Age and Sex Differences Among Mildly Symptomatic and Asymptomatic Patients with Omicron Infection in 2022 in Shanghai, China

Figures & data

Table 1 The Demographic Features of Patients with COVID-19 in a Hospital in Shanghai, China

Variables	Total Patients (n=325)	Patients by Sex		t/χ^2	P
		Male (n=191)	Female (n=134)
Age (years)^†, mean (SD)	47.2 (16.8)	45.2 (16.9)	50.1 (16.4)	−2.61	0.001
Age (years)^†, median (IQR)	48.0 (32.5–61.0)	45.0 (31.0–57.0)	52.0 (38.0–64.0)	−2.84	0.004
Age group (years)^†, n (%)				10.07	0.006
<45	146 (44.9)	95 (49.7)	51 (38.1)
45–59	86 (26.5)	54 (28.3)	32 (23.9)
≥60	93 (28.6)	42 (22.0)	51 (38.1)
Month of hospital admission, n (%)				1.71	0.191
March	261 (80.3)	158 (82.7)	103 (76.9)
April	64 (19.7)	33 (17.3)	31 (23.1)
Days of hospitalization, mean (SD)	13.6 (4.5)	13.4 (4.3)	13.9 (4.8)	−0.99	0.325
Days of hospitalization, n (%)				2.86	0.091
≤15 days	230 (70.8)	142 (74.3)	88 (65.7)
>15 days	95 (29.2)	49 (25.7)	46 (34.3)
Censored after hospital discharge, n (%)				0.01	0.93
Yes	93 (28.6)	55 (28.8)	38 (28.4)
No	232 (71.4)	136 (71.2)	96 (71.6)

Note: ^†The differences between males and females were statistically significant (P<0.05).

Abbreviations: SD, standard deviation; IQR, interquartile range.

Table 2 The Virus Nucleic Acid Detection (NAD) Tests for COVID-19 Patients in a Hospital in Shanghai, China

Variables	Total Patients (n=325)	Patients by Sex		t/χ^2	P
		Male (n=191)	Female (n=134)
Times of NAD test^†, mean (SD)	4.3 (2.2)	4.1 (2.1)	4.7 (2.4)	−2.44	0.015
NAD test times^†, n (%)				5.39	0.021
≤5 times	238 (73.2)	149 (78.0)	89 (66.4)
>5 times	87 (26.8)	42 (22.0)	45 (33.6)
Duration for 1st NAD test and hospitalization, median (IQR)	3.0 (2.0–6.0)	5.0 (2.0–7.0)	3.0 (2.0–6.0)	3.79	0.052
Ct value of virus NAD test each time, median (IQR)
Time 1 (n=325)^†	28.4 (23.2–35.8)	30.0 (24.3–36.6)	27.3 (21.5–34.3)	7.01	0.008
Time 2 (n=325)^†	31.9 (23.8–37.2)	33.1 (26.2–37.9)	29.9 (21.8–35.7)	9.70	0.002
Time 3 (n=245)	33.3 (26.9–37.7)	33.7 (28.7–37.9)	31.3 (25.6–37.2)	2.69	0.101
Time 4 (n=170)	36.1 (31.0–38.7)	36.4 (32.9–39.3)	35.7 (30.0–38.1)	1.96	0.162
Time 5 (n=133)	37.5 (34.6–40.0)	37.7 (34.5–40.0)	37.2 (34.9–39.4)	0.61	0.435
Time 6 (n=87)	37.2 (35.6–40.0)	37.2 (36.1–39.2)	37.5 (35.3–40.0)	0.02	0.898
Time 7 (n=52)	37.3 (36.2–39.4)	38.1 (36.2–38.9)	37.1 (36.1–38.7)	1.19	0.275
Time 8 (n=26)	36.6 (35.1–38.9)	36.1 (34.8–38.9)	36.8 (35.5–38.4)	0.29	0.584
Time 9 (n=17)	37.3 (36.1–38.8)	38.3 (34.7–39.6)	36.9 (36.1–38.3)	0.73	0.393
Time 10 (n=14)	37.9 (36.4–40.0)	37.3 (33.8–39.9)	39.5 (37.2–40.0)	2.25	0.133
Time 11 (n=8)	37.2 (36.1–39.4)	37.1 (35.4–40.0)	37.4 (36.7–38.8)	0.03	0.881
Duration between first and last NAD test^†, median (IQR)	5.0 (3.0–10.0)	4.0 (3.0–9.0)	6.5 (3.0–11.0)	6.29	0.012
Slope value for Ct changes in NAD tests, median (IQR)	1.4 (0.5–2.2)	1.4 (0.3–2.2)	1.4 (0.8–2.1)	0.17	0.677
Proportion of slope value for Ct changes, n (%)				0.07	0.796
≤1.5	184 (56.6)	107 (56.1)	77 (57.5)
>1.5	141 (43.4)	84 (43.9)	57 (42.5)

Note: ^†The differences between males and females were statistically significant (P<0.05).

Abbreviations: SD, standard deviation; IQR, interquartile range; NAD, nucleic acid detection; Ct, cycle threshold.

Table 3 The Influencing Factors Associated with the Slope Value for Ct Changes Based on Linear Regression for Nucleic Acid Detection (NAD) Tests Among COVID-19 Patients in Shanghai, China

Variables	Percentage of Slope Value for Ct Changes>1.5	Model 1		Model 2
		OR	95% CI	OR	95% CI
Sex, n (%)
Male	84 (44.0)	1.06	0.68–1.66	1.16	0.72–1.87
Female	57 (42.5)	Ref		Ref
Age (years), n (%)
<45	73 (50.0)	2.32	1.34–4.02	2.49	1.41–4.41
45–59	40 (46.5)	2.02	1.09–3.73	2.58	1.34–4.95
≥60	28 (30.1)	Ref		Ref
Total virus NAD test times, n (%)
≤5 times	108 (45.4)	1.35	0.82–2.25	1.78	0.78–4.08
>5 times	33 (37.9)	Ref		Ref
Days of hospitalization, n (%)
≤15 days	112 (48.7)	2.16	1.30–3.59	3.81	1.67–8.70
>15 days	29 (30.5)	Ref		Ref

Notes: Model 1: univariate logistic regression, Model 2: multivariate logistic regression. Bold & italicized values indicate that there was a significant difference between groups.

Abbreviations: OR, odds ratio; CI, confidence interval; NAD, nucleic acid detection; Ct, cycle threshold.

Figure 1 The distribution of the time interval for each nucleic acid detection (NAD) test was based on setting Time 1 (T1) as the baseline among patients of different sexes and ages with COVID-19 infection.

Figure 2 Comparison of minimum, maximum, median, and mean individual cycle threshold (Ct) values among COVID-19 patients of different sexes and ages.

Figure 3 The cycle threshold (Ct) value for each nucleic acid detection (NAD) test among patients of different sexes and ages with COVID-19 infection.