Table 2.

Multivariate analysis for factors of virologic response (undetectable in polymerase chain reaction assay)

Variables	HR	95%CI	P value1
Male gender	0.958	0.621-1.477	0.846
HBeAg (+)	0.668	0.415-1.077	0.098
HBV DNA (log10 IU/mL)	0.810	0.644-1.018	0.071
AST (IU/L)	1.000	0.998-1.002	0.955
ALT (IU/L)	1.000	0.999-1.002	0.606
Duration of prior lamivudine treatment (mo)	1.011	0.998-1.024	0.112
Inadequate response2	0.121	0.069-0.212	< 0.001
Treatment group3 "Add-on" vs "switch/combination"	1.646	1.080-2.510	0.021

¹P-values were calculated with the Cox’s proportional hazard model; Variables with a P < 0.1 in the univariate analysis were included in the multivariate analysis;

²Inadequate response was defined as serum HBV DNA levels of 2000 IU/mL or greater at 6 mo of treatment;

³Patients were divided into two treatment groups: the "add-on" group, in which adefovir dipivoxil (adefovir) was added to ongoing lamivudine treatment due to lamivudine resistance, and the "switch/combination" group, in which lamivudine was first switched to adefovir and then re-added later as needed. HBeAg: Hepatitis B e Antigen; HBV DNA: Hepatitis B virus DNA; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; HR: Hazard ratio.