Table 3. Univariate analysis of b-EBV DNA and outcome variables (DFS, OS).

EBV DNAa	DFS(median)	P valueb	OS(median)	P valueb
4 Groups
UQ	13		13
Neg	62	0.0001	62	0.0001
Q	27		31
Q+	33.5		37.5
3 Groups
UQ, Q	23		26
Q+	33.5	0.0001	37.5	0.0002
Neg	62	62

^a EBV DNA was stratified into 4 and 3 groups: Neg, Negative (EBV DNA = 0); UQ, Positive but UnQuantifiable (0 < EBV DNA < 10² copies/mL); Q, Positive and quantifiable (10² ≤ EBV DNA ≤ 15 × 10² copies/mL); Q+, Strongly positive and quantifiable (EBV DNA > 15 × 10² copies/mL).

^b The categorical variables were assessed using non-parametric Kruskal Wallis ANOVA. Statistically significant P values (P<0.05) are highlighted.