OBJECTIVES: To estimate all-cause direct and indirect costs among employed patients with newly diagnosed (ND) vs pre-existing (PE) myasthenia gravis (MG) in Sweden.

METHODS: Data were linked from four Swedish nationwide population-based registries. Adults with ≥ 2 primary diagnosis of MG (ICD-10-SE:G70.0) in inpatient or outpatient specialist visits (≥ 12 months apart within 24 months, ≥ 1 MG diagnosis recorded by neurologist) during 1/1/2010-12/31/2017 were selected. Index date was date of first primary MG diagnosis. Patients were required to have standing employment and a record of pharmacological treatments for MG. Patients were categorized into ND vs PE groups based on whether they had MG diagnosis prior to index date (back until 2001). All-cause direct costs due to inpatient, outpatient specialist visit and prescription use, as well as indirect costs associated with sickness absence, were compared between two groups during 12-month post-index period.

RESULTS: A total of 370 employed MG patients were included, of which 158 patients were ND MG [mean (±SD) age 48.1 (±12.3) years; 57% were female]. The mean all-cause costs of MG patients were €14,200, with direct costs of €8,714 and indirect costs of €5,486. Compared to PE group, ND MG had higher all-cause hospitalization rates (64.6% vs 34.9%, p<0.01); experienced nearly 6.5 more hospitalization days (p<0.01); incurred €6435 higher direct costs (p<0.01), with an incremental difference of €4916 due to inpatient costs. ND group reported higher percentage of ≥ 1 sick leave (53.2% vs 32.5%, p<0.01), with 31 more days of sickness absence (p<0.01) and €3513 higher indirect costs (p<0.01) than PE group.

CONCLUSIONS: Indirect costs accounted for nearly 40% of total all-cause costs among employed MG patients, with significantly higher costs in the first year compared to later years. Early diagnosis and effective treatment may be important factors to reduce the burden in ND MG patients.