Covariates Categories β SE(β) χ2 HR [95% CI] p-value
Mode of Delivery (SVD)          
CS -0.283 0.218 1.69 0.753[0.4916, 1.154] 1.90E-01
ANC (No)          
Yes         -0.608 0.229 7.05 0.544[0.3475, 0.853] 7.9e-03**
Gravidity -1          
5-Feb 0.543 0.286 3.61 1.720[0.9831, 3.011] 5.70E-02
10-Jun 0.795 0.376 4.47 2.215[1.0597, 4.629] 3.4e-02**
HIV status (Negative)          
Positive      0.575 0.285 4.08 1.776[1.0170, 3.103] 4.3e-02**
Weight of Infant       (<1600)          
[1600, 2500]    0.39 0.223 3.06 1.477[0.9543, 2.285] 8.00E-02
Multiple Pregnancy (No)          
Yes      0.117 0.202 0.34 1.124[0.7562, 1.672] 5.60E-01
RDS (No)          
Yes            1.718 0.273 39.69 5.572[3.2655, 9.509] 3.0e-10**
PNA (No)          
Yes            0.65 0.208 9.75 1.916[1.2741, 2.882] 1.8e-03**
Anemia (No)          
Yes         1.954 0.514 14.45 7.053[2.5758, 19.31] 1.4e-04**
GAvsWeight (SGA)          
AGA -0.266 0.321 0.68 0.767[0.4084, 1.439] 4.10E-01
LGA    -0.766 1.072 0.51 0.465[0.0568, 3.801] 4.70E-01
Breast Feed Initiated (Not at all)          
<1 Hr -2.214 0.444 24.91 0.109[0.0458, 0.261] 6.0e-07**
[1, 2] Hr -1.824 0.345 27.91 0.161[0.0820, 0.317] 1.3e-07**
>2 Hr -0.948 0.269 12.39 0.388[0.2287, 0.657] 4.3e-04**
Other Milk -1.766 1.07 2.72 0.171[0.0210, 1.393] 9.90E-02
       
Frailty(Gestational Age, distribution= "Gamma“) 13.91 3.1e-03**
   
Variance of Random Effect = Var(U) = θ 0.252
** Significant (P-value < 0.05) and categories in the bracket are reference categories.
Table 5: Final fitted Semiparametric Gamma frailty Model of Premature infants’ by stratification of hypothermia.