Figure 1From: Diurnal variation of tension-type headache intensity and exacerbation: An investigation using computerized ecological momentary assessmentDiurnal variation in headache intensity. The estimated mean headache intensity is shown with its standard error for each three-hour block. a P < 0.05 vs. 3:00-6:00; b P < 0.05 vs. 6:00-9:00, using Tukey's multiple comparison.Back to article page