(58) Use of Riluzole and Risk of Hospitalization for Patients with Motor Neuron Disease in Hong Kong: A Self-Controlled Case Series Study

Publication Number: 732

Background: Motor neuron diseases (MND) are a group of neurodegenerative disorders that affect the motor neurons in the brain and spine. Riluzole is a supportive therapy for amyotrophic lateral sclerosis (ALS), a subtype of MND. The mechanism of action for riluzole is debatable. Limited studies explored its effect on risk of hospitalization.

Objectives: This study aims to explore the use of riluzole and risk of all-cause hospitalization among people diagnosed with MND.

Methods: This self-controlled case series (SCCS) study includes incident MND patients with riluzole from 1993 to 2018 in Hong Kong. The data was collected from a clinical electronic database, the Clinical Data Analysis and Report System, covering all Hong Kong public hospitals. The endpoint of interest is the hospital admission for any reason within two years after the initiation of riluzole. The SCCS study design was conducted to investigate the direct effect of Riluzole on hospital admission. The included patients were followed from one year before their first MND diagnosis date (diagnosis or first riluzole prescription or the earliest available date of Riluzole, whichever come later) until the study end date (1st Jan 2019), death date, or prescription start date of first edavarone use (if any). We will censor the observation period when the patient is exposed to edavarone because its use may affect the association between riluzole and hospitalization. The risk period in SCCS was divided into six windows: no riluzole prescription (baseline period), 30 days before the riluzole (pre-exposure period), and the prescription period of riluzole (0 to 61 days, 61 to 120 days, 121 to 180 days after riluzole, and 181 days after till the end of the prescription). Age is adjusted by using a one-year age band. Incidence rate ratio and its 95% confidence interval was estimated by conditional logistic regression.

Results: In the study period, 204 patients were included for SCCS analysis. Elevated IRRs were detected in all risk periods. The risk periods with statistically significant include the pre-exposure period [IRR, 95% confidence interval: 2.66 (2.10-3.37)] periods from 0 to 60 days (1.44, 1.08-1.92) and 61 to 120 days (1.47, 1.05-2.07).

Conclusions: Elevated IRRs of hospitalization were detected for MND patients prescribed with Riluzole in the first four months. Intensive monitoring could be attributed to the increased risk of hospitalization shortly after initiation of riluzole. More studies rather than survivorship are needed for riluzole in MND patients.