Post-discharge insomnia symptoms are associated with quality of life impairment among survivors of acute lung injury

Introduction: Sleep disturbance is common during critical illness, yet little is known about its prevalence or role in post-discharge quality of life among high-risk acute lung injury (ALI) patients. Methods: In a prospective cohort of 61 mechanically ventilated ALI patients, we examined the association between insomnia symptoms and quality of life six months after discharge. Subjects completed surveys rating quality of life (MOS SF-36), post-traumatic stress disorder (PCL), and depression (PHQ-9). Using an individual item from the PCL, we defined insomnia symptoms as moderate or greater trouble falling or staying asleep in the past month. We performed multivariable linear regression to examine the association between insomnia symptoms and SF-36 physical and mental component summary scores, adjusting for PTSD and depression. Results: Forty subjects (85% of eligible) completed six-month questionnaires; 20 (50%) met criteria for insomnia symptoms. After adjustment for PTSD and depression, insomnia symptoms remained significantly associated with worse physical component summary scores (adjusted mean difference = -8.8; 95% CI: -15.0, -2.5; P<. 0.01). Conclusions: Post-discharge insomnia symptoms were common and significantly associated with physical quality of life impairment among six-month ALI survivors, even after adjustment for PTSD and depression symptoms. Further studies are needed to validate these results and to characterize sleep disturbance after ALI using sleep-specific metrics.