A 60-year follow-up of the incidence and prevalence of XXXX in Hordaland County, Western Norway.

@entity1 @entity15 @entity560
OBJECTIVE: Investigate the incidence of @entity15 during 1953-2013 and estimate the prevalence rate of @entity15 on 1 January 2003 and 2013 in Hordaland County, Western Norway. METHODS: All @entity1 with onset of disease in Hordaland 1953-2013 were identified in files from previous studies until 2003 and from @entity1 records at the departments of Neurology, Haukeland University Hospital and Haugesund Hospital during 2003-2013. 1558 @entity1 were assessed and 1402 of these were included, of whom 1035 were alive and living in Hordaland at prevalence day 1 January 2013. Annual incidence rates were calculated for 1953-2013. RESULTS: On 1 January 2003, the crude prevalence rate was 191/100   000 population and on 1 January 2013, the crude prevalence rate was 211.4 (95% CI 198.3 to 224.2) per 100   000; 270.9 (95% CI 250.6 to 292.3) for @entity1 and 151.8 (95% CI 136.8 to 167.9) for @entity1 . Prevalence peaked at ages 55-59   years for @entity1 and 60-64   years for @entity1 . The annual incidence rate increased from 1.9 (95% CI 1.2 to 2.6) per 100   000 during 1953-1957 to 7.2 (95% CI 6.0 to 8.5) during 1978-1982 and to 8.5 (95% CI 7.3 to 9.7) during 2003-2007, thus indicating a stabilising incidence over the past 35   years. The female/male ratio ranged from 1.2:1 to 1.8:1 (p=0.381) during the period. CONCLUSIONS: Stabilising rather than increasing incidence combined with the stable female/male ratio are indicative of non-fluctuating environmental factors in a geographical area otherwise characterised by lack of @entity560 effective sun exposure. The rising prevalence of @entity15 could result from improved survival and follow-up methodology.
