Table 3.

Risk factors for mortality in cases of HLHS or hypoplastic left ventricle with additional CHD born 1998–2012.

Risk factors	N (%)	Age 1 year Kaplan-Meier survival estimate	Hazard ratio (95% CI)	P-value
Gestational age				0.007
Preterm (<37 weeks)	50 (14.5)	52.0 (37.4, 64.7)	1.77 (1.21, 2.57)
Term (37–41 weeks)	270 (78.3)	67.5 (61.6 (72.8)	1 (reference category)
Post-term (≥42 weeks)	12 (3.5)	91.7 (53.9, 98.8)	0.72 (0.29, 1.76)
Missing	13 (3.8)
Birth weight				0.005
Low (<2,500 g)	63 (18.3)	57.1 (44.0, 68.3)	1.51 (1.09, 2.23)
Average (2,500–3,999 g)	240 (70.1)	66.7 (60.3, 72.2)	1 (reference category)
High (≥4,000 g)	32 (9.3)	81.3 (63.0, 91.1)	0.50 (0.25, 0.98)
Missing	8 (2.3)
Maternal age				0.17
<20	44 (13.0)	54.6 (8.8, 67.8)	1.42 (0.92, 2.19)
20–34	225 (65.5)	68.9 (62.4, 74.5)	1 (reference category)
≥35	61 (17.7)	63.9 (50.6, 74.6)	1.31 (0.88, 1.93)
Missing	13 (3.8)
Sex
Female	139 (40.3)	59.7 (51.1, 67.3)	1 (reference category)	0.01
Male	204 (59.7)	71.1 (64.3, 76.8)	0.67 (0.50, 0.91)
Socioeconomic deprivation (IMD)				0.65
Least deprived Q1	38 (11.0)	73.7 (56.6, 94.9)	1 (reference category)
Q2	38 (11.3)	55.3 (38.3, 69.3)	1.57 (82.9, 2.97)
Q3	43 (12.5)	69.8 (53.7, 81.2)	1.06 (54.9, 2.04)
Q4	61 (17.7)	67.2 (53.9, 77.5)	1.18 (0.65, 2.17)
Most deprived Q5	93 (27.0)	67.4 (56.8, 76.0)	1.20 (0.68, 2.12)
Missing	71 (20.6)
Plurality				0.82
Singleton	320 (93.3)	66.3 (60.8, 71.1)	1 (reference category)
Multiple	15 (4.3)	66.7 (37.5, 84.6)	1.09 (0.51, 2.33)
Missing	8 (2.0)
Extra-cardiac anomalies				0.86
Isolated	297 (86.7)	67.3 (61.7, 72.4)	1 (reference category)
Structural ECA	27 (7.9)	55.6 (35.2, 71.8)	1.25 (0.72, 2.17)
Chromosomal ECA	19 (5.5)	68.4 (42.8, 84.4)	1.23 (0.67, 2.27)

HLHS, Hypoplastic Left Heart Syndrome, ECA, Extra-Cardiac Anomaly, IMD, Index of Multiple Deprivation.