Objectives and methods: National guidelines for immunomodulatory treatment in multiple sclerosis (MS) were established in Norway in 2001. However, the nation-wide treatment practice has not been evaluated since. We therefore obtained information of all patients who have received prescriptions for the approved immunomodulatory medications, interferon-beta (Betaferon, Avonex, Rebif) and glatiramer acetate (Copaxone) registered in the Norwegian Prescription Database (Reseptregisteret). We also made a survey of patients treated with mitoxantrone (Novantrone) as well as patients supplied with immunomodulatory drugs in treatment trials. To further calculate the treatment frequency, a nation-wide prevalence of MS in Norway was estimated, based on available prevalence studies.
Results: The estimated frequency of MS was approximately 150/100,000 in southern Norway and 100/100,000 in northern Norway. The treatment frequencies varied from 15% to 47% between the different counties with a frequency of 28% for the whole country.
Conclusion: Substantial differences in treatment frequencies between counties were detected, reflecting major differences in clinical practice within the country. This calls for increased focus on clinical application of the established treatment guidelines.