Sleep Regularity Index After Stroke: Change Over Time and Its Association with Recovery

BackgroundSleep-wake disruption is common after stroke and may impede recovery. The Sleep Regularity Index (SRI) quantifies the probability that a person is in the same sleep or wake state at the same clock time on consecutive days. This study evaluates SRI during post-stroke recovery, estimating associations with stroke outcomes, and characterizing transitions between SRI states over time. MethodsWe analyzed data from 71 participants that were part of a larger on-going study exploring the impact of non-OSA sleep disorders post stroke. Data were collected at 10, 60, and 90 days post stroke. SRI was calculated from sleep-wake data that was collected from wrist worn actigraphy. Covariates included time, National Institutes of Health Stroke Scale (NIHSS), Stroke Impact Scale (SIS), steps/day, sedentary time/day, and Patient Health Questionnaire 9. Associations between SRI and covariates were estimated using generalized estimating equations. A logistic regression model was used to assess whether clinical variables were associated SRI improvement at 60 days. ResultsSRI was low at 10 days post stroke (32.68) and did not significantly change at 60 (34.01, p=0.98) or 90 (38.44, p=0.57) days post stroke. SRI was significantly associated with NIHSS (p=0.04) and SIS (p=0.02). Improvement in SRI was significantly associated with NIHSS (p=0.03). ConclusionsThis is the first study that we are aware of to investigate sleep regularity early after stroke. We found that sleep regularity was associated with QOL and stroke severity, and that sleep regularity did not improve after discharge from the hospital. Clinical Trial Registration: NCT05012605.