sleep efficiency
Percentage of time spent asleep while in bed, calculated as total sleep time divided by time in bed multiplied by 100.
Full Definition
Sleep efficiency is a key polysomnographic parameter that measures sleep quality by calculating the percentage of time actually spent sleeping out of the total time spent in bed. Normal sleep efficiency is typically 85% or higher in healthy adults. The calculation involves dividing total sleep time by total time in bed (from lights out to final awakening) and multiplying by 100. Reduced sleep efficiency may indicate sleep initiation difficulties, frequent awakenings, early morning awakening, or underlying sleep disorders. Sleep efficiency is an important outcome measure for evaluating sleep interventions and treatment responses.
Usage
Usage note: Express as a percentage. Values below 85% are generally considered abnormal in adults.
In Context
- "The patient's sleep efficiency improved from 65% to 88% after CPAP therapy initiation." — Treatment outcome assessment
- "Sleep efficiency of 72% indicated significant sleep maintenance difficulties." — Sleep study interpretation