Author response

Many thanks for reading our paper ‘Associations between general practice characteristics and chest X-ray rate’ and for your comments.

In the paper we discuss some of the evidence around numbers of chest X-rays requested by GPs and lung cancer outcomes. We noted that, although we feel that it is plausible that increasing the number of chest X-rays requested for patients who have symptoms who are at risk of lung cancer could improve outcomes, the evidence base regarding this remains equivocal. We agree that the research presented in our paper would not warrant a definitive assertion that increasing numbers of chest X-rays performed in general practice improves outcomes. While we feel such an association is plausible, and discussed evidence that suggests that increasing frequency of chest X-ray investigations in patients who have symptoms may contribute to earlier-stage diagnosis,¹ we did not assert that such an association exists.

The study examined the numbers of chest X-rays performed in relation to characteristics of practices and their populations. The study did not include data on cancer outcomes, therefore we would not have been able to prove any effect on outcomes caused by differences in chest X-ray rates, and this was not an objective of the study. However, we agree this is an important research question and we are planning to undertake a study that does examine chest X-ray rates of general practices in relation to lung cancer outcomes.

We agree that screening of asymptomatic patients using low-dose CT will have an increasingly important role in lung cancer detection over the coming years. However, because less than half of all patients with lung cancer fulfil eligibility criteria for screening,² and even among those eligible only about half will attend,³ screening will only ever detect a small proportion of lung cancers overall. Thus, even if CT screening for lung cancer is rolled out in the UK and elsewhere, the role of GPs in detecting symptomatic disease will remain crucial.

• © British Journal of General Practice 2022