Hepatitis B and C virus infections and the risk of biliary tract cancers: a meta-analysis of observational studies

Table 1 Meta-regression analysis

Variables	Coefficient	Standard error	P value	95% CI	Proportion of explained sources of heterogeneity
HBV and BTC
Ethnicity	0.325	0.241	0.186	− 0.812 to 0.162	–
Study design	0.484	0.402	0.236	− 0.328 to 1.296	–
HBV and CCA
Ethnicity	− 0.350	.0263	0.191	− 0.883 to 0.182	–
Study design	0.551	0.520	0.296	− 0.502 to 1.605	–
HBV and ICC
Ethnicity	0.363	0.380	0.348	− 0.419 to 1.145	–
Study design	− 0.307	0.642	0.636	− 1.627 to 1.013	–
HBV and ECC
Ethnicity	− 0.032	0.292	0.914	− 0.650 to 0.587	–
Study design	0.460	0.710	0.526	− 1.966 to 1.045	–
HCV and BTC
Ethnicity	0.578	0.222	0.014	0.125 to 1.032	18%
Study design	0.073	0.352	0.837	− 0.793 to 0.647	–
HCV and CCA
Ethnicity	0.675	0.222	0.005	0.219 to 1.130	26%
Study design	0.006	0.420	0.989	− 0.855 to 0.867	–
HCV and ICC
Ethnicity	0.595	0.232	0.019	− 1.081 to − 0.109	46%
Study design	− 0.132	0.399	0.745	− 0.968 to 0.704	–
HCV and ECC
Ethnicity	− 0.594	0.234	0.025	− 1.100 to − 0.089	35%
Study design	0.249	0.667	0.715	− 1.689 to 1.191	–

CCA, cholangiocarcinoma; CI, confidence interval; ECC, extrahepatic cholangiocarcinoma; HBV, hepatitis B virus; HCV, hepatitis C virus; ICC, intrahepatic cholangiocarcinoma

ISSN: 1750-9378