Projection of Body Mass Index (BMI), Chronic Conditions and Healthcare Costs in Canada: An Application of Microsimulation

Abstract

Obesity among Canadians is an important public health issue given health risks and economic impact. A micro-simulation model was developed to project health outcomes and healthcare costs of potential public health strategies to reduce obesity levels. The Population Health Model is a microsimulation model, which ages populations representative of Canada, one individual at a time, until death. Multivariate regression equations were estimated from the longitudinal National Population Health Survey to simulate plausible dynamics of BMI, chronic conditions, and death. Per capita annual direct healthcare costs by BMI, sex and age categories were estimated by combining resource use (from Statistics Canada national health surveys) and unit costs (from Canadian Institute for Health Information). Simulated per capita total cost for 2012 are higher for obese ($2,283) than for overweight ($1,726), underweight ($1,298) and normal weight ($1,284) categories. Prevalence of heart disease, diabetes and hypertension are respectively projected to be 5.2%, 6.6% and 18.2% in 2020 under the baseline scenario. However, 2020 prevalence would be lowered to 5.0%, 6.0% and 17.1% if BMI trajectories were instantly reduced by 5% (by means such as better nutrition, higher physical activity) from 2012 onwards. 2020 direct healthcare costs would be reduced by 2.7% (relative to costs without BMI reduction). The potential beneficial impact of reducing obesity in the Canadian population is evaluated quantitatively through micro-simulation modeling.