Child and Adult Factors Related to Quality of Life in Adults with Autism
Child and Adult Factors Related to Quality of Life in Adults with Autism
Philippa Moss 0 1 2
William Mandy 0 1 2
Patricia Howlin 0 1 2
Autism 0 1 2
Quality of Life 0 1 2
Adult 0 1 2
Adult 0 1 2
0 Institute of Psychiatry, Psychology and Neuroscience, King's College , Denmark Hill, London SE58AF , UK
1 Research Department of Clinical , Educational and Health Psychology , University College London , Gower Street, London WC1E 6BT , UK
2 Great Ormond Street Hospital , Level 3, Italian Building, Great Ormond Street, London WC1N 3JH , UK
The WHO Quality of Life-Brief questionnaire was used to assess quality of life (QoL) among 52 adults with autism (mean age 49 years) followed-up since childhood. Overall, assessments of QOL were more positive than measures of objective social outcome (jobs, independence, relationships etc.) but correlations between caregiver and self-reports were low. Informant ratings indicated few correlations between current QoL and any child or adult factors. On self-report ratings, QoL was significantly negatively correlated with severity of repetitive behaviours in childhood; higher QoL was positively associated with better adult social outcomes. However, only a minority of adults (n = 22) could provide self-report data and findings highlight the need to develop valid measures for assessing the well-being of adults with autism.
Most studies of adults with autism spectrum disorders
(ASD) suggest that prognosis, as assessed by objective
measures of social outcome (e.g. independence,
employment, social relationships), is poor (Howlin and Magiati
2017). However, recently there been a focus on broader and
more subjective measures, such as those assessing general
quality of life (QoL). Although quality of life in autism
tends to be lower than in the general population (Barneveld
et al. 2014; Chiang and Wineman 2014; Egilson et al. 2016;
Ikeda et al. 2014; Jonsson et al. 2016; Kamp-Becker et al.
2011; Van Heijst and Geurts 2015), assessments of QoL
amongst adults with ASD often prove more positive than
normative measures of social functioning (Billstedt et al.
2011; Bishop-Fitzpatrick et al. 2016; Helles et al. 2016;
Henninger and Taylor 2013; Hong et al. 2016; Renty and
Roeyers 2006). Nevertheless, findings vary according to the
particular QoL measures and methodologies used (Jonsson
et al. 2016). Several studies, mainly involving children and
adolescents, have also reported significant discrepancies
between self and informant ratings (Clark et al. 2015; Ikeda
et al. 2014; Jonsson et al. 2016). Although self-reports of
QoL tend to be more positive than informant reports (e.g.
Clark et al. 2015; Egilson et al. 2016; Hong et al. 2016;
Ikeda et al. 2014) this is not always the case (Jonsson et al.
2016). Moreover, findings on the associations between QoL
and factors such as autism severity, age, gender, cognitive,
social and language skills, adaptive behaviours,
behavioural disturbance, physical health, and co-morbid
psychiatric conditions are variable, and sometimes contradictory
(Biggs and Carter 2016; Chiang and Wineman 2014; Hong
et al. 2016; Ikeda et al. 2014; Kamio et al. 2013; Van Heijst
and Geurts 2015). Suggestions that support networks may
have a stronger impact on QoL in autism than individual
characteristics (Renty and Roeyers 2006) have also led
to exploration of a wide range of potential
environmental influences. These include bullying, maternal warmth
and relationships, participation in social and recreational
activities, level of school inclusion, quality of
neighbourhood, independence in daily activities, and levels of stress
(Bishop-Fitzpatrick et al. 2016; Hong et al. 2016;
Woodman et al. 2016). However, the relative influence of these
variables, the interactions between them, or how
associations may change with age, remains uncertain.
Background to the Present Study
Over the past four decades years we have followed up a
cohort of 60 individuals initially diagnosed with autism as
children (see Howlin et al. 2004 for details). Child
diagnoses (at mean age 6 years) were confirmed with the Autism
Diagnostic Interview (Le Couteur et al. 1989) and
re-confirmed in adulthood (mean age 44 years) using the Autism
Diagnostic Interview-Revised (ADI-R; Rutter et al. 2003).
As children, all participants had a non-verbal IQ of ≥70;
data were also collected on language and autism severity
(Howlin et al. 2004). Adult data included assessments of
cognitive and social functioning, and mental health. Almost
all individuals (92%) showed a decrease in autism severity
over time and IQ, for most, remained stable or increased
(Howlin et al. 2013, 2014; Moss et al. 2015).
Nevertheless, most adults (60%) were rated as having a poor social
outcome and 28% had severe mental health problems.
Outcome was particularly poor in those individuals (25% of
sample) who, for behavioural or other reasons, could no
longer complete standard IQ assessments and therefore
showed deterioration in measured IQ (Details in
Supplementary Material, note 1; Howlin et al. 2014).
Information collected on this cohort over many years allowed us to
examine the association between individual characteristics
(both child and adult) and current quality of life.
Our principal research aims were:
1. To assess quality of life in a UK cohort of adults with autism, using the WHO Quality of Life-Brief Version (WHOQOL-BREF, 1998; see below).
2. To investigate the association between self and informant perceived QoL scores in those individuals who were able independently to complete the WHOQOLBREF.
3. To examine childhood and adult characteristics associated with current QoL. Variables studied included age, autism severity, IQ and language, and, in adulthood, ratings of social outcome and mental health. We also
explored whether there was any association between
current QoL and changes in IQ or autism
symptomatology scores over time. Given the inconsistencies
in previous research findings, no specific hypotheses
about the relationship between QoL and the variables
studied were proposed.
Recruitment Procedure and Ethics
Of 60 families involved in the adult follow-up cohort
(Howlin et al. 2013, 2014), 59 had consented to be contacted for
future research. Approximately 3–4 years after their
previous assessments, letters requesting participation in a study
of quality of life were sent to these families and included
an information sheet, consent forms, the WHOQOL-BREF
informant version, and, if appropriate, the self-report
version (see below). In total, quality of life data were available
for 52 individuals (43 male, 9 female; positive response
rate: 88% from previous adult follow-up). Non-responders
(n = 7) were similar to responders in terms of age, IQ and
mental health but they had lower autism severity scores
(d = 1.08) and better social outcome ratings (d = 0.63) than
responders (Supplementary Table 1).
Ethical approval was granted by the Maudsley hospital/
Institute of Psychiatry and UCL ethics committees (project
references IOP 07/H0807/65; UCL 4111/001). Informed
consent was obtained from all participants.
Data on IQ, language and autism severity were collected
in childhood (M = 6.3 years; SD = 2.1, range 2–13 years)
and in adulthood (M = 47.9 years; SD = 9.5; range 33–68
years). In adulthood, information was also gathered on
social functioning and mental health (see Tables 1, 2; full
details:Howlin et al. 2004, 2013, 2014; Moss et al. 2015).
The informant WHOQOL-BREF was completed by 50
caregivers (37 parents, 7 siblings; 6 care staff). There was
no effect of informant on QoL ratings (See
Supplementary Note 2). The self-report version was completed by 22
adults. This relatively low number is due to the fact that
several participants were unable to complete standardised
assessment measures at follow-up (See Supplementary
Note 1; Howlin et al. 2014). Thus, only individuals able
to complete a standardised IQ test were asked to complete
the self -report measure. As well as these individuals being
more cognitively able than the rest of the cohort they had
significantly fewer autism symptoms and higher social
outcome ratings (Supplementary Table 2).
Table 1 Child and adult characteristics
aBest estimate 1Q based on highest level IQ test that participant was able to complete (See Supplementary Note 2)
bLanguage score missing for one person. *p ≤ 0.05; ***p ≤ .001
Table 2 Adult participant ratings: Composite ratings for social
outcomes and mental health
See Supplementary Tables 3 (a & b) and 4 for details of codings
aMental health outcome scores missing for three participants
Quality of Life The WHOQOL-BREF (WHOQOL Group,
1998) is a 26-item questionnaire based on the original
100item WHOQOL. Ratings (0-Very poor to 4-Very good) are
based on the past month and generate four domain scores:
(i) Physical health, (ii) Psychological well-being, (iii)
Social relationships, (iv) Quality of environment. Scores
are transformed into a 0–100 scale. Mean scores for a UK
“Well” sample (n = 1324) range from 67 to 76 for individual
domains (Skevington and McCrate 2012). The measure also
includes two general questions; (Q1) ‘How would you rate
[his/her][your] quality of life?’ and (Q2) ‘How satisfied [are
you] [is he/she] with [your] [his/her] health?’.
The WHOQOL-BREF has good-to-excellent
psychometric properties (Hawthorne et al. 2006; Skevington and
McCrate 2012) and has been used with a range of
samples including a higher ability adult autism group (Kamio
et al. 2013). As most (62%) of the adults in the present
study had been living away from home for some years
and 25% had no or very limited phrase speech,
informants’ own perceptions of the adult’s quality of life were
assessed rather than proxy ratings (i.e. carers reporting
what they think the individual with ASD believes their
own QoL to be).
Autism Symptomatology, Cognitive and Language
Level Autism severity was assessed using the “Current”
form of the ADI-R (Rutter et al. 2003) completed by
parents/caregivers. IQ scores were based, where possible, on
the Wechsler Adult Intelligence Scale-III (Wechsler et al.
1997). If an individual could not complete this, an
alternative test was used (Supplementary Note 3). Language
was rated using the ADI/ADI-R summary categories (<5
words; no functional phrase speech; functional use of
Social and Mental Health Outcomes These were
assessed using the informant version of the Family
History Schedule (FHS), a semi-structured interview used
in many autism studies (e.g. Bolton et al. 1994; Pickles
et al. 2000; Pinto et al. 2010). A composite social outcome
score was derived from ratings for employment,
relationships and independent living. A composite mental health
score was based on FHS scores for five areas of mental
health difficulties (OCD, episodic depression, chronic
depression, bipolar disorder, anxiety disorder). (See
Supplementary Tables 3 (a & b) and 4; Howlin et al. 2013;
Moss et al. 2015).
Child Performance IQ scores were obtained from the test
most appropriate for the child’s mental age. Autism
severity scores and ratings of language level at diagnostic
confirmation were based on the ADI (Le Couteur et al. 1989).
(Full details in Howlin et al. 2004, 2013, 2014).
Power analysis was based on earlier follow-up research
(Farley et al. 2009; Howlin et al. 2013) reporting
significant associations between adult outcome and various child
and adult variables (range −0.34 to 0.83). Using these data,
and assuming a correlation ≥0.4 is of likely clinical
significance (Pallant 2007), a sample size of 47 was required for a
aNot all individuals completed each domain. *p ≤ .05; **p ≤ .01
Pearson correlation to have 80% power to detect a
statistically significant association (two-tailed alpha= 0.05).
Parametric tests were used unless assumptions of
normality were violated. Due to the number of group
comparisons conducted, significance level was set at p < .01 (all
tests 2 tailed); effect sizes (Cohen’s d/Hedges delta) are also
reported. Given the exploratory nature of the correlational
analyses, all findings with a p value <0.05 are discussed.
Regression analysis was conducted only if there were
multiple significant correlations with a particular QoL domain.
Table 3 summarises WHOQOL-BREF informant and
selfreport scores for the total sample. On informant ratings, the
proportions scoring within at least one standard deviation
of population norms (Skevington and McCrate 2012) were
as follows: Physical 89%; Psychological 78%; Social 80%;
Environment 98%. For self-ratings the proportions within
one standard deviation of population norms were:
Physical 100%; Psychological 91%; Social 91%%; Environment
For the sample as whole, informant ratings for the
physical, psychological and social domains tended to be lower
than self-ratings. Despite the higher cognitive and social
functioning of individuals who were able to self-report
(Details Supplementary Table 2) there were no differences
in informant ratings for participants with or without
selfreport data (Table 4); however, effect sizes for the
Psychological domain were in the moderate range.
Comparisons of self and informant scores for those
individuals (n = 20) with both sources of data (Table 5)
indicated that self-report scores were generally higher but the
difference only reached significance, with moderate effect
Table 5 WHOQOL-BREF: Informant and participant scores for
those individuals (n = 20) with both sources of data
QoL and Changes in Cognitive Ability and Autism
Symptoms over Time
aPsychological ratings missing for one pair. *p ≤ 0.05.; bWilcoxon z
used as data significantly skewed
sizes, for the social domain and Question 1 (overall Quality
of Life). Although most self-informant correlations were
small to moderate, agreement on the social and
environmental domains was extremely low.
Variables Associated with Adult QoL (See
Supplementary Tables 5 & 6 for all correlations)
On the informant WHOQOL-BREF there were no
significant correlations with any childhood factors. On the
selfreport measure, there was a significant negative
correlation between ADI total score and overall satisfaction with
health (Q2) (r = −0.55, p < .01; i.e. greater autism symptom
severity is associated with less satisfaction with health).
Poorer overall self-reported QoL (Q1) was associated with
higher childhood IQ (r = −0.44); higher levels of childhood
repetitive and stereotyped behaviours were associated with
poorer physical (r = −0.44), psychological (r = −0.50) and
environmental (r = −0.51) QoL (all p values <0.05).
On the Informant measure, only one association emerged,
between older participant age and poorer physical QoL
(r = −0.34; p < .05). On the self-report WHOQOL, social
satisfaction scores were significantly positively associated
with adult social outcome ratings (r = 0.57; p < .01) but
negatively associated with IQ (r = −0.56; p < .05). When
these two variables were entered in a regression model,
the overall model was highly significant [F(2,16)= 8.4,
p = .003), explaining a large proportion of variance in
social QoL (r2 = 0.51). Within this model social outcome
was a significant predictor (standardised beta= 0.54,
p = .024); adult IQ was no longer significant (standardised
beta = −0.24, p = .286).
There was no significant association between change in
ADI scores over time and current QoL total score, (self
[r = 0.11] or informant [r = 0.16]). The correlation with
change in IQ was non-significant for self-report QoL
(r = 0.03) but just reached significance for informant QoL
(r = 0.35; p < .05). Further analysis indicated no significant
group differences (at p< .01) in any informant-based QoL
ratings between individuals showing a significant decline
(>2 standard deviations) in cognitive scores and
individuals whose IQ had remained stable from child to adulthood.
(Details Supplementary Table 7).
The present study investigated informant perceived and
self-report ratings of quality of life among a cohort of
adults with autism first seen in early childhood. Replicating
the findings of Hong et al. (2016), most adults and
informants reported relatively good QoL. WHOQOL-BREF
ratings (self and informant) were also comparable to those
reported by Hong et al. (2016) and were mostly within one
standard deviation of the means reported for individuals
without disabilities in the general population (Hawthorne
et al. 2006; Skevington and McCrate 2012; see
Supplementary Table 8). Overall, findings are in agreement with
previous studies suggesting that measures focusing on
general well-being provide a more positive picture than those
focussing on outcomes such as jobs and independent living
(e.g. Billstedt et al. 2011; Bishop-Fitzpatrick et al. 2016;
Helles et al. 2016; Henninger and Taylor 2013; Hong et al.
2016; Renty and Roeyers 2006).
Nevertheless, correlations between self and informant
reports were generally low. In particular, self-ratings for
social relationships were significantly more positive than
informant scores, suggesting that adults in this sample were
more satisfied with their social lives than perceived by
others. Hong et al. (2016) also found that self and maternal
ratings were generally similar, apart for social relationships,
which, as in the present study, were viewed more positively
by the individuals with ASD.
Existing data on the individual characteristics correlated
with QoL are often inconsistent, with different studies
identifying very different associations. Unlike some other
studies (e.g., Bishop-Fitzpatrick et al. 2016; Helles et al. 2016;
Kamp-Becker et al. 2011), we identified few child or adult
variables that were strongly associated with current self or
informant rated QoL. Similarly, there was little
association between WHOQOL-BREF scores and changes in IQ
or autism symptomatology over time. Other variables that
might be expected to show some degree of association (e.g.
ratings of adult social functioning and WHOQOL-BREF
social domain informant scores; adult mental health ratings
and WHOQOL-BREF psychological well-being) showed
Self-reports indicated rather more, albeit moderate,
associations between childhood variables and adult QoL
than informant reports. In particular, higher self-ratings on
the social satisfaction domain were related to more
positive social outcome scores. There were significant negative
associations, too, between WHOQOL-BREF self-report
and severity of childhood autism features, especially related
to stereotyped and repetitive behaviours. This parallels the
reported association between higher levels of early
autistic symptomatology and lower, objective ratings of adult
outcome (Howlin and Magiati 2017). Although previous
research has suggested that higher adult IQ is associated
with better social outcomes (Howlin and Magiati 2017), in
this cohort individuals with higher cognitive levels tended
to report lower social satisfaction. However, the effects of
IQ were limited when overall social functioning was taken
Strengths and Limitations
The present study has a number of strengths. These
include the relatively large sample size, the high
retention rate over the years, and access to a range of child
and adult measures permitting analyses of factors related
to current quality of life. Nevertheless, various
methodological issues limit the generalizability of findings. In
particular, this was a highly selected cohort, diagnosed
at a time when autism was far less well recognised and
hence participants may have had more severe autistic
symptomatology than is typical of children of average IQ
who are currently diagnosed. Moreover, only a minority
of adults completed the self-report measure and
statistical power for those analyses was low. Individuals able to
self-report were also more able than those for whom only
informant data were available, although informant
ratings for these two subgroups were similar. In addition, we
have no information about QoL among those individuals
(n = 7) who did not participate in this phase of the
followup study. It is also unknown whether face-to-face
administration of the WHOQOL-BREF, possibly using a
modified format (cf. Hong et al. 2016), might have affected the
results and/or allowed more adults to take part. It is
possible, too, that agreement between self and informant data
may have been greater if proxy reports had been used
instead of relying on caregivers’ perceptions of
individuals’ QoL (Hong et al. 2016; Sheldrick et al. 2012).
Correlations between the WHOQOL-BREF and other child
variables may also have been attenuated by the relative
homogeneity of IQ in childhood; however, that would
not explain the lack of correlations with IQ in adulthood,
where the range was wider. A further caveat is the lack of
information on environmental variables (family factors,
specific interventions, educational and social provision
etc.) that have been identified as important in other
studies (e.g. Bishop-Fitzpatrick et al. 2016; Renty and
Roeyers 2006). Finally, there was a 3–5 year gap between the
assessments of IQ and social functioning/mental health
and the collection of WHOQOL-BREF data, although
there was no evidence of any significant changes in
psychological, physical or social circumstances during this
Measuring Quality of Life
Despite increasing focus on quality of life for adults with
autism, there is little agreement on the most appropriate
measures to use, or which of the multitude of variables
that might affect QoL should be studied. Correlations
between self and informant reports are typically low and
data on variables associated with QoL are often
inconsistent. The inability (or unwillingness, cf Helles et al.
2016) of some individuals to complete standard QoL
assessments also raises questions about the utility of such
measures for the wider autism population, especially
for individuals of lower ability. The validity of proxy
reports (what the caregiver thinks the individual with
ASD believes his/her own QoL to be) remains
uncertain for adults with very low cognitive and
communication skills. On the other hand, informant perceived QoL
(caregivers’ own perceptions of the adult’s quality of life)
might be affected by their own aspirations and/or
anxieties for his/her future. And, even for more able
individuals with autism, we cannot be certain that they interpret
self-report questions in the same way as in the general
In the present study, WHOQOL-BREF scores were
comparable to those reported for another adult cohort of
slightly younger but more intellectually impaired adults
(Hong et al. 2016). Informant scores for higher and lower
ability participants were also very similar, suggesting the
potential utility of this instrument across a relatively wide
range of ability. Nevertheless, only a minority of
participants was able to self-report, and the impact of some
suggested adaptations (to wording, content, mode of
presentation, or scoring; cf. Hare et al. 2015; Hong et al. 2016;
Power and Green 2010) to increase participation, remains
unknown. Instead, Tavernor et al. (2013) recommend the
development of a syndrome specific measure of QoL,
constructed with the active involvement of individuals with
autism and their families.
Although previous research on autism in adulthood
indicates that prognosis for most individuals is poor, studies
focussing on more general measures of wellbeing indicate
a more encouraging outlook. However, conclusions differ
according to the information source and measures used,
and many questions remain about the factors, both
individual and environmental, that influence quality of life. Given
growing demands for autism research to reflect the
values of individuals with autism themselves (Pellicano et al.
2014), it is becoming increasingly important to develop
appropriate, valid and comprehensive measures of
wellbeing that can be used across the whole autism spectrum.
Acknowledgments We are most grateful to all the families and
individuals with autism who gave so generously of their time during
the course of the study. The earlier stages of the long-term follow-up
were funded by the Nuffield Foundation and the Bethlem-Maudsley
Research Trust. The present paper was based on the work completed
as part of Dr Moss’s Doctorate in Clinical Psychology.
Author Contributions PM designed the study, was responsible for
data collection, and prepared the original draft paper; WM and PH
participated in the study design and interpretation of the data; PH
was responsible for the final draft of the paper. All authors read and
approved the final manuscript.
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