404: Personal data not found — Anonymous vs. account-based internet self-help for social anxiety in a partially randomized patient preference trial

Abstract

Background Privacy and data security concerns are frequently cited barriers to the adoption of internet-based interventions. Allowing anonymous use may reduce these barriers, but whether anonymity affects clinical outcomes is unclear. Objective This study compared an internet-based self-help intervention for social anxiety offering platform-level anonymity with a conventional account-based version and investigated whether anonymity preferences were associated with outcomes. Methods In this partially randomized patient preference trial, 452 adults with heightened social anxiety symptoms were assigned by randomization or preference to an anonymous or account-based 8-week unguided cognitive behavioral self-help program. Assessments occurred at baseline, post-treatment, and 24-week follow-up. The primary outcome was social anxiety severity, analyzed with mixed-effects models testing superiority of the account-based version. Results Participants showed substantial reductions in social anxiety symptoms (within-group d = −0.81 to −0.62). The account-based version was not superior in either arm. The post-treatment between-version difference was small (d = 0.09, 95% CI: −0.17 to 0.35) and robust across sensitivity analyses. Secondary outcomes including depressive symptoms and mental quality of life also improved. Improvements were maintained at follow-up. Most participants preferred the account-based version. Exploratory analyses provided no robust evidence of outcome differences by preference or preference match. Discussion The platform-level anonymous intervention was not outperformed by the conventional account-based program. Because the trial was powered for superiority and included no non-active control, formal equivalence and absolute efficacy remain to be established. Within these limits, the findings provide no evidence that the privacy-protective, account-free design came at the cost of reduced symptom improvement.