HPV Self-sampling for Women Who do Not Attend Cervical Cancer Screening Programme

This study aims to test the effectiveness and cost-effectiveness of two different strategies of home-delivered HPV self-sampling, in comparison to the standard of care strategy, to increase adherence to cervical cancer screening.

An experimental and population-based study will be implemented at three primary healthcare centers located in the Western Porto region: Cedofeita, Garcia de Orta, and Prelada. Eligible women will be randomized into a control group or an intervention group. The control group will correspond to the standard of care (invitation to screening in a clinical setting). The intervention group will be randomized into two subgroups: 1) a "directly mailed" group that will receive a self-sampling kit at their home addresses by post; 2) an "opt-in" group that will receive an invitation at home asking if they want to receive a self-sampling kit, with a pre-paid envelope to return the answer to this question. Women who answer "yes" will receive the self-sampling kit at their home addresses by post.

Self-sampling samples will be subjected to HPV genotyping. In parallel, high-risk HPV positive women will be called in by their family doctors to undergo screening in a clinical setting so that they can continue their clinical follow-up in the conventional pathway.

The goal of this randomized clinical trial is to test the effectiveness and cost-effectiveness of two different strategies of home-delivered HPV self-sampling to increase the adherence to cervical cancer screening in women who are overdue for cervical cancer screening, in comparison to the standard of care strategy.

The main questions this study aims to answer are:

* To test the effectiveness of an invitation strategy to improve the adherence to cervical cancer screening based on directly home-delivered HPV self-sampling tests + automated reminders, in comparison to the standard of care invitation.
* To test the effectiveness of an invitation strategy to improve the adherence to cervical cancer screening based on home-delivered HPV self-sampling tests using opt-in procedures for ordering the kit + automated reminders, in comparison to the standard of care invitation.
* To compare the cost-effectiveness between a) standard of care; b) directly home-delivered HPV self-sampling tests + automated reminders; and c) home-delivered HPV self-sampling tests using opt-in procedures for ordering the kit + automated reminders.

Eligible women will be randomized (1:1) into a control group and an intervention group:

* Control group: corresponds to the standard of care, which is an invitation to cervical cancer screening in a clinical setting, through a written letter, printed and sent by the primary healthcare unit where the women are registered.
* Intervention group: Women allocated to this group will be randomized (1:1) into two subgroups, described briefly as follows:

  * Intervention 1 (half of the intervention group): HPV self-sampling test mailed directly to the women's home address (directly mailed group), complemented with a SMS reminder. If a woman returns the sample, HPV-type genotyping will be performed. If High-Risk HPV (HR-HPV) is detected, women will be informed of the result and invited to take cervical cancer screening in a clinical setting by their family doctors. Subsequent follow-up will take place according to Portuguese guidelines.
  * Intervention 2 (half of the intervention group): An invitation is mailed to the women´s home address, offering a self-sampling kit, to be ordered by returning a prepaid envelope with the answer "yes" (opt-in group). In the event of a positive response, an HPV self-sampling test is mailed to the women's home, complemented with a SMS reminder. If a woman returns the sample, HPV genotyping will be performed. If HR-HPV is detected, women will be informed of the result and invited to take cervical cancer screening in a clinical setting, performed by their family doctors. Subsequent follow-up will take place according to Portuguese guidelines.

In Interventions 1 and 2, when HR-HPV is detected in the self-sampling test, this sample will be subjected to HPV-DNA methylation testing. If increased HPV DNA methylation is detected and the woman has yet not attended the conventional screening invitation by her family doctor, she will be informed by her family doctor that a new test has indicated an increased risk for cervical cancer and the need to attend a medical appointment will be reinforced.

Eligibility Criteria:
Inclusion Criteria:

* Women aged between 26 and 60 years old;
* Women eligible for cervical cancer screening whose screening is at least 1 year overdue.

Exclusion Criteria:

* No mobile phone number available at the National Health Service database;
* Foreign mobile phone number;
* No address available at the National Health Service database;
* Foreign address.