Sleep latency versus shuteye latency: Prevalence, predictors and relation to insomnia symptoms in a representative sample of adults.

Shuteye latency (SEL) refers to the time spent performing activities in bed before attempting sleep. This study investigates (a) the prevalence, duration and predictors of SEL, (b) its association with insomnia symptoms (sleep onset latency [SOL], sleep quality and fatigue), and (c) the activities engaged in during SEL. A representative sample of 584 adults (18-96 years old) participated in an online survey. Respondents reported their SEL on weekday nights (Sunday to Thursday) and weekend nights (Friday and Saturday), and activities during SEL. One in five adults tried to sleep immediately at bedtime. Around 16% of respondents were awake >30 min on both weekday and weekend nights. Younger people and those with an eveningness preference reported longer SEL. Longer SEL corresponded with a progressive decline in sleep quality, increased SOL and more fatigue. Those with an SEL >30 min reported using both passive (e.g. television) and interactive (e.g. smartphone) media more frequently than respondents with an SEL < 30 min, but there was no difference between the groups for non-screen-related activities. Implications of SEL for measurements commonly used in sleep research are discussed. Shuteye latency may be symptomatic of how a modern lifestyle puts increasing pressure on sleep, but may also reveal a previously undocumented behaviour associated with insomnia symptoms.