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.