Figure 3
From: A novel method to visualise and quantify circadian misalignment
Composite Phase Deviations in day workers.
Panel a shows individual density plots sorted by chronotype (see MSFsc above each plot). For comparison, cut-off values for chronotype categories ‘early’ (n = 8, MSFsc < 3:53) and ‘late’ (n = 2, MSFsc > 5:36) are the same as for the shift workers shown in Fig. 2. Note that sleep times are based on sleep log data in the day worker sample. The sleep-wake behaviour of four individuals are displayed in more detail in panels b–e: double-plotted sleep times (black bars; white vertical line: MSFsc) and work times (light blue bars) over the course of 5 weeks are shown on the left of each panel, and the corresponding mid-sleep profiles (x-axis: days, y-axis: mid-sleep, dotted line: MSFsc) and Δplots (x-axis: ΔREF, y-axis: ΔDD) on the right. Panel f sorts the density plots of panel a according to chronotype (x-axis) and work start time (y-axis; one day worker – MSFsc = 4:07 – was excluded due to missing work-time information). Grey-scale coding reflects average CPD values based on a quartile split (white: 0–1.15, striped: 1.16–1.50, light grey: 1.51–2.00, dark grey: 2.01–2.70). Results of the mixed effects regression model are graphed in panel g using a surface plot illustrating a three-way interaction effect between start and variability of work times, and chronotype. Variability is assessed as the standard deviation (sd, in h) of work start times within each individual. Colour coding reflects average CPD values in 1 h bins (yellow: 0–1, dark red: 6.01–7). Note that ΔReference in these examples refers to the difference between a given mid-sleep and the individual chronotype (MSFsc); the latter is used as the reference measure but can be replaced by other variables assumed to reflect an optimum.
