Evolution of Home Mechanical Ventilation in Sweden Over 27 Years: Changing Trends in Incidence, Prevalence, and Patient Characteristics - The Population-Based DISCOVERY Study

Abstract

BackgroundHome mechanical ventilation (HMV), non-invasive ventilation (NIV) or invasive ventilation (IV) outside a hospital setting is a key treatment to improve outcomes in chronic hypoventilation. Research questionWhat are the temporal trends observed over 27 years in Sweden regarding the incidence, prevalence, diagnostic spectrum, and patient characteristics associated with HMV? Study design and methodsNational, population-based, longitudinal analysis of the DISCOVERY study of patients initiating HMV between 1996 and 2022. Time trends stratified by the underlying diagnosis group (lung disease, predominantly chronic obstructive pulmonary disease (COPD), restrictive thoracal diseases (RTD), obesity hypoventilation syndrome (OHS), neuromuscular diseases (NMD), amyotrophic lateral sclerosis (ALS), and other neurological disorders) were analysed using linear regression models. ResultsWe included 10,555 patients ≥16 years (aged 63±15 years, 50 % women). Between 1996-98 and 2020-22, the HMV incidence increased threefold to 7/100,000, and the prevalence sixfold to 33/100,000. The most common indication for incident HMV shifted from RTD (35% in 1996-98 to 3% in 2020-22) to lung disease (14 to 31%), OHS (23 TO 33%), and ALS (4 TO 14%) by 2020-22 (p<0.001). The proportion of women increased from 47% to 54% (p<0.013, and the age at initiation of HMV increased from 58±15 to 66±14 years (p<0.001). Lung function measured as vital capacity at treatment start increased significantly in all diagnosis groups except for OHS, where both VC and forced expiratory volume in 1 second (FEV1) decreased. In the registry's first and last three-year periods, the proportion of patients ventilated invasively decreased from 10% to 2% (p<0.001). ConclusionIn 27 years to 2022, the incidence and prevalence of HMV in Sweden have increased markedly, patient demography has changed, and IV has decreased. The average age of patients initiated on HMV has increased, but treatment is started earlier in the disease trajectory.