Characteristics and factors associated with mortality due to rare diseases in Chile, 2002-2017

Introduction: Rare diseases are characterized by their low prevalence, chronically debilitating and life-threatening nature. Objective: To determine the characteristics and factors associated with mortality due to rare diseases in Chile from 2002 to 2017. Materials and methods: We conducted an analytical cross-sectional study based on secondary mortality database from the Departamento de Estadística e Información en Salud (DEIS), Ministerio de Salud de Chile (Department of Statistics and Health Information, Chile Ministry of Health) from 2002 to 2017. The specific mortality rates adjusted by age and sex were calculated. A normality analysis was conducted using the Kolmogorov-Smirnov test. In addition, a chi-square test of independence for associations and multivariate logistic regression was applied to determine the probability of death. Results: Between 2008 and 2012 there were 10,718 deaths due to rare diseases, 53.2% of them occurred among women. The average annual mortality rate was 3.9 per 100,000 inhabitants: 4.1 in women and 3.8 in men. The main causes of mortality among women were Creutzfeldt-Jakob disease, anencephaly and autoinmune hepatitis, and among men, Creutzfeldt-Jakob disease, muscular dystrophy and anencephaly. Women are 1.75 times more likely to die than men (adjusted Odds Ratio (aOR) = 1.75; 95% CI: 1.69 - 1.82). The highest probability of dying occurred among children aged 0-4 years (aOR = 15.30; 95% CI: 14.10 - 19.20). Conclusion: Overall, the burden of mortality due to rare disease was higher among women of all ages in Chile between 2002 and 2017.