One in two people hospitalised with Covid-19 developed at least one complication, research shows.
A study of more than 70,000 patients found the most common complications included renal, respiratory and circulatory problems.
Cardiovascular, neurological, and gastrointestinal and liver complications were also reported in the study, which involved 302 UK hospitals.
These complications are likely to have important short and long-term impacts for patients and put additional strain on healthcare systems, experts claim.
A large national research team of doctors, nurses and medical students, including researchers from the University of Edinburgh, say it is the most comprehensive study of its kind.
It is the first to assess systematically a range of in-hospital complications, and their associations with age, sex and ethnicity, as well as their outcomes for patients.
Experts looked at cases between 17 January and 4 August 2020 before vaccines were widely available and new variants of the virus had arisen.
Complications occurred in 50 per cent of all participants, including in 44 per cent of those who survived. Almost one in three study participants – 32 per cent – died.
Some 56 per cent of study participants were men – 81 per cent had an underlying health condition and 74 per cent were of White ethnicity. The average age was 71.
The incidence of complications rose with increasing age, occurring in 39 per cent of 19 to 49 year olds, compared with 51 per cent of people aged 50 and older.
Complications were more common in men compared with women. Men over 60 were the most likely group to have at least one complication.
People of White, South Asian, and East Asian ethnicities had similar rates of complications. Rates were highest in Black people, Some 58 per cent of Black patients experienced a complication compared with 49 per cent of White patients.
Our research looked at a wide range of complications, and found that short-term damage to several organs is extremely common in those treated in hospital for Covid-19. People who have complications will often need expert care and extra help to recover from their initial hospital admission.
The team says policymakers must consider the risk of complications for Covid-19 survivors – not just mortality – when making decisions on easing restrictions.
Our results can inform public health messaging on the risk Covid-19 poses to younger, otherwise healthy, people – particularly in terms of the importance of vaccination for this group.
This work contradicts current narratives that Covid-19 is only dangerous in people with existing comorbidities and the elderly. Disease severity at admission is a predictor of complications even in younger adults, so prevention of complications requires a primary prevention strategy, meaning vaccination.
The study, published in The Lancet, was funded by the National Institute for Health Research and the UK Medical Research Council.
Edinburgh researchers were part of a team that included the Universities of Liverpool, Sheffield, Glasgow, Oxford, and Nottingham, Public Health England, the Department of Health and Social Care and Imperial College London.