Health Trajectories around Noninvasive Ventilation Initiation for Obesity Hypoventilation Syndrome

Rationale: Positive airway pressure therapy modalities in obesity hypoventilation syndrome (OHS) are still debated. Objectives: To describe health trajectories before and after starting noninvasive ventilation (NIV) and compare post-NIV outcomes between groups with different pre-NIV trajectories. Methods: Data came from the French national health insurance reimbursement database for individuals with OHS and one or more NIV prescriptions between January 1, 2015, and December 31, 2019. Health trajectory clusters were determined using mixture models that were graphically represented by time sequence analysis. Results: Data from 8,842 individuals were analyzed (59.7% had coexisting obstructive sleep apnea, 64% had one or more comorbidities). Median follow-up was 3.1 years. Cluster 1 (n = 5,853; 66.2%) started NIV while stable after pulmonary function testing, arterial blood gas (ABG) analysis, and sleep studies; 23.7% underwent bariatric surgery around NIV initiation. One-year therapy termination and mortality rates were 51.8% and 5.5%, respectively. Cluster 2 (n = 757; 8.6%) started NIV during or immediately after one or more acute intensive care unit hospitalizations in the previous year; 1-year NIV termination and mortality rates were 34.3% and 9.1%, respectively. Cluster 3 (n = 526; 5.9%) had NIV initiation after a sleep study, pulmonary function testing/arterial blood gas analysis, and approximately 3 months of continuous positive airway pressure; 1-year therapy termination and mortality rates were 23.0% and 2.1%, respectively. In cluster 4 (n = 1,706; 19.3%), long-term continuous positive airway pressure preceded the switch to NIV after reassessment in ambulatory care; 1-year therapy termination and mortality rates were 18.4% and 4.5%, respectively. Conclusions: These novel data highlight marked heterogeneity in OHS and use of positive airway pressure therapies, which significantly impacts outcomes.