Behaviour within a Clinical Trial and Implications for Mammography Guidelines

• 成果类型: Article
• 署名作者: Kowalski, Amanda E.
• 署名单位: University of Michigan System; University of Michigan
• 刊物名称: REVIEW OF ECONOMIC STUDIES
• ISSN/ISSBN: 0034-6527
• DOI: 10.1093/restud/rdac022
• 发表日期: 2023
• 页码: 432-462
• 关键词: breast-cancer mortality; local instrumental variables; follow-up; preventive services; screening mammography; socioeconomic-status; selection bias; death rates; age 40; women

摘要

Mammography guidelines have weakened in response to evidence that mammograms diagnose breast cancers that would never eventually cause symptoms, a phenomenon called overdiagnosis. Given concerns about overdiagnosis, instead of recommending mammograms, US guidelines encourage women aged 40-49 to get them as they see fit. To assess whether these guidelines target women effectively, I propose an approach that examines mammography behaviour within an influential clinical trial that followed participants long enough to find overdiagnosis. I find that women who are more likely to receive mammograms are healthier and have higher socioeconomic status. More importantly, I find that the 20-year level of overdiagnosis is at least 3.5 times higher among women who are most likely to receive mammograms. At least 36% of their cancers are overdiagnosed. These findings imply that US guidelines encourage mammograms among healthier women who are more likely to be overdiagnosed by them. Guidelines in other countries do not.