The increasing proportion of adult discharges at children's hospitals, 2004-2019.

Significant medical advances now enable individuals with pediatric illnesses to survive into adulthood. Finding medical homes for these individuals often remains challenging. We utilized the Pediatric Health Information System to measure the variation in and growth of admissions to children's hospitals, stratified by age and payor from 2004 to 2019. We identified 8,097,081 patient encounters from 30 hospitals. Compared to children, adults discharged at children's hospitals are more likely to have a complex chronic condition, have a higher median cost, and have a longer median length of stay. Hospital-level adult discharges ranged from 1.9% to 10.1% (median 4.1%; interquartile range: 2.8%-5.4%). Significantly higher increases were seen in each adult age subgroup (18-20, 21-25, and >25 years old) compared to the pediatric age group (p < .001). The number of adults discharged from children's hospitals is increasing faster than children, impacting children's hospitals and the populations they serve.