Health trajectories of patients with amyotrophic lateral sclerosis before and after initiation of non-invasive ventilation: a French nationwide database analysis

BACKGROUND: Management of amyotrophic lateral sclerosis (ALS) is complicated by heterogeneous presentation and unpredictable disease course. This study described disease trajectories before and after initiation of non-invasive ventilation (NIV) therapy in individuals with ALS, examined the relationship between NIV initiation timing and survival and analysed health trajectory clusters. METHODS: Data were extracted from the French national health insurance reimbursement system database for individuals with ≥1 reimbursement for NIV from January 2015 to December 2019, and ≥1 ALS disease code. Health trajectory clusters were determined using time sequence analysis through K-clustering. RESULTS: We analysed data from 3443 individuals with ALS (58% male, median age 67 years). The median (IQR) time from ALS diagnosis to NIV initiation was 10.8 (4.5-22.2) months and death occurred 21.5 (12.8-33.9) months after diagnosis. Tracheostomy/gastrostomy was performed in 3.9%/33.4% of patients, respectively. Unsupervised machine learning clustering identified four distinct patient groups. NIV initiation was late in two Clusters (A and B); these individuals were younger, had fewer comorbidities and more physiotherapy sessions before/after NIV. Survival after NIV initiation was longer in Clusters B and C; these individuals had lower rates of depression/anxiety, more prescription of mechanical in/exsufflation therapy and fewer home and emergency hospitalisations. Cluster B was unique, showing late NIV initiation and long post-NIV survival. This cluster was more likely to have spinal onset, a higher rate of obstructive sleep apnoea and fewer comorbidities. CONCLUSIONS: There was marked heterogeneity between patients with ALS and their care trajectories. Our data do not support a universal benefit for early initiation of NIV therapy.