Clinical burden and healthcare resource utilization associated with myasthenia gravis: Assessments from a Japanese claims database

Objectives To compare the burden of illness for refractory and non‐refractory myasthenia gravis ( MG ) in Japanese patients. Methods Adults in a large Japanese health insurance claims database (1 September 2008 to 31 October 2016) were included in this retrospective, observational study if they had: at least two separate claims coded as MG by a neurologist; and continuous enrollment for 12 months after any MG claim (non‐refractory cohort) or the earliest claim associated with refractory disease (refractory cohort). A cohort with Parkinson's disease was used as the reference for the burden of illness of MG , and comprised patients matched (sex, age and index date) to patients with MG . Outcomes included respiratory failure, myasthenic exacerbations, outpatient hospital and emergency room visits, and hospitalizations. Results A significantly greater proportion of the refractory cohort ( n  =   165) than the non‐refractory cohort ( n  =   3137) experienced respiratory failure (17.0% vs 5.5%, respectively; P  < 0.001) and/or exacerbations (57.6% vs 5.8%, respectively; P  <   0.001) over 12 months. The mean numbers of hospitalizations (0.68 vs 0.09/year), emergency room visits (0.07 vs 0.03/year) and outpatient hospital visits (16.79 vs 11.88/year), and the mean duration of hospital stays (22.19 vs 2.81 days/year) were also significantly greater for the refractory cohort (all P  <   0.001). Except for emergency room visits, healthcare resource utilization was significantly greater for non‐refractory MG than for Parkinson's disease ( n  =   3168). Conclusions In Japanese patients, refractory MG is associated with a greater clinical burden and healthcare resource utilization than non‐refractory MG .