Study population and setting
This ambidirectional cohort study characterized one-year health outcomes among COVID-19 survivors who were discharged from a single center in Wuhan, China between January and May of 2020. Participants attended study visits six and twelve months after hospital release. Each visit included a physical examination, detailed interviews, health questionnaires, and laboratory tests. A subset of participants also underwent pulmonary function testing and a chest CT. Data were compared between visits and to healthy controls recruited from the local community, matched 1:1 for age, sex, and relevant comorbidities.
Summary of Main Findings
Of 2,469 COVID-19 survivors eligible for study inclusion, 1,276 (58%) voluntarily participated in both follow-up visits and were included in this analysis. During hospitalization, 68% (864/1,276) participants required supplemental oxygen, 7% (86/1,276) required treatment with high-flow nasal cannula and/or non-invasive ventilation (i.e., CPAP, BiPAP), 1% (8/1,276) required mechanical ventilation and/or ECMO, and 4% (54/1,276) were admitted to the ICU. At the six-month visit, at least one persistent symptom was identified in 68% (831/1227) of participants; this proportion dropped to 49% (620/1272) by the twelve-month visit. Fatigue/muscle weakness (52% at six months; 20% at twelve months) was the most reported symptom. The prevalence of both dyspnea and anxiety/depression increased slightly between the six- and twelve-month visits (from 26% to 30%, and 23% to 26%, respectively). By twelve months, most participants had normal pulmonary function testing, as well as improvement in any prior abnormalities visualized on CT (i.e., ground glass opacities). However, some participants with a more severe hospital course had persistent lung diffusion defects and radiographic abnormalities. Of participants who had been employed prior to their illness, 88% (422/479) had returned to work at twelve months. General health problems (i.e., mobility issues, pain, mental health concerns) were more frequent at twelve months among COVID-19 survivors compared to matched controls (66% vs. 33%).
This is the largest longitudinal cohort study of COVID-19 survivors following hospitalization. Outcomes were quantified based on multiple data sources, including physical exam, self-report measures, and laboratory results. Outcomes were compared to healthy controls from the local community, matched 1:1 for relevant comorbidities and demographic data.
Moderate rate of study participation (58%) among eligible participants may have introduced sample bias, though there were no significant differences in measured baseline characteristics between eligible and participating groups. All participants were enrolled from a single center, and results may not be representative of the general population. Additionally, patients were excluded from study participation if they died following hospital release, were discharged to a nursing home, or had significant physical limitations that prevented normal mobility; as such, this study may not adequately quantify the risk of long-term health consequences following COVID-19 hospitalization. Researchers did not have access to data on the health status of participants prior to infection, which may have confounded results, as participants may have had an increased risk of severe COVID-19 due to factors not considered in control group matching. Furthermore, cases were hospitalized with COVID-19 and controls were from the local community. Despite matching on important variables, hospitalization, especially intensive care unit admission, is likely associated with persistent symptoms. The control group therefore does not provide a baseline level of persistent symptoms after hospitalization for non-COVID-19 illness. Importantly, participants were infected in the early phases of the pandemic and before the rise of the Delta variant. At the time, providers were still identifying best practices for the management of COVID-19 patients, which may have negatively impacted both disease course and long-term health complications. Finally, the early public health response to COVID-19 in China mandated hospitalization for all infected individuals, including those with no or only minor symptoms. As such, this cohort may not be adequately representative of hospitalized patients with moderate to severe COVID-19 disease.
This is the largest longitudinal study of hospitalized COVID-19 survivors that measures long- term health consequences up to a year after infection.
This review was posted on: 26 October 2021