The Danish Multiple Sclerosis Registry (DMSR) was formally established in 1956 and was based on a nationwide prevalence survey, but prospective data collection started already in 1948 and has continued until now.
The target population of the DMSR are all Danish citizens, who have received a diagnosis of MS by a neurologist or a Department of Neurology (including the two Danish MS Rehabilitation Hospitals). The diagnostic criteria were until 1994 those of Allison & Millar; from 1994 the Poser criteria; and from 2005 the McDonald criteria.