Impact of altering the invitation package on screening participation among never-screeners in the Flemish population-based cancer screening programs

The total coverage of both the Flemish breast cancer and cervical screening program remain suboptimal, with approximately 63% for both. Of all the women invited to the breast cancer screening program, 14.1% never underwent any type of breast cancer screening (any type of mammogram, ultrasound, or clinical breast examination). For the cervical cancer screening, this proportion of 'never-screeners' is 12.1%. We conducted two randomized controlled trials to assess whether various communication and presentation styles in the invitation package, were effective at motivating women who had never participated to attend.

The study population was limited to never-screeners (women who had never participated in the screening program). The RCT embedded in the breast cancer screening consisted of seven intervention arms and one control arm (all of them included a fixed appointment by letter). The RCT embedded in the cervical cancer screening consisted of three intervention arms and two control arms. In both RCTs, several content and style adaptations were made to the invitation letter, information leaflet, and envelope.

None of the intervention arms in either the breast cancer screening or the cervical cancer screening had a statistically significant impact on the participation rate compared to 'usual care' (the regular invitation package used in the screening program).

Sending adapted invitation packages to never-screeners, from the Flemish breast and cervical cancer screening program, does not seem to be effective in increasing the proportion of women screened. Innovative methods are needed to motivate never-screeners to be screened.