# Effect of direct mailing self-sampling kits on participation in the Dutch hrHPV-based cervical screening programme: a population-based study

## TL;DR

Sending self-sampling kits directly to people increased participation in cervical cancer screening in the Netherlands, especially among younger and first-time participants.

## Contribution

This study demonstrates that direct mailing of self-sampling kits significantly boosts participation in cervical cancer screening programs.

## Key findings

- Participation increased from 42.1% to 49.9% with the new policy.
- Self-sampling uptake rose sharply, especially among first-time participants and 30–34-year-olds.
- Reflex cytology participation among hrHPV-positive individuals slightly declined but did not affect overall participation rates.

## Abstract

In July 2023, the Dutch cervical cancer screening programme introduced direct mailing of self-sampling kits with invitations for 30-year-olds and with reminder for non-participants in other age groups after 12 weeks. This study evaluates the impact of this new policy on participation, self-sampling uptake, and follow-up testing.

Data from the national screening (ScreenIT) and pathology (Palga) databases were used. Individuals invited between July 11 and December 31, 2023, were compared to a control group from the same period in 2022. Primary outcomes included participation rates following invitation and reminder, time to participation, self-sampling uptake, reflex cytology participation among high-risk HPV(hrHPV)-positive self-sampling participants, and first-time participation. Analyses were stratified by age and screening history.

Overall participation increased from 42.1% (n = 330,413) in the control group to 49.9% (n = 327,376; RR: 1.19, 95% CI: 1.18–1.19) with the new policy. After primary invitation, the largest increase in participation from 30.6% to 40.3% was observed among 30-year-olds (RR: 1.32, 95% CI: 1.30–1.34). Vaginal self-sampling uptake increased from 21.9% to 61.9% (RR: 2.82, 95% CI: 2.79–2.85), with the largest uptake among first-time participants (previous non-attenders, 32.1%–78.1%; RR: 2.43, 95% CI: 2.35–2.51) and 30–34-year-olds (25.1%–83.7%; RR: 3.33, 95% CI: 2.25–3.40). The proportion of first-time participants increased from 6.8% in the control group to 9.1% with the new policy. Participation increased sharply in individuals aged 35+ after 12 weeks. Reflex cytology participation among hrHPV-positive self-sampling participants declined by 6% (from 93% to 87%; RR: 0.94, 95% CI: 0.93–0.95), but this did not affect the overall increase in participation rates.

Direct mailing of self-sampling kits is an effective strategy to increase participation in population-based cervical cancer screening programmes, especially among first-time invitees and previous non-attenders. Continued participation in reflex cytology among hrHPV-positive women remains essential to maximise the overall impact of the policy on screening effectiveness.

This study was funded by the National Institute for Public Health and the Environment.