Recently, the government has provided Covid data on a UK basis – merging official figures from the constituent parts of the UK. But are the English and Scottish figures really comparable?
Take figures for the number of Covid patients in hospital in Scotland on 28 August. The Scottish official count is 255, a drop of 42 per cent since 1 July. But this is odd when you see that England has recorded a far higher drop, of 81 per cent (from 2,289 to 430 patients over the same timeframe). The difference is much starker when you analyse the number of patients in hospital beds per population, given England’s population is about ten times greater than Scotland’s.
The answer seems to lie in the definitions. According to the Scottish government, the number of patients in hospital with suspected Covid-19 ‘may include people who are in hospital for other reasons but have previously tested positive for Covid-19’. This is different to the Scottish criteria for new admissions to hospital: only those who ‘tested positive for Covid-19 in the 14 days prior to admission to hospital, on the day of their admission, or during their stay in hospital’ are counted. No equivalent cut-off appears to be made for the count of individuals currently in hospital.
The impact of this difference in definition appears to be substantial: the numbers in hospital in Scotland rose by 15 (to 270) between the 31 July and 4 August. But in those five days, only four Covid admissions were registered. This suggests that other patients admitted to hospital for reasons unrelated to Covid are being counted in the 270.
This is similar to PHE issue with deaths in England, which meant that until the data was rectified, everyone who had ever had Covid at any point was registered as dying from Covid – even if they had been hit by a bus.
The reason for the disparity in the Scottish data is not clear. This fits a pattern of poor quality Covid data, which ends up overestimating the true extent of our problems. Last week, we pointed out similar issues in NHS Wales: Dr Andrew Goodall, its chief executive has responded, saying NHS Wales is
“‘revisiting discussions with our partners, including NHS Wales Informatics Service (NWIS) and Public Health Wales, about separating confirmed and suspected cases.’
This underlines the need for data that we can trust, that is verifiable, and reported in the same way across the devolved nations to allow proper comparison.