. Author manuscript; available in PMC: 2015 Nov 3.

Published in final edited form as: Pediatrics. 2008 Sep;122(3):479–485. doi: 10.1542/peds.2007-2313

Table 3.

Sibling pair similarities.

Outcome analyzed	r_MZ	r_DZ
BPD-28DAYS	0.87 (0.79; 0.92)	0.87 (0.80; 0.91)
BPD-36WKS	0.81 (0.70; 0.88)	0.53 (0.36; 0.67)
BPD-NICHD	0.78 (0.66; 0.86)	0.51 (0.34; 0.65)
RDS	0.71 (0.57; 0.81)	0.67 (0.54; 0.77)
PDA-INDO	0.93 (0.88; 0.95)	0.57 (0.41; 0.70)
PDA-SURG	0.99 (0.98; 1.00)	0.76 (0.66; 0.84)
# positive blood cultures	0.25 (0.02; 0.46)	0.27 (0.06; 0.45)

r = Monozygotic (MZ) or dizygotic (DZ) intra-pair correlation coefficients with 95% confidence intervals denoted in parentheses. Greater correlations for monozygotic pairs, compared with dizygotic pairs (r_MZ > r_DZ) implies sizable additive genetic effects (h²_A), which was further tested in the structural equation models (detailed in methods).