Table 3.

Risk factors for coinfection in patients with acute viral infection.

Model A Baseline Characteristics				Model B Clinical Presentation				Model C Biomarkers (Continuous)				Model D Biomarkers (Categorical †)
Variable	OR	95% CI	p-Value	Variable	OR	95% CI	p-Value	Variable	OR	95% CI	p-Value		OR	95% CI	p-Value
Heart failure	1.929	0.789–4.719	0.150		1.956	0.777–4.926	0.155		2.293	0.845–6.225	0.103		2.357	0.918–6.048	0.075
Nephropathy	3.649	1.422–9.367	0.007		3.086	1.161–8.208	0.024		2.792	0.959–8.127	0.060		3.193	1.098–9.291	0.033
COVID vaccination	0.160	0.055–0.471	<0.001		0.163	0.054–0.489	0.001		0.175	0.055–0.557	0.003		0.155	0.047–0.504	0.002
Age (cont.)	1.016	0.993–1.040	0.175		1.011	0.987–1.035	0.386		1.012	0.986–1.038	0.377	Age ≥ 70 years	0.943	0.439–2.025	0.880
				Bilateral pneumonia	1.321	0.572–3.047	0.907		1.140	0.444–2.923	0.785		1.239	0.497–3.089	0.646
				COVID infection	2.390	1.165–4.902	0.017		2.356	1.080–5.140	0.031		2.795	1.292–6.046	0.009
								CRP	1.000	0.996–1.004	0.983	CRP	1.002	0.997–1.006	0.460
								SBP	0.980	0.967–0.995	0.007	SBP ≤ 130 mmHg	3.588	1.776–7.251	<0.001
								WBC	1.000	1.000–1.000	0.075	WBC ≥ 8000 cells/µL	1.668	0.799–3.480	0.173

Logistic regression analysis for the prediction of risk factors for the occurrence of coinfection in patients with a positive viral swab. Models depending on the available clinical information and biomarkers are shown. Significant variables are in bold. WBCs: white blood cells; CRP = C-reactive protein; SBP = systolic blood pressure. † C-reactive protein was left as a continuous variable as no physiologically or pathologically sound threshold was identified to be considered as a risk factor to differentiate the presence of coinfection. Significant risk factors are highlighted in bold.