Long COVID study finds 90% still impacted after 12 months
A survey of nearly 1,000 long COVID patients has found 89% of respondents have not returned to their pre-COVID level of health, a year after their acute infection. The study highlights the persistent lingering impact COVID is having on many people.
The new research, led by a team from University College Cork, surveyed 988 long COVID patients in Ireland. Less than 10% of the cohort suffered a severe acute COVID infection requiring hospitalization. Instead, 62% reported their initial infection to be mild or moderate.
Although most of the respondents reported their health had not returned to normal since their acute infection, only a small amount were still significantly incapacitated. Just under 40% of those surveyed said their long COVID symptoms still affected their ability to work, and 16% of participants were currently receiving welfare payments due to their illness.
"This survey highlights that SARS-CoV-2 infection not only impacts the lungs but can have significant long-term effects on multiple organ systems following clearance of the acute SARS-CoV-2 infection in many Irish people who were otherwise healthy previously," said Liam O'Mahony, one of the lead researchers on the project. "A wide range of body systems are impacted by long COVID, as demonstrated by systemic, respiratory, cardiovascular, gastrointestinal, neuropsychiatric or musculoskeletal symptoms. Fatigue is the single most frequent symptom reported.”
The findings echo a 2021 study tracking the long-term impact of long COVID in more than 3,500 people from 56 countries. That research was limited to a 35-week follow-up but it found 91% of patients had not returned to their baseline levels of health seven months after the acute infection.
One potential problem with these kinds of retrospective patient surveys is they can be biased towards those patients experiencing the most severe long COVID effects. The authors of the 2021 study flag this problem, suggesting these kinds of findings may not be entirely representative of all long COVID experiences.
"As the survey was distributed in online support groups, there exists a sampling bias toward long COVID patients who joined support groups and were active participants of the groups at the time the survey was published," the researchers behind last year's study explained. "The effort to complete the survey may have deterred some respondents who experienced cognitive dysfunction, or were no longer ill and did not have incentives to participate."
A more recent study, from University of Glasgow researchers, perhaps offers a more tempered investigation into the persistence of long COVID. That research, published in Nature Communications, followed more than 30,000 confirmed COVID cases in Scotland for up to 18 months after their acute infection.
At their most recent follow-up, between six and 18 months after infection, 42% of patients reported they only felt "partially recovered." A striking 6% of respondents reported not feeling better at all after at least six months.
"While there remains a huge amount to learn about post COVID illness, there is a clear and compelling need for dedicated cross disciplinary specialist services to treat long COVID patients," said Corinna Sadlier, one of the researchers working on the University College Cork study. "In parallel, research is urgently required to identify mechanisms underlying long COVID symptoms as well as effective treatments to improve outcomes for this patient group.”
The new study was published on HRB Open Research.
Source: University College Cork