Health service utilization patterns for substance use disorders in Paraguay: real-world evidence from a specialized treatment centre in a low- and middle-income setting.

Substance use disorders (SUDs) impose a substantial and evolving burden globally, yet real-world evidence on how addiction services are utilized in low- and middle-income countries remains limited. This study examined patterns of SUD-related service utilization (ICD-10 F10-F19) in Paraguay using routinely collected data from a national specialized treatment centre in 2024. A total of 18,149 attendances were analysed. Service utilization was heavily concentrated among young adult males (83.8%), with individuals aged 20-29 years accounting for the largest proportion of attendances (42.1%). Polysubstance use (F19) predominated, representing over half of all cases (55.8%), while cocaine-, alcohol-, and cannabinoid-related disorders accounted for most of the remaining demand. Age emerged as the primary factor shaping diagnostic patterns, with polysubstance and stimulant-related disorders clustering in younger groups and alcohol-related disorders increasing with age. Notably, service utilization was highly centralized, with nearly 90% of attendances originating from metropolitan areas. These findings suggest that current service models may be misaligned with the complexity and distribution of real-world demand, characterized by polysubstance use, demographic concentration, and geographic inequities. Strengthening decentralized, gender-responsive, and age-sensitive models of care will be essential to improving access and system responsiveness in LMIC settings.