Tracking UK Covid-19 cases  

September 28, 2020

Jason Oke, Daniel Howdon, Carl Heneghan

Updated 14th October:


Last week, Patrick Vallance, the Chief Scientist, said: ‘At the moment we think that the epidemic is doubling roughly every seven days.” 

Vallance said “If, and that’s quite a big if, but if that continues unabated, and this grows, doubling every seven days… if that continued, you would end up with something like 50,000 cases in the middle of October per day.

We put the doubling to the test by creating a tracker of the projection. On the 13 October, the projection was not realised as there was significant divergence in the case data with the 49,000 cases that were projected for this date. We tracked up to date to the 21 October to monitor the changes.

The 7-day moving average takes account of 4 days before and 3 days after to provide an estimate and takes into account the latest reporting – the specimen date takes 5 days to stabilise and therefore lags the current reporting by this amount.


Carl Heneghan is Professor of Evidence-Based Medicine, Director of the Centre for Evidence-Based Medicine and Director of Studies for the Evidence-Based Health Care Programme. (Full bio and disclosure statement here)

Daniel Howdon is a Researcher, Health Economics, LIHS UCU Department Representative, Academic Unit of Health Economics, University of Leeds. Bio here 

Jason Oke is a Senior Statistician at the Nuffield Department of Primary Care Health Sciences and Module Coordinator for Statistical Computing with R and Stata (EBHC Med Stats), and Introduction to Statistics for Health Care Research (EBHC), as part of the Evidence-Based Health Care Programme.

Disclaimerthe article has not been peer-reviewed; it should not replace individual clinical judgement, and the sources cited should be checked. The views expressed in this commentary represent the views of the authors and not necessarily those of the host institution, the NHS, the NIHR, or the Department of Health and Social Care. The views are not a substitute for professional medical advice.