Table 1.

Stanford sleepiness scale and it's adaptation for the study used in the TRIP study.

Stanford sleepiness scale	Sleepiness scale used in the TRIP study
1. Felt active, wide awake	Level 1: Felt active, wide awake
2. Was functioning at a high level but not at peak	Level 2: Relaxed and awake but not fully alert
3. Felt relaxed, awake but not fully alert, responsive
4. Felt a little foggy headed	Level 3: Difficulty staying awake, was beginning to lose track
5. Felt foggy headed, had difficulty staying awake, was beginning to lose track
6. Felt sleepy, would have preferred to lie down, woozy	Level 4: Felt sleepy, would have preferred to lie down.
7. Could not stay awake, sleep onset imminent