RCT to compare the cost-effectiveness of two alternative case-finding approaches for identifying undiagnosed COPD

There is significant under-diagnosis of COPD in the UK and elsewhere and many GP groups have actively started to seek undiagnosed cases. However, the most effective and cost-effective approach is not known as published studies are small and/or without comparison groups.

We plan to recruit 28 practices and randomly assign patients aged 40-79 years who are current or ex-smokers, to either an “active case-finding arm” or an “opportunistic only” arm. We will also compare with a further 28 practices undertaking “routine care”. Patients in the “opportunistic only” arm will receive a questionnaire about simple respiratory symptoms when they attend surgery routinely. Patients in the “active” arm will not only be flagged for these questions in surgery, but will also be actively sent a questionnaire by post.

Any patients who report any of the relevant respiratory symptoms will be invited for spirometry, and we estimate that approximately 16% of these will subsequently be diagnosed with COPD. We will compare which method is the most effective and cost-effective in identifying new patients, and also undertake sensitivity analysis and modelling to project future benefits of different approaches. We also plan a series of qualitative interviews to explore patients’ views.