Women who receive a false-positive result from mammography screening may briefly experience elevated levels of anxiety, but the effect soon wears off, according to an analysis published today in JAMA Internal Medicine.
The relative risks and benefits of routine mammography screening for women have been debated for decades. Last fall, the debate took on renewed urgency as the US Preventive Services Task Force announced it would revisit its existing recommendations regarding mammography. The task force’s recommendations are influential and may affect whether health plans cover mammography.
The latest study results suggest that a temporary increase in anxiety may be one adverse effect of the false positives that inevitably result from screening.
To assess how false positives affect women and their attitudes toward future screening, Anna N. A. Tosteson, ScD, of the Dartmouth Institute for Health Policy and Clinical Practice and Norris Cotton Center at the Geisel School of Medicine at Dartmouth, and colleagues analyzed survey data from more than 1000 women who participated in the Digital Mammographic Imaging Screening Trial (DMIST). They found that anxiety was higher among women who received a false-positive result than among those who did not, but this difference didn’t persist at 1 year after screening. Women who had received a false positive were more likely to plan to have future mammograms than those who did not. Women who reported higher anxiety about potential future false-positive results were more likely to express willingness to stay overnight for testing that would reduce the risk of false positives, than those who did not report such anxiety.
Tosteson discussed the findings with news@JAMA.
news@JAMA: Why did you decide to conduct this study?
Dr Tosteson: At the time, the DMIST was launched it was thought that digital mammography wouldn’t be better at detecting cancer, but we thought it would be better at reducing false positives. We wanted to be able to value false positives when assessing the cost of digital mammography.
news@JAMA: Was digital better at avoiding false positives?
Dr Tosteson: In DMIST, there was no difference [in false positives] between traditional and digital mammography screening. Other studies have found the false-positive rate is higher for some groups of women. But overall, there is not much difference between the 2 types of mammography. Now, nearly all mammograms in the United States are digital.
False positives are a fairly common experience for women participating in mammography.
news@JAMA: What did your study tell us about the effects of false positives on women?
Dr Tosteson: We found a measurable increase in personal anxiety that was time limited, but no difference in general well-being. This suggests false-positive exams cause anxiety that is time limited. This anxiety didn’t negatively influence women’s future screening preferences. That result seems to be a little surprising.
news@JAMA: How do these results compare with other studies?
Dr Tosteson: Ours was unique in that it used a measure of well-being used by economists. The measures we used were generally not cancer-related per se. Some of the studies that have found long-term anxiety after a false positive looked at cancer-specific concerns.
news@JAMA: What are the implications for physicians counseling women or for women considering mammograms?
Dr Tosteson: Women need to understand how common the false-positive mammogram experience is. We found elevated anxiety to be a time-limited effect of false-positive test results. Our study did make it clear that women would generally prefer tests not associated with false positives, but there were limits on how far they were willing to go to get such a test. The results could be a little reassuring to women.
At the same time, I think the results have some value for people doing economic evaluations of breast screening. These evaluations include the impact of mammography on quality of life. Our study showed false-positive mammograms don’t really impact quality of life in a measurable way.
news@JAMA: What do you think is the main take-home message from your results?
Dr Tosteson: With all the controversy about mammography screenings, women need to be educated about the benefits and harms. It’s going to come down to how individual women balance the harms and benefits. It does come down to a preference-sensitive decision.Our findings would certainly not make screening less cost effective for 40- to 49-year-olds, or 50- to 59-year-olds.