Previous observational studies have indicated that social influences, such as arising from herding-like behaviour, can contribute to medical errors. In this study, we experimentally examined whether 475 primary care physicians practicing in England would follow incorrect prescription recommendations from fellow physicians and specialists. To investigate this, we conducted a web-based survey that included two case vignettes: Case vignette 1 focused on sleeping tablets, and case vignette 2 centered around antibiotics. The vignettes were presented in random order, and within each vignette, study participants were assigned to one of three experimental conditions: control condition (lacking peer recommendation), fellow physician condition (including a recommendation from a fellow primary care physician not aligned with best practice clinical guidelines), or specialist condition (including a recommendation from a specialist not aligned with best practice clinical guidelines). The primary outcome measure was the proportion of primary care physicians who prescribed medication that deviated from best practice clinical guidelines. We found that, in both case vignettes, the percentage of respondents prescribing such medication was highest in those assigned to the specialist condition, followed by those assigned to the control condition. It was lowest in those assigned to the fellow physician condition (case vignette 1: 73.8% vs. 55.6% vs. 36.6% and case vignette 2: 24.0% vs. 12.4% vs. 10.1%). There was no statistically significant difference between the latter two conditions. This suggests that primary care physicians are more likely to prescribe medication that deviates from best practice clinical guidelines when they receive corresponding recommendations from specialists. This is the first experimental study providing evidence that herding-like behaviour among physicians can indeed lead to prescription errors. As our study only investigated hypothetical scenarios, subsequent studies should explore herding-like behaviour in real-world practice.
