Positive predictive value of mammography: comparison of interpretations of screening and diagnostic images by the same radiologist and by different radiologists.

OBJECTIVE: The purpose of this study was to evaluate whether the positive predictive value (PPV) after a recommendation for biopsy differs when one as opposed to more than one radiologist performs the workup after abnormal findings are discovered at screening mammography.
MATERIALS AND METHODS: Using data in a mammography registry for the years 1996-2005, we identified 6,391 diagnostic examinations with a recommendation for biopsy that were performed on a day other than the day of the screening examination. The PPV after a recommendation for biopsy was calculated for two scenarios. In the first scenario, the radiologist interpreting the diagnostic images had interpreted the screening images. In the second scenario, the radiologist read diagnostic images after another radiologist had read the screening images. We used conditional logistic regression analysis to perform within-radiologist comparisons, controlling for covariates known to be associated with PPV after a recommendation for biopsy.
RESULTS: Of the screening examinations with positive findings, 2,335 (36.5%) were scenario 1, and 4,056 (63.5%) were scenario 2. We found no difference between the two scenarios with respect to PPV after a recommendation for biopsy when we controlled for age, breast density, family history of breast cancer, history of breast procedures, time since last mammogram, use of ultrasound at any point in the workup after abnormal results of screening mammography, and interval in days between the screening and diagnostic studies.
CONCLUSION: Who interprets the follow-up images after screening mammograms show abnormal findings does not appear to be an important factor influencing the wide variability in PPV among radiologists.