Abstract
IMPORTANCE: Populations identified under varying definitions of developmental disability (DD) differ in notable dimensions. Understanding these crucial differences is necessary when deciding which definition to utilize for policy analysis or service planning. OBJECTIVE: To examine the distributive implications of 4 different potential definitions of DD using data from the 2023 Survey of Income and Program Participation (SIPP) and the University of Minnesota's Residential Information Systems Project (RISP). DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study of the 2023 SIPP in the US general population, including institutionalized persons, using supplemental information from 2019 RISP reports. Analyses used person-level weights, and 95% CIs were logit-transformed. The 4 definitions of DD are based on self-reported medical diagnoses of those who answered affirmatively to at least 1 of 18 disability screener questions. The narrowest definition captures cerebral palsy, intellectual disability, and/or autism diagnoses, while the broadest definition also includes epilepsy, learning disability diagnoses, and/or those identified by the SIPP learning and developmental disability screener question. MAIN OUTCOMES AND MEASURES: Outcomes include DD prevalence, utilization of long-term services and supports (LTSS), congregate residential facilities, and income support (Supplemental Security Income/Social Security Disability Insurance), self-reported employment, and impairment characteristics. RESULTS: In the study population of 2535 children and young adults aged 5 to 21 years (1285 [50.7%] males and 1250 [49.3%] females) and 9701 adults aged 22 years or older (4617 [47.6%] males and 5084 [52.4%] females), childhood and young adulthood prevalence of DD ranged from 4.17% (95% CI, 3.41%-5.09%) using the narrowest definition to 15.93% (95% CI, 14.43%-17.55%) using the broadest definition. For adults, DD prevalence varied from 1.24% (95% CI, 1.01%-1.52%) to 8.10% (95% CI, 7.48%-8.77%). Under the narrowest definition, 20.35% (95% CI, 16.67%-24.89%) of children and young adults with DD and 33.05% (95% CI, 26.87%-40.30%) of adults with DD were eligible for LTSS from a state DD agency and 0.98% (95% CI, 0.80%-1.20%) of children and young adults with DD and 9.82% (95% CI, 7.99%-11.98%) of adults with DD were estimated to be residing in a congregate residential setting. As definitions became more comprehensive, employment increased while LTSS eligibility, congregate setting placement, income support receipt (Supplemental Security Income/Social Security Disability Insurance), and functional impairment acuity decreased. CONCLUSIONS AND RELEVANCE: Results of this cross-sectional study of US children and young adults suggest that definition choice substantially affects DD prevalence estimates and the relevance of identified populations for service provision and community integration. A narrower approach may better capture individuals at greatest risk of segregation and who are most likely to utilize publicly funded DD services.