Screening mammography recall rate: does practice site matter?

To determine whether the screening mammography recall rate for individual radiologists varies as a function of imaging site.

Institutional review board-approved, HIPAA-compliant retrospective review of mammography audit data was performed between May 1, 2008, and September 1, 2011, for five radiologists with expertise in breast imaging interpreting mammograms at a community office practice and an academic referral hospital. Informed consent was waived. Both sites used full-field digital mammography and batch screening interpretation. Recall rates were calculated from audit data. Breast density, history of surgery or biopsy, and availability of prior mammograms were compared in a sample of 500 mammograms from each site by using χ(2) and two-sample t tests.

Radiologists interpreted a total of 74 297 screening mammograms between both sites during the study. The overall mean recall rate was 7.8% ± 0.2 (standard deviation). Overall recall rate at the community site was significantly lower than at the hospital site (6.9% ± 0.3 vs 8.6% ± 0.3, P < .001). Recall rates for each radiologist were also lower at the community site: 3.7% versus 6.5% (P < .001), 9.6% versus 12.0% (P < .001), 7.5% versus 9.1% (P = .01), 7.6% versus 11.5% (P < .001), and 5.6% versus 8.0% (P = .02). There was a significantly higher proportion of patients at the hospital site with a history of surgery (13.4% vs 5.6%, P < .001) and biopsy (7.0% vs 1.4%, P < .001) but no difference in the percentage with dense breasts or in the percentage with availability of prior mammograms. Mean patient age was lower at the hospital site: 56.1 versus 62.9 years (P < .001).

Recall rates were higher at the hospital site, probably primarily caused by patient population factors.