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. 2020 Apr 6;4(1):e000635. doi: 10.1136/bmjpo-2020-000635

Table 3.

Baseline characteristics of study cohort by exposure variable: maternal ethnicity

Characteristic Total European* East Asian Southeast Asian South Asian West Asian /North African African and Caribbean Latin American Indigenous Mixed
N 1851 1214 105 65 169 43 79 57 6 113
Patient-level characteristics
Female sex 908 (49.1) 591 (48.7) 58 (55.2) 39 (60.0) 71 (42.0) 17 (39.5) 42 (53.2) 31 (54.4) 2 (33.3) 57 (50.4)
Child's age, months
 12–15 597 (32.3) 400 (33.0) 26 (24.8) 18 (27.7) 46 (27.2) 20 (46.5) 26 (32.9) 20 (35.1) 4 (66.7) 37 (32.7)
 15–18 298 (16.1) 196 (16.1) 17 (16.2) 8 (12.3) 19 (11.2) 7 (16.3) 19 (24.1) 6 (10.5) 0 (0) 26 (23.0)
 18–24 410 (22.2) 263 (21.7) 26 (24.8) 18 (27.7) 45 (26.6) 8 (18.6) 16 (20.3) 14 (24.6) 1 (16.7) 19 (16.8)
 24–38 546 (29.5) 355 (29.2) 36 (34.3) 21 (32.3) 59 (34.9) 8 (18.6) 18 (22.8) 17 (29.8) 1 (16.7) 31 (27.4)
Gestational age, weeks
 32–36 211 (11.4) 123 (10.1) 14 (13.3) 4 (6.2) 33 (19.5) 5 (11.6) 11 (13.9) 6 (10.5) 1 (16.7) 14 (12.4)
 ≥37 1392 (75.2) 932 (76.8) 76 (72.4) 41 (63.1) 117 (69.2) 25 (58.2) 63 (79.8) 46 (80.7) 5 (83.3) 87 (77.0)
 Missing 248 (13.4) 159 (13.1) 15 (14.3) 20 (30.8) 19 (11.2) 13 (30.2) 5 (6.3) 5 (8.8) 0 (0) 12 (10.6)
Birth weight, kg
 <2.5 195 (10.5) 109 (9.0) 12 (11.4) 5 (7.7) 26 (15.4) 5 (11.6) 18 (22.8) 9 (15.8) 1 (16.7) 10 (8.9)
 ≥2.5 1525 (82.4) 1028 (84.7) 82 (78.1) 53 (81.5) 127 (75.2) 34 (79.1) 59 (74.7) 41 (71.9) 5 (83.3) 96 (84.9)
 Missing 131 (7.1) 77 (6.3) 11 (10.5) 7 (10.8) 16 (9.5) 4 (9.3) 2 (2.5) 7 (12.3) 0 (0) 7 (6.2)
zBMI
 Underweight (z<−2) 48 (2.6) 24 (2.0) 3 (2.9) 2 (3.0) 9 (5.3) 0 (0) 2 (2.5) 2 (3.5) 0 (0) 6 (5.3)
 Normal weight (−2≤z≤1) 1393 (75.3) 908 (74.8) 80 (76.2) 54 (83.1) 130 (76.9) 35 (81.4) 57 (72.2) 40 (70.2) 6 (100) 83 (73.5)
 At-risk-of-overweight (1<z ≤ 2) 277 (15.0) 197 (16.2) 12 (11.4) 5 (7.7) 16 (9.5) 7 (16.3) 15 (19.0) 10 (17.5) 0 (0) 15 (13.3)
 Overweight (2<z≤ 3) 64 (3.5) 43 (3.5) 5 (4.8) 2 (3.1) 4 (2.4) 0 (0) 3 (3.8) 2 (3.5) 0 (0) 5 (4.4)
 Obese (z>3) 11 (0.6) 6 (0.5) 1 (1.0) 0 (0) 2 (1.2) 0 (0) 1 (1.3) 1 (1.8) 0 (0) 0 (0)
 Missing 58 (3.1) 36 (3.0) 4 (3.8) 2 (3.1) 8 (4.7) 1 (2.3) 1 (1.3) 2 (3.5) 0 (0) 4 (3.5)
Maternal education
 Post-Secondary 1665 (90.0) 1117 (92.0) 102 (97.1) 61 (93.9) 141 (83.4) 33 (76.7) 57 (72.2) 48 (84.2) 6 (100) 100 (88.5)
 No post-Secondary 149 (8.0) 76 (6.3) 3 (2.9) 4 (6.1) 20 (11.8) 8 (18.6) 20 (25.3) 7 (12.3) 0 (0) 11 (9.7)
 Missing 37 (2.0) 21 (1.7) 0 (0) 0 (0) 8 (4.7) 2 (4.7) 2 (2.5) 2 (3.5) 0 (0) 2 (1.8)
Family income (CAN $)
 < $30 000 106 (5.7) 24 (2.0) 2 (1.9) 7 (10.8) 29 (17.2) 6 (14.0) 20 (25.3) 10 (17.5) 1 (16.7) 7 (6.2)
 $30 000 to $79 999 275 (14.9) 120 (9.9) 14 (13.3) 17 (26.2) 52 (30.8) 10 (23.3) 20 (25.3) 17 (29.8) 1 (16.7) 24 (21.2)
 $80 000+ 1187 (64.1) 880 (72.5) 74 (70.5) 27 (41.5) 66 (39.1) 20 (46.5) 26 (32.9) 24 (42.1) 3 (50.0) 67 (59.3)
 Missing 283 (15.3) 190 (15.7) 15 (14.3) 14 (21.5) 22 (13.0) 7 (16.3) 13 (16.5) 6 (10.5) 1 (16.7) 15 (13.3)
Family immigration status
 Non-immigrant (Cdn born) 943 (50.9) 809 (66.6) 24 (22.9) 10 (15.4) 23 (13.6) 10 (23.3) 17 (21.5) 6 (10.5) 5 (83.3) 39 (34.5)
 Immigrant, industrialised 306 (16.5) 239 (19.7) 29 (27.6) 1 (1.5) 8 (4.7) 6 (14.0) 1 (1.3) 1 (1.8) 0 (0) 21 (18.6)
 Immigrant, non-industrialised 551 (29.8) 133 (11.0) 49 (46.7) 53 (81.5) 133 (78.7) 23 (53.5) 61 (77.2) 49 (86.0) 1 (16.7) 49 (43.4)
 Missing 51 (2.8) 33 (2.7) 3 (2.9) 1 (1.5) 5 (3.0) 4 (9.3) 0 (0) 1 (1.8) 0 (0) 4 (3.5)
Laboratory characteristics
CRP level
 ≤1.0 mg/L 1532 (82.8) 990 (81.6) 89 (84.8) 55 (84.6) 145 (85.8) 36 (79.1) 62 (78.5) 51 (89.5) 5 (83.3) 99 (87.6)
 >1.0 to <10.0 mg/L 311 (16.8) 218 (18.0) 16 (15.2) 10 (15.4) 23 (13.6) 7 (16.3) 17 (21.5) 6 (10.5) 1 (16.70 13 (11.5)
 Missing 8 (0.4) 6 (0.5) 0 (0) 0 (0) 1 (0.6) 0 (0) 0 (0) 0 (0) 0 (0) 1 (0.9)
Serum ferritin (µg/L) 23 (16 to 35) 23 (16 to 34) 28 (19 to 41) 31 (19 to 46) 22 (14 to 33) 22 (13 to 39) 27 (17 to 45) 22 (17 to 30) 18 (12 to 25) 22 (14 to 36)
Haemoglobin (g/L) 119 (114 to 124) 119 (114 to 123) 122 (116 to 126) 119 (113 to 126) 119 (113 to 126) 117 (116 to 124) 117 (110 to 123) 120 (117 to 125) 123 (110 to 124) 121 (114 to 127)
 Missing 284 (15.3) 198 (16.3) 19 (18.1) 12 (18.5) 13 (7.7) 6 (14.0) 10 (12.7) 13 (22.8) 0 (0) 13 (11.5)
Iron deficiency, yes 226 (12.2) 139 (11.5) 5 (4.8) 5 (7.7) 34 (20.1) 9 (20.9) 7 (8.9) 7 (12.3) 1 (16.7) 19 (16.8)
Iron deficiency anaemia, yes 66 (3.8) 39 (3.2) 1 (1.0) 1 (1.5) 8 (4.7) 1 (2.3) 5 (6.3) 2 (3.5) 1 (16.7) 8 (7.1)
 Missing 284 (15.3) 198 (16.3) 19 (18.1) 12 (18.5) 13 (7.7) 6 (13.9) 10 (12.7) 13 (22.8) 0 (0) 13 (11.5)
Infant feeding practices
Breastfeeding duration
 ≤12 months 960 (51.9) 634 (52.2) 56 (53.3) 39 (60.0) 90 (53.3) 23 (52.5) 43 (54.4) 26 (45.6) 4 (66.6) 45 (39.8)
 >12 months 789 (42.6) 511 (42.1) 47 (44.8) 21 (32.3) 71 (42.0) 19 (44.2) 30 (38.0) 27 (47.4) 1 (16.7) 62 (54.9)
 Missing 102 (5.5) 69 (5.7) 2 (1.9) 5 (7.7) 8 (4.7) 1 (2.3) 6 (7.6) 4 (7.0) 1 (16.7) 6 (5.3)
Cow’s milk consumption
 ≤2 cups (500 mL) 1306 (70.6) 874 (72.0) 79 (75.2) 39 (60.0) 106 (62.7) 30 (69.8) 49 (62.0) 38 (66.7) 4 (66.7) 87 (77.0)
 >2 cups (500 mL) 503 (27.2) 316 (26.0) 24 (22.9) 23 (35.4) 59 (34.9) 11 (25.6) 28 (35.4) 19 (33.3) 2 (33.3) 21 (18.6)
 Missing 42 (2.2) 24 (2.0) 2 (1.9) 3 (4.6) 4 (2.4) 2 (4.7) 2 (2.5) 0 (0.0) 0 (0.0) 5 (4.4)
Bottle use duration
 ≤15 months 1127 (60.9) 772 (63.6) 63 (60.0) 31 (47.7) 80 (47.3) 28 (65.1) 43 (54.4) 32 (56.1) 4 (66.7) 74 (65.5)
 >15 months 538 (29.1) 317 (26.1) 26 (24.8) 25 (38.5) 75 (44.4) 13 (30.2) 29 (36.7) 22 (38.6) 2 (33.3) 29 (25.7)
 Missing 186 (10.0) 125 (10.3) 16 (15.2) 9 (13.9) 14 (8.2) 2 (4.7) 7 (8.9) 3 (5.3) 0 (0) 10 (8.9)
Meat consumption
 Yes 1777 (96.0) 1175 (96.8) 105 (100.0) 61 (93.9) 150 (88.8) 42 (97.7) 74 (93.7) 56 (98.3) 6 (100.0) 108 (95.6)
 No 69 (3.7) 36 (3.0) 0 (0.0) 3 (4.6) 18 (10.7) 1 (2.3) 5 (6.3) 1 (1.8) 0 (0.0) 5 (4.4)
 Missing 5 (0.3) 3 (0.2) 0 (0.0) 1 (1.5) 1 (0.6) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0)
Infant formula use
 Yes 261 (14.1) 157 (12.9) 12 (11.4) 13 (20.0) 20 (11.8) 12 (27.9) 20 (25.3) 7 (12.3) 2 (33.3) 18 (15.9)
 No 1368 (73.9) 928 (76.4) 80 (76.2) 40 (61.5) 123 (72.8) 24 (55.8) 49 (62.0) 42 (73.7) 4 (66.7) 78 (69.0)
 Missing 222 (12.0) 129 (10.6) 13 (12.4) 12 (18.5) 26 (15.4) 7 (16.3) 10 (12.7) 8 (14.0) 0 (0.0) 17 (15.0)

Data regarding baseline characteristics are presented as n (%) or median (IQR).

CRP, C reactive protein; zBMI, body mass index z score.