asma y estatus socieconómico

8/14/2019 Asma y estatus socieconmico

1/23

This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formattedPDF and full text (HTML) versions will be made available soon.

Individual-level socioeconomic status is associated with worse asthmamorbidity in patients with asthma

Respiratory Research2009, 10:125 doi:10.1186/1465-9921-10-125

Simon L Bacon ([email protected])Anne Bouchard ([email protected])Eric B Loucks ([email protected])Kim L Lavoie ([email protected])

ISSN 1465-9921

Article type Research

Submission date 5 July 2009

Acceptance date 17 December 2009

Respiratory Research
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


2/23

Individual-levelsocioeconomicstatusisassociatedwithworseasthma

morbidityinpatientswithasthma

SimonL.Bacon1,2,3,AnneBouchard1,4,EricB.Loucks5,KimL.Lavoie1,2,4

1MontrealBehaviouralMedicineCentre,DivisionofChestMedicine,ResearchCenter,Hpitaldu

Sacr-CurdeMontralaUniversityofMontralaffiliatedhospital,5400GouinWest,Montral,

Qubec,H4J1C5,Canada

2DepartmentofExerciseScience,ConcordiaUniversity,7141SherbrookeSt.West,Montreal,

Quebec,H4B1R6,Canada

3MontrealBehaviouralMedicineCentre,ResearchCenter,MontrealHeartInstituteaUniversityof

Montralaffiliatedhospital,5000Belanger,Montreal,Quebec,H1T1C8,Canada

4DepartmentofPsychology,UniversityofQuebecatMontreal(UQAM),P.O.Box8888,Succursale

Center-Ville,Montreal,Quebec,H3C3P8,Canada

5DepartmentofCommunityHealth,EpidemiologySection,CenterforPopulationHealth&Clinical


3/23

Abstract

Background

Lowsocioeconomicstatus(SES)hasbeenlinkedtohighermorbidityinpatientswithchronic

diseases,butmaybeparticularlyrelevanttoasthma,asasthmaticsoflowerSESmayhavehigher

exposurestoindoor(e.g.,cockroaches,tobaccosmoke)andoutdoor(e.g.,urbanpollution)

allergens,thusincreasingriskforexacerbations.

Methods

ThisstudyassessedassociationsbetweenadultSES(measuredaccordingtoeducationallevel)

andasthmamorbidity,includingasthmacontrol;asthma-relatedemergencyhealthserviceuse;

asthmaself-efficacy,andasthma-relatedqualityoflife,inaCanadiancohortof781adult

asthmatics.Allpatientsunderwentasociodemographicandmedicalhistoryinterviewand

pulmonaryfunctiontestingonthedayoftheirasthmaclinicvisit,andcompletedabatteryof


4/23

independentofdiseaseseverity.ResultsareconsistentwithpreviousstudieslinkinglowerSESto

worseasthmainchildren,andaddasthmatothelistofchronicdiseasesaffectedbyindividual-

levelSES.


5/23

Background

Asthmaisachronicdisorderoftheairwayscharacterizedbyreversibleandintermittentairway

obstruction,airwayinflammation,andhyper-reactivityoftheairwaysinresponsetoavarietyofstimuli

(e.g.,dust,animalhair,smoke,andairbornepollutants).Despiteimportantadvancesindiagnosisand

treatment,asthmaremainsoneofthemostprevalentchronicrespiratorydisorders,affecting7-10%of

theworldspopulation.Ratherthandecreasing,prevalenceratesofasthmaoverthepastthree

decadesareactuallyrisinginallage,sex,andracialgroupsinNorthAmerica[1].

Theglobalburdenofasthmaappearstoberelatedtopoorasthmacontrol,whichisassociated

withmorefrequentasthmasymptomatologyandbronchodilatoruse,worsepulmonaryfunction,

greateremergencyhealthserviceutilization,andgreaterfunctionalimpairment(absenteeism,

participationinsocialactivities)[2,3].InCanada,asthmaremainspoorlycontrolledinnearly60%

ofpatients,whichplacesanexcessburdenonthehealthcaresystem,andaccountsforbetween

250 300 deaths per year [4 5] Given that asthma can be well controlled for the vast majority of


6/23

postalcodestodefinedeprivation)inadults[14,15],lessisknownaboutassociationsbetween

individual-levelSESandasthmainadults.

Thepurposeofthepresentstudywastoassessassociationsbetweenadultindividual-levelSES,

measuredaccordingtoeducationlevel,andseveralmeasuresofasthmamorbidityandhealth,

includinglevelsofasthmacontrol,emergencyhealthserviceuse,asthmaself-efficacy,andasthma-

relatedqualityoflifeinaCanadiancohortofasthmatics.ItwashypothesizedthatSESwouldbe

significantlyandnegativelyassociatedwiththesemeasuresofasthmamorbidityandhealth.

Methods

Studyparticipants

Atotalof781consecutiveadultswithphysician-diagnosedasthma(confirmedbychartevidenceofa

20%fallinforcedexpiratoryvolumein1second(FEV1)aftermethacholinechallengeand/or

bronchodilatorreversibilityinFEV1of>20%predicted[16])wererecruitedfromtheoutpatientasthma


7/23

patientswereexcludedfromanalysesduetoincompleteormissingdata,yieldingafinalsampleof781

patients.ThisprojectwasapprovedbytheEthicsCommitteeofHpitalduSacr-CurdeMontral,

andwrittenconsentwasobtainedfromallparticipants.

StudyDesign

Thiscross-sectionalstudywasconductedaspartofalargerstudyevaluatingtheprevalenceand

impactofpsychiatricdisordersamongadultasthmatics[17].Briefly,patientswerescreenedto

determineeligibilityonthedayoftheirregularasthmaclinic.Allpatientsunderwenta

sociodemographicinterview(includingquestionsabouteducationalattainment),andamedical/asthma

historyinterview(includingassessmentsofheightandweightforthecalculationofbodymassindex,

BMI)followedbyabriefpsychiatricinterview(PrimaryCareEvaluationforMentalDisorders,PRIME-

MD)thatwasadministeredbyatrained,clinicalresearchassistant.SESwasmeasuredaccordingto

educationallevel(totalnumberofyearscompleted),whichisoneofthemostcommonmeasuresof

individual-levelSES[18].EducationalattainmentisfrequentlyusedasameasureofSES,becauseit

i t bl ti lik ti d i th t fl t t th lif F th


8/23

QuestionnaireandPsychologicalMeasures

AsthmaControlQuestionnaire(ACQ):

TheACQ[20]isa7-itemself-reportquestionnairethatassesseslevelsofasthmacontrolinthelast

weekaccordingtostandardcriteriaspecifiedbyinternationalguidelines[2].Itemsareratedona7-

pointscale,where0indicatesgoodcontroland6indicatespoorcontrol,toyieldameanscoreoutof6.

Patientsareaskedtoreporttheirsymptoms,limitationsintheirdailyactivities,andbronchodilatoruse

inthelastweek.FEV1%predicted)wascalculatedfromthepulmonaryfunctiontest.TheACQhas

demonstratedexcellentmeasurementproperties,hasbeenvalidatedinCanadianFrench,andscores

of0.8indicatepoorlycontrolledasthma[21].Forthecurrentstudy,theinternalconsistencyofthe

questionnairewashigh(Cronbachs=.84).

AsthmaSelf-EfficacyScale(ASES):

TheASES[22]isan80-itemself-reportquestionnairethatassessesasthmaticsbeliefsorconfidence

intheirabilitytosuccessfullycontroloravoidanasthmaattackinavarietyofsituations.TheASESis

t d 5 i t l h 0 i di t fid d 4 i di t fid t t i ld


9/23

PrimaryCareEvaluationofMentalDisorders(PRIME-MD):

ThePRIME-MD[26]assessestheprevalence(i.e.,presentornot)ofmood(majorandminor

depression,dysthymia)andanxiety(panicdisorders,generalizedanxietydisorder,otheranxiety

disorder)usingalgorithmsthatarebasedonDSM-IV.Ithasbeenshowntobeofcomparable

sensitivity,specificityandreliabilityaslongerstructuredinterviews,andtakesapproximately10to20

minutestoadministerandscore[26].

Analyses

Thoughmainanalyseswereconductedusingbothcontinuousanddichotomousmeasuresof

education,sociodemographic,andmedical/asthmahistorycharacteristicswerepresentedasa

functionoflow(


10/23

Results

Samplecharacteristics

Thefinalsampleof781patientsincluded467(60%)womenwithamean(SD)ageof48.5(14.3)

years.Themean(SD)durationofasthmaforsamplewas18.6(15.2)yearsand71%(n=555)were

atopic.Themean(SD)educationallevelwas12.9(3.6)years(range2-23years)ofschooling.Mean

sample(SD)[range]forACQ,ASESandAQLQscoreswere1.6(1.1)[0.0-6.0],222.3(66.1)[13.3-

320],and5.1(1.2)[1.5-7.0]respectively.Atotalof184(24%)ofthesamplereportedamean(SD)

[range]of2.1(2.0)[1-15]emergencyhealthservicevisitsinthelastyear.Mean(SD)pulmonary

function(%FEV1,%FVC,FEV1/FVC)forthesamplewas78.9(21.8),89.5(19.6),and72.4(14.4)

respectively.

Demographicandmedical/asthmahistorycharacteristics

Demographicandmedical/asthmahistorycharacteristicsasafunctionoflow(


11/23

Inaddition,therewasanapproximate30%reductionintheafteradjustingforcovariates,suggesting

thesevariablesaccountedforsomebutnotalloftheassociationstrength..Therewereno

associationsbetweenSESandAQLQscores.PoissonregressionrevealedthatlowerSESwas

associatedwithgreateremergencyhealthserviceuse,independentofage,sex,asthmaseverity

(estimate=-0.07,SE=0.02,95%CI=-0.10--0.03),andalladditionalcovariates(estimate=-0.05,SE

=0.02,95%CI=-0.09--0.01),withaminimalchangeintheestimate.Logisticregressionanalyses

revealedthatpatientswith


12/23

Thesefindingsareconsistentwithpreviousstudiesfindingsignificantassociationsbetweenlower

childhoodSESandworseasthmamorbidity,includingincreasedprevalenceofasthmaandsevere

asthma[12,13],andincreasedriskofemergencydepartmentvisitsandhospitalizationsforasthma

[29,30].ThesefindingsarealsoinlinewithpreviousstudieslinkinglowerSES(assessedusingarea-

levelandindividual-levelmeasures)toworseasthmamorbidityinadults,includingincreased

prevalenceofasthma[31],greaterasthmasymptomatology[32],andincreasedasthmarelated

hospitalisations[33].However,thisstudyis,toourknowledge,thefirsttoassesstheimpactof

individual-levelSESonmultiplemeasuresofasthmamorbidityinsuchalargeCanadiancohortof

adultasthmatics.AlthoughLyndetal.[34]examinedthelinkbetweenbothindividualandarea-level

measuresofSESandasthmainaCanadiansample,theirsamplesizewasmodest(n=202),andtheir

analysesfocusedonlinksbetweenSESandshort-actingbronchodilatoruseasaproxymeasureof

asthmacontrol.Theirfindingsarestillconsistentwiththoseofourstudy,thoughwewereableto

extendtheirfindingsbyshowingthatasthmaticsoflowerSEShaveworseasthmacontrolaccordingto

theACQandemergencyhealthserviceuse.


13/23

studydidnotcollectdataonmedicationadherence,buttheresultswereindependentofasthma

severity,whichisprimarilyderivedfromtheprescribeddosageofinhaledcorticosteroids.Furthermore,

apreviousstudyhasshownthatSESwasrelatedtoACQscoresindependentofcorticosteroiduse

[40].Thereisalsoevidencethattheunderlyingphysiologicalprocessesseeninasthmaareinfluenced

bySES,whereheightenedinflammatoryresponsestosimilardosesofantigenchallengehavebeen

showninpatientswithlowversushighSES[41,42],whichmaybeaconsequenceoflowSES

individualsoverexpressinggenesregulatingtheirinflammatoryprocesses[43].However,itshouldbe

notedthatthesefindingsaredrawnfromdatainchildrenandneedstobereplicatedinadultsamples.

OneadditionalfindingthatwarrantsdiscussionisthatasthmaticsoflowerSESwerelesslikelytobe

atopic(i.e.,haveallergicasthma)thanasthmaticsofhigherSES.Althoughthiswasnottheprimary

aimoftheanalyses,thisfindingisconsistentwithseveralstudieslinkinglowerSEStolowerincidence

ofallergicasthma[31,32,44,45].Althoughcontroversial,ithasbeensuggestedthatthisrelationship

maybeduetothehygienehypothesis,whichproposesthatthedevelopmentofatopicasthmaand

ll b t d i t l d l hildh d t i t ti l t


14/23

berelatedtoissuesassociatedwiththenatureofthepopulationsassessedandtostudydesign.For

example,Blancetal.[14]recruitedpatientsfrommultipleclinicsviaphysicianreferral,aswellasusing

random-digittelephonerecruitment;whereaswerecruitedconsecutivepatientsfromasingletertiary-

careclinicwhereasthmaisgenerallymoresevereandthusmayreducevariabilityinqualityoflife

measures.TheApteretal.[48]studyfoundthattherelationshipbetweenSESandqualityoflifewas

highlyconfoundedbyrace/ethnicity,withnon-CaucasianshavinglowerSESandpoorerqualityoflife.

WhiletheApteretal.studyconsistedofnearly60%ofnon-Caucasians,thecurrentstudyhasless

than10%non-Caucasions,suggestingthattheresultsreportedbyApteretal.mayhavebeendriven

byrace/ethnicityratherthanSES[49].Inaddition,thesignificantassociationbetweenSESandworse

asthma-specificqualityoflifeinBlancetal.sstudywasobservedusingadifferentmeasureofSES

(i.e.,area-level),andadifferentqualityoflifescale(i.e.,MarksAsthmaQualityofLifeQuestionnaire)

thanthoseusedinthepresentstudy.Assuch,thedisparatefindingsbetweenthesetwostudiesmay

beattributabletothespecificchoiceofmeasures.Furtherreplicationstudiesareneededtoshed

morelightontheassociationbetweenSESandasthma-relatedqualityoflifeinadultsamples.


15/23

thatareassociatedwithSESthatmayhavepartiallyaccountedforourfindingssuchasactual

exposurelevelstoallergens,irritants,andpollutants,andlivingconditions(i.e.,overcrowding)which

mayhaveincreasedtheriskofrespiratoryinfectionsthatconferriskforworseasthmamorbidity[32].

Despitetheselimitations,theresultsofthepresentstudycomplementandstrengthenpreviousreports

byincludingalargecohortofadultasthmaticswithobjectivelyconfirmedphysician-diagnosedasthma

andatopy,andthemeasurementofarangeofasthmamorbidityandhealthmeasuresthatincluded

self-reportedsymptomsandobjectivelymeasuredemergencyhealthserviceutilizationthatwas

verifiedbychartreview.Duetotherangeanddepthofourassessments,wewerealsoabletocontrol

foranumberofpotentialconfounders,includingsmokingstatus,BMI,psychiatriccomorbidity,and

asthmaseverity,whichatteststotherobustnessofthefindings.

Conclusions

Insummary,thisstudyfoundevidenceforanassociationbetweeneducationlevel(whichisindicative

f SES) d th bidit d h lth i l t ti l f C di d lt ith


16/23

Authors'contributions

SLBco-wrotethemanuscript,conductedallstatisticaldataanalyses,andobtainedfundingforthe

study.ABcollectedprimarydataandhelpeddeveloptheconceptualidea.EBLhelpeddevelopthe

conceptualframeworkandprovidedcriticalfeedbackonmanuscriptdrafts.KLLconceivedofthe

study,participatedinitsdesignandcoordination,obtainedfundingforthestudy,andco-wrotethe

manuscript.Allauthorsreadandapprovedthefinalmanuscript.

Acknowledgements

TheauthorsthankGuillaumeLacoste,BA,forhisinvaluableassistancewithdatacollection.

FundingsupportforthisstudywasprovidedbysalaryawardsfromtheFondsdelarechercheen

santduQubec(FRSQ)(SLB&KLL)andtheCanadianInstitutesofHealthNewInvestigator

Award(CIHR)(SLB&EBL),grantsupportfromtheFRSQ(SLB&KLL)andtheMichelAuger

FoundationofHpitalduSacr-CoeurdeMontral(KLL),andscholarshipsupportfromFRSQand

th S i l S i d H iti R h C il (SSHRC) (AB)


17/23

5. AboussafyD,BalterM,GodinG,LavoieKL,KoleyS:Asthma:ThePsychologyof

Compromise.Ottawa:CanadianLungAssociation;2004.

6. CooperR,CutlerJ,Desvigne-NickensP,FortmannSP,FriedmanL,HavlikR,HogelinG,

MarlerJ,McGovernP,MoroscoG,MoscaL,PearsonT,StamlerJ,StryerD,ThomT:

TrendsandDisparitiesinCoronaryHeartDisease,Stroke,andOtherCardiovascular

DiseasesintheUnitedStates:FindingsoftheNationalConferenceon

CardiovascularDiseasePrevention.Circulation2000,102:3137-3147.

7. O'MalleyAS,PhamHH,SchragD,WuB,BachPB:Potentiallyavoidable

hospitalizationsforCOPDandpneumonia:theroleofphysicianandpractice

characteristics.MedCare2007,45:562-570..

8. BrownAF,EttnerSL,PietteJ,WeinbergerM,GreggE,ShapiroMF,KarterAJ,SaffordM,

WaitzfelderB,PrataPA,BecklesGL:SocioeconomicPositionandHealthamong

PersonswithDiabetesMellitus:AConceptualFrameworkandReviewofthe

Literature.EpidemiolRev2004,26:63-77.

9 W i ht RJ Fi h EB P tti th i t t t it i fl i k


18/23

14. BlancPD,YenIH,ChenH,KatzPP,EarnestG,BalmesJR,TrupinL,FriedlingN,Yelin

EH,EisnerMD:Area-levelsocio-economicstatusandhealthstatusamongadults

withasthmaandrhinitis.EurRespJ2006,27:85-94.

15. BoudreauxED,EmondSD,ClarkS,CamargoCA,Jr.:AcuteAsthmaAmongAdults

PresentingtotheEmergencyDepartment:TheRoleofRace/Ethnicityand

SocioeconomicStatus.Chest2003,124:803-812.

16. AmericanThoracicSociety:StandardizationofSpirometry,1994Update.AmJRespir

CritCareMed1995,152:1107-1136.

17. LavoieKL,CartierA,LabrecqueM,BaconSL,LemiereC,MaloJ-L,LacosteG,BaroneS,

VerrierP,DittoB:Arepsychiatricdisordersassociatedwithworseasthmacontroland

qualityoflifeinasthmapatients?RespMed2005,99:1249-1257.

18. KriegerN,WilliamsDR,MossNE:MeasuringsocialclassintheUSpublichealth

resaerch:Concepts,methodologies,andguidelines.AnnuRevPublicHealth1997,

18:341-378.

19 B S B S C b ll T L b M Di B L i K Th i ti


19/23

26. SpitzerRL,WilliamsJB,KroenkeK,LinzerM,deGruyFV,3rd,HahnSR,BrodyD,Johnson

JG:Utilityofanewprocedurefordiagnosingmentaldisordersinprimarycare.The

PRIME-MD1000study.JAMA1994,272:1749-1756.

27. LavoieKL,BaconSL,LabrecqueM,CartierA,DittoB:Bodymassindexisassociated

withworseasthmacontrolandqualityoflifeamongadultasthmapatients.RespMed

2006,100:648-657.

28. PiipariR,JaakkolaJJK,JaakkolaN,JaakkolaMS:Smokingandasthmainadults.Eur

RespJ2004,24:734-739.

29. MaziakW,vonMutiusE,KeilU,HirschT,LeupoldW,RzehakP,BehrensT,WeilandSK:

Predictorsofhealthcareutilizationofchildrenwithasthmainthecommunity.Pediatr

AllergyImmunol2004,15:166-171.

30. CesaroniG,FarchiS,DavoliM,ForastiereF,PerucciCA:Individualandarea-based

indicatorsofsocioeconomicstatusandchildhoodasthma.EurRespJ2003,22:619-

624.

31 B b k L Hj A R F S i l l i h d ll i hi i i


20/23

37. HulshofKF,BrussaardJH,KruizingaAG,TelmanJ,LwikMR:Socio-economicstatus,

dietaryintakeand10ytrends:theDutchNationalFoodConsumptionSurvey.EurJ

ClinNutr2003,57:128-137.

38. ApterAJ,ReisineST,AffleckG,BarrowsE,ZuWallackRL:Adherencewithtwice-daily

dosingofinhaledsteroids.Socioeconomicandhealth-beliefdifferences.AmJRespir

CritCareMed1998,157:1810-1817.

39. JansonC,ChinnS,JarvisD,BurneyP:Individualuseofantiasthmaticdrugsinthe

EuropeanCommunityRespiratoryHealthSurvey.EurRespJ1998,12:557-563.

40. deVriesMP,vandenBemtL,LinceS,MurisJWM,ThoonenBPA,vanSchayckCP:

Factorsassociatedwithasthmacontrol.JournalofAsthma2005,42:659-665.

41. ChenE,HansonMD,PatersonLQ,GriffinMJ,WalkerHA,MillerGE:Socioeconomic

statusandinflammatoryprocessesinchildhoodasthma:theroleofpsychological

stress.JournalofAllergy&ClinicalImmunology2006,117:1014-1020.

42. ChenE,FisherEB,BacharierLB,StrunkRC:Socioeconomicstatus,stress,and

i k i d l i h h P h M d 2003 65 984 992


21/23

48. ApterAJ,ReisineST,AffleckG,BarrowsE,ZuWallackRL:Theinfluenceof

demographicandsocioeconomicfactorsonhealth-relatedqualityoflifeinasthma.

JournalofAllergy&ClinicalImmunology1999,103:72-78.

49. FornoE,CeledonJC:Asthmaandethnicminorities:socioeconomicstatusand

beyond.CurrOpinAllergyClinImmunol2009,9:154-160.

50. Bryant-StephensT:Asthmadisparitiesinurbanenvironments.JournalofAllergy&

ClinicalImmunology2009,123:1199-1206;quiz1207-1198.


22/23

Tables

Table1:Demographicandmedical/asthmacharacteristicspresentedasafunctionofhigh

versuslowSES

Low(


23/23

-22-

Table2:Associationbetweeneducationalattainmentandasthmamorbidityvariables (GLM)

modeladjustment

age,sex,asthmaseverity age,sex,asthmaseverity,BMI,smoking,andpsychiatric

disorder

(SE) F p (SE) F p

ACQ -0.041(0.011) 14.12

asma y estatus socieconómico

Documents