Non-self-sufficiency as a primary outcome measure in ALS trials

Our objective was to assess non-self-sufficiency (NSS) in ALS as an outcome measure in therapeutic trials. Using data from the control arm of two randomized trials and an observational study, associations between NSS (score ≤2 in the ALSFRS-R items for swallowing, cutting food and handling utensils, or walking) and the total ALSFRS-R score, forced vital capacity (FVC), and survival at selected time-points until death or 48 weeks, were assessed. These measures were used as surrogates of relevant functional impairment. Of 82 self-sufficient (SS) patients at baseline, 32 (39.0%) became NSS at four weeks and increased to 72 (87.8%) at the end of follow-up. A significant association was found between NSS, ALSFRS-R score and FVC at 24, 36 and 48 weeks. Thirty-four subjects died (41.5%). Compared to SS patients (median survival, 27.9 months), individuals becoming NSS at four weeks were at increased risk to die (median survival, 23.6 months, p = 0.02). NSS status at four weeks predicted survival even after adjustment for ALSFRS-R total score, age, gender, site of onset, disease duration, BMI, and FVC. Walking was the only predictor of survival when adjusting for all covariates. In conclusion, NSS status is a possible endpoint to investigate short-term efficacy of treatments of ALS.