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Abstract 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.
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Mammograms and Mortality: How Has the Evidence Evolved?
Decades of evidence reveal a complicated relationship between mammograms and mortality. Mammograms may detect deadly cancers early, but they may also lead to the diagnosis and potentially fatal treatment of cancers that would never progress to cause symptoms. I provide a brief history of the evidence on mammograms and mortality, focusing on evidence from clinical trials, and I discuss how this evidence informs mammography guidelines. I then explore the evolution of all-cause mortality relative to breast cancer mortality within an influential clinical trial. I conclude with some responses to the evolving evidence.
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- Award ID(s):
- 1350132
- PAR ID:
- 10484760
- Publisher / Repository:
- American Economic Association
- Date Published:
- Journal Name:
- Journal of Economic Perspectives
- Volume:
- 35
- Issue:
- 2
- ISSN:
- 0895-3309
- Page Range / eLocation ID:
- 119 to 140
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1257/jep.35.2.119
