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The Office for National Statistics (ONS), have released the latest data from their COVID-19 Infection Survey.
Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said:
“The ONS Coronavirus Infection Survey (CIS) has become more important than ever. That’s because the figures for new confirmed cases of Covid-19 on the Government dashboard will become less and less able to indicate trends in infection. They are based on the results of routine tests for the virus, and as the availability of tests reduces because of policy changes, the numbers will change in aways that aren’t necessarily related to the numbers of infections in the population. The CIS tests a representative sample of people across the UK, only to follow the path of the pandemic, so isn’t affected by such biases. Also, the other regular survey of a representative sample of people in England, to follow infection trends, the REACT-1 survey, has stopped, because the Government has decided not to fund it any more.
“This week’s CIS bulletin is a day early because of the holiday weekend, and doesn’t include some of the regular items. It covers the position up to the week 3-9 April.
“There’s some encouraging news, but there are also continuing reasons for some concern. The estimated number of people across the UK who would have tested positive in the week ending 9 April is 4.4 million, down from 4.8 million the week before. ONS estimate that the number of people who would test positive fell in the most recent week in England, Scotland and Northern Ireland, but not in Wales where they say the trend is ‘uncertain’ and the best I can say is that they might have levelled off.
“The estimated falls look reasonably substantial in Northern Ireland and in Scotland, and, allowing for the statistical uncertainty, look as if they have been continuing for a few weeks. But in England, though there was definitely a fall in the most recent week compared to the week before, that’s only a period of one week of falling infections. It could have fallen because the peak has been passed, but a fall lasting only one week doesn’t define a continuing trend. ONS’s Sarah Crofts said “It is too early to say if we have passed the peak of infections”, and I’d certainly agree. I hope the figures for England continue to fall, and that infections in Wales begin to fall too, but a hope is not a prediction. Crofts also pointed out that infections remain high. I’d very much agree with that too. The estimated positivity rate in England is still 1 in 14. That’s slightly lower than last week when it was 1 in 13, but only slightly.
“The short-term trends in the English regions, and in age groups in England, are mixed. In the regions, ONS report a decreasing trend in the most recent week in five of the nine regions (North West, East of England, London, South East and South West), an increasing trend in one (North East), and in the remaining three (Yorkshire and The Humber, East Midlands and West Midlands) the trend in the latest week is uncertain, though there were increases in the most recent two weeks. Positivity rates are now lowest, by a fairly small amount, in what’s been called the ‘greater South East’ – London, the South East and the East of England. In all those regions ONS estimate than 1 in 16 of us would have tested positive in the latest week. The estimated proportions in all the other English regions are 1 in 13 or 1 in 14.
“In the most recent week (ending 9 April), ONS estimate that the proportion who would test positive fell in most of the age groups they use, but not in those of secondary school age (school years 7 to 11) or in those aged 70 and over, where the trends were uncertain. The rates remain pretty high in all the age groups, between 1 in 14 and 1 in 20. The lowest rates are in the groups between school year 7 and age 24, at 1 in 20 or 1 in 19, despite the ‘uncertain’ trend in the school-age group. It’s concerning, though, that the highest estimates rates of testing positive are in the two oldest age groups, 50-69 and 70+, where the estimated rate of testing positive was 1 in 14. Those groups, particularly the 70+ group, are considerably more likely to suffer serious illness if they get infected. Not at the rates that were seen before vaccination, but still high enough to cause some concern.
“So Covid-19 hasn’t gone away, and infections are still common. Yes, there are no legal restrictions in England, and few elsewhere in the UK. We do have to learn to live with the virus – but that doesn’t mean ignoring it. Let’s all please take sensible personal precautions that reduce the chance of getting infected and passing the infection on, as we enjoy the Easter holidays.”
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
Declared interests
Prof Kevin McConway: “I am a Trustee of the SMC and a member of its Advisory Committee. I am also a member of the Public Data Advisory Group, which provides expert advice to the Cabinet Office on aspects of public understanding of data during the pandemic. My quote above is in my capacity as an independent professional statistician.”