Criteria for self-reported quantitative sleep characteristics of individuals who sought medical help for disturbed sleep - a survey of a representative sample of the Swedish population.

Background: The public often seeks rule-of-thumb criteria for good or poor sleep, with a particular emphasis on sleep duration, sleep latency, and the number of awakenings each night. However, very few criteria are available.

Aim: The present study sought to identify such criteria.

Methods: Whether or not a person has sought medical help for sleep problems was selected as an indicator of poor sleep. The group that was studied constituted a representative sample of the general Swedish population (N=1,128), with a response rate of 72.8%.

Results: Logistic regression analysis, with an adjustment for age and gender, showed an increased OR for a weekday sleep duration of ≤6 hour, (OR >2, and for <5 hour: OR >6). For weekend sleep, the value was ≤6 hour (OR >2). For awakenings per night, the critical value was ≥2 (OR >2, and for ≥5 awakenings: OR >9), and for a sleep latency the critical value was ≥30 minutes (OR >2, and for ≥45 minutes: OR >6). Adding difficulties falling asleep and early morning awakening (considered qualitative because of the reflected "difficulty"), led to the elimination of all the quantitative variables, except for the number of awakenings. The addition of "negative effects on daytime functioning" and "sleep being a big problem" resulted in the elimination of all the other predictors except age.

Conclusion: It was concluded that weekday sleep ≤6 hour, ≥2 awakenings/night, and a sleep latency of ≥30 minutes, can function as criteria for poor sleep, but that qualitative sleep variables take over the role of quantitative ones, probably because they represent the integration of quantitative indicators of sleep.