Drs. Brodersen and Thorsen's letter refers to their review showing long-term effects of false-positive mammography results in only 2 studies (1). Their findings, paired with their concerns about the validity of measures used, led them to conclude that available measures were inadequate to detect long-term effects of false-positive results. We believe that their conclusion is incorrect, resulting from their decision to exclude many ad hoc measures in order to focus on those for which some information on validation was available. In our systematic review of 23 studies that met stringent quality criteria, we found that false-positive mammograms were consistently associated with poorer long-term outcomes on breast cancer–specific measures of well-being (for example, distress and anxiety). We chose to include breast cancer–specific measures, despite the fact that most were ad hoc, because we expected that they were more likely to detect effects of breast cancer screening than more general well-being measures with established validity. Although it is reasonable to be concerned that ad hoc measures could present problems for comparisons across studies, research supports the use of such measures to assess subclinical distress (2). In our systematic review, studies that used previously validated general distress measures that were not specific to breast cancer showed no discernable pattern of long-term effects of false-positive results. Thus, it seems that the more important issue is to make sure that the effects of false-positive results are assessed with breast cancer–specific measures of distress. We welcome the development of a better measure of breast cancer–specific distress that improves upon existing measures by establishing convergent and discriminant validity (3).

Drs. Brodersen and Thorsen seem to have misunderstood our finding of different long-term effects of false-positive mammograms on return for mammography in Europe relative to the United States. Although overall return for mammography was higher in the European studies (85%) than in the U.S. studies (60%), our paper focused on the finding that false-positive results increased return for mammography in the United States (relative risk, 1.07 [95% CI, 1.02 to 1.12]) but not in Europe (relative risk, 0.97 [CI, 0.93 to 1.01]). Although our rates of return are similar to rates previously published (4), we believe that our paper's more important contribution is highlighting the real and lasting effects of false-positive mammograms.

We appreciate the thoughtful comments by Drs. Geller and Pinckney that more accurately characterize mammography screening guidelines for European women age 40 to 49 years.