Autism (2018)

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THEPREVALENCEOFAUTISTICTRAITSINAHOMELESSPOPULATION

AlasdairChurchard,MoragRyder,AndrewGreenhill,WilliamMandy

ABSTRACT

Anecdotalevidencesuggeststhatautisticpeopleexperienceanelevatedriskofhomelessness,

butsystematicempiricalresearchonthistopicislacking.Asasteptowardsfillingthisgapin

knowledge,weconductedapreliminaryinvestigationoftheprevalenceofDSM-5autism

symptomsinagroupoflong-termhomelesspeople.Theentirecaseload(N=106)ofaUK

homelessoutreachteamwasscreened(excludingindividualsbornoutsideoftheUKorRepublic

ofIreland)usinganin-depth,semi-structuredinterviewwithkeyworkers,basedonDSM-5

diagnosticcriteria.Thisshowedadequateinter-raterreliability,aswellasevidenceofcriterion

andconstructvalidity.Ofthesample,13people(12.3%,95%CI[7.0,20.4])screenedpositive,

meetingDSM-5autismcriteriabykeyworkerreport.Afurtherninepeople(8.5%,95%CI[4.5,

15.3])were‘marginal’,havingautistictraitsthatwerenotquitesufficienttomeetDSM-5

criteria.Thosewithelevatedautistictraits,comparedtothosewithout,tendedtobemore

sociallyisolated,andlesslikelytousesubstances.Thisstudyhasprovidedinitialevidencethat

autistictraitsareover-representedamonghomelesspeople;andthatautistichomelesspeople

mayshowadistinctpatternofcharacteristicsandneeds.Furtherinvestigationisrequiredto

buildupontheseprovisionalfindings.

Keywords:autism;homelessness;adults

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THEPREVALENCEOFAUTISTICTRAITSINAHOMELESSPOPULATION

Autismisaneurodevelopmentalconditioncharacterisedbydifficultieswithsocialrelating,social

communication,flexibilityandsensoryprocessing(AmericanPsychiatricAssociation[APA],

2013)1.Itoccursinapproximatelyonepercentofthepopulation,andpersistsacrossthelifespan

(Brughaetal.,2016).Autismisadimensionalcondition,representingoneendofacontinuumof

traitsthatextendsthroughoutthegeneralpopulation(Robinsonetal.,2017).Arealistic

understandingofautismshouldnotonlyfocusonthedifficultiesarisingfromthecondition,but

mustalsoincludeconsiderationofthestrengthsofautisticpeople.Forexample,themajorityof

autisticpeoplediagnosedaccordingtocurrentconventionshavefluentlanguageandanIQin

thenormalrange(Loomesetal.,2017;CentresforDiseaseControl,2014).Furthermore,many

havecapacitiesthatstemdirectlyfromtheirautism(e.g.,Howlinetal.,2009;Meilleur,Jelenic&

Mottron,2015;Soulières,Dawson,Gernsbacher&Mottrom,2011).

Despitetheirautism-relatedstrengths,andthefactthatmanyautisticpeopleleadsatisfying

adultlives,undercurrentsystemsofcarepeopleontheautismspectrumareathighriskofpoor

adultoutcomes(Howlin&Moss,2012).Theseincludesocialisolation,educationaland

occupationalunder-attainment,difficultyestablishingindependentliving,poorqualityoflife

andincreasedriskofanearlydeath(Brughaetal.,2011;Howlin&Moss,2012;vanHeijst&

Guerts,2015;Schendeletal.,2016).Inthecurrentstudyweseektoinvestigatethelink

betweenautismandadifferentadultoutcome,namelyhomelessness.Thishasreceivedvery

limitedattentionintheempiricalliteraturetodate,andmaywellrepresentanimportantpartof

thepictureofadultoutcomesofautisticpeople.

1Inthispaper,weusetheterm‘autism’asadirectsynonymfortheDSM-5diagnosticentityof

‘autismspectrumdisorder’(ASD).WehavechosennottousethetermASD,aswedonotaccept

theassumptionitconveys,thatautismisinherentlyastateofmentaldisorder.

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Homelessnessisanumbrellatermwhichcoversarangeofdifferentsituations.Itreferstorough

sleepers,thatispeoplewhosleeporbeddownintheopenair,orinbuildingsorotherplaces

notintendedforhumanhabitation(Crisis,2017).Italsoincludespeoplewhodosleepinaplace

designedforhabitation,butwhodonothaveanylegaltitletotheiraccommodationoraccessto

anyprivatespacesfortheirsocialrelations(Fazeletal.,2014).Homelessnessbotharisesfrom

andcontributestovulnerability:ithasseverenegativeeffectsonphysicalandmentalhealth

(Fazeletal.,2014).Ifautisticpeoplearemorelikelytobecomehomeless,itisimportantto

documentthissothatapotentialsubsetofthehomelesspopulationcanbeidentifiedand

appropriateresourcesextendedtothem.Thiswouldalsohelpwiththedevelopmentof

targetedmeasurestohelppreventautisticpeoplebecominghomelessinthefirstplace.

Thecurrentstudyaimstoexploretherelationshipbetweenautismandhomelessness,by

makinganinitialestimateoftheprevalenceofautistictraitsinahomelesspopulation.Thiswork

wasinitiallymotivatedbyanecdotalreportsfromautismcliniciansandkeyworkersina

homelesssupportservicethatratesofautismmaybeelevatedinthispopulation(e.g.,Homeless

Link,2015).Inlinewiththis,thereisindirectempiricalevidencetosupporttheideathatautism

isariskfactorforhomelessness.Autisticadults,comparedtothosewithoutautism,experience

elevatedratesofmentalhealthproblems,greaterdifficultiesattainingindependentliving

conditions,lowereducationalandoccupationalattainment,andahigherriskofsocialisolation

(e.g.,Howlin&Moss,2012;Magiati,Tay&Howlin,2014).Allofthesecharacteristicsareknown

riskfactorsforhomelessness(Fazeletal.,2008,2014).

Weknowofnostudiespublishedinpeer-reviewedjournalstestingdirectlywhetherautism

predisposespeopletohomelessness.However,therearetwostudiesinthe‘greyliterature’

(i.e.,notpublishedinpeer-reviewedacademicjournals)thatsupportthisidea.Inonesmall-

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scaleinternalauditinaUKNationalHealthServicesetting,apsychiatristinvestigatedthe

presenceofautisminagroupof14homelessmenwithsocialdifficulties(NHSDevon,2011).

Sevenmembersofthispreselectedgroupwerejudgedtohaveshownstrongsignsofautism,

basedonanon-standardizedbutthoroughassessmentinvolvinginterviewswith12ofthe14

homelessindividuals,interviewswithworkers,andalsoreviewingcasenotes.Inanotherstudy,

theNationalAutisticSocietyinWalessurveyed415autisticadultsandfamilymembersof

peoplewithautism.Twelvepercentoftheseautisticadultsreportedhavingbeenhomelessat

leastoncesinceleavingschool(Evans,2011).Thesefindingsarebasedonsuboptimalmethods

ofsamplingandmeasurementandhavenotbeensubjectedtopeerreview,andsomustbe

treatedcautiously.Nevertheless,theysuggestthevalueofamoresystematicinvestigationof

thelinkbetweenautismandhomelessness.

Thetaskofassessingratesofautisminahomelesspopulationisdifficult.Diagnosingautismin

adultsisinitselfchallenging(LaiandBaron-Cohen,2015),andhomelessnesscomplicates

assessmentfurther.Theidealprocessofassessingautisminadultsinvolvescombiningthe

resultsfromstandardisedself-report,directobservationandinformantreportmeasurestogain

apictureofcurrentbehaviouranddevelopmentalhistory(NICE,2012).Thisintensiveprocess

requiresahighdegreeofengagementfromthepersonbeingassessed,andfromsomeonewho

knewthemasachild.Difficultieswithengagementareubiquitousinworkwithhomelesspeople

(KrydaandCompton,2009;Olivetetal.,2010)andgaininganykindofhistorycanbeextremely

difficultinthisgroup,astheyhaveoftenlostcontactwithfamilyandfriends(Roll,Toro,and

Ortola,1999).Otherfactorssuchashighratesofsubstancemisuse,mentalhealthproblems,

andadisjointedsocialenvironmentallalsocomplicatetheprocessofassessment(Fazeletal.,

2014).Furthermore,therearenoautismmeasuresthathavebeenvalidatedforusewith

homelesspeople(Sappok,Heinrich,andUnderwood,2015).

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Reflectingthechallengesofassessingautisminhomelesspeople,ourworkhasthefollowing

features.First,wedirectlyacknowledgethatweareunabletoofferdefinitivediagnosesof

autisminthecurrentstudy.Insteadweseektoderiveaninitialestimateofautistictraits,

includingthoseofsufficientqualityandquantitytobesuggestiveofaDSM-5diagnosis.Second,

insteadofusingself-reportand/ordirectobservation,wechosetomeasureautistictraitsby

informantreport,withtheinformantsbeingkeyworkersinahomelesssupportservice.These

arestaffmemberswhoworkdirectlywithhomelessadultstohelpthemmakepositivechanges,

andalsocoordinatetheircontactwithdiverseservices.Inthisrolekeyworkersworkwiththeir

homelessclientsoverasustainedperiodoftimeandgenerallyknowthemwell.Ourdecisionto

useinformantreportwasinresponsetothelikelihoodthatalargeproportionofthehomeless

populationwesampledwouldnotengagewithresearch.Thosewithautisticsocial

communicationdifficultieswouldlikelybeamongtheleastlikelytoparticipate,whichwould

introduceabiasintoanyestimateofprevalence.Asimilarinformant-reportapproachwas

adoptedbyFraserandcolleagues(2012)withanotherhard-to-engagepopulation,whenthey

estimatedautismprevalenceamongstpatientsinyouthmentalhealthservicesbyinterviewing

theirkeyclinicians.Whilstweacknowledgethatthisapproachdoesnotofferagold-standard

autismassessment,itdoesallowustoinvestigatethefullcaseloadofahomelessservice,

therebylimitingsamplingbias.

Athirdkeyfeatureofthisstudyisthat,giventhelackofrelevantmeasuresvalidatedfor

homelesspeople,wecollecteddatausinganin-depthinterview,structuredaccordingtothe

DSM-5descriptionofautismspectrumdisorder.Anymeasureshouldpossessreliabilityand

validity(Streiner,Norman&Cairney,2015).Weassessedtheinter-raterreliabilitybyblind

double-codingarandomselectionofinterviews.Criterionvalidityistheextenttowhicha

measureco-varieswithanothermeasureofthesameconstruct.Inthisstudy,weadministered

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themostappropriateextantautismmeasureforkeyworkerassessmentofautistictraits,the

AutismSpectrumDisorderinAdultsScreeningQuestionnaire(Nylander&Gillberg,2001);and

checkedhowthiscorrelatedwithoutcomesfromoursemi-structuredDSM-5interview.

Constructvalidityistheextenttowhichaninstrumentshowsthepatternofassociationwith

othermeasuresthatwouldbepredictedbasedonwhatweknowabouttheconstructbeing

measured(Barker&Pistrang,2015).Wemadethreeaprioriconstructvalidityhypotheses.First,

sinceautismisassociatedwithhigherriskofsocialisolation(Grayetal.,2014),wepredicted

thatiftheinterviewpossessesvalidity,thosewithhighautismtraitscoresshouldshowelevated

levelsofsocialisolation.Second,wepredictedthathighautismtraitscoreswouldbeassociated

withlowerlevelsofsubstanceabuseinthehomelesspopulation.Thiswasbasedonreports

fromhomelessnessexpertsweconsultedthat,comparedtothenon-autistichomeless

population,theirautistichomelessclientsarelesslikelytoabusesubstances.Insupportofthis

isthemeta-analyticfindingthatratesofdrugdependence(24.4%,95%CI[13.2-35.6])and

alcoholdependence(37.9%,95%CI[27.8,48.0])areveryhighinthegeneralhomeless

population(Fazeletal.,2008).Bycontrast,suchproblemsaremuchlesscommonamongst

autisticadults,asshownbyarecentwhole-populationstudythatfound3.4%oftheirautistic

participantshadsubstance-userelatedproblems(Butwickaetal,2017).Ourthirdconstruct

validityhypothesisconcernednon-autisticpsychopathology.Mentalhealthproblemsarevery

commonamongsthomelesspeople,andsuchdifficultiescouldartificiallyinflatescoresonany

measureofautistictraits.Forexample,ifapersonissociallywithdrawnduetopsychosisor

socialanxiety,thiscouldmistakenlybetakenasasymptomofautisticsocialimpairment.

Therefore,wereasonedthatifourinstrumenthasconstructvalidity,itwillnotbestrongly

associatedwithnon-autisticmentalhealthdifficultiesinthehomelesspopulation.

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Insummary,ouroverallaimistoderiveaninitialestimateoftheprevalenceofautistictraitsina

homelesspopulationusinginformantreports.Tothisendwesoughttoaddressthefollowing

questions:

1. DoestheDSM-5keyworkerinterviewthatweusedtoevaluateautistictraitsshowinter-

raterreliability?

2. DoestheDSM-5interviewshowcriterionvalidity,asindicatedbyagreementwith

anotherprofessional-reportmeasureofautistictraits?

3. DoestheDSM-5keyworkerinterviewshowconstructvalidity,asindicatedbythosewith

higherautistictraitscores,comparedtothosewithlowerautistictraitscores,being

moresociallyisolated,lesslikelytoabusesubstances,andhavingequivalentlevelsof

mentalhealthdifficulties?

4. Whatproportionofthecaseloadofalong-termhomelessservicehaveelevatedlevelsof

informant-reportedautistictraits,consistentwithaDSM-5diagnosisofautism?

METHODS

Procedure

ThestudywasbasedinahomelessnessoutreachteaminanurbanareaintheUK.Inthisteam,

eachhomelesspersonhasakeyworker,amemberofstaffwhocoordinatestheircontactwith

servicesandworksdirectlywiththemoverasustainedperiodoftime.Atthestartofthis

project,theresearchteamprovidedanautismtrainingworkshopforthekeyworkerstoimprove

thequalityofreporting;toreducebiasesthatcouldarisefromvariationsinkeyworkers’autism

knowledge;andtoengagethekeyworkersintheproject.Thistrainingworkshopincludeda

presentationandstructuredcasediscussionfacilitatedbytheresearchteam,andlastedtwoand

ahalfhours.Subsequently,allkeyworkersagreedtoparticipate.Thisinvolvedthemcompleting

aseparateinterviewforeachoftheirhomelessclients.Theonlyhomelessclientswhowerenot

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thefocusofaninterviewwerethosebornoutsideoftheUKandtheRepublicofIreland.We

suspectthathomelessnessforthosebornoutsidetheUKandIreland,includingrefugees,isa

distinctphenomenon,intermsofitscausesandcharacteristics(Fitzpatrick,Johnsen,and

Bramley,2012;Phillips,2006).

ThisstudyreceivedethicalapprovalfromtheUniversityCollegeLondonResearchEthics

Committee,reference8359/001.Allkeyworkerswereprovidedwithaninformationsheetand

consentform.Wefollowedprocedurestoprotecttheprivacyandconfidentialityofthe

homelesspeoplewhowerethefocusoftheresearchinterviews.Thehomelesspeoplewerenot

identifiabletotheresearchteam:wewerenottoldnamesoranyotheridentifyinginformation

suchasdateofbirth.

Thejointfirstauthorsconductedtheinterviews.Atthetimeoftheresearchtheywereclinical

psychologytraineesworkingaspsychologistsintheUKNationalHealthServiceandstudyingfor

theirdoctorateinclinicalpsychology.Thisroleinvolvesextensivegeneraltrainingon

assessment,andtheyalsoreceivedspecialisttraininginautismfromthethirdandfourth

authors(bothexperiencedinthediagnosisofautism),whichincludedfeedbackonpilot

interviewstheyhadcarriedout.

Participants

Ninekeyworkerstookpartinthestudy,ofwhomsixwerefemale.Keyworkerswereaged

between36and57yearsold(averageage=42.6years,SD=6.4).Theamountoftimetheyhad

workedinhomelessnessservicesrangedfrom6-26years(average=15.0years,SD=7.3).The

amountoftimetheyhadworkedintheircurrentrolerangedfrom2.5-8years,withtheaverage

being3.8years(SD=2.0).Keyworkershad,onaverage,11.8(SD=4.5)caseseach.Theamountof

timeclientshadbeenknownbytheirkeyworkersrangedfrom0-19years,withtheaverage

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being2.9years(SD=3.5).Themajorityofthesample(54.1%)wereseenbykeyworkersata

minimumofonceafortnight,10.2%wereseenmonthly,andcontactwasvariableor

intermittentin34.7%ofcases.

Of137homelesspeopleonthecaseload,106werebornintheUKorRepublicofIrelandandso

werethefocusofaninterview.Ofthese,91(85.8%)weremale.Theiraverageagewas48.9

years(SD=12.7),and87.7%wereWhiteBritish.Theaveragelengthofhomelessnesswas11.7

years(SD=8.5).Themostcommonaccommodationsituationswereasfollows:46(43.4%)were

streethomeless;20(18.9%)wereinahomelesshostel;10(9.4%)wereinindependent

accommodation(e.g.,theirownaccommodationtowhichtheyhadlegaltitle);10(9.4%)werein

semi-independentaccommodation(e.g.,accommodationtheyhadlegaltitleto,butwherea

conditionofhavingtheaccommodationwasthattheyengagedwithspecifiedsupport);and9

(8.5%)wereinprison.Theremaining11(10.4%)wereeitherinemergencyaccommodation,

withfriendsandfamily,haddisappearedformorethan90days,orhadtheiraccommodation

situationlistedas‘other’.Sixty-three(59.4%)wereknowntousedrugsand/oralcohol,and34

(32.1%)hadanofficiallydiagnosedmentalhealthcondition,althoughamuchhighernumber

weresuspectedofhavingamentalhealthcondition.

Measures

DSM-5basedsemi-structuredinterview

Weusedkeyworkers’knowledgeoftheirclientstoidentifythosehomelessindividualswith

observabletraitsofautism.Todothiswecreateda‘DSM-5AutisticTraitsintheHomeless

Interview’,whichwecallthe‘DATHI’.Thisallowedustogatherin-depthinformationaboutthe

individual’spresentation.TheDATHIwasdevelopedthroughthefollowingsequentialprocess:1)

consultationwithexpertsonhomelessness,includingthosewithexperienceofworkingwith

autistichomelesspeople;2)goingthroughtheDSM-5criteriaindetailandcreatingadraft

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interview;3)consultationonthisdraftwiththelocalAdultAutismSpecialInterestGroup,which

comprisescliniciansfromseverallocaladultautismassessmentservices;4)Pilotingthemeasure

withkeyworkersfromthehomelessoutreachteam.Ateachstagetheinterviewwasadapted

basedonfeedbackreceived.

TheDATHI,whichispresentedintheonlinesupplementarymaterialsforthisarticle,wasbased

onDSM-5criteriaforautismspectrumdisorder.Ithasseparatesectionsforeachoftheseven

criteria,withgeneralquestionsfollowedbyspecificprompts.Forexample,aquestionabouteye

contact(partofDSM-5criterionA2)wasfollowedbypromptsaboutwhethereyecontactwas

absent,orwhethertheindividualhadafixedgaze.Somequestionswereadaptedtothe

homelessnesscontext,basedontheinformationgainedfromexpertsinthedevelopment

phase.AnexampleofthiswasthatonepromptinthesectionbasedonDSM-5criterionB2asks

aboutritualisedbehaviourinrelationtosleepsites.Thefocusherewasonwhethertherewere

especiallyfixedpatternsofsleepsiteselection,orifthepersonsetuptheirsleepsiteina

ritualisticfashion.

TheDATHIwasscoredbyratingwhetherautismsymptomswerepresentforeachoftheseven

DSM-5criteria.Arangeofscoringoptionswereusedtoensurethatacriterionwasonly

classifiedas‘Present’iftherewasgoodevidencethatthiswasthecase,asweexpectedthat

therewouldbeawidevarietyinpresentationsanditwouldbedifficultinsomecasestodecide

whetherornotaparticularbehaviourwasacharacteristicofautism.Theotherpotentialscoring

optionswere:‘Possiblypresent’,‘Notpresent’,‘Presentbutattributabletocauseotherthan

autism’,and‘Insufficientinformationtoclassify’.

Scoresonindividualcriteriawerecombinedtomakeanestimatedoverallclassificationforeach

homelessperson.Therewerefourpossiblesummaryoutcomes:(1)screenedpositive-high

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likelihoodofDSM-5autism;(2)marginal-mediumlikelihoodofDSM-5autism;(3)screened

negative-lowlikelihoodofDSM-5autism;(4)unclassified–insufficientinformation.Therules

toassigneachofthesesummaryoutcomesareshowninTable1.

[Table1here]

AutismSpectrumDisorderinAdultsScreeningQuestionnaire(ASDASQ)

TheASDASQisaninformant-reportautismscreeningmeasure,developedformentalhealth

clinicianstorateautisticsymptomsoftheirpatients(NylanderandGillberg,2001).Thisasks

questionsabouttheperson’scurrentpresentation,withanswersinayes/noformat.Potential

scoresrangefrom0-9,withhigherscoresindicatingahigherprobabilityofbeingautistic.Given

theprevalenceofmentalhealthconditionsamonghomelesspeople(Fazeletal.,2008)andthe

factthatitisdesignedtobecompletedbyprofessionals,weconsideredthattheASDASQwas

themostsuitableinstrumenttouseinthecurrentstudy,inordertoexplorethecriterion

validityoftheDATHI.

Additionalinformationgatheredtotestconstructvalidity

Informationonmentalhealthandsubstanceusewasgatheredviaastructuredquestionnaire

completedbykeyworkersdrawinguponclient’snotes.Ascoreof1wasgivenformentalhealth

diagnosesifclientshadoneofmoreformaldiagnoses.Substanceusewascodedseparately

whereascoreof1wasgivenfortheuseofalcoholoranyillegaldrugofanyamounttaken

weeklytomonthly.Anadditionalsemi-structuredinterviewwasusedwithkeyworkerstogather

observableinformationabouttheirclients’socialcontacts.Thesequalitativedatawerethen

quantitativelycodedusingcontentanalysis(Elo&Kyngäs,2008),withrespecttofourmain

categoriesofrelationships(partner,family,peerrelationshipsorsociallyisolated).Acodeof1

wasgivenforeachcategoryiftherewasevidenceofacurrentpartner,anypeerrelationship

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including‘drinkingbuddies’oracquaintancesknownthroughdrugtakingandanycontactwith

anyfamilyincludingbytextorphone.Ifapersonscored0onall3categoriestheyweregivena

scoreof1inthetotallyisolatedcategory.Forthiscodingprocess,inter-raterreliabilitywas

calculatedbasedonasecondrater(AC)blindcodingtwentyinterviews,whichhadoriginally

beencodedbyMR.Thisshowedhighlevelofagreementacrossthecategories;partner(κ=1,p

<.0001,CI:1,2),peerrelationships(κ=0.9,p<.0001,CI:0.72,1.62)andfamilycontact:(κ=

0.73,p=.001,CI:0.4,1.13).Wealsogatheredinformationaboutwhetheranyindividualshad

pre-existingdiagnosesofeitherautismorintellectualdisability.

Dataanalysis

Reliabilitycheckingandassigningfinalclassification

Afterclassificationsweremadebytheprimaryresearchers(ACandMR)thereliabilityofthe

DATHIwasinvestigated.Thiswasdonebyselectingallthe‘screenedpositive’and‘marginal’

cases(n=22)andarandomselectionofcasesthathad‘screenednegative’(n=16).Thedecision

toover-selectpositiveandmarginalcases,ratherthantakearandomselectionfromallcases

screened,wasmadetoprovideamorerigoroustestofthereliabilityofthemeasure.

Allwritteninformationcollectedintheassessmentwassharedwiththeraterswhowereblind

toscoresassignedintheDATHI,andtothefinalclassification.Reliabilitywascheckedforeach

ofthesevenDSM-5criteriaandfortheoverallclassificationmade,usingFleiss’skappa(Fleiss

andCohen,1973).Byconventionkappavaluesbelow.20indicatelimitedreliability,.41to.60

‘moderate’agreement,.61to.80‘substantial’agreementand.80to1‘verystrong’agreement

(Landis&Koch,1977).Thereliabilityraters(thethirdandfourthauthors)areexperiencedin

assessingautisminadultsinbothclinicalpracticeandresearch.

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Afterreliabilitycheckingwascomplete,aconsensusdecisionwasmadebythewholeresearch

teamaboutclassificationforthosecaseswheretherewasadisagreementbetweentheoriginal

classificationandthatmadebythereliabilityrater.

Examiningcriterionvalidity

Inadditiontogeneratinganoverallclassificationforeachindividual,classificationsforindividual

DSM-5criteriawereconvertedintonumericalscores.IfanitemontheDATHIscreenedpositive

(classifiedas‘Present’)itwasgivenascoreof2;ifitscreenedmarginal(classifiedas‘Possibly

present’)itwasgivenascoreof1;ifitscreenednegative(classifiedas‘Notpresent’,‘Present

butattributabletocauseotherthanautism’,or‘Insufficientinformationtoclassify’)itwasgiven

ascoreof0.ThesescoreswerethensummedtoprovideanoverallDATHIscore,aswellas

subscalescoresforDSM-5CriterionA(socialcommunication/socialreciprocity)andCriterionB

(restrictive,repetitivepatternsofbehaviour).CorrelationsbetweentheseDATHIscoresandthe

ASDASQwerecalculatedtoexaminecriterionvalidity.

Examiningconstructvalidity

TheconstructvalidityoftheDATHIwasexaminedbycomparingthoseidentifiedashaving

elevatedautistictraits(i.e.,peoplescreeningpositiveormarginalontheDATHIoverall)with

thosewithoutelevatedautistictraitsonthefollowingvariablesreportedbykeyworkers:(1)

substancemisuse;(2)mentalhealthdiagnoses;(3)socialconnectedness.Groupdifferencesfor

thesecategoricaloutcomeswereexpressedasoddsratioswith95%confidenceintervals.

AllanalyseswereconductedusingIBMSPSSStatisticsversion24.Fleiss’skappawascalculated

usingaplug-inforSPSSdownloadedfromtheIBMdeveloperWorkswebsite(IBMSPSS,2015).

RESULTS

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Figure1showstheprocessofcarryingoutinterviewsandclassification.Ithasdetailsoftotal

numbersscreened,howmanydidnotmeetinclusioncriteria,andwhenreliabilitycheckswere

carriedoutandfinalclassificationsmade.Interviewswithkeyworkerstook20-60minutesper

case,asmorecomplexcasesrequiredmorefollowupquestionsontheDATHI.

[Figure1here]

ReliabilityoftheDATHI

Inter-raterreliabilitycoefficientsareshownforeachDSM-5criterionontheDATHIinTable2.

Accordingtowidelyusedguidelinesforinterpretingkappa(LandisandKoch,1977),inter-rater

reliabilityforcriterionA1(socio-emotionalreciprocity)isinthe‘moderate’range,whilstforthe

othersixDATHIitemsitis‘substantial’.Wealsolookedatinter-rateragreementforoverall

classification,intermsofwhetherornottheDATHIidentifiedanindividualasscreeningpositive.

Fleiss’skappawas0.69,95%CI[0.37,1.0],p<.001,indicatingasubstantiallevelofagreement

betweenratersonthisoutcome(LandisandKoch,1977).

[Table2here]

CriterionvalidityoftheDATHI

TheoverallscorefromtheDATHIwassignificantlyandsubstantiallycorrelatedwiththeASDASQ

(r=.81,p=.01).TheASDASQwasalsosignificantlycorrelatedwiththeDATHIscoresforDSM-5

CriterionA(socialcommunicationandsocialreciprocity,r=.71,p=.01)andforCriterionB

(restrictiveandrepetitivebehaviours,r=.81,p=.01).

Informantreportedautistictraitsinahomelesspopulation

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Table2showstheproportionofhomelesspeoplereportedtoshowdifficultiesconsistentwith

eachDSM-5autismcriterion.ThefullrangeofanswercodesforDATHIitemswereused,butthe

‘Attributabletoothercauses’codewasappliedforonlytwohomelessindividualswhereeither

useofalcoholorapsychoticepisodeledtoaverybriefandobviousshiftintheindividual’s

presentation.Table3givesexamplesofkeyworkerobservationsthatledtoindividualsscoring

positiveforspecificDATHIitems.Insomeinstancessuperficialdetailsinthistablehavebeen

alteredtomaintaintheconfidentialityofclients.

[Table3here]

Item-levelDATHIscoreswereusedtomakeoverallclassificationsaccordingtotheapriori

algorithmdescribedinTable1.Afterthefinalclassification13ofthe106casesscreened

positive,showingsufficientkeyworker-reportedautisticsymptomstomeetDSM-5criteria.This

equatestoaprevalenceinthispopulationof12.3%,95%CI[7.0%,20.4%].Ninecaseswere

identifiedasshowingmarginalevidenceofDSM-5autism,72asnotshowinganyevidenceof

autism,and12asbeinginsufficientlywellknowntoservicestobegivenaclassification.Table4

givesbasicdemographicdetailsandlengthofhomelessnessforeachclassification.

SupplementaryTableS1showstheprofileofautisticsymptomsontheDATHIforeachindividual

whoscreenedpositiveormarginalforautismtraits.

[Table4here]

Characteristicsofhighandlowautismtraitsscorers–constructvalidityoftheDATHI

AsisshowninTable5,inlinewithourconstructvaliditypredictions,homelesspeoplewhowere

identifiedbytheDATHIashavingelevatedautistictraits(i.e.,whoscreenedpositiveormarginal)

weremoresociallyisolatedthanlowtraitscorers.Theywerelesslikelytohaveareported

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substanceabuseproblem.AutistictraitsontheDATHIwerenotassociatedwithhavinganon-

autisticmentalhealthdiagnosis.Withregardstointellectualdisability(ID),fourpeopleoutof

thetotalsamplewereknowntohaveIDdiagnoses.Oneofthesescreenedpositiveonthe

DATHI,threescreenednegative.Oneindividualwasreportedashavingapre-existingdiagnosis

ofautism,andthispersonscreenedpositiveontheDATHI.

[Table5here]

DISCUSSION

Wesoughttoinvestigateapossiblelinkbetweenautismandhomelessness,bygatheringinitial

evidenceastotheprevalenceofautistictraitsinhomelesspeople.Wedevelopedaninterview

tobeadministeredtokeyworkers,basedonDSM-5diagnosticcriteria,andusedthistoscreen

theentirecaseloadofahomelessnessserviceinalargeEnglishcity.Therewasevidencein

supportofthereliabilityandvalidityoftheDSM-5interviewwedeveloped.Accordingtoreports

ofkeyworkers,12.3%ofhomelesspeoplehadarangeofautistictraitsconsistentwithmeeting

DSM-5diagnosticcriteria.Thisissubstantiallyhigherthanthegeneralpopulationautism

prevalenceof1%(Brughaetal.,2016).Ratesofautismmaythereforeberaisedinthishomeless

population,andfurtherinvestigationiswarrantedtounderstandlinksbetweenautismand

homelessness.

ReliabilityandvalidityofDATHI

Toourknowledge,thereisnopriorresearchinpeer-reviewedjournalsonautismand

homelessness.Thislikely,inpart,reflectstheconsiderablechallengesofassessingautismin

homelessadults.Manyhomelesspeoplearereluctanttoengagewithprofessionals,reports

fromrelativesareoftenimpossibletoattain,presentationsarecomplicatedbyco-occurring

Autism (2018)

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difficulties(e.g.,mentalhealthproblems,substancemisuse),andnohomeless-specific

measurementinstrumentshavebeenvalidated(KrydaandCompton,2009;Olivetetal.,2010;

Fazeletal.,2014;Sappoketal.,2015).Toaddresssomeofthesechallengeswecollecteddata

usingakeyworkerinterview,whichwecallthe‘DSM-5AutisticTraitsintheHomelessInterview’

(DATHI).Wechosetouseaninterview,ratherthanaquestionnaireordirectobservationtool,to

allowforin-depthconsiderationofwhetherparticularbehavioursareindicativeofautism.For

example,theback-and-forthdiscussionbetweeninterviewerandintervieweecanhelpboth

partiesreachadecisionaboutwhetheranindividual’slackofeyecontactispervasiveacross

situations,oronlyoccurswhenthatpersonisundertheinfluenceofsubstances.Ouradoption

ofakeyworkerinterviewalsoallowedustoscreenanentirecaseloadofhomelesspeopleinone

service,thusminimisingsamplingbiasandincreasingthegeneralizabilityofourfindings.This

approachwasmadepossiblebythefactthatintheservicewebasedthisstudy,itwasthenorm

forkeyworkerstohavelongstanding(mean=2.9years)relationshipswiththeirhomelessclients.

Giventhatiswasdesignedforthecurrentstudy,acrucialquestioniswhethertheDATHIis

reliableandvalid.Toinvestigatereliability,wemeasuredagreementbetweenblindedraterson

asubsampleofinterviews.Thiswasastringenttestofinter-raterreliabilityaswedeliberately

over-sampled‘marginal’cases.ForallbutoneoftheDATHI’sitems(eachofwhichcorresponds

toaDSM-5criterionforautism),inter-rateragreementwas‘substantial’,withtheotheritem

(A1-‘social-emotionalreciprocity’)showinga‘moderate’levelofagreement.Further,whenwe

consideredtheinstrument’sabilitytodistinguishbetweenthosewhoscreenedpositivefor

autismandthosewhodidnot,inter-rateragreementwas‘substantial’(Kappa=.69).These

findingssuggestthattheDATHIhasadequatereliability.

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ThecasefortheDATHI’scontentvalidityissupportedbythefactthatitwascloselybasedon

DSM-5diagnosticcriteriaforautismspectrumdisorder.Itsfacevaliditywascheckedby

receivingcommentsondraftsfromhomelessnessandautismexperts,andbypilotingthe

interviewwithkeyworkers.WehaveincludedacopyoftheDATHIinsupplementarymaterials

forthispaper,andalsopresentexamplesofbehaviourscodedinthisstudyinTable4,toallow

readerstomakeuptheirownmindsaboutcontentandfacevalidity.

Initialevidenceforcriterionvaliditycomesfromthehighlevelsofassociationwithanother

professional-reportmeasureofautismtraits,theASDASQ(Nylander&Gillberg,2001).We

acknowledgethatthisisnotanespeciallystrongtestofcriterionvalidity,astheASDASQisa

screeningmeasure,andwasdesignedforpsychiatricpopulations,nothomelesspeople.

However,asouraimwastobegintodevelopanevidencebaseinthisareaweconsideredthat

resultsfromtheASDASQwouldatleastprovidesomeinformationregardingthecriterion

validityoftheDATHI.

OnechallengetotheDATHI,andanyassessmentofautisminhomelesspeople,isthehighlevel

ofmentalhealthdifficultiesandsubstanceabuseproblemsinthispopulation.Theriskisthat

behaviours,suchassocialwithdrawaloratypicalnon-verbalbehaviour,couldbemistakenly

labelledasautisticinnature,whenreallytheyreflectamentalhealthproblemortheeffectsof

substancemisuse.ThereforeitisreassuringthatinthisstudyhigherDATHIscoreswerenot

associatedwithhigherratesofdiagnosedmentalhealthproblems.Alsotherewasaninverse

relationshipbetweenreportedsubstanceabuseandautistictraits.Thesefindingssupportthe

constructvalidityoftheDATHI.Also,ourpredictionthathomelesspeoplewithhigherDATHI

scoreswouldbeespeciallysociallyisolatedwassupportedbythedata,andthisprovidesfurther

evidencefortheinterview’sconstructvalidity(Howlin&Moss,2012).

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Autistictraitsandhomelessnesspeople

GiventheaboveinitialevidencethattheDATHIisanadequatekeyworker-reportmeasureof

autisticsymptomsinthehomeless,ourfindingsthatautisticdifficultiesareoverrepresented

amongsthomelessadultsshouldbetakenseriously.Webelievetheyraisethefollowing

possibilitiesthatareworthyoffutureinvestigation.First,autismislikelyariskfactorfor

becominghomeless.Ourfindingshintatonemechanismthatcouldunderpinthis,sincewe

foundthatthosehomelesswithautistictraitsweremoresociallyisolated.Perhapsalackof

socialcapitalmakespeoplemorevulnerabletobecominghomelessinthefaceofotherrisk

factorssuchaspovertyandunemployment(e.g.,Calsyn&Winter,2002).Second,autistic

homelesspeoplemayhaveadistinctprofileofneedsthatimpactontheirdailylifeandchances

ofexitinghomelessness.Forexample,sensorydifficultiescouldmakeithardforsomeonetolive

inanoisyhostel;andexecutiveproblemscouldmakeatransitiontoindependent

accommodationespeciallydifficult.

Limitations

Wehavealreadydiscussedatlengththechallengesofassessingautisminhomelesspeopleand

acknowledgedthatourfindingsarepreliminary.FurthervalidationoftheDATHIwillbevaluable

sothattheinstrumentcanbeusedinfutureinvestigationsofautismandhomelessness.This

shouldinvolvetestingtheDATHIinthehomelesspopulationagainstthecriterionofclinically

diagnosedautism,basedonamulti-disciplinaryassessment(NICE,2012).Suchworkwilllaythe

groundforamorepreciseestimateofthetrueprevalenceofautismamongsthomelesspeople,

andforstudiesthatseektoidentifythecharacteristicsandneedsofautistichomelesspeople.

Therewasasizeablegroupofhomelesspeopleinthisstudywhoweresopoorlyknownto

servicesthatnodatacouldbegatheredaboutthepresenceofASCsymptoms.Theyreceivedthe

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20

classification‘insufficientinformationtoclassify’.Theseindividualsingeneralactivelyavoided

contactwithkeyworkers,andwhilethiscouldhaveawidevarietyofcausesitseemsplausible

thatthiswouldbethetypeofbehaviouranautisticpersonmightdisplay.Thismaymeanthat

ourestimateofprevalenceistoolow.

Withregardstothegeneralisabilityofourfindings,weavoidedsamplingbiaswithrespectto

ourtargetpopulation,whichwasalltheUKandRepublicofIreland-bornclientsofaspecific

Englishhomelessnessservice.Nevertheless,thistargetpopulationisnotperfectly

representativeofthegeneralhomelesspopulation,sincetheycomefromaserviceforthelong-

termhomeless,whotendtohavemorecomplexpresentations(Fazeletal.,2014).Futurework

shouldinvestigateautisminmorediversehomelesspopulations.

Clinicalimplicationsandfuturedirections

Thisstudyhasprovidedinitialevidencethatratesautistictraitsareraisedinhomeless

populations.Whilethiscannotbemorethanatentativeconclusion,thiswouldbeconsistent

withthewell-evidencedpooroutcomesforadultswithASC(HowlinandMoss,2012;

Steinhausenetal.,2016).LaiandBaron-Cohen(2015)refertoa‘lostgeneration’ofadultswith

ASCwhodidnotreceiveadiagnosisbecauseoflackofknowledgeaboutthecondition,andthe

individualswehaveidentifiedmaybepartofthisgroup.

Ifautisticdifficultiesarecommonamonghomelesspopulationsthishasimportantimplications.

ManypeoplearehomelessintheUK;themostrecentestimateisthattherearealmost5000

roughsleepersatanyonepoint(MinistryofHousing,CommunitiesandLocalGovernment,

2017),andthereisamuchlargergroupofpeoplewithnostableaccommodationwhoare

termedthe‘hiddenhomeless’(Crisis,2017).Theremaythereforebeaconsiderablenumberof

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homelessautisticadultswhoarenothavingtheirneedsmet,andwhoareinanextremely

vulnerableposition.

Someorganisationshaverecentlydevelopedwaysofsupportinghomelessautisticadults,and

theyhaveprovidedanecdotalevidenceofsuccess(e.g.,HomelessLink,2015).These

interventionshaveusedexpertisefromtheautismfieldtoinformkeyworking,andrelatively

straightforwardadaptationshavereportedlyallowedtheengagementofadultswhohad

previouslyrefusedsupport.Itwillbevaluabletomanualiseandempiricallytestsuch

interventions,tobegintobuildanevidencebaseforsupportingautistichomelesspeople.Also,

itwillbeimportanttoresearchpathwaysintohomelessnessforautisticpeople,tounderstand

themechanismsofrisk.Thiscanthenbeusedtodesignpreventativestrategiestohelpautistic

adultsavoidhomelessness.

ACKNOWLEDGEMENTS

Theauthorswishtothankalltheworkersatthehomelessserviceinwhichthisprojectwas

basedfortheirsupportandenthusiasm,andforbeingsogenerouswiththeirtimeand

expertise.

FUNDING

ThisworkwaspartlysupportedbystudentshipstoAlasdairChurchardandMoragRyderfrom

HealthEducationEngland.

Autism (2018)

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SUPPLEMENTARYMATERIALSANDACCESSINGRESEARCHMATERIALS

Themaininterview(theDATHI)usedinthisresearchhasbeenuploadedinsupplementary

materials.Otherquestionnairesusedanddatarelatingtothestudycanbeaccessedby

contactingAlasdairChurchard.

Autism (2018)

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Table1–MethodfordeterminingoverallclassificationontheDSM-5AutisticTraitsintheHomelessInterview(DATHI)Classification ScoringcriteriaScreenedpositive/present SectionA:3items=presentORatleast2items=presentAND1item=possiblypresent

ANDSectionB:Atleast2items=presentOR1item=presentANDatleast2items=possiblypresent

Screenedmarginal/possiblypresent SectionA:Atleast3items=possiblypresentANDSectionB:Atleast2items=possiblypresent

Screenednegative/notpresent Doesnotmeetcriteriafor‘Present‘or‘Possiblypresent’Screenednegative/insufficientinformationtoclassify

Clientissopoorlyknowntoservicesthatanyattempttomatchtheirbehaviourtocriteriawouldbeaguess(thissameclassificationwillbeseenonindividualitems).

Table2–ItemscoresandInter-raterreliabilityfortheDSM-5AutisticTraitsintheHomelessInterview(DATHI)Criterion Averagescore

(SD)Percentageofcasesineachclassification Fleiss’skappa

(95%CI) Present Possibly

presentNotpresent Attributableto

othercausesInsufficientinformation

A1:social-emotionalreciprocity

0.50(0.78) 17.9 14.2 55.7 0.9 11.3 0.51(0.30,0.71)

A2:nonverbalcommunication

0.48(0.73) 14.2 19.8 53.8 0.9 11.3 0.65(0.44,0.87)

A3:relationship 0.58(0.79) 18.9 19.8 48.1 0 13.2 0.62(0.40,0.84)

B1:stereotyped/repetitivebehaviours

0.33(0.66) 10.4 12.3 66.0 0 11.3 0.64(0.42,0.85)

B2:inflexibility 0.39(0.68) 11.3 16.0 57.5 1.9 13.2 0.69(0.47,0.90)

B3:fixatedinterests 0.29(0.65) 10.4 8.5 67.9 1.9 11.3 0.64(0.43,0.85)

B4:sensorydifferences 0.25(0.59) 7.5 10.4 69.8 0 12.3 0.65(0.44,0.87)

Note:Averagescorecomputedaccordingtofollowingprocedure:itemscodedas‘Present’givenascoreof2;coded‘Possiblypresent’givenascoreof1;coded‘Notpresent’,‘Presentbutattributabletocauseotherthanautism’,or‘Insufficientinformationtoclassify’givenascoreof0.

Table3–Examplesofkeyworkers’responsesscoringaspresentontheDSM-5AutisticTraitsintheHomelessInterview(DATHI)

Criterion Examplesofbehavioursconsideredconsistentwithautistictraits

A1:Deficitsinsocial-emotionalreciprocity

Manypausesinconversation,wouldnotsayhellotosomeonetheydonotknow.

Cannotsay“howareyou?”asfindsthisinsincere.One-sidedconversationsanddoesnotrespondtoasmile.

Doesnotinitiatesocialinteractionanddisplaysrigidsmilewhengreeted.Givestangentialresponsesandspeaksinstiltedsentences.

A2:Deficitsinnonverbalcommunicativebehaviorsusedforsocialinteraction

Peculiarexpressionwitheyesclosedandmouthopen,displayswhatappearstobealearntsmile.

Noeyecontact,blankfacialexpression,hastobetoldwheninteractionsarefinishedaswouldnotpickuponthisotherwise.

Difficulttotellhowtheyarefeelingfromtheirfacialexpression,doesnotuseorpickuponbodylanguage.

A3:Deficitsindeveloping,maintaining,andunderstandingrelationships

Actsthesameindifferentcontexts.Difficultiesinsocialinteractionledtoleavingaccommodation.

Nofriendshipsorinterestdisplayedinmakingfriends,actsthesametoeveryonetheymeet.

Nointerestshowninmakingfriends,smalltalk.Oftenrudeandaggressiveininteractions.

B1:Stereotypedorrepetitivemotormovements,useofobjects,orspeech

Playswithcuffsandrubslegsallthetime,movespapersrepeatedlyinandoutofenvelope.Seemslikethereisarhythmtothesebehaviours.

Repeatedlymovesarmsinaveryparticularway.Speaksinanold-fashionedway,stereotypedold-fashionedwayofsayinggoodbye.

Describedastalkinglikeacharacterfromanineteenthcenturynovel.Consistentlyusesunusualnameforpeopleinauthority.

B2:Insistenceonsameness,inflexibleadherencetoroutines,orritualizedpatternsofverbalornon-verbalbehavior

Roompreciselyorderedwithsimilaritemsplacedinrows,butextremelydirty.

Itemsorganisedinrowsinroom.Dayfollowspreciseroutineofwhentheysleep,watchTV.Alwaystakesameroutetoshopandhasrulesaboutwhereshoppingcanbeplacedinflat.

Possessionsorganisedverypreciselyonshoppingtrolley,wouldtakethisonsamerouteeachday.Whentrolleywasstolenwasdevastated.

B3:Highlyrestricted,fixatedintereststhatareabnormalinintensityorfocus

Talksalotaboutfood,verypickyaboutfoods,whenshoppingwillstareatoneproductforalongtimereadingallingredients.

Everythingtheybuyhasaparticularanimalonit.Likesonecolouragreatdeal,paintedtheirroomanintenseshadeofthiscolour.

Makeslistsofobscuremusicians,hasalargecollectionofbrokenelectronics.

B4:Hyper-orhyporeactivityto Whenfirealarmwentoff Sensitivetotextureofclothing, Oversensitivetosoundandlight,

sensoryinputorunusualinterestsinsensoryaspectsoftheenvironment

unexpectedlyseemedliketheywouldscream,alwayshascurtainsclosed,burnthandbadlybutseemedunder-reactivetopain(waitedoneweektoseektreatment).

checksbeforepurchasinganything.Attractedbyflashinglight.HasTVonveryloud,whileinhospitalwouldhaveTVscreenveryclosetoface.

doesnotlikeTVbeingleftonwhenisinofficewithkeyworker,refusedownTV.Complainsaboutnoisesotherscannothear.

Table4-DemographicdetailsandlengthofhomelessnessbyclassificationonDSM-5AutisticTraitsintheHomelessInterview(DATHI)

DATHIclassification Gender Meanage(SD) Meanlengthofhomelessnessinyears(SD)

Female Male Screenedpositive/present 2 11 53.5(14.6) 11.8(10.9)Screenedmarginal/possiblypresent 0 9 50.4(10.1) 17.8(9.9)Screenednegative/notpresent 12 60 46.8(12.4) 11.0(8.1)Screenednegative/insufficientinformationtoclassify

1 11 55.9(11.9)

11.4(6.3)

Table5–ComparisonofthecharacteristicsofcaseswithandwithoutelevatedautistictraitsontheDSM-5AutisticTraitsintheHomelessInterview(DATHI)

Noelevatedautistictraits

Elevatedautistictraits

Oddsratio Significance 95%CI

n=72 n=22 Lowerbound UpperboundSocialnetworksize

Inaromanticrelationship 18 3 0.47 0.271 0.13 1.79Friends 57 11 0.26 0.010 0.10 0.72Family 37 4 0.21 0.010 0.06 0.68

Totallyisolated 11 10 4.62 0.005 1.61 13.29Diagnosedmentalhealthcondition 26 8 1.01 0.983 0.37 2.73Drugandalcoholuse 56 12 2.92 0.037 1.07 7.98Note:Elevatedautistictraitsdefinedas‘screenedpositive’or‘marginal’ontheDATHI

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Figure1–Screening,reliabilitychecking,andclassificationprocess