The cost of obesity in Canada

Background: Almost one-third of adult Canadians are at increased risk of di sability, disease and premature death because of being obese. In order to a llocate limited health care resources rationally, it is necessary to elucid ate the economic burden of obesity. Objective: To estimate the direct costs related to the treatment of and res earch into obesity in Canada in 1997. Methods: The prevalence of obesity (body mass index of 27 or greater) in Ca nada was determined using data from the National Population Health Survey, 1994-1995. Ten comorbidities of obesity were identified from the medical li terature. A population attributable fraction (PAF) was calculated for each comorbidity with data from large cohort studies to determine the extent to which each comorbidity and its management costs were attributable to obesit y. The direct cost of each comorbidity was determined using data from the C anadian Institute of Health Information (for direct expenditure categories) and from Health Canada (for the proportion of expenditure category attribu table to the comorbidity). This prevalence-based approach identified the di rect costs of hospital care, physician services, services of other health p rofessionals, drugs, other health care and health research. For each comorb idity, the cost attributable to obesity was determined by multiplying the P AF by the total direct cost of the comorbidity. The overall impact of obesi ty was estimated as the sum of the PAF-weighted costs of treating the comor bidities. A sensitivity analysis was completed on both the estimated costs and the PAFs. Results: The total direct cost of obesity in Canada in 1997 was estimated t o be over $1.8 billion, This corresponded to 2.4% of the total health care expenditures for all diseases in Canada in 1997. The sensitivity analysis r evealed that the total cost could be as high as $3.5 billion or as low as $ 829.4 million; this corresponded to 4.6% and 1.1% respectively of the total health care expenditures in 1997. When the contributions of the comorbidit ies to the total cost were considered, the 3 largest contributors were hype rtension ($656.6 million), type 2 diabetes mellitus ($423.2 million) and co ronary artery disease ($346.0 million). Interpretation: A considerable proportion of health care dollars is devoted to the treatment and management of obesity-related comorbidities in Canada . Further research into the therapeutic benefits and cost-effectiveness of management strategies for obesity is required. It is anticipated that the p revention and treatment of obesity will have major positive effects on the overall cost of health care.