SIX in ten Covid patients in December and January were admitted to hospital 'because of' their infection, according to the first audit data for Scotland.

The report by Public Health Scotland, which is based on an analysis of patient records at Greater Glasgow and Clyde and Grampian health boards at the end of December and beginning of January, indicated that 60 per cent were in hospital as a result of illness caused by their infections. 

The figures were "reasonably similar" between the two boards, said PHS. 

It is the first analysis since the Omicron variant became dominant, and compares to around 68% between March and August when Delta was the main strain circulating in Scotland. 

The remainder are patients 'with' Covid who have tested positive for the virus but are in hospital for other reasons. 

However, in most cases it was not known which variant had caused the patients' infections.

The Herald:

PHS noted that there were "a disproportionately greater number of older people in hospital ‘because of’ COVID19 compared to ‘with’ COVID-19", adding: "People aged 65 and older account for 42% of all hospital admissions ‘because of’ Covid-19 but just 26% of all admissions ‘with’ Covid-19."

It comes amid evidence that the Omicron variant may cause milder disease, although it is still unclear whether that will remain the case as it increasingly spreads among the older population.

PHS said it was important to "differentiate between patients in hospital who are admitted to hospital ‘because of’ their Covid-19 as opposed to patients who are admitted to hospital coincident ‘with’ their Covid-19 diagnosis" because "knowing this information can help signal whether population-level changes in public health measures may be warranted, such as a tightening or easing of restrictions".

The report adds: "It can also help us to predict whether we are likely to see future pressures on hospital systems based on recent patterns of infections in the surrounding community."

By the week ending December 28, the proportion of people who were ending up in hospital within 14 days of a positive Covid test had fallen to one per cent. 

The Herald:

That compares to a high of 12% in January last year - before mass vaccination - but it is also down from around 4% at the end of October when Delta was still dominant. 

Again, it is unclear whether this reflects the impact of boosters, a decline in the virulence of Covid as a result of Omicron, or infections having occurred predominantly among a younger demographic. 

The Omicron variant now makes up more than 90% of cases in Scotland, based on the prevalence of samples with an S-gene dropout - an genomic marker associated with Omicron, but not Delta. 

In most cases, it is unknown which variant has caused a patient's infection.

However, where a variant type was distinguised through S-gene surveillance, PHS found that Omicron was more prevalent among hospital patients in the GGC region than Grampian: in GGC it accounted for eight out of 11 (73%) hospital admissions compared to six out of 23 (21%) in Grampian. 

The report states: "It is likely that this difference reflects the early patterns of transmission of the Omicron variant in Scotland, which saw the earliest outbreaks in the Greater Glasgow and Clyde area in early December 2021.

"By 12 December 2021, more than half of all people testing at Pillar 2 UK Gov labs in the Greater Glasgow and Clyde region were likely infected by the Omicron variant, whilst in Grampian, that threshold wasn’t reached for another week."

The Herald:

When these patients, whose S gene status was known, were compared, the analysis found that 79% of those with suspected Omicron were in hospital 'because of' their infections compared to 46% 'because of' Delta - which would appear to contradict claims that Omicron is milder. 

However, the report stressed that the data is "limited" - 86 patients were of unknown variant type, for example - and "these numbers are too small to draw any substantial conclusion about whether people are more likely to be in hospital ‘because of’ or ‘with’ the Omicron or Delta variant and any further investigations will have to consider other potential explanatory factors, including prevalence of the variant in the surrounding population and vaccine status." 

The report shows a steady increase in Covid hospital admissions - of any type, and combining both incidental and 'because of' patients - since mid-December. 

During the week ending December 28, a total of 653 patients were admitted to hospital with a positive Covid test.

This included 136 patients over 80, up from 56 in the week ending December 14.

Those over 80 have seen the sharpest increase of any age group.

The Herald:

The report also details Covid admissions by vaccine status. 

It shows that, in the week ending December 17, there were 49 Covid hospital admissions in patients who had received boosters or third vaccine doses; 140 for those who were double-vaccinated; and 76 among those who were unvaccinated. 

The Herald:

However, the age-standardised rate of admission per 100,000 - which adjusts for the different sizes and age demographics of each group - found that the unvaccinated were more than 12 times as likely to be hospitalised with Covid compared to the boosted. 

The admission rate for the unvaccinated was 34.5 per 100,000 compared to 2.8 per 100,000 for those who had had a booster or third dose. 

Those who had only received two doses were also substantially more likely to end up in hospital - with an admission rate of 29.7 per 100,000.

These figures do not distinguish between Covid admissions 'because of' the disease and 'incidental' Covid, however.

And, again, the figures do distinguish between Omicron-related and Delta-related admissions.