Weighted Blankets and Sleep in AutisticChildren—A Randomized Controlled Trial

WHAT’S KNOWN ON THIS SUBJECT: Children with autism sleeppoorly compared with their peers. Sensory integration, includinguse of weighted blankets, is proposed as a means to reducearousal and stress. There is, however, no evidence that weightedblankets can improve sleep for these children.

WHAT THIS STUDY ADDS: This is the first robust study to evaluatethe impact of weighted blankets and show that they do notimprove sleep parameters in children with autism spectrumdisorder.

abstractOBJECTIVE: To assess the effectiveness of a weighted-blanket interven-tion in treating severe sleep problems in children with autism spectrumdisorder (ASD).

METHODS: This phase III trial was a randomized, placebo-controlledcrossover design. Participants were aged between 5 years and 16 years10 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 identicalusual weight blanket (control), introduced at bedtime; each was usedfor a 2-week period before crossover to the other blanket. Primary out-come was total sleep time (TST) recorded by actigraphy over each 2-weekperiod. Secondary outcomes included actigraphically recorded sleep-onset latency, sleep efficiency, assessments of child behavior, familyfunctioning, and adverse events. Sleep was also measured by usingparent-report diaries.

RESULTS: Seventy-three children were randomized and analysisconducted on 67 children who completed the study. Using objectivemeasures, the weighted blanket, compared with the control blanket,did not increase TST as measured by actigraphy and adjusted forbaseline TST. There were no group differences in any other objectiveor subjective measure of sleep, including behavioral outcomes. Onsubjective preference measures, parents and children favored theweighted blanket.

CONCLUSIONS: The use of a weighted blanket did not help childrenwith ASD sleep for a longer period of time, fall asleep significantlyfaster, or wake less often. However, the weighted blanket was favoredby children and parents, and blankets were well tolerated over thisperiod. 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 DanielleMoore,c Zenobia Zaiwalla,e and Luci Wiggs, DPhil,CPsychold

aChildren’s Sleep Medicine, Evelina London Children’s Hospital,St Thomas’ Hospital, London, United Kingdom; bCentre forRehabilitation and dDepartment of Psychology, Oxford BrookesUniversity, Oxford, United Kingdom; cLime Trees Child and FamilyUnit, York, England; and eDepartment of Clinical Neurophysiology,John Radcliffe Hospital, Oxford, United Kingdom

KEY WORDSautism spectrum disorder, severe sleep problems, weightedblankets, total sleep time, children

ABBREVIATIONSABC—Aberrant Behavior ChecklistASD—autism spectrum disorderCONSORT—Consolidated Standards of Reporting TrialsCROS—crossover analysisCSDI—Composite Sleep Disturbance IndexSCQ—Social Communication QuestionnaireSOL—sleep onset latencySSPCQ—Short Sensory Profile Caregiver QuestionnaireTST—total sleep time

Professor Gringras was involved in the design of the study, thefunding application, development of the protocol, andrecruitment of patients as a local principal investigator; wasco–chief investigator for the trial and a member of the trialmanagement group; and cowrote the article; Dr Wiggscontributed to the design of the study, the funding application,and development of the protocol; advised on the use ofactigraphy and patient-reported outcomes; was principalinvestigator and co–chief investigator for the trial; wasa member of the trial management group; and helped write thearticle; Ms Rush coordinated the trial, recruited patients, scoredactigraphy, helped write the article, and was a member of thetrial management group; Ms Sparrowhawk and Ms Prattrecruited patients, helped write the article, and were membersof the trial management group; Dr Wright helped recruitpatients and coordinate the trial, helped write the article, wasco–principal investigator for the trial, and was a member of thetrial management group; Ms Hooke and Ms Moore helpedrecruit patients, respond to family queries, and collect andrecord data; Dr Allgar helped with the statistical analysis plan,analyzing data, and writing the article; Dr Green contributed tothe design of the study, the funding application and ethicalsubmission, advised on the use of sensory questionnaires andpatient reported outcomes, helped write the article, and wasa member of the trial management group; and Dr Zaiwallahelped with the initial study design and recruitment as leadclinician from the Oxford Group and helped write the article.

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Children with autism spectrum disorder(ASD) are more likely to have disturbedsleep than typically developing children,with a prevalence of sleepdisturbance inchildren with ASD between 40% and80%.1 The most commonly reportedsleep disturbances are increased sleeplatency (time to fall asleep) and frequentnight waking, which result in reducedsleep duration.2 The etiology of sleepdisorders in ASD is poorly understood.3

Sleeping difficulties are frequentlychronic, resulting in additional learningand behavior problems4 and affectingthe whole family’s well-being. Behavioralinterventions work with some children,but not all.5 Pharmacological inter-ventions, with exogenous melatonin, haveshownpotential for reducing sleep latencyby∼30minutes but have a less significantimpact on total sleep time (TST).6,7

Weighted blankets are often recommen-dedbyprofessionalswhoworkwithyoungpeoplewithASDtoassistwithcalmingandrelaxation, as well as to assist withsleeping.8,9 The theory underlying thereasons for using weighted blankets andother weighted items for calming pur-poses is based on sensory integration.10 Itis hypothesized that the deep pressureand more consistent sensory input pro-vided by weighted items reduces thebody’s physiologic level of arousal andstress, which might improve sleep. Al-though weighted blankets potentially of-fer a relatively cheap, nonpharmacologicintervention, research on their efficacy inchildren with ASD is lacking. This trialwas therefore conceived to establishwhether this novel intervention could in-crease TST and improve other sleepparameters in children with ASD.

METHODS

Study Design and Oversight

This randomized,multicenter, controlled,crossover phase III trial was undertakenin 3 sites in England. The study was ap-proved through the UK Integrated Re-search Application System and the

reviewboardofeachparticipatingcenterand was conducted in accordance withthe International Conference on Harmo-nization Good Clinical Practice Guidelinesand the Declaration of Helsinki. Writteninformed consent was obtained from thelegal guardians of the children. Informedwritten assent was also obtained fromcompetent study participants between 8and 16 years of age.

Study Population

Children were eligible to participate ifthey were aged between 5 years and 16years 10 months and had an ASD di-agnosis and if their parents reportedasleepproblem(asdefined later), foratleast the previous 5 months. The di-agnosis of ASD was reached if clinicalrecords fromthe localmultidisciplinaryteam agreed to an unequivocal ASDdiagnosis including autism, Aspergersyndrome, or pervasive developmentaldisorder not otherwise specified. Inaddition to consideration of schoolreports and direct observations, theseteams used a range of standardizeddiagnostic instruments reflectingusualASD diagnostic practice in the UnitedKingdom.11,12 Sleep problems werecharacterized as failing to fall asleepwithin 1 hour of “lights off” on 3 of5 nights and/or achieving ,7 hours ofcontinuous sleep on 3 of 5 nights. Chil-dren were not included if they wereknown to suffer from obstructive sleepapnea, night terrors, or other disorderslikely to have an impact on sleep. Twoamendments were made to the eligibilitycriteria after trial commencement: theage for inclusion was raised by 1 year to16 years 10 months, and patients ona stable dose of permittedmedication for.6monthswere included (see protocol).These changes were to maximize re-cruitment without affecting trial fidelity.

Intervention

A number of commercially availableweighted blankets in common use that

adhered to the original guidance on sen-sory interventions as proposed by Ayres10

(providing constant proprioceptive stim-ulation distributed across the body) wereconsidered by the senior occupationaltherapist of this study (DG). A specificweighted blanket used in the UnitedStates and United Kingdom was chosen.The weighted blanket weighed 2.25 kg(small) or 4.5 kg (large) and was heavywithout being thick (and therefore toowarm) through the use of 3-mmsteel shotpellets embedded evenly throughout theblanket. Although we were aware thatblinding child and parent to the differentweights of study and control blanket wasimpossible, we matched the controlblankets by size, color, and texture of thematerial. Some children with ASD duringpilot stages were aware of the subtletexture of the weighted blankets’ steelshot, and so we commissioned the sup-pliers to incorporate lightweight plasticbeads identical in size to the steel shotinto the bespoke control blankets.

Twosizesofblankets (small: 147376cm;large: 152 3 152 cm) according to thesize of child were used, consistent withrecommendations by manufactures andtherapists.

Procedures

After screening and consent, eligibleparticipants began a baseline adapta-tion and monitoring period of 7 to 21days.

During treatment phases, each blanketwasusedfor12to16days,withactigraphyand sleep diarymonitoring. After the firsttreatment phase, the researchers re-moved the initial blanket, diaries, andactigraph and provided the next blanket,actigraph, and new sleep diaries. Carewas taken to ensure that the baseline andintervention phases were conductedduring school-term time and that nobreaks occurred between interventions(avoiding school holiday periods, for ex-ample). All interviews and data collectionwere carried out by the researchers and

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visits took place in clinic, within desig-nated schools, or whenever possible, thepatients’ homes.

Randomization

Remote randomizationwas carried out byKings Clinical Trial Unit by using blockrandomizationwithrandomvariableblocklengths of 2 and 4, and stratifiedby center.Randomization requests were generatedby the researchers, who then dispensedthe allocated treatments. Because of thenatureof the treatment, researcherswereunblinded; however, all trial investigators(PG, DG, LW, BW) and the statistician (VA)were blind to treatment allocationthroughout the trial and analysis.

Measuring Sleep

The trial design included both objective(actigraphy) and subjective (parent-completed diary) measures of sleep asrecommended by Sadeh.13 There arebenefits with each approach and alsoreasons the results may not be concor-dant14,15; for example, sleep diarieswouldnot detect periods when the child wasawake but not disturb the household (aparticular concern for determining sleeponset latency [SOL]), and actigraphy mayinterpret restless sleep as being awake.

The actigraph (Micro Mini Motionlog-ger, Ambulatory Monitoring, Ardsley,NY), an accelerometer, wasworn on thenondominantwrist, andmovementwasmonitored continuously and storedwithin the unit. Subsequent analysis offrequency and pattern of movement bymeans of validated algorithms permitsdetection of basic sleep–wake pat-terns.13 Movements were scored in1-minute epochs; all epochs that arescored above a preset threshold usingan algorithm by Sadeh13 are scored as“awake” and those that are below thisthreshold are scored as “sleep.”

Study Outcomes

Various assessments of sleep parame-ters,sensoryprofiles,daytimebehaviors,

and perceptions of blanket use wereconductedatdifferenttimepoints(Table1).

The primary outcomewas TST,measuredby actigraphy. Aminimumof 5 of 7 nights’actigraphy data (or $71% if .7 nightswere captured) was required at baselineand during each blanket phase, andaverages were calculated at each timepoint. Children not meeting this re-quirement were excluded from the dataanalyses of themain research questions.

Secondary sleep outcomes included TSTmeasured by parental diary; SOL mea-suredbydiariesandactigraphy; andsleepefficiency (the proportion of time spent inbed asleep) measured by actigraphy.

Three questionnaires were completed atbaseline and at the end of both in-tervention periods: the Composite SleepDisturbance Index (CSDI; frequency andduration of sleep problems),16–18 theAberrant Behavior Checklist (ABC; to as-sess behavioral problems),19,20 and theSensory Behavior Questionnaire (SBQ;sensory stimuli response profile).21

Three questionnaires were only com-pleted at baseline: the Children’s SleepHabits Questionnaire (a parent-reportvalidated sleep screening instrument),the Social Communication Questionnaire(SCQ; a screening instrument for ASD),22

and the Short Sensory Profile CaregiverQuestionnaire (SSPCQ; a questionnaireto establish a profile of children’s sen-sory responses).23 The trial flowchartcan be seen in Fig 1.

Children and parents also completedsubjective ratings of sleep quality andacceptabilityof theblanket.Thesleepdiarycontainedasectionforparentstoestimatethepercentageofthenighttheblanketwasin contact with the child’s body.

The frequency and severity of adverseevents were monitored carefully througha 24-hour telephone number and weeklyparentreviews(face-to-faceor telephone).

Statistical Considerations

The “intention to treat” principle wasused throughout, with analyses un-dertaken by using SPSS (version 20; SASInstitute, Cary, NC).24 Missing data forquestionnaire responses were proratedif ,10% was missing, and data wereexcluded otherwise.

The TST primary outcome (actigraphy)was analyzed by taking the average TSTover baseline and each of the 2-weekintervention periods. It was powered at80% with a 5% significance level todetect a change from baseline of 40minutes between the study blanket andplacebo blanket periods using a com-mon SD of 1.7.24,25 Allowing for 20%missing data based on pilot work, 63 intotal were required.

The actigraphy data and sleep diaryoutcomes were analyzed by taking theaverage TST (actigraphy and diary) andaverageSOL(actigraphyanddiary)overthe baseline and each of the 2-weekintervention 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), 6–32ASD diagnosis, n (%)Autism 8 (25) 13 (37)Asperger syndrome 16 (50) 17 (49)ASD 8 (25) 5 (14)

Sensory profile (Dunn23) 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 undertakenbetween the randomization groups,withmean (SD) or median (interquartilerange) for continuous data and n (%) forcategorical data. No statistical testswere used to compare baseline data(Consolidated Standards of ReportingTrials [CONSORT]; http://www.consort-statement.org/downloads).

The primary analysis was to compareTSTwhenusingweightedblanketversuscontrol blanket (actigraphy). To rule outa period effect, a crossover analysis(CROS) was undertaken. The sum of theTST values was calculated for the timeperiod when using weighted blanketandwhenusingcontrolblanket foreachsubject. This was compared across thesequence groups by means of an in-dependent t test. Where the test wasnot significant, this indicated that therewas no evidence of a period effect.26

The second stage of CROS is to test thedifference between the weighted blanketand the control blanket. The differences inthe TST were calculated between the firstperiod and the second period, and thisdifference was compared across the se-quence groups by means of an in-dependent t test. This method of analysisadjusts for the period effect and soreduces the effect of any period difference.

This was then followed by the more con-ventional analysis of a CROS by usinga paired t test to compare TSTwhen usingweighted blanket versus TST when usingcontrol blanket, whichwas irrespective ofstarting group. The existence of cross-over effects must be ruled out before thismethod is valid (see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3345345).

The same statistical procedures werefollowed for secondary sleep data. Fordata from the SPBQ, ABC, and CSDI,

a CROS was again undertaken, by usingMann-Whitney tests to examine thecrossover effect. A Wilcoxon paired testwas then used to compare the studyblanket and control blanket scores,irrespective of starting groupwhere theexistence of crossover effects was ruledout. Exploratory analysis of sensoryinfluencesonTST inresponsetoblanketswas undertaken by using repeated-measures analysis of variance.23

All analyses were performed on SPSS(version 20; IBM SPSS Statistics, IBMCorporation). P , .05 was consideredto indicate statistical significance.

RESULTS

Seventy-three children were recruitedand followed up between August 2011and October 2012.

The CONSORT diagram in Fig 2 shows thescreening, randomization, and follow-up

FIGURE 1Trial flowchart. T, time.

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of the patients. Baseline characteristicswere similar betweengroups (see Table 1).

Seventy-three patients were random-ized, and 6 were subsequently excluded.Fourcouldnot tolerateordeclinedtousethe weighted blanket, 1 chose to with-drawtoattendanalternativeclinic,and1had an unrelated illness and could notcontinue. The baseline characteristics ofthe 2 groups can be seen in Table 1.

It is interesting to note that despiteagreed ASD diagnoses from multidisci-plinary teams, 13 (19%) were not abovethe recommended cutoff of 15 on theSCQ,butof these11wereabove thecutoff

of 11 discussed in the review by Norrisand Lecavalier27 as the cutoff withmaximum sensitivity and specificity.

Sleep Outcomes

Actigraphy

ThebaselineaverageTSTwas453.3 (60.0)minutes, average SOL (latency) was 77.1(44.8) minutes, average sleep efficiencywas 72.6% (8.7), average duration ofwake after sleep onset was 85.4 (45.1)minutes, and the average number ofnight wakenings was 21.2 (8.1). Therewere no differences at baseline betweenthe2 randomizationgroups (see Table 2).

TST (Primary Outcome)

There was no evidence of a period effectfor TST (t52 = 0.996, P = .324). Whentesting for differences between theweighted blanket and control blanket bylooking at the within subject differencesin the outcome by sequence groups,there was no significant difference (t52 =0.893, P = .376). For sequence groupweighted-control, the TST was onlyslightly longer when using control com-pared with weighted (mean difference[weighted-control] = –0.7 [31.2]), and forsequence group control-weighted, theTST was slightly longer when using

FIGURE 2CONSORT 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 (meandifference [control-weighted] = 7.7[37.8]). This was confirmed by a pairedt test comparing study blanket andcontrol blanket, irrespective of startinggroup (t53 = 0.896, P = .374). The meandifference 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 blanketand control blanket (see Table 3 fordetails of primary and secondary sleepoutcomes).

Sleep Latency, Sleep Efficiency, andWake After Sleep Onset (SecondaryOutcomes)

Similarly there was no evidence of aperiod effect, within subject differencesin the outcome by sequence groups, oroverall significant differences betweenstudy and control blanket for sleep la-tency, sleep efficiency, or measures ofwake after sleep onset (see Table 3 fordetails).

Sleep Diary

The baseline average TST was 531.8(109.6) min, average SOL (latency) was70.0 (47.6), the average time of the nightwake was 16.7 (12.8), and the averageproportion of nights with at least 1 wakewas0.30(0.34).Therewerenodifferences

at baseline between the 2 randomizationgroups (see Table 2).

In keeping with the actigraphy, therewas no evidence of a period effect,within-subject differences in the out-come by sequence groups, or overallsignificant differences between studyand control blanket for TST, sleep la-tency, measures of wake after sleeponset, or parents’ perception of per-centage the blanket was worn eachnight (see Table 3).

Questionnaire Outcomes

Table 4 summarizes the questionnaireoutcomes. The CSDI showed a clinicallysmall (0.74) but statistically significant(P = .010) lower score (better sleep)during the control blanket period.There were no significant differencesfor the total scores or subscales be-tween the weighted blanket and thecontrol blanket for the SPBQ or ABC.

Table 5 summarizes results of the childand parent scales used to assess per-ceived sleep quality and blanket accept-ability. More children chose the “reallyliked” category for the weighted blanketthan control blanket (48% vs 31%). Moreparents felt that sleep was “very much/much improved” (51% vs 16%) and theirchild calmer (35% vs 14%) with theweighted blanket than control blanket.

Tolerability Outcomes

No serious adverse events were repor-ted, andother thana2-day skin rashon1child that may have been related to theblanket,allotherswereunrelated illness(eg, colds, fever, chicken pox, brokenbone in hand). No formal statistical testswere undertaken, and the results foreach group appeared similar.

Exploratory Analyses

Results of exploratory analyses areprovided in Table 6. The treatment ef-fect was not modified by age, weight,baseline degree of sleep problems, SCQautism severity score, or initial sen-sory profile on the SSPCQ.

DISCUSSION

In this randomized controlled CROS, aweighted blanket interventionwas foundto be no more effective than a control(usual weight) blanket at improving TSTor any other commonly measured pa-rameter of sleep quantity or quality. Thiswas regardless of whether parametersweremeasuredobjectively byactigraphyor subjectivelywith parent diaries. Therewere no adverse events. Interestingly,children were more likely to like theweighted blanket and parents morelikely 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 BlanketMean (SD), n

Mean Difference (SD)(Weighted-Control), n

tdf, P (Weighted VersusControl) Comparison

ActigraphyTST, min 452.8 (59.7), 67 454.4 (62.4), 65 457.7 (64.6), 66 24.6 (33.3), 64 t63 = 1.103, .274SOL, min 76.5 (46.1), 60 74.3 (48.7), 59 69.9 (43.8), 59 1.4 (26.2), 57 t56 = 0.390, .698Sleep efficiency,a % 72.7 (8.8), 60 73.4 (9.3), 59 74.2 (7.8), 59 20.2 (4.5), 57 t56 = 0.321, .749No. of night wakenings 20.9 (8.0), 67 19.1 (6.7), 65 19.5 (6.9), 66 20.3 (3.1), 64 t63 = 0.892, .376Time awake after sleep onset 85.7 (44.7), 67 84.1 (43.1), 65 83.8 (41.4), 66 20.1 (26.5), 64 t63 = 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 t63 = 0.813, .419TST 531.8 (109.6), 67 528.9 (127.1), 67 513.0 (154.1), 67 15.9 (93.0), 67 t66 = 1.398, .167SOL, min 69.9 (47.6), 67 55.6 (37.8), 67 57.2 (42.8), 67 21.6 (20.9), 67 t66 = 0.631, .531Proportion 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 t66 = 0.460, .647Average time awake 16.7 (12.9), 66 15.6 (13.4), 67 14.6 (13.3), 67 001 (11.7), 67 t66 = 0.013, .989

a Calculated as number of minutes spent sleeping in bed/total number of minutes spent in bed 3 100.* P , .05;*** P , .001.

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to support this. Parents also rated theirchild’s behavior as calmer when usingthe weighted blanket. It is possible thesefindings are related to a perception ofimproved sleep brought about by im-proved bedtime behavior, positive attri-butions about the intervention thataffected perceptions or parent childinteractions, or that parents wereinfluenced by a desire to please thestudy team or reinforce widely heldbeliefs about weighted blankets. It isalso possible that parents were awareof some qualitative change in the childthat our measures did not capture.

The strengths of our design include (1)the first randomized study specificallydesigned and powered to assess theimpact of a weighted blanket on TST inchildren 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 andother daytime behaviors, and (5) find-ings generalizable to children diag-nosed in community settings with ASDand poor sleep.

Limitations include the following: (1)the weighted blankets were obviouslyheavier than the control blankets,making truemaskingofweightedversuscontrol impossible. This made a placeboresponse more likely and was the mainreason we decided that subjective out-comes such as sleep diaries would notsuffice, choosing instead actigraphy asthe most practical objective measure.The run-in period helped maximize thenumber of children who toleratedactigraphy, and, in contrast to otherstudies using the same methodology,

this technique provided robust objectiveprimary outcome data across.95% ofthe children recruited. (2) The parentalestimation of percentage of blanketcontact is likely to be extremely sub-jective, andwe acknowledge this, but webelieve it was important to have someestimate of “adherence and concor-dance” to treatment. If this study wereto be repeated, then concurrent in-frared video would enable a more pre-cise analysis. (3) Although the studywas powered to detect a 40-minute dif-ference in TST with .63 patients, only54 subjects were available for theweighted blanket–control comparison.The mean differences of ∼4 minutes,however, were not significant, and anadditional 9 patients would not havealtered the study outcome. (4) This wasa pragmatic trial, thus we did not

TABLE 3 Sleep Outcomes

Baseline Mean(SD), n

Weighted BlanketMean (SD), n

Control BlanketMean (SD), n

Mean Difference (SD)Between Weighted andControl Blanket, n

tdf, P of Weighted VersusControl Comparison

ActigraphyTST, min 453.3 (60.0), 62 452.8 (65.0), 57 455.4 (65.8), 62 24.2 (34.5), 54 t53 = 0.896, .374SOL, min 77.1 (44.8), 55 71.4 (48.2), 54 70.6 (44.3), 57 2.1 (26.8), 50 t49 = 0.560, .578Sleep efficiency,a % 72.6 (8.7), 55 73.6 (9.5), 54 74.2 (8.0), 57 20.3 (4.), 50 t49 = 0.422, .675No. of night wakenings 21.2 (8.1), 62 19.5 (7.0), 57 19.5 (6.8), 62 20.2 (3.2), 54 t53 = 0.466, .643Time awake after sleep onset 85.4 (45.1), 62 84.6 (42.6), 57 84.5 (41.5), 62 22.5 (25.6), 54 t53 = 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 t66 = 0.813, .419TST, min 531.8 (109.6), 67 528.9 (127.1), 67 513.0 (154.1), 67 15.9 (93.0), 67 t66 = 1.398, .167SOL, min 69.9 (47.6), 67 55.6 (37.8), 67 57.2 (42.8), 67 21.6 (20.9), 67 t66 = 0.631, .531Proportion 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 t66 = 0.460, .647Average time awake 16.7 (12.9), 66 15.6 (13.4), 67 14.6 (13.3), 67 0.01 (11.67), 67 t66 = 0.013, .989

a Calculated as number of minutes spent sleeping in bed/total number of minutes spent in bed 3 100.

TABLE 4 Questionnaire Outcomes

Baseline Mean(SD), n

Weighted BlanketMean (SD), n

Control BlanketMean (SD), n

Mean Difference (SD)Between Blanket(Weighted-Control)

Wilcoxon Test P (WeightedVersus 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 .010ABCTotal score 58.4 (26.3), 65 47.6 (25.5), 67 48.4 (25.2), 64 22.3 (12.3), 64 .191Irritability, 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 .173Lethargy, 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 .087Stereotypic behavior (scale 0–21) 5.3 (4.7), 66 4.4 (4.0), 67 4.6 (4.5), 67 20.2 (2.1), 67 .368Hyperactivity, noncompliance (scale 0–48) 22.3 (10.3), 67 18.4 (9.2), 67 19.1 (9.5), 66 21.0 (5.4), 66 .159Inappropriate 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

SPBQFrequency 82.2 (21.3), 64 77.3 (21.3), 65 78.6 (22.7), 65 21.7 (10.7), 64 .186Impact 66.5 (22.6), 64 61.0 (21.5), 66 64.1 (24.6), 64 23.3 (12.2), 64 .090Total score 148.8 (42.4), 64 138.6 (41.3), 65 142.4 (46.2), 64 24.9 (21.1), 63 .115

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exclude children who were on stablemedications and constant doses. It ispossible that some of these medicationscould have altered sleep parameters.However, the randomized crossover de-sign means any effect would be presentduring both arms. Baseline data showthat no childwas onmedication thatwas“normalizing” sleep, and all subjects hadsufficiently poor TSTs to leave room forimprovement.

Weighted blankets arewidely availablecommercially, and anecdotal reportspromote their use in childrenwith ASD.The blankets will cost families in ex-cess of £100/115EU/$150 and cannotbe returned to manufacturers if theyare not effective. Our findings pro-vide valuable evidence that althoughweighted blankets in children withASD are safe and well perceived bychild and parent alike, there is no

measurable evidence they are bene-ficial for children’s sleep.

ACKNOWLEDGMENTSThe Snuggledown Group acknowledgesthe support from our funders, ResearchAutism, theWaterloo Foundation, and theBaily Thomas Charitable Foundation. Thegroup also expresses its gratitude to thechildren and familieswhoparticipated inthis study and the schools that kindlyhosted interviews: Milestone School,Hawkedown Primary School, AlexandraInfant School, and Sonning PrimarySchool. Finally, thank you to Rachael Fal-lowsforconceptplanningandDrSriGadafor his help with recruitment of families.

This study was supported by the UnitedKingdom Clinical Research Collabora-tion-registered King’s Clinical Trials Unitat King’s Health Partners, which is in partfunded by the NIHR Biomedical ResearchCentre forMental Health at South Londonand Maudsley NHS Foundation Trust and

TABLE 5 Child and Parent Opinions

Questions Weighted Blanket Control Blanket Wilcoxon Signed-RankTest (TS, n, P)

n % n %

Child’s quality of sleep: Which best describes how you have feltabout your sleep over the past 2 weeks?Smiley face 28 56 17 35 1.746, 44, 0.081Neutral face 15 30 23 47Unhappy face 7 14 9 18

Children’s blanket scale: Which best describes how you have feltabout the blue blanket you have been using over the past 2weeks?Really liked the blanket 25 48 16 31 1.60, 48, .110Blanket was just OK 19 37 20 39Really disliked the blanket 8 15 15 29

Parent’s blanket scale: Compared with before the trial when childwas not using any special sensory blanket, my child’s sleep is:Very much improved 10 15 1 1 4.763, 67, ,.001Much improved 24 36 10 15Minimally improved 21 31 16 24No change 9 13 33 49Minimally worse 2 3 4 6Much worse 1 1 3 4Very much worse 0 0 0 0

Parent’s blanket scale: Compared with before the trial when mychild was not using any special sensory blanket, if my childwoke at night, he or she seemed:More agitated (screaming, distressed, scared) 0 0 3 5 2.089, 65, .037No different from usual 29 44 41 62Calmer (happier and more content) 23 35 9 14Not applicable as so few awakenings 14 21 13 20

TS, test statistic.

TABLE 6 Results of Exploratory Analyses

WeightedBlanket (TST)

ControlBlanket (TST)

Differences BetweenGroups

Mean (SD) n Mean (SD) n

SCQ thresholdSCQ ,15 448.6 (53.2) 7 468.3 (55.4) 6

F1 = 1.551, P = .218SCQ $15 465.7 (58.3) 25 439.4 (60.8) 29SCQ ,11 431.8 (76.3) 4 445.0 (73.5) 2

F1 = 0.423, P = .518SCQ $11 466.3 (56.2) 28 444.4 (60.6) 33

SSPCQ thresholdTypical — 396.0 (—) 1

F1 = 1.205, P = .277Probable 458.3 (64.0) 3 426.3 (74) 3Definite 462.3 (59.4) 29 447.7 (60.1) 31

ARTICLE

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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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