TABLE 2.
Group variables | Variable | HRc | 95%CI | p-value | HRd | 95%CI | p-value | HRe | 95%CI | p-value |
---|---|---|---|---|---|---|---|---|---|---|
Demographic variables | Male | 1.68 | 0.70–4.08 | 0.248 | ||||||
Age (years) a | 1.04 | 1.01–1.07 | 0.015 | 1.05 | 1.02–1.09 | 0.001 | ||||
COVID-19 wave | Second | 1.26 | 0.64–2.50 | 0.503 | ||||||
Smoking habit | Smokers | 2.24 | 0.60–8.34 | 0.231 | ||||||
Ex-smokers | 1.04 | 0.41–2.63 | 0.930 | |||||||
Comorbidities and physical examination | Hypertension | 1.60 | 0.79–3.24 | 0.196 | ||||||
Dyslipidemia | 1.70 | 0.86–3.38 | 0.128 | |||||||
Cardiovascular disease | 1.51 | 0.77–2.98 | 0.230 | |||||||
Diabetes mellitus | 2.26 | 1.09–4.68 | 0.029 | 2.25 | 1.08–4.69 | 0.030 | 2.63 | 1.23–5.64 | 0.013 | |
Previous pulmonar disease | 1.44 | 0.68–3.03 | 0.340 | |||||||
Immunosuppression | 4.85 | 2.15–10.95 | <0.001 | 4.87 | 2.15–11.07 | <0.001 | 3.15 | 1.17–8.51 | 0.024 | |
Confirmed diagnosis by PCR | 0.59 | 0.26–1.33 | 0.204 | |||||||
Pharmacological treatment | Lopinavir/ritonavir | 0.75 | 0.38–1.48 | 0.407 | ||||||
Azytromicine | 0.85 | 0.43–1.69 | 0.640 | |||||||
Anakinra | 0.99 | 0.35–2.83 | 0.993 | |||||||
Methylprednisolone | 0.93 | 0.33–2.66 | 0.899 | |||||||
Ciclosporine | 2.59 | 0.35–19.36 | 0.354 | |||||||
Pulses of methylprednisolone | 0.85 | 0.42–1.72 | 0.644 | |||||||
Colchicine | 1.27 | 0.17–9.35 | 0.814 | |||||||
Hydroxycloroquine | 0.79 | 0.40–1.57 | 0.507 | |||||||
More than one dose of TCZ | 1.03 | 0.46–2.29 | 0.941 | |||||||
Days since symptoms until TCZa | 0.93 | 0.86–1.02 | 0.117 | |||||||
Days since diagnosis until TCZ a | 1.06 | 1.03–1.09 | <0.001 | 1.07 | 1.03–1.10 | <0.001 | 1.05 | 1.00–1.09 | 0.032 | |
Symptoms and signs pre-TCZ | Dry cough | 1.00 | 0.47–2.16 | 0.991 | ||||||
Fatigue | 0.75 | 0.38–1.48 | 0.411 | |||||||
Myalgia | 0.35 | 0.15–0.86 | 0.021 | 0.35 | 0.15–0.86 | 0.021 | ||||
Dyspnea | 0.69 | 0.35–1.38 | 0.294 | |||||||
Headache | 0.70 | 0.25–2.00 | 0.511 | |||||||
Diarrhea | 0.68 | 0.16–2.87 | 0.602 | |||||||
Acute Respiratory distress syndrome | 0.68 | 0.30–1.53 | 0.353 | |||||||
Acute cardiac injury | 3.22 | 0.76–13.64 | 0.113 | |||||||
Thrombosis | 0.88 | 0.12–6.43 | 0.897 | |||||||
Acute renal injury | 1.95 | 0.75–5.08 | 0.172 | |||||||
Scale ERVIa | 1.02 | 0.83–1.25 | 0.858 | |||||||
Hospitalization when TCZ administration | 0.64 | 0.30–1.35 | 0.243 | |||||||
Fever | 0.62 | 0.25–1.53 | 0.301 | |||||||
Laboratory findings pre-TCZ | Total serum proteins (gr/dL) b | 0.53 | 0.31–0.92 | 0.025 | ||||||
Aspartate transaminase (U/L)b | 0.78 | 0.39–1.56 | 0.481 | |||||||
Alanine transaminase (U/L)b | 0.55 | 0.30–1.00 | 0.052 | |||||||
γ-Glutamyl transferase (U/L)b | 0.67 | 0.38–1.18 | 0.161 | |||||||
Procalcitonin (ng/ml)b | 0.97 | 0.74–1.26 | 0.804 | |||||||
Albumin (gr/dL)b | 0.40 | 0.05–3.50 | 0.409 | |||||||
Interleukin-6 (pg/ml)b | 1.08 | 0.79–1.48 | 0.611 | |||||||
Lactate deshydrogenase (U/L)b | 1.87 | 0.55–6.29 | 0.312 | |||||||
C-reactive protein (mg/L)b | 0.93 | 0.66–1.31 | 0.669 | |||||||
Ferritin (ng/ml)b | 1.24 | 0.82–1.88 | 0.302 | |||||||
Leukocyte count (/μL)b | 0.69 | 0.31–1.54 | 0.368 | |||||||
Neutrophil count (/μL)b | 0.69 | 0.32–1.48 | 0.343 | |||||||
Lymphocyte count (/μL)b | 0.88 | 0.47–1.65 | 0.695 | |||||||
Platelet count (/μL) b | 0.20 | 0.10–0.40 | <0.001 | 0.20 | 0.10–0.41 | <0.001 | 0.27 | 0.11–0.69 | 0.006 | |
Fibrinogen (mg/dl)b | 1.00 | 1.00–1.00 | 0.440 | |||||||
Troponin I (pg/ml) b | 1.35 | 1.08–1.69 | 0.007 | |||||||
D-dimer (mg/L)b | 1.15 | 0.86–1.52 | 0.342 | |||||||
PaO2/FiO2 (mmHg)b | 0.79 | 0.30–2.25 | 0.663 | |||||||
Temperature°C a | 0.39 | 0.21–0.76 | 0.005 |
PCR: polymerase Chain Reaction; Scale ERVI: X-ray scale for assessment of hospital admission; TCZ: Tocilizumab; HR: hazard ratio; CI: confidence interval. For dichotomous variables, the reference category was “no” except hospitalization when TCZ administration that it was “general ward” (comparison ICU) and confirmed diagnosis-PCR that it was “suspicious diagnosis with negative PCR” (comparison confirmed positive PCR result). For smoking habit the reference was “never smoker”. Highlighted in bold if p < 0.05.
aHazard ratios are expressed per unit increase in the variable.
bLog-transformed quantitative variables.
cObtained with Cox’s univariate proportional hazard regression models.
dObtained with stepwise regression model within groups of variables, including variables with p-value <0.2 in univariate analysis, except total serum proteins (N = 99), troponin I (N = 80) and temperature (N = 60) which were excluded from multivariate models because of presenting >10% of missing values.
eObtained with stepwise regression including variables retained in models by group.