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Systematic reviews with economic components are important decision tools for stakeholders seeking to evaluate technologies, such as breast cancer screening (BCS) programs. This overview of systematic reviews explores the determinants of the cost‐effectiveness of BCS and assesses the quality of secondary evidence. The search identified 30 systematic reviews that reported on the determinants of the cost‐effectiveness of BCS, including the costs of breast cancer and BCS. While the quality of the reviews varied widely, only four out of 30 papers were considered to be of a high quality. We did not identify publication bias in the original evidence on the cost‐effectiveness of mammography screening; however, we highlight a need for improved clarity in both reporting and data verification. The reviews consisted mainly of studies from high‐income countries. Breast cancer costs varied widely among the studies. Factors leading to higher costs included: time (diagnosis and last months before death), later stage or metastases, recurrence of the disease, age below 64 years and type of follow‐up (more intensive or more specialized). Overall, screening with mammography was considered cost‐effective in the age range 50‐69 years in Western European and Northern American countries but not for older or younger women. Its cost‐effectiveness was questionable for low‐income settings and Asia. Mammography screening was more cost‐effective with biennial screening compared to annual screening and single reading using computer‐aided detection vs double reading. No information on the cost‐effectiveness of ultrasonography was found, and there is much uncertainty on the cost‐effectiveness of CBE because of methodological limitations. [ABSTRACT FROM AUTHOR]

This systematic review, stimulated by inconsistency in secondary evidence, reports the benefits and harms of breast cancer (BC) screening and their determinants according to systematic reviews. A systematic search, which identified 9,976 abstracts, led to the inclusion of 58 reviews. BC mortality reduction with screening mammography was 15–25% in trials and 28–56% in observational studies in all age groups, and the risk of stage III+ cancers was reduced for women older than 49 years. Overdiagnosis due to mammography was 1–60% in trials and 1–12% in studies with a low risk of bias, and cumulative false‐positive rates were lower with biennial than annual screening (3–17% vs 0.01–41%). There is no consistency in the reviews' conclusions about the magnitude of BC mortality reduction among women younger than 50 years or older than 69 years, or determinants of benefits and harms of mammography, including the type of mammography (digital vs screen‐film), the number of views and the screening interval. Similarly, there was no solid evidence on determinants of benefits and harms or BC mortality reduction with screening by ultrasonography or clinical breast examination (sensitivity ranges, 54–84% and 47–69%, respectively), and strong evidence of unfavourable benefit‐to‐harm ratio with breast self‐examination. The reviews' conclusions were not dependent on the quality of the reviews or publication date. Systematic reviews on mammography screening, mainly from high‐income countries, systematically disagree on the interpretation of the benefit‐to‐harm ratio. Future reviews are unlikely to clarify the discrepancies unless new original studies are published. What's new? Multiple reviews of the benefits and harms of mammography have been used to inform breast cancer screening guideline development. This process, however, has led to inconsistent screening recommendations. Here, synthesis of results from systematic reviews based on original evidence of determinants of mammography benefits and harms reveals irregularities in data on magnitude of breast cancer reduction obtained with screening mammography. Evidence on determinants of benefits and harms of ultrasonography and clinical breast examination was lacking. Inconsistency in reviews' conclusions was affected by characteristics of the original evidence, indicating that new original studies are needed to clarify discrepancies in screening recommendations. [ABSTRACT FROM AUTHOR]