The infant gastroesophageal reflux questionnaire revised: development and validation as an evaluative instrument

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.

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.

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).

This study demonstrated the I-GERQ-R is a reliable, valid, and clinically responsive measure of infant GERD symptoms.