Patients and study design
Only COVID-19 patients who met all the following
criteria(National_Health_Commission_of_China, 2020 ) could be
discharged from the hospital and admitted to the follow-up study
project: (1) body temperature returned to normal for more than 3
consecutive days, (2) had significant improvement in any symptom, such
as fever, dry cough and expectoration, (3)
had
substantial improvement in acute exudative lesions on chest computed
tomography (CT) images, and (4) had negative RT-PCR test results for
SARS-CoV-2 RNA from a nasopharyngeal swab, an anal swab or other
respiratory specimens two consecutive times (at least 24 hours apart).
Between January 30, 2020, and September 9, 2020, a total of 745 patients
who officially recovered from COVID-19 were discharged from the hospital
and enrolled in this study in Guangzhou, China. All discharged patients
were required to undergo 14 days of quarantine in designated health care
facilities and 28 days of community follow-up to observe their clinical
symptoms and RT-PCR results. The positive retest patients were
re-admitted to the hospital for therapy, and close contacts were traced
and followed-up. The remaining discharged patients who continued to have
negative RT-PCR test results were closely followed-up in their
communities. Fig. 1 shows the flowchart of the management of
discharged patients.
This study was reviewed and approved by the Ethics Committee of the
Guangzhou CDC (GZCDC). As required by the National Health Commission of
China, CDCs were responsible for the work for an ongoing public health
response to COVID-19, and our cohort study was based on the data from
the GZCDC. Patients were informed about the surveillance before
providing written consent, and data were collected and anonymized for
analysis. All analyses of personally identifiable data took place onsite
at the GZCDC.