Ineffective recruitment strategies for screening mammography: letterbox drops and invitations for friends

To test the effectiveness of two interventions to encourage women to attend for mammographic screening, four randomised trials of letterbox drops were conducted. Leaflets about the screening service (n = 3984) were distributed to households within defined areas. Attendance from the 79 streets where a drop was made was compared with attendance from 78 control streets before and after the drop. No major effects were found either within each trial or across trials. In the second intervention, 69 women who attended the service were offered invitations for two friends. An additional 21 attenders were approached with the offer of an incentive to recruit friends. Invitations included an explanatory letter with an appointment time, a pamphlet and a contact phone number. The final response rate was only 7% and an incentive of an instant scratch lottery ticket for the original attender did not improve the response. Thus we identified two interventions with no major effect in recruiting women to mammographic screening.