Morbidity and mortality reduction associated with polysomnography testing in idiopathic pulmonary fibrosis: a population-based cohort study

Abstract

Background: It is not well-known if diagnosing and treating sleep breathing disorders among individuals with idiopathic pulmonary fibrosis (IPF) improves health outcomes. We evaluated the association between receipt of laboratory-based polysomnography (which is the first step in the diagnosis and treatment of sleep breathing disorders in Ontario, Canada) and respiratory-related hospitalization and all-cause mortality among individuals with IPF. Methods: We used a retrospective, population-based, cohort study design, analyzing health administrative data from Ontario, Canada, from 2007 to 2019. Individuals with IPF were identified using an algorithm based on health administrative codes previously developed by IPF experts. Propensity score matching was used to account for potential differences in 41 relevant covariates between individuals that underwent polysomnography (exposed) and individuals that did not undergo polysomnography (controls), in order minimize potential confounding. Respiratory-related hospitalization and all-cause mortality were evaluated up to 12 months after the index date. Results: Out of 5044 individuals with IPF identified, 201 (4.0%) received polysomnography, and 189 (94.0%) were matched to an equal number of controls. Compared to controls, exposed individuals had significantly reduced rates of respiratory-related hospitalization (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.24–0.75), p = 0.003) and all-cause mortality (HR 0.49, 95% CI 0.30–0.80), p = 0.004). Significantly reduced rate of respiratory-related hospitalization (but not all-cause mortality) was also observed among those with > = 1 respiratory-related hospitalization (HR 0.38, 95% CI 0.15–0.99) and systemic corticosteroid receipt (HR 0.37, 95% CI 0.19–0.94) in the year prior to the index date, which reflect sicker subgroups of persons. Conclusions: Undergoing polysomnography was associated with significantly improved clinically-important health outcomes among individuals with IPF, highlighting the potential importance of incorporating this testing in IPF disease management.