Clinical features of HBsAg seroclearance in hepatitis B virus carriers in South Korea: A retrospective longitudinal study

Table 1 Rate and time interval of hepatitis B surface antigen seroclearance from entry

Age group	Total number	1HBsAg seroclearance	Time interval to HBsAg seroclearance
	(sex ratio)	No. (rate/yr/sex ratio)	(yr, mean ± SD)
< 30	181 (1.8:1)	4 (2.2%/0.55%/3.0:1)	3.99 ± 2.91
30-40	423 (2.3:1)	11 (2.6%/0.45%/1.2:1)	5.79 ± 4.23
40-50	574 (2.9:1)	36 (6.3%/0.92%/4.0:1)	6.87 ± 3.5
50-60	455 (0.4:1)	22 (4.8%/0.79%/2.7:1)	6.15 ± 3.89
> 59	286 (1.1:1)	17 (5.9%/1.05%/0.9:1)	5.64 ± 3.14
Total	1919 (1.4:1)	90 (4.7%/0.76%/1.9:1)	6.2 ± 3.6

¹The overall rate of HBsAg seroclearance was 4.7%, and the estimated annual rate of HBsAg seroclearance was 0.76%. The rate of HBsAg seroclearance was significantly higher in the 40-50 and 50-60 year age groups than in the 20-30 and 30-40 year age groups (P = 0.001). Male predominance was observed in the 40s and 50s age groups but was not clear in the > 59 year age group. The time interval from entry to HBsAg loss was longer in the 40-50 and 50-60 year age groups than in the 20-30 and 30-40 year age groups.