Table III.

Summary of results.

Parameter	Studies, n	Study design	Case/control	OR (95% CI)	P-value	P-value of heterogeneity	I2, %	P-valuea
Total	24	Case-control	971/1085	2.27 (1.40–3.69)	0.001	0.022	43.0
HPV DNA methods								NA
PCR	22	Case-control	945/1015	2.27 (1.40–3.69)	0.001	0.022	43.0
No PCR	2	Case-control	26/70	NA	NA	NA	NA
Year of publication								0.53
1990–1999	13	Case-control	440/423	1.92 (0.85–4.35)	0.117	0.046	47.7
2000–2015	11	Case-control	531/662	2.65 (1.47–4.87)	0.001	0.113	37.0
Geographical region								0.08
Asia	8	Case-control	459/539	2.96 (1.56–5.64)	0.001	0.257	22.6
Europe	7	Case-control	213/236	2.29 (1.17–4.47)	0.015	0.457	0.0
North America	6	Case-control	197/205	1.05 (0.47–2.36)	0.904	0.298	18.6
South America	1	Case-control	41/30	43.57 (2.49–761.57)	0.010	NA	NA
Oceania	2	Case-control	61/21	1.84 (0.09–38.67)	0.694	0.018	82.8
Type of tissue								0.21
Frozen	12	Case-control	385/435	1.62 (0.75–3.74)	0.216	0.052	48.0
Formalin-fixed	12	Case-control	586/650	2.98 (1.68–5.30)	0.000	0.184	27.3

^aStratified pooled analyses were used to assess the subgroup differences. OD, odds ratio; CI, confidence interval; NA, not available; HPV, human papillomavirus; PCR, polymerase chain reaction.