'Always take your doctor's advice': Does trust moderate the effect of information on inappropriate antibiotic prescribing expectations?

Objectives To reduce overprescribing, health campaigns urge physicians to provide people with information regarding appropriate antibiotic use and encourage the public to trust their physicians' prescribing decisions. We test (1) whether providing individuals with complete information about the viral aetiology of an illness and the ineffectiveness of antibiotics will reduce inappropriate antibiotic expectations, (2) whether individuals with greater trust in their physician will have lower expectations, and (3) whether individuals with greater trust in their physician will benefit more from the complete information provision and have lower expectations. Design Experiment 1 features a between-subjects design (information provision: baseline vs. complete information) with a general measure of participants' trust in their physician. Experiment 2 features a 2 (physician trustworthiness: low vs. high) × 2 (information provision: baseline vs. complete information) between-subjects design. Methods In Experiment 1, participants (n = 366) reported their trust in their physician, read a vignette describing a hypothetical consultation with a physician for a viral cold and then expressed their expectations for antibiotics. In Experiment 2, participants (n = 380) read a vignette of a consultation with a physician for a viral ear infection then expressed their expectations for antibiotics. Results In both experiments, the provision of complete information significantly reduced inappropriate expectations for antibiotics. Greater trust in physicians was associated with higher antibiotic expectations in Experiment 1, but lower expectations in Experiment 2. In both experiments, trust in physicians appeared to facilitate the effect of information provision, but this effect was weak and inconsistent. Conclusion Providing information about viral aetiology and the ineffectiveness and side effects of antibiotics reduces inappropriate antibiotic expectations. Further research into the effect of trust in physicians as a moderator of the effect information provision is required, particularly given the recent increase in trust-based antibiotic campaigns. Statement of contribution What is already known Inappropriate expectations for antibiotics encourage overprescribing in primary care. To reduce inappropriate expectations, interventions often aim to educate people about antibiotics and encourage them to trust their physician. What does this study add Causal evidence that clinical information provision reduces but does not eliminate inappropriate antibiotic expectations. We find that increased trust in physicians is not always associated with lower expectations for antibiotics. Although increased trust seemed to boost the effect of information provision, this effect was weak and inconsistent.