title: Psychometric properties of the Child Health Assessment Questionnaire (CHAQ) applied to children and adolescents with cerebral palsy.
abstract: BACKGROUND
  Cerebral palsy (CP) patients have motor limitations that can affect functionality and abilities for activities of daily living (ADL). Health related quality of life and health status instruments validated to be applied to these patients do not directly approach the concepts of functionality or ADL. The Child Health Assessment Questionnaire (CHAQ) seems to be a good instrument to approach this dimension, but it was never used for CP patients. The purpose of the study was to verify the psychometric properties of CHAQ applied to children and adolescents with CP.
  
  
  METHODS
  Parents or guardians of children and adolescents with CP, aged 5 to 18 years, answered the CHAQ. A healthy group of 314 children and adolescents was recruited during the validation of the CHAQ Brazilian-version. Data quality, reliability and validity were studied. The motor function was evaluated by the Gross Motor Function Measure (GMFM).
  
  
  RESULTS
  Ninety-six parents/guardians answered the questionnaire. The age of the patients ranged from 5 to 17.9 years (average: 9.3). The rate of missing data was low (<9.3%). The floor effect was observed in two domains, being higher only in the visual analogue scales (< or = 35.5%). The ceiling effect was significant in all domains and particularly high in patients with quadriplegia (81.8 to 90.9%) and extrapyramidal (45.4 to 91.0%). The Cronbach alpha coefficient ranged from 0.85 to 0.95. The validity was appropriate: for the discriminant validity the correlation of the disability index with the visual analogue scales was not significant; for the convergent validity CHAQ disability index had a strong correlation with the GMFM (0.77); for the divergent validity there was no correlation between GMFM and the pain and overall evaluation scales; for the criterion validity GMFM as well as CHAQ detected differences in the scores among the clinical type of CP (p < 0.01); for the construct validity, the patients' disability index score (mean:2.16; SD:0.72) was higher than the healthy group (mean:0.12; SD:0.23)(p < 0.01).
  
  
  CONCLUSIONS
  CHAQ reliability and validity were adequate to this population. However, further studies are necessary to verify the influence of the ceiling effect on the responsiveness of the instrument.
authors.affiliation: Associação de Assistência à Criança Deficiente (AACD), Rua da Doméstica, 250, Uberlândia, Minas Gerais 38413-168, Brazil. niveamacedo@netsite.com.br
authors.forename: Nívea M O
authors.initials: NM
authors.lastname: Morales
authors.forename: Carolina A R
authors.initials: CA
authors.lastname: Funayama
authors.forename: Viviane O
authors.initials: VO
authors.lastname: Rangel
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Frontarolli
authors.forename: Renata R H
authors.initials: RR
authors.lastname: Araújo
authors.forename: Rogério M C
authors.initials: RM
authors.lastname: Pinto
authors.forename: Carlos H A
authors.initials: CH
authors.lastname: Rezende
authors.forename: Carlos H M
authors.initials: CH
authors.lastname: Silva
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D001938:Brazil; D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult