COMBAT-MS is a research project investigating rituximab treatment for MS. We will compare rituximab to all other immunotherapies currently used for MS in a long-term observational study. This study is a collaboration between Kaiser Permanente Southern California (KPSC) and the Karolinska Institutet (KI). It is funded by PCORI for the duration of five years from 2016-2021. We will use collect data on efficacy, safety and patient reported outcomes through the Swedish MS Registry, other national registries in Sweden and KPSC data bases. This study is supported by stakeholders from NMSS, AAN, Neuro Sweden and The Swedish Neurological Society. It is independent of support from the pharmaceutical industry.