Survival and treatment trends in ALS patients on home mechanical ventilation over 27 years in Sweden

<bold>Background and aims:</bold> In ALS, home mechanical ventilation (HMV) with invasive ventilation (IV) prolongs survival more than non-invasive ventilation (NIV). The incidence varies internationally. We aimed to explore regional discrepancies, temporal changes and survival related to HMV treatment types. <bold>Method:</bold> In the population-based DISCOVERY cohort study spanning 1996-2022, we analysed ALS patients with HMV, using data from the National Registry of Ventilatory Failure, Swedevox and the National Patient Registry. Predictors of IV were analysed using logistic regression adjusting for age, sex, start year, educational level, and origin from regions with a metropolitan area. <bold>Results:</bold> In 1,368 ALS patients, age and survival from diagnosis differed between treatment types (p<0.001): initial NIV (n=1,259 (92.4%); age 65.4±10.6 years, survival 1.8 years (95% CI 1.7-1.8)), initial IV (n=56 (4.1%), age 60.7±11.5 years, survival 4.7 years (2.8-6.1)), and transition from NIV to IV (n=47 (3.5%), age 54.5±11.4 years, survival 7.8 years (5.8-11.3)). Predictors of transition were more recent start year (OR 1.7/5 years (95% CI: 1.2-2.4), lower age (OR 0.4/10 years (0.3-0.6)), and origin from metropolitan areas (OR 3.9 (1.8-7.1)). More recent start year did not predict initial IV (OR 1.1 (0.8-1.5), but age (OR 0.7 (0.6-1.0)/10 years) and living in a metropolitan area (OR 2.1 (1.1-3.9) did. In 6/21 regions, transitions were sporadic (≤2 cases/27 years); in 12/21 regions, no transitions were noted. <bold>Conclusions:</bold> In ALS patients, HMV via IV were associated with longer survival than NIV. Transitions from NIV to IV were infrequent but increased over time and were practised with large geographical variations.