Subjective cognitive abilities correlate with poor sleep among day-shift and night-shift nurses.

Experimental studies have shown that sleep deprivation may lead to worse performance on cognitive tests. However, few studies have considered how sleep is associated with perceived cognitive performance in the daily lives of hospital nurses who require high cognitive abilities to deliver high-quality patient care. The current study examined the relationship between sleep and subjective cognition in nurses, and whether the relationship differed by work shift and workdays. Sixty in patient nurses working full-time (M = 35 years; 39 day-shift nurses, 21 night-shift nurses) reported their sleep characteristics and daily subjective cognition using ecological momentary assessment for 14 days. Concurrently, objective sleep characteristics were measured with a sleep actigraphy device for 14 days. Using multilevel modelling, results indicated that at the within-person and between-person level, better sleep quality and higher sleep sufficiency were associated with better subjective cognition at the daily-level and on average. Moderation analyses indicated at the within-person level, better sleep quality and longer time in bed were associated with better next-day cognition; these associations were stronger for night-shift nurses compared with day-shift nurses. At the between-person level, better sleep quality and higher sleep sufficiency were also associated with better subjective cognition overall; these associations were significant for day-shift nurses, but not for night-shift nurses. The sleep-subjective cognition relationships were more apparent on workdays versus non-workdays. Findings suggest that sufficient sleep recovery is important for nurses' reports of daily and overall cognitive functioning. Night-shift nurses' subjective cognitive abilities may be more protected on days following better sleepquality and more sufficient sleep.