Reliability and validity of the short form of the child health questionnaire for parents (CHQ-PF28) in large random school based and general population samples.

STUDY
OBJECTIVES: This study assessed the feasibility, reliability, and validity of the 28 item short child health questionnaire parent form (CHQ-PF28) containing the same 13 scales, but only a subset of the items in the widely used 50 item CHQ-PF50.
DESIGN: Questionnaires were sent to a random regional sample of 2040 parents of schoolchildren (4-13 years); in a random subgroup test-retest reliability was assessed (n = 234). Additionally, the study assessed CHQ-PF28 score distributions and internal consistencies in a nationwide general population sample of (parents of) children aged 4-11 (n = 2474) from Statistics Netherlands. MAIN
RESULTS: Response was 70%. In the school and general population samples seven scales showed ceiling effects. Both CHQ summary measures and one multi-item scale showed adequate internal consistency in both samples (Cronbach's alpha>0.70). One summary measure and one scale showed excellent test-retest reliability (intraclass correlation coefficient >0.70); seven scales showed moderate test-retest reliability (intraclass correlation coefficient 0.50-0.70). The CHQ could discriminate between a subgroup with no parent reported chronic conditions (n = 954) and subgroups with asthma (n = 134), frequent headaches (n = 42), and with problems with hearing (n = 38) (Cohen's effect sizes 0.12-0.92; p<0.05 for 39 of 42 comparisons).
CONCLUSIONS: This study showed that the CHQ-PF28 resulted in score distributions, and discriminative validity that are comparable to its longer counterpart, but that the internal consistency of most individual scales was low. In community health applications, the CHQ-PF28 may be an acceptable alternative for the longer CHQ-PF50 if the summary measures suffice and reliable estimates of each separate CHQ scale are not required.