Description

The Karolinska Sleepiness Scale measures the subjective level of sleepiness at a particular time during the day. On this scale, subjects indicate a level which best reflects the psycho-physical state experienced in the last 10 minutes. The KSS is a measure of situational sleepiness.

Practical Application

KSS has been used in studies of shift work, jet lag, attention and performance and in clinical settings. It is helpful in assessing the changes in response to environmental factors, circadian rhythm, and effects of drugs/medication. The use of KSS is subjective but has been found to be highly correlated to electroencephalogram (EEG) and behavioural variables.

Scoring

Scoring of KSS is on a 9 point scale: