One-week omeprazole treatment in the diagnosis of gastro-oesophageal reflux disease.

BACKGROUND

Symptoms of gastro-oesophageal reflux are common, and currently available methods for diagnosing reflux disease are expensive and uncomfortable for the patient. The diagnostic value of a treatment test with omeprazole is unclear.

METHODS

Patients with dyspepsia including heartburn admitted for upper gastrointestinal endoscopy were studied in a prospective, randomized, double-blind Scandinavian multicentre study. Before entry 188 patients were enrolled, and 160 were randomized to 1-week treatment with 20 mg omeprazole twice daily or placebo. Gastro-oesophageal reflux disease (GERD) was defined as reflux oesophagitis Savary-Miller grades II-III at endoscopy or pH < 4 exceeding 4% of the total time at 24-h oesophageal pH-monitoring and was found in 135 patients. The treatment test was considered positive when the patient's symptoms improved during the treatment week compared with the pretreatment day.

RESULTS

The sensitivity in diagnosing reflux disease was 71-81% with omeprazole as a diagnostic test, compared with 36-47% for placebo during treatment days 3-7. The specificity was similar for the two treatment arms during the first days of the study. During the end of the week a larger proportion of the patients with normal endoscopy and pH test responded to omeprazole treatment, giving omeprazole lower specificity than placebo. The investigators' overall evaluation of whether the patient was a responder to the test had a sensitivity of 75% and a specificity of 55% in the omeprazole-treated patients. The corresponding figures in the placebo group were 17% and 92%, respectively.

CONCLUSION

One week of omeprazole treatment is a simple diagnostic test with a fairly high sensitivity. The specificity is poor owing to the placebo effect and to the lack of a gold standard in diagnosing reflux disease.