This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
The Epwoh scale is used for assessing: 
Select and explain. 
A. Body mass index, B. Vital capacity in Post operative patients, C. Sleep apnea, D. Risk of embolism in perioperative patient
C: Sleep apnea
Answer: C: Sleep apnea 
Explanation: The Epwoh Sleepiness Scale (ESS) and the STOP-Bang questionnaires have not been validated in outpatient primary care settings but are quick and easy to use. The ESS measures daytime sleepiness, with a score of >=10 indentifying individuals who warrant additional investigation scale. Ref Harrison 19th edition pg 1721