Table 2.

Univariate analysis of COVID-19 infection.^a

Variables		Uninfected	Infected	Statistics	P
Gender	Male	120	223	3.32	0.068
	Female	195	469
Ageb		43(24)	39(24)	166455.50	0.072
Education level	Junior high school degree and below	32	42	6.75	0.149
	High school/vocational high school/technical secondary school degree	43	86
	Junior college degree	51	120
	Bachelor’s degree	170	388
	Master’s degree and above	19	56
Major of study or occupation related to healthcare	No	276	597	0.34	0.559
	Yes	39	95
Vaccinated	No	18	35	0.19	0.665
	Yes	297	657
Having received 2 or more doses	No	24	45	0.42	0.516
	Yes	291	647
Vaccine manufacturer	Each dose provided by Sinopharm (Beijing)	190	412	0.25	0.884
	Each dose provided by Sinovac	52	110
	Other	73	170
Having proper hand-washing habits	No	101	221	0.00	0.968
	Yes	214	471
Having the habit of wearing a mask	No	14	21	1.28	0.257
	Yes	301	671
Isolating patients with COVID-19 at home	No	60	200	10.98	<0.001
	Yes	255	492
Number of vaccine doses received	Unvaccinated	18	35	1.33	0.857
	1 dose	6	10
	2 doses	49	125
	3 doses	228	493
	4 doses	14	29
Annual household income per capitac	¥ ≤ 30,000 yuan	31	56	164305.00	0.178
	30,000 yuan < ¥ ≤ 50,000 yuan	35	109
	50,000 yuan < ¥ ≤ 100,000 yuan	74	160
	100,000 yuan < ¥ ≤ 200,000 yuan	95	209
	¥ > 200,000 yuan	80	158

^aCount data were presented as numbers, and the chi-squared test was performed for comparison between groups.

^bMeasurement data were presented as medians with interquartile ranges (IQRs), and comparison between groups was performed by the Wilcoxon rank sum test.

^cRanked data were presented as numbers, and the Wilcoxon rank sum test was performed for comparison between groups.