2.3. Randomization
Participants were randomly assigned in a 1:1 ratio to complete either the paper version first or the smartphone version first before answering the questionnaire (CES-D, GAD-7, and K6). The randomization list was generated by a permuted block method (block size 4) using a computer (Microsoft Excel) by a third party unrelated to the study. The randomization list was sent to the Central Registry Center at Kurashiki Heisei Hospital in Okayama Prefecture, Japan, for random assignment.