Table 1.
Descriptive characteristics – Training and testing cohorts: Preterm births with and without necrotizing enterocolitis.
| Model Development | Validation | |||||||
|---|---|---|---|---|---|---|---|---|
| All n = |
No NEC n (%) |
NEC n (%) |
X2 | All n = |
No NEC n (%) |
NEC n (%) |
X2 | |
| Sample | 94,110 | 93,366 | 744 | 22,992 | 22,876 (99.50) | 116 (0.50) | ||
| Race/Ethnicity | ||||||||
| White | 25,460 (27.05) | 25,270 (27.07) | 190 (25.54) | 6,021 (26.19) | 5,992 (26.19) | 29 (25.00) | ||
| Hispanic | 47,923 (50.92) | 47,579 (50.96) | 344 (46.24) | 11,663 (50.73) | 11,608 (50.74) | 55 (47.41) | ||
| Asian | 8,509 (9.04) | 8,436 (9.04) | 73 (9.81) | 2,213 (9.63) | 2,203 (9.58) | 10 (8.62) | ||
| Black | 7,547 (8.02) | 7,448 (7.98) | 99 (13.31) | 1,883 (8.19) | 1,869 (8.17) | 14 (12.87) | ||
| Native American | 260 (0.28) | 257 (0.28) | 3 (0.40) | 53 (0.23) | 52 (9.63) | 1 (0.86) | ||
| “Other Race” | 3,116 (3.31) | 3,091 (3.31) | 25 (3.36) | 818 (3.56) | 815 (3.56) | 3 (2.59) | ||
| Unknown | 1,295 (1.38) | 1,285 (1.38) | 10 (1.34) | 30.95b | 341 (1.48) | 337 (1.47) | 4 (3.45) | 7.94 |
| Sexa | ||||||||
| Male | 42,678 (45.35) | 42,346 (45.35) | 332 (44.62) | 12,571 (54.68) | 12,506 (54.67) | 65 (56.03) | ||
| Female | 51,396 (54.61) | 50,984 (54.61) | 412 (55.38) | 0.45 | 10,412 (45.29) | 10,361 (45.29) | 51 (43.97) | 0.13 |
| Total Parenteral Nutrition | ||||||||
| Yes | 13,928 (14.80) | 13,506 (14.47) | 422 (56.72) | 5,800 (25.23) | 5,701 (24.92) | 99 (85.34) | ||
| No | 80,182 (85.20) | 79,860 (85.53) | 322 (43.28) | 1045.16b | 17,192 (74.77) | 17,175 (75.08) | 17 (14.66) | 223.39b |
| Hours/Days at Testing | ||||||||
| 12 hours – 2 days | 65,108 (69.18) | 64,786 (69.39) | 322 (43.28) | 16,158 (70.28) | 16,112 (70.43) | 46 (39.66) | ||
| 3 – 4 days | 19,310 (20.52) | 19,066 (20.42) | 244 (32.80) | 4,700 (20.44) | 4,660 (20.77) | 40 (34.48) | ||
| 5 – 6 days | 8,669 (9.21) | 8,517 (9.12) | 152 (20.43) | 1,961 (8.53) | 1,936 (8.46) | 25 (21.55) | ||
| 7 – 8 days | 1,023 (1.09) | 997 (1.07) | 26 (3.49) | 270.27b | 173 (0.75) | 168 (0.73) | 5 (4.31) | 69.60b |
| Gestational Age | ||||||||
| < 32 Weeks | 17,550 (18.65) | 16,982 (18.19) | 568 (76.34) | 4,269 (18.57) | 4,180 (18.27) | 89 (76.72) | 260.80 b | |
| 32 – 36 Weeks | 76,560 (81.35) | 76,384 (81.81) | 176 (23.66) | 1645.51b | 18,723 (81.43) | 18,696 (81.73) | 27 (23.28) | |
| Gestational Age by Birth Weight | ||||||||
| < 32 Weeks | ||||||||
| < 1500 grams | 7,828 (8.32) | 7,363 (7.89) | 465 (62.50) | 2,153 (9.36) | 2,072 (9.06) | 81 (69.83) | ||
| 1500 – 2499 grams | 4,285 (4.55) | 4,189 (4.49) | 96 (12.90) | 1,057 (4.69) | 1,049 (4.59) | 8 (6.90) | ||
| ≥ 2500 grams | 5,437 (5.78) | 5,430 (5.82) | 7 (0.94) | 1,059 (4.61) | 1,059 (4.63) | -- | ||
| 32 – 36 Weeks | ||||||||
| < 1500 grams | 1,817 (1.93) | 1,782 (1.91) | 35 (4.70) | 469 (2.04) | 464 (2.03) | 5 (4.31) | ||
| 1500 – 2499 grams | 25,290 (26.87) | 25,169 (26.96) | 121 (16.26) | 6,821 (29.67) | 6,803 (29.74) | 18 (15.52) | ||
| ≥ 2500 grams | 49,453 (52.55) | 49,433 (52.95) | 20 (2.69) | 3208.05b | 11,433 (49.73) | 11,429 (49.96) | 4 (3.45) | 522.91 |
a
36 preterm births in the “No NEC” grouping in the model development set and 9 preterm births in the “No NEC” grouping in the validation set had no sex designation.
b
p < .001