Table 1

Characteristics of participants in the study and univariate analysis results

Variables/values	Sample size (n)	%	HBsAg positive (n)	Prevalence (%)
Age**	16 601	–	670	4.04
Gender
Male	7881	47.47	324	4.11
Female	8720	52.53	346	3.97
Educational level**
Primary school or lower	7346	44.25	305	4.15
Junior school	5431	32.71	265	4.88
High or polytechnic school	2736	16.48	76	2.78
College or higher	1088	6.55	24	2.21
Occupation**
Agriculture-based primary industry	5862	35.31	256	4.37
Manufacturing-based secondary industry	623	3.75	39	6.26
Service-based tertiary industry	2423	14.60	132	5.45
Other (students or retired)	7693	46.34	243	3.16
Living status**
Single living	5299	31.92	81	1.53
Non-single living	11 302	68.08	589	5.21
Medical insurance
Out-of-pocket	339	2.04	13	3.83
Has medical insurance	16 262	97.96	657	4.04
History of taking hepatitis B examinations*
Yes	2238	13.48	71	3.17
No	14 363	86.52	599	4.17
History of surgery**
Yes	575	3.46	48	8.35
No	16 026	96.54	622	3.88
History of blood transfusion
Yes	94	0.57	4	4.26
No	16 507	99.43	666	4.03
Vaccination history of hepatitis B**
Yes	6358	38.30	122	1.92
No	10 243	61.70	548	5.35
History of being away for 3 months
Yes	843	5.08	39	4.63
No	15 758	94.92	631	4.00
Family history of hepatitis B**
Yes	446	2.69	69	15.47
No	16 155	97.31	601	3.72
Living in coastal area**
Yes	5817	35.04	296	5.09
No	10 784	64.96	374	3.47
District**
Putuo	4370	26.32	154	3.52
Shaoxing	5416	32.62	197	3.64
Tonglu	3523	21.22	131	3.72
Tongxiang	1845	11.11	46	2.49
Yuhuan	1447	8.72	142	9.81