Reducing ethnic inequalities in bowel screening participation in New Zealand: A randomised controlled trial of telephone follow-up for non-respondents

Abstract

Objective To test whether a telephone follow-up service for high-needs ethnic groups increases bowel screening participation in non-responders to postal invitations. Methods Māori, Pacific, and Asian ethnicity individuals who failed to return a bowel screening test kit within four weeks of it being posted were randomly allocated (1:1) to a telephone active follow-up service or a control group. The active follow-up service made multiple attempts to contact the invitee and provide support. Participation rates at eight weeks’ post-randomisation were compared, and the effect of the intervention on overall participation rates was imputed. Results A total of 3828 eligible individuals were allocated to active follow-up and 3773 to the control group. The imputed potential overall increase in participation in the active follow-up group was 2.0% (95% CI = 0.6%–3.4%); however, the impact of follow-up varied significantly by ethnicity and deprivation. The imputed increase in participation was significant for Māori (5.2; CI = 1.8%–8.5%) and Pacific (3.6%; CI = 0.7%–6.4%), but not for Asian ethnicities (0.7%; CI=−1.1%–2.4%). In addition, the imputed increase was significant among high deprivation participants (3.9%; CI = 2.0%–5.9%), but not among low deprivation participants (0.3%; CI=−1.6%–2.2%). Conclusions Active follow-up led to higher bowel screening participation in Māori and Pacific but not in Asian ethnicities and was more effective in high deprivation subjects. Active follow-up significantly reduced but did not eliminate ethnic inequalities in bowel screening participation.