More than half of people hospitalized with Covid-19 still have at least one symptom two years after they were first infected, according to the longest follow-up study of its kind.
While physical and mental health generally improve over time, the analysis suggests that coronavirus patients discharged from hospital still tend to experience poorer health and quality of life than the general population. The research was published in the Lancet Respiratory Medicine.
“Our findings indicate that for a certain proportion of hospitalized Covid-19 survivors, while they may have cleared the initial infection, more than two years is needed to recover fully,” said the lead author, Prof Bin Cao, of the in China.
Until now, the long-term health effects of Covid-19 have remained largely unknown, as the longest follow-up studies to date have spanned about a year. The absence of pre-Covid-19 health status data and comparisons with the general population in most studies also made it difficult to determine how well patients with Covid-19 have recovered.
For the new study, researchers sought to analyze the long-term health outcomes of hospitalized Covid-19 survivors, as well as specific health impacts of long Covid. They evaluated the health of 1,192 participants with acute Covid-19 treated at Jin Yin-tan Hospital in Wuhan, China, between 7 January and 29 May 2020, at six months, 12 months and two years. The average age was 57 at discharge.
Assessments involved a six-minute walking test, laboratory tests, and questionnaires on symptoms, mental health, health-related quality of life, whether they had returned to work and healthcare use after discharge. Health outcomes at two years were determined using an age, sex and comorbidities-matched control group of people in the general population with no history of Covid-19 infection.
Six months after initially falling ill, 68% of the patients reported at least one long Covid symptom. Two years after infection, more than half – 55% – still reported symptoms. Fatigue or muscle weakness were those most often reported. Regardless of the severity of their initial illness, two years later, one in 10 patients – 11% – had not returned to work.
Two years after initially falling ill, the patients were in poorer health than the general population, with 31% reporting fatigue or muscle weakness and 31% reporting sleep difficulties. The proportion of non-Covid-19 participants reporting these symptoms was 5% and 14% respectively. The Covid-19 patients were also more likely to report a number of other symptoms including joint pain, palpitations, dizziness and headaches. In quality of life questionnaires, Covid-19 survivors also more often reported pain or discomfort and anxiety or depression than non-Covid-19 participants.
The authors acknowledged limitations to their study. Being a single-centre study from early in the pandemic, the findings may not directly extend to the long-term health outcomes of patients infected with subsequent variants, the Lancet Respiratory Medicine said. Like most Covid-19 follow-up studies, there is also the potential for information bias when analyzing self-reported health outcomes.
“Ongoing follow-up of Covid-19 survivors, particularly those with symptoms of long Covid, is essential to understand the longer course of the illness, as is further exploration of the benefits of rehabilitation programs for recovery,” said Cao. “There is a clear need to provide continued support to a significant proportion of people who’ve had Covid-19, and to understand how vaccines, emerging treatments and variants affect long-term health outcomes.”