Efficacy of the Otago-Exercise-Programme to reduce falls in community-dwelling adults aged 65-80 when delivered as group or individual training: Non-inferiority-clinical-trial oleh Laura Albornos-Muñoz, Joan Blanco-Blanco, María Ángeles Cidoncha-Moreno, Eva Abad-Corpa, Araceli Rivera-Álvarez, Rosa María López-Pisa, José Manuel Caperos, Otago Project Working Group Consortium, María Teresa Moreno-Casbas