Search

Objectives As obesity-associated events impact long-term survival, health economic (HE) modelling is commonly applied, but modelling approaches are diverse. This research aimed to compare the events simulation and the HE outcomes produced by different obesity modelling approaches. Methods An external validation, using the Swedish obesity subjects (SOS) study, of three main structural event modelling approaches was performed: (1) continuous body mass index (BMI) approach; (2) risk equation approach; and (3) categorical BMI-related approach. Outcomes evaluated were mortality, cardiovascular events, and type 2 diabetes (T2D) for both the surgery and the control arms. Concordance between modelling results and the SOS study were investigated by different state-of-the-art measurements, and categorized by the grade of deviation observed (grades 1-4 expressing mild, moderate, severe, and very severe deviations). Furthermore, the costs per quality-adjusted life-year (QALY) gained of surgery versus controls were compared. Results Overall and by study arm, the risk equation approach presented the lowest average grade of deviation (overall grade 2.50; control arm 2.25; surgery arm 2.75), followed by the continuous BMI approach (overall 3.25; control 3.50; surgery 3.00) and by the categorial BMI approach (overall 3.63; control 3.50; surgery 3.75). Considering different confidence interval limits, the costs per QALY gained were fairly comparable between all structural approaches (ranging from 2,055 pound to 6,206 pound simulating a lifetime horizon). Conclusion None of the structural approaches provided perfect external event validation, although the risk equation approach showed the lowest overall deviations. The economic outcomes resulting from the three approaches were fairly comparable.

According to the World Health Organization, overweight and obesity are major risk factors for a number of chronic diseases, including cardiovascular diseases such as heart disease and stroke, which are the leading causes of death worldwide. This dissertation evaluates, replicates and validates the current structural modelling landscape in obesity, with an emphasis on commonly applied obesity-associated event simulation approaches. It aims to increase trust and confidence in the selection and interpretation of results related to specific methodological approaches commonly used as basis for health economic models in obesity. This research was able to identify some important aspects related to the health economic modelling methodology in general, and key aspects specifically related to the field of obesity. Besides highlighting and investigating the aspects related to research integrity of published health economic models, our research formed a basis for evaluating the strengths and weaknesses of different structural event simulation approaches. Furthermore, we defined valuable future areas of research to further enhance trust and confidence in health economic modelling, especially in the field of obesity.

Objective: To investigate the cost-utility of eprosartan versus enalapril (primary prevention) and versus nitrendipine (secondary prevention) on the basis of head-to-head evidence from randomized controlled trials. Methods: The HEALTH model (Health Economic Assessment of Life with Teveten® for Hypertension) is an object-oriented probabilistic Monte Carlo simulation model. It combines a Framingham-based risk calculation with a systolic blood pressure approach to estimate the relative risk reduction of cardiovascular and cerebrovascular events based on recent meta-analyses. In secondary prevention, an additional risk reduction is modeled for eprosartan according to the results of the MOSES study ("Morbidity and Mortality after Stroke - Eprosartan Compared to Nitrendipine for Secondary Prevention"). Costs and utilities were derived from published estimates considering European country-specific health-care payer perspectives. Results: Comparing eprosartan to enalapril in a primary prevention setting the mean costs per quality adjusted life year (QALY) gained were highest in Germany (24,036) followed by Belgium (17,863), the UK (16,364), Norway ( 13,834), Sweden ( 11,691) and Spain ( 7918). In a secondary prevention setting (eprosartan vs. nitrendipine) the highest costs per QALY gained have been observed in Germany (9136) followed by the UK (6008), Norway (1695), Sweden (907), Spain (-2054) and Belgium (-5767). Conclusions: Considering a 30,000 willingness-to-pay threshold per QALY gained, eprosartan is cost-effective as compared to enalapril in primary prevention (patients 50 years old and a systolic blood pressure 160 mm Hg) and cost-effective as compared to nitrendipine in secondary prevention (all investigated patients). © 2009, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).