Martin J Llewelyn , professor of infectious diseases 1 2 , Jennifer M Fitzpatrick , specialist registrar in infection 2 , Elizabeth Darwin , project manager 3 , SarahTonkin-Crine , health psychologist 4 , Cliff Gorton , retired building surveyor 5 , John Paul , consultant in microbiology 6 , Tim E A Peto , professor of infectious diseases 7 , Lucy Yardley , professor of health psychology 8 , Susan Hopkins , consultant in infectious diseases and microbiology 9 , Ann Sarah Walker , professor of medical statistics and epidemiology 3 1Department of Global Health and Infection, Brighton and Sussex Medical School, Falmer, BN1 9PS, UK 2Department of Microbiology and Infection, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK 3Nuffield Department of Medicine, University of Oxford, UK 4Nuffield Department of Primary Care Health Sciences, Oxford, UK 5Oxford, UK 6Public Health England, Royal Sussex County Hospital, Brighton, UK 7Oxford Biomedical Research Centre, Oxford, UK 8Faculty of Human and Social Sciences, University of Southampton, UK 9Royal Free London NHS Foundation Trust, London, UK Correspondence to: M Llewelyn M.J.Llewelyn@bsms.ac.uk

With little evidence that failing to complete a prescribed antibiotic course contributes to antibiotic resistance, it’s time for policy makers, educators, and doctors to drop this message, argue Martin Llewelyn and colleagues

Antibiotics are vital to modern medicine and antibiotic resistance is a global, urgent threat to human health. The relation between antibiotic exposure and antibiotic resistance is unambiguous both at the population level1 and in individual patients.2 Reducing unnecessary antibiotic use is therefore essential to mitigate antibiotic resistance.

Avoiding overuse requires healthcare professionals and the public to be well informed about antibiotic treatment, as set out in the first objective of the World Health Organization Global Action Plan.3 Public communication about antibiotics often emphasises that patients who fail to complete prescribed antibiotic courses put themselves and others at risk of antibiotic resistance. For example, in materials supporting Antibiotic Awareness Week 2016 WHO advised patients to “always complete the full prescription, even if you feel better, because stopping treatment early promotes the growth of drug-resistant bacteria.”4 Similar advice appears in national campaigns in Australia,5 Canada,6 the United States,7and Europe.8 And in the United Kingdom it is included as fact in the curriculum for secondary school children.9

However, the idea that stopping antibiotic treatment early encourages antibiotic resistance is not supported by evidence, while taking antibiotics for longer than necessary increases the risk of resistance. Without explicitly contradicting previous advice, current public information materials from the US Centers for Disease Control and Prevention (CDC) and Public Health England have replaced “complete the course” with messages advocating taking antibiotics “exactly as prescribed.”1011 We explore the evidence for antibiotic duration, clinical effectiveness, and resistance, and encourage policy makers, educators, and doctors to stop advocating “complete the course” when communicating with the …