Attendance rate

>= 60%
(ages 50-64)

>= 70%
(ages 50-64)

70%
(ages 50-69)

Retention rate

>= 75% screened in the previous round (ages 50-69); of those rescreened, > 90% to be screened biennially

Abnormal recall rate (%)*
    Initial screen
    Rescreen

9 (overall)

< 7
< 5

< 10
< 7

< 10
< 5

Cancer detection rate
    Initial screen
    Rescreen

>= 3xIR** (overall)

>= 3xIR**
1.5xIR**

>= 2.7*** per 1,000
>= 3.0*** per 1,000

> 5 per 1,000
> 2 per 1,000

Benign to malignant biopsy ratio
    Initial screen
    Rescreen

< 3:1 (overall)

< 2:1
< 1:1

< 3:1 (overall)¹¹

<= 2:1
<= 1:1

Detected invasive cancers that are small

> 50% (< 15mm)

25% (<=10mm)

>= 1.5 per 1,000
(< 15mm; initial screen)
>= 1.65 per 1,000
(< 15mm; rescreen)

> 8 per 10,000 (<= 10mm)

Percentage of cancers without lymph node invasion (%)

>= 70%

Detected cancers that are in situ
    Initial screen
    Rescreen

0.4 - 0.9 per 1,000
0.5 - 1.0 per 1,000

10-20%

Rate of cancers presenting between screening episodes

12 per 10,000 screened women within 2 years of screen

< 6 per 10,000 screened women within 1 year of screen

* Mammography alone as screening modality.
** IR = expected incidence rate in the absence of screening.
*** Invasive cancers only, excludes cancers that are purely in situ (noninvasive or intraductal).
^† The United Kingdom recalls women for mammography every 3 years.