Background Achieving optimal asthma control is the primary objective of asthma management. However, despite the existence of effective treatments, many patients experience periods of sub-optimal asthma control. The objective of this study was to quantify and project the future economic and health burden of sub-optimal asthma control in Canada.

Methods A probabilistic time-in-state model of asthma was created with inputs from published studies on the prevalence of asthma, levels of asthma control, and the impact of asthma control on costs and quality of life. In the primary analysis, we modeled the 20-year total direct costs (in 2014 Canadian dollars) and quality-adjusted life years (QALYs) from 2014 to 2033 in Canada. In the secondary analysis, we also incorporated indirect costs.

Results The undiscounted projected 20-year direct costs and QALYs lost attributable to sub-optimal asthma control were $24.40 billion and 1.82 million, respectively, from 2014 to 2033. The corresponding discounted values (at 3%) were $18.84 billion and 1.38 million. When indirect costs were considered, the total undiscounted and discounted costs of sub-optimal control were projected to be $280.49 billion, and $213.10 billion, respectively. A 10% reduction in prevalence of uncontrolled asthma was associated with 18% reduction in the economic and health burden of asthma over this time period.

Discussion : Sub-optimal asthma control is associated with a substantial economic and health burden. Given that with evidence-based disease management asthma can be controlled in the majority of patients, strategies towards improving asthma management can be associated with a significant return on investment.