Real‐world burden and treatment of chronic rhinosinusitis in Japan: A retrospective claims database analysis

Objectives: Chronic rhinosinusitis (CRS) is a heterogeneous disease, which can be subdivided into CRS with (CRSwNP) or without (CRSsNP) nasal polyps. An intractable form of CRSwNP that is associated with an eosinophil-dominant inflammatory cell infiltration (eosinophilic CRS) has become more prevalent in Japan. There is currently limited information on the burden of CRS in Japan and treatment approaches used in real-world practice. Methods: This retrospective, observational, comparative cohort study used information from the Japanese JMDC insurance claims database (study period April 1, 2015, to March 31, 2020). A CRS cohort was identified and matched with a control group without CRS. The primary objective was to clarify disease burden and treatment approaches by comparing comorbidities, healthcare resource utilization (HRU), and drug prescriptions in the CRS and non-CRS groups. Results: In total, 23,256 individuals with CRS (1762 with CRSwNP and 21,494 with CRSsNP) were matched with 23,256 controls. The mean age was 45 years and the majority of individuals were male (57%). Individuals with CRS had a higher disease burden than controls, with more frequent comorbidities (particularly, type 2 inflammatory disease [e.g., allergic rhinitis and asthma], and those caused by systemic corticosteroids [SCS]), and higher HRU (including outpatient visits, laboratory examinations and surgical procedures). Further, individuals with CRS were prescribed more medications, both for CRS (including SCS) and non-CRS conditions, than controls. Conclusion: In Japan, CRS is associated with a high disease burden, and multiple treatment approaches are used in affected individuals, including long-term SCS, which is generally not recommended. Level of Evidence: 3.