From: Tumour suppressor gene methylation and cervical cell folate concentration are determinants of high-risk human papillomavirus persistence: a nested case control study
Cases
Controls
n
age [y]
Total cohort
482
30.05 ± 8.92
473
31.56 ± 9.49
Folate cohort
283
30.51 ± 9.46
273
30.10 ± 8.46
Methylation cohort
199
29.39 ± 8.08
200
33.56 ± 10.43