The aim of this retrospective study is to evaluate adherence, switch and costs a year after the start of treatment with different erythropoietin-stimulating agents. There were 277 patients, 200 were originators (72.20%) and 77 (27.80%) were biosimilars. Adherence to treatment for originators is 0.84 ± 0.22 versus 0.76 ± 0.27 for biosimilars (p = 0.3241). Medication adherence was calculated as ratio between received daily dose to prescribed daily dose. The optimum value is 1, values less than 1 indicate loss of adherence. The cost of treatment per year is €7365 per patient for the use of the originator drug versus €2587 for biosimilars, with a difference of €4777 per patient.
Keywords: CIA; ESAs; PDD; RDD; biosimilars; chemotherapy-induced anemia; cost per prescribed daily dose; cost-saving; drug-used study; erythropoietin-stimulating agents; medication adherence; real-word data; received daily dose.