Abstract
OBJECTIVES: Studies have reported bidirectional associations of sleep with daily stressors and negative mood. Yet we know little about how sleep is associated with workers' daily cognitive interference, or the experience of off-task and distracting thoughts. This study examined whether nightly sleep was associated with next-day cognitive interference, and vice versa, during workdays and non-work days. DESIGN: Daily telephone interviews. SETTING: US information technology workplaces. PARTICIPANTS: 130 middle-aged employees. MEASUREMENTS: On 8 consecutive days, participants reported the frequency of experiencing off-task and distracting thoughts during the day (0 = never to 4 = very often) and multiple sleep characteristics (bedtimes, wake times, sleep duration, sleep quality, and sleep latency). Covariates included sociodemographic characteristics and work hours. RESULTS: Multilevel models revealed that, on days following earlier wake times (B = -0.32, P < .01), shorter sleep duration (B = -0.27, P < .01), or poorer sleep quality (B = -0.17, P < .01), participants reported more cognitive interference than usual. That is, waking 19 minutes earlier and sleeping 16 minutes less were associated with one additional point on the cognitive interference scale the next day. With cognitive interference predicting nightly sleep, more same day's cognitive interference was associated with earlier bedtimes (B = -0.19, P < .05) and earlier wake times (B = -0.30, P < .01) than usual. The temporal associations of nightly sleep duration and sleep quality with the following day's cognitive interference were significant on work days, but not on non-work days. CONCLUSION: Our results suggest bidirectional associations between poorer sleep and more cognitive interference, particularly on work days with implications for workday productivity and quality of life.