Data at the individual level are needed to direct policies

Concern exists worldwide about the threat posed to human health by antibiotic resistance in common microbial pathogens. In response the World Health Organization has launched a global strategy for containment of antimicrobial resistance and the United Kingdom has an antimicrobial resistance strategy and action plan.1 2 Fundamental to any action is an accurate understanding of the relation between prescribing and resistance. This is especially important where most prescribing occurs—in the community.

At the level of individual patients a link between prescribing and resistance has been found for many bacteria.3 In the United Kingdom, data about antibiotic prescribing are usually available only at the practice level. These have been investigated in relation to bacterial resistance to antibiotics, with only a weak association found.4 The validity of such analysis can be questioned, however, because exposure and outcome in any one individual are not linked and controls are not available. These potential flaws can be overcome by use of individual patient …