title: Reliability and validity of health status measurement by the TAPQOL.
abstract: BACKGROUND
  In addition to clinical measures in the evaluation of paediatric interventions, health related quality of life (HRQoL) is an important outcome. The TAPQOL (TNO-AZL Preschool children Quality of Life) was developed to measure HRQoL in preschool children. It is a generic instrument consisting of 12 scales that cover the domains physical, social, cognitive, and emotional functioning.
  
  
  OBJECTIVE
  To evaluate the feasibility, score distribution, internal consistency, test-retest reliability, and discriminative and concurrent validity of the TAPQOL multi-item scales in preschool children, aged 2-48 months. Also to evaluate the feasibility, reliability, and validity separately for infants (2-12 months old) and toddlers (12-48 months old).
  
  
  METHODS
  Parents of a random general population sample of 500 preschool children were sent a questionnaire by mail. A random subgroup of 159 parents who participated received a retest after two weeks.
  
  
  RESULTS
  The response rate was 83% at the test and 75% at the retest. There were few missing answers. Six scales showed ceiling effects. Nine scales had Cronbach's alphas >0.70. In general, score distributions and Cronbach's alphas were comparable for infants and toddlers. Test-retest showed no significant differences in mean scale scores; two scales had intra-class correlations <0.50. Five scales showed significant differences between children with no conditions versus children with two or more parent reported chronic conditions.
  
  
  CONCLUSIONS
  Results showed that the TAPQOL is a feasible instrument to measure HRQoL and support the reliability and discriminative validity of the majority of its scales for infants as well as toddlers.
authors.affiliation: Department of Public Health, Erasmus MC, University Medical Center Rotterdam, PO Box 1738, 3000 DR Rotterdam, Netherlands. e.bunge@erasmusmc.nl
authors.forename: E M
authors.initials: EM
authors.lastname: Bunge
authors.forename: M-L
authors.initials: ML
authors.lastname: Essink-Bot
authors.forename: M P H M
authors.initials: MP
authors.lastname: Kobussen
authors.forename: L W A
authors.initials: LW
authors.lastname: van Suijlekom-Smit
authors.forename: H A
authors.initials: HA
authors.lastname: Moll
authors.forename: H
authors.initials: H
authors.lastname: Raat
mesh_terms: D002669:Child Welfare / Q000145:classification*; D002675:Child, Preschool; D002908:Chronic Disease / Q000453:epidemiology; D005240:Feasibility Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007223:Infant; D007229:Infant Welfare / Q000145:classification*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015588:Observer Variation; D011788:Quality of Life; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*