Table 2.

Multivariate Cox regression of factors associated with COVID-19 nucleic acid viral shedding time.

	Univariate		Multivariate*
	HR (95%CI)	P-value	Adjusted HR (95%CI)	P Value
Female	1.17 (1–1.37)	0.049	1.07 (0.89–1.29)	0.453
Age ≤ 70 yrs	Ref	Ref	Ref	Ref
Age > 70 yrs	0.63 (0.53–0.75)	<0.001	0.78 (0.61–0.99)	0.037
Comorbidities
CKD stage 4–5	0.44 (0.36–0.54)	<0.001	0.61 (0.46–0.8)	<0.001
Metabolic disease	0.66 (0.53–0.81)	<0.001	0.81 (0.64–1.04)	0.098
Heart conditions	0.61 (0.51–0.73)	<0.001	0.76 (0.6–0.97)	0.030
Isolated hypertension	0.77 (0.62–0.95)	0.013	0.81 (0.61–1.06)	0.125
Cerebral vascular disease	0.93 (0.68–1.27)	0.656	–	–
Lung disease	0.75 (0.54–1.04)	0.083	–	–
Cancer	0.85 (0.66–1.1)	0.218	–	–
Acute conditions	0.79 (0.56–1.11)	0.178
Neurodegenerative disease	1.09 (0.73–1.64)	0.669	–	–
Bone fracture	0.66 (0.37–1.17)	0.152	–	–
Autoimmune diseases	0.62 (0.26–1.5)	0.292	–	–
Long-term bedridden	0.62 (0.51–0.76)	<0.001	0.9 (0.68–1.19)	0.452
COVID-19 vaccination
Not fully vaccinated	Ref	Ref	Ref	Ref
Fully vaccinated or booster	1.98 (1.66–2.37)	<0.001	1.4 (1.14–1.72)	0.001
Severe/Critical cases	0.56 (0.42–0.74)	<0.001	0.97 (0.67–1.39)	0.852

*554 participants were enrolled for multivariate regression after removing missing values.

Note: Factors with adjusted HR <1.00 and P-value < 0.05 were considered as risk factors for viral shedding while factors with adjusted HR >1.00 and P-value < 0.05 were considered as protective factors. Smaller or bigger adjusted HR indicates stronger risk or protection, respectively.

Abbreviation: HR: Hazard Ratio; 95%CI: 95% confidence interval; CKD: Chronic Kidney Disease; yrs: years old;