Real‐World Effectiveness for Sublingual Allergen Immunotherapy Among School‐Aged Children and Adolescents

ABSTRACT Background Sublingual allergen immunotherapy (SLIT) is a safe and effective treatment of allergic rhinitis, and its use has been increasing in recent years. Although several randomized and observational studies showed the effectiveness of SLIT among adults and children aged > 12 years, its extent remains unclear in nationwide routine healthcare settings for school‐aged children. Methods We conducted a propensity score (PS)‐matched cohort study using a nationwide administrative database. Data from 13,449 individuals who received SLIT for house dust mites between 2015 and 2021 were extracted and matched with data from 1,732,961 individuals who did not. The PS‐matching procedure created 10,985 pairs and followed them for three years, totaling 812,795 person‐months. Then, we compared healthcare costs, resource use, and prescriptions between the SLIT and control groups over the three years. Results The introduction of SLIT was associated with an 8.9% reduction in antibiotic use (95% CI, 12.0% to 34.7%) and a 65.2% reduction in hospitalizations (95% CI, 52.8% to 74.4%), as well as a 44.1% increase in health resource utilization (95% CI, 40.7% to 47.6%), with minimal impact on overall healthcare costs (+8.9% [95% CI, −12.0% to +34.7%]) over the three‐year follow‐up period. Similar findings were observed in event‐study design and intention‐to‐treat analyses, as well as in age‐stratified analyses (ages 5–10 years and 11–19 years). Conclusions The introduction of SLIT for house dust mites was associated with a reduction in antibiotic prescriptions and hospitalizations among children aged 5–19 years with minimal impact on healthcare costs, demonstrating sustained benefits over three years.