Figure 5. Predicted vs. actual phase shift for each participant from two models.

A, phase shift predictions calculated using regression model incorporating the difference between light in the delay and advance zones at baseline, and averaged across the night shifts; B, phase shift predictions calculated using a regression model using the difference between the delay and advance zones at baseline, averaged across the night shifts, and MEQ score. Predictions using this model (B) show less prediction error compared to predictions obtained without including MEQ score (A). Filled symbols indicate actual phase shift; open symbols indicate predicted phase shift. Men are represented by triangles, women by circles. Negative phase shift = phase delay, positive = phase advance. Participants are ranked according to their phase shift.