Ethnic and demographic incidence of amyotrophic lateral sclerosis (ALS) in Brazil: A population based study

Our objectives were to examine demographic and ethnic factors associated with amyotrophic lateral sclerosis in Brazil. The method used was a retrospective study of death certificates performed in June 2015, identifying the incidence of amyotrophic lateral sclerosis over 10 years, from January 2004 to December 2013, related to gender, age and race. Results revealed 8942 death certificates with 8152 as the underlying cause and 790 as a secondary cause. The average age was 62.7 ± 13.2 years, with a predominance of males (1·3:1). The adjusted mortality rate over 20 years was 0.61 to 0.89/100,000 person-years, and over 45 years was 1.77 to 2.3/100,000 person-years. There was a predominance of amyotrophic lateral sclerosis in Caucasians compared to the general population above 20 years (2010 Census), with an odds ratio (OR) of 2.92 (95% CI 2.78-3.07). The OR in blacks was 0.04 (95% CI: 0.03-0.04), in mestizos was 0.05 (0.04-0.07), and in Indians was 0.02 (0.01-0.04). The mean age was lower than in European populations (48.5 ± 12.3 years) (p < 0.0001). In conclusion, the incidence of amyotrophic lateral sclerosis in Brazil is close to other Latin American populations, with a lower age at death and clear predominance in Caucasians.