Coronary heart disease (CHD) is the single largest cause of death in Australia. Lack of physical activity is a primary risk factor for CHD. The thesis aimed to quantify the efficacy of walking in reducing CHD risk. Meta-analyses were performed for the quantification with the application of random-effect meta-regression models. The thesis also aimed to quantify reductions in CHD-related direct healthcare costs, productivity loss and disease burden resulting from walking interventions in Australia, using the population attributable fraction model, the work and leisure models, and the consumer surplus model. Economic evaluations were also conducted to estimate CHD-related productivity loss using the human capital and the friction methods. The results indicated that 30 minutes of normal walking a day for 5-7 days a week compared to physical inactivity reduced CHD risk by 24%. There existed a dose-response relationship between walking and CHD risk reduction. An increment of approximately 30 minutes of normal walking a day for 5 days a week reduced CHD risk by 19%. The annual productivity loss resulting from CHD was estimated at AU$1.79 billion based on the human capital method and AU$25.05 million under the friction method. 30 minutes of normal walking a day for 5-7 days a week by the country???s ???sufficient??? walking population was shown to generate an estimated $126.73 million in net direct healthcare savings annually. The net economic savings could increase to AU$419.9 million if the whole inactive population engaged in ???sufficient??? walking. The study also found that 30 minutes of normal walking a day for 5-7 days a week reduced the burden of CHD by an estimated 25,065 DALYs and the productivity loss by AU$162.65 million annually under the leisure model. If the whole inactive population engaged in such walking, the total disease burden and productivity loss could be reduced by approximately one third. The findings present epidemiological and economic evidence in support of the national physical activity guidelines, which encourage the general public to engage in moderate physical activity including walking for a minimum of 30 minutes a day for 5-7 days a week.

Having a heart healthy lifestyle at a younger age is beneficial in reducing the risk of coronary heart disease (CHD) in adulthood and various health education programs for CHD prevention exist to persuade young adults to adopt a heart healthy lifestyle. Little is known, however, about the influence of watching live open heart surgery on young adults' adoption of a heart healthy lifestyle. To address that gap in knowledge, this study was conducted at a health facility in Virginia where students came to observe live open heart surgery. The purpose of the study was to understand whether watching live open heart surgery can influence young adults' attitudes and behaviors towards adopting a heart healthy lifestyle. The theory of health belief model and the theory of reasoned action were used in guiding this research. A quantitative design involving observation and administration of surveys was used. A survey with questions about participants' lifestyle practices was administered prior to observation of open heart surgery and 3 or more months afterwards. A total number of 179 young adults at baseline were considered eligible for the study. Ages of the research participants were between 18 and 35 years old. The t test and ANOVA results showed no significant differences between baseline and follow up data with regards to changes in behaviors of young adult students towards adopting a heart healthy lifestyle. The study concluded that observing live heart surgery did not significantly change behaviors of the students in adopting a heart healthy lifestyle. In order to achieve the desired changes in attitudes and behavior of students, looking into other evidence based options and pursuing those that can influence and motivate young adult students to adopt a heart healthy lifestyle can be a positive social change.