OBJECTIVES: Breast Cancer (BC) is associated with a substantial economic burden; however, real-world data regarding this burden for the Colombian Health System is very scarce. This study aims to describe the economic burden borne by the Health System in patients with BC affiliated with the contributory regime, which provides healthcare services to almost half of Colombian population, in 2019.

METHODS: A cost-of-illness study was conducted from the perspective of the Health System that included all direct costs generated by prevalent cases of BC during 2019. First, the patients were identified through a validated electronic case-selection algorithm. Then, using an administrative database that contains patient level data on consumption of services included in the National Formulary (PBS, in Spanish Plan de Beneficios en Salud), all direct costs generated by delivering PBS services were extracted. Finally, using Propensity Score Matching and Ordinary Least Squares, the marginal costs of BC were calculated. Costs of services not included in the PBS (non-PBS) were calculated using aggregated data from MIPRES database. All attributable costs were calculated as the product of marginal costs and the expected number of cases. All costs were expressed in 2019 international dollars

RESULTS: A total of 46,148 patients with BC were identified. Total attributable costs were $395,676,053, 60% caused by consumption of non-PBS services. Marginal costs were $8,574 (95% Confidence Interval $8,546 - $8,602), with substantial variations between regions and age groups (from $4,547 for older patients in the Amazonia region to $12,940 for younger patients in the Pacific region). The costs for PBS services were higher for ambulatory services and for patients who died during 2020.

CONCLUSIONS: BC imposes a substantial economic burden for the Colombian Health System with important variations across regions and age groups. Near death patients suffering from BC and ambulatory services were associated with higher costs in PBS services.