Construct validity and responsiveness of the Child Health Questionnaire in children with acute asthma.

OBJECTIVE

To examine the validity and responsiveness of the Child Health Questionnaire (CHQ-PF28) in the context of acute exacerbation of asthma in children.

DESIGN AND METHODS

This was a prospective cohort study of children age 5 years and older treated for acute asthma at two urban pediatric emergency departments (EDs). At 14 days after the visit, all patients were contacted by telephone and the CHQ-PF28 (modified to have a 2-week recall period) was administered. Poor 14-day outcome was defined as one or more of the following: child or parent missed at least 5 days of school/day care/work; child still having asthma symptoms above baseline at 14 days; or unscheduled care within 7 days after the ED visit.

RESULTS

A total of 732 subjects (median age, 9 years) were enrolled; 622 (85%) had successful follow-up at day 14. At the 14-day follow-up, 254 (43%) were classified as having a poor outcome. The mean physical subscale score of the CHQ-PF28 was 48.2 among those with a good outcome, vs 35.9 among the poor outcome group (difference = 12.3; 95% confidence interval, 10.2 to 14.3). For the psychosocial subscale the average difference between groups was 6.9 (95% confidence interval, 5.1 to 8.7). Among the 146 patients at one site who also had a CHQ score obtained at the initial visit, there was a significant improvement in mean physical subscale score among those with good, but not poor, outcome. However, the relative responsiveness was moderate, with an effect size of only 0.37.

CONCLUSIONS

Both the physical and psychosocial subscales of the CHQ-PF28 administered 14 days after an ED visit for acute exacerbation of asthma are correlated with poor short-term functional outcome, but scores are only moderately responsive to acute changes in functional status.