Chronotype in relation to shift work: A cohort study among 37,731 female nurses.

Chronotype may affect tolerance for circadian disruption induced by shift work. This study examines the association between chronotype, self-reported sleep timing, shift type preference, and sleep problems among nurses, and studies chronotype stability over time. The study included 37,731 Dutch female nurses who completed a baseline (2011) and follow-up questionnaire (2017), with information on shift work (e.

Single-item chronotype is associated with dim light melatonin onset in lymphoma survivors with fatigue.

Chronotype is frequently assessed in human observational studies using various morningness-eveningness questionnaires. An alternative single-item chronotype question has been proposed for its reduced administration time and its accessibility to all types of populations. We investigated whether this single-item chronotype is associated with dim light melatonin onset, the "gold standard" for estimating the endogenous circadian phase.