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. 2022 Jul 14;24:49. doi: 10.1186/s13058-022-01545-9

Table 1.

Characteristics of participants in the International Consortium on Mammographic Density

World Regiona: All women (n = 10,681) White (n = 4512) Black (n = 938) East Asian (n = 1837) South Asian (n = 1133) Mestizo (n = 333) Hawaiian (n = 142) Middle Eastern (n = 1786)
n [column %] unless stated otherwise
Per cent density (cm2)
 Median (IQR) 20 (11–31) 22 (16–35) 17 (10–26) 24 (16–35) 16 (8–25) 20 (13–27) 18 (9–32) 16 (8–24)
Dense area (cm2)
 Median (IQR) 27 (16–41) 27 (17–42) 34 (20–49) 24 (15–35) 22 (12–35) 28 (18–42) 25 (12–38) 29 (16–43)
Age at mammogram (years)
 Mean (SD) 52.7 (8.2) 53.8 (7.7) 52.4 (8.5) 52.1(8.5) 53.6 (7.2) 44.2 (6.4) 55.1 (7.5) 51.4 (8.5)
 IQR 47–58 49–59 46–58 45–58 49–59 40–49 50–61 45–57
Age at menarche (yrs)b
 < 12.0 1470 [14] 838 [19] 80 [9] 166 [9] 153 [14] 77 [23] 20 [14] 136 [8]
 12.0–12.9 2588 [24] 1031 [23] 116 [12] 437 [24] 300 [26] 87 [26] 56 [39] 561 [31]
 13.0–13.9 2594 [24] 1185 [26] 167 [18] 350 [19] 283 [25] 73 [22] 0 [0] 536 [30)
 14.0–14.9 2023 [19] 848 [19] 182 [19] 425 [23] 165 [15] 46 [14] 47 [33] 310 [17]
 ≥ 15.0 2006 [19] 610 [14] 393 [42] 459 [25] 232 [20] 50 [15] 19 [13] 243 [14]
 Mean age (SD) 13.2 (1.7) 12.9 (1.6) 14.2 (2.1) 13.5 (1.8) 13.2 (1.7) 12.7 (1.7) 12.9 (1.8) 13.0 (1.4)
Height (cm)
 < 155 2760 [26] 685 [15] 186 [20] 704 [38] 663 [59] 113 [34] 17 [12] 392 [22]
 155–159.9 2609 [24] 905 [20] 211 [22] 604 [33] 268 [24] 125 [38] 15 [11] 481 [27]
 160–164.9 2759 [26] 1299 [29] 287 [31] 395 [22] 136 [12] 70 [21] 42 [30] 530 [30]
 > 165 2553 [24] 1623 [36] 254 [27] 134 [7] 66 [6] 25 [8] 68 [48] 383 [21]
 Mean height (SD) 159.4 (7.2) 162.0 (6.9) 160.6 (7.6) 156.4 (5.6) 153.2 (6.8) 157.0 (5.3) 163.2 (6.0) 159.4 (6.3)
 % of measured heightsc 66 57 39 57 85 98 0 100
BMI
 ≤ 20.0 642 (6) 208 (5) 9 (1) 284 (15) 95 (8) 3 (1) 2 (1) 41 (2)
 20.1–25.0 3920 (37) 1787 (40) 171 (18) 1086 (59) 376 (33) 82 (25) 43 (30) 375 (21)
 25.1–30.0 2342 (32) 1503 (33) 320 (34) 411 (22) 428 (38) 133 (40) 45 (32) 592 (33)
 > 30.0 2687 (25) 1014 (22) 438 (47) 56 (3) 234 (21) 115 (35) 52 (37) 778 (44)
 Mean BMI (SD) 27.0 (5.7) 26.7 (5.3) 30.3 (6.2) 23.2 (3.4) 26.3 (5.0) 28.7 (5.1) 28.9 (6.3) 29.6 (6.0)
Menopausal status
 Pre-menopausal 4361 [41] 1761 [39] 328 [35] 799 [43] 324 [29] 261 [78] 35 [25] 853 [48]
 Post-menopausal 6320 [59] 2751 [61] 610 [65] 1038 [57] 809 [71] 72 [22] 107 [75] 933 [52]
Ever used hormone therapyd
 Yes 2185 [25] 1387 [36] 133 [14] 384 [21] 82 [8] 27 [8] 78 [55] 94 [12]
 No 6681 [75] 2456 [64] 802 [86] 1425 [79] 969 [92] 291 [92] 64 [45] 674 [88]
Parity
 Nulliparous 1068 [10] 661 [15] 61 [7] 161 [9] 90 [8] 21 [6] 9 [6] 65 [4]
 Parous 9613 [90] 3851 [85] 877 [94] 1,676 [91] 1,043 [92] 312 [94] 133 [94] 1721 [96]
 Mean parity (SD) 2.6 (1.8) 2.4 (1.1) 3.3 (1.7) 2.5 (1.2) 3.9 (2.1) 2.9 (1.4) 3.3 (1.5) 3.6 (2.2)
Age at first birth (yrs)b
 Mean age (SD) 24.3 (5.1) 25.3 (4.7) 22.3 (4.8) 26.2 (4.2) 22.4 (6.2) 23.9 (5.0) 22.9 (4.1) 22.5 (5.2)
 IQR 21–27.5 22–27.8 19–25 23–28.3 18–26 19.8–27 19–23 19–26

BMI body mass index, cm centimetres, IQR inter-quartile range, SD standard deviation, yrs years

aPopulation groups and study source, by world region

 White: White women in Australia (3 studies—Australian, Greek and Italian born), Canada, Netherlands, Norway, Poland, Spain, the UK (3 studies) and the USA (mainland: 3 studies, Hawaii: 1 study)

 Black: Black women in Kenya, South Africa, the UK and the USA

 East Asian: Chinese women in Hong Kong, Malaysia and Singapore; Japanese women in Japan, Korea and the USA (mainland: 1 study, Hawaii: 1 study)

 South Asian: Malay women in Malaysia and Singapore; Indian women in India, Malaysia, Singapore and the UK

 Mestizo: Mestizo women in Chile and Mexico

 Hawaiian: Hawaiian women in USA (Hawaii: 1 study)

 Middle Eastern: Egyptian women in Egypt; Arab women in Israel; Jewish women in Iran, Israel and Turkey

bNote raw data recorded categorically by some studies and subsequently converted to an approximated numerical value

cHeight data that were measured by the original study, as opposed to self-reported

dAmong women with non-missing data. Missing data on hormone therapy were 17% overall, < 4% for black, Hawaiian, Mestizo and East Asian, 15% missing for white women and 57% for Middle Eastern. These women were included in a missing-hormone-therapy category in later regression models