Statistical Analyses
The sample size was predetermined based on the methodology presented in the Professional Society for Health Economics and Outcomes Research ePRO Good Research Practices Task Force report [The equivalence margin was defined as ±7.0 points from the MCID of the J-OSDI total score [We assessed the internal consistency of the app-based J-OSDI using the Cronbach α coefficient [To compare the characteristics of the participants between the app-paper and paper-app groups, we conducted an unpaired 2-tailed 