Human papillomavirus infection and gastric cancer risk: A meta-epidemiological review

Table 3 Subgroup analysis by nationality

		All	Chinese studies	Non-Chinese studies
All		5.80 (3.27-10.31) [60.0] <18>	7.86 (5.19-11.89) [0.0] <12>	1.97 (0.79-4.89) [56.8] <6>
Area
	Gastric	4.83 (2.64-8.83) [62.4] <14>	7.08 (4.60-10.89) [0.0] <10>	1.54 (0.60-3.92) [62.6] <4>
	Cardia	10.88 (5.42-21,8) [0.0] <5>	11.17 (5.34-23.35) [0.0] <3>	8.62 (0.88-84.8) [14.2] <2>
Sample
	FFPE	5.13 (2.55-10.34) [68.4] <12>	8.02 (4.74-13.6) [19.6] <8>	1.38 (0.45-4.16) [58.5] <4>
	FF	27.9 (3.70-211.7) <2>	31.0 (1.76-546.6) <1>	25.2 (1.45-439.1) <1>
Methods
	PCR	5.88 (3.00-11.52) [62.2] <16>	10.93 (6.44-18.5) [0.0] <10>	1.97 (0.79-4.98) [56.8] <6>
	ISH	6.23 (1.56-24.9) [64.0] <2>	6.23 (1.56-24.9) [64.0] <2>	-

Study: Summary odds ratio (95% confidence interval) [I² value (%)] <Number of selected studies>; FF: Fresh frozen tissue; FFPE: Formalin-fixed paraffin-embedded tissue; ISH: In situ hybridization; PCR: Polymerase chain reaction.