Optimal Timing of Computerized Cognitive Training for Older Intensive Care Unit Survivors

Over 60% of intensive care unit (ICU) patients are older adults (ages 60 and older). Up to 40% of ICU survivors experience cognitive impairment that is comparable in severity to moderate traumatic brain injury, while 25% have symptoms similar to mild Alzheimer's disease after hospital discharge. Older ICU survivors are at high risk for ICU-acquired cognitive impairment, often leading to a protracted recovery in a care facility. Several factors, including circadian misalignment (observed in about 75-80% of ICU patients), may decrease effects of interventions designed to improve cognitive function. Further, daytime activity is essential for recovery from critical illness and to promote circadian realignment, yet ICU survivors experience profound inactivity. The scientific premise of the proposed research is that identifying the optimal circadian timing of cognitive interventions for older ICU survivors may improve intervention feasibility, acceptability, and efficacy. Interventions targeting symptoms (i.e., disturbances in circadian rhythm and cognitive impairment) may deliver similar outcomes across conditions that require ICU admission (e.g., cancer, heart failure, pneumonia, hip fracture). To date, interventions have not been evaluated in older ICU survivors that simultaneously target circadian misalignment and cognitive impairment. Moreover, because circadian misalignment adversely affects cognitive function, understanding the optimal timing of cognitive interventions is crucial to promote both circadian realignment and cognitive function. Specific Aim 1 will determine feasibility, acceptability, and preliminary effect sizes for: 1) a morning session of a computerized cognitive training intervention [COG]; and 2) a late afternoon/early evening session of the COG intervention; compared to 3) standard inpatient care/usual care [UC]. Specific Aim 2 will examine circadian rhythm parameters to determine the optimal timing of the daily COG intervention. Exploratory Aim 3 will explore if the effects of the COG intervention on cognitive function are mediated by daytime activity, and explore if selected biological and clinical factors moderate intervention effects on cognitive function. The proposed early-stage clinical trial will be the first to evaluate chronotherapeutic timing of a computerized cognitive training intervention for hospitalized older ICU survivors after ICU discharge, to initiate early cognitive recovery on a post-ICU unit.