Incidence and prevalence of preclinical carcinoma of cervix in a British population.

Quantitative knowledge of the natural history of cancer of the cervix is essential to the design of optimal screening programmes. We have estimated the incidence and prevalence of cervical intraepithelial neoplasia in a population of women receiving cytological examinations, and compared the results with those from other series. Relative risk of disease is reported in relation to easily identified variables (marital status, parity, contraceptive use, symptoms) which are likely to be of practical value in defining selective screening policies.