Figure 1
Univariate logistic analysis of the severity and mortality of COVID-19
| Variable | Severity | Mortality | ||||
|---|---|---|---|---|---|---|
| OR | Lower–upper | P | OR | Lower–upper | P | |
| Age | 1.03 | 1.02–1.04 | <0.001*** | 1.04 | 1.01–1.07 | 0.003** |
| Sex | 1.02 | 0.63–1.65 | 0.942 | 0.79 | 0.31–2.06 | 0.63 |
| Comorbidity | 2.47 | 1.51–4.03 | <0.001*** | 4.25 | 1.36–13.26 | 0.013* |
| Time from illness onset to first admission [median (IQR)] | 1.07 | 1.00–1.15 | 0.48 | 1.12 | 1.02–1.23 | 0.013* |
| Time from admission to discharge/death [median (IQR)] | 1.06 | 0.99–1.14 | 0.06 | 1.13 | 1.02–1.24 | 0.012* |
| Albumin | 1.04 | 0.66–1.64 | 0.86 | 0.69 | 0.28–1.70 | 0.42 |
| ALK-p | 0.998 | 0.996–1.000 | 0.053 | 0.998 | 0.99–1.00 | 0.38 |
| Direct bilirubin | 0.92 | 0.57–1.50 | 0.74 | 1.11 | 0.55–2.27 | 0.77 |
| Total bilirubin | 1.08 | 0.77–1.52 | 0.66 | 1.20 | 0.82–1.78 | 0.35 |
| Calcium | 1.06 | 0.71–1.59 | 0.77 | 1.24 | 0.11–0.51 | <0.001*** |
| Corrected calcium | 0.97 | 0.63–1.49 | 0.89 | 1.42 | 0.21–0.81 | 0.01* |
| CRP | 1.01 | 0.98–1.04 | 0.58 | 0.98 | 0.88–1.09 | 0.64 |
| ESR | 1.01 | 0.996–1.016 | 0.27 | 1.00 | 0.98–1.02 | 0.80 |
| Hematocrit | 1.06 | 1.02–1.10 | 0.004** | 1.03 | 0.96–1.12 | 0.40 |
| Hemoglobin | 1.12 | 1.01–1.24 | 0.030* | 1.09 | 0.89–1.33 | 0.40 |
| LDH | 1.00 | 1.000–1.003 | 0.016* | 1.00 | 1.000–1.001 | 0.024* |
| Lymphocyte count (/μL) | 0.81 | 0.64–1.03 | 0.090 | 1.08 | 0.74–1.57 | 0.69 |
| Lymphocyte percentage | 0.97 | 0.95–0.99 | 0.004** | 0.99 | 0.94–1.03 | 0.50 |
| Mean corpuscular Hb concentration | 0.95 | 0.86–1.05 | 0.30 | 0.95 | 0.79–1.14 | 0.55 |
| Mean cell hemoglobin | 0.99 | 0.92–1.06 | 0.73 | 1.07 | 0.92–1.25 | 0.38 |
| Mean cell volume | 1.01 | 0.98–1.04 | 0.53 | 1.05 | 0.98–1.12 | 0.19 |
| Mean platelet volume | 0.97 | 0.91–1.04 | 0.39 | 1.01 | 0.94–1.08 | 0.76 |
| Mixed cell count | 0.84 | 0.58–1.23 | 0.38 | 0.79 | 0.24–2.55 | 0.69 |
| Mixed cell percentage | 0.95 | 0.90–1.00 | 0.062 | 0.89 | 0.77–1.03 | 0.12 |
| Neutrophil count | 1.06 | 1.01–1.13 | 0.03* | 1.04 | 0.95–1.13 | 0.42 |
| Neutrophil percentage | 1.01 | 0.996–1.021 | 0.17 | 1.01 | 0.98–1.03 | 0.61 |
| P-LCR | 0.996 | 0.97–1.02 | 0.75 | 1.04 | 0.99–1.10 | 0.11 |
| Platelet distribution width | 1.00 | 0.93–1.07 | >0.99 | 1.12 | 0.95–1.32 | 0.18 |
| Phosphorus | 0.82 | 0.66–1.01 | 0.063 | 0.36 | 0.19–0.69 | 0.002** |
| Platelet count (×103/μL) | 1 | 1–1 | 0.96 | 1.00 | 1.000–1.000 | 0.010* |
| Potassium | 0.97 | 0.57–1.65 | 0.91 | 0.30 | 0.09–0.97 | 0.045* |
| RBC count | 1.39 | 1.03–1.88 | 0.033* | 0.62 | 0.39–1.00 | 0.049* |
| RDW–CV | 1.20 | 1.06–1.37 | 0.005** | 1.04 | 0.84–1.29 | 0.71 |
| RDW–SD | 1.06 | 1.01–1.10 | 0.009** | 1.03 | 0.97–1.10 | 0.34 |
| AST | 1.01 | 1.00–1.01 | 0.074 | 1.00 | 1.00–1.01 | 0.14 |
| Alanine transaminase | 1.01 | 0.999–1.011 | 0.14 | 1.00 | 0.998–1.003 | 0.81 |
| Sodium | 0.94 | 0.891–0.998 | 0.043* | 0.90 | 0.80–1.01 | 0.07 |
| White blood cell count (/μL) | 1.00 | 1.00–1.00 | 0.59 | 1.00 | 1.00–1.00 | 0.89 |
Logistic regression of risk factors related to severity of COVID-19
| Variable | B | SE | OR | 95% CI | Wald statistic | P |
|---|---|---|---|---|---|---|
| Age | 0.23 | 0.007 | 1.02 | 1.01–1.04 | 10.5 | 0.001** |
| Hematocrit | 0.076 | 0.025 | 1.08 | 1.03–1.13 | 9.42 | 0.002** |
| RDW-CV | 0.162 | 0.073 | 1.18 | 1.02–1.36 | 4.95 | 0.02* |
| Comorbidity | 0.619 | 0.303 | 1.86 | 1.03–3.36 | 4.19 | 0.04* |
Demographic data and baseline characteristics at admission of patients infected with COVID-19 who survived and those who did not
| Variable | All patients | Moderate | Severe | P | Survived | Did not survive | P |
|---|---|---|---|---|---|---|---|
| Age (range) years | 53 (36, 71) | 43 (29, 67) | 61 (46, 74) | <0.001 | 52 (35, 70) | 73 (60, 79) | 0.001 |
| 0–14 years | 18 | 15 | 3 | 18 | 0 | ||
| 15–49 years | 105 | 63 | 42 | 105 | 0 | ||
| 50–64 years | 56 | 26 | 30 | 51 | 5 | ||
| ≥65 years | 107 | 30 | 77 | 94 | 13 | ||
| Female/male | 128/158 | 61/73 | 67/85 | 0.94 | 120/148 | 8/10 | 0.37 |
| Fever on admission | 155 (54.1) | 75 (56) | 80 (53) | 0.59 | 145 (54) | 10 (56) | 0.85 |
| Myalgia or arthralgia | 76 (26.5) | 36 (27) | 40 (26) | 0.89 | 70 (26) | 6 (33) | 0.60 |
| Cough | 177 (61.9) | 87 (65) | 90 (59) | 0.53 | 154 (57) | 14 (78) | 0.21 |
| Dyspnea | 144 (50.3) | 70 (52) | 74 (48) | 0.41 | 133 (50) | 11 (61) | 0.45 |
| Confusion | 31 (10.8) | 17 (13) | 14 (9) | 0.33 | 25 (9) | 6 (33) | 0.09 |
| Seizure | 1 (0.4) | 1 (1) | 0 (0) | 0.28 | 0 | 1 (6) | 0.69 |
| Headache | 134 (46.8) | 69 (52) | 67 (44) | 0.35 | 121 (45) | 13 (72) | 0.27 |
| Chest pain | 41 (14.3) | 19 (14) | 22 (15) | 0.96 | 36 (13) | 5 (28) | 0.27 |
| Abdominal pain | 19 (6.6) | 11 (8) | 8 (5) | 0.31 | 18 (7) | 1 (6) | 0.28 |
| Nausea | 32 (11.1) | 14 (10) | 18 (12) | 0.72 | 31 (12) | 1 (6) | 0.19 |
| Vomiting | 23 (8.04) | 13 (10) | 10 (7) | 0.32 | 22 (8) | 1 (6) | 0.20 |
| Diarrhea | 5 (1.7) | 3 (2) | 2 (1) | 0.64 | 4 (2) | 1 (6) | 0.20 |
| Comorbidity | 135 (47.2) | 48 (36) | 87 (57) | 0.006 | 121 (45) | 14 (78) | 0.007 |
| Cancer | 5 (1.7) | 2)2) | 3 (2) | 0.76 | 4 (2) | 1 (6) | 0.25 |
| Liver | 2 (0.7) | 2 (2) | 0 (0) | 0.06 | 2 (1) | 0 | 0.69 |
| Diabetes mellitus | 43 (15.0) | 12 (9) | 31 (20) | 0.02 | 38 (14) | 5/15 (28) | 0.19 |
| Hematology | 4 (1.4) | 2 (2) | 2 (1) | 0.48 | 4 (2) | 0 | 0.58 |
| Pregnancy | 7 (2.4) | 7 (5) | 0 (0) | 0.007 | 7/259 (3) | 0 | 0.026 |
| Heart disease | 51 (17.8) | 17 (13) | 34 (22) | 0.15 | 45 (17) | 6 (33) | 0.14 |
| Hypertension | 80 (28.0) | 17 (13) | 63 (42) | 0.014 | 75 (28) | 5 (28) | 0.86 |
| Asthma | 9 (3.1) | 5 (4) | 4 (3) | 0.058 | 9/257 (3) | 0 | 0.40 |
| COPD | 38 (13.3) | 9 (7) | 29 (19) | 0.006 | 35 (13) | 3 (17) | 0.80 |
| Neurology | 16 (5.6) | 7 (5) | 9 (6) | 0.8 | 14 (5) | 2 (11) | 0.37 |
| Other | 40 (14.0) | 15 (11) | 25 (17) | 0.26 | 39 (15) | 1 (6) | 0.23 |
| Time from illness onset to first admission | 4 (3, 7) | 4 (2, 6) | 4 (3, 7) | 0.023 | 4 (3, 6) | 7 (3, 10.5) | 0.045 |
| Time from admission to discharge/death | 15 (14, 19) | 15 (13, 18) | 15 (14, 19) | 0.047 | 15 (14, 18) | 18 (14, 21.5) | 0.031 |
| First oxygen mode | |||||||
| No oxygen inhalation | 144 (50.3) | 91 (68) | 0 (0) | <0.001 | 143 (53) | 1 (10) | <0.001 |
| Nasal catheter for oxygen | 117 (40.9) | 43 (32) | 130 (86) | 113 (42) | 4 (22) | ||
| Face mask oxygen inhalation | 16 (5.6) | 0 | 17 (11) | 12 (4) | 4 (22) | ||
| High-flow oxygen | 5 (1.7) | 0 | 5 (3) | 0 | 5 (28) | ||
| Noninvasive ventilation | 4 (1.4) | 0 | 0 | 4 (22) | |||
| Tracheal intubation | 0 | 0 | 0 | 0 | |||
Area under the ROC curve and optimal threshold of each COVID-19-related variable
| Variables | AUC | 95% CI | P | Optimal threshold | Sensitivity | Specificity |
|---|---|---|---|---|---|---|
| Calcium | 0.759 | 0.69–0.82 | 0.001** | ≤6.4 | 64.7 | 59.1 |
| LDH | 0.731 | 0.64–0.81 | 0.039* | >4,622 | 55.6 | 92.7 |
| Phosphorus | 0.725 | 0.66–0.79 | <0.001** | ≤1.5 | 76.5 | 69.2 |
| Bilirubin Total | 0.689 | 0.61–0.76 | 0.003** | >4.8 | 66.7 | 69.4 |
| Total CRP | 0.679 | 0.62–0.74 | 0.013* | >90 | 53.3 | 83.1 |
| RDW SD | 0.624 | 0.56–0.68 | 0.035* | >79.3 | 88.9 | 38.2 |
Logistic regression of risk factors related to mortality of patients with COVID-19
| Variable | B | SE | OR | 95% CI | Wald statistic | P |
|---|---|---|---|---|---|---|
| Calcium | −1.453 | 0.466 | 0.20 | 0.09–0.58 | 9.726 | 0.002** |
| Phosphorus | −0.662 | 0.346 | 0.50 | 0.26–1.02 | 3.651 | 0.04* |
| P-LCR | 0.069 | 0.035 | 1.10 | 1.00–1.15 | 994 | 0.04* |
| Age | 0.034 | 0.017 | 1.00 | 1.00–1.07 | 4.039 | 0.03* |
Laboratory findings at admission of patients infected with SARS-CoV-2
| Variable, median (IQR) | Total | Disease severity | Mortality | ||||
|---|---|---|---|---|---|---|---|
| Admission data | Moderate | Severe | P | Survived | Did not survive | P | |
| Albumin (g/dL) | 3.2 (2.9, 3.5) | 3.2 (2.83, 3.5) | 3.2 (2.8, 3.5) | 0.57 | 3.2 (2.9, 3.5) | 3.0 (2.75, 3.5) | 0.38 |
| ALK-p (IU/L) | 180 (142, 254) | 172 (144, 276) | 188 (138, 246) | 0.90 | 180 (139, 262) | 193 (144, 239) | 0.90 |
| Direct bilirubin (mg/dL) | 0.2 (0.1, 0.4) | 0.2 (0.1, 0.4) | 0.2 (0.1, 0.4) | 0.78 | 0.2 (0.1, 0.4) | 0.4 (0.2, 0.6) | 0.01* |
| Total bilirubin (mg/dL) | 0.6 (0.4, 1.0) | 0.5 (0.4, 0.82) | 0.6 (0.4, 1.12) | 0.29 | 0.5 (0.4, 0.9) | 0.9 (0.65, 1.4) | 0.01* |
| Calcium (mg/dL) | 8.3 (8.0, 8.7) | 8.3 (8.0, 8.7) | 8.3 (8.0, 8.7) | 0.56 | 8.4 (8.0, 8.7) | 8.0 (7.2, 8.2) | <0.001*** |
| Corrected calcium (mg/dL) | 8.96 (8.56, 9.28) | 8.94 (8.44, 9.26) | 8.94 (8.57, 9.35) | 0.56 | 8.98 (8.62, 9.34) | 8.68 (7.91, 9.02) | 0.01* |
| CRP (mg/L) | 10.0 (4.0, 15.5) | 8.0 (4.0, 16.0) | 10.0 (3.5, 15.0) | 0.90 | 9.5 (4.0, 16.0) | 10 (2.0, 13.0) | 0.68 |
| ESR (mm/h) | 30 (13, 51) | 26 (13, 50) | 33 (14.5, 53) | 0.30 | 29 (13, 51) | 32 (18.8, 53.3) | 0.64 |
| Hematocrit (%) | 40.0 (36.1, 43.6) | 39.8 (36.1, 42.8) | 41.6 (36.4, 44.6) | 0.027* | 40.0 (36.1, 43.3) | 41.1 (36.0, 44.9) | 0.53 |
| Hemoglobin (g/dL) | 13.8 (11.8, 15.2) | 13.4 (12.0, 14.9) | 14.0 (11.9, 15.4) | 0.093 | 13.8 (11.9, 15.1) | 14.5 (11.4, 16.3) | 0.54 |
| LDH (U/L) | 568 (411, 839) | 466 (398, 667) | 656 (456, 919) | 0.006** | 559 (400, 778) | 1,187 (567, 1,534) | 0.022* |
| Lymphocyte count (×103/μL) | 1.3 (0.9, 1.9) | 1.4 (0.9, 2.1) | 1.3 (0.95, 1.8) | 0.34 | 1.4 (0.97, 1.9) | 1.00 (0.4, 2.02) | 0.13 |
| Lymphocytes (%) | 18.9 (12, 28.0) | 20.5 (13.2, 31.7) | 16.9 (11.3, 25.3) | 0.01* | 18.9 (12.0, 28.1) | 18.7 (12.1, 22.4) | 0.5 |
| Mean corpuscular hemoglobin concentration (g/dL) | 34.2 (32.4, 35.3) | 34.6 (32.7, 35.6) | 33.9 (32.3, 35.0) | 0.07 | 34.2 (32.5, 35.3) | 33.5 (32.05, 35.6) | 0.63 |
| Mean cell hemoglobin (pg) (mean ± SD) | 30.11 ± 3.44 | 30.18 ± 3.03 | 30.04 ± 3.77 | 0.73 | 30.06 ± 3.35 | 30.79 ± 4.67 | 0.38 |
| Mean corpuscular volume (fL) | 89.9 (85.6, 93.5) | 89.3 (85.6, 92.9) | 90.7 (85.8, 94.6) | 0.11 | 89.9 (85.4, 93.4) | 91.0 (87.8, 97.5) | 0.11 |
| Mean platelet volume (fL) | 9.2 (8.6, 10.1) | 9.3 (8.7, 10.1) | 9.1 (8.5, 10.1) | 0.40 | 9.2 (8.6, 10.0) | 9.3 (8.67, 10.9) | 0.34 |
| Mixed cell count (×103/μL) | 0.4 (0.12, 0.7) | 0.4 (0.2, 0.7) | 0.4 (0.1, 0.6) | 0.53 | 0.4 (0.19, 0.7) | 0.2 (0, 0.65) | 0.32 |
| Mixed cell (%) | 5.4 (3.0, 8.5) | 6.0 (3.3, 9.2) | 5.0 (3.0, 8.0) | 0.07 | 5.4 (3.1, 8.6) | 4.7 (2.2, 8.2) | 0.13 |
| Neutrophil count (×103/μL) | 4.5 (2.6, 7.6) | 4.1 (3.0, 6.1) | 4.7 (2.4, 8.3) | 0.12 | 4.5 (2.6, 7.4) | 5.2 (3.1, 8.7) | 0.39 |
| Neutrophil (%) | 73.7 (62.0, 83.0) | 71.3 (59.1, 80.9) | 76.05 (63.6, 83.7) | 0.02* | 73.2 (61.6, 83.1) | 76.1 (71.4, 81.6) | 0.39 |
| Potassium (mmol/L) | 4.0 (3.8, 4.3) | 4.0 (3.8, 4.3) | 4.0 (3.7, 4.3) | 0.80 | 4.0 (3.8, 4.3) | 3.9 (3.4, 4.0) | 0.29 |
| P-LCR | 21.6 (16.5, 27.8) | 71.3 (59.1, 80.9) | 21.3 (16.2, 27.5) | 0.53 | 21.6 (16.5, 27.7) | 22.2 (18.2, 33.2) | 0.23 |
| Platelet distribution width (%) | 11.2 (9.9, 12.9) | 11.3 (9.9, 12.9) | 11.1 (9.8, 12.85) | 0.74 | 11.2 (9.9, 12.8) | 11.5 (9.9, 13.3) | 0.71 |
| Phosphorus (mg/dL) | 3.3 (2.6, 4.1) | 3.3 (2.8, 4.3) | 3.3 (2.5, 4.0) | 0.25 | 3.4 (2.7, 4.2) | 2.7 (2.1, 3.2) | 0.002** |
| Platelet count (×102/μL) | 1,820 (1,405, 2,435) | 1,900 (1,480, 2,515) | 1,790 (1,350, 2,410) | 0.21 | 1,845 (1,410, 2,417) | 1,490 (1,360, 4,875) | 0.90 |
| RBC count (×106/μL) (mean ± SD) | 4.39 ± 0.84 | 4.27 ± 0.82 | 4.49 ± 0.85 | 0.029* | 4.41 ± 0.81 | 4.00 ± 1.15 | 0.047* |
| RDW – CV (%) | 13.7 (13.1, 15.0) | 13.6 (12.9, 14.4) | 13.9 (13.3, 15.4) | 0.007** | 13.7 (13.2, 14.9) | 13.9 (13.0, 15.9) | 0.64 |
| RDW – SD (fL) | 47.3 (44.2, 50.6) | 46.4 (43.3, 49.3) | 48.3 (45.1, 52.3) | <0.001* | 46.9 (44.0, 50.3) | 49.2 (46.4, 51.9) | 0.07 |
| AST (U/L) | 26 (18, 50) | 24 (18, 47) | 28 (19, 57) | 0.23 | 26 (18, 47) | 41 (20, 147) | 0.12 |
| Alanine transaminase (U/L) | 25 (12, 47) | 24 (13, 44) | 26 (12, 52) | 0.27 | 24 (12, 46) | 29 (20, 69) | 0.28 |
| Sodium (mEq/L) | 137 (135, 140) | 138 (136, 140) | 136 (134, 139) | 0.008** | 137 (135, 140) | 135 (133, 138) | 0.05 |
| White blood cell count (/μL) | 7,200 (5,400, 10,525) | 7,050 (5,225, 9,650) | 7,300 (5,400,10,675) | 0.28 | 7,200 (5,400, 10,500) | 7,600 (4,375, 11,475) | 0.90 |