On-Call Work and Sleep: Why Waiting

Why can being on call disrupt sleep without a phone call?

Sleep requires more than lying in bed: it also depends on feeling sufficiently safe and disengaged to reduce alertness. When workers expect that a ringtone could require an immediate decision, journey or clinical response, they may continue monitoring the environment rather than fully detaching from work. This anticipatory state may delay sleep, increase awakenings or make sleep feel less restorative even if no call arrives.

The effect is unlikely to be identical for every worker. Call frequency, responsibility, response time, control over scheduling and fear of serious consequences can all shape the burden. Researchers therefore need to distinguish time actually spent working from the psychological constraint of remaining available, while measuring both perceived sleep quality and objective features such as sleep duration and fragmentation.

What health effects can repeated on-call sleep disruption cause?

After an isolated disturbed night, people may experience sleepiness, irritability, slower reactions and reduced concentration. These effects matter in safety-sensitive occupations because fatigue can affect driving, clinical judgment and other complex tasks. The American Academy of Sleep Medicine and Sleep Research Society recommend that adults regularly obtain at least seven hours of sleep, although individual needs vary.

Chronic insufficient sleep is associated with hypertension, cardiovascular disease, metabolic disorders, depression and workplace injuries, but an association does not prove that on-call duty alone caused these outcomes. Long schedules can add another exposure: a WHO and International Labour Organization analysis linked working at least 55 hours per week with greater ischemic heart disease and stroke burden compared with standard working hours. Availability, actual hours worked and recovery time should therefore be assessed separately.

How can workers and employers protect sleep during on-call periods?

Organizations can limit consecutive on-call duties, distribute demanding shifts fairly, define which situations justify contact and provide recovery time after overnight work. Rotas should account for total workload rather than recording only the minutes spent answering calls. Backup coverage and realistic response expectations may also reduce the uncertainty that keeps workers alert.

Workers can use a distinct emergency ringtone, prepare necessary equipment before bedtime and avoid repeatedly checking messages that do not require monitoring. Alcohol is not a reliable sleep aid and can fragment sleep later in the night. Persistent insomnia, severe daytime sleepiness, near-miss accidents or difficulty staying awake while driving warrants medical or occupational health assessment; anyone who feels drowsy behind the wheel should stop driving safely.