title: Prevalence and incidence of multiple sclerosis in Oppland County: a cross-sectional population-based study in a landlocked county of Eastern Norway.
abstract: OBJECTIVES - We report the prevalence and incidence rates of multiple sclerosis (MS) in Oppland County, Norway. METHODS - Records from all patients diagnosed with MS at the two Oppland County hospitals, Gjøvik and Lillehammer during 1989-2001 were evaluated. In addition, all general practitioners in Oppland County reported their patients into the study. RESULTS - The age-adjusted prevalence rate of definite MS was 174.4/ 100 000 on the prevalence day 1 January 2002. When the probable cases were included, the prevalence rate rose to 185.6/100 000. The highest prevalence rates were detected in the northern mountain areas, thus corroborating the results from previous local surveys 30-50 years ago. The prevalence of MS was statistically significantly associated with climatic, socioeconomic and geographic variables in the county. The age-adjusted incidence of definite and probable MS in Oppland County was 6.6/100 000 during 1989-1993 increasing to 7.6/100 000 during 1994-1998. DISCUSSION - We found the highest prevalence rates of MS ever reported in Norway. Our findings indicate a possible influence of environmental factors.
authors.affiliation: Department of Rehabilitation, Sykehuset Innlandet HF, Gjøvik, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Risberg
authors.forename: Jan Harald
authors.initials: JH
authors.lastname: Aarseth
authors.forename: Harald
authors.initials: H
authors.lastname: Nyland
authors.forename: Klaus
authors.initials: K
authors.lastname: Lauer
authors.forename: Kjell-Morten
authors.initials: KM
authors.lastname: Myhr
authors.forename: Rune
authors.initials: R
authors.lastname: Midgard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002980:Climate; D003430:Cross-Sectional Studies; D005260:Female; D005843:Geography; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D012959:Socioeconomic Factors; D055815:Young Adult