Background: A sedentary lifestyle diminishes quality of life (QOL) and contributes to increasing prevalence of obesity, diabetes and cardiovascular diseases (CVD), and thus increases the economic burden on health care and society. Expensive and tightly controlled lifestyle interventions reduce cardiovascular risk and onset of diabetes. Transferring these findings to the primary care setting is of clinical importance. The primary aim of this thesis was to apply a lifestyle intervention program in the primary care setting among individuals with moderate-to-high risk for CVD, and evaluate the effects on physical activity, cardiovascular risk factor levels and QOL. A secondary aim was to investigate the cost-effectiveness. Methods: A randomized controlled trial with one intervention group (n=75) and one control group (n=76) with follow-up at 3, 12, 24 and 36 months was used. Patients with the diagnosis obesity, hypertension, dyslipidemia, type 2 diabetes or any combination thereof (mean age 54 yr, 57% female) were recruited from a primary health centre in northern Sweden. The three-month intervention period consisted of group-based supervised exercise sessions and diet counselling, followed by regular, but sparse, group meetings with a behavioural approach during three years. Clinical measurements included anthropometrics, aerobic fitness, blood pressure and metabolic traits. Questionnaires on self-reported physical activity, stages of change for physical activity, and QOL were used. In a cost-utility analysis the costs, gained quality-adjusted life years (QALY), and savings in health care were considered. Probability of cost-effectiveness was described using Net Monetary Benefit Method. Results: Overall, the lifestyle intervention generated beneficial improvements in anthropometrics, blood pressure, aerobic fitness and activity level, and QOL, compared to the control group which only received one information meeting.  At 36 months, intention-to-treat analyses showed that lifestyle modification reduced waist circumference (–2.2 cm), waist-hip ratio (–0.02), systolic blood pressure (–5.1 mmHg), and diastolic blood pressure (–1.6 mmHg) and significantly improved aerobic fitness (5%).  BMI, lipid or glucose values did not differ between groups. Progression to active stages of change for physical activity and increases in time spent exercising and total physical activity were reported. Both physical and mental dimensions of QOL were improved during the study period, but after 3 years differences persisted mainly in physical dimensions. Cost per gained QALY was low, 1668-4813 USD (savings not counted). Visits to family physicians significantly decreased and there was a net saving of 47 USD per participant. Probabilities of cost-effectiveness were 89-100% when 50 000 USD was used as threshold of willingness to pay for a gained QALY. Conclusions: A group-based lifestyle intervention program in a primary health care setting favourably influences cardiovascular risk-factor profiles, increases physical activity level, and improves several dimensions of QOL in high-risk individuals, at least up to 3 years. The intervention method was highly cost-effective in relation to standard care. The results emphasize the advantage of an intervention that combines supervised exercise with regular follow-ups for reaching long term effects.  The study high-lights the feasibility of lifestyle interventions in the primary care setting and the importance of health care professionals supporting change in lifestyle.

The initial treatment options for patients with stable coronary artery disease include optimal medical therapy alone, or coronary revascularization with optimal medical therapy. The most common revascularization modality is percutaneous coronary intervention (PCI) with either bare metal stents (BMS) or drug-eluting stents (DES). PCI is believed to reduce recurrent angina and thereby decrease the need for additional procedures compared to optimal medical therapy alone. It remains unclear if these benefits are sufficient to offset the increased costs and small increase in adverse events associated with PCI. The objectives of this thesis were to determine the degree of angina relief afforded by PCI and develop a tool to provide contemporary estimates of the impact of angina on quality of life. In addition, we sought to develop a comprehensive state-transition model, calibrated to real world costs and outcomes to compare the cost-effectiveness of initial medical therapy versus PCI with either BMS or DES in patients with stable coronary artery disease. ii We performed a systematic search and meta-analysis of the published literature. Although PCI was associated with an overall benefit on angina relief (odds ratio [OR] 1.69; 95% Confidence Interval [CI] 1.24-2.30), this benefit was largely attenuated in contemporary studies (OR 1.13; 95% CI 0.76-1.68). Our meta-regression analysis suggests that this observation was related to greater use of evidence-based medications in more recent trials. Using simple linear regression, we were able to create a mapping tool that could accurately estimate utility weights from data on the Seattle Angina Question, the most common descriptive quality of life instrument used in the cardiovascular literature. In our economic evaluation, we found that an initial strategy of PCI with a BMS was cost- effective compared to medical therapy, with an incremental cost-effectiveness ratio (ICER) of $13,271 per quality adjusted life year gained. In contrast, DES had a greater cost and lower survival than BMS and was therefore a dominated strategy.

The initial treatment options for patients with stable coronary artery disease include optimal medical therapy alone, or coronary revascularization with optimal medical therapy. The most common revascularization modality is percutaneous coronary intervention (PCI) with either bare metal stents (BMS) or drug-eluting stents (DES). PCI is believed to reduce recurrent angina and thereby decrease the need for additional procedures compared to optimal medical therapy alone. It remains unclear if these benefits are sufficient to offset the increased costs and small increase in adverse events associated with PCI. The objectives of this thesis were to determine the degree of angina relief afforded by PCI and develop a tool to provide contemporary estimates of the impact of angina on quality of life. In addition, we sought to develop a comprehensive state-transition model, calibrated to real world costs and outcomes to compare the cost-effectiveness of initial medical therapy versus PCI with either BMS or DES in patients with stable coronary artery disease. ii We performed a systematic search and meta-analysis of the published literature. Although PCI was associated with an overall benefit on angina relief (odds ratio [OR] 1.69; 95% Confidence Interval [CI] 1.24-2.30), this benefit was largely attenuated in contemporary studies (OR 1.13; 95% CI 0.76-1.68). Our meta-regression analysis suggests that this observation was related to greater use of evidence-based medications in more recent trials. Using simple linear regression, we were able to create a mapping tool that could accurately estimate utility weights from data on the Seattle Angina Question, the most common descriptive quality of life instrument used in the cardiovascular literature. In our economic evaluation, we found that an initial strategy of PCI with a BMS was cost- effective compared to medical therapy, with an incremental cost-effectiveness ratio (ICER) of $13,271 per quality adjusted life year gained. In contrast, DES had a greater cost and lower survival than BMS and was therefore a dominated strategy.