Table 2.
Subject and feeding characteristics according to type of first formula introduced during the first 3 months of age
| Cow’s milk–based, nonhydrolyzed | Cow’s milk–based, extensively hydrolyzed | Cow’s milk–based, partially hydrolyzed | Other formula | No formula, no cow’s milk | No formula, regular cow’s milk | |
|---|---|---|---|---|---|---|
| N = 5,523 | N = 266 | N = 274 | N = 14 | N = 2,198 | N = 31 | |
| Subject characteristics | ||||||
| Female, n (%) | 2,702 (48.9) | 127 (47.7) | 149 (54.4) | 110 (51.4) | 1,088 (49.5) | 17 (54.8) |
| HLA DR3/4, n (%) | 2,162 (39.2) | 87 (32.7) | 112 (40.9) | 100 (46.7) | 843 (38.4) | 15 (48.4) |
| HLA DR4/4, n (%) | 1,079 (19.5) | 49 (18.4) | 45 (16.4) | 28 (13.1) | 452 (20.6) | 11 (35.5) |
| HLA DR3/3, n (%) | 1,150 (20.8) | 39 (14.7) | 63 (23.0) | 48 (22.4) | 479 (21.8) | 3 (9.7) |
| First-degree relative with type 1 diabetes, n (%) | 542 (9.8) | 33 (12.4) | 64 (23.4) | 40 (18.7) | 241 (11.0) | 2 (6.5) |
| Mother with type 1 diabetes, n (%) | 221 (4.0) | 11 (4.1) | 33 (12.0) | 18 (8.4) | 53 (2.4) | 1 (3.2) |
| C-section, n (%) | 1,593 (28.9) | 52 (19.6) | 113 (41.2) | 85 (39.7) | 359 (16.4) | 3 (10.3) |
| Country, n (%) | ||||||
| U.S. | 2,580 (46.7) | 24 (9.0) | 115 (42.0) | 166 (77.6) | 731 (33.3) | 16 (51.6) |
| Finland | 1,052 (19.1) | 214 (80.5) | 4 (1.5) | 27 (12.6) | 506 (23.0) | 2 (6.5) |
| Germany | 203 (3.7) | 2 (0.8) | 151 (55.1) | 15 (7.0) | 198 (9.0) | 3 (9.7) |
| Sweden | 1,688 (30.6) | 26 (9.8) | 4 (1.5) | 6 (2.8) | 763 (34.7) | 10 (32.3) |
| Birth seasonality, n (%) | ||||||
| Spring | 1,260 (22.8) | 71 (26.7) | 62 (22.6) | 59 (27.6) | 540 (24.6) | 7 (22.6) |
| Summer | 1,369 (24.8) | 66 (24.8) | 67 (24.5) | 52 (24.3) | 577 (26.3) | 8 (25.8) |
| Fall | 1,431 (25.9) | 53 (19.9) | 74 (27.0) | 55 (25.7) | 541 (24.6) | 7 (22.6) |
| Winter | 1,463 (26.5) | 76 (28.6) | 71 (25.9) | 48 (22.4) | 540 (24.6) | 9 (29.0) |
| Feeding characteristics | ||||||
| Age at introduction of first formula (days), median (IQR) | 7 (0–28) | 0 (0–0) | 7 (0–28) | 0 (0–14) | ||
| Switching to another formula type during the first 3 months, n (%) | 961 (17.4) | 169 (63.5) | 102 (37.2) | 95 (44.4) | ||
| Duration of first formula intake (days), n (%) | ||||||
| 1–6 | 1,308 (32.3) | 156 (63.4) | 36 (18.2) | 87 (49.7) | ||
| 7–29 | 1,663 (41.1) | 81 (32.9) | 112 (56.6) | 70 (40.0) | ||
| ≥30 | 1,076 (26.6) | 9 (3.7) | 50 (25.3) | 18 (10.3) | ||
| Any breast-feeding ≥3 months, n (%) | 3,310 (60.5) | 206 (77.4) | 140 (54.5) | 152 (71.4) | 2,177 (99.1) | 23 (74.2) |
The percentages refer to the number of available subjects in the respective formula group.
IQR, interquartile range.