Table 2.
Multivariate Analysis
| Generalized Linear Logistic Mixed Model | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Blood | LRT | URT | |||||||
| Parameter | Estimator | SE | P Value | Estimator | SE | P Value | Estimator | SE | P Value |
| Intercept | 8.82 | 1.88 | <.0001 | 6.84 | 1.81 | .0002 | 10.63 | 2.27 | <.0001 |
| Age, y | –0.06 | 0.02 | <.0001 | –0.07 | 0.01 | <.0001 | –0.15 | 0.02 | <.0001 |
| Sex (ref: Male) | 0.78 | 0.32 | .01 | 1.01 | 0.21 | <.0001 | 1.15 | 0.40 | .004 |
| BMI, kg/m2 | 0.11 | 0.02 | <.0001 | 0.10 | 0.01 | <.0001 | 0.25 | 0.06 | <.0001 |
| Charlson comorbidity index (1–13) | –0.40 | 0.10 | .0001 | –0.22 | 0.05 | <.0001 | –0.07 | 0.09 | .45 |
| SARS-CoV-2 RNA load (unit: 1 log10 level), copies/mL | –1.49 | 0.31 | <.0001 | –0.29 | 0.07 | <.0001 | –0.64 | 0.14 | <.0001 |
| Clinically diagnosed ARDS | –2.17 | 1.75 | .21 | –0.57 | 0.97 | .56 | 0.85 | 0.64 | .18 |
| Mechanical ventilation | 0.74 | 1.84 | .69 | –1.12 | 1.88 | .55 | –3.10 | 0.82 | .0001 |
| ECMO | –2.87 | 0.49 | <.0001 | –3.41 | 0.35 | <.0001 | –5.77 | 1.15 | <.0001 |
| Viremia (ref: none) | a | a | a | –1.52 | 0.25 | <.0001 | –1.90 | 0.45 | <.0001 |
The patients’ 90-day survival status served as the dependent variable. Multivariate analysis (generalized linear logistic mixed model) reveals blood and LRT RNA levels as predictors of adverse outcomes. The patient (correlation structure: compound symmetry) and time (correlation structure: first order autoregression) were set as random factors to account for repeated measurements. Firth approximation was used to improve the model’s fitness. Model estimators for the GLMM (blood) were AIC, 393.28; c-c, 0.86. For the GLMM (LRT), they were AIC, 923.81; c-c, 0.84. For GLMM (LRT), they were AIC, 337.44; c-c, 0.92.
Abbreviations: AIC, Akaike Information Criterion; ARDS, acute respiratory distress syndrome; BMI, body mass index; ECMO, extracorporeal membrane oxygenation; GLMM, generalized linear mixed model; LRT, lower respiratory tract; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; URT, upper respiratory tract.
Not applicable.