Preventing cervical cancer using HPV self-sampling: direct mailing of test-kits increases screening participation more than timely opt-in procedures - a randomized controlled trial

Mette Tranberg, Bodil Hammer Bech, Jan Blaakær, Jørgen Skov Jensen, Hans Svanholm, Berit Andersen

Cervical cancer screening participation remains insufficient in most countries. Our aim was to evaluate whether offering a HPV self-sampling kit, either mailed directly to the woman's home or using timely opt-in procedures for ordering the kit, increased screening participation compared with a standard second reminder. In this randomized, controlled effectiveness trial, 9791 Danish women aged 30-64 who were due to receive the second reminder were equally randomized to either: 1) direct mailing of a second reminder and a self-sampling kit (directly mailed group); 2) mailing of a second reminder that offered a self-sampling kit to be ordered by e-mail, text message, phone, or webpage (opt-in group); or 3) mailing of a second reminder to attend regular cytology screening (control group). In an intention-to-treat analysis, we estimated the participation rate at 180 days post intervention, by returning a self-sample or attending regular cytology screening. We calculated the proportion of women with a positive HPV self-sample who attended for cervical cytology triage at the general practitioner within 90 days. Participation was significantly higher in the directly mailed group (38.0%) and in the opt-in group (30.9%) than in the control group (25.2%) (participation difference (PD): 12.8%, 95% CI: 10.6-15.0% and PD: 5.7%, 95% CI: 3.5-7.9%, respectively). Within 90 days, 107 women (90.7%, 95% CI: 83.9-95.3%) with a HPV-positive self-sample attended follow-up. Offering the opportunity of HPV self-sampling as an alternative to regular cytology screening increased participation; the direct mailing strategy was the most effective invitation strategy. A high compliance with follow-up was seen. Current Controlled Trials NCT02680262 . Registered 10 February 2016.