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Journal ArticleDOI

Assessing general and autism-relevant quality of life in autistic adults: A psychometric investigation using item response theory

19 Apr 2021-Autism Research (John Wiley & Sons, Ltd)-Vol. 14, Iss: 8, pp 1633-1644
TL;DR: In this article, the authors examined the measurement properties of the autism spectrum quality of life form (ASQoL), a new measure of QoL designed specifically for autistic people, using data from 700 autistic adults recruited from the Simons Foundation's SPARK cohort.
Abstract: Although many interventions and services for autistic people have the ultimate goal of improving quality of life (QoL), there is relatively little research on how best to assess this construct in the autistic population, and existing scales designed for non-autistic individuals may not assess all meaningful facets of QoL in the autistic population. To address this need, the autism spectrum QoL form (ASQoL) was recently developed as a measure of the autism-relevant quality of life. However, the psychometrics of the ASQoL have not been examined beyond the authors' initial validation study, and important properties such as measurement invariance/differential item functioning (DIF) have not yet been tested. Using data from 700 autistic adults recruited from the Simons Foundation's SPARK cohort, the current study sought to perform a comprehensive independent psychometric evaluation of the ASQoL using item response theory, comparing its performance to a newly-proposed brief measure of general QoL (the WHOQOL-4). Our models revealed substantial DIF by sex and gender in the ASQoL, which caused ASQoL scores to grossly underestimate the self-reported QoL of autistic women. Based on a comparison of latent variable means, we demonstrated that observed sex/gender differences in manifest ASQoL scores were the result of statistical artifacts, a claim that was further supported by the lack of significant group differences on the sex/gender-invariant WHOQOL-4. Our findings indicate that the ASQoL composite score is psychometrically problematic in its current form, and substantial revisions may be necessary before valid and meaningful inferences can be made regarding autism-relevant aspects of QoL. LAY SUMMARY: Quality of life (QoL) is an extremely important outcome for autistic people, but many of the tools that are used to measure it does not take into account how QoL may be different for autistic people. Using data from 700 autistic adults, we examined the measurement properties of the autism spectrum quality of life form (ASQoL), a new measure of QoL designed specifically for autistic people. Our results indicate that the ASQoL shows a pronounced sex/gender bias, which causes it to underestimate QoL in autistic women. This bias needs to be eliminated before the ASQoL can be successfully used to measure QoL in the autistic population.
Citations
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Journal ArticleDOI
TL;DR: Williams et al. as mentioned in this paper conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 cognitively able autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in large international psychological study.
Abstract: Background Alexithymia, a personality trait characterized by difficulties interpreting emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies several cognitive and emotional differences previously attributed to autism. Although questionnaires such as the 20-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have investigated the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults. Methods This study is a revised version of a previous article that was retracted due to copyright concerns (Williams and Gotham in Mol Autism 12:1-40). We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 cognitively able autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study. The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to generate a subset of the items that were strong indicators of a "general alexithymia" factor. Correlations between alexithymia and other clinical outcomes were used to assess the nomological validity of the new alexithymia score in the SPARK sample. Results The TAS-20 did not exhibit adequate model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an 8-item general alexithymia factor score (GAFS-8, with "TAS" no longer referenced due to copyright) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that GAFS-8 scores, as derived from the TAS-20, meaningfully predict autistic trait levels, repetitive behaviors, and depression symptoms, even after controlling for trait neuroticism. The GAFS-8 also presented no meaningful decrement in nomological validity over the full TAS-20 in autistic participants. Limitations Limitations of the current study include a sample of autistic adults that was majority female, later diagnosed, and well educated; clinical and control groups drawn from different studies with variable measures; only 16 of the TAS-20 items being administered to the non-autistic sample; and an inability to test several other important psychometric characteristics of the GAFS-8, including sensitivity to change and I-DIF across multiple administrations. Conclusions These results indicate the potential of the GAFS-8 to robustly measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced GAFS-8 latent trait scores in research applications (available at https://asdmeasures.shinyapps.io/alexithymia ).

13 citations

Journal ArticleDOI
11 Apr 2022-Autism
TL;DR: In this article , a participatory team of autistic and non-autistic researchers examined whether learning one is autistic at a younger age is associated with heightened well-being and Autism-Specific Quality of Life among autistic university students.
Abstract: Many autistic people do not learn they are autistic until adulthood. Parents may wait to tell a child they are autistic until they feel the child is “ready.” In this study, a participatory team of autistic and non-autistic researchers examined whether learning one is autistic at a younger age is associated with heightened well-being and Autism-Specific Quality of Life among autistic university students. Autistic students (n = 78) completed an online survey. They shared when and how they learned they were autistic, how they felt about autism when first learning they are autistic and now, and when they would tell autistic children about their autism. Learning one is autistic earlier was associated with heightened quality of life and well-being in adulthood. However, learning one is autistic at an older age was associated with more positive emotions about autism when first learning one is autistic. Participants expressed both positive and negative emotions about autism and highlighted contextual factors to consider when telling a child about autism. Findings suggest that telling a child that they are autistic at a younger age empowers them by providing access to support and a foundation for self-understanding that helps them thrive in adulthood. Lay abstract People learn they are autistic at different ages. We wanted to know if telling kids they are autistic earlier helps them feel better about their lives when they grow up. We are a team of autistic and non-autistic students and professors. Seventy-eight autistic university students did our online survey. They shared how they found out they were autistic and how they felt about being autistic. They also shared how they feel about their lives now. Around the same number of students learned they were autistic from doctors and parents. Students who learned they were autistic when they were younger felt happier about their lives than people who learned they were autistic when they were older. Students who learned they were autistic when they were older felt happier about being autistic when they first found out than people who did not have to wait as long. Our study shows that it is probably best to tell people they are autistic as soon as possible. The students who did our study did not think it was a good idea to wait until children are adults to tell them they are autistic. They said that parents should tell their children they are autistic in ways that help them understand and feel good about who they are.

12 citations

Journal ArticleDOI
TL;DR: Both individual symptoms and total symptom burden were related to higher levels of depression, anxiety, and autistic traits, along with lower quality of life in autistic young adults, particularly women.
Abstract: Somatic symptoms are the most common cause of outpatient medical visits in the general population, yet their presence and severity in individuals on the autism spectrum has rarely been studied. We sought to assess the prevalence, impact, and clinical correlates of 14 commonly reported somatic symptoms in a sample of 290 transition‐aged autistic young adults (mean [SD] age: 23.10 [2.38] years, range 18–26; 76.7% diagnosed with autism before age 18) recruited from the Simons Foundation SPARK participant pool. A modified version of the Patient Health Questionnaire–15 was used to assess somatic symptom prevalence/impact, along with measures of depression, anxiety, autistic traits, and quality of life. Somatic symptom burden was much higher in autistic young adults than previously reported in the general population. The most commonly reported current symptoms were fatigue (72.8%), sleep problems (69.0%), and menstrual problems (61.4% of females). Moderate or severe symptom levels were reported by 53.9% of females and 18.75% of males in our cohort, with the odds of females endorsing any given symptom being 2–4 times greater than males. Both individual symptoms and total symptom burden were related to higher levels of depression, anxiety, and autistic traits, along with lower quality of life. Despite little research on this topic previously, somatic symptoms are highly prevalent in autistic young adults, particularly women. Future research is needed to investigate links between somatic symptoms, medical and psychiatric morbidity, and health care utilization in the autistic population.

10 citations

Journal ArticleDOI
01 Apr 2022-Autism
TL;DR: Even after taking into account background, depression, and anxiety, social support was important for individuals' QoL, and improving social support may have a significant impact on the quality of life of older autistic adults.
Abstract: Social support has a positive impact on quality of life (QoL) in neurotypical older adults and young autistic adults, but the association for older autistic adults is unclear. Autistic adults (n = 388; mean age = 40–83 years) were recruited via Simons Powering Autism Research for Knowledge (SPARK) Research Match. Participants completed questionnaires online querying demographic information, depression, and anxiety symptomatology, QoL (physical, psychological, social, environmental, and autism-specific) and social support (instrumental, subjective, and social interactions). Regression analyses examined whether different aspects of social support contributed to models explaining each domain of QoL. Models explaining QoL were significant. Subjective social support significantly contributed to the models for all aspects of QoL; social interactions contributed to the models for Physical and Psychological QoL, whereas instrumental support contributed to models for social, environmental and autism-specific QoL. Social support is an important contributor to the QoL of middle-aged and older autistic adults, after accounting for demographic factors and depression. Further studies are required to understand whether age-related changes in social support and QoL are the same for autistic as non-autistic older adults in order to identify and implement appropriate support. Lay abstract Social support can take many forms, such as practical help, time spent socially with others, or the satisfaction with personal relationships. Social support is known to affect quality of life (QoL) in both non-autistic older and autistic young adults. QoL reflects how satisfied an individual is with their life either overall or in a certain area. We know little about middle-aged and older autistic adults’ experiences of social support or QoL. In this study, 388 adults aged 40–83 years old, completed online questionnaires asking about background such as age and sex, depression and anxiety symptoms, QoL (physical, psychological, social, environmental, and autism-specific), and different types of social support. Even after taking into account background, depression, and anxiety, social support was important for individuals’ QoL. To our knowledge this is the first paper to examine the relationship between social support and QoL in middle-aged and older autistic adults. Improving social support may have a significant impact on the QoL of older autistic adults. Future studies should examine whether age-related changes in social support (size, content, and arrangement of social networks) that are common in non-autistic aging, also occur among older autistic adults.

6 citations

Journal ArticleDOI
11 Apr 2022-Autism
TL;DR: In this article , a new way to score the Patient-Reported Outcomes Measurement Information System Global-10 scale and generate a "general quality of life" score specific to autistic adults was proposed, showing very little measurement error and relating in expected ways to similar constructs, such as physical health and emotional distress.
Abstract: Quality of Life an outcome that both researchers and autistic advocates agree is extremely important to consider when implementing services, interventions, and supports for autistic people. However, there has been little research on the topic of how quality of life can best be measured in autistic people or whether existing quality of life questionnaires are appropriate for use in the autistic population. This study aimed to validate an established quality of life measure, the Patient-Reported Outcomes Measurement Information System Global-10, in a large sample of autistic adults recruited online. We created a new way to score the Patient-Reported Outcomes Measurement Information System Global-10 scale and generate a "General quality of life" score specific to autistic adults. This new score performed very well in this sample, showing very little measurement error and relating in expected ways to similar constructs, such as physical health and emotional distress. Exploratory analyses found that lower quality of life was associated with female sex and self-identification as a sexual or gender minority (i.e. LGBTQ + identity). These findings suggest that the new Patient-Reported Outcomes Measurement Information System Global-10 quality of life score is a reliable and valid measure of quality of life in autistic adults, although additional studies are necessary to further explore its measurement properties in other subsets of the autistic population, such as individuals with intellectual disabilities. This measure is freely available for use as an outcome in both research and clinical practice, and an online score calculator is available to support the use of this measure in real-world applications.

5 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a different approach to problems of multiple significance testing is presented, which calls for controlling the expected proportion of falsely rejected hypotheses -the false discovery rate, which is equivalent to the FWER when all hypotheses are true but is smaller otherwise.
Abstract: SUMMARY The common approach to the multiplicity problem calls for controlling the familywise error rate (FWER). This approach, though, has faults, and we point out a few. A different approach to problems of multiple significance testing is presented. It calls for controlling the expected proportion of falsely rejected hypotheses -the false discovery rate. This error rate is equivalent to the FWER when all hypotheses are true but is smaller otherwise. Therefore, in problems where the control of the false discovery rate rather than that of the FWER is desired, there is potential for a gain in power. A simple sequential Bonferronitype procedure is proved to control the false discovery rate for independent test statistics, and a simulation study shows that the gain in power is substantial. The use of the new procedure and the appropriateness of the criterion are illustrated with examples.

83,420 citations

Journal ArticleDOI
TL;DR: The aims behind the development of the lavaan package are explained, an overview of its most important features are given, and some examples to illustrate how lavaan works in practice are provided.
Abstract: Structural equation modeling (SEM) is a vast field and widely used by many applied researchers in the social and behavioral sciences. Over the years, many software packages for structural equation modeling have been developed, both free and commercial. However, perhaps the best state-of-the-art software packages in this field are still closed-source and/or commercial. The R package lavaan has been developed to provide applied researchers, teachers, and statisticians, a free, fully open-source, but commercial-quality package for latent variable modeling. This paper explains the aims behind the development of the package, gives an overview of its most important features, and provides some examples to illustrate how lavaan works in practice.

14,401 citations

Journal ArticleDOI
TL;DR: The establishment of measurement invariance across groups is a logical prerequisite to conducting substantive cross-group comparisons (e.g., tests of group mean differences, invariance of structura, etc.).
Abstract: The establishment of measurement invariance across groups is a logical prerequisite to conducting substantive cross-group comparisons (e.g., tests of group mean differences, invariance of structura...

6,086 citations

Journal ArticleDOI
TL;DR: Hu and Bentler as mentioned in this paper proposed a more rigorous approach to evaluating decision rules based on GOF indexes and, on this basis, proposed new and more stringent cutoff values for many indexes.
Abstract: Goodness-of-fit (GOF) indexes provide "rules of thumb"—recommended cutoff values for assessing fit in structural equation modeling. Hu and Bentler (1999) proposed a more rigorous approach to evaluating decision rules based on GOF indexes and, on this basis, proposed new and more stringent cutoff values for many indexes. This article discusses potential problems underlying the hypothesis-testing rationale of their research, which is more appropriate to testing statistical significance than evaluating GOF. Many of their misspecified models resulted in a fit that should have been deemed acceptable according to even their new, more demanding criteria. Hence, rejection of these acceptable-misspecified models should have constituted a Type 1 error (incorrect rejection of an "acceptable" model), leading to the seemingly paradoxical results whereby the probability of correctly rejecting misspecified models decreased substantially with increasing N. In contrast to the application of cutoff values to evaluate each ...

5,013 citations

Journal ArticleDOI
TL;DR: The WHOQOL-Bas discussed by the authors as discussed by the authors is an abbreviated version of the WHOQol-100 quality of life assessment, which produces scores for four domains: physical health, psychological, social relationships and environment.
Abstract: Background. The paper reports on the development of the WHOQOL-BREF, an abbreviated version of the WHOQOL-100 quality of life assessment. Method. The WHOQOL-BREF was derived from data collected using the WHOQOL-100. It produces scores for four domains related to quality of life: physical health, psychological, social relationships and environment. It also includes one facet on overall quality of life and general health. Results. Domain scores produced by the WHOQOL-BREF correlate highly (0.89 or above) with WHOQOL-100 domain scores (calculated on a four domain structure). WHOQOL-BREF domain scores demonstrated good discriminant validity, content validity, internal consistency and test-retest reliability. Conclusion. These data suggest that the WHOQOL-BREF provides a valid and reliable alternative to the assessment of domain profiles using the WHOQOL-100. It is envisaged that the WHOQOL-BREF will be most useful in studies that require a brief assessment of quality of life, for example, in large epidemiological studies and clinical trials where quality of life is of interest. In addition, the WHOQOL-BREF may be of use to health professionals in the assessment and evaluation of treatment efficacy. [References: 9]

4,897 citations