The association of HBV infection and head and neck cancer: a systematic review and meta-analysis

BMC Cancer

Table 2 Results of meta-analysis for subgroup with or without adjustment

Subgroup analysis	Studies, no.	Analysis model	Pooled OR (95% CI)	p value^*	Study Heterogeneity				Egger’s test	Begg’s test
Subgroup analysis	Studies, no.	Analysis model	Pooled OR (95% CI)	p value^*	χ²	dƒ	I², %	p value^*	Egger’s test	Begg’s test
Before adjustment
Excluded HIV and HCV	5	M-H, Random	1.46(1.13, 1.88)	0.004	29.50	4	86	< 0.00001	0.019	0.086
After adjustment for age and gender
Cancer site	19	IV, Random	1.39(1.19, 1.62)	< 0.0001	42.64	18	58	0.0009	0.333	0.441
Oral cavity	6	IV, Fixed	1.24(1.05, 1.47)	0.01	9.30	5	46	0.10	0.461	1.000
Nasopharynx	4	IV, Fixed	1.41(1.26, 1.58)	< 0.0001	4.30	3	30	0.23	0.382	0.734
Oropharynx	2	IV, Random	1.82(0.66, 5.05)	0.25	6.79	1	85	0.009	/	/
Hypopharynx	3	IV, Fixed	1.33(0.88, 2.00)	0.17	1.97	2	0	0.37	/	/
Larynx	4	IV, Random	1.25(0.69, 2.24)	0.46	16.46	3	82	0.0009	/	/
Excluded HIV and HCV	5	IV, Random	1.24(1.01, 1.51)	0.04	9.66	4	59	0.05	0.363	0.462
After adjustment for age, gender, alcohol use and smoking
Head and neck cancer	6	IV, Fixed	1.26(1.15, 1.38)	< 0.00001	9.17	5	45	0.10	0.654	0.721
Excluded HIV and HCV	3	IV, Fixed	1.17(1.01, 1.35)	0.03	0.92	2	0	0.63	/	/

M-H = Mantel-Haenszel; IV = inverse variance; OR = odds ratio; CI = confidence interval; dƒ = degree of freedom;
^*Statistical significant results are shown in bold

ISSN: 1471-2407