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

Background: There is little consensus about how best to assess normative outcomes and objective quality of life (QoL) in adults with autism spectrum disorder (ASD). Past outcome research has found that very few adults with ASD achieve the conventional markers of adulthood – becoming employed and self-supporting, living independently, developing a network of friends, contributing to the community. Some have called for a reconceptualization of QoL for adults with ASD, but little empirical research has been conducted that can inform such a reconceptualization or identify strategies for improving the QoL of adults with ASD.

Objectives: The current study aims to construct a unified definition and conceptualization of normative outcomes and objective QoL for adults with ASD by: (1) characterizing the heterogeneity of normative outcomes and objective QoL; and (2) identifying predictors of positive normative outcomes and good objective QoL.

Methods: 180 adults with ASD between the ages of 23.72 and 60.47 (M=34.06, SD=7.99) were drawn from a longitudinal study (Adolescents and Adults with Autism). 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 intellectual disability (ID) status, age, daily living skills (Waisman Activities of Daily Living), autism symptomatology (Autism Diagnostic Interview-Revised), and executive functioning (Behavior Rating Inventory of Executive Function).

Results: Exploratory latent class analysis findings identified three discrete groups – Greater Dependence, Good Health, and Greater Independence – of adults with ASD in terms of normative outcomes and objective QoL. The Greater Independence group experienced the most favorable normative outcomes, while the Greater Dependence group experienced the worst. The Good 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 Health vs. Greater Dependence: exb(B)=1.110, p<.001; Greater Independence vs. Greater Dependence: exp(B)=1.175, p<.001)  and better executive function (Good Health vs. Greater Dependence: exp(B)=.966, p<.05; Good Health vs. Greater Independence: exp(B)=.964, p<.10) are associated with membership to outcome groups with better normative outcomes, when controlling for ID status, age, and autism symptomatology.

Conclusions: 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 is variable over time. Our 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. These findings have important implications for future research and for interventions designed to improve outcomes and QoL in adults with ASD.