However, the follow-up time of similar studies was relatively short, no more than 1 year. Moreover, in most studies, the lack of pre-infection health baselines and lack of comparison with the general population also makes it difficult to determine the recovery of COVID-19 patient

Chief Reporter of The Paper He Liping

As the COVID-19 pandemic continues, more and more clinical and research evidence shows that a considerable proportion of COVID-19 recovered patients have had long-term impacts. However, the follow-up time of similar studies was relatively short, no more than 1 year. Moreover, in most studies, the lack of pre-infection health baselines and lack of comparison with the general population also makes it difficult to determine the recovery of COVID-19 patients. A new study by the Chinese team reported on the longitudinal evolution of health outcomes of survivors of different severity of COVID-19 infection within 2 years after acute COVID-19 infection. This longest follow-up study of COVID-19 patients to date was completed by a team led by Professor Cao Bin of Sino-Japanese Friendship Hospital and Professor Wang Jianwei of Peking Union Medical College of Chinese Academy of Medical Sciences. The study, published online on May 12, Beijing time in Lancet Respiratory Medicine, entitled "Health outcomes in people 2 years after surviving hospitalisation with COVID-19: a longitudinal cohort study."

Cao Bin said, "Our results show that for a certain percentage of COVID-19 hospitalized survivors, although they may have cleared the initial infection, it will take more than 2 years to fully recover from COVID-19." He stressed that the ongoing follow-up of COVID-19 survivors, especially those with long COVID-19 symptoms, is crucial to understanding the longer course of the disease, and further exploration of rehabilitation plans is also crucial for recovery.

Cao Bin also reminded that there is a need to continue to provide support to a large proportion of COVID-19 patients and understand how vaccines, emerging treatments and coronavirus mutants affect long-term health outcomes.

study mentioned that from January 7, 2020 to May 29, 2020, a total of 2,469 COVID-19 patients were discharged from Wuhan Jinyintan Hospital. Of these, 1192 survivors were evaluated and included in the final analysis at three follow-up visits, of which 1119 (94%) were interviewed in person 2 years after infection. The follow-up time included 6 months, 12 months and 2 years.

evaluation includes a 6-minute walk test (6MWD), laboratory tests and questionnaires on symptoms, mental health, health-related quality of life (HRQoL), return to work, and medical use after discharge. Identify the impact of long COVID on quality of life, exercise ability, mental health and health care use by comparing participants with and without long COVID symptoms. The 2-year health outcome was determined by a control group matched with age, gender and comorbidity, which was the general population without a history of COVID-19 infection.

The median age of participants at discharge was 57 years (48.0-65.0), of which 551 (46%) were female. The median follow-up time of 6 months after onset was 185.0 days (IQR 175.0-197.0), the median follow-up time of 12 months was 349.0 days (337.0-360.0), and the median follow-up time of 2 years was 685.0 days (675.0-698.0).

study showed that 6 months after the initial onset, 68% (777/1149) of participants reported at least one sequelae; 2 years after infection, this proportion dropped to 55% (650/1190). Among them, fatigue or muscle weakness was the most reported symptoms, from 52% at 6 months (593/1151) to 30% at 2 years (357/1190).

Two years after the initial onset, COVID-19 patients usually have worse health than the general population, with 31% (351/1127) reporting fatigue or muscle weakness and 31% (354/1127) reporting difficulty sleeping. The proportion of non-COVID-19 participants who reported these symptoms was 5% (55/1127) and 14% (153/1127), respectively. COVID-19 patients are also more likely to report some other symptoms, including joint pain, palpitations, , dizziness and headaches.

In the Quality of Life Questionnaire, COVID-19 patients also reported pain or discomfort and anxiety or depression more frequently than non-COVID-19 participants. However, the study also mentioned that health-related quality of life continues to improve in almost all areas, especially in anxiety or depression: the proportion of individuals with anxiety or depression symptoms decreased from 23% at 6 months (256/1105) to 12% at 2 years (143/1191).

Long COVID, fatigue or muscle weakness , anxiety or depression, risk factors for diffuse lung injury. The

study further analyzed that about half of the study participants (650/1190) developed symptoms of long-term COVID within 2 years and reported lower quality of life than those without long-term COVID. Among participants who reported long COVID symptoms, the Mental Health Questionnaire showed that 35% (228/650) reported pain or discomfort and 19% (123/650) reported anxiety or depression. The above two reported rates were 10% (55/540) and 4% (19/540) in patients without symptoms of COVID-19. Patients with symptoms of COVID-19 also reported more often about their mobility (5% [33/650]) or activity level (4% [24/540]) than participants with COVID-19 (1% [8/540] and 2% [10/540], respectively).

study also mentioned that participants in COVID-19 need health care more frequently after discharge, with 26% (169/648) reporting outpatient visits, compared with only 11% (57/538) of participants in COVID-19 (57/538). The hospitalization rate for participants with long-term COVID-19 was 17% (107/648), which was higher than that of participants without long-term COVID-19 (52/538).

In addition, regardless of the initial severity of the disease, 89% (438/494) of the participants returned to their original jobs after 2 years.

It is also worth noting that for 2 years of follow-up, the burden of restricted ventilation disorder and diffuse lung injury in critically ill patients was significantly higher than that in the control group.

research team concluded that regardless of the initial severity of the disease, the physical and mental health of patients discharged from COVID-19 has improved over time, and most people have returned to work within 2 years. However, the burden of symptomatic sequelae remains quite high. These participants had significantly lower health status than the general population after 2 years. They propose that the need to continue follow-up of these populations to determine the long-term natural course of COVID-19. The research team also plans to conduct annual follow-up of the cohort.

research team also reminded that it is urgent to explore the pathogenesis of long-term COVID and formulate effective interventions to reduce the risk of long-term COVID.

Senior editor of this issue Xingtan