Fig. 2.

Primary and secondary case-definition algorithms which together form the ‘gold standard’ to identify the confirmed MS diagnoses registered in the Swedish National Patient Register (NPR) by validating against individual-level information from other register data sources. Notes Given that patients with clinically isolated syndrome (CIS) should be kept as uncertain MS, and may be treated with a subset of DMTs, the following DMTs and ATC codes were not included in the algorithm: Interferon beta 1-a: L03AB07, Interferon beta 1-b: L03AB08, and Glatiramercetat: L03AX13. ATC Anatomical Therapeutic Classification, CDR Cause of Death Register, CIS clinically isolated syndrome, DMT disease modifying therapies, ICD International Classification of Disease, LISA Longitudinal Integration Database for Health Insurance and Labour Market Studies, MiDAS Micro-Data for Analysis of the Social Insurance System, MS multiple sclerosis, NPR National Patient Register, SPDR Swedish Prescribed Drug Register, SMSReg Swedish MS Register