Efficacy of strategies to increase participation in cervical cancer screening: GPs offering self-sampling kits for HPV testing versus recommendations to have a pap smear taken - A randomised controlled trial.

Randomised controlled trials (RCTs) have demonstrated that HPV-based cervical cancer screening offers higher protection against cervical precancer and cancer compared to cytology-based screening [1,2]. An additional advantage of screening using HPV assays is that the test can be performed on a self-sample collected by the woman herself. Recent systematic reviews have shown that an HPV test on a vaginal self-sample is as accurate to detect cervical intra-epithelial neoplasia of grade 2 or worse (CIN2+) as an HPV test applied on a clinician-taken cervical sample, if a clinically validated PCR-based assay is used [3,4]. A particular interesting property of self-sampling is that it can be used as a strategy to reach women who do not participate in regular screening programmes [[5], [6], [7], [8], [9], [10], [11], [12]]. Taking a vaginal self-sample is an attractive alternative method to obtain a specimen for cervical cancer screening, both for non-attending women as well as for women who do participate in preventive programmes [13,14]. A systematic review of RCTs revealed that sending a self-sampling kit to women who were not or irregularly screened was more effective in generating a response than sending routine invitations or reminders to have a Pap smear taken by a clinician [12]. However, the gain in response is highly variable among studies and settings. Therefore, no universal recommendations can be formulated. Local pilot studies should be set up to identify a format of intervention that generates satisfactory results before the general roll-out of strategies that include offering self-sampling kits. This study reports the participation rates of a randomised controlled trial conducted in a general practitioner (GP) practice in Belgium. The current screening policy in Belgium is 3-yearly screening using Pap smears taken by a GP or gynaecologist. However, differences exist regarding the organisation of screening between the three Belgian Regions (Flemish, Brussels-Capital and Walloon region). Since 2013 there is an organized programme targeting women between 25 and 64 years old in the Flemish region which includes sending routine invitations to women who do not have a Pap smear registered less than three years ago. In the Brussels-Capital and Walloon region screening is offered opportunistically, meaning that participation depends on the initiative of the woman herself or the clinician. In 2006, the 3-yearly screening coverage was around 60% in Belgium [15]. With the current study we want to investigate how the non-participants (defined as women who do not have a Pap smear taken in the last three years) can be reached through the support of a GP. This was addressed by comparing the response of non-participants between two study arms: a) self-sampling arm where a self-sampling kit was directly offered by a GP and b) control arm where a GP gave a recommendation to have a Pap smear taken by a clinician (GP or gynaecologist).