Epidemiology and factors predicting survival of amyotrophic lateral sclerosis in a large Chinese cohort

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder associated with loss of motor neurons. Our objective was to explore the epidemiology, clinical features, and survival factors of 1809 patients with ALS. Methods: We analyzed 1809 ALS patients, who were recruited from the Peking University Third Hospital from January 2005 to December 2015. Demographic data and disease-related parameters were collected. Kaplan-Meier curves were used to compare survival time. Cox proportional hazards function and the hazard ratio were used to identify adjusted prognostic predictors. Results: The results showed that the average annual incidence in Beijing alone was 0.38 cases/100,000 person-years and the mean age of onset was 48.88 +/- 11.35 (95% confidence interval [CI]: 48.17-49.85) years. The median survival time from onset to death/tracheostomy was 58.89 +/- 33.03 (95% CI: 51.46-63.84) months. In the adjusted Cox proportional hazard model, age of onset, diagnosis delay, rate of disease progression (Amyotrophic Lateral Sclerosis Functional Rating Scale Revised decline [points/month]), and body mass index all had an independent effect on survival in ALS. Conclusions: Our study provides information on epidemiology, clinical features, and survival factors of patients with ALS in China. These results can be helpful in clinical practice, clinical trial design, and validation of new tools to predict disease progression.