The ESSAG-trial protocol: A randomized controlled trial evaluating the efficacy of offering a self-sampling kit by the GP to reach women underscreened in the routine cervical cancer screening program

Background: In Flanders (Belgium), women not screened for cervical cancer (CC) within the last three years receive an invitation letter from the regional screening organization, the Centre for Cancer Detection (CCD), encouraging them to have a cervical specimen taken by their general practitioner (GP) or gynecologist. However, the coverage for CC screening remains suboptimal (63%). The offer of a self-sampling kit (SSK, for HPV testing) by a GP may trigger participation among women who do not attend regular screening. Methods: The ESSAG-trial is a cluster-randomized controlled trial with three arms, each including 1125 women aged 31-64 years, who were not screened for CC in the last 6 years. In arm A, GPs offer a SSK when eligible women consult for any reason. In arm B, women receive a personal GP signed invitation letter including an SSK at their home address. In the control arm, women receive the standard invitation letter from the CCD. The primary outcome is the response rate at three months after inclusion. Secondary outcomes are: screen test positivity; compliance with foreseen follow-up among screen-positives; costs per invited and per screened women; as well as contrasts between trial arms and between socio-demographic categories. Conclusion: The ESSAG-trial will assess the effect of GP-based interventions using SSKs on CC screening participation among hard-to-reach populations. Findings will inform policymakers about feasible strategies on increasing CC screening that may be rolled-out throughout the whole region. Trial registration: ClinicalTrials.gov: NCT05656976