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How Long Exactly Is Long COVID?

— Chinese study suggests that for some, it may be measured in years, not months

MedpageToday
An unhappy mature Asian man lies in bed awake in the daytime.

Almost half of patients hospitalized with COVID-19 early in the pandemic had at least one lingering symptom a year after symptom onset, researchers in Wuhan, China found.

A total of 49% of patients had at least one post-COVID symptom 1 year later, which included sleep difficulties, palpitations, joint pain, or chest pain, though that was down significantly from 68% of survivors at 6 months after symptom onset (P<0.0001), reported Bin Cao, MD, of China-Japan Friendship Hospital in Beijing, and colleagues.

Notably, more patients reported anxiety or depression at their 12-month visit than at their 6-month visit (26% vs 23%, respectively, P=0.015) and dyspnea (30% vs 26%, P=0.014), the authors wrote in

The most common symptom was fatigue or muscle weakness, though the authors noted there was a significant decline at the 12-month visit versus the 6-month visit (20% vs 52%, respectively, P<0.0001).

Co-author Xiaoying Gu, MD, also of China-Japan Friendship Hospital, said the authors did not yet understand why psychiatric symptoms were more pervasive at 1 year compared with 6 months.

"These could be caused by a biological process linked to the virus infection itself, or the body's immune response to it. Or they could be linked to reduced social contact, loneliness, incomplete recovery of physical health or loss of employment associated with illness," Gu said in a statement.

The researchers noted that to their knowledge, "this is the largest longitudinal cohort study of hospital survivors with COVID-19" to examine the health effects of the disease 12 months after symptom onset. Previously, Cao's group looked at data from 6 months after symptom onset in COVID-19 survivors from Wuhan.

This single-center study examined data from COVID-19 survivors discharged from January 7 to May 29, 2020. They attended two follow-up visits at 6 months and 12 months after symptom onset.

Overall, 1,276 participants attended both visits. Median age was 59, and 53% were men. Around 70% received oxygen via nasal cannula; 7% required high-flow nasal cannula, non-invasive or invasive mechanical ventilation; and 4% were admitted to the intensive care unit, with a median length of stay of 18.0 days.

There was no significant difference in the proportion of patients with 6-minute walk test scores below normal range at 12 months compared with 6 months (12% vs 14%, P=0.033).

Notably, Cao's group reported that "many symptoms significantly resolved over time" in the total cohort, including sleep difficulties, hair loss, and smell and taste disorder.

"Sequelae symptoms, lung diffusion impairment, and radiographic abnormalities persisted to 12 months in some patients, especially in patients who were critically ill during hospital stay," the researchers said.

While they said it was "worrying" that there was a higher percentage of patients with dyspnea and anxiety or depression at 12 months compared with 6 months, "the increased proportion in our cohort is relatively low."

The team also cited prior research that found that COVID-19 survivors were more likely to use medications and therapies, such as bronchodilators, antitussives, expectorants, antidepressants, and anxiolytics 6 months later.

Limitations to the data, the researchers said, included the single-center design, the potential for bias, and the fact that there were no data on the health status of COVID-19 survivors prior to acute infection.

Cao and colleagues called for more follow-up on COVID-19 survivors through longitudinal studies, and the editors of The Lancet agreed in an .

"[Healthcare] providers must acknowledge and validate the toll of the persistent symptoms of long COVID on patients, and health systems need to be prepared to meet [individualized], patient-oriented goals, with an appropriately trained workforce involving physical, cognitive, social, and occupational elements," the editors stated.

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    Molly Walker is deputy managing editor and covers infectious diseases for ľֱ. She is a 2020 J2 Achievement Award winner for her COVID-19 coverage.

Disclosures

The study was supported by the Chinese Academy of ľֱ Sciences Innovation Fund for ľֱ Sciences, the National Natural Science Foundation of China, the National Key Research and Development Program of China, Major Projects of National Science and Technology on New Drug Creation and Development of Pulmonary Tuberculosis, the China Evergrande Group, the Jack Ma Foundation, Sino Biopharmaceutical, Ping An Insurance (Group), and New Sunshine Charity Foundation.

The authors disclosed no conflicts of interest.

Lancet editors disclosed no conflicts of interest.

Primary Source

The Lancet

Huang L, et al "1-year outcomes in hospital survivors with COVID-19: a longitudinal cohort study" Lancet 2021; 398: 747-58.

Secondary Source

The Lancet

Lancet editors "Understanding long COVID: a modern medical challenge" Lancet 2021; 398: 725.