Working Paper: NBER ID: w25049
Authors: Amanda E. Kowalski
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 behavior 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.
Keywords: mammography; overdiagnosis; breast cancer; health economics; clinical guidelines
JEL Codes: C18; I1; I12
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Healthier and higher socioeconomic status (I14) | Mammography uptake (Y90) |
| Mammography uptake (Y90) | Overdiagnosis rates (I12) |
| Always takers (D16) | Overdiagnosis rates (I12) |
| Mammography uptake (Y90) | All-cause mortality (I12) |
| Mammography uptake (Y90) | Long-term all-cause mortality (I12) |