Table 2.
Comparison of oral EBV DNA Loads between NPC cases and Healthy Controls by subgroup analysis
| Variable | NPC cases | Healthy controls | P c | ||||
|---|---|---|---|---|---|---|---|
| N (%) | Mediana | Median (IQR)b | N (%) | Mediana | Median (IQR)b | ||
| Total | 968 | 9309 | 3.97 (0.00‐4.92) | 1656 | 33 978 | 4.53 (3.04‐5.45) | <.001 |
| Age | |||||||
| <40 | 265 (27.38) | 6128 | 3.79 (0.00‐4.77) | 511 (30.86) | 19 776 | 4.30 (2.39‐5.21) | <.001 |
| 40‐49 | 318 (32.85) | 7561 | 3.88 (0.00‐4.89) | 500 (30.19) | 19 490 | 4.30 (2.94‐5.39) | <.001 |
| 50‐59 | 269 (27.79) | 13 613 | 4.13 (0.00‐4.96) | 420 (25.36) | 66 577 | 4.82 (3.48‐5.74) | <.001 |
| ≥60 | 116 (11.98) | 24 384 | 4.39 (2.62‐5.17) | 225 (13.59) | 58 857 | 4.77 (3.54‐5.65) | .004 |
| P c | .028 | <.001 | |||||
| Sex | |||||||
| Female | 254 (26.24) | 3379 | 3.53 (0.00‐4.88) | 491 (29.65) | 7125 | 3.85 (0.00‐5.01) | .010 |
| Male | 714 (73.76) | 11 513 | 4.06 (0.00‐4.93) | 1165 (70.35) | 52 231 | 4.72 (3.34‐5.64) | <.001 |
| P c | .015 | <.001 | |||||
| Education | |||||||
| ≤6 | 237 (24.56) | 4178 | 3.62 (0.00‐4.72) | 225 (13.63) | 26 908 | 4.43 (2.89‐5.45) | <.001 |
| 7‐12 | 604 (62.59) | 12 505 | 4.10 (0.00‐4.99) | 891 (53.97) | 35 403 | 4.54 (3.04‐5.47) | <.001 |
| >13 | 124 (12.85) | 8519 | 3.93 (0.00‐4.96) | 535 (32.40) | 36 091 | 4.56 (3.07‐5.41) | .001 |
| P c | .042 | .606 | |||||
a
Median represents the median value of the oral EBV load copy number in per milliliter mouth washing.
b
Median (IQR) represents the log10 transformed median value and interquartile value of oral EBV load copy number in per milliliter mouth washing.
c
Mann‐Whitney U tests were used for comparison of oral EBV load between 2 groups and Kruskal‐Wallis tests were used for comparisons of oral EBV load among 3 or more groups.