Figure 6. Diurnal variation in salivary cortisol for the firefighter case series.

Box plot showing the diurnal variation in cortisol concentrations found in the saliva of the study subjects measured twice daily at 08:00 and 20:00 during the same 72-hour work shift. The lengths of each box indicate the 95% confidence intervals. Within each box, horizontal lines indicate the medians, x’s connected by lines indicate the means. Bars extending from each box indicate the maximum and minimum values. Markers indicate pairwise comparisons significantly different at P< 0.05.