INTRODUCTION: Epidemiological transition theory, first postulated by Omran in 1971, provides a useful framework for understanding cause-specific mortality changes and may contribute usefully to predictions about cause-specific mortality. However, understandings of mortality transitions and associated epidemiological changes remain poorly defined for public health practitioners due to lack of evidence from low- and middle-income countries. Therefore, understanding of the concept and development of epidemiological transition theory as well as population burden of premature mortality attributable to risk factors is needed. OBJECTIVES: This thesis aims to understand how epidemiological transition theory has been applied in different contexts, using available evidence on mortality transitions from high, middle- and low- income countries, as well as the contribution of risk factors to mortality transitions, particularly for premature mortality. METHODS: A Medline literature search from 1971 to 2013 was conducted to synthesise published evidence on mortality transition (paper I). A descriptive analysis of trends in cause of death using INDEPTH data was conducted, focusing on specific causes of death in 12 INDEPTH sites in Africa and Asia, using the INDEPTH 2013 standard population structure for appropriate comparisons across sites (paper II). A retrospective dynamic cohort database was constructed from Swedish population registers for the age range 30-69 years during 1991-2006, to measure reductions in premature non-communicable disease mortality using a life table method (paper III). Prospective cohort data from Västerbotten Intervention Programme from 1990 to 2006 were used to measure the magnitude of premature non-communicable disease mortality reductions associated with risk factor changes for each period of time (paper IV). FINDINGS: There were changes in emphasis in research on epidemiological transition over the four decades from 1971 to 2013, from cause of death to wide-ranging aspects of the determinants of mortality with increasing research interests in low-and middle-income countries, with some unconsidered aspects of social determinants contributing to deviations from classic theoretical pathways. Mortality rates declined in most sites, with the annual reductions in premature adult mortality varied across INDEPTH sites, Sweden, which now is at late stage of epidemiological transition stage, achieved a 25% reduction in premature mortality during 1991-2006. Overall downward trends in risk factors have helped to reduce premature mortality in the population of Västerbotten County, but some benefits were offset by other increasing risks. The largest mortality changes accrued from reductions in smoking, hypertension and hypercholesterolaemia. CONCLUSIONS: This thesis established patterns of current epidemiological transition in high, middle-and low-income countries (Asia and Africa), where the theory fits the transition patterns in some countries, but with some needs for further adjustments in other settings, as well as deviations from the classical ET theory in the last four decades. It highlights the need to identify the burden of mortality and morbidity, particularly for reducing mortality occurring before the age of 70 years and its attribution to risk factors, which are a major public health challenge. This informs shifting of public health priorities and resources towards prevention and control of chronic non-communicable disease risk factors.

Background and objective: Researchers have been looking for a way to predict future emission rates, and come up with explanations on how to tackle the issue of global warming through changes in individual behavior for decades. The focus of these studies have, on the other hand, focused more on nutritional bases rather than cultural. This study’s objective is to provide a method, as a useful tool in further analysis on GHG-emission based on cultural behavioral factors such as socio-economic status as well as age, sex, etc. with diet as emission prediction factor. This could be a stepping stone toward future research on Co2e related to e.g. physiological factors such as BMI, blood pressure and diseases. Method: With the use of data obtained from the FFQ questionnaire within the VIP-program, combined with estimates of greenhouse gas-emission (Co2e) attributed to specific diets obtained from Röös, estimations of individual Co2e emission-levels were calculated using the software “R”. The dataset contained 159 687 observations and 152 different variables. The data was obtained from the Department of Public Health and Clinical Medicine at Umeå University. Portions sizes were mainly collected from the Swedish Food Composition Database. Box-plots and regression analysis were made to illustrate the main findings. Result: The result was a new dataset that could be applied to any population to estimate Co2e-emission on individual level based on an FFQ, given that the FFQ have the same structure as the one in the VIP. The variables that contributed to the highest amount of Co2e were animal products i.e. butter, milk and meat. Chicken, pork and fish were not nearly as Co2e heavy as the meat products containing beef such as “steak”, “minced meat” and “hamburgers”. The regression analysis showed that higher age had a positive effect on reducing emission, as well as being a woman. Education showed an increase in Co2e for higher education. There were some small differences among municipalities. Marital status gave a slight decrease in the regression, meaning married couples emits more than singles. Exercise showed an increase in Co2e for active individuals in the regression analysis. However, the most noticeable result were sex, yielding a relatively big decrease in Co2e-emission for women compared to men. Conclusion: People at younger ages, within the observed age groups 40-60, seemed to reduce their carbon footprint more in relation to the higher age groups over the last 20 years. Overall, the general diet-based carbon footprint in Västerbotten seems to have increased slightly during the last 17 years. A remarkable dip were noticed in 2003, however this might not have been due to any behavioral changes, since the trend broke in 2006 and instantly receded back to the normal levels. This study confirms the fact that meat and dairy products are responsible for a significant amount of the diet-based emission. This topic needs to be studied more, and with this method of applying GHG-emission measures to individual diet-based data, a gate has been opened for a new field of research.

Background: Diabetes is a common and costly disease that is expected to continue even to grow in prevalence and health expenditures over the coming decades. Type 2 diabetes is the most common diabetes type and is characterized by insulin resistance and relative insulin deficiency. Type 2 diabetes develops over a long period and is often undetected over years. During this time, people almost always first develop any of the pre-diabetic states, i.e. impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or a combination of both (IFG&IGT). This thesis focuses on type 2 diabetes only. In the following, the term diabetes is used to refer to type 2 diabetes only. Diabetes is associated with a sedentary lifestyle and obesity. While those are not the only factors contributing to the development and maintenance of diabetes, several studies have shown that prevention of diabetes among individuals at high risk through lifestyle change is possible, effective and cost-effective, especially targeting diet and exercise to reduce weight. No previous study had, however, estimated the cost-effectiveness of diabetes prevention strategies from a population-based perspective including healthy individuals and also considered IFG and IGT as two distinct pre-diabetic states. Objective: The overall objective of this thesis was to establish, describe and evaluate a model that can assess the cost-effectiveness of lifestyle intervention programs to prevent diabetes. Methods: First, a Markov Model was established using data from the literature. The cost of a German diabetes prevention program was estimated. Second, risk equations for change to worsened glucose states were estimated using factor analysis and logistic regression based on consecutive data from the Västerbotten Intervention Program (VIP). The risk equations described transition probabilities in the final model and were based on several risk factors such as age, sex, physical activity and smoking status. Third, information on the Short-Form 36 questionnaire from the VIP population was transformed into Short-Form 6D. Health utility weights (HUW) by glucose group and four risk factors were estimated using beta regression. Fourth, an updated Markov model was established using an updated model structure compared to the one in Paper I, program costs of Paper I, risk equations of Paper II, health utility weights of Paper III and updated cost and mortality estimates. Results: The first model in Paper I showed that lifestyle intervention programs have the potential to be cost-effective with a high degree of uncertainty. The risk equations in Paper II indicated that the impact of each risk factor depended on the starting and ending pre-diabetes state, where high levels of triglyceride, hypertension, and high body mass index were the strongest risk factors to transit to a worsened glucose state. The overall mean HUW in Paper III was 0.764 with healthy individuals having the highest HUW, those with diabetes the lowest and those in pre-diabetic states ranging in between. The intervention described in Paper IV was cost-effective for all sex and age scenarios ranging from 3,833 EUR/QALY gained (women, 30 years) to 9,215 EUR/QALY gained (men, 70 years). The probability that the intervention is cost-effective was high (85.0-91.1%). Conclusion: We established a model that can estimate the cost-effectiveness of different scenarios of initiatives to prevent diabetes. The prevention or the delay of the onset of diabetes is feasible and cost-effective. A small investment in a healthy lifestyle with the change in physical activity and diet together with weight loss can have a decent, cost-effective result. The full range of possibilities this model offers has not been evaluated so far. We have, however, shown that implementing a lifestyle intervention program like the Västerbotten Intervention Programme would be cost-effective.