The potential of a population register for addressing health inequities: an observational study using data linkage to improve breast cancer screening enrolment and participation in Indigenous Māori women in Aotearoa New Zealand.

BACKGROUND

Breast cancer screening in Aotearoa New Zealand (NZ) still has persistent inequitable coverage by ethnicity, especially for Indigenous Māori women. This project aimed to undertake systematic data linkage to identify and invite eligible Māori women to participate in breast screening.

METHODS

This is a cross-sectional observational study conducted in Northern New Zealand between 1/01/2020 and 30/06/2021. The BreastScreen Aotearoa (BSA) register was linked with the primary care data to identify and invite eligible Māori women (aged 45-69 years) to breast screening, who were not currently enrolled in BSA, and who were enrolled in BSA but had not been screened or overdue for breast screening. Invitations were sent through invitation letters, text messages and phone calls. Enrolment to BSA and screening participation at 15 and 18 months from the project's start date were reported.

RESULTS

Through the data linkage, 2295 women who were not enrolled in BSA were identified eligible for breast screening. Approximately half (n = 1086) of the women were contactable within 5 contact attempts. Of these contactable, 345 (32%) women were enrolled in BSA, 421 (39%) were screened at 15 months, increasing to 441 (41%) at 18 months from the project start. Among women who were previously enrolled but never screened or overdue for screening, 1470 women were eligible. Their contact details were updated through the data linkage, which facilitated BSA to contact them successfully for breast screening. Consequently, 305 (21%) of these eligible were screened at 15 months, and increased to 332 (23%) at 18 months.

CONCLUSIONS

The data linkage approach has evidenced the benefit of a population register to facilitate equitable access to breast screening services. Further work is needed on choices of combined approaches for optimising screening uptake equitably.