OBJECTIVE: The objective was to investigate whether a former randomised study (the Nexium One study) reflects real-life in terms of choice of treatment strategy for longterm treatment of gastroesophageal reflux disease and the associated costs. METHODS: This study is a follow-up study to the Nexium One study and is an open observational study in a general practice setting with 1206 patients. This study was designed as a naturalistic study to emulate a real-life situation as closely as possible. The observational period was six-months. Three groups of patients were included in to this study: 1) patients who participated in the Nexium One trial and were included by general practionernes (GPs), who participated in the Nexium One trial; 2) patients who did not participate in the Nexium One trial and were included by GPs, who participated in the Nexium One trial; and 3) patients who did not participate in the Nexium One trial and were included by GPs, who did not participate in the Nexium One trial. As to whether the randomised Nexium One study reflected real-life in terms of treatment and associated costs, this was investigated by comparing direct medical costs, total costs for the following patients: A) all patients from the Nexium One study and B) group three patients (see above). RESULTS/CONCLUSIONS: A significant difference was found in total costs between group three and all the patients in the Nexium One study. However, there was no significant difference in direct medical costs. In other words, the Nexium One study reflects real-life costs as there is no difference in the costs of treatment between all patients in the Nexium One study and the patients, who did not participate in the Nexium One study and were included by GPs who did not participate in the Nexium One study.