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Table 1 Characteristics of participants in the International Consortium on Mammographic Density

From: The association of age at menarche and adult height with mammographic density in the International Consortium of 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
  1. BMI body mass index, cm centimetres, IQR inter-quartile range, SD standard deviation, yrs years
  2. aPopulation groups and study source, by world region
  3.  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)
  4.  Black: Black women in Kenya, South Africa, the UK and the USA
  5.  East Asian: Chinese women in Hong Kong, Malaysia and Singapore; Japanese women in Japan, Korea and the USA (mainland: 1 study, Hawaii: 1 study)
  6.  South Asian: Malay women in Malaysia and Singapore; Indian women in India, Malaysia, Singapore and the UK
  7.  Mestizo: Mestizo women in Chile and Mexico
  8.  Hawaiian: Hawaiian women in USA (Hawaii: 1 study)
  9.  Middle Eastern: Egyptian women in Egypt; Arab women in Israel; Jewish women in Iran, Israel and Turkey
  10. bNote raw data recorded categorically by some studies and subsequently converted to an approximated numerical value
  11. cHeight data that were measured by the original study, as opposed to self-reported
  12. 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