Table 2. Poisson regression models for neonatal mortality rate among selected Pacific Islander neonates in the 2014–2018 US birth cohort.

Model	Formula	Pearson Chi-square/DF
GA-based model	$log\left(mortality\right)={\beta }_0+{\beta }_{1}Female+{\beta }_2\sqrt{GA}$	1.007
BW-based modela	$log\left(mortality\right)={\beta }_0+{{\beta }_{1}Female+\beta }_2\sqrt{BW}$	2.799
BW-GA-based model	$log\left(mortality\right)={\beta }_0+{{\beta }_{1}Female+\beta }_2\sqrt{GA}+{\beta }_3\sqrt{BW}+{\beta }_4\sqrt{GA}\times \sqrt{BW}$	0.920

GA, gestational age. BW, birth weight. DF, degree of freedom.

^a Scaling parameter for labelled models was set to 1 due to overdispersion (Pearson Chi-square/DF>2).