Self-sample HPV tests as an intervention for nonattendees of cervical cancer screening in Finland: a randomized trial.

BACKGROUND Attendance in screening is an important determinant of cervical cancer. Previous experience on high-risk human papillomavirus (hrHPV) DNA testing on patient-obtained samples suggests a good effect among nonattendees of screening. We assessed the effects of self-sampling on attendance in the Finnish screening program. METHODS Nonattendees after the primary invitation in one municipality (Espoo) were randomized to receive either a self-sampling kit (2,397 women) or an extra invitation (6,302 women). One fourth (1,315 women) of reminder letter arm nonattendees also received a self-sampling kit as a third intervention. Main outcomes were increases in screening attendance and coverage. RESULTS The adjusted relative risk for participation by self-sampling as a second intervention in comparison to a reminder letter arm was 1.21 (95% CI: 1.13-1.30). Total attendance increased from 65% to 76% by self-sampling and from 65% to 74% with a reminder letter. Combining the interventions (reminder letter and then self-sampling) increased total attendance from 63% to 78%. One fifth of the participants in all three groups increased screening coverage (previous Pap smear ≥5 years ago or never). Self-obtained samples were more often HPV positive than provider-obtained ones (participants after primary invitation and reminder letter), 12% to 13% versus 7%. CONCLUSIONS Self-sampling is a feasible option in enhancing the attendance at organized screening, particularly as an addition to a reminder letter. IMPACT If self-sampling is used as a third intervention after two written invitations, the overall attendance in Finland could most likely reach the desired 80% to 85%.