survival were assessed using Cox Proportional hazards regression modelling. Results: Overall trends in the incidence and event rates of stroke declined across the study period. These declines were significant in males and for the ages 65 to 74 years only. However, growing disparities in the rates of stroke between the major ethnic groups in New Zealand were found, with significant declines in New Zealand Europeans and increases in Māori and Pacific populations. Dramatic improvements in survival over the study period were also found, with the greatest improvement in the acute period, within the first 28-days after stroke. Adjustments for patient or disease severity factors strengthened the survival model. However, adjustments for care/service factors nullified the survival model, thus explaining most of the improving trend. Conclusions: The small declines in the incidence of stroke, improvements in survival and the ageing of the New Zealand population will lead to data dramatic increases in the number of people living with the effects of stroke. To maintain stable numbers of strokes occurring, more intensive prevention strategies need to target high-risk populations and population-wide health education strategies are needed to improve the health of the general population, hence reducing the risk of stroke. / Health Research Council (HRC) of New Zealand Pacific Health PhD scholarship

Thesis (Ph. D.) - University of Göttingen, 2004.

Thematic Paper (M.C.T.M. (Clinical Tropical Medicine))--Mahidol University, 2007. / LICL has E-Thesis 0024 ; please contact computer services. LIRV has E-Thesis 0024 ; please contact circulation services.

Thesis (Ph. D.)--University of Göttingen, 2004. / Description based on print version record.

The three essays of this dissertation inform tax policy design. It is a compilation of empirical and experimental research work. The first and the second essays explore the performance of a recent tax policy reform at the sub-national level in India in terms of revenue efficiency as well as economic efficiency. India is among the only three countries in the world to have adopted a sub-national VAT. Therefore, empirically examining its performance not only improves the understanding of this important tax policy reform but also informs tax policy decision-making at the sub-national level in other developing countries. India transitioned to the state-level VAT between the years 2003 and 2008. Among other things, it was expected to achieve revenue growth and decrease tax cascading on commodities by improving economic efficiency of the indirect tax system. In the first essay, I model the impact of the VAT on revenue by adding revenue dependent administrative and compliance costs associated with taxation to an existing model developed by Keen and Lockwood (2010). The theoretical results show that replacing one type of indirect tax with another improves long-run revenue efficiency only if there is a net decrease in the administrative, compliance and distortionary costs of taxation at the margin. I then compile a unique state-level dataset for the years 1990 to 2010 to determine changes in the long-run revenue efficiency from the use of the VAT. This essay contributes to the literature by extending an existing revenue efficiency model and testing it in the unique situation of India’s sub-national VAT. The results reveal a significant improvement in the long-run revenue efficiency of the sales tax instrument used by state governments. The model implies this improvement is driven by a net fall in the marginal taxation costs from the use of the state-level VAT. This finding has important implications on the role of a sub-national VAT in the future as an effective tax instrument in the developing countries. The second essay appeals to the general theory of tax incidence which suggests that a VAT will have less impact on prices than a traditional turnover tax because the VAT does not “get stuck” in the production process as a turnover tax does. The impact should be larger for goods that have more components to the production process as the tax then “touches” more of the final product. In this essay I measure the change in the level of tax cascading with VAT by using multiple waves of the state- and household-level expenditure surveys. Specifically I test the impact of the VAT on the real consumption of households on a variety of consumption goods. I find the biggest significant decrease in the tax cascading burden of the long-term durable goods which essentially involve the maximum production components. This result is found in the 18 more developed states of India which are the focus of the empirical analysis due to data constraints. The third essay is an experimental research which looks at the influence of institutions on the economic burden of an excise tax. The traditional long-run tax incidence theory establishes that the economic incidence of an excise tax is independent of the assignment of the liability to pay tax. However, the theory is silent on the possible effects of the market institutions on tax incidence. Since all markets need an institution to function and every market institution has its own unique price and quantity determination property, it is important to understand its bearings on the incidence of taxes. Existing experimental research has tested economic incidence under many different market institutions but no previous research systematically analyzes and compares the incidence of a unit tax under two important market institutions we deal with in everyday life. One of these institutions is posted offer which dominates the consumer goods markets in developed countries and the other is double auction which is frequently observed in developing countries. I report a significant impact of these market institutions on tax incidence. In particular, I find that consumers bear a much higher burden of a unit tax in the posted offer markets as compared to the double auction markets and their burden further increases when the liability to pay the tax is on the seller.

Made available in DSpace on 2014-10-09T12:44:44Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:51Z (GMT). No. of bitstreams: 1 07297.pdf: 2897384 bytes, checksum: ade16901adf7663b2eb89bed60b5b413 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo