Table 5.

Histopathological changes in infants with surgical NEC classified by BPD status

	Overall N = 92	Non/mild BPD N = 21	Moderate to severe BPD N=71	p-Value
Necrosis, mean (± SD) Median (IQR)	1.6 (± 1.3) 2 (0, 3)	2.2 (± 1.3) 3(1,3)	1.5 (± 1.3) 1.5 (0, 2)	0.04
Inflammation, mean (±SD) median (IQR)	1.9 (± 1.0) 2 (1,2.5)	1.9 (± 1.3) 2(1,3)	1.9 (± 0.9) 2(1,2)	0.64
Hemorrhage, mean (± SD) Median (IQR)	2.3 (± 1.2) 2(2,3)	2.5 (± 1.5) 3 (2, 4)	2.2 (± 1.1) 2(2,3)	0.34
Reparative change, mean (±SD) Median (IQR)	0.4 (± 0.5) 0(0, 1)	0.3 (± 0.5) 0(0, 1)	0.5 (± 0.5) 0(0, 1)	0.24
Necrosis, n (%)	0(0, 1)	0(0, 1)	0 (0, 0)	0.08
0	23 (29.1)	3(17.6)	20 (32.3)
< 25%	13 (16.5)	2 (11.8)	11 (17.7)
25–50%	18 (22.8)	2 (11.8)	16 (25.8)
50–75%	20 (25.3)	9 (52.9)	11 (17.7)
> 75%	5(6.3)	1 (5.9)	4(6.5)
Inflammation, n (%)				0.03
0	5 (6.3)	3(17.6)	2 (3.2)
< 25%	23 (29.1)	4(23.5)	19 (30.6)
25–50%	31 (39.2)	3(17.6)	28 (45.2)
50–75%	14 (17.7)	5 (29.4)	9 (14.5)
> 75%	6(7.6)	2 (11.8)	4(6.5)
Hemorrhage, n (%)				0.08
0	6 (7.6)	3(17.6)	3 (4.8)
< 25%	13 (16.5)	1 (5.9)	12 (19.4)
25–50%	28 (35.4)	4(23.5)	24 (38.7)
50–75%	17 (21.5)	3(17.6)	14 (22.6)
> 75%	15 (19.0)	6 (35.3)	9 (14.5)
Reparative change, n (%)	33 (41.8)	5 (29.4)	28 (45.2)	0.24

Abbreviations: BPD, bronchopulmonary dysplasia; IQR, interquartile range; NEC, necrotizing enterocolitis; SD, standard deviation.

Note: Categorical variables are presented as count (percentage). Continuous variables are presented as mean (standard deviation) and, if not normally distributed, as median with interquartile range. Continuous measures’ statistical associations with lung injury were evaluated with the Kruskal–Wallis test. Differences in categorical measures’ associations were tested using the Chi-square test when expected cell counts were adequate, otherwise Fisher-Freeman-Halton exact tests were used with low expected cell counts. Bold values are statistically significant.