Incidence of cervical intraepithelial neoplasia in Estonia

This study aimed to assess the incidence of cervical intraepithelial neoplasia (CIN) by grade (CIN 1, CIN 2, CIN 3) and age in Estonia (a country with less developed cervical cancer screening program and high cervical cancer incidence).

This descriptive study uses data from a health insurance fund covering the whole country to estimate the incidence of CIN by grade. CIN case definition was based on specific diagnostic procedures (biopsy, pathological diagnosis, and colposcopy) and/or treatment procedures (excision, local destructive therapy, conization, and hysterectomy) with the CIN-specific diagnosis code (International Statistical Classification of Diseases, 10 Revision) reported on health care claims. Age-specific incidence rates were calculated together with the 95% CIs. Main outcome measure includes CIN grade-specific incidence rate per 1,000 women.

The estimates for CIN incidence per 1,000 women range from 0.68 to 2.83 for CIN 1, 0.63 to 1.24 for CIN 2, and 0.13 to 0.53 for CIN 3 for narrow (biopsy/pathological diagnosis based) and broad (any CIN-specific diagnostic procedure/treatment based) case definition criteria, respectively.

Our estimates for cervical dysplasia disease frequency and age distribution are in line with those from other developed countries. Administrative health care resources (such as health insurance fund data) are a valuable source for health research.