Diagnostic testing and treatment in Japanese patients with a diagnosis code for chronic inflammatory demyelinating polyradiculoneuropathy: A claims database analysis

Objectives

Reports of real-world data concerning chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are limited in Japan. This study aimed to investigate the diagnostic testing and treatment performed in patients diagnosed with CIDP in Japan.

Methods

Using a Japanese commercial medical information database, we analyzed diagnostic tests, differential diseases, and treatments for patients with a diagnosis code for CIDP between April 13, 2008 and August 31, 2018.

Results

Of the 4564 patients with a diagnosis code for CIDP, 1658 patients were confirmed as newly assigned with the diagnosis code during the study period. Diagnostic tests performed before assignment of the diagnosis code for CIDP included nerve conduction studies in 48.1%, magnetic resonance imaging in 40.5%, and cerebrospinal fluid tests in 38.4%. Other diseases with codes that were assigned at the time of the CIDP diagnosis included Guillain–Barré syndrome in 8.1%, Sjögren syndrome in 4.4%, and systemic lupus erythematosus in 3.7%. Initial treatments performed after the assignment of the new diagnosis code for CIDP were intravenous immunoglobulin (IVIg) in 54.3%, corticosteroids (CS) in 45.4%, and plasmapheresis in 2.3%. The event-free survival rates for predefined specific safety-related events at 1000 d were 90.0% for any event in patients receiving IVIg monotherapy and 71.7% for any event in patients receiving CS monotherapy.

Conclusion

Diagnostic testing and treatment performed in clinical practice was shown through the analysis of real-world data of Japanese patients with a diagnosis code for CIDP. These findings might contribute to developments in clinical practice for Japanese CIDP patients.