Sleep habits, perceived sleep quality and tiredness among adolescents : a health behavioural approach

Abstract

The aim of the present study was to investigate 11, 13 and 15-year-old adolescents' sleep habits, sleep difficulties, perceived tiredness, perceived sleep quality and factors affecting them. This study is part of a larger, comparative, WHO-coordinated project on the health and lifestyle of school children (Health Behaviour of School Aged Children - A WHO Cross-National Survey, the HBSC-Study). International data (n=41,809) from the 1986 HBSC-Study and Finnish data from the 1990 (n=2,996) and 1994 (n=4,187) HBSC-Study were used in this thesis. Another aim was to test scales for the measurement of perceived alertness and sleep quality among 15-year-olds in the Jyvaskyla follow-up study in 1996-97 (n=475, 202 of whom were 15-year-olds). The studies were class inquiries where pupils answered a questionnaire during a class period. Basic statistical methods such as crosstabulations, Pearson product moment correlations, analysis of variance as well as more sophisticated methods like logit-regression analyses and structural equation models in the framework of LISREL were used. International comparisons in the 1986 HBSC-Study indicated that sleeping habits, difficulty in falling asleep and morning tiredness varied significantly between countries. Finnish school children had the second shortest sleep duration at night after the Israeli youth and together with Norwegian school children they were most tired on school mornings. Investigation of the Finnish data in the 1990 HBSC-Study revealed that unhealthy (irregular) sleeping habits, sleep difficulties and tiredness emerged with increasing age. Age and in some cases gender were important explanatory factors of sleeping habits and sleep difficulties. Other sociodemographic factors or pupils' educational expectations (high school vs. occupational school) were far less correlated or did not correlate with sleep habits and sleep difficulties. The Finnish data of the 1994 HBSC-Study revealed that subjective tiredness was a very common phenomenon among adolescents. Structural equation models among 15-year-olds showed that sleep habits, use of psychoactive substances (mainly alcohol and tobacco) and perceived tiredness were statistically significantly correlated. Among 15-year-old boys a good home atmosphere was the most important contributing factor to good perceived sleep quality. A health promotive lifestyle (good sleep hygiene and infrequent use of addictive substances) and good self-perception also had significant correlations with good perceived sleep quality. In 15-year-old girls a good home atmosphere, good self-perception and a health promotive lifestyle played an equally important role in associations with subjective sleep quality. The results of the Jyvaskyla follow-up study indicated that the scales for perceived alertness and sleep quality had good internal consistency and that the confirmatory factor models seemed to be rather independent of the time of data collection. It is recommended that the scales be tested in the school health care system in order to evaluate health promotion needs concerning school children's sleep quality and alertness.