Long-Term Use of Riluzole Could Improve the Prognosis of Sporadic Amyotrophic Lateral Sclerosis Patients: A Real-World Cohort Study in China

Abstract

Objectives: To investigate the effectiveness of riluzole in a long-term follow-up of cohort with sporadic amyotrophic lateral sclerosis (ALS) in a real-world study. Methods: Patients with ALS between 2007 and 2013 were followed up every 3 months. Survival and tracheotomy were predefined as primary outcome measures. The cumulative defined daily dose (cDDD) of riluzole was estimated. The patients in the riluzole group were classified into 1 of 3 subgroups according to the cDDD quartiles. Survival was analyzed using Kaplan-Meier and Cox regression analysis. Results: Of the 1,540 ALS patients, 415 (26.9%) used riluzole, and the remainder did not. In the riluzole group, the age at onset was greater (p = 0.016), the diagnostic delay was shorter (p < 0.0005), the body mass index (BMI) was higher (p < 0.0005), and the scores for both the functional rating scale (FRS) and the revised FRS (FRS-R) were higher (both p < 0.0005) than those of the control group. The median cDDD of riluzole was 28 (2,800 mg). Although Kaplan-Meier analysis did not reveal a significant difference between the two groups (p = 0.780), it showed that the prognosis of the beyond quartile 3 subgroup [cDDD ≥ 168 (16,800 mg)] was significantly better than that of the other groups [adjusted HR 0.488 (0.320-0.746), p = 0.001]. Conclusion: In China, older ALS patients and patients who had a higher BMI, shorter diagnostic delay, and higher FRS or FRS-R scores were more likely to use riluzole. Long-term use of riluzole was associated with a better prognosis for ALS patients, whereas short-term use had little effect on survival.

Keywords: Chinese cohort; amyotrophic lateral sclerosis; prognosis; real-world study; riluzole.

FIGURE 1

Kaplan-Meier survival curves. (A) Survival analysis stratified by riluzole; (B) Survival analysis stratified by quartiles of dose of riluzole.

FIGURE 2

Survival curves after adjusting for age, gender, BMI, diagnostic delay time, phenotype, Airlie House category at presentation, residence, FRS score, history of smoking or alcohol abuse, contact history of harmful gas or pesticides at the covariate means using Cox regression model. (A) Survival analysis stratified by riluzole; (B) Survival analysis stratified by quartiles of dose of riluzole.