Author response

We thank Dr Zermansky for their engagement with our paper. The qualitative part of this mixed-methods study explored influences on antibiotic prescribing and potential reasons for any differences in patterns of prescribing; so, we agree with Dr Zermansky regarding the complexity of antibiotic prescribing decisions and the many different factors affecting decisions.

The purpose of the quantitative analysis was to describe patterns of prescribing for which the retrospective design is appropriate. It does not focus on mechanisms underlying the observed patterns, such as differences in patient-mix. As highlighted in our article, the quantitative analysis focused on patients without relevant comorbidities, and excluded recurrent, chronic, and complicated (for example, bilateral otitis media) presentations, but this does not guarantee that some of the (absence of) differences are explained by other differences in case-mix seen by nurse prescribers, locums, and other GPs.

We did not explore patterns of prescribing across different days of the week, but previous analyses have shown little difference (see Supplementary Tables S1–S2 in Pouwels et al).¹ We accept that our study analysed prescribing data up to 2015 (the dataset that we had access to at the time of the analysis), which we acknowledge as a limitation in the paper.

We disagree with Dr Zermansky’s suggestion that the conclusion should be that all prescribers ‘prescribed antibiotics similarly’. We found a 4% difference between locums’ and other GPs’ antibiotic prescribing. We did not claim this difference to be statistically significant but rather a difference that is potentially clinically significant. To put this 4% in perspective, the 2015/2016 Quality Premium aimed for a reduction in the total number of antibiotics prescribed in primary care by 1% (or greater) from each clinical commissioning group’s 2013/2014 value.²

Overall, we emphasise that our study does not ‘blame’ locums for high prescribing but rather highlights the complex contextual influences on antibiotic prescribing in general practice. Thus, optimising antibiotic prescribing will require changes at the individual, practice, and system levels.

• © British Journal of General Practice 2022