The random biopsy diagnosed 20.9 % ( 81/388 , 95 % confidence interval [ CI ] 16.9-25 .3 % ) and 18.9 % ( 45/238 , 95 % CI 14.1-24 .5 % ) of the total cervical intraepithelial neoplasia ( CIN ) grade 2 or worse and grade 3 or worse , respectively .