With the original title of Ensayos clínicos en intervenciones no farmacológicas (Non-pharmacological clinical trials) this round table was held in Bellaterra (May 24, 2000). It was chaired by Xavier Bonfil (Unit of Clinical Epidemiology and Public Health, Hospital de la Santa Creu i Sant Pau, Barcelona)and it was finally published as monograph number 30 (Monografías Dr. Antonio Esteve, only published in Spanish).