Developmental Disabilities and Subsequent Asthma Diagnosis in Children: Diagnostic Implications from a Nationwide Population-Based Cohort Study

Background: The longitudinal risk of asthma among children with developmental disabilities (DDs) remains unclear. This study evaluated the association between DD and subsequent asthma risk. Methods: We conducted a nationwide retrospective cohort study using Taiwan’s National Health Insurance Research Database from 2009 through 2019. Children younger than 18 years with a claims-based DD diagnosis were propensity-score-matched 1:1 with children without DD. Children with asthma before the index date were excluded. Incident recorded asthma was defined using ICD-9-CM code 493.- or ICD-10-CM code J45.-; ICD-10-CM J44.- was excluded. Cox proportional hazards models estimated adjusted hazard ratios (aHRs). Prespecified subtype analyses addressed DD heterogeneity. Results: The study included 213,759 children in each cohort. The DD cohort had 43,782 recorded asthma diagnoses during 1,503,077 person-years (29.13 per 1000 person-years), compared with 30,559 diagnoses during 1,620,645 person-years among controls (18.86 per 1000 person-years). DD was associated with a higher rate of subsequent recorded asthma diagnosis (aHR, 1.70; 95% CI, 1.67–1.72), with associations present in both sexes and all age strata. Subtype-specific aHRs ranged from 1.65 for developmental delay or speech and language disorders to 1.94 for autism spectrum disorder. Exploratory post-index therapy and medication estimates were not interpreted as causal treatment effects. Conclusions: In this administrative claims cohort, a pre-existing DD diagnosis was associated with an approximately 70% higher adjusted rate of a subsequent recorded asthma diagnosis. The finding may support careful respiratory assessment when symptoms occur. Prospective studies incorporating healthcare-utilization measures, standardized asthma confirmation, and objective pulmonary testing are needed.