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.