Table 2

Stepwise forward multiple regression analysis showing effect of five independent variables on mortality in very low birthweight infants and resulting equation to predict mortality

VariableLogistic β slopesStandard errorRegression coefficientP value
Birthweight−0.83870.1768−0.2231< 0.0001
Respiratory distress syndrome0.70510.13840.2411< 0.0001
Apgar score at 5 minutes−0.55300.1613−0.15390.0006
Artificial ventilation0.53490.1930−0.11740.0056
Base excess at admission0.36840.13210.11850.0053
Constant−0.36901.12020.7419
Equation to predict mortality:
Pr(mortality) = 1 / (1 + exp (−(− 0.37− 0.84 BW + 0.71 RDS − 0.55 APGAR + 0.53 VENT + 0.37 BE)))
  • Pr = probability; BW = birthweight category; RDS = respiratory distress syndrome category; VENT = ventilatory support category; BE = base excess category (as defined in table 1).