Riluzole and prognostic factors in amyotrophic lateral sclerosis long-term and short-term survival: a population-based study of 1149 cases in Taiwan

Abstract

Background: Amyotrophic lateral sclerosis (ALS) is a rare disease in Taiwan; thus, estimation of ALS mortality is difficult. We evaluated factors associated with ALS survival in Taiwan.

Methods: The study enrolled 1149 Taiwanese with a primary diagnosis of ALS during 1999-2008. Follow-up information was available for all patients; mean (SD) duration of follow-up was 2.91 (2.62) years. Medical interventions, including noninvasive positive pressure ventilation (NIPPV), tracheotomy, gastrostomy, and riluzole, were included in time-dependent survival analysis.

Results: Of the 1149 ALS patients, 438 (38.12%) died during follow-up. Mortality in the first year was 16%, which was 13 times (95% CI 11.1-15.2) the age- and sex-standardized rate of the general population in Taiwan. The average annual crude mortality rate was 13.1% (person-years). Factors significantly associated with increased mortality were male sex, advanced age, rural residence, lower economic status, no tracheotomy, and no riluzole treatment. Significant predictors of long-term versus average survival were younger age at diagnosis, being a dependent or receiving social welfare, and NIPPV support. Significant predictors of short-term versus average survival were older age, being employed, no tracheotomy, and no riluzole use.

Conclusions: The results support the use of riluzole to improve ALS survival. Patients who received riluzole and underwent tracheotomy had the best survival.

Figure 1.. Kaplan-Meier survival curves from diagnosis for patients with amyotrophic lateral sclerosis in Taiwan, 1999–2008 (n = 1149). Solid line: predicted cumulative survival. Dashed line: 95% CI.

Figure 2.. Kaplan-Meier survival curves from diagnosis for patients with amyotrophic lateral sclerosis treated with riluzole and tracheotomy plus mechanical ventilation in Taiwan, 1999–2008 (n = 1149).