Objective: To determine whether offering self sampling of cervicovaginal material for high risk human papillomavirus (HPV) testing is an effective screening method for women who do not attend regular cervical screening programmes.
Design: Cohort study (the PROHTECT trial). Settings Noord-Holland and Flevoland regions of the Netherlands, December 2006 to December 2007, including 13 laboratories, gynaecologists, and more than 800 general practitioners.
Participants: 28 073 women who had not responded to two invitations to the regular cervical screening programme: 27 792 women were assigned to the self sampling group and invited to submit a self collected cervicovaginal sample for HPV testing; 281 were assigned to the recall control group and received a second re-invitation for conventional cytology.
Intervention: Women with a positive result on the high risk HPV test on their self sample material were referred to their general practitioner. Women with abnormal results on cytology were referred for colposcopy. Women with normal results on cytology were re-evaluated after one year by cytology and high risk HPV testing and referred for colposcopy if either result was positive.
Main outcome measures: Attendance rate in both groups and yield of cervical intraepithelial neoplasia grade II/III or worse (>or=CIN II/>or=CIN III) in self sampling responders.
Results: The compliance rate in the self sampling group was significantly higher than in the control group (crude 26.6% v 16.4%, P<0.001; adjusted 27.5% v 16.6%, P<0.001). The number of detected >or=CIN II and >or=CIN III lesions in self sampling responders was 99 (1.3%) and 76 (1.0%), respectively. Self sampling responders who had not participated in the previous round of screening (43%) had increased relative risks of >or=CIN II (2.04, 95% confidence interval 1.27 to 3.28) and >or=CIN III (2.28, 1.31 to 3.96) compared with self sampling women who had been screened in the previous round (57%).
Conclusions: Offering self sampling by sending a device for collecting cervicovaginal specimens for high risk HPV testing to women who did not attend regular screening is a feasible and effective method of increasing coverage in a screening programme. The response rate and the yield of high grade lesions support implementation of this method for such women. Trial registration ISRCTN45527158.