title: Disentangling the effects of current age, onset age, and disease duration: parent and child attitudes toward diabetes as an exemplar.
abstract: OBJECTIVE
  To develop a methodology for use with cross-sectional data to disentangle the effects of current age, disease onset age, and disease duration in chronically ill children.
  
  
  METHODS
  We used a questionnaire data set from a large cross-sectional sample of mothers and children with Type 1 diabetes. The interdependence of current age, onset age, and disease duration precluded use of all three in the same regression model. Consequently, pairs of models were run, looking for a pattern in the results.
  
  
  RESULTS
  The approach successfully disentangled the differential effects of the child's current age, disease onset age, and disease duration. Child current age predicted child attitudes about diabetes management rules, child sick-role identification, and maternal attitudes toward medical staff. Onset age predicted child-perceived family disruption and mothers' confidence in detecting a hypoglycemic reaction. Disease duration predicted maternal religious beliefs about diabetes and maternal attitudes toward medical staff.
  
  
  CONCLUSIONS
  This study illustrates a methodology for disentangling the effects of child current age, disease onset age, and disease duration in cross-sectional data that may be useful for any childhood chronically ill population that varies in child onset age.
authors.affiliation: University of Florida Health Science Center, Gainsville, FL 32610-0165, USA. sjohnson@hp.ufl.edu
authors.forename: Suzanne Bennett
authors.initials: SB
authors.lastname: Johnson
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Meltzer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001294:Attitude to Health; D002648:Child; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000379:methods*; D012044:Regression Analysis; D013223:Statistics as Topic / Q000379:methods*; D013997:Time Factors