title: Test-retest reliability of selected items of Health Behaviour in School-aged Children (HBSC) survey questionnaire in Beijing, China.
abstract: BACKGROUND
  Children's health and health behaviour are essential for their development and it is important to obtain abundant and accurate information to understand young people's health and health behaviour. The Health Behaviour in School-aged Children (HBSC) study is among the first large-scale international surveys on adolescent health through self-report questionnaires. So far, more than 40 countries in Europe and North America have been involved in the HBSC study. The purpose of this study is to assess the test-retest reliability of selected items in the Chinese version of the HBSC survey questionnaire in a sample of adolescents in Beijing, China.
  
  
  METHODS
  A sample of 95 male and female students aged 11 or 15 years old participated in a test and retest with a three weeks interval. Student Identity numbers of respondents were utilized to permit matching of test-retest questionnaires. 23 items concerning physical activity, sedentary behaviour, sleep and substance use were evaluated by using the percentage of response shifts and the single measure Intraclass Correlation Coefficients (ICC) with 95% confidence interval (CI) for all respondents and stratified by gender and age. Items on substance use were only evaluated for school children aged 15 years old.
  
  
  RESULTS
  The percentage of no response shift between test and retest varied from 32% for the item on computer use at weekends to 92% for the three items on smoking. Of all the 23 items evaluated, 6 items (26%) showed a moderate reliability, 12 items (52%) displayed a substantial reliability and 4 items (17%) indicated almost perfect reliability. No gender and age group difference of the test-retest reliability was found except for a few items on sedentary behaviour.
  
  
  CONCLUSIONS
  The overall findings of this study suggest that most selected indicators in the HBSC survey questionnaire have satisfactory test-retest reliability for the students in Beijing. Further test-retest studies in a large and diverse sample, as well as validity studies, should be considered for the future Chinese HBSC study.
authors.affiliation: Research Centre for Health Promotion, Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland. yang.liu@jyu.fi
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.forename: Jorma
authors.initials: J
authors.lastname: Tynjälä
authors.forename: Yan
authors.initials: Y
authors.lastname: Lv
authors.forename: Jari
authors.initials: J
authors.lastname: Villberg
authors.forename: Zhouyang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lasse
authors.initials: L
authors.lastname: Kannas
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002648:Child; D002652:Child Behavior; D002681:China; D016001:Confidence Intervals; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D007899:Leisure Activities; D008297:Male; D036301:Qualitative Research; D015203:Reproducibility of Results; D012890:Sleep; D013334:Students; D019966:Substance-Related Disorders / Q000453:epidemiology; D011795:Surveys and Questionnaires / Q000592:standards*