General information
145 patients with severe and critical COVID-19 were set as the severe group and 147 patients with common COVID-19 were set as the mild group. Compared to mild group, patients in severe group were more likely to be male (63.9% vs 38.1%, P < 0.001)and older (67.97 ± 12.69 vs 54.14 ± 13.62, P < 0.001). There were more smokers (8.84% vs 1.36%, P = 0.006) and drinkers (4.08% vs 0%, P = 0.0297) in the severe group than in the mild group. Meanwhile, patients in severe group had more comorbidities such as Hypertension(48.97% vs 23.81%, P < 0.0001)(), coronary heart disease (22.07% vs 1.36%, P < 0.0001) ,chronic obstructive pulmonary disease (6.21% vs 1.36%, p = 0.0342),malignant tumor (7.59% vs 2.04%, P = 0.0301) and chronic kidney disease (3.45% vs 0% P = 0.0291) than that in the mild group. Details of other relevant information were shown in Table 1.
Table 1
Clinical features of COVID-19 between mild and severe groups
Variables | Mild group | Severe group | P value |
Age, years, mean (sd) | 54.14 (13.62) | 68.19 (12.51) | < 0.0001 |
Male, n (%) | 56 (38.1%) | 92 (63.45%) | < 0.0001 |
BMI, kg/m2, mean (sd) | 23.96 (2.04) | 24.42 (2.02) | 0.1163 |
Smoking history, n (%) | 2 (1.36%) | 13 (8.97%) | 0.0032 |
Drinking history, n (%) | 0 (0%) | 6 (4.14%) | 0.0142 |
Comorbidities, n (%) | | | |
COPD | 2 (1.36%) | 9 (6.21%) | 0.0342 |
Asthma | 1 (0.68%) | 0 (0%) | 1.0000 |
Hypertension | 35 (23.81%) | 71 (48.97%) | < 0.0001 |
CHD | 2 (1.36%) | 32 (22.07%) | < 0.0001 |
Diabetes | 16 (10.88%) | 28 (19.31%) | 0.0503 |
Malignantbtumor | 3 (2.04%) | 11 (7.59%) | 0.0301 |
CKD | 0 (0%) | 5 (3.45%) | 0.0291 |
CLD | 0 (0%) | 4 (2.76%) | 0.0595 |
Symptoms, n (%) | | | |
Chest tightness | 65 (44.22%) | 97 (66.9%) | < 0.0001 |
Dry cough | 79 (53.74%) | 96 (66.21%) | 0.0322 |
Fever | 118 (80.27%) | 117 (80.69%) | 1.0000 |
Running nose | 2 (1.36%) | 4 (2.76%) | 0.4459 |
Sore throat | 0 (0%) | 3 (2.07%) | 0.1212 |
Sputum | 29 (19.73%) | 32 (22.07%) | 0.6671 |
Dyspnea | 34 (23.13%) | 63 (43.45%) | < 0.0001 |
Fatigue | 101 (68.71%) | 111 (76.55%) | 0.1497 |
Anorexia | 98 (66.67%) | 104 (71.72%) | 0.3765 |
Muscle ache | 36 (24.49%) | 34 (23.45%) | 0.8913 |
Nausea | 12 (8.16%) | 8 (5.52%) | 0.4882 |
Diarrhea | 14 (9.52%) | 5 (3.45%) | 0.0552 |
Headache | 10 (6.8%) | 15 (10.34%) | 0.3027 |
Days from onset to admission, days, median (IQR) | 5 (4, 7) | 5 (3, 8) | 0.7166 |
Abbreviations:BMI: Body mass index; COPD: Chronic obstructive pulmonary disease; CHD: Coronary heart disease; CKD: Chronic kidney disease; CLD: Chronic liver disease; IQR: Inter quartile range |
Regarding clinical symptoms, the dyspnea, chest tightness and dry cough were more common in severe group (43.45%, 66.9% and 66.21%) than in mild group (23.13%, 44.22% and 53.74%). Details of other relevant information were shown in Table 1.
Laboratory test results
After admission, the first blood routine, biochemical, immune and coagulation tests were performed in the two groups. We observed substantial differences in laboratory findings in the two groups (Table 2).
Table 2
Laboratory test resultsof COVID-19 between mild and severe groups
Variables | Mild group | Severe group | P value |
CRP,median(IQR),mg/L | 14.96 (3.95, 41.16) | 61.77 (23.03, 110.3) | < 0.0001 |
LY,median(IQR),109/L | 1.11 (0.74, 1.46) | 0.72 (0.5, 1.05) | < 0.0001 |
MO,median(IQR),109/L | 0.38 (0.27, 0.52) | 0.33 (0.22, 0.49) | 0.1372 |
NE,median(IQR),109/L | 3.19 (2.27, 4.44) | 4.84 (3.38, 7.47) | < 0.0001 |
WBC,median(IQR),109/L | 5.08 (3.71, 6.08) | 6.14 (4.71, 8.68) | < 0.0001 |
PLT,,median(IQR),109/L | 211 (163.5, 280) | 170 (135, 241) | < 0.0001 |
Hb, median(IQR), g/L | 125 (115, 138) | 128 (117, 140) | 0.3052 |
RBC,median(IQR),1012/L | 4.13 (3.78, 4.54) | 4.19 (3.87, 4.63) | 0.3186 |
PCT,median(IQR),ng/ml | 0.02 (0.02, 0.05) | 0.08 (0.04, 0.23) | < 0.0001 |
SAA,median(IQR), mg/L | 114.65 (19.41, 300) | 300 (153.03, 300) | < 0.0001 |
IL-1, median(IQR),pg/ml | 5 (5, 5) | 5 (5, 6.5) | 0.0001 |
IL-6,median(IQR),pg/ml | 6.12 (3.85, 13.1) | 15.3 (9.8, 25.9) | < 0.0001 |
IL-10,median(IQR),pg/ml | 5 (5, 6.15) | 10.1 (6.7, 14.2) | < 0.0001 |
CD4་T, median(IQR), /ul | 366 (268.5, 439.5) | 136 (93, 196) | < 0.0001 |
CD8་T, median(IQR), /ul | 231 (154.5, 300.5) | 91 (63, 152) | < 0.0001 |
TotalTcell, median(IQR),/ul | 652 (485, 750.5) | 235 (180, 373) | < 0.0001 |
ALT, median(IQR),U/L | 19 (10.5, 35) | 26 (16, 44) | 0.0006 |
AST, median(IQR),U/L | 22 (18, 32.5) | 33 (24, 50) | < 0.0001 |
ALP, median(IQR),U/L | 56 (44.5, 70) | 66 (51, 80) | 0.0004 |
GGT,median(IQR),U/L | 25 (18, 42) | 37 (23, 52) | 0.0001 |
ALB, median(IQR),g/L | 36.5 (34.25, 40.2) | 33.8 (30.7, 36.6) | < 0.0001 |
TB, median(IQR), umol/L | 10.1 (7.45, 13.5) | 12.7 (9.5, 17.1) | < 0.0001 |
DB, median(IQR), umol/L | 1.9 (1.2, 2.7) | 3.2 (2.2, 4.6) | < 0.0001 |
D-dimer,median(IQR),mg/L | 0.5 (0.34, 0.8) | 1 (0.62, 5.43) | < 0.0001 |
Fibrinogen,median(IQR), g/L | 3.16 (2.61, 4.06) | 3.92 (3.25, 4.34) | < 0.0001 |
PT, median(IQR), S | 12.5 (12, 13.35) | 13.2 (12.6, 14.3) | < 0.0001 |
APTT, median(IQR), S | 30 (27.8, 33.05) | 30 (28, 32.2) | 0.9818 |
CK, median(IQR), U/L | 54 (31.5, 93.5) | 116 (60, 240) | < 0.0001 |
HBDB,median(IQR),U/L | 170 (135.5, 216) | 297 (220, 394) | < 0.0001 |
LDH, median(IQR), U/L | 216 (180, 268) | 347 (262, 495) | < 0.0001 |
BUN,median(IQR),mmol/L | 4.09 (3.2, 5.53) | 6.4 (4.92, 8.37) | < 0.0001 |
Cr, median(IQR), umol/L | 63.2 (55.15, 77.65) | 79.7 (62.4, 98.2) | < 0.0001 |
Abbreviations: CRP:C-reactive protein; LY: Lymphocyte; MO: Monocyte; NE: Neutrophil; WBC:White blood cells; PLT: Platelets ; Hb : Hemoglobin ; RBC : Red blood cells ; PCT : Procalcitonin ; SAA༚Serum amyloidA protein; IL-1: Interleukin-1; IL-6: Interleukin-6; IL-10: Interleukin-10;CD4་T:CD4་T lymphocytes; CD8་T :CD8་T lymphocytes; TotalT: Totallymphocytes ; ALT: Alanine aminotransferase; AST: Aspartate transaminase; ALP: alkaline phosphatase; GGT: Gamma glutamyl transferase; ALB:Albumin; TB:Total bilirubin; DB: Direct bilirubin; APTT:Activated partial thromboplastin time; PT:Prothrombin time; CK: Creatine kinase; α-HBDB: α-Hydroxybutyrate Dehydrogenase; LDH:Lactatedehydrogenase; BUN: Blood urea nitrogen; Cr:Creatinine; IQR: Inter quartile range |
The patients in severe group had persistent and more severe lymphopenia (0.72 (IQR, 0.5–1.05)) than mild group (1.11 (IQR, 0.74–1.46)); Median platelet counts were significantly lower in severe group (170 (IQR, 135–241)) than mild group (211 (IQR, 163.5–280)). The patients in severe group had more leukocytosis (6.14 (IQR, 4.71–8.68)) than mild group (5.08 (IQR, 3.71–6.08)). Concentrations of procalcitonin, high sensitivity C-reactive protein were significantly higher in severe group than in mild group (0.08 (IQR, 0.04–0.23) vs 0.02(IQR, 0.02–0.05), P < 0.0001), (300 (IQR, 153.03–300) vs 114.65(IQR, 19.41–300), P < 0.0001).
Concentrations of alanine aminotransferase, aspartate aminotransferase, total bilirubin, Direct bilirubin, alkaline phosphatase, and Gamma glutamyl transferase were significantly higher in severe group than in mild group. Albumin concentrations were significantly lower in severe group than in mild group(33.8 (IQR,30.7–36.6) vs 36.5 (IQR,34.25–40.2), P < 0.0001). Concentrations of blood urea nitrogen,creatinine, creatine kinase, α-hydroxybutyrate dehydrogenase and lactate dehydrogenase were markedly higher in severe group than in mild group.
Patients in the severe group more often had significantly lower concentrations of CD4+T lymphocyte, CD8+ T lymphocyte and total T lymphocyte count than did patients in the mild group. concentrations of interleukin 1, interleukin 6 and interleukin 10 were significantly higher in severe group than in mild group. Median prothrombin time was significantly longer in severe group (13.2 (IQR, 12.6–14.3)) than in mild group (12.5 (IQR, 12-13.35)), D-dimer and fibrinogen concentrations were markedly greater in severe group than in mild group.Details of other relevant information were shown in Table 2.
Radiological characteristics
The lung lesions inthe two groups were mostly distributed under the pleura, accompanied by multiple patchy or lumpy ground glass opacities, with or without pulmonary consolidation or white lung. In the severe group, the lung lesions were mainly distributed in two lungs, with multiple ground glass opacities (88.97% vs 78.91%, P = 0.0252), pulmonary consolidation (42.07% vs 19.05%, P < 0.0001) and white lung (46.21% vs 2.04%, P < 0.0001,) more common than in the mild group. See Table 3.
Table 3
Lung imaging and Outcome of COVID-19 between mild and severe groups
Variables | Mild group | Severegroup | Pvalue |
Singlelungdistribution,n (%) | 15 (10.2%) | 0 (0%) | < 0.0001 |
Twolung distribution,n (%) | 131 (89.12%) | 145 (100%) | < 0.0001 |
Subpleural distribution,n (%) | 126 (85.71%) | 127 (87.59%) | 0.7315 |
Bronchovascularbundle distribution,n (%) | 62 (42.18%) | 63 (43.45%) | 0.9059 |
SingleGGO,n (%) | 4 (2.72%) | 0 (0%) | 0.1225 |
MultipleGGO,n (%) | 116 (78.91%) | 129 (88.97%) | 0.0252 |
PatchyGGO,n (%) | 114 (77.55%) | 125 (86.21%) | 0.0682 |
LumpGGO,n (%) | 30 (20.41%) | 26 (17.93%) | 0.6564 |
Consolidation,n (%) | 28 (19.05%) | 61 (42.07%) | < 0.0001 |
Whitelung,n (%) | 3 (2.04%) | 67 (46.21%) | < 0.0001 |
TraditionalChinese medicine, n (%) | 71 (48.3%) | 69 (47.59%) | 0.9074 |
Oxygen therapy,n (%) | 47 (31.97%) | 142 (97.93%) | < 0.0001 |
Noninvasive ventilation,n (%) | 0 (0%) | 112 (77.24%) | < 0.0001 |
Invasive ventilation, n (%) | 0 (0%) | 15 (10.34%) | < 0.0001 |
Firstdailydoseof methylprednisolone mean (sd), mg | 15.92 (24.43) | 89.1 (30.46) | < 0.0001 |
Mortality rate, n (%) | 0(0%) | 51(35.17%) | < 0.0001 |
Cure rate, n (%) | 147(100%) | 94(64.83%) | < 0.0001 |
Abbreviations: GGO༚ground glass opacity |
Treatment and outcome
All patients in the two groups were treated with antiviral, anti bacteria, nutrition, traditional Chinese medicine and symptomatic support. Compared with the mild group, the patients in the severe group received more methylprednisolone, oxygen therapy, noninvasive mechanical ventilation and invasive mechanical ventilation, which was significantly higher than that in the mild group. In 145 severe cases, 96 patients were cured and discharged, accounting for 65.31%, 51 patients died, accounting for 34.69%. For the mild group, no dead patients were found and all of them were cured and discharged. There was statistical significance between this two groups, P < 0.0001. See Table 3.
Analysis of related risk factors
Multivariate analysis revealed thatage, CRP, CD4+ T lymphocyte count, CKand α-HBDB wereindependent risk factors for severity of COVID-19. Multivariable regression showed increasing the risk of exacerbation associated with older age (HR 1.15, 95% CI 1.07–1.24, per five year increment; P < 0.0001), increasing the risk of exacerbation associated with CRP (HR 1.18, 95% CI 1.03–1.34, per 20 mg/L increment; P = 0.0167), increasing the risk of exacerbation associated with CK (HR 1.08, 95% CI 1.00-1.16, per U/L increment; P = 0.0467), increasing the risk of exacerbation associated with α-HBDB (HR 1.15, 95% CI 1.06–1.26, per U/L increment; P = 0.0012) and increasing the risk of exacerbation associated with CD4+ T cell counts (HR 0.74, 95% CI 0.68–0.81, per U/L reduction; P < 0.0001).See Table 4.
Table 4
Exacerbation risk factors ofCOVID-19 in COXmodel using lassoalgorithm
Risk Factors | HR | 95% CI | P value |
Age | 1.15 | (1.07, 1.24) | ༜0.0001 |
CRP | 1.18 | (1.03, 1.34) | 0.0167 |
CD4+ T cell counts | 0.74 | (0.68, 0.81) | ༜0.0001 |
CK | 1.08 | (1.00, 1.16) | 0.0467 |
α-HBDB | 1.15 | (1.06, 1.26) | 0.0012 |
Abbreviations:HR:Hazard ratio; CI: Confidence interval; CRP:C-reactive protein ; CK: Creatine kinase; α-HBDB: α-Hydroxybutyrate Dehydrogenase. |