Table 3.

Kaplan-Meier method and multivariate Cox regression analysis to identify risk factors of prolonged viral shedding time

Variables	Univariate analysis		Multivariate analysis
	χ2	p Value	p Value	Hazard ratio	95% Confidence interval
Age (≥ 70 years)	1.356	0.244
Gender (Male)	0.177	0.674
Treatment for B-cell lymphoma
Rituximab	0.003	0.954
Obinutuzumab	1.829	0.176
Bendamustine	15.422	< 0.001	0.015	3.056	1.238–7.541
Polatuzumab vedotin	0.324	0.570
Within 1 year of last treatment for B-cell lymphoma	5.410	0.020	0.021	2.373	1.141–4.932
Multiple treatment lines	4.150	0.042	0.029	2.601	1.102–6.138
Subtype of malignant lymphomas
Follicular lymphoma	1.575	0.209
Diffuse large B-cell lymphoma	7.750	0.005
Less than 2 vaccinations	0.006	0.939
Negative spike-specific antibody (seronegative)	0.279	0.597
Absolute lymphocyte count ≦482 cells/mL	6.047	0.014	0.909	0.954	0.427–2.133
Treatment for COVID-19
Remdesivir	8.204	0.004	0.372	0.708	0.332–1.511
Molnupiravir	3.769	0.052
Nirmatrelvir/ritonavir	1.683	0.195
Ensitrelvir	0.055	0.814
First treated with combination therapy	0.427	0.513
Corticosteroid	7.099	0.008	0.093	1.898	0.899–4.008
Baricitinib	2.279	0.131
Severe or critical COVID-19	7.312	0.007
CT findings suggestive of COVID-19 pneumonia	3.326	0.068