Cornelia Betsch

The overprescription of antibiotics due to diagnostic uncertainty and inappropriate patient expectations influence antimicrobial resistance. This research assesses (i) whether communicating diagnostic uncertainty reduces expectations of receiving antibiotics and (ii) which communication strategies minimise unintended consequences of such communication. In two experimental online studies conducted in January and April 2023, participants read a vignette describing a doctor consultation for an ear infection and expressed their expectations of receiving antibiotics, trust in their doctor, rated the doctor's reputation and provided their intention to get a second doctor's opinion. Study 1 ( N = 2213) investigated whether communicating diagnostic uncertainty and social externalities of antibiotic use (the negative social impacts of developing antibiotic resistance) decreases expectations for antibiotics and explores potential unintended consequences on the doctor–patient relationship. In Study 2 ( N = 527), we aimed to replicate and extend the findings by adding specific treatment recommendations. Disclosing diagnostic uncertainty (vs. certainty) and communicating (vs. not communicating) the social externalities of antibiotic overuse reduced patients' expectations of receiving antibiotics. Yet, communicating uncertainty impaired trust in the doctor and the doctor's reputation. Combining the communication of uncertainty with specific treatment recommendations—particularly delayed antibiotic prescriptions—showed important to prevent these unintended consequences.