Navigating the Transition: Pediatric to Adult Hospital Care for Complex Conditions

Young adults with childhood-onset complex chronic conditions (4Cs) experience substantially worse inpatient outcomes than their peers, with longer hospital stays and higher readmission rates following admission to adult hospitals.

In a retrospective cohort study of 19 915 hospitalizations among adults aged 18 to 39 years across 29 hospitals in Ontario, patients with 4Cs accounted for 6.7% of hospitalizations but 10.7% of total young-adult hospital bed-days. Compared with hospitalized young adults without 4Cs, those with 4Cs had significantly longer lengths of stay (relative ratio [RR], 1.62) and higher 30-day readmission rates (RR, 1.59).

Hospitalizations involving patients with 4Cs were also associated with higher total inpatient costs and a greater number of prescribed medications, despite lower Charlson Comorbidity Index scores. No significant differences were observed in in-hospital mortality or ICU admission rates. Notably, patients with 4Cs underwent fewer advanced imaging studies than comparators, suggesting that increased resource use was driven primarily by prolonged hospitalization and care complexity rather than higher imaging intensity.

The authors note that young adults with 4Cs represent a resource-intensive population within adult medical services and suggest they should be prioritized for targeted efforts to reduce inpatient stays and rehospitalizations. While the study does not directly examine mechanisms underlying prolonged stays or readmissions, the findings highlight limitations of traditional comorbidity indices in capturing complexity in younger adults and underscore the need for improved identification and care models for this group.

Overall, the results provide population-level evidence that childhood-onset complex chronic conditions continue to exert a substantial impact well into adulthood, reinforcing the importance of adapting adult hospital systems to better meet the needs of this growing patient population.