Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study

Figures & data

Table 1 Enrolled Outpatients According to Sex and Age Stratification

		Group SC	Group QP	p
N		76	76
Sex: Male/Female		46/30	42/34	n. s.
Age (years)	71–80	2	1	n. s.
	61–70	6	7	n. s.
	51–60	18	17	n. s.
	41–50	17	18	n. s.
	31–40	14	13	n. s.
	21–30	14	16	n. s.
	18–20	5	4	n. s.

Abbreviations: SC, standard care; QP, formulated quercetin (+standard care); n. s., not significant.

Table 2 Clinical Outcomes in the Two Studied Groups

	Group SC	Group QP	p^a	p^b	p^c
Patients hospitalized	22 (28.9%)	7 (9.2%)	0.0016	0.0020
Days of hospitalization*	6.77 ± 3.08	1.57 ± 0.53			0.0001
Hospitalization frequencies			0.0001	0.0037
1 day	0	3
2 days	1	4
3 days	2	0
4 days	3	0
5 days	1	0
6 days	3	0
7 days	4	0
8 days	3	0
9 days	2	0
10 days	2	0
16 days	1	0
Patients needed oxygen	15 (19.7%)	1 (1.3%)	0.0100	0.0125
Patients in ICU	8 (10.5%)	0	0.0211	0.0608
Deaths	3 (3.9%)	0	0.04	0.0802

Notes: *Expressed as mean ± standard deviation; p^a: likelihood ratio; p^b: Pearson; p^c: t test and Wilcoxon/Kruskal–Wallis tests.

Abbreviations: SC, standard care; QP, formulated quercetin (+standard care); ICU, intensive care unit.

Table 3 Number of Patients with or without Comorbidities at the Enrolment

	Group SC	Group QP	p^a	p^b
With comorbidities	45 (59.2%)	29 (38.2%)	0.0092	0.0094
Frequency of comorbidities*
0	31 (40.8%)	47 (62.8%)
1	23 (30.3%)	16 (22.2%)
>1	22 (28.9%)	13 (15.0%)

Notes: p^a: likelihood ratio; p^b: Pearson; *Tuberculosis; asthma; allergy; type 2 diabetes; type 1 diabetes; gestational diabetes; hypertension; hypercholesterolemia; heart disease; chronic lung disease; thalassemia; polycystic ovary syndrome.

Abbreviations: SC, standard care; QP, formulated quercetin (+standard care).

Table 4 Statistical Relationship Between Comorbidities and Hospitalization

	Hospitalized	Not Hospitalized	p^a	p^b
With comorbidities	18 (62.1%)	56 (45.5%)	0.1078	0.1089
Without comorbidities	11 (37.9%)	67 (54.5%)

Notes: p^a: likelihood ratio; p^b: Pearson.

Abbreviations: SC, standard care; QP, formulated quercetin (+standard care).

Table 5 Clinical Outcomes in the Two Studied Groups Only Considering Patients with No Comorbidities at the Enrolment

	Group SC	Group QP	p^a	p^b	p^c
Patients	31	47
Patients hospitalized	7 (22.6%)	4 (8.5%)	0.0840	0.0806
Days of hospitalization*	5.14 ± 2.79	1.25 ± 0.50			0.0097
Hospitalization frequencies			0.0410	0.1147
1 day	0	3
2 days	1	4
3 days	2	0
4 days	3	0
7 days	4	0
8 days	3	0
9 days	2	0
Patients needed oxygen	4 (12.9%)	0	0.0055	0.0115
Patients in ICU	2 (6.5%)	0	0.0521	0.0777
Deaths	2 (6.5%)	0	0.0521	0.0777

Notes: *Expressed as mean ± standard deviation; p^a: likelihood ratio; p^b: Pearson; p^c: t test and Wilcoxon/Kruskal–Wallis tests.

Abbreviations: SC, standard care; QP, formulated quercetin (+standard care); ICU, intensive care unit.