Sample size calculation
Heinrich Heine Universität
The required sample size was calculated using G*Power software version 3.1.0 (Institut für Experimentelle Psychologie, Heinrich Heine Universität, Dusseldorf, Germany). It was estimated that a total sample size of 60 patients would have a power of 95.4% to detect a medium to large effect size of 0.87 in the outcome measured.