Changing Referral Patterns in Paediatric Neurology: A Tertiary Outpatient Study within Brazil’s Unified Health System, 2014-2024

Introduction: The Brazilian Unified Health System (SUS) is one of the largest publicly funded health systems worldwide, yet persistent regional inequalities and structural constraints challenge equitable access to care. Understanding referral patterns for paediatric neurological conditions at tertiary centres may help inform evolving health system demands. Methods: We conducted a retrospective longitudinal study of paediatric neurology outpatient visits from 2014 to 2024 at a single tertiary referral centre within the SUS, using first visits per patient within each specialised clinic. Primary diagnoses grouped by ICD-10 code and populational-level data were extracted from medical records. Temporal trends, diagnostic overlap, and sociodemographic associations were analysed. Results: We analysed 9,000 outpatient visits. Epilepsy was the most frequent diagnosis (32.7%), followed by cerebral palsy (CP; 15.8%) and autism spectrum disorder (ASD; 11.0%). ASD increased from 3.9% in 2014 to 21.6% in 2024, whereas epilepsy declined from 39.3% to 25.2%. Over time, ASD showed the strongest increase in odds of diagnosis (OR 1.18 [1.16–1.21]; p<0.001), along with genetic counselling, sleep disorders, and headaches, while epilepsy, CP, intellectual disability, neonatal seizures, and rare diseases showed lower odds. Male sex was associated with higher odds of ASD (1.59 [1.37–1.85]; p<0.001) and ADHD (2.13 [1.73–2.61]; p<0.001). Diagnostic overlap was identified in 27.1% of patients. Conclusion: These findings suggest a change in the referral case-mix at a single tertiary paediatric neurology centre within the Brazilian SUS, characterised by a marked pre-pandemic rise in ASD referrals that stabilised at an elevated level, alongside shifts in the distribution of other neurological diagnoses.