Placebo effect in surgery for Meniere's disease: three-year follow-up.

In 1981 we published the results of a double-blind, placebo-controlled study in which the efficacy of a regular endolymphatic sac mastoid shunt was compared with a purely placebo operation (mastoidectomy) in controlling the symptoms of 30 patients with typical Meniere's disease. Minor differences could be demonstrated between the shunt and the sham operation, but the greatest difference was between the preoperative and postoperative scores, and both groups improved significantly. It was concluded that the impact of the various endolymphatic sac shunts on the symptoms of patients with Meniere's disease is nonspecific, and that the 70% improvement in both groups was most likely caused by a placebo effect. At the time of the presentation, the results were based on a 1-year follow-up of all patients. As of January 1982 the patients had been followed for a minimum of 3 years. The 3-year results are the same as our results from the first year: no significant difference could be found between the two groups.