Measuring sleep in the intensive care unit: Electroencephalogram, actigraphy, or questionnaire?

Background Studies consistently report deranged sleep in patients admitted to intensive care unit. Poor sleep has harmful physical and cognitive effects, and an evidence-based intervention to improve sleep is needed. It is, however, difficult to measure sleep in the intensive care unit. ‘Gold standard’ monitoring (polysomnography) is unsuitable for usual care. Methods We collected concurrent sleep data from electroencephalograph recordings, activity monitoring, and nurse- and patient-completed Richards-Campbell Sleep Questionnaires (RCSQ). Results Electroencephalograph data (n = 34) confirm poor sleep. Individual bouts last approximately 1 min and around 2 h of sleep overnight is common. Correlation between electroencephalograph, self-report, nurse-report, actigraphy and overall activity score is low (ρ = 0.123 (n = 24), 0.127 (n = 22), and 0.402 and − 0.201 (n = 13), respectively). Correlation between nurse and patient assessment is limited (ρ = 0.537 (n = 444)). Conclusions No current method of sleep monitoring seems suitable in the intensive care unit. However, to facilitate comparison across studies, the patient-completed RCSQ seems the most meaningful measure.