ABSTRACT
BACKGROUND/AIM: To develop and validate an easy-to-use and cheap method capable of producing placebo from tap water for medicinal water efficacy trials. PATIENTS AND METHODS: Patients were divided into two groups, medicinal water and tap water group. A single 20-minute-long treatment was performed in bathtubs. Patients were asked four times during the bath to tell if they were treated with medicinal water, tap water, or could not decide. Patients were scored, one point was given for each correct answer. RESULTS: A total of 174 patients were enrolled. No significant differences were found either between the average scores or the answers of the two groups. Being familiar with the Harkány medicinal water did not influence the rate of correct answers either. There was no statistically significant difference in the number of changes of opinions between the two groups. CONCLUSION: The used method is appropriate for producing a validated placebo from tap water.
