Objective-To determine the socioeconomic, cultural, and clinical predictors of non-attendance for second round mammography. Design/participants-Retrospective cohort study of 121 889 women aged 50-69 years who attended for first mammography screening in the BreastScreen Victoria programme in 1995/1996 and who were recommended to be invited for routine biennial mammography. Women were considered to be non-attenders if they had not attended for rescreening within 27 months of their initial screening. Relative risk (RR) was used to compare categories for non-attendance for second screening, and a multivariate model was fitted to adjust for possible confounding. Setting-BreastScreen Victoria, a population based mammographic screening programme, which oVers free biennial mammography to all women 40 years and older. The programme specifically targets women aged 50-69 years. Results-In the multivariate analysis, women from non-English speaking backgrounds were more likely not to attend for second round screening (RR ranged from 1.18 to 1.77). Indigenous women (RR 2.02, 95% confidence interval (CI) 1.61 to 2.54) and women who reported either significant symptoms (RR 1.90, 95% CI 1.76 to 2.05) or other breast symptoms (RR 2.25, 95% CI 2.15 to 2.36) at the time of first round screening were also more likely not to attend for second round screening. Conclusions-Women from non-English speaking backgrounds, indigenous women, and women who report symptoms at the time of first screening are more likely to not attend for second round screening. It is important to investigate why these women do not attend for second round screening so that services can be more appropriately tailored to their needs. (J Med Screen 2000;7:190-194) Keywords: breast; cancer; mammography; attendance In Australia, breast cancer is the most common cancer in women (excluding non-melanocytic skin cancer) and accounted for 29% (9846 cases) of new cancers in women and 17% (2623 cases) of female cancer related deaths in 1996.1 Randomised controlled trials of mammographic screening have shown a 30% reduction in mortality in women aged between 50 and 69 years who are screened.2 Achieving this mortality reduction depends on achieving a screening rate of about 70% of the target population.3 In Victoria, Australia, in 1996 and 1997, 54.9% of women aged 50-69 years attended for screening. For women of non-English speaking background, this rate was 44.8%. 4 Not only should the programme aim to maximise participation in first round screening but, if a mortality reduction is to be achieved, women must also continue to participate in the programme. This requires recruiting women who are eligible for baseline screening and retaining them within the screening programme. Many studies have focused on factors associated with initial participation in breast screening. [5][6][7][8][9][10][11][12][13] The purpose of this paper is to identify predictors of non-attendance for second round screening in Victorian women who attended for first round screening.Adherence to...