Different primers used for detecting EBV prevalence in PCR analyses.

95% CI: confidence interval, OR: odds ratio.a: One study [10] was divided into six parts because samples from six different countries were tested. Three studies [11], [22], [30] were excluded because one [11] could not offer the EBV DNA prevalence detected by each primer, respectively, and the others [22], [30] only included 1 case.b: adjusted by normalizing the constituent ratio of region and DNA specimen of the Bam H1W group.c: one-sided, 97.5% confidence interval.d: exact confidence levels not possible with zero count cells.