To test the hypothesis that newborn infants cared for in hospitals with greater utilization of neonatal intensive care experienced fewer postdischarge adverse events.

We developed 3 retrospective population-based cohorts of Texas Medicaid insured singletons born in 2010-2014 (very low birth weight [VLBW n = 11 139], late preterm [n = 57 509], and non-preterm [n = 664 447]) who received care in higher volume hospitals with level III/IV neonatal intensive care units (NICUs). Measures of NICU care were hospital-level risk adjusted NICU admission rates, special care days (days of nonroutine care) per infant, and the percent of intensive (highest billable care code) special care days. The units of analysis were hospitals (n = 80) and the primary outcome was an adverse event, (defined as admission, emergency department visit, or death) within 30 days postdischarge.

Higher use of NICU care at a hospital level was not associated with lower postdischarge 30-day adverse event. Infants cared for in hospitals with above vs below median special care day rates experienced slightly higher postdischarge adverse event per 100 infants (VLBW: 14.01 [95% CI 12.74-15.27] vs 11.84 [10.52-13.16], P < .05; late preterm: 7.33 [6.68-7.97] vs 6.28 [5.87-6.69], P < .01; non-preterm: 4.47 [4.17-4.76] vs 3.97 [3.75-4.18], P < .01). Weak positive associations (Pearson correlations of 0.31-0.37, P < .01) were observed for adverse event with special care days; in no instance was a negative association observed between NICU utilization and adverse event.

Higher utilization of NICU care was not associated with lower rates of short-term events suggesting that there may be opportunities to safely decrease admission rates and length of NICU stays.