Determinants of false positive recall in an Australian mammographic screening program

We conducted a case-control study (n=30128) to assess the importance of clinical (e.g., family history, age, hormone replacement therapy (HRT) use and duration) and service-related characteristics (e.g., time since introduction of Kodak MINR2000 film, year of screen) for false positive (FP) recall at BreastScreen Victoria, Australia. There was an age-adjusted upward trend in FP recall rates with year of screen at first (odds ratio (OR) 1.11, 95% confidence interval (95% CI) 1.08-1.13) and subsequent rounds (OR 1.04, 95% CI 1.01-1.06). In the multivariate analysis, the upward trend only remained for first round and age and family history also remained statistically significant at first round. At subsequent rounds the time since introduction of MINR2000, age, strong family history of breast cancer, use of HRT, recall at previous screen and previous screen at more than 27 months were all important predictors of FP recall. The rise in FP rates with year of screen at first round screening is of concern and may require further training of radiologists to improve confidence when viewing films when there a no films for comparison.