Transition of Rare and/or Complex Conditions From Paediatric to Adult Care: Use of the ITG Form and Outcome Analysis

Introduction Health care transition (HCT) is a coordinated pathway supporting the progression of young adults into adult‐oriented health services. A structured pathway is essential to ensure continuity for patients with complex and chronic conditions. This study analyzes the transition model implemented at the City of Health and Science University Hospital of Turin (Italy), a tertiary hospital providing both paediatric and adult care. The study involves a cohort of patients with a wide spectrum of rare and/or complex chronic conditions, focussing on factors influencing successful transitions and sustained patient adherence to follow‐up. Methods A retrospective cohort study was conducted on 215 Italian patients (109 males and 106 females) who transferred from paediatric to adult care between 2015 and 2019. The mean age at transfer was 20.9 years (SD ± 5.8). Data were collected from medical records and the ITG (Interdisciplinary Transition Group) forms, which assess clinical and disability complexity indicators and adverse social determinants of health. Primary outcomes included nonattendance at the first two visits in adult care, long‐term continuity of care and post‐transfer clinical stability assessed through the proxy of post‐to‐pre transfer visit ratio. Logistic regression models were employed to identify factors associated with these outcomes. Results Overall, 87.0% of patients attended the initial two adult visits, with retention remaining 83.7% at 2 years and 41.4% at 4 years. Transfer before the age of 20 was significantly associated with enhanced clinical stability ( p = 0.002). Patients with at least one complexity indicator identified in the ITG form exhibited a post‐to‐pre transfer visits ratio ( p = 0.007), indicating increased intensity of outpatient attendance. Conclusions These findings underscore the need for targeted strategies to facilitate successful transitions, particularly for patients screened for clinical and social risk factors. The ITG form has proven effective in identifying individuals requiring intensive follow‐up, thereby supporting the optimization of transition pathways and long‐term patient outcomes in Italy.