Enter the six standardized pH monitoring metrics to visualize the composite DeMeester acid exposure profile.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Objective quantification of esophageal acid exposure (GERD)
Evaluation of "refractory" GERD symptoms despite high-dose PPI therapy (performed off-PPI)
Pre-operative evaluation before anti-reflux surgery (Fundoplication, LINX)
Workup for extra-esophageal symptoms (chronic cough, asthma) suspected to be reflux-related
Exclusion Criteria
The DeMeester score was developed for catheter-based (24-hour) pH monitoring. While widely applied to wireless (Bravo) 48–96 hour studies, the thresholds may vary, and the score should be calculated for each day individually to assess consistency.
Section 2
Formula & Logic
The 6 Weighted Parameters
01
Total % time pH < 4.
02
Upright % time pH < 4.
03
Supine % time pH < 4.
04
Number of reflux episodes.
05
Number of long episodes (> 5 minutes).
06
Duration of longest reflux episode.
Scoring Logic
The individual parameters are normalized against healthy control data (standard deviation units) and summed to provide a single composite score.
Interpretation Threshold
Score < 14.72
Normal Acid Exposure
Score ≥ 14.72
Abnormal Acid Exposure (Pathological GERD)
Section 3
Pearls/Pitfalls
Why This Remains the Legal Standard
The DeMeester score is the oldest and most validated composite score for GERD. Despite the emergence of the Lyon Consensus (which focuses on Acid Exposure Time/AET), the DeMeester score remains a requirement in most insurance policies and surgical guidelines to prove "pathological acid reflux" before invasive intervention.
The "Broken" DeMeester
A high score driven *only* by the number of episodes (but with a normal total % time) may reflect aerophagia (excessive swallowing) rather than true pathological reflux.
Clinical Pearls
Total Acid Exposure Time (AET) > 6% is the modern "Lyon Consensus" equivalent of a positive DeMeester score
Symptoms should be correlated using the Symptom Index (SI) or Symptom Association Probability (SAP) alongside the score
A normal DeMeester score in a symptomatic patient suggests Functional Heartburn or Hypersensitive Esophagus
Section 4
Next Steps
Interpreting the Result
01
Score ≥ 14.7: High confidence for Pathological GERD. Excellent candidate for anti-reflux surgery.
Developed by Tom DeMeester and Lawrence Johnson in the early 1970s at the University of Southern California. It was the first "objective" tool to move GERD diagnosis from subjective patient reporting to physiological measurement, fundamentally changing the selection criteria for fundoplication.
