Comparison of two invitation-based methods for human papillomavirus (HPV) self-sampling with usual care among un- and under-screened Māori, Pacific and Asian women: study protocol for a randomised controlled community trial to examine the effect of self-sampling on participation in cervical-cancer screening

Background Māori, Pacific and Asian women in New Zealand have lower cervical-cancer screening rates than European women, and there are persistent inequities in cervical cancer outcomes for Māori and Pacific women. Innovative ways to address access barriers are required. New Zealand is transitioning to screening with human papillomavirus (HPV) DNA testing, which could allow women themselves, rather than a clinician, to take the sample. Internationally, self-sampling has been found to increase screening participation rates. The aim of this open-label community-based randomised controlled trial is to investigate whether self-sampling increases screening participation among un- and under-screened Māori, Pacific and Asian women in New Zealand. Methods/design We aim to invite at least 3550 un- or under-screened (≥5 years overdue) Māori, Pacific and Asian women (1050, 1250, 1250 respectively), aged 30–69 years, for screening. The three study arms are: usual care in which women are invited to attend a clinic for a standard clinician-collected cytology test; clinic-based self-sampling in which women are invited to take a self-sample at their usual general practice; and mail-out self-sampling in which women are mailed a kit and invited to take a self-sample at home. Women will be randomised 3:3:1 to the clinic and mail-out self-sampling groups, and usual care. There is also a nested sub-study in which non-responding women in all allocation groups, when they subsequently present to the clinic for other reasons, are offered clinic or home-kit self-sampling. The primary outcome will be the proportion of women who participate (by taking a self-sample or cytology test). Discussion This trial is the first to evaluate the effectiveness of mailed self-sampling in New Zealand and will be one of the first internationally to evaluate the effectiveness of opportunistic in-clinic invitations for self-sampling. The trial will provide robust evidence on the impact on participation proportions from different invitation approaches for HPV self-sampling in New Zealand un- and under-screened Māori, Pacific and Asian women. Trial registration ANZCTR Identifier: ACTRN12618000367246 (date registered 12/3/2018) https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371741&isReview=true; UTN: U1111–1189-0531.