Re: Healthcare resource utilization by patients with treatment-refractory myasthenia gravis in England. Linda Harris, Sophie Graham, Sharon MacLachlan, Alex Exuzides & Saiju Jacob, J Med Econ 2019;22(7):691-697

Dear Editor, We would like to highlight two fundamental problems in aspects of the design and statistical analysis utilised by Harris et al. in their paper which was published in the JME 2019;22(7):691-697. We think the problems which we have identified with the matching of the myasthenia-gravis (MG) patients to non-MG patients and the statistical analysis applied to the resulting retrospective matched cohort data were capable of affecting the validity of some of the reported study findings.