(422) Circadian Rhythm, Sleep Quality, and Acceptability of Cognitive Training in Older ICU Survivors

Introduction: Circadian dysrhythmia (disturbances to the circadian rhythm) is observed in about 75-80% of ICU patients. Together, circadian dysrhythmia and sleep quality are risk factors for ICU delirium and may decrease the efficacy of interventions to prevent cognitive decline in high-risk older ICU survivors.

Methods: This is a preliminary, descriptive, secondary data analysis of an ongoing pilot intervention study to explore the potential roles of individual chronotype and sleep quality on acceptability of computerized cognitive training in hospitalized older ICU survivors. Data from the first 14 participants were analyzed. Participants were randomized to one of 3 groups: 1) morning cognitive training sessions [COG-AM]; 2) afternoon cognitive training sessions [COG-PM]; or 3) standard care. Chronotype was measured by the reduced Composite Scale of Morningness. Circadian rhythm was characterized utilizing iButton wearable sensors to record continuous body temperature. Intervention adherence rates were calculated by group. Sleep quality was assessed by the PROMIS Sleep Disturbance and Sleep-Related Impairment instruments. Preliminary feedback on acceptability was collected via surveys. Descriptive analyses explored possible trends between circadian rhythm, sleep quality, adherence, and acceptability.

Results: The majority of participants (64.3%) were classified as morning chronotype. An overall higher adherence rate was observed in the COG-AM group (87.5%) compared to the COG-PM group (38.8%). The mean temperature amplitude was 1.9 degrees Celsius. There was a positive, non-significant correlation between mean temperature amplitude and adherence rate [r(5) = 0.56, p = 0.19]. Participants who reported worse sleep-related impairment also tended to perceive that cognitive training was helpful to them [r(5) = 0.78, p = 0.037] and would recommend cognitive training to other older ICU survivors [r(5) = 0.79, p = 0.034].

Conclusions: Interventions should be personalized to encourage older ICU survivors to continue participation in cognitive training throughout recovery. Chronotherapeutic timing of cognitive interventions to the patient’s individual chronotype may be a potential method to mitigate the effects of circadian dysrhythmia and poor sleep quality.