BACKGROUND: Myasthenia gravis is a rare autoimmune neuromuscular disorder. The 
disorder requires long-term use of expensive medication to control clinical 
symptoms. This study analyzed the change in trends of total medical expenses and 
out-of-pocket expenses for patients with myasthenia gravis and explored the 
factors influencing them.
METHODS: In this retrospective study, data were derived from a survey of medical 
service utilization for patients insured by the Urban Basic Medical Insurance in 
China from 2013 to 2015. The cost data of 3347 patients with myasthenia gravis 
were included in this study. The baseline characteristics and medical expenses 
for patients with myasthenia gravis were analyzed using a descriptive method. 
The difference and influencing factors of the out-of-pocket ratio were analyzed 
from both outpatient and inpatient expenses by using the quantile regression 
method.
RESULTS: The total expenses reimbursed by the Urban Basic Medicine Insurance for 
all patients with myasthenia gravis fell progressively from 73.1 to 58.7% during 
the study period. Patients' out-of-pocket expenses increased gradually, of which 
expenses within the scope of Basic Medicine Insurance increased from 14.7 to 
22.6% and expenses outside of the Basic Medicine Insurance scope increased from 
12.6 to 18.7%. Moreover, the panel quantile results showed a positive 
correlation between the year of receiving treatment and the out-of-pocket ratio. 
In addition to the 25th quantile of the out-of-pocket ratio among outpatients 
with myasthenia gravis, there were significant differences in medical insurance 
and medical institution among all the other quantiles. Significant regional 
differences were found in all quantiles of the out-of-pocket ratio, except for 
the 75th quantile among inpatients. Lastly, age had a negative effect on 
inpatients with myasthenia gravis across all quantiles, but not on outpatients.
CONCLUSIONS: From 2013 to 2015, patients with myasthenia gravis's out-of-pocket 
expenses increased progressively. Moreover, the individual out-of-pocket ratio 
was affected by the year, medical insurance, medical institution, region, and 
age. The current medical insurance policy for the general public has a low 
ability to cater for patients with myasthenia gravis.