The Infant Gastroesophageal Reflux Questionnaire Revised: Development and Validation as an Evaluative Instrument

Background & Aims: Gastroesophageal reflux disease (GERD) is frequently experienced by infants, and disease-specific measures are needed to evaluate treatment benefits. We revised the Infant Gastroesophageal Reflux Questionnaire (I-GERQ) on the basis of information from parents of infants with GERD and physicians and subjected it to a psychometric evaluation. Methods: A 3-week, multi-country observational study of 185 caregivers of infants younger than 18 months with GERD and 93 caregivers of control infants was conducted. Caregivers completed the I-GERQ-R weekly and recorded symptoms in a Daily Diary. Caregivers and physicians rated global disease severity and change in overall GERD symptoms. Results: Slightly more than half of infants were male with a mean age of 6.7 months, and most infants had been diagnosed with GERD for a little more than 2 months (mean, 66.7 days). Internal consistency reliability for the I-GERQ-R ranged from 0.86 to 0.87, and test-retest reliability was 0.85. Construct validity was demonstrated by significant differences between cases and controls on all item scores (all P < .01) and the total score (P < .0001), correlations with relevant Daily Diary symptoms, and both physician-rated (P < .05) and caregiver-rated disease severity (P < .05). Mean baseline to 3-week I-GERQ-R change scores for those infants whose caregivers reported improvement was −5.7 compared with −0.3 for those whose caregivers reported worse/same (P < .001). Physician ratings of change resulted in similar findings, with mean changes of −5.7 for those rated improved and −0.1 for those rated as worse/same (P < .0001). Conclusion: This study demonstrated the I-GERQ-R is a reliable, valid, and clinically responsive measure of infant GERD symptoms.