The Patient Level Cost of Asthma in Adults in South Central Ontario

OBJECTIVE: To assess the annual cost of asthma per adult patient from the perspectives of society, the Ontario Ministry of Health and the patient.

DESIGN: Prospective cost of illness evaluation.

SETTING: Ambulatory out-patients residing in southern central Ontario.

POPULATION STUDIED: Nine hundred and forty patients with asthma over 15 years of age studied between May 1995 and April 1996.

OUTCOME MEASURES: Direct costs, such as respiratory-related visits to general/family practitioners, respiratory specialists, emergency rooms, hospital admissions, laboratory tests, prescription medications, dispensing fees, devices and out-of-pocket expenses, were calculated. Indirect costs, such as absences from work or usual activities, and travel and waiting time, were studied.

MAIN RESULTS: Unadjusted annual costs were $2,550 per patient. Hospitalizations and medications each accounted for 22% of the total cost and indirect costs 50% of the total costs. More severe disease, older age, smoking, drug plan availability and retirement were significant predictors of costs. Annual costs per patient varied from $1,255 (95% CI $1,061 to $1,485) in young nonsmokers with no drug plan and mild disease to $5,032 (95% CI $4,347 to $5,825) in older smokers with drug plans and severe disease. Clinically important reductions in the quality of life occurred with increasing severity.

CONCLUSIONS: Interventions aimed at reducing productivity losses, admissions to hospital and medication costs may result in savings to society, the provincial government and the patient. The quality of policy and allocation decisions may be enhanced by cost of illness estimates that are comprehensive, precise and incorporate multiple perspectives.