At the height of the COVID pandemic everybody, from health ministers to Joe public, wanted to know two things: how many infected people are there in the country? And is this number going up or down?
There were many sources for these figures, from the Office for National Statistics to the Zoe app. We wanted to know which of these methods was the most reliable during the first two years of the pandemic. Our results have just been published in The Lancet Public Health.
In judging the effectiveness of the various surveillance methods, we looked at three criteria. First, to what degree did the method reflect whether cases were rising or falling? Second, how accurate was it in giving estimates of the actual infection numbers? And, third, was the data available swiftly enough for control measures, such as enhanced contact tracing, to be rapidly put in place?
