• Less than 3 in 10 patients may be fully recovered a year after being hospitalised with Covid-19
• Those who were female, obese, and required invasive mechanical ventilation during their hospital stay were least likely to make a full recovery
• Results suggest the physical and mental health impairments reported are unlikely to be the result of pre-existing conditions
Long-Covid patients show limited recovery one year after being discharged from hospital, according to the latest results of the UK-wide PHOSP-COVID study.
The University of Dundee’s Professor James Chalmers, who represents Scotland on the PHOSP-COVID study management board, said the results showed the urgent need to develop new treatments for Long-Covid patients.
People who were hospitalised with Covid-19 and continued to experience symptoms at five months were not getting substantially better a year after discharge, according to the study. It also confirmed earlier research that people who were less likely to make a full recovery from Covid-19 were female, obese, and required invasive mechanical ventilation to support their breathing during their hospital stay.
PHOSP-COVID is led by the National Institute for Health Research (NIHR) Leicester Biomedical Research Centre – a partnership between Leicester’s Hospitals, the University of Leicester and Loughborough University – and jointly funded by the NIHR and MRC-UK Research and Innovation (UKRI).
Researchers from 53 institutions and 83 hospitals across the UK assessed 2,230 adults who had been hospitalised with Covid-19. All participants completed a five-month assessment. So far, 807 people have completed both the five-month and 12-month assessments. Recovery was measured using patient-reported data, physical performance and organ function tests. Participant blood samples at the five-month visit were analysed for around 300 substances linked to inflammation and immunity.
They found that one year after hospital discharge, less than 3 in 10 patients on the study reported they felt fully recovered, largely unchanged from 2.5 in 10 at five months. The most common ongoing symptoms were fatigue, muscle pain, physically slowing down, poor sleep and breathlessness.
Participants felt their health-related quality of life remained substantially worse one year after hospital discharge, compared to pre-Covid. This suggests the physical and mental health impairments reported in the study are unlikely to be pre-existing conditions.
Professor Chalmers said, “There is a clear need for a national programme of action to develop new support and treatments for patients experiencing Long-Covid. Until now, there has understandably been a focus on patients presenting with acute Covid-19, particularly those who are hospitalised or who require intensive care.
“That has meant a lot of patients with Long-Covid have felt forgotten, but these results show that it is important that we do not let this happen. This is a really nasty, chronic condition and there is an urgent need for more treatments that can help.
“More positively, this is the first study that has looked in detail at what causes Long-Covid. Identifying that an ongoing inflammatory process is at work means we have a potential starting point for developing new treatments that target this inflammation.”
Four distinct groups were identified based on the severity of physical, mental and cognitive impairments experienced at five months. The number of persistent symptoms was much higher in the ‘very severe’ group compared to the ‘mild’ group. In all these clusters, there was little improvement in physical and mental health from the five-month to one-year assessments.
The researchers compared the blood profiles across the four clusters. They identified higher levels of substances associated with whole-body inflammation and molecules associated with tissue damage and repair, in participants with very severe Long-Covid compared to mild. They also found a pattern of substances linked to poor cognition in the cluster of patients reporting symptoms such as ‘brain fog’ or slowed thinking, suggesting possible neuro-inflammation.
Professor Chris Brightling, NIHR Senior Investigator and Professor of Respiratory Medicine at the University of Leicester, and Chief Investigator for the PHOSP-COVID study, said, “Our findings show that people who were hospitalised and went on to develop Long-Covid are not getting substantially better a year after they were discharged from hospital.
“Many patients in our study had not fully recovered at five months and most of these reported little positive change in their health condition at one year. When you consider that over half a million people in the UK have been admitted to hospital as a result of Covid-19, we are talking about a sizeable population at risk of persistent ill-health and reduced quality of life.”
The consortium acknowledges that there may be self-selection bias in the patients returning for one-year visits, although from the data it appears that there are no clear differences between the patients attending the one-year follow-up and the larger participant population in the wider study, including their recovery at five months.
Assuming all the participants who had missing data at one year had either not recovered or were fully recovered, the adjusted figures are 2 in 10 or 6 in 10 people recovering from Covid-19 at one year, respectively.
The PHOSP-COVID study is available as a pre-print on medRxiv, which means it is yet to be peer reviewed by other scientists.