False-Positive Result and Reattendance in the Ontario Breast Screening Program

Abstract

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. I n 2001, breast cancer was diagnosed in an estimated 7200 Ontario women and an estimated 2100 women will die from the disease. I Relative survival after diagnosis of breast cancer has been improving over time in Ontario." Evidence of a reduction in breast cancer mortality rate through screening comes from the results of several randomised controlled trials and subsequent meta-analyses of these trials.':" The Canadian Task Force on the Periodic Health Examination recommends screening for breast cancer by mammography and clinical breast examination (CBE) every one to two years for women aged 50-69. 5 In Ontario most medical services are covered under the provincially managed universal health insurance plan (OHIP). Only diagnostic mammography was an insured service under ORIP prior to 1990. In 1990, the Independent Health Facilities Act allowed for the establishment and licensing of private diagnostic radiology clinics and the existing mammography billing code could also be used for screening mammograms. At the same time, the Ministry of Health established the Ontario Breast Screening Program (OBSP), under the auspices of Cancer Care Ontario to deliver an organised breast screening programme within the publicly funded health care system. In Ontario, therefore, women can receive a screening mammogram through physician or self-referral to OBSP or through physician referral to an independent radiologist.Results from randomised controlled breast screening trials have shown that a significant reduction in mortality can only be achieved after 7-10 years of regular attendance by 70% of the women in the target age group."? An understanding of how various factors are a...

Influence of false-positive mammography results on subsequent screening: do physician recommendations buffer negative effects?

“…Other U.S. studies have shown that false-positives either had no effect on 31–33 or seemed to facilitate subsequent mammography use. 7,8 Our findings are more consistent with two Canadian 16,17 and several European studies 11–15 showing that false-positive results interfere with subsequent screening. Given controversy concerning the benefits and potential harms of mammography screening, 20 monitoring the effects of false-positive test results and whether physicians advise women to be screened should remain a public health priority.…”

“…11–15 Canadian studies also suggest a negative effect of false-positives on subsequent mammography screening. 16,17 …”

Impact of a False-Positive Screening Mammogram on Subsequent Screening Behavior and Stage at Breast Cancer Diagnosis

“…Several other studies from Europe and Canada found no difference in re-screening (13–16,27), and yet others have reported lower re-screening rates among FPs than among TNs (18–20,28–30). These inconsistent results suggest both secular and geographic variation in the impact of FP mammography on adherence to screening recommendations among the USA, Europe and Canada (21).…”

False-positive Mammographic Screening: Factors Influencing Re-attendance over a Decade of Screening

“…Several studies in the UK and Canada have shown that women undergoing false-positive mammography were less likely to return for a subsequent screening appointment. 1,7-9 However a systematic review of 23 studies found that US women who received a false-positive result were more likely to return for routine screening than those who received a normal result; 2 there was no difference among European women, and among Canadian women those with a false-positive assessment were less likely to return for screening.…”