Schematic flow chart for the screening and follow-up. Women will be examined by repeat cytology and HPV testing every 6 months. Compared with the previous results of the HPV testing, the next follow-up would yield four possible kinds of change in HPV infection type and the result of cytology will be categorized into two groups (<HSIL and ≥HSIL). ASCUS, atypical squamous cells of undetermined significance, LSIL, low-grade squamous intraepithelial lesion; HPV, human papillomavirus; HSIL, high-grade squamous intraepithelial lesion.