Validation of an asthma symptom diary for interventional studies.

OBJECTIVE The Pediatric Asthma Diary was developed and validated to assess efficacy of interventions in children with asthma. DESIGN, PATIENTS, AND SETTING Diary validation was performed in a three week, prospective study of 106 children aged 6-14 years with asthma. Children were classified at baseline as either stable (requiring no additional asthma treatment) or new onset/worse (requiring either addition of or increase in anti-inflammatory treatment). RESULTS A daytime symptom scale and "day without asthma" were defined from diary questions. Both measures demonstrated significant validity and responsiveness to anti-inflammatory treatment. The stable group experienced a higher percentage of days without asthma during week 1 compared with the new onset/worse group (39.6% v 11.6%, respectively). The new onset/worse patients experienced significant improvement in days without asthma (24.5%) compared with stable patients (6.4%). CONCLUSIONS The Pediatric Asthma Diary daytime symptom scale and day without asthma are acceptable measures for use in asthma intervention studies of children aged 6-14 years.