Context:

In France, cervical cancer (CC) screening was opportunistic until recently. The target population includes women aged 25 to 65 years. About 66% of women aged 25-40 years have performed a screening test over the last three years but this figure decreases to 55% in women over 40. The third "Cancer Plan" proposed by the French National Institute for Cancer recommends to achieve an 80% participation in eligible women.

Improving women compliance to CC screening is a major challenge to decrease cancer incidence and mortality.

To improve patient adherence, a CC screening organization will be launched in 2020 at a national scale in France. Women who did not perform a PAP test over the last 3 years will receive an invitation letter from the local public health association in charge of cancer screening organization. The invitation letter will remind women that they should consult a healthcare professional (a general practitioner (GP), a gynecologist or a midwife) to perform a screening test.

Providing GPs with a list of their non-adherent patients could also improve women compliance to CC screening recommendations.

The study objective is to assess whether sending both an invitation letter to non-adherent women and a list of their non-adherent patients to GPs ("invitation letter + GP reminder" group) could increase the proportion of women who perform a screening test, compared to only sending an invitation letter to non-adherent women ("invitation letter" group) or not sending any invitation ("usual care" group).

Design, Setting and Participants:

The investigators will conduct a 3-arm, cluster-randomized, controlled trial in the Loire-Atlantique region, in France.

The study will include a total of 1,500 GPs and about 100,000 women. The randomization will be based on GP practices to avoid a contamination bias resulting from shared tracking mechanisms and communication between GPs within a given practice. Thus, several GPs working in the same practice will be assigned to the same study arm. Women on the patient list of a given GP will be assigned to the arm of this GP.

Intervention:

After a cluster randomization according to the practice, the GPs and their female patients will be included in one of the following 3 arms:

• "Invitation letter + GP reminder" (Arm 1): 40-65 year-old women who did not perform a PAP test over the last 3 years will receive an invitation to consult a health professional to perform a screening test, AND GPs will receive the list of their 40-65 year-old patients who did not perform a PAP test over the last 3 years;
• "Invitation letter" (Arm 2): 40-65 year-old women who did not perform a PAP test over the last 3 years will receive an invitation to consult a health professional to perform a screening test. GPs will NOT receive any list of their non-adherent patients.
• "Usual care" (arm 3): 40-65 year-old women who did not perform a PAP test over the last 3 years will NOT receive any invitation to consult a health professional to perform a screening test. GPs will NOT receive any list of their non-adherent patients.

Expected Results

The investigators expect an increase in the proportion of women who perform a screening test in the intervention arm (arm 1), compared to arms 2 and 3. Previous studies have suggested that the proportion of women adherent to CC screening could be increased by 25% in arm 1 compared to arm 3, whereas the participation could be increased by 15% in arm 2 compared to arm 3.

Considering that the proportion of adherent women in arm 3 should be of about 55%, the absolute increase in participation could reach 11% in arm 1, and 6.6% in arm 2.

A higher adherence to CC screening could improve the detection of pathological lesions by 5% for pathological pap smears and by 10% for positive HPV tests.

Inclusion Criteria for GPs:

- All GPs practicing in the Loire-Atlantique region (Western France) will be included.

Inclusion criteria for patients :

• women aged 40 to 65 years,
• being on the patient list of the GPs participating in the study,
• living in the Loire-Atlantique region (Western France),
• being affiliated to the National Health Insurance.

Exclusion Criteria for GPs:

- GPs who could refuse to participate by contacting the research team.

Inclusion criteria for patients :

• Refusal to participate to the study
• Female patients who underwent total hysterectomy and those who received a pathological result of a previous pap smear (asc-us or CIN) are not eligible to participate in the CC screening and therefore excluded from the study.
• Women not registered with a GP located in Loire-Atlantique will not be included.