Socioeconomic status & returning for a second screen in the Ontario breast screening program.

In a retrospective cohort study involving 57902 women initially screened between January 1, 1995 and December 31 1997 by the Ontario Breast Screening Program (OBSP), we examined the relationship between geographically derived socioeconomic status (SES) and returning for a second screen. We controlled for age, rurality, preferred language, initial mammography results, previous mammography history, and referral by a health professional. Although SES was related to returning, rurality was an effect modifier of this relationship, a finding not previously reported. Compared to women in the highest ('richest') quintile, urban women in the first and second quintile were less likely to return; this relationship was not found in rural women. Low SES women, particularly in urban areas, should be specifically targeted to increase their likelihood of re-attendance for breast cancer screening within an organized program.