Variations in pathways and resource use in follow-up after abnormal mammography screening: a nationwide register-based study

Purpose: Mammography screening reduces breast cancer mortality, but a successful screening programme depends on both high participation and a sufficient follow-up of abnormalities. This study investigated patterns of follow-up after abnormal screening mammography in Denmark, and whether the variation was associated with health care resource use. Methods: We included 19,458 women aged 50–69 years with an abnormal screening mammography during a 3-year period of 2014–2016. Women were followed until the end of 2018. Their follow-up pathway was categorized in terms of the timeliness, appropriateness (i.e. whether all recommended diagnostic tests were utilized), and the ratio of benign vs. malignant surgeries. Further, we estimated health care resource use including post-diagnostic imaging and surgery procedures. Results: Ninety-seven percent of women had a diagnostic follow-up test within 6 months and 94% of those had diagnostic procedures in accordance with the recommendations. The proportion with timely follow-up (i.e. within 1 month) was 83%, but varied significantly between administrative regions (p < 0.001), and also between women with a screen-detected cancer and those with a false-positive mammogram (87% vs. 81%, p < 0.001). The ratio between having a benign versus a malignant surgery was 1:8, but it varied depending on which tests were used for diagnosis. The average number of procedures was, generally, in accordance with the recommendations. Conclusion: In most cases, follow-up after abnormal screening mammography followed national recommendations. We nevertheless found that this was not always the case in certain subgroups and administrative regions.