Statistical analysis
The statistical analysis, including the sample size calculation, was done in cooperation with the Institute for Medical Biometry and Computer Science of the University of Heidelberg. Statistical analyses and descriptive statistics were performed with SPSS version 25.0 (IBM SPSS Inc., Chicago, Illinois, USA). Data were given as absolute frequency and as mean ± standard deviation. The evaluation was carried out under consideration of the crossover design [Differences between the TS and VR groups were assessed for parametric data using the 