Amyotrophic lateral sclerosis mortality in Latin America: A population based meta-analysis.
Résumé
Introduction: Recent studies described a lower occurrence of ALS in Latin America compared to Europe and North America (1). Furthermore, significant differences in ALS risk have been described between ethnic groups in the region (2,3). We conducted a meta-analysis using general population data aiming to describe ALS mortality rates in Latin America. We explored the relationship between mortality rates and the proportion of Caucasian population. Methods: National mortality registers from Latin American countries were searched to identify ALS deaths according to the International Classification of Diseases (ICD 9th: code 335.2 and ICD 10th: code G12.2). The crude and standardized mortality rates were calculated. A random-effect meta-analysis was conducted to estimate pooled mortality. Linear regression assessed the relationship between mortality rate and proportion of Caucasian population. Results: Overall, 28 548 ALS deaths and 819 million person-years of follow-up (PYFU) were considered from 10 Latin American countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Guatemala, Mexico and Uruguay. Standardized mortality varied among countries. The highest mortality rates were observed in Uruguay and Costa Rica at 1.3 and 1.2 per 100 000 PYFU, respectively. Pooled crude mortality rate was 0.38 (95%CI: 0.27 – 0.52) and pooled standardized mortality was 0.61 (95%CI: 0.49 – 0.77) per 100 000 PYFU. Heterogeneity was highly significant (I2: 99.9%, p=0.000). A strong positive correlation was reported between ALS mortality rates and the proportion of Caucasians (R: 0.83; p=0.003). Conclusion: This meta-analysis confirms a lower ALS occurrence in Latin America compared to Europe and North America. It also supports an epidemiological association between ethnic populations and ALS. Further studies are needed to investigate the role of ancestral origin on ALS