Women’s conceptual knowledge about breast cancer screening and overdiagnosis in Norway: a cross-sectional study

Abstract

ObjectiveTo investigate conceptual knowledge about mammographic screening among Norwegian women.DesignWe administered a cross-sectional, web-based survey. We used multiple-choice questions and a grading rubric published by a research group from Australia.SettingOur Norwegian-language survey was open from April to June 2020 and targeted women aged 45–74 years.Participants2033 women completed our questionnaire. We excluded 13 women outside the target age range and 128 women with incomplete data. Responses from 1892 women were included in the final study sample.Primary and secondary outcome measuresThe questionnaire focused on women’s knowledge about the breast cancer mortality reduction, false positive results and overdiagnosis associated with mammographic screening. The primary outcome was the mean number of marks assigned in each of the three themes and overall. There were three potential marks for questions about breast cancer mortality, one for false positives and six for overdiagnosis.ResultsMost women (91.7%) correctly reported that screened women are less likely to die of breast cancer than non-screened women. 39.7% of women reported having heard of a ‘false positive screening result’ and 86.2% identified the term’s definition; 51.3% of women had heard of ‘overdiagnosis’ and 14.8% identified the term’s definition. The mean score was 2.59 of 3 for questions about breast cancer mortality benefit and 0.93 of 1 for the question about false positive screening results. It was 2.23 of 6 for questions about overdiagnosis.ConclusionsMost participants correctly answered questions about the breast cancer mortality benefit and false positive results associated with screening. The proportion of correct responses to questions about overdiagnosis was modest, indicating that conceptual knowledge about overdiagnosis was lower. Qualitative studies that can obtain in-depth information about women’s understanding of overdiagnosis may help improve Norwegian-language information about this challenging topic.

Impact of Breast Cancer Awareness Month on Public Interest in the United States between 2012 and 2021: A Google Trends Analysis

“…The U.S. Preventive Services Task Force recommends that the decision to proceed with mammography for women aged 40 to 49 years be made based on clinical considerations of the woman and her preferences to balance the benefits and harms [38]. However, awareness about the overdiagnosis of breast cancer may not be sufficient in the general public [39]. Given the time constraints in primary care settings, information about mammography's harms may not always be provided to patients, especially those with limited health literacy [40].…”