Current treatment patterns and medical costs for multiple myeloma in Japan: a cross-sectional analysis of a health insurance claims database.

Aims: Various drugs have recently been launched for the treatment of multiple myeloma (MM). This increase in the number of treatment options has potentially changed treatment patterns and medical costs for patients with MM. Japanese public health insurance claims were analyzed to examine the change in the treatment patterns of MM drugs and medical costs per patient.Materials and methods: A claims database provided by Medical Data Vision was used, which includes data from ∼20 million patients from >300 acute care hospitals across Japan. The type of MM drugs prescribed and medical costs for patients with MM between April 2008 and December 2016 were examined using monthly cross-sectional analyses. Patients with an International Classification of Diseases, 10th Revision (ICD-10) diagnosis code of C90.0 were classified as having MM. MM drugs were defined by generic names.Results: In total, 19,137 patients with MM (average age at first diagnosis: 69.6 years; percentage of women: 47.9%) were identified from the database. The percentage of patients prescribed each MM drug changed substantially as novel drugs were launched. Total medical costs increased until 2010, then stabilized. MM drug costs increased from approximately 2010, but costs for other care decreased, particularly for hospitalization (including surgery).Limitations: The database contained data from large, acute care hospitals, which may have caused bias in terms of patients' clinical history and disease severity.Conclusions: Total medical costs for MM have remained stable since 2010. MM drug costs increased, but costs for other care decreased after the launch of lenalidomide in 2010 and other drugs in 2015 and later. More detailed research is required to confirm whether the launch of novel drugs caused the changes in medical costs.