Fig. 1. Illustration of computations of mean salivary cortisol level and slope of diurnal change in cortisol using log-transformed cortisol values. Top, Values for raw salivary cortisol for each time point across the 3 days of sampling. Bottom, Log-transformed cortisol values. Mean cortisol level was assessed by summing across all 12 points and computing a mean; line represents diurnal variability or slope of the diurnal curve, calculated by regressing cortisol values on the time of day collected.
