Certification in Clinical Sleep Health (CCSH) Practice Exam

Wake After Sleep Onset describes the amount of time a person is awake after they have fallen asleep, during the main sleep period, up until the final morning wake time. This measure reflects sleep continuity: more time awake after sleep onset means more fragmented sleep and usually lower sleep efficiency. It is typically recorded during sleep studies or with actigraphy. The other terms do not relate to this sleep metric—ventricular tachycardia and ventricular tachyarrhythmia are cardiac rhythm disorders, and Wake After Sleep Offset would refer to time awake after the final morning awakening, not after sleep onset.