Completeness

The completeness of the Danish Multiple Sclerosis Registry (DMSR) has been estimated to be approximately 90%, higher for cohorts with older onset and lower for cohorts with onset close to follow-up. The validity of the diagnosis for autopsy cases classified as definite Multiple Sclerosis (MS) in the Registry was estimated to 94%. Data on patients receiving DMT is virtually complete due to mandatory registration of MS-patients treated with disease modifying treatments (DMT).

Current data

The DMSR is linked with other registers:

The Danish Civil Registration System provides all Danish citizens, alive in 1968 and thereafter, with a unique 10-digit person ID (CPR-nr), the first 6 digits being the date of birth. The CPR-nr enables linkage with other registries and provides the DMSR with complete vital status and dates of death or emigration.
The Danish National Patient Registry (NPR) contains time of admission and ICD-codes for all in- and out-patient hospital contacts in Denmark.

To provide an accurate, unbiased estimate of the number of MS-cases in the population, capture- recapture methods are used to ensure completeness of the DMSR. The DMSR receives a monthly list of all patients assigned to each MS clinic and control of correct case-definition has a high priority for the DMSR.

Neurologists use our online-platform COMPOS in the clinic as it provides an updated picture of the entire disease course illustrated with intuitive graphics. With COMPOS integrated in the workflow, we are ensuring high quality recording of patient visits which in turn ensures scientific validity of the registered data. The data collection software has an integrated data verification tool to identify missing or incoherent data.

Number of Registered Cases

The total number of registered cases with Clinically Isolated Syndrome (CIS) and MS by the start of 2020 were 30,023 of whom 16,515 were alive, resulting in a prevalence rate of about 284 per 100,000 population. The mean annual number of new cases receiving a MS diagnosis was 649 per year in the period 2010 to 2019.

In total, 7,945 patients (48.1 %) are receiving DMT at the start of May 2020. An annual report is drafted of all patients included in the DMSR.

Treatment history for patients has been registered from 1996. Side effects from treatment have been reported from the beginning and were optimized to contain more details since 2018. Relapses, EDSS and MRI have been regularly reported, increasingly after treatments became available.