Measuring and Predicting Inter-Individual Variability in Circadian Response to Shift Work

Shift work is highly prevalent and is associated with numerous adverse health outcomes. There is considerable inter-individual variability in how the circadian clock responds to rotating shifts, although the mechanisms are not well understood. This thesis identifies light-dark exposure and diurnal preference as key explanatory variables underlying inter-individual variability in circadian response to shift work. Furthermore, the generalisability of practical methods for estimating circadian timing in ambulatory conditions using light, activity, and skin temperature is evaluated in a shift work population for the first time. These findings will inform development of personalised approaches to managing circadian disruption among shift workers.