Figures on coronavirus testing released daily by the government are “far from complete and comprehensible”, the UK’s statistics watchdog has claimed.
In a scathing letter to health secretary Matt Hancock, UK Statistics Authority chair Sir David Norgrove said the way data on testing is currently analysed and presented to the public gives “limited value”.
He said testing statistics “fall well short of expectations”, claiming “it is not surprising that given their inadequacy data on testing are so widely criticised and often mistrusted”.
“Statistics on testing perhaps serve two main purposes,” the letter states.
“The first is to help us understand the epidemic… showing us how many people are infected, or not, and their relevant characteristics.
“The second purpose is to help manage the test programme, to ensure there are enough tests, that they are carried out or sent where they are needed and that they are being used as effectively as possible. The data should tell the public how effectively the testing programme is being managed.
“The way the data are analysed and presented currently gives them limited value for the first purpose. The aim seems to be to show the largest possible number of tests, even at the expense of understanding. It is also hard to believe the statistics work to support the testing programme itself. The statistics and analysis serve neither purpose well.”
Hancock told yesterday’s coronavirus briefing figures for the government’s new track and trace testing system are not yet available, but that it was "up and running" and had been successful so far.
The figures relating to the number of people tested – which stood at 128,437 on Monday – includes those posted as well as carried out.
Sir David’s letter goes on: “The headline total of tests adds together tests carried out with tests posted out. This distinction is too often elided during the presentation at the daily press conference, where the relevant figure may misleadingly be described simply as the number of tests carried out. There are no data on how many of the tests posted out are in fact then successfully completed."
The authority said the way the figures are presented in general is “difficult to understand” and urged the government to make changes to ensure they are comprehensible to the public.
Norgrove welcomes the DHSC’s willingness to work with the Office for Statistics Regulation to discuss how the data and their presentation could be improved and gaps addressed. OSR will be happy to help further in any way they can.
“It would be useful to develop a published timetable for the changes that need to be made and for the development of the metrics for the vital new programme of Test and Trace,” he said.
“I do understand the pressures that those concerned have faced and still face. But I am sure you would agree that good evidence, trusted by the public, is essential to success in containing the virus.”