Comparison of ArI between females and males during NREM and REM sleep as categorized by our sex-specific models M2 (NREM female) (A), M3 (NREM male) (B), M5 (REM female) (C), and M6 (REM male) (D). Mean and comparison intervals are indicated as circles and horizontal lines, respectively. F statistics and P indicate the test statistics and the significance level of one-way ANOVA testing between groups. An overlap between the comparison intervals and P > .05 indicates that the means of the two groups are not statistically significant; for significance, the two intervals should remain disjointed with P < .05. AHI = apnea-hypopnea index, ANOVA = analysis of variance, ArI = arousal index, NREM = non-rapid eye movement, REM = rapid eye movement.