GORDON Brown was left red-faced yesterday after a critical report by his think tank into Scotland’s coronavirus testing regime was completely debunked by the country’s national clinical director.
Professor Jason Leitch said the “fundamental premise” of the report was “actually false”.
The analysis by Our Scottish Future claimed that only about one-third of Scotland’s cases are being picked up by tests.
It came to this conclusion by comparing daily rates for positive tests to an average of Office for National Statistics (ONS) estimates of the total number of people who had the virus.
READ MORE: Gordon Brown’s Our Scottish Future accused of undermining confidence in Covid system
Over a six-week period ending on January 2, the ONS estimated a daily average of around 43,379 people in Scotland had Covid-19, including asymptomatic cases, based on statistical modelling of population samples.
Over the same time period, testing programmes picked up a rolling average of 13,650 cases.
Our Scottish Future claimed this meant 32% of the total cases are being picked up – with the figure for England being 41%, while Wales was at 70% and Northern Ireland at 81%.
However, during yesterday’s coronavirus briefing, Leitch said the methodology used was “unfair.”
According to the spreadsheet accompanying the report, Northern Ireland’s had 16,632 positive tests on January 2, while the estimated prevalence was 10,300. That would give them an impossible detection rate greater than 100%.
Leitch said: “They’ve confused prevalence, which is how much disease you have in your country which is a model number you can’t ever know, with incidence, which is how much you have from your positive tests, how many new cases you find each day.
“They’ve then subtracted one from the other, and come up with a percentage. I don’t think that’s fair. I don’t think it’s statistically correct, either. Our contact tracing has got very high percentages within 24 to 48 hours, and our testing results come back very, very quickly. So I’m very confident the fundamental premise of this document is actually false.”
WATCH: Nicola Sturgeon details exactly why Gordon Brown’s Covid report is wrong
Sturgeon said: “We have significant issues with the methodology, which would mean we would question the conclusions about Scotland’s performance here compared to others.
“More generally, though not every person with Covid in the country features in our confirmed cases because not everybody gets tested.
“There is always an assumption that the true level of infection is higher than the numbers we are reporting here every day and that is all factored into the modelling we do about what we expect to see happen, what the pressure on our health service is going to be.”
The First Minister said there would always be a gap between the number of people tested positive or self-isolating and the true prevalence of the virus.
She said the Government was trying to “narrow that gap” by doing more widespread community mass testing.