Factors affecting participation in mammography screening

To assess factors influencing attendance or nonattendance at the first round of a population based mammography screening programme, in New Zealand.

Representative samples of women who responded to an invitation to attend screening, and women who did not respond, were interviewed by telephone, by an interviewer independent of the screening programme. The response rates in those identified were 98% for attenders and 86% for nonattenders, giving final samples of 191 and 174 respectively. However, more nonattenders could not be contacted or had no known phone number.

Reasons given for attendance were primarily the need for reassurance, to detect breast cancer early, and the fact that the programme was free, a pilot programme, or recommended by their family doctor. Seventeen percent of attenders had been influenced by positive reports from other women. Of the nonattenders, 7% were ineligible for mammography, 20% did not attend because of practical difficulties and convenience, and 20% expressed concern or fear of the procedure or were influenced by negative reports from other women. Attenders and nonattenders did not differ in regard to age, education, income, socioeconomic status, degree of worry when the invitation was received, or physical distance from their home to the screening centre, although nonattenders estimated the travel would take considerably longer than did attenders. Ninety percent of attenders intend to come to the second round of screening. Forty three percent of nonattenders intend to participate at future rounds of screening, this figure being 80% in those who did not attend because of logistic or convenience reasons, and 27% for those who did not attend because of fear or negative reports.

The main reasons given for nonattendance are approximately equally divided between practical difficulty, and negative attitude towards the process. Most of those who did not attend for reasons of convenience intend to participate at future rounds, so that overall almost half of nonattenders intend to participate at future rounds. Therefore we recommend that invitations for future screening rounds should be sent to women who do not participate in the first round of population based screening.