Mortality trends of amyotrophic lateral sclerosis in Norway 1951–2014: an age–period–cohort study

Recent studies suggest that the incidence and mortality of amyotrophic lateral sclerosis (ALS) are increasing. Changing environmental factors could influence disease risk differently throughout life span, and also between genders, birth cohorts, and seasons of birth. We aimed at describing long-term ALS mortality trends in Norway between 1951 and 2014 using age–period–cohort analysis. The Norwegian Cause of Death Registry provided ALS mortality data that were age- and sex-adjusted through direct standardization. Poisson regression analyses were used for identification of mortality trends and potential month of birth effects. We identified 5345 ALS cases, of which 54.7 % were men. ALS mortality increased throughout the whole period ( p