Subjective daytime sleepiness and its predictors in Finnish adolescents in an interview study

The purpose of this study is to evaluate the predictors of subjective daytime sleepiness (SDS) and its chronicity in adolescents. Two groups of adolescents (107 with SDS and 107 without SDS) from our first questionnaire study were invited to an interview after 3 y. A follow-up questionnaire had been sent to them one year earlier. The interview included questions about sleep, daytime sleepiness, living habits, physical and mental health, and progress at school. The adolescents were also examined clinically. Interviews were conducted with 66 out of 107 subjects with SDS and 64 out of 107 without SDS (age range 12 to 19 y). In this interview 42 out of the 130 adolescents had SDS. A total of 20 adolescents reported SDS in both questionnaire studies and in the interview (chronic SDS). In a multivariate analysis (logistic regression) sleep disorders, frequent medication and depressive emotions were significantly associated with SDS. Chronic SDS was connected in a bivariate analysis (Pearson's chi-square) with excessive night waking, difficulty in falling asleep, dreaming, frequent medication, frequent alcohol drinking, and irregular breakfast eating, and in our previous studies also with delayed sleep rhythm.

Sleep disorders and health problems were more common causes of SDS than undesirable living habits. However, alcohol drinking and delayed sleep rhythm were associated with chronic SDS in addition to sleep disorders and medication.