The majority of survivors who left hospital following COVID-19 did not fully recover five months after discharge.
According to results released by the the Post-hospitalisation COVID-19 (PHOSP-COVID) study, patients continued to experience negative impacts on their physical and mental health, as well as ability to work. Furthermore, at least a fifth of the participant population reached the threshold for a new disability.
The UK-wide study is jointly funded by UK Research and Innovation and the National Institute for Health Research (NIHR). It analysed 1077 patients who were discharged from hospital between March and November 2020 following an episode of COVID-19.
The NIHR’s Leicester Biomedical Research Centre found that 74% of patients had at least one persistent symptom, with each participant having an average of eight. The centre is a partnership between:
- Leicester’s hospitals
- University of Leicester
- Loughborough University.
The 10 most common symptoms reported were:
- muscle pain
- physical slowing down
- impaired sleep quality
- joint pain or swelling
- limb weakness
- short-term memory loss
- slowed thinking.
Patients were also assessed for mental health. The study reports that over 25% of participants had clinically significant symptoms of anxiety and depression, and 12% had symptoms of post-traumatic stress disorder (PTSD) at their five month follow-up.
Of the 68% of participants who were working before COVID, one in five were no longer working, and 20% experienced a health-related change in their occupational status.
‘Clusters’ of patients most at risk
Professor Chris Brightling, a professor of respiratory medicine at the University of Leicester and the chief investigator for the PHOSP-COVID study, said:
While the profile of patients being admitted to hospital with COVID-19 is disproportionately male and from an ethnic minority background, our study finds that those who have the most severe prolonged symptoms tend to be white women aged approximately 40 to 60 who have at least two long term health conditions, such as asthma or diabetes.
The researchers were able to classify types of recovery into four different groups or ‘clusters’ based on the participants’ mental and physical health impairments.
One cluster group in particular showed impaired cognitive function, or what has colloquially been called ‘brain fog’. Patients in this group tended to be older and male. Cognitive impairment was striking even when taking education levels into account, suggesting a different underlying mechanism compared to other symptoms.
Not explained by severity of illness
Dr Rachael Evans, an associate professor at the University of Leicester and respiratory consultant at Leicester’s hospitals, said:
Our results show a large burden of symptoms, mental and physical health problems and evidence of organ damage five months after discharge with COVID-19. It is also clear that those who required mechanical ventilation and were admitted to intensive care take longer to recover. However, much of the wide variety of persistent problems was not explained by the severity of the acute illness – the latter largely driven by acute lung injury – indicating other, possibly more systemic, underlying mechanisms.
Potential biological factor at play
The research has also uncovered a potential biological factor behind some post-COVID symptoms.
Professor Louise Wain, GSK/British Lung Foundation Chair in Respiratory Research at the University of Leicester and co-investigator for the PHOSP-COVID study, said:
When we looked at the symptom severity of patients five months after they were discharged from hospital, we found that in all but the mildest cases of persistent post-COVID symptoms, levels of a chemical called C-reactive protein (CRP), which is associated with inflammation, were elevated.
From previous studies, it is known that systemic inflammation is associated with poor recovery from illnesses across the disease spectrum. We also know that auto-immunity, where the body has an immune response to its own healthy cells and organs, is more common in middle-aged women. This may explain why post-COVID syndrome seems to be more prevalent in this group, but further investigation is needed to fully understand the processes.
The evidence for different recovery ‘clusters’, and ongoing inflammation, really is important in guiding how we conduct further research into the underlying biological mechanisms that drive ‘Long-COVID’.
One of the purposes of the PHOSP-COVID study is to measure the impact of medicines given during hospitalisation to see if they affect patients’ recovery. Early indicators from the study show that while giving corticosteroids is a factor in reducing mortality in hospital, it does not appear to have an impact on longer term recovery.
There are more than 300,000 post-hospitalisation survivors in the UK that have been discharged from hospital following COVID-19. The study only represents a small sample of these patients, and participants are younger than the whole population in the UK that survived hospitalisation for COVID-19 infection. However, this is the largest study to report in detail on prospectively assessed outcomes across multiple UK centres to describe the impact of COVID-19 on medium term health of survivors.
Professor Fiona Watt, Executive Chair of the Medical Research Council, said:
The initial findings from this study are that most patients hospitalised with COVID-19 are still suffering from effects of the disease five months on. Whilst this is clearly a concern, the new findings will help pave the way to improving patient recovery. The more we understand about what risk factors make someone less likely to recover fully, the better care and treatment we can offer to those patients who need it most.
Professor Brightling added:
Our findings support the need for a proactive approach to clinical follow-up with a holistic assessment to include symptoms, mental and physical health, but also an objective assessment for cognition. The four severity clusters highlight potential to stratify care, but also the need for wide-access to post-COVID19 holistic clinical services to include mental health, memory and cognition, and rehabilitation services.
Continued study of the trajectory of recovery over a longer timeframe, coupled with greater understanding of the biology underpinning post-COVID symptoms, will further inform approaches to the clinical management post-COVID19 infection. As such, patients in the study will be assessed again at 12 months to help gather more data to support this learning.
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