Purpose: To retrospectively compare recall and cancer detection rates between immediate and subsequent batch methods for interpretation of screening mammograms.
Materials and methods: Institutional review board approval was obtained, and informed consent was waived. Retrospective analysis was performed for 8698 screening mammograms obtained between January 1 and October 31, 2001, which were interpreted either immediately (n = 4113) or subsequently with batch method (n = 4585). Data were collected from data reporting system and patient billing records. Patients with high risk factors were excluded; 3441 patients were in the immediate group, and 3932 were in the batch group. The two groups were compared with respect to age, breast density, and availability of comparison films with Wilcoxon rank sum test. Recall rates and cancer detection rates for each group were determined and compared with Pearson chi(2) test; false-negative rates were compared with Fischer exact test.
Results: A significant difference (P < .001) was noted in recall rates between immediate (18%) and batch (14%) groups; however, no significant difference (P = .7) was noted in cancer detection rates (immediate, 0.5%; batch, 0.4%). Mean age of patients was 56.8 years (age range, 21-96 years) in the immediate group and 56.2 years (age range 24-98 years) in the batch group (P = .02). Comparison of breast densities between groups indicates no statistically significant difference (P = .4). The batch group had significantly fewer comparison mammograms (3106 [79%]) available than the immediate group (2856 [83%]) (P < .001). There was no significant difference in false-negative rates between the immediate group (0.1%) and the batch group (0.1%) (P > .99).
Conclusion: Immediate interpretation of screening mammograms resulted in a statistically significant increase in recalls and additional clinical work-ups of perceived abnormalities; however, no significant difference in cancer detection rate was detected between groups.
(c) RSNA, 2005.