Characterizing Objective Quality of Life and Normative Outcomes in Adults with Autism Spectrum Disorder: An Exploratory Latent Class Analysis

Background and Purpose: The growing population of adults with autism spectrum disorder (ASD) has spurred increased interest in characterizing outcomes and quality of life (QoL) for this population. Past research has found that very few adults with ASD achieve the conventional markers of adulthood– becoming self-supporting, living independently, and developing a network of friends. However, fully characterizing the complex nature of adult life for all individuals, including individuals with ASD, necessarily goes beyond conventional markers of adulthood to include other aspects of QoL that add subtle gradation to one’s life experience. This study aims to extend the definition of QoL for adults with ASD by: (1) characterizing the heterogeneity of normative outcomes and objective QoL; and (2) identifying predictors of good normative outcomes and objective QoL.

Methods: 180 adults with ASD between the ages of 23 and 60 (M=33.5, SD=7.9) were drawn from a longitudinal study, the Adolescents and Adults with Autism Study. Three indicators of normative outcomes (employment, independent living, social engagement) and four indicators of objective QoL (physical health, quality of neighborhood, family contact, mental health issues) were assessed using a dichotomous scale and entered into an exploratory latent class analysis in order to determine groups of adults with ASD who were similar in their normative outcome and objective QoL profiles. A multinomial logistic regression then tested the association between class membership and intellectual disability (ID) status, age, daily living skills (Waisman Activities of Daily Living), autism symptomatology (Autism Diagnostic Interview-Revised), executive functioning (Behavior Rating Inventory of Executive Function), and maternal warmth.

Results: Findings identified three discrete groups–Greater Dependence, Good Physical and Mental Health, and Greater Independence–of adults with ASD in terms of normative outcome and objective QoL profiles. The Greater Independence group experienced the most favorable normative outcomes, while the Greater Dependence group experienced the worst. The Good Physical and Mental Health and Greater Independence groups experienced the most favorable objective QoL while the Greater Dependence group experienced the worst. In addition, findings indicate that better daily living skills (Good Physical and Mental Health vs. Greater Dependence: exb(B)=1.11, p<.001; Greater Independence vs. Greater Dependence: exp(B)=1.19, p<.001) and greater maternal warmth (Good Physical and Mental Health vs. Greater Independence: exp(B)=1.86, p<.05) are associated with membership to outcome groups with better normative outcomes and objective QoL, when controlling for ID status, age, autism symptomatology, and executive functioning.

Conclusions and Implications: This research proposed a broad conceptualization of normative outcomes and objective QoL that takes into account many facets of life, is long-term in nature, and may be variable over time. Findings indicate that normative outcomes and objective QoL for adults with ASD may be quite nuanced; having good normative adult outcomes may not necessarily lead to good QoL, and vice versa. Notably, there appears to be a relatively strong association between better daily living skills and membership to a group with improved normative outcomes and objective QoL. Findings have important implications for future research and for interventions designed to improve outcomes and QoL in adults with ASD.