Figure 1.

Positive predictive value (PPV) for breast cancer for women reporting features of the cancer to primary care (aged ≥40 years). 1) The top figure in each cell is the PPV when the feature is present. The two smaller figures represent the 95% CIs for the PPV. These have not been calculated when any cell in the 2×2 table was < 5 (invariably this was because too few controls had the feature). 2) The yellow shading is for symptoms with a PPV > 1.0%; the orange shading is when the PPV is >2.0%; and the red shading is for PPVs >5.0%. 3) The breast lump/pain column is the PPV when a woman has reported both a breast lump and breast pain at least once each during the year before the index date. ^aNipple retraction was only reported by 4 cases and 0 controls aged 40–49 years. Thus no PPV can be calculated, although it is likely to be high. ^bBreast lump and breast pain were reported by 8 cases and 0 controls. Again, no PPV can be calculated, but given the relatively large number of cases with this combination, it has been estimated as >5%.