Randomized Personalized Trial for Stress Management Compared to Standard of Care

<b>Background/Objectives</b>: Psychological stress is a common problem but hard to universally treat. Personalized (N-of-1) trials assess a participant's response to multiple specific interventions. Though personalized (N-of-1) trials have been used in select interventions, no prior research has examined whether N-of-1 designs provide superior stress reduction relative to standard of care. <b>Methods</b>: Participants were randomized to personalized N-of-1 (N = 106) or standard-of-care (N = 106) arms for three stress-management interventions (mindfulness meditation; yoga; brisk walking). All participants completed ecological momentary assessments (EMA) of stress three times daily for 18 weeks (2-week baseline, 12-week intervention, 2-week assessment, and 2-week follow-up). After the intervention, participants in the N-of-1 arms received a personalized report identifying which intervention worked best for them. All participants chose one intervention to manage their stress during follow-up. The primary outcome was change in perceived stress between baseline and follow-up. <b>Results</b>: Participants in the personalized (N-of-1) arms did not report significantly reduced EMA stress levels relative to standard-of-care (<i>p</i> = 0.496), though the effect was stronger among N-of-1 participants who chose the stress-management intervention recommended by their report [B(SE) = -0.67(0.34); <i>p</i> = 0.049]. <b>Conclusions</b>: Results show the potential of personalized (N-of-1) trials to provide individuals with information unique to them to help identify interventions for stress management. However, many participants in the personalized trial arms did not choose the intervention recommended by their trial. Additional research is required to refine how personalized (N-of-1) trials are conducted and how trial results are reported to participants to ensure the maximal benefit of these trial designs.