Objective: To determine the association between initial screen result and returning for a second screen in an organised breast screening programme for women with a biennial screening recommendation. Setting: Women who attended the Ontario Breast Screening Program (OBSP). Methods: A retrospective cohort study was conducted of 140,723 Ontario women aged 50 years ond older who had an initial screen at the OBSP between 1 July 1990 and 31 December 1995 and were followed until 30 June 1998. Rescreening rates at 36 months and risk ratio estimates were calculated using survival methods. Age of women, year of screen, region (within Ontario) and initial screen result were compared. For initial screen results, returning for a second screen was examined by integration of screening centre with an assessment programme and by modality of referral. Results: Women with a false-positive result were less likely to return for a second screen as were women aged 70 and older and those living in regions of Ontario with fewer OBSP screening centres. However, there were minimal differences in reattendance behaviour by initial screen result for women screened at the OBSP centre with an assessment programme. Conclusions: Integration of breast screening and assessment services improved reattendance of women with false-positive screen results within an organised screening programme.
False positive ketamine urine immunoassay screen result induced by quetiapine: A case report
