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Weighted Blankets and Sleep in Autistic
Children—A Randomized Controlled Trial
WHAT’S KNOWN ON THIS SUBJECT: Children with autism sleep
poorly compared with their peers. Sensory integration, including
use of weighted blankets, is proposed as a means to reduce
arousal and stress. There is, however, no evidence that weighted
blankets can improve sleep for these children.
WHAT THIS STUDY ADDS: This is the first robust study to evaluate
the impact of weighted blankets and show that they do not
improve sleep parameters in children with autism spectrum
disorder.
abstract
OBJECTIVE: To assess the effectiveness of a weighted-blanket interven-
tion in treating severe sleep problems in children with autism spectrum
disorder (ASD).
METHODS: This phase III trial was a randomized, placebo-controlled
crossover design. Participants were aged between 5 years and 16 years
10 months, with a confirmed ASD diagnosis and severe sleep problems,
refractory to community-based interventions. The interventions were ei-
ther a commercially available weighted blanket or otherwise identical
usual weight blanket (control), introduced at bedtime; each was used
for a 2-week period before crossover to the other blanket. Primary out-
come was total sleep time (TST) recorded by actigraphy over each 2-week
period. Secondary outcomes included actigraphically recorded sleep-
onset latency, sleep efficiency, assessments of child behavior, family
functioning, and adverse events. Sleep was also measured by using
parent-report diaries.
RESULTS: Seventy-three children were randomized and analysis
conducted on 67 children who completed the study. Using objective
measures, the weighted blanket, compared with the control blanket,
did not increase TST as measured by actigraphy and adjusted for
baseline TST. There were no group differences in any other objective
or subjective measure of sleep, including behavioral outcomes. On
subjective preference measures, parents and children favored the
weighted blanket.
CONCLUSIONS: The use of a weighted blanket did not help children
with ASD sleep for a longer period of time, fall asleep significantly
faster, or wake less often. However, the weighted blanket was favored
by children and parents, and blankets were well tolerated over this
period. Pediatrics 2014;134:298–306
AUTHORS: Paul Gringras, MBChB, MRCP, MsC,
a
Dido Green,
DipCOT, MSc, PhD,
b
Barry Wright, MBBS, MD, FRCPsych,
c
Carla Rush, BSc,
a
Masako Sparrowhawk,
d
Karen Pratt,
a
Victoria Allgar, PhD, CStat, CSci,
d
Naomi Hooke,
c
Danielle
Moore,
c
Zenobia Zaiwalla,
e
and Luci Wiggs, DPhil,
CPsychol
d
a
Children’s Sleep Medicine, Evelina London Children’s Hospital,
St Thomas’Hospital, London, United Kingdom;
b
Centre for
Rehabilitation and
d
Department of Psychology, Oxford Brookes
University, Oxford, United Kingdom;
c
Lime Trees Child and Family
Unit, York, England; and
e
Department of Clinical Neurophysiology,
John Radcliffe Hospital, Oxford, United Kingdom
KEY WORDS
autism spectrum disorder, severe sleep problems, weighted
blankets, total sleep time, children
ABBREVIATIONS
ABC—Aberrant Behavior Checklist
ASD—autism spectrum disorder
CONSORT—Consolidated Standards of Reporting Trials
CROS—crossover analysis
CSDI—Composite Sleep Disturbance Index
SCQ—Social Communication Questionnaire
SOL—sleep onset latency
SSPCQ—Short Sensory Profile Caregiver Questionnaire
TST—total sleep time
Professor Gringras was involved in the design of the study, the
funding application, development of the protocol, and
recruitment of patients as a local principal investigator; was
co–chief investigator for the trial and a member of the trial
management group; and cowrote the article; Dr Wiggs
contributed to the design of the study, the funding application,
and development of the protocol; advised on the use of
actigraphy and patient-reported outcomes; was principal
investigator and co–chief investigator for the trial; was
a member of the trial management group; and helped write the
article; Ms Rush coordinated the trial, recruited patients, scored
actigraphy, helped write the article, and was a member of the
trial management group; Ms Sparrowhawk and Ms Pratt
recruited patients, helped write the article, and were members
of the trial management group; Dr Wright helped recruit
patients and coordinate the trial, helped write the article, was
co–principal investigator for the trial, and was a member of the
trial management group; Ms Hooke and Ms Moore helped
recruit patients, respond to family queries, and collect and
record data; Dr Allgar helped with the statistical analysis plan,
analyzing data, and writing the article; Dr Green contributed to
the design of the study, the funding application and ethical
submission, advised on the use of sensory questionnaires and
patient reported outcomes, helped write the article, and was
a member of the trial management group; and Dr Zaiwalla
helped with the initial study design and recruitment as lead
clinician from the Oxford Group and helped write the article.
(Continued on last page)
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Children with autism spectrum disorder
(ASD) are more likely to have disturbed
sleep than typically developing children,
with a prevalence of sleep disturbance in
children with ASD between 40% and
80%.
1
The most commonly reported
sleep disturbances are increased sleep
latency (time to fall asleep) and frequent
night waking, which result in reduced
sleep duration.
2
The etiology of sleep
disorders in ASD is poorly understood.
3
Sleeping difficulties are frequently
chronic, resulting in additional learning
and behavior problems
4
and affecting
the whole family’s well-being. Behavioral
interventions work with some children,
but not all.
5
Pharmacological inter-
ventions, with exogenous melatonin, have
shown potential for reducing sleep latency
by ∼30 minutes but have a less significant
impact on total sleep time (TST).
6,7
Weighted blankets are often recommen-
ded by professionals who work with young
people with ASD to assist with calming and
relaxation, as well as to assist with
sleeping.
8,9
The theory underlying the
reasons for using weighted blankets and
other weighted items for calming pur-
poses is based on sensory integration.
10
It
is hypothesized that the deep pressure
and more consistent sensory input pro-
vided by weighted items reduces the
body’s physiologic level of arousal and
stress, which might improve sleep. Al-
though weighted blankets potentially of-
fer a relatively cheap, nonpharmacologic
intervention, research on their efficacy in
children with ASD is lacking. This trial
was therefore conceived to establish
whether this novel intervention could in-
crease TST and improve other sleep
parameters in children with ASD.
METHODS
Study Design and Oversight
This randomized, multicenter, controlled,
crossover phase III trial was undertaken
in 3 sites in England. The study was ap-
proved through the UK Integrated Re-
search Application System and the
review board of each participating center
and was conducted in accordance with
the International Conference on Harmo-
nization Good Clinical Practice Guidelines
and the Declaration of Helsinki. Written
informed consent was obtained from the
legal guardians of the children. Informed
written assent was also obtained from
competent study participants between 8
and 16 years of age.
Study Population
Children were eligible to participate if
they were aged between 5 years and 16
years 10 months and had an ASD di-
agnosis and if their parents reported
a sleep problem (as defined later), for at
least the previous 5 months. The di-
agnosis of ASD was reached if clinical
records from the local multidisciplinary
team agreed to an unequivocal ASD
diagnosis including autism, Asperger
syndrome, or pervasive developmental
disorder not otherwise specified. In
addition to consideration of school
reports and direct observations, these
teams used a range of standardized
diagnostic instruments reflecting usual
ASD diagnostic practice in the United
Kingdom.
11,12
Sleep problems were
characterized as failing to fall asleep
within 1 hour of “lights off”on 3 of
5 nights and/or achieving ,7hoursof
continuous sleep on 3 of 5 nights. Chil-
dren were not included if they were
known to suffer from obstructive sleep
apnea, night terrors, or other disorders
likely to have an impact on sleep. Two
amendments were made to the eligibility
criteria after trial commencement: the
age for inclusion was raised by 1 year to
16 years 10 months, and patients on
astabledoseofpermittedmedicationfor
.6monthswereincluded(seeprotocol).
These changes were to maximize re-
cruitment without affecting trial fidelity.
Intervention
A number of commercially available
weighted blankets in common use that
adhered to the original guidance on sen-
sory interventions as proposed by Ayres
10
(providing constant proprioceptive stim-
ulation distributed across the body) were
considered by the senior occupational
therapist of this study (DG). A specific
weighted blanket used in the United
States and United Kingdom was chosen.
The weighted blanket weighed 2.25 kg
(small) or 4.5 kg (large) and was heavy
without being thick (and therefore too
warm) through the use of 3-mm steel shot
pellets embedded evenly throughout the
blanket. Although we were aware that
blinding child and parent to the different
weights of study and control blanket was
impossible, we matched the control
blankets by size, color, and texture of the
material. Some children with ASD during
pilot stages were aware of the subtle
texture of the weighted blankets’steel
shot, and so we commissioned the sup-
pliers to incorporate lightweight plastic
beads identical in size to the steel shot
into the bespoke control blankets.
Two sizes of blankets (small: 147 376 cm;
large: 152 3152 cm) according to the
size of child were used, consistent with
recommendations by manufactures and
therapists.
Procedures
After screening and consent, eligible
participants began a baseline adapta-
tion and monitoring period of 7 to 21
days.
During treatment phases, each blanket
was used for 12 to 16 days, with actigraphy
and sleep diary monitoring. After the first
treatment phase, the researchers re-
moved the initial blanket, diaries, and
actigraph and provided the next blanket,
actigraph, and new sleep diaries. Care
was taken to ensure that the baseline and
intervention phases were conducted
during school-term time and that no
breaks occurred between interventions
(avoiding school holiday periods, for ex-
ample). All interviews and data collection
were carried out by the researchers and
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visits took place in clinic, within desig-
nated schools, or whenever possible, the
patients’homes.
Randomization
Remote randomization was carried out by
Kings Clinical Trial Unit by using block
randomization with random variable block
lengths of 2 and 4, and stratified by center.
Randomization requests were generated
by the researchers, who then dispensed
the allocated treatments. Because of the
nature of t he treatment, research ers were
unblinded; however, all trial investigators
(PG, DG, LW, BW) and the statistician (VA)
were blind to treatment allocation
throughout the trial and analysis.
Measuring Sleep
The trial design included both objective
(actigraphy) and subjective (parent-
completed diary) measures of sleep as
recommended by Sadeh.
13
There are
benefits with each approach and also
reasons the results may not be concor-
dant
14,15
; for example, sleep diaries would
not detect periods when the child was
awake but not disturb the household (a
particular concern for determining sleep
onset latency [SOL]), and actigraphy may
interpret restless sleep as being awake.
The actigraph (Micro Mini Motionlog-
ger, Ambulatory Monitoring, Ardsley,
NY), an accelerometer, was worn on the
nondominant wrist, and movement was
monitored continuously and stored
within the unit. Subsequent analysis of
frequency and pattern of movement by
means of validated algorithms permits
detection of basic sleep–wake pat-
terns.
13
Movements were scored in
1-minute epochs; all epochs that are
scored above a preset threshold using
an algorithm by Sadeh
13
are scored as
“awake”and those that are below this
threshold are scored as “sleep.”
Study Outcomes
Various assessments of sleep parame-
ters, sensory profiles, daytime behaviors,
and perceptions of blanket use were
conducted at different time points (Table1).
The primary outcome was TST, measured
by actigraphy. A minimum of 5 of 7 nights’
actigraphy data (or $71% if .7nights
were captured) was required at baseline
and during each blanket phase, and
averages were calculated at each time
point. Children not meeting this re-
quirement were excluded from the data
analyses of the main research questions.
Secondary sleep outcomes included TST
measured by parental diary; SOL mea-
sured by diaries and actigraphy; and sleep
efficiency (the proportion of time spent in
bed asleep) measured by actigraphy.
Three questionnaires were completed at
baseline and at the end of both in-
tervention periods: the Composite Sleep
Disturbance Index (CSDI; frequency and
duration of sleep problems),
16–18
the
Aberrant Behavior Checklist (ABC; to as-
sess behavioral problems),
19,20
and the
Sensory Behavior Questionnaire (SBQ;
sensory stimuli response profile).
21
Three questionnaires were only com-
pleted at baseline: the Children’sSleep
Habits Questionnaire (a parent-report
validated sleep screening instrument),
the Social Communication Questionnaire
(SCQ; a screening instrument for ASD),
22
and the Short Sensory Profile Caregiver
Questionnaire (SSPCQ; a questionnaire
to establish a profile of children’ssen-
sory responses).
23
The trial flowchart
canbeseeninFig1.
Children and parents also completed
subjective ratings of sleep quality and
acceptability of the blanket. The sleep diary
contained a section for parents to estimate
thepercentageofthenighttheblanketwas
in contact with the child’sbody.
The frequency and severity of adverse
events were monitored carefully through
a 24-hour telephone number and weekly
parent reviews (face-to-face or telephone).
Statistical Considerations
The “intention to treat”principle was
used throughout, with analyses un-
dertaken by using SPSS (version 20; SAS
Institute, Cary, NC).
24
Missing data for
questionnaire responses were prorated
if ,10% was missing, and data were
excluded otherwise.
The TST primary outcome (actigraphy)
was analyzed by taking the average TST
over baseline and each of the 2-week
intervention periods. It was powered at
80% with a 5% significance level to
detect a change from baseline of 40
minutes between the study blanket and
placebo blanket periods using a com-
mon SD of 1.7.
24,25
Allowing for 20%
missing data based on pilot work, 63 in
total were required.
The actigraphy data and sleep diary
outcomes were analyzed by taking the
average TST (actigraphy and diary) and
average SOL (actigraphyand diary) over
the baseline and each of the 2-week
intervention periods. At baseline a
TABLE 1 Baseline Characteristics of the Study Population
Baseline Characteristic Weighted Blanket First (n= 32) Control Blanket First (n= 35)
Male, n(%) 28 (88%) 26 (74%)
Age (y), mean (SD) 8.7 (3.3) 9.9 (2.8)
SCQ score, mean (SD) 19.7 (5.9), 11–33 20.3 (6.0), 6–32
ASD diagnosis, n(%)
Autism 8 (25) 13 (37)
Asperger syndrome 16 (50) 17 (49)
ASD 8 (25) 5 (14)
Sensory profile (Dunn
23
) 108.62 (21.6) 117.60 (22.7)
Mean (SD), range 73–154 65–186
Sleep disorder, n(%)
Delayed sleep onset 29 (91) 31 (86)
Poor sleep maintenance 17 (53) 19 (54)
Poor sleep onset and maintenance 14 (44) 15 (43)
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descriptive summary was undertaken
between the randomization groups, with
mean (SD) or median (interquartile
range) for continuous data and n(%) for
categorical data. No statistical tests
were used to compare baseline data
(Consolidated Standards of Reporting
Trials [CONSORT]; http://www.consort-
statement.org/downloads).
The primary analysis was to compare
TSTwhen using weighted blanket versus
control blanket (actigraphy). To rule out
a period effect, a crossover analysis
(CROS) was undertaken. The sum of the
TST values was calculated for the time
period when using weighted blanket
and when using control blanket for each
subject. This was compared across the
sequence groups by means of an in-
dependent ttest. Where the test was
not significant, this indicated that there
was no evidence of a period effect.
26
The second stage of CROS is to test the
difference between the weighted blanket
and the control blanket. The differences in
the TST were calculated between the first
period and the second period, and this
difference was compared across the se-
quence groups by means of an in-
dependent ttest. This method of analysis
adjusts for the period effect and so
reduces the effect of any period difference.
This was then followed by the more con-
ventional analysis of a CROS by using
apairedttest to compare TSTwhen using
weighted blanket versus TST when using
control blanket, which was irrespective of
starting group. The existence of cross-
over effects must be ruled out before this
method is valid (see http://www.ncbi.nlm.
nih.gov/pmc/articles/PMC3345345).
The same statistical procedures were
followed for secondary sleep data. For
data from the SPBQ, ABC, and CSDI,
a CROS was again undertaken, by using
Mann-Whitney tests to examine the
crossover effect. A Wilcoxon paired test
was then used to compare the study
blanket and control blanket scores,
irrespective of starting group where the
existence of crossover effects was ruled
out. Exploratory analysis of sensory
influenceson TSTin responseto blankets
was undertaken by using repeated-
measures analysis of variance.
23
All analyses were performed on SPSS
(version 20; IBM SPSS Statistics, IBM
Corporation). P,.05 was considered
to indicate statistical significance.
RESULTS
Seventy-three children were recruited
and followed up between August 2011
and October 2012.
The CONSORT diagram in Fig 2 shows the
screening, randomization, and follow-up
FIGURE 1
Trial flowchart. T, time.
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of the patients. Baseline characteristics
were similar between groups (see Table 1).
Seventy-three patients were random-
ized, and 6 were subsequently excluded.
Fourcould not tolerate or declined to use
the weighted blanket, 1 chose to with-
drawto attend an alternativeclinic,and 1
had an unrelated illness and could not
continue. The baselinecharacteristics of
the 2 groups can be seen in Table 1.
It is interesting to note that despite
agreed ASD diagnoses from multidisci-
plinary teams, 13 (19%) were not above
the recommended cutoff of 15 on the
SCQ, butof these 11 wereabove the cutoff
of 11 discussed in the review by Norris
and Lecavalier
27
as the cutoff with
maximum sensitivity and specificity.
Sleep Outcomes
Actigraphy
The baseline average TSTwas 453.3 (60.0)
minutes, average SOL (latency) was 77.1
(44.8) minutes, average sleep efficiency
was 72.6% (8.7), average duration of
wake after sleep onset was 85.4 (45.1)
minutes, and the average number of
night wakenings was 21.2 (8.1). There
were no differences at baseline between
the 2 randomization groups (see Table 2).
TST (Primary Outcome)
There was no evidence of a period effect
for TST (t
52
= 0.996, P= .324). When
testing for differences between the
weighted blanket and control blanket by
looking at the within subject differences
in the outcome by sequence groups,
there was no significant difference (t
52
=
0.893, P= .376). For sequence group
weighted-control, the TST was only
slightly longer when using control com-
pared with weighted (mean difference
[weighted-control] = –0.7 [31.2]), and for
sequence group control-weighted, the
TST was slightly longer when using
FIGURE 2
CONSORT 2010 flow diagram. Participant flow through the study and reasons for dropout. T2, time 2; T4, time 4.
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control compared with weighted (mean
difference [control-weighted] = 7.7
[37.8]). This was confirmed by a paired
ttest comparing study blanket and
control blanket, irrespective of starting
group (t
53
= 0.896, P= .374). The mean
difference was –4.2 (34.5, 95% confi-
dence interval –13.6 to 5.2). Hence,
overall there was no significant differ-
ence in TST between the study blanket
and control blanket (see Table 3 for
details of primary and secondary sleep
outcomes).
Sleep Latency, Sleep Efficiency, and
Wake After Sleep Onset (Secondary
Outcomes)
Similarly there was no evidence of a
period effect, within subject differences
in the outcome by sequence groups, or
overall significant differences between
study and control blanket for sleep la-
tency, sleep efficiency, or measures of
wake after sleep onset (see Table 3 for
details).
Sleep Diary
The baseline average TST was 531.8
(109.6) min, average SOL (latency) was
70.0 (47.6), the average time of the night
wake was 16.7 (12.8), and the average
proportion of nights with at least 1 wake
was 0.30 (0.34). There were no differences
at baseline between the 2 randomization
groups (see Table 2).
In keeping with the actigraphy, there
was no evidence of a period effect,
within-subject differences in the out-
come by sequence groups, or overall
significant differences between study
and control blanket for TST, sleep la-
tency, measures of wake after sleep
onset, or parents’perception of per-
centage the blanket was worn each
night (see Table 3).
Questionnaire Outcomes
Table 4 summarizes the questionnaire
outcomes. The CSDI showed a clinically
small (0.74) but statistically significant
(P= .010) lower score (better sleep)
during the control blanket period.
There were no significant differences
for the total scores or subscales be-
tween the weighted blanket and the
control blanket for the SPBQ or ABC.
Table 5 summarizes results of the child
and parent scales used to assess per-
ceived sleep quality and blanket accept-
ability. More children chose the “really
liked”category for the weighted blanket
than control blanket (48% vs 31%). More
parents felt that sleep was “very much/
much improved”(51% vs 16%) and their
child calmer (35% vs 14%) with the
weighted blanket than control blanket.
Tolerability Outcomes
No serious adverse events were repor-
ted, and other thana 2-day skin rash on 1
child that may have been related to the
blanket,all others were unrelated illness
(eg, colds, fever, chicken pox, broken
bone in hand). No formal statistical tests
were undertaken, and the results for
each group appeared similar.
Exploratory Analyses
Results of exploratory analyses are
provided in Table 6. The treatment ef-
fect was not modified by age, weight,
baseline degree of sleep problems, SCQ
autism severity score, or initial sen-
sory profile on the SSPCQ.
DISCUSSION
In this randomized controlled CROS, a
weighted blanket intervention was found
to be no more effective than a control
(usual weight) blanket at improving TST
or any other commonly measured pa-
rameter of sleep quantity or quality. This
was regardless of whether parameters
were measured objectively by actigraphy
or subjectively with parent diaries. There
were no adverse events. Interestingly,
children were more likely to like the
weighted blanket and parents more
likely to rate their child’s sleep as better,
despite no actigraphy or diary evidence
TABLE 2 Comparison of Trial Groups on Primary and Secondary Sleep Variables at Baseline
Baseline Mean
(SD), n
Weighted Mean
(SD), n
Control Blanket
Mean (SD), n
Mean Difference (SD)
(Weighted-Control), n
t
df
,P(Weighted Versus
Control) Comparison
Actigraphy
TST, min 452.8 (59.7), 67 454.4 (62.4), 65 457.7 (64.6), 66 24.6 (33.3), 64 t
63
= 1.103, .274
SOL, min 76.5 (46.1), 60 74.3 (48.7), 59 69.9 (43.8), 59 1.4 (26.2), 57 t
56
= 0.390, .698
Sleep efficiency,
a
% 72.7 (8.8), 60 73.4 (9.3), 59 74.2 (7.8), 59 20.2 (4.5), 57 t
56
= 0.321, .749
No. of night wakenings 20.9 (8.0), 67 19.1 (6.7), 65 19.5 (6.9), 66 20.3 (3.1), 64 t
63
= 0.892, .376
Time awake after sleep onset 85.7 (44.7), 67 84.1 (43.1), 65 83.8 (41.4), 66 20.1 (26.5), 64 t
63
= 0.043, .966
Sleep diary
% of time blanket in place —75.6 (25.4), 67 73.7 (25.7), 67 1.9 (18.4), 67 t
63
= 0.813, .419
TST 531.8 (109.6), 67 528.9 (127.1), 67 513.0 (154.1), 67 15.9 (93.0), 67 t
66
= 1.398, .167
SOL, min 69.9 (47.6), 67 55.6 (37.8), 67 57.2 (42.8), 67 21.6 (20.9), 67 t
66
= 0.631, .531
Proportion of nights with $1 wake 0.3 (0.3), 66 0.2 (0.3), 67 0.2 (0.3), 67 20.01 (0.21), 67 t
66
= 0.460, .647
Average time awake 16.7 (12.9), 66 15.6 (13.4), 67 14.6 (13.3), 67 001 (11.7), 67 t
66
= 0.013, .989
a
Calculated as number of minutes spent sleeping in bed/total number of minutes spent in bed 3100.
*P,.05;
*** P,.001.
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to support this. Parents also rated their
child’sbehaviorascalmerwhenusing
the weighted blanket. It is possible these
findings are related to a perception of
improved sleep brought about by im-
proved bedtime behavior, positive attri-
butions about the intervention that
affected perceptions or parent child
interactions, or that parents were
influenced by a desire to please the
study team or reinforce widely held
beliefs about weighted blankets. It is
also possible that parents were aware
of some qualitative change in the child
that our measures did not capture.
The strengths of our design include (1)
the first randomized study specifically
designed and powered to assess the
impact of a weighted blanket on TST in
children with ASD, (2) the purposive in-
clusion of a “placebo”control, (3) the use
of an objective assessment of sleep,
(4) the inclusion of secondary out-
comes that included sensory and
other daytime behaviors, and (5) find-
ings generalizable to children diag-
nosed in community settings with ASD
and poor sleep.
Limitations include the following: (1)
the weighted blankets were obviously
heavier than the control blankets,
makingtrue masking of weighted versus
controlimpossible. This made a placebo
response more likely and was the main
reason we decided that subjective out-
comes such as sleep diaries would not
suffice, choosing instead actigraphy as
the most practical objective measure.
The run-in period helped maximize the
number of children who tolerated
actigraphy, and, in contrast to other
studies using the same methodology,
this technique provided robustobjective
primary outcome data across .95% of
the children recruited. (2) The parental
estimation of percentage of blanket
contact is likely to be extremely sub-
jective, and we acknowledge this, but we
believe it was important to have some
estimate of “adherence and concor-
dance”to treatment. If this study were
to be repeated, then concurrent in-
frared video would enable a more pre-
cise analysis. (3) Although the study
was powered to detect a 40-minute dif-
ference in TST with .63 patients, only
54 subjects were available for the
weighted blanket–control comparison.
The mean differences of ∼4 minutes,
however, were not significant, and an
additional 9 patients would not have
altered the study outcome. (4) This was
a pragmatic trial, thus we did not
TABLE 3 Sleep Outcomes
Baseline Mean
(SD), n
Weighted Blanket
Mean (SD), n
Control Blanket
Mean (SD), n
Mean Difference (SD)
Between Weighted and
Control Blanket, n
t
df
,Pof Weighted Versus
Control Comparison
Actigraphy
TST, min 453.3 (60.0), 62 452.8 (65.0), 57 455.4 (65.8), 62 24.2 (34.5), 54 t
53
= 0.896, .374
SOL, min 77.1 (44.8), 55 71.4 (48.2), 54 70.6 (44.3), 57 2.1 (26.8), 50 t
49
= 0.560, .578
Sleep efficiency,
a
% 72.6 (8.7), 55 73.6 (9.5), 54 74.2 (8.0), 57 20.3 (4.), 50 t
49
= 0.422, .675
No. of night wakenings 21.2 (8.1), 62 19.5 (7.0), 57 19.5 (6.8), 62 20.2 (3.2), 54 t
53
= 0.466, .643
Time awake after sleep onset 85.4 (45.1), 62 84.6 (42.6), 57 84.5 (41.5), 62 22.5 (25.6), 54 t
53
= 0.706, .483
Sleep diary
% of time blanket in place —75.6 (25.4), 67 73.7 (25.7), 67 1.9 (18.4), 67 t
66
= 0.813, .419
TST, min 531.8 (109.6), 67 528.9 (127.1), 67 513.0 (154.1), 67 15.9 (93.0), 67 t
66
= 1.398, .167
SOL, min 69.9 (47.6), 67 55.6 (37.8), 67 57.2 (42.8), 67 21.6 (20.9), 67 t
66
= 0.631, .531
Proportion of nights with $1 wake 0.3 (0.3), 66 0.2 (0.3), 67 0.2 (0.3), 67 20.01 (0.21), 67 t
66
= 0.460, .647
Average time awake 16.7 (12.9), 66 15.6 (13.4), 67 14.6 (13.3), 67 0.01 (11.67), 67 t
66
= 0.013, .989
a
Calculated as number of minutes spent sleeping in bed/total number of minutes spent in bed 3100.
TABLE 4 Questionnaire Outcomes
Baseline Mean
(SD), n
Weighted Blanket
Mean (SD), n
Control Blanket
Mean (SD), n
Mean Difference (SD)
Between Blanket
(Weighted-Control)
Wilcoxon Test P(Weighted
Versus Control) Comparison
CSDI scale 0–18 12.2 (2.1), 62 10.8 (2.3), 58 11.4 (2.0), 62 20.74 (2.3), 58 .010
ABC
Total score 58.4 (26.3), 65 47.6 (25.5), 67 48.4 (25.2), 64 22.3 (12.3), 64 .191
Irritability, agitation, crying (scale 0–45) 16.0 (9.6), 67 13.3 (8.6), 67 14.3 (10.2), 67 20.9 (4.7), 67 .173
Lethargy, social withdrawal (scale 0–48) 11.0 (6.8), 66 8.1 (6.6), 67 8.7 (6.8), 65 20.7 (3.2), 65 .087
Stereotypic behavior (scale 0–21) 5.3 (4.7), 66 4.4 (4.0), 67 4.6 (4.5), 67 20.2 (2.1), 67 .368
Hyperactivity, noncompliance (scale 0–48) 22.3 (10.3), 67 18.4 (9.2), 67 19.1 (9.5), 66 21.0 (5.4), 66 .159
Inappropriate speech (scale 0–12) 4.0 (2.8), 67 3.3 (3.1), 67 3.4 (3.0), 67 20.1 (1.4), 67 .882
SPBQ
Frequency 82.2 (21.3), 64 77.3 (21.3), 65 78.6 (22.7), 65 21.7 (10.7), 64 .186
Impact 66.5 (22.6), 64 61.0 (21.5), 66 64.1 (24.6), 64 23.3 (12.2), 64 .090
Total score 148.8 (42.4), 64 138.6 (41.3), 65 142.4 (46.2), 64 24.9 (21.1), 63 .115
304 GRINGRAS et al by guest on December 23, 2020www.aappublications.org/newsDownloaded from
exclude children who were on stable
medications and constant doses. It is
possible that some of these medications
could have altered sleep parameters.
However, the randomized crossover de-
sign means any effect would be present
during both arms. Baseline data show
that no child was on medication that was
“normalizing”sleep, and all subjects had
sufficientlypoorTSTstoleaveroomfor
improvement.
Weighted blankets are widely available
commercially, and anecdotal reports
promote their use in children with ASD.
The blankets will cost families in ex-
cess of £100/115EU/$150 and cannot
be returned to manufacturers if they
are not effective. Our findings pro-
vide valuable evidence that although
weighted blankets in children with
ASD are safe and well perceived by
child and parent alike, there is no
measurable evidence they are bene-
ficial for children’ssleep.
ACKNOWLEDGMENTS
The Snuggledown Group acknowledges
the support from our funders, Research
Autism, the Waterloo Foundation, and the
Baily Thomas Charitable Foundation. The
group also expresses its gratitude to the
children and families who participated in
this study and the schools that kindly
hosted interviews: Milestone School,
Hawkedown Primary School, Alexandra
Infant School, and Sonning Primary
School. Finally, thank you to Rachael Fal-
lows for concept planning and Dr Sri Gada
for his help with recruitment of families.
This study was supported by the United
Kingdom Clinical Research Collabora-
tion-registered King’s Clinical Trials Unit
at King’s Health Partners, which is in part
funded by the NIHR Biomedical Research
Centre for Mental Health at South London
and Maudsley NHS Foundation Trust and
TABLE 5 Child and Parent Opinions
Questions Weighted Blanket Control Blanket Wilcoxon Signed-Rank
Test (TS, n,P)
n%n%
Child’s quality of sleep: Which best describes how you have felt
about your sleep over the past 2 weeks?
Smiley face 28 56 17 35 1.746, 44, 0.081
Neutral face 15 30 23 47
Unhappy face 7 14 9 18
Children’s blanket scale: Which best describes how you have felt
about the blue blanket you have been using over the past 2
weeks?
Really liked the blanket 25 48 16 31 1.60, 48, .110
Blanket was just OK 19 37 20 39
Really disliked the blanket 8 15 15 29
Parent’s blanket scale: Compared with before the trial when child
was not using any special sensory blanket, my child’s sleep is:
Very much improved 10 15 1 1 4.763, 67, ,.001
Much improved 24 36 10 15
Minimally improved 21 31 16 24
No change 9 13 33 49
Minimally worse 2 3 4 6
Much worse 1 1 3 4
Very much worse 0 0 0 0
Parent’s blanket scale: Compared with before the trial when my
child was not using any special sensory blanket, if my child
woke at night, he or she seemed:
More agitated (screaming, distressed, scared) 0 0 3 5 2.089, 65, .037
No different from usual 29 44 41 62
Calmer (happier and more content) 23 35 9 14
Not applicable as so few awakenings 14 21 13 20
TS, test statistic.
TABLE 6 Results of Exploratory Analyses
Weighted
Blanket (TST)
Control
Blanket (TST)
Differences Between
Groups
Mean (SD) nMean (SD) n
SCQ threshold
SCQ ,15 448.6 (53.2) 7 468.3 (55.4) 6 F
1
= 1.551, P= .218
SCQ $15 465.7 (58.3) 25 439.4 (60.8) 29
SCQ ,11 431.8 (76.3) 4 445.0 (73.5) 2 F
1
= 0.423, P= .518
SCQ $11 466.3 (56.2) 28 444.4 (60.6) 33
SSPCQ threshold
Typical —396.0 (—)1
F
1
= 1.205, P= .277Probable 458.3 (64.0) 3 426.3 (74) 3
Definite 462.3 (59.4) 29 447.7 (60.1) 31
ARTICLE
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King’s College London and the NIHR Evalua-
tion, Trials and Studies Coordinating Centre.
Toaccess the full trialprotocol,please go
to: http://researchautism.net/pages/
research_autism_projects_studies/
research_autism_project_028
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(Continued from first page)
This trial has been registered with the ISRCTN Register (http://isrctn.org) (identifier ISRCTN05534585).
www.pediatrics.org/cgi/doi/10.1542/peds.2013-4285
doi:10.1542/peds.2013-4285
Accepted for publication Apr 30, 2014
Address correspondence to Paul Gringras, MBChB, MRCP, MsC, Evelina Children’s Hospital, St Thomas’Hospital, Lambeth Palace Rd, London, SE1 7EH, United Kingdom.
E-mail: paul.gringras@gstt.nhs.uk
PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275).
Copyright © 2014 by the American Academy of Pediatrics
FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose.
FUNDING: Supported by Research Autism, the Waterloo Foundation, and the Baily Thomas Charitable Foundation.
POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose.
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