What is the cut-off score, sensitivity, and specificity of the Infant Gastroesophageal Reflux Disease (GERD) questionnaire?

Infant GERD Questionnaire: Cut-off Score and Diagnostic Performance

The Infant Gastroesophageal Reflux Questionnaire Revised (I-GERQ-R) uses a cut-off score of ≥16 to suggest GERD, but this threshold has poor diagnostic accuracy and should not be relied upon for clinical decision-making, particularly in infants under 4 months of age.

Understanding the I-GERQ-R Scoring System

The I-GERQ-R is a validated symptom questionnaire recommended by the American Academy of Pediatrics for documenting and monitoring parent-reported GERD symptoms in infants 1. The questionnaire generates a total score based on symptom frequency and severity 2.

Traditional Cut-off Score

• Cut-off of ≥16 has been historically suggested to differentiate between physiologic gastroesophageal reflux (GER) and pathologic GERD 3, 4
• This threshold was established in the original validation studies 2

Critical Limitations of the Cut-off Score

Age-Dependent Normal Values Invalidate the Fixed Cut-off

The fixed cut-off of ≥16 is inappropriate for young infants because normal, healthy infants frequently score above this threshold:

• 16% of healthy infants aged 0-1 months score ≥16 3
• 4% of healthy infants aged 3-4 months score ≥16 3
• Scores ≥16 disappear after 16 months of age in healthy infants 3
• High scores in young infants are driven by normal developmental phenomena: regurgitation, colic-associated symptoms, and hiccup frequency 3

Poor Diagnostic Performance

The I-GERQ-R demonstrates unacceptably poor sensitivity and specificity when validated against objective measures:

• Sensitivity: 43% and Specificity: 79% when validated against 24-hour pH monitoring in one study 5
• The questionnaire failed to identify 26% (8 of 31) of infants with documented GERD 4
• Conversely, it was falsely positive in 81% (17 of 22) of infants with normal biopsy and pH studies 4
• Clinical symptoms show poor correlation with both pH-metry and histologic esophagitis 4

Clinical Implications and Recommendations

When to Use the I-GERQ-R

The questionnaire is best used for monitoring symptom changes over time rather than diagnosis:

• Demonstrated excellent reliability (internal consistency 0.86-0.87, test-retest 0.85) 2
• Shows responsiveness to clinical change: mean score decreased by 5.7 points in improved infants versus 0.3 in unchanged infants 2
• Useful for documenting symptom patterns and tracking treatment response 1

Diagnostic Approach When GERD is Suspected

The American Academy of Pediatrics emphasizes that history and physical examination are sufficient for diagnosis in most cases, not questionnaires 1, 6:

• Warning signs requiring investigation include: bilious vomiting, GI bleeding, consistently forceful vomiting, fever, lethargy, hepatosplenomegaly, bulging fontanelle, seizures, abdominal distension, or genetic syndromes 1
• Objective testing (upper GI series, pH monitoring, endoscopy with biopsy, impedance monitoring) should be reserved for cases with warning signs or diagnostic uncertainty 1, 7
• Empiric PPI trial is recommended as first-line diagnostic and therapeutic approach for typical symptoms without alarm features 6

Common Pitfalls to Avoid

• Do not diagnose GERD based solely on I-GERQ-R score ≥16, especially in infants under 4 months 3, 4
• Do not order routine imaging based on questionnaire results alone; imaging is not justified for GERD diagnosis in otherwise healthy infants 1
• Recognize that regurgitation and crying are common in healthy infants (45% and 20% respectively) and do not necessarily indicate pathologic reflux 4
• Understand the discordance between symptoms, pH studies, and histology: 38% of infants with pathologic pH studies have normal biopsies, and 53% with esophagitis have normal pH studies 4