Examining the Utility of the Adaptive Behavior Scale-3rd Edition (ABAS-3) in Capturing Age-Related Changes in Daily Functioning for Neurodiverse Populations

Abstract Objective Current guidance for the assessment of cognitive decline for mild cognitive impairment or dementia lacks sufficient information for assessing neurodiverse populations (Janicki et. al, 2022), and standardized scores often have floor effects. This study investigated the utility of the Adaptive Behavior Scale-3rd Edition (ABAS-3) in characterizing age-related changes in daily functioning for individuals with autism and other intellectual and developmental disability (I/DD). Method Participants (20–76 years old) resided in community-based residential programs (CBRPs) for individuals with I/DD. Aim 1 examined mean ABAS-3 raw scores for participants with at least 1 ABAS-3 (N = 171, autism n = 115, other I/DD n = 56). Aim 2 examined changes in ABAS-3 raw scores over 2 years (N = 61, autism n = 37, other I/DD n = 24). ABAS-3 scales included “home-living” (HL), “self-care” (SC) and “health and safety” (HS). Results Aim 1 indicated variability within and across diagnostic groups, with lower performance for autistic versus other I/DD participants (p < 0.001, large effect size across all subscales). Aim 2 found varying patterns of loss, gain, and stable scores across timepoints. HL (autism loss 24.3%, gain 16.2%, stable 59.5%; I/DD loss 16.7%, gain 33.3%, stable 50.0%), SC (autism loss 29.7%, gain 16.2%, stable 54%; I/DD loss 12.5%, gain 33.3%, stable 54.2%), HS (autism loss 24.3%, gain 16.2%, stable 59.5%; I/DD loss 16.7%, gain 33.3%, stable 50.0%). Conclusions This proof-of-concept study demonstrates feasibility in characterizing ADLs of individuals with autism and I/DD living in CBRPs. Future research will assess distal ABAS-3 raw score changes to track cognitive decline in individuals with autism and other I/DD.