title: Subjective and objective daytime sleepiness in schoolchildren and adolescents: results of a community-based study.
abstract: OBJECTIVE
  We aimed to assess subjective and objective sleepiness in schoolchildren and adolescents by using questionnaires and the Pupillographic Sleepiness Test (PST).
  
  
  METHODS
  An observational, cross-sectional, community-based study was performed. Participants were recruited and balanced by age and gender from schools using stratified random sampling. Sleep problems and subjective sleepiness were assessed using parent- and self-reported questionnaires. Objective sleepiness was assessed in schools under standardized conditions by using the PST and by calculating the natural logarithm of the pupillary unrest index (lnPUI).
  
  
  RESULTS
  In total 163 children (82 boys; age range, 6.6-17.8 years) were enrolled. Age and sleep problems were predictors of subjective sleepiness. Nine PST recordings (5.5%) were excluded due to artifacts (feasibility, 94%). Gender, sleep problems, and sleep duration were predictors of objective sleepiness. Compared to adults (age range, 20-60 years), the lnPUI was higher in children (mean±standard deviation [SD], 1.5±0.4 vs. 2.0±0.4; P<.001) and showed significant gender differences. There was no agreement between measures of subjective sleepiness and the lnPUI (r<0.3). After excluding children with sleep problems, preliminary reference values (mean±SD) for the lnPUI were 2.01±0.43 for boys and 1.93±0.43 for girls, respectively.
  
  
  CONCLUSIONS
  The PST is a feasible method in schoolchildren and adolescents. Sleep problems are predictors of both subjective and objective sleepiness; there is no agreement between the latter. Results of the PST are influenced by sleep duration and specific pediatric gender-stratified reference values are definitively needed.
authors.affiliation: Unit of Pediatric Epidemiology, Institute of Medical Biostatistics, Epidemiology, and Informatics, University Medical Center, Mainz, Germany; Working Group on Pediatric Sleep Medicine, Department of Neonatology, University Children's Hospital, Tuebingen, Germany. Electronic address: urschitz@uni-mainz.de.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Urschitz
authors.forename: Katrin
authors.initials: K
authors.lastname: Heine
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Brockmann
authors.forename: Tobias
authors.initials: T
authors.lastname: Peters
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Durst
authors.forename: Christian F
authors.initials: CF
authors.lastname: Poets
authors.forename: Barbara
authors.initials: B
authors.lastname: Wilhelm
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D003430:Cross-Sectional Studies; D006970:Disorders of Excessive Somnolence / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D010290:Parents; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012111:Residence Characteristics; D012574:Schools; D057566:Self Report / Q000592:standards; D012894:Sleep Stages; D013334:Students / Q000523:psychology / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires / Q000592:standards
keywords: Alertness; Central nervous activation; Children; Hypersomnia; Pupillography; Sleep