The economic burden of pleural effusions in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors.

Objective: Tyrosine kinase inhibitors (TKI), the standard of care for patients with chronic myeloid leukemia (CML) patients, may in some cases lead to the development of pleural effusion (PE). The purpose of this study is to compare healthcare resource utilization and costs associated with PE among CML patients treated with a TKI therapy.

Methods: Two large retrospective claims databases (1999-2009) were combined to identify adult CML patients who received ≥1 TKI prescription before the index date, which was defined as 30 days before the first PE diagnosis for patients with PE and a randomly selected date for PE-free patients. Patients were followed for 6 months after the index date. PE and PE-free patients were matched on a 1:1 ratio. PE-related resource utilization and costs (measured in 2009 US dollars) were estimated for PE patients. All-cause and CML-related resource utilization and costs were compared between PE and PE-free patients. Multivariate regression models were used to control for confounding factors.

Results: The study included 186 matched pairs. PE-free and PE patients were on average 65.4 and 63.6 years old and 39.8% and 48.9% were female, respectively. PE patients had a significantly higher number of inpatient (IP) days, IP admissions, outpatient (OP) visits and emergency room (ER) visits than PE-free patients (all p < 0.01). All-cause medical services costs were $88,526 and $30,434 for PE and PE-free patients, respectively. After adjusting for confounding factors, the PE-related total medical costs were $47,288 (p < 0.01), which was mostly accounted for by higher IP (difference: $34,123, p < 0.01) and OP (difference: $9563, p < 0.05) costs. PE patients also incurred higher CML-related medical costs compared to PE-free patients (difference: $39,599; p < 0.01).

Conclusion: PE presents a substantial economic burden for CML patients treated with TKI.