Figure. Study Flowchart.

Five participants in the usual care group withdrew from the study; of those, 3 participants did not report any reason, 1 did not benefit from the study, and 1 had pain elsewhere. Eighteen participants in the app group withdrew from the study; of those, 5 participants did not report any reason, 3 had technical problems, 3 found the app not relevant, 2 thought that joining the study was a prerequisite to get treatment at the clinic, 2 had other health issues, 2 had pain elsewhere, and 1 had personal reasons. Eleven participants in the e-Help group withdrew from the study; of those, 6 did not report any reason, 2 changed clinic, 1 had pain elsewhere, 1 thought it was too much effort, and 1 had a change in clinical situation and found no meaning in participating any longer. The main per-protocol analysis was based on accessing the intervention at least once for both the app and e-Help intervention groups. ITT indicates intention to treat.