Response to Letter to the Editor: Poststroke Fatigue at Admission is Associated With Independence Levels of Activities of Daily Living at Discharge From Subacute Rehabilitation Wards

We would like to thank the authors of the letter to the editor related to our article. They suggested considering the effects of sleep disorders on functional outcome, given that sleep disorders are frequently observed in patients with stroke and patients with sleep disorders sometimes complain of fatigue instead of sleepiness. We completely agree with the importance of assessing sleep disorders because patients with stroke can lack symptoms of sleep-disordered breathing (SDB). Regarding this context, we previously investigated the prevalence of SDB using a portable sleep-monitoring device and the effect of SDB on functional outcome in patients with stroke (n=433) in rehabilitation wards. The study revealed a high prevalence of SDB: 87.3% of the patients had a respiratory event index (REI) of ≥5 events/h, and 46.4% had an REI of ≥15 events/h. Excessive daytime sleepiness assessed based on an Epworth Sleepiness Scale score of ≥11 was observed in only 5.2% of patients, suggesting that most patients with SDB did not have self-reported symptoms, as reported previously. Although functional outcomes were significantly poorer in patients with SDB than in those without SDB, we found that REI was not a significant independent factor for functional outcome at discharge when adjusted for potential confounders including baseline functional status. The study highlighted the need to revisit the question of whether SDB is associated with functional outcome in patients with stroke in rehabilitation wards. Therefore, we did not include SDB in our analyses.