How is Sleep Efficiency Index (SEI) calculated?

How is Sleep Efficiency Index (SEI) calculated?

• A. TRT / TST × 100
• B. TST / TRT × 100
• C. W / TST × 100
• D. TST / WASO × 100

Answer: (B)

Sleep Efficiency Index shows how much of the recording time is spent actually sleeping. It is calculated by dividing Total Sleep Time by Total Recording Time and multiplying by 100 to give a percentage. In symbols, SEI = TST / TRT × 100, where TST is the total minutes asleep and TRT is the total minutes recorded (from lights on to lights off). For example, if you slept 360 minutes during an 8-hour (480-minute) recording, SEI = 360/480 × 100 = 75%. A higher SEI means sleep was more consolidated within the recording period.

Sleep Efficiency Index shows how much of the recording time is spent actually sleeping. It is calculated by dividing Total Sleep Time by Total Recording Time and multiplying by 100 to give a percentage. In symbols, SEI = TST / TRT × 100, where TST is the total minutes asleep and TRT is the total minutes recorded (from lights on to lights off).

For example, if you slept 360 minutes during an 8-hour (480-minute) recording, SEI = 360/480 × 100 = 75%. A higher SEI means sleep was more consolidated within the recording period.