Background: Diagnosis of GERD is based on presence of symptoms (heartburn) associated to abnormal esophageal acid exposure or esophageal erosions determined by 24-hr pH monitoring and/or endoscopy, respectively. Different instruments have been evaluated in order to diagnose GERD without invasive studies. Carlsson-Dent questionnaire (CDQ), validated among European patients, have shown good sensitivity and positive predictive values for detection of GERD. Diagnostic usefulness of the CDQ in Mexican patients is unknown.
Objective: To evaluate usefulness of CDQ among patients with erosive GERD (EG) and non-erosive GERD (NERD).
Patients and methods: Consecutive patients with heartburn at least twice per week during the last three months and previous endoscopy were included. All patients answered a self-administered Spanish version of the CDQ, previously evaluated for its content validity and easy application. A score of > or = 4 was considered as positive for GERD. All patients underwent 24-hr pH esophageal monitoring to determine the presence of pathologic reflux (% time pH < 4, > 4.2), as well as the symptom index (SI). Questionnaire's sensitivity (S), specificity (E), positive and negative predictive values (PPV, NPV) were calculated using 24-hr pH monitoring and endoscopic oesophagitis as gold-standard tests.
Results: A total of 125 patients were evaluated, 81 women (65%) and 44 men (35%) with an age of 47.9 (21-83). Eighty-six patients (69%) had NERD and 39 (31%) EG. Among patients with NERD, 28 (32%) had abnormal pH study, 10 (12%) had normal pH study with positive SI (> 50%), and 48 (65%) had normal pH study with negative SI. Most common symptom was a burning feeling rising from the stomach or lower chest up towards the neck (classic definition of heartburn) in 53%, noncardiac chest pain in 14%, and nausea in 5%. In 44 patients (35%) the main discomfort occurred within 2 hours of taking food, and in 77% it worsed with larger meals and food rich in fat, as well as in 77% after taking spicy food. One hundred and seven patients (86%) scored > or = 4 on CDQ and there was no significantly difference between CDQ score among groups. CDQ's sensitivity compared to pH monitoring was 89%, and PPV 55%. When compared to endoscopic findings, sensitivity was 94% and PPV 90. There was strong and significative correlation between esophageal acid exposure and higher CDQ's scores.
Conclusions: CDQ in Spanish is an useful instrument for detection of GERD, and its score correlates with the degree of esophageal acid exposure.