Risk factors for death during newborn and post-newborn hospitalizations among preterm infants

Objectives: To examine risk factors for mortality among preterm infants during newborn and subsequent hospitalizations, and whether they differ by race/ethnicity.

Study design: We conducted a cross-sectional analysis using the 2016 Kids Inpatient Database. Hospitalizations of preterm infants were categorized as "newborn" for birth admissions, and "post-newborn" for all others. Multivariate logistic regression was performed to calculate associations of mortality with sociodemographic factors.

Results: Of 285915 hospitalizations, there were 7827 (2.7%) deaths. During newborn hospitalizations, adjusted OR (aOR) of death equaled 1.14 (95% CI 1.09-1.20) for males, 68.73 (61.91-76.30) for <29 weeks GA, and 0.81 (0.71-0.92) for transfer. Stratified by race/ethnicity, aOR was 0.69 (0.61-0.71) for Medicaid only among black infants. During post-newborn hospitalizations, death was associated with transfer (aOR 5.02, 3.31-7.61).

Conclusions: Risk factors for death differ by hospitalization types and race/ethnicity. Analysis by hospitalization types may identify risk factors that inform public health interventions for reducing infant mortality.