The effectiveness of repeating a social norm feedback intervention to high prescribers of antibiotics in general practice: a national regression discontinuity design

Objectives Unnecessary antibiotic prescribing contributes to antimicrobial resistance. A randomized controlled trial in 2014–15 showed that a letter from England’s Chief Medical Officer (CMO) to high-prescribing GPs, giving feedback about their prescribing relative to the norm, decreased antibiotic prescribing. The CMO sent further feedback letters in succeeding years. We evaluated the effectiveness of the repeated feedback intervention. Methods...