A healthy woman has a routine mammogram to check for signs of breast cancer, and the results aren't normal. Her doctors run further tests, such as additional imaging or a biopsy. Ultimately, she gets a clean bill of health. But what is the emotional cost of the false-positive result?
This is the question that researchers try to answer in a study published online Monday by JAMA Internal Medicine. The authors examined data from a large clinical trial of digital mammography and concluded that false positives produced a "significant increase in anxiety," though it was only temporary.
The researchers focused on 1,028 women â “ 494 who had a false-positive reading on a mammogram and 534 others of similar age who were tested at the same medical centers but had clean results. None of women was diagnosed with breast cancer.
All of the women in the study completed questionnaires to assess their general health in the previous four weeks and their anxiety level at the time of their interviews. (The researchers attempted to talk to the women during the period after they were told their initial mammogram was concerning but before they learned there was nothing to worry about. However, some women weren't reached until after they knew they were OK.) All of the women were also asked about their breast-related medical care in the year after their mammograms.
At baseline and again at their one-year follow-up, women in both groups rated their overall health highly â “ scoring an average of 0.90 on a scale that ranged from a low of -0.11 to a high of 1.0.
However, women in the false-positive group had higher levels of anxiety. On a scale from 20 (least anxious) to 80 (most anxious), the women who had false-positive mammograms and were interviewed before they had their final results scored a 36, on average; those who were interviewed after they got the all-clear scored an average of 35. The women with totally normal mammograms scored 33, on average. The difference for the women with false positives was statistically significant (that is, too large to be due to chance).
After one year, the average anxiety score among all of the women with false-positive mammograms had dropped to 34, while the scores for the women with normal mammograms remained at 33, according to the study. Not surprisingly, women with false-positive mammograms had more breast-related medical treatment than women with normal mammograms. For instance, 14.6 percent of those in the false-positive group had biopsies, compared with only 1.1 percent of women with normal mammograms.
A commentary that accompanies the study makes the case that the researchers' choice of survey methods probably underestimated the true anxiety of the women who had false-positive test results.