Cancer drug expenditure in British Columbia and Saskatchewan: a trend analysis

Expenditure on systemic therapy for cancer has been increasing quickly owing to population growth, increased use, both in the number of users and in prescription volume, and rising drug prices. Our objective was to describe trends in expenditure in British Columbia and Saskatchewan's cancer care systems and to elucidate these drivers of growth.

In this trend analysis, we obtained pharmacy dispensing records from the BC Cancer and Saskatchewan Cancer Agency pharmacies for all anticancer therapies dispensed in 2006-2013. We calculated total annual expenditure directly from the data and conducted a trend analysis of crude and standardized annual expenditure using generalized linear models. We estimated trends in the following components of total expenditure: cancer incidence, number of systemic therapy users per incident case, number of dispensed prescriptions per user and cost per prescription. Analysis was stratified by patient age group, cancer site and route of administration (oral or intravenous/other).

Expenditure on systemic therapies, adjusted for population growth and aging, increased an average of 9.2% (95% confidence interval [CI] 7.2 to 11.2) per year in Saskatchewan and 6.4% (95% CI 5.3 to 7.6) per year in BC. Growth in expenditure on orally administered agents was more than 2 times higher than growth in expenditure on intravenous/other agents. Growth rates varied significantly by cancer site. In both provinces, rising cost per prescription was the largest contributor to overall growth.

Price is the primary driver of growth in systemic therapy expenditure in both BC and Saskatchewan. Understanding the mechanisms of expenditure growth may inform system planning and support policy-makers' efforts to manage rising costs.