Riluzole and other prognostic factors in ALS: a population-based registry study in Italy

OBJECTIVE: In this prospective population-based registry study on ALS survival, we investigated the role of riluzole treatment, together with other clinical factors, on the prognosis in incident ALS cases in Emilia Romagna Region (ERR), Italy. METHODS: A registry for ALS has been collecting all incident cases in ERR since 2009. Detailed clinical data from all patients diagnosed with ALS between 1.1.2009 and 31.12.2014 have been analyzed for this study, with last follow up date set at 31.12.2015. RESULTS: During the 6 years of the study, there were 681 incident cases with a median tracheostomy-free survival of 40 months (95% CI 36-44) from onset and of 26 months (95% CI 24-30) from diagnosis; 573 patients (84.14%) were treated with riluzole, 207 (30.39%) patients underwent gastrostomy, 246 (36.12%) non invasive ventilation, and 103 (15.15%) invasive ventilation. Patients who took treatment for ≥ 75% of disease duration from diagnosis had a median survival of 29 months compared to 18 months in patients with < 75% treatment duration. In multivariable analysis, factors independently influencing survival were age at onset (HR 1.04, 95% CI 1.02-1.05, p < 0.001), dementia (HR 1.56, 95% CI 1.05-2.32, p = 0.027), degree of diagnostic certainty (HR 0.88, 95% CI 0.78-0.98, p = 0.021), gastrostomy (HR 1.46, 95% CI 1.14-1.88, p = 0.003), NIV (HR 1.43, 95% CI 1.12-1.82, p = 0.004), and weight loss at diagnosis (HR 1.05, 95% CI 1.03-1.07, p < 0.001), diagnostic delay (HR 0.98, 95% CI 0.97-0.99, p = 0.004), and % treatment duration (HR 0.98, 95% CI 0.98-0.99, p < 0.001). CONCLUSIONS: Independently from other prognostic factors, patients who received riluzole for a longer period of time survived longer, but further population based studies are needed to verify if long-tem use of riluzole prolongs survival.