Background: Sleep is an important factor in the physical and mental health and everyday functioning of adolescents. During this developmental period, biological changes, a shift in the circadian rhythm, academic demands, and many social and behavioural changes increase the risk of insufficient and lower-quality sleep. Comprehensive monitoring of adolescent sleep in Slovenia has thus far been limited by the lack of culturally adapted and psychometrically validated measurement instruments.
Aim: The aim of this doctoral dissertation was to develop, culturally adapt, and psychometrically evaluate a Slovenian battery of questionnaires for assessing sleep hygiene, sleep quality, excessive daytime sleepiness, and chronotype in adolescents. Additionally, we sought to assess the prevalence of sleep problems among Slovenian adolescents and examine the associations between sleep indicators and biological, psychological, social, and environmental factors.
Methods: The study was conducted in several phases. In the first phase, internationally established questionnaires were translated, culturally adapted, and content-validated by a heterogeneous group of 11 experts. In the second phase, a nationwide cross-sectional study was conducted among eighth-grade primary school students and first- and third-year secondary school students. The final sample comprised 3,314 adolescents aged 12 to 19 years (M = 15.43; SD = 1.65), of whom 51.51% were girls. The Adolescent Sleep Hygiene Scale, the long and short versions of the Adolescent Sleep–Wake Scale, the Pediatric Daytime Sleepiness Scale, the Epworth Sleepiness Scale for Children and Adolescents, and the Morningness–Eveningness Scale for Children were used. Psychometric properties were examined using reliability and construct validity analyses, exploratory and confirmatory factor analyses, and measurement invariance analyses; regression models were additionally used to identify predictors of the sleep indicators under investigation. In the third phase, a subgroup of 26 adolescents also underwent multi-day sleep monitoring using actigraphy.
Results: In the first phase of the study, the expert group confirmed the content validity of the developed questionnaire battery, and the necessary linguistic and cultural adaptations of individual items were made based on assessments of clarity, relevance, and factorial validity. In the second phase, psychometric analyses also confirmed adequate reliability, construct validity, and comparability of the Slovenian versions of the instruments with the original instruments, thereby establishing a methodological basis for the comprehensive assessment of different sleep indicators among Slovenian adolescents. The results of the nationwide study showed that inadequate sleep habits, poorer sleep quality, and excessive daytime sleepiness were present among adolescents, although only a small proportion reported diagnosed sleep disorders. Psychological burdens among adolescents emerged as one of the most important risk factors for adverse sleep outcomes. Individual sleep indicators were additionally associated with the use of electronic devices before bedtime, late-night studying, daytime napping, and the consumption of caffeine, energy drinks, nicotine, and alcohol. In the third phase, sleep monitoring using actimeters showed substantial variability in sleep patterns among individuals of different ages, as well as differences between school days and days off. Insufficient sleep duration or poorer sleep consolidation was identified in a substantial proportion of adolescents. The findings from all three phases therefore confirm that adolescent sleep is a multidimensional phenomenon that cannot be adequately explained by a single risk factor.
Conclusion: The study established a methodological basis for the standardised and multidimensional assessment of sleep among Slovenian adolescents and demonstrated that their sleep cannot be explained by a single factor. The findings support the use of the developed questionnaire battery in future research and in the monitoring of adolescent health, as well as the early identification of at-risk groups and the development of multicomponent preventive interventions in healthcare, educational, and family settings.
|
