Association between PSQI and composite endpoints in ALS patients: a retrospective cohort study from China
Abstract
Sleep disturbance is common in patients with amyotrophic lateral sclerosis (ALS), but its association with severe clinical outcomes remains insufficiently characterized. We aimed to investigate the association between baseline sleep quality, assessed using the Pittsburgh Sleep Quality Index (PSQI), and the risk of tracheostomy or all-cause death in patients with ALS. This retrospective cohort study used a non-public institutional ALS registry to identify patients treated between January 2019 and May 2022. The primary outcome was a composite endpoint of tracheostomy or all-cause mortality, whichever occurred first. Kaplan-Meier curves, Cox proportional hazards models, restricted cubic spline analyses, subgroup analyses, and sensitivity analyses were used to evaluate the association between PSQI score and clinical outcomes. Multivariable models adjusted for age, sex, household income, site of onset, forced vital capacity, ALSFRS-R total score, disease progression rate, body mass index, albumin, and HDRS score. A total of 268 patients with ALS were included, of whom 115 experienced a composite endpoint event during follow-up. In the fully adjusted model, each 1-point increase in PSQI score was associated with a 13% higher risk of tracheostomy or death (HR = 1.13, 95% CI: 1.07–1.20, P < 0.001). Compared with patients without sleep disturbance, those with moderate-to-severe sleep disturbance had a significantly higher risk of the composite endpoint (HR = 2.65, 95% CI: 1.55–4.53, P < 0.001), whereas mild sleep disturbance was not significantly associated with risk. Higher baseline PSQI scores were associated with an increased 36-month risk of tracheostomy or all-cause death in patients with ALS, particularly among those with moderate-to-severe sleep disturbance. These findings may support incorporating systematic sleep assessment into ALS prognostic risk stratification. However, because PSQI may partly reflect unmeasured nocturnal respiratory dysfunction or overall disease burden, the present observational data should not be interpreted as evidence that improving sleep quality will causally improve ALS outcomes.