Clinical Question

What is the best way to diagnose gastroesophageal reflux disease (GERD)?

Evidence Summary

Diagnosis of GERD may be clinical (presentation with typical symptoms, such as heartburn); physiologic (evidence of abnormal pH levels in the distal esophagus); anatomic (evidence of esophagitis on endoscopy); or functional (clinical response to antacid medications). However, the correlation between these diagnostic approaches is relatively poor. For example, many asymptomatic patients have esophagitis, abnormal pH values, or even Barrett esophagus.¹ Furthermore, most studies of GERD diagnosis have taken place in referral populations, so their applicability to the primary care setting is uncertain. Finally, although symptom scores have been developed, they are most helpful in assessing and monitoring the severity of GERD in patients with a known diagnosis,^2–4 they have not been validated,⁵ or they used an inadequate reference standard.^6,7

A recent study developed a new diagnostic score, the GerdQ, which is based on data from primary care patients with upper gastrointestinal (GI) symptoms.⁸ The study used variables from several previous symptom scores, and used focus groups to ensure that the resulting questionnaire was easy for patients to use as a self-reported instrument. The reference standard for GERD was defined as any of the following:

• Esophageal pH of less than 4 for more than 80 minutes per day

• Evidence of esophagitis on endoscopy

• Indeterminate esophageal pH in combination with a positive response to a 14-day course of a proton pump inhibitor

• A highly abnormal symptom score

The final GerdQ tool was evaluated in a group of 308 primary care patients with upper GI symptoms (Table 1).⁸ Increasing scores correlated with increasing severity of heartburn symptoms. The overall accuracy was similar to that of clinical diagnosis by a gastroenterologist.

Another study developed and validated a score to predict the likelihood that patients with upper GI symptoms would respond to the proton pump inhibitor omeprazole (Prilosec).⁹ Using data from 471 patients with GERD-like or ulcer-like dyspepsia, the study identified increasing body mass index (BMI), recent use of antacids or histamine H₂ blockers, nighttime pain, and absence of nausea as independent predictors of response to a two-week course of omeprazole (Figure 1).⁹ A BMI of greater than 29 kg per m² adds points to the score, whereas a BMI of less than 29 kg per m² subtracts points. A simple heuristic is that in patients of average or increased weight, nighttime pain or recent antacid use (in the absence of nausea) predicts a good response to omeprazole.

Physicians may wish to consider having a nurse or medical assistant administer the questionnaires in Table 1⁸ and Figure 1⁹ before an encounter with a patient with dyspepsia or suspected GERD. The questionnaires can also be provided online for patients to take before their visit.