Clinically Meaningful Difference for the Infant Gastroesophageal Questionnaire Revised version (I-GERQ-R): A Quantitative Synthesis.

BACKGROUND: Gastroesophageal reflux disease (GORD) is a common condition affecting 30% of infants aged 0-23 months. The Infant Gastroesophageal Questionnaire Revised version (I-GERQ-R) is an observer-reported outcome measures (ObsRO) developed to evaluate the impact of GORD on young infants. However, evidence regarding the clinically important difference (CID) for the I-GERQ-R is limited. The aim of this study was to determine a CID for the I-GERQ-R. METHODS: A literature review was undertaken (PsycInfo, Embase, MedLine and EconLit databases) for longitudinal studies involving the I-GERQ-R. Articles were not limited by language or publication date. A random effects model was applied to calculate an overall CID, along with I2 and Q statistics. Publication bias was also assessed. RESULTS: The search identified 42 articles; 11 were selected for full-text review and 7 articles were identified for full data extraction. The studies included a total of 661 infants (range: 30 to 313); 424 infants had been diagnosed with GORD (64%). The age range of the infants across the studies was from birth to 7 months. The overall CID was -6.54 (95% confidence interval: -4.35 to -8.74), Q = 17.96, p=0.08 and I2=22.04. CONCLUSION: This study derived a CID for the I-GERQ-R and indicated a threshold around 6 could signify a clinically important difference for this instrument. The lower limit of the 95% confidence interval suggested a threshold of 3 to 4 could represent a minimally important difference. These results may help inform clinical decisions in evaluating meaningful change in symptom severity in children affected by GORD.