Table 4

Prediction models for postsecond day neonatal mortality, model discrimination and calibration

	Univariate	Model 1		Model 2		Model 3
Total number of newborns		13 932		13 985		14 056
Number of newborn deaths		171		172		175
Predictors	OR (95% CI)	OR (95% CI)	β	OR (95% CI)	β	OR (95% CI)	β
Birth weight, kg*
≤1.5	0.00 (0.00 to 0.02)	0.01 (0.00 to 0.09)	−4.413	0.01 (0.00 to 0.06)	−4.853
>1.5	0.08 (0.06 to 0.13)	0.16 (0.10 to 0.25)	−1.834	0.15 (0.10 to 0.23)	−1.904
Gestational age, weeks	0.81 (0.78 to 0.83)	0.91 (0.86 to 0.95)	−0.100	0.91 (0.87 to 0.95)	−0.097	0.82 (0.79 to 0.85)	−0.203
Lethargy	2.39 (1.79 to 3.18)	1.54 (1.11 to 2.14)	0.431	1.53 (1.11 to 2.12)	0.426	1.95 (1.43 to 2.66)	0.668
Cyanosis	2.30 (1.17 to 4.53)	1.41 (0.62 to 3.21)	0.340	1.39 (0.61 to 3.15)	0.326
Non-cephalic presentation	3.24 (1.79 to 5.88)	2.16 (1.12 to 4.17)	0.771	2.07 (1.08 to 3.97)	0.726	2.47 (1.32 to 4.61)	0.904
Poor suckling	4.84 (3.50 to 6.69)	2.64 (1.81 to 3.83)	0.969	2.58 (1.78 to 3.74)	0.947	3.98 (2.84 to 5.58)	1.381
Female sex	0.99 (0.74 to 1.31)	0.95 (0.69 to 1.31)	−0.049
Maternal age at urine test, years
<18	REF	REF
20–29	0.74 (0.54 to 1.01)	1.20 (0.76 to 1.88)	0.180
>29	0.81 (0.52 to 1.28)	1.20 (0.62 to 2.33)	0.186
Primigravidae	1.73 (1.29 to 2.31)	1.33 (0.85 to 2.10)	0.288
Maternal BMI <18.5 kg/m²	1.34 (1.01 to 1.79)	1.20 (0.87 to 1.66)	0.186
Betel nut chewing	0.98 (0.72 to 1.33)	1.12 (0.79 to 1.60)	0.116
Tobacco chewing	0.79 (0.48 to 1.29)	0.71 (0.40 to 1.26)	−0.344
Husband smoking	0.91 (0.68 to 1.22)	0.83 (0.59 to 1.16)	−0.192
Education level
No education	REF	REF
Class 1–4	0.91 (0.60 to 1.38)	0.91 (0.57 to 1.47)	−0.092
Class 5–9	0.68 (0.49 to 0.93)	0.79 (0.52 to 1.18)	−0.241
Class ≥10	0.53 (0.24 to 1.16)	1.13 (0.45 to 2.79)	0.118
Living standards index, above median	0.56 (0.41 to 0.75)	0.65 (0.45 to 0.93)	−0.432
Intercept			7.310		7.787		2.707
Discrimination and calibration
Area under ROC curve (95% CI)
Derivation		0.81 (0.77 to 0.84)		0.80 (0.76 to 0.84)		0.75 (0.71 to 0.80)
Validation		0.80 (0.73 to 0.88)		0.80 (0.73 to 0.87)		0.74 (0.66 to 0.81)
Hosmer Lemeshow χ2(p)
Derivation		10.61 (0.22)		6.28 (0.62)		10.25 (0.25)
Validation		11.59 (0.31)		6.56 (0.77)		10.12 (0.43)

*Birth weight modelled as a continuous linear spline with a knot at 1.5 kg. Both spline terms were included in the univariate analysis.