J Clin Sleep Med. 2025 Jul 1. doi: 10.5664/jcsm.11804. Online ahead of print.ABSTRACTSTUDY OBJECTIVES: To determine the role of sleep-disordered breathing (SDB), insomnia symptoms and sleep quality in the daytime function and quality of life of veterans with spinal cord injury (SCI).METHODS: This cross-sectional cohort study took place in a Veterans Administration (VA) medical center in the Midwestern US. Thirty-eight male veterans with SCI (22 cervical, 16 thoracic; mean [SD] age = 62.9[9.5] years) completed baseline assessments within a larger clinical trial. Measures assessed sleep apnea severity (apnea-hypopnea index, AHI), insomnia symptoms (Insomnia Severity Index, ISI), self-reported sleep quality (Pittsburg Sleep Quality Index, PSQI), daytime sleepiness (Epworth Sleepiness Scale, ESS), fatigue (Flinders Fatigue Scale, FFS), depression (Patient Health Questionnaire-9 item, PHQ-9 excluding sleep item), functioning (Spinal Cord Independence Measure, SCIM), and quality of life (World Health Organization Quality of Life, WHOQOL-BREF). Bivariate correlations (alpha p