In this cohort study nested in the organized cervical screening program, all women who had not participated in the organized screening program for at least 10 years in one Swedish county were eligible. Women were identified through the screening hub register that administrates for all invitations, referrals, and monitoring of the cervical screening program. The county screening hub invites approximately 30 000 women yearly to routine screening. Those who had opted out of the screening program, undergone hysterectomy, or changed their personal identification number (PNR) were excluded. HPV self-sampling kits with instructions and invitation letters were sent from the Department of Laboratory Medicine, Falun Hospital, in batches over 4 weeks. Lists of invitees were checked against changes in the screening hub register for individuals who moved, emigrated, died, or had taken a routine screening sample before sending a kit. Samples were received and HPV-analysis was performed.~If the self-sample HPV test was negative, the woman was returned to the screening program according to routine practice. HPV-positive women were referred without triage for further investigation to a gynecologist responsible for the clinical follow-up of high-risk women. The gynecological examination included colposcopy as well as biopsies and a liquid based cytology (LBC) sample (analyzed for cytology and HPV), which are routine examinations in clinical practice according to national and international guidelines. Colposcopies were performed within 3 months of a positive self-sample. If the colposcopic examination or the cytological/histopathological results indicated high-grade squamous intraepithelial lesions (HSIL) or invasive cervical cancer, women underwent treatment by conization and/or hysterectomy according to national guidelines The Cobas® PCR Female Swab Sample Packet was used for self-sampling, as previous studies had determined that the sensitivity for HPV was high and comparable with cervical samples used in the organized screening program. The HPV analysis was performed at the Department of Laboratory Medicine, Falun Hospital using the Cobas 4800 HPV Test (Roche Molecular Systems, South Branchburg, New Jersey, USA).
All women in one Swedish county who had not participated in the organized screening program for at least 10 years were sent an HPV self-sampling kit. Women who were positive for HPV were referred to a gynecological examination including colposcopy and further testing according to national guidelines.