In this episode we speak to Dr Alex Walker who is an epidemiologist at the Nuffield Department of Primary Care Health Sciences, University of Oxford.Paper: Clinical coding of long COVID in English primary care: a federated analysis of 58 million patient records in situ using OpenSAFELYhttps://doi.org/10.3399/BJGP.2021.0301Early case definitions and clinical guidelines have been published to describe long COVID, and clinical codes based on these guidelines were published in late 2020. This study found wide variation in the early use of these codes, by practice, geographic region, and practice electronic health record software. Promotion of the clinical guidance and codes is important for future research and ongoing patient care.