Figure 2

The RMSE outcomes between subjective SOL and LPS. The x-axis represents the length of non-awake time (min). The y-axis represents the RMSE. (A) For all participants (n = 149), the optimal length of non-awake time was 12 min. (B) For participants with subjective insomnia (n = 120), the optimal length of non-awake time was 13 min. (C) For participants without subjective insomnia (n = 29), the optimal length of non-awake time was 8.5 min. (D) For participants with subjective insomnia and difficulty in falling asleep (n = 54), the optimal length of non-awake time was 13–13.5 min. (E) For participants with subjective insomnia but no difficulty in falling asleep (n = 66), the optimal length of non-awake time was 13 min. (F) For participants with subjective insomnia and moderate or severe OSA (n = 37), the optimal length of non-awake time was 19.5 min. (G) For participants with subjective insomnia and no OSA (n = 83), the optimal length of non-awake time was 10 min. RMSE root mean square error, SOL sleep onset latency, OSA obstructive sleep apnea, TST total sleep time, SOL sleep onset latency, WASO wake after sleep onset, AHI apnea hypopnea index, PSQI Pittsburgh Sleep Quality Index, OSA obstructive sleep apnea, PLMD periodic limb movement disorders, RBD rapid eye movement sleep behavior disorders, RLS restless legs syndrome, PLMI periodic leg movement during sleep index, PSG polysomnography, CPAP continuous positive airway pressure, RMSE root mean square error, REM rapid eye movement, LPS latency to persistent sleep, IQR interquartile range.