Home mechanical ventilation for amyotrophic lateral sclerosis–a national study of survival and treatment trends across 27 years

RATIONALE: Home mechanical ventilation (HMV) improves survival in Amyotrophic lateral sclerosis (ALS) and may be provided non-invasively (NIV) or invasively (IV). While NIV is guideline-recommended, the role of IV remains controversial, and data on long-term outcomes and NIV-to-IV transitions are limited. OBJECTIVES: To examine survival across HMV strategies in people with ALS (pwALS) in Sweden over 27 years, factors associated with IV initiation, temporal trends in IV use and survival, and regional variation in IV utilisation. METHODS: A longitudinal cohort study of pwALS in the Swedish National Registry of Ventilatory Failure (Swedevox) 1996-2022, cross-linked with national registries. Factors associated with mortality and treatment patterns were assessed using multivariable regression models. RESULTS: Among 1,360 pwALS, initial NIV was most common (92%), followed by IV (5%) and NIV-to-IV transitions (3%). Most IV initiations were non-elective (77% vs. 18% NIV, p < 0.001). NIV-to-IV transitions occurred mainly in metropolitan areas (OR 5.11; 95% CI 2.30-11.4). Median survival differed across observed treatment pathways (p < 0.001): 1.7 years with NIV, 4.9 years with IV, and 6.5 years with NIV-to-IV. Mortality was associated with higher age (aHR 1.33 per decade; 95% CI 1.26-1.41), female sex (aHR 1.15; 95% CI 1.02-1.29), and acute initiation (aHR 1.26; 95% CI 1.08-1.47). Longer time from diagnosis to NIV initiation was associated with reduced mortality risk (aHR 0.58 per year; 95% CI 0.55-0.62). Over time, patients initiated HMV at older age with better lung function and lower PaCO2 values among those with available measurements, whereas overall survival remained unchanged. CONCLUSION: Patients receiving IV had longer observed survival, likely reflecting the benefits of a secured airway as well as patient selection and underlying disease trajectory. Most IV initiations were unplanned. Over three decades, HMV was initiated in older patients at an earlier stage of respiratory decline, but overall survival remained unchanged. IV use increased with marked regional variation.