Fig. 4From: Clinical application of headache impact test (HIT)-6 and epworth sleepiness scale (ESS) for sleep apnea headacheHIT-6 (A) and ESS (B) scores before and after treatment. CPAP (good) shows results in the good-adherence subgroup. CPAP (poor) shows results in poor-adherence subgroup. *p < 0.05 and **p < 0.01 based on the Wilcoxon signed-rank test. The effect size of the results with p < 0.01 was at least 0.55, indicating large effect size.Back to article page