Neonatal intensive care unit occupancy rate and probability of discharge of very preterm infants

Objective: To assess the association of NICU occupancy with probability of discharge and length of stay (LOS) among infants born < 33 weeks gestational age (GA). Study design: Retrospective study of 3388 infants born 23-32 weeks GA, admitted to five Level 3/4 NICUs (2014-2018) and discharged alive. Standardized ratios of observed-to-expected number of discharges were calculated for each quintile of unit occupancy. Multivariable linear regression models were used to assess the association between occupancy and LOS. Results: At the lowest unit occupancy quintiles (Q1 and Q2), infants were 12% and 11% less likely to be discharged compared to the expected number. At the highest unit occupancy quintile (Q5), infants were 20% more likely to be discharged. Highest occupancy (Q5) was also associated with a 4.7-day (95% CI 1.7, 7.7) reduction in LOS compared Q1. Conclusion: NICU occupancy was associated with likelihood of discharge and LOS among infants born < 33 weeks GA.