Physicians face intense work-related stress, which can harm their health, increase the risk of medical errors, lower healthcare quality, and increase costs within the healthcare system. In this 4-week intervention study, individual-level and population-level effects of two short and easy-to-perform breathing exercises designed to reduce stress are evaluated among 76 physicians in residency in Germany in a series of N-of-1 trials. Levels of stress and levels of stress expected for the following day were assessed electronically every day via the StudyU App. Intervention effects were estimated using Bayesian linear regression models and were overall small on the population level but they showed large heterogeneity between individuals with strong effects for selected individuals. Twenty-seven participants benefitted from the anti-stress exercises. Three (Mindfulness Breathing) and seven participants (box breathing) had a ≥70% probability for a daily stress reduction of ≥0.5 points and thereby fulfilled our responder criteria. On average, 4.5 months after completion of the individual N-of-1 trials, a follow-up survey among all participants was conducted to assess sustainability of the interventions. Although general implementation of these anti-stress exercises cannot be recommended, they can be highly effective for selected individuals and potentially beneficial in specific subgroups.

VMV: none. TK: reports outside of the submitted, to have received research grants from the German Federal Joint Committee (G-BA). He also received personal compensation from Eli Lilly & Company, Novartis, the BMJ, and Frontiers. SK: none.

NCT06368791

This study did not receive any funding.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Ethics Committee of the Charité - Universitätsmedizin Berlin gave ethical approval for this work (approval number EA4/260/23).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes