Methods
Study Design and Inclusion Patients
This study was approved by the research ethics committee Mazandaran
University of Medical Sciences, Sari, Iran (IR.MAZUMS.REC.1399.7418).
All patients who were admitted to Emam Khomeini hospital, Sari,
Mazandaran from February 26, 2020, to September 21, 2020, were included.
The written informed consent was given up from all participants with
COVID-19 infection. Simple random sampling was used for including
patients. The diagnosis, hospitalization, and treatment of patients was
performed according to Iran’s Ministry of Health and Medical Education
guidelines. Iranian guidelines mentioned the laboratory and radiological
examinations as a first line of COVID-19 confirmation along with
clinical symptoms such as fever, cough, and shortness of breath. The
cases without chest CT and laboratory test confirmation were excluded.
Assuming 95% confidence level and p=0.7 (lymphopenia 70%), d= 0.07,
and Cochran’s formula the sample size was calculated as 596. Clinical
outcomes including CBC, CRP, and ESR were evaluated within a 7-days
monitoring period. All medical data including epidemiological,
demographic, laboratory data, and patient’s discharge and/or death were
extracted via the hospital information system (HIS).
CT scans
All CT examinations were performed using a multi‐detector computed
tomography scanner (CT-Scan) Somatom Emotion eco (16‐slice
configuration, Siemens, Erlangen, Germany). The supine CT scan was
performed and no contrast medium had been administrated. The CT images
were observed with both lungs and in parenchymal and mediastinal window
settings. Two radiologists appraised the lung scans by the picture
archiving and communication system (PACS, INFINITT Healthcare co., Ltd.,
Seoul, Korea). The features of CT imaging were typically focused on
unilateral and bilateral Ground Glass Opacity (GGO), consolidation, and
pleural effusion. The pulmonary involvement of COVID-19 patients was
categorized into two groups: less than 50% (Figure 1-A) and more than
50 % involvement (Figure 1-B). Clinical data were screened on the date
of symptom onset and 7th day and abstracted from the
medical records of Imam Khomeini hospital, Sari, Iran. All data
containing age, sex, underlying medical conditions, CT scan results,
lymphocyte count, CRP, ESR, Platelet, length of stay (LOS), and
mortality was recorded according to the checklist. Data analysis was
performed using SPSS, and Mann-Whitney and Kruskal-Wallis tests. The
logistic regression model interprets the odds ratio and P
<0.05 was considered as statistically significant.