Characteristic	Screening episodes
Age (years)
40–49	142 700 (13.9%)
50–59	424 213 (41.3%)
60–69	356 073 (34.7%)
70 or more	103 151 (10.1%)
Socio‐economic status (IRSD), quintile
1st (most disadvantaged)	98 683 (9.6%)
2nd	231 500 (22.6%)
3rd	199 763 (19.5%)
4th	160 137 (15.6%)
5th (least disadvantaged)	331 041 (32.3%)
Postcode could not be classified	4228 (0.4%)
Postcode missing	785 (0.1%)
Time since previous screen (months)
First screen	148 499 (14.5%)
Less than 15	92 484 (9.0%)
15 to less than 27	591 503 (57.6%)
27 or more	193 651 (18.9%)
Breast density
Dense	235 476 (23.0%)
Not dense	703 213 (68.5%)
Unknown	87 448 (8.5%)
Personal history of breast cancer
Yes	39 086 (3.8%)
No	987 049 (96.2%)
No response	2 (< 0.1%)
Personal history of ovarian cancer
Yes	5319 (0.5%)
No	1 020 811 (99.5%)
No response	7 (< 0.1%)
First degree family history of breast cancer
Yes	211 742 (20.6%)
None	814 395 (79.4%)
Hormone replacement therapy (past 6 months)
Yes	121 189 (11.8%)
No	904 850 (88.2%)
No response	98 (< 0.1%)
Breast surgery/biopsy for benign conditions
Yes	182 562 (17.8%)
No	843 575 (82.2%)
Self‐reported breast symptoms
Yes	10 455 (1.0%)
No	1 015 682 (99.0%)
BreastScreen WA high risk category†
Yes	145 086 (14.1%)
No	881 051 (85.9%)

IRSD = Index of Relative Socio‐economic Disadvantage.