Nonchemotherapy drug-induced cytopenias: A cost-of-illness study using the microcosting methodology based on real-world data.

Aims: Our study aimed to determine the healthcare utilization and costs of nonchemotherapy drug-induced cytopenias and analyse the main drivers of costs.

Methods: This cost-of-illness study was conducted using the microcosting (bottom-up) approach based on real-world data. Data on the patients who developed leucopenia, anaemia or thrombocytopenia as nonchemotherapy drug-induced blood disorders were extracted from records of the inpatients treated in a tertiary care university hospital.

Results: The study included 46, 71 and 80 cases of leucopenia, anaemia and thrombocytopenia, respectively. Leucopenia had the highest costs per case (average: 200 928.4, median: 176 078.4 Serbian dinars [RSD], interquartile range: 171 223.4 RSD), followed by thrombocytopenia (average: 115 065.2, median: 89 732.4 RSD, interquartile range: 77 755.9 RSD) and anaemia (average: 109 502.5, median: 90 267.3 RSD, interquartile range: 74 225.1 RSD). These costs expressed as Gross Domestic Product per capita based on purchasing power parity were 6.97, 2.85 and 2.84% for leucopenia, anaemia and thrombocytopenia, respectively. In leucopenia, 48.9% of the costs were the costs of drugs, while in anaemia and thrombocytopenia, the majority of the costs were due to the length of hospitalization (38.6 and 34.7%, respectively). The factors with the greatest influence on the total costs of anaemia and thrombocytopenia were the length of hospitalization and the number of computed tomography scans, while the cost of leucopenia treatment was most influenced by survival status, age and the number of laboratory tests.

Conclusions: Our study showed that the use of healthcare services and costs caused by nonchemotherapy drugs are considerable. Proactive strategies to manage and prevent drug-induced cytopenias should be considered.